1mbed TLS ChangeLog (Sorted per branch, date)
2
3= mbed TLS 2.16.0 branch released 2018-12-21
4
5Features
6   * Add a new config.h option of MBEDTLS_CHECK_PARAMS that enables validation
7     of parameters in the API. This allows detection of obvious misuses of the
8     API, such as passing NULL pointers. The API of existing functions hasn't
9     changed, but requirements on parameters have been made more explicit in
10     the documentation. See the corresponding API documentation for each
11     function to see for which parameter values it is defined. This feature is
12     disabled by default. See its API documentation in config.h for additional
13     steps you have to take when enabling it.
14
15API Changes
16   * The following functions in the random generator modules have been
17     deprecated and replaced as shown below. The new functions change
18     the return type from void to int to allow returning error codes when
19     using MBEDTLS_<MODULE>_ALT for the underlying AES or message digest
20     primitive. Fixes #1798.
21     mbedtls_ctr_drbg_update() -> mbedtls_ctr_drbg_update_ret()
22     mbedtls_hmac_drbg_update() -> mbedtls_hmac_drbg_update_ret()
23   * Extend ECDH interface to enable alternative implementations.
24   * Deprecate error codes of the form MBEDTLS_ERR_xxx_INVALID_KEY_LENGTH for
25     ARIA, CAMELLIA and Blowfish. These error codes will be replaced by
26     the more generic per-module error codes MBEDTLS_ERR_xxx_BAD_INPUT_DATA.
27   * Additional parameter validation checks have been added for the following
28     modules - AES, ARIA, Blowfish, CAMELLIA, CCM, GCM, DHM, ECP, ECDSA, ECDH,
29     ECJPAKE, SHA, Chacha20 and Poly1305, cipher, pk, RSA, and MPI.
30     Where modules have had parameter validation added, existing parameter
31     checks may have changed. Some modules, such as Chacha20 had existing
32     parameter validation whereas other modules had little. This has now been
33     changed so that the same level of validation is present in all modules, and
34     that it is now optional with the MBEDTLS_CHECK_PARAMS flag which by default
35     is off. That means that checks which were previously present by default
36     will no longer be.
37
38New deprecations
39   * Deprecate mbedtls_ctr_drbg_update and mbedtls_hmac_drbg_update
40     in favor of functions that can return an error code.
41
42Bugfix
43   * Fix for Clang, which was reporting a warning for the bignum.c inline
44     assembly for AMD64 targets creating string literals greater than those
45     permitted by the ISO C99 standard. Found by Aaron Jones. Fixes #482.
46   * Fix runtime error in `mbedtls_platform_entropy_poll()` when run
47     through qemu user emulation. Reported and fix suggested by randombit
48     in #1212. Fixes #1212.
49   * Fix an unsafe bounds check when restoring an SSL session from a ticket.
50     This could lead to a buffer overflow, but only in case ticket authentication
51     was broken. Reported and fix suggested by Guido Vranken in #659.
52   * Add explicit integer to enumeration type casts to example program
53     programs/pkey/gen_key which previously led to compilation failure
54     on some toolchains. Reported by phoenixmcallister. Fixes #2170.
55   * Fix double initialization of ECC hardware that made some accelerators
56     hang.
57   * Clarify documentation of mbedtls_ssl_set_own_cert() regarding the absence
58     of check for certificate/key matching. Reported by Attila Molnar, #507.
59
60= mbed TLS 2.14.1 branch released 2018-11-30
61
62Security
63   * Fix timing variations and memory access variations in RSA PKCS#1 v1.5
64     decryption that could lead to a Bleichenbacher-style padding oracle
65     attack. In TLS, this affects servers that accept ciphersuites based on
66     RSA decryption (i.e. ciphersuites whose name contains RSA but not
67     (EC)DH(E)). Discovered by Eyal Ronen (Weizmann Institute),  Robert Gillham
68     (University of Adelaide), Daniel Genkin (University of Michigan),
69     Adi Shamir (Weizmann Institute), David Wong (NCC Group), and Yuval Yarom
70     (University of Adelaide, Data61). The attack is described in more detail
71     in the paper available here: http://cat.eyalro.net/cat.pdf  CVE-2018-19608
72   * In mbedtls_mpi_write_binary(), don't leak the exact size of the number
73     via branching and memory access patterns. An attacker who could submit
74     a plaintext for RSA PKCS#1 v1.5 decryption but only observe the timing
75     of the decryption and not its result could nonetheless decrypt RSA
76     plaintexts and forge RSA signatures. Other asymmetric algorithms may
77     have been similarly vulnerable. Reported by Eyal Ronen, Robert Gillham,
78     Daniel Genkin, Adi Shamir, David Wong and Yuval Yarom.
79   * Wipe sensitive buffers on the stack in the CTR_DRBG and HMAC_DRBG
80     modules.
81
82API Changes
83   * The new functions mbedtls_ctr_drbg_update_ret() and
84     mbedtls_hmac_drbg_update_ret() are similar to mbedtls_ctr_drbg_update()
85     and mbedtls_hmac_drbg_update() respectively, but the new functions
86     report errors whereas the old functions return void. We recommend that
87     applications use the new functions.
88
89= mbed TLS 2.14.0 branch released 2018-11-19
90
91Security
92   * Fix overly strict DN comparison when looking for CRLs belonging to a
93     particular CA. This previously led to ignoring CRLs when the CRL's issuer
94     name and the CA's subject name differed in their string encoding (e.g.,
95     one using PrintableString and the other UTF8String) or in the choice of
96     upper and lower case. Reported by Henrik Andersson of Bosch GmbH in issue
97     #1784.
98   * Fix a flawed bounds check in server PSK hint parsing. In case the
99     incoming message buffer was placed within the first 64KiB of address
100     space and a PSK-(EC)DHE ciphersuite was used, this allowed an attacker
101     to trigger a memory access up to 64KiB beyond the incoming message buffer,
102     potentially leading to an application crash or information disclosure.
103   * Fix mbedtls_mpi_is_prime() to use more rounds of probabilistic testing. The
104     previous settings for the number of rounds made it practical for an
105     adversary to construct non-primes that would be erroneously accepted as
106     primes with high probability. This does not have an impact on the
107     security of TLS, but can matter in other contexts with numbers chosen
108     potentially by an adversary that should be prime and can be validated.
109     For example, the number of rounds was enough to securely generate RSA key
110     pairs or Diffie-Hellman parameters, but was insufficient to validate
111     Diffie-Hellman parameters properly.
112     See "Prime and Prejudice" by by Martin R. Albrecht and Jake Massimo and
113     Kenneth G. Paterson and Juraj Somorovsky.
114
115Features
116   * Add support for temporarily suspending expensive ECC computations after
117     some configurable amount of operations. This is intended to be used in
118     constrained, single-threaded systems where ECC is time consuming and can
119     block other operations until they complete. This is disabled by default,
120     but can be enabled by MBEDTLS_ECP_RESTARTABLE at compile time and
121     configured by mbedtls_ecp_set_max_ops() at runtime. It applies to the new
122     xxx_restartable functions in ECP, ECDSA, PK and X.509 (CRL not supported
123     yet), and to existing functions in ECDH and SSL (currently only
124     implemented client-side, for ECDHE-ECDSA ciphersuites in TLS 1.2,
125     including client authentication).
126   * Add support for Arm CPU DSP extensions to accelerate asymmetric key
127     operations. On CPUs where the extensions are available, they can accelerate
128     MPI multiplications used in ECC and RSA cryptography. Contributed by
129     Aurelien Jarno.
130   * Extend RSASSA-PSS signature to allow a smaller salt size. Previously, PSS
131     signature always used a salt with the same length as the hash, and returned
132     an error if this was not possible. Now the salt size may be up to two bytes
133     shorter. This allows the library to support all hash and signature sizes
134     that comply with FIPS 186-4, including SHA-512 with a 1024-bit key.
135   * Add support for 128-bit keys in CTR_DRBG. Note that using keys shorter
136     than 256 bits limits the security of generated material to 128 bits.
137
138API Changes
139   * Add a common error code of `MBEDTLS_ERR_PLATFORM_FEATURE_UNSUPPORTED` for
140     a feature that is not supported by underlying alternative
141     implementations implementing cryptographic primitives. This is useful for
142     hardware accelerators that don't implement all options or features.
143
144New deprecations
145   * All module specific errors following the form
146     MBEDTLS_ERR_XXX_FEATURE_UNAVAILABLE that indicate a feature is not
147     supported are deprecated and are now replaced by the new equivalent
148     platform error.
149   * All module specific generic hardware acceleration errors following the
150     form MBEDTLS_ERR_XXX_HW_ACCEL_FAILED that are deprecated and are replaced
151     by the equivalent plaform error.
152   * Deprecate the function mbedtls_mpi_is_prime() in favor of
153     mbedtls_mpi_is_prime_ext() which allows specifying the number of
154     Miller-Rabin rounds.
155
156Bugfix
157   * Fix wrong order of freeing in programs/ssl/ssl_server2 example
158     application leading to a memory leak in case both
159     MBEDTLS_MEMORY_BUFFER_ALLOC_C and MBEDTLS_MEMORY_BACKTRACE are set.
160     Fixes #2069.
161   * Fix a bug in the update function for SSL ticket keys which previously
162     invalidated keys of a lifetime of less than a 1s. Fixes #1968.
163   * Fix failure in hmac_drbg in the benchmark sample application, when
164     MBEDTLS_THREADING_C is defined. Found by TrinityTonic, #1095
165   * Fix a bug in the record decryption routine ssl_decrypt_buf()
166     which lead to accepting properly authenticated but improperly
167     padded records in case of CBC ciphersuites using Encrypt-then-MAC.
168   * Fix memory leak and freeing without initialization in the example
169     program programs/x509/cert_write. Fixes #1422.
170   * Ignore IV in mbedtls_cipher_set_iv() when the cipher mode is
171     MBEDTLS_MODE_ECB. Found by ezdevelop. Fixes #1091.
172   * Zeroize memory used for buffering or reassembling handshake messages
173     after use.
174   * Use `mbedtls_platform_zeroize()` instead of `memset()` for zeroization
175     of sensitive data in the example programs aescrypt2 and crypt_and_hash.
176   * Change the default string format used for various X.509 DN attributes to
177     UTF8String. Previously, the use of the PrintableString format led to
178     wildcards and non-ASCII characters being unusable in some DN attributes.
179     Reported by raprepo in #1860 and by kevinpt in #468. Fix contributed by
180     Thomas-Dee.
181   * Fix compilation failure for configurations which use compile time
182     replacements of standard calloc/free functions through the macros
183     MBEDTLS_PLATFORM_CALLOC_MACRO and MBEDTLS_PLATFORM_FREE_MACRO.
184     Reported by ole-de and ddhome2006. Fixes #882, #1642 and #1706.
185
186Changes
187   * Removed support for Yotta as a build tool.
188   * Add tests for session resumption in DTLS.
189   * Close a test gap in (D)TLS between the client side and the server side:
190     test the handling of large packets and small packets on the client side
191     in the same way as on the server side.
192   * Change the dtls_client and dtls_server samples to work by default over
193     IPv6 and optionally by a build option over IPv4.
194   * Change the use of Windows threading to use Microsoft Visual C++ runtime
195     calls, rather than Win32 API calls directly. This is necessary to avoid
196     conflict with C runtime usage. Found and fixed by irwir.
197   * Remember the string format of X.509 DN attributes when replicating
198     X.509 DNs. Previously, DN attributes were always written in their default
199     string format (mostly PrintableString), which could lead to CRTs being
200     created which used PrintableStrings in the issuer field even though the
201     signing CA used UTF8Strings in its subject field; while X.509 compliant,
202     such CRTs were rejected in some applications, e.g. some versions of
203     Firefox, curl and GnuTLS. Reported in #1033 by Moschn. Fix contributed by
204     Thomas-Dee.
205   * Improve documentation of mbedtls_ssl_get_verify_result().
206     Fixes #517 reported by github-monoculture.
207   * Add MBEDTLS_MPI_GEN_PRIME_FLAG_LOW_ERR flag to mbedtls_mpi_gen_prime() and
208     use it to reduce error probability in RSA key generation to levels mandated
209     by FIPS-186-4.
210
211= mbed TLS 2.13.1 branch released 2018-09-06
212
213API Changes
214   * Extend the platform module with an abstraction mbedtls_platform_gmtime_r()
215     whose implementation should behave as a thread-safe version of gmtime().
216     This allows users to configure such an implementation at compile time when
217     the target system cannot be deduced automatically, by setting the option
218     MBEDTLS_PLATFORM_GMTIME_R_ALT. At this stage Mbed TLS is only able to
219     automatically select implementations for Windows and POSIX C libraries.
220
221Bugfix
222   * Fix build failures on platforms where only gmtime() is available but
223     neither gmtime_r() nor gmtime_s() are present. Fixes #1907.
224
225= mbed TLS 2.13.0 branch released 2018-08-31
226
227Security
228   * Fix an issue in the X.509 module which could lead to a buffer overread
229     during certificate extensions parsing. In case of receiving malformed
230     input (extensions length field equal to 0), an illegal read of one byte
231     beyond the input buffer is made. Found and analyzed by Nathan Crandall.
232
233Features
234   * Add support for fragmentation of outgoing DTLS handshake messages. This
235     is controlled by the maximum fragment length as set locally or negotiated
236     with the peer, as well as by a new per-connection MTU option, set using
237     mbedtls_ssl_set_mtu().
238   * Add support for auto-adjustment of MTU to a safe value during the
239     handshake when flights do not get through (RFC 6347, section 4.1.1.1,
240     last paragraph).
241   * Add support for packing multiple records within a single datagram,
242     enabled by default.
243   * Add support for buffering out-of-order handshake messages in DTLS.
244     The maximum amount of RAM used for this can be controlled by the
245     compile-time constant MBEDTLS_SSL_DTLS_MAX_BUFFERING defined
246     in mbedtls/config.h.
247
248API Changes
249   * Add function mbedtls_ssl_set_datagram_packing() to configure
250     the use of datagram packing (enabled by default).
251
252Bugfix
253   * Fix a potential memory leak in mbedtls_ssl_setup() function. An allocation
254     failure in the function could lead to other buffers being leaked.
255   * Fixes an issue with MBEDTLS_CHACHAPOLY_C which would not compile if
256     MBEDTLS_ARC4_C and MBEDTLS_CIPHER_NULL_CIPHER weren't also defined. #1890
257   * Fix a memory leak in ecp_mul_comb() if ecp_precompute_comb() fails.
258     Fix contributed by Espressif Systems.
259   * Add ecc extensions only if an ecc based ciphersuite is used.
260     This improves compliance to RFC 4492, and as a result, solves
261     interoperability issues with BouncyCastle. Raised by milenamil in #1157.
262   * Replace printf with mbedtls_printf in the ARIA module. Found by
263     TrinityTonic in #1908.
264   * Fix potential use-after-free in mbedtls_ssl_get_max_frag_len()
265     and mbedtls_ssl_get_record_expansion() after a session reset. Fixes #1941.
266   * Fix a bug that caused SSL/TLS clients to incorrectly abort the handshake
267     with TLS versions 1.1 and earlier when the server requested authentication
268     without providing a list of CAs. This was due to an overly strict bounds
269     check in parsing the CertificateRequest message,
270     introduced in Mbed TLS 2.12.0. Fixes #1954.
271   * Fix a miscalculation of the maximum record expansion in
272     mbedtls_ssl_get_record_expansion() in case of ChachaPoly ciphersuites,
273     or CBC ciphersuites in (D)TLS versions 1.1 or higher. Fixes #1913, #1914.
274   * Fix undefined shifts with negative values in certificates parsing
275     (found by Catena cyber using oss-fuzz)
276   * Fix memory leak and free without initialization in pk_encrypt
277     and pk_decrypt example programs. Reported by Brace Stout. Fixes #1128.
278   * Remove redundant else statement. Raised by irwir. Fixes #1776.
279
280Changes
281   * Copy headers preserving timestamps when doing a "make install".
282     Contributed by xueruini.
283   * Allow the forward declaration of public structs. Contributed by Dawid
284     Drozd. Fixes #1215 raised by randombit.
285   * Improve compatibility with some alternative CCM implementations by using
286     CCM test vectors from RAM.
287   * Add support for buffering of out-of-order handshake messages.
288   * Add warnings to the documentation of the HKDF module to reduce the risk
289     of misusing the mbedtls_hkdf_extract() and mbedtls_hkdf_expand()
290     functions. Fixes #1775. Reported by Brian J. Murray.
291
292= mbed TLS 2.12.0 branch released 2018-07-25
293
294Security
295   * Fix a vulnerability in TLS ciphersuites based on CBC and using SHA-384,
296     in (D)TLS 1.0 to 1.2, that allowed an active network attacker to
297     partially recover the plaintext of messages under some conditions by
298     exploiting timing measurements. With DTLS, the attacker could perform
299     this recovery by sending many messages in the same connection. With TLS
300     or if mbedtls_ssl_conf_dtls_badmac_limit() was used, the attack only
301     worked if the same secret (for example a HTTP Cookie) has been repeatedly
302     sent over connections manipulated by the attacker. Connections using GCM
303     or CCM instead of CBC, using hash sizes other than SHA-384, or using
304     Encrypt-then-Mac (RFC 7366) were not affected. The vulnerability was
305     caused by a miscalculation (for SHA-384) in a countermeasure to the
306     original Lucky 13 attack. Found by Kenny Paterson, Eyal Ronen and Adi
307     Shamir.
308   * Fix a vulnerability in TLS ciphersuites based on CBC, in (D)TLS 1.0 to
309     1.2, that allowed a local attacker, able to execute code on the local
310     machine as well as manipulate network packets, to partially recover the
311     plaintext of messages under some conditions by using a cache attack
312     targetting an internal MD/SHA buffer. With TLS or if
313     mbedtls_ssl_conf_dtls_badmac_limit() was used, the attack only worked if
314     the same secret (for example a HTTP Cookie) has been repeatedly sent over
315     connections manipulated by the attacker. Connections using GCM or CCM
316     instead of CBC or using Encrypt-then-Mac (RFC 7366) were not affected.
317     Found by Kenny Paterson, Eyal Ronen and Adi Shamir.
318   * Add a counter-measure against a vulnerability in TLS ciphersuites based
319     on CBC, in (D)TLS 1.0 to 1.2, that allowed a local attacker, able to
320     execute code on the local machine as well as manipulate network packets,
321     to partially recover the plaintext of messages under some conditions (see
322     previous entry) by using a cache attack targeting the SSL input record
323     buffer. Connections using GCM or CCM instead of CBC or using
324     Encrypt-then-Mac (RFC 7366) were not affected. Found by Kenny Paterson,
325     Eyal Ronen and Adi Shamir.
326
327Features
328   * Add new crypto primitives from RFC 7539: stream cipher Chacha20, one-time
329     authenticator Poly1305 and AEAD construct Chacha20-Poly1305. Contributed
330     by Daniel King.
331   * Add support for CHACHA20-POLY1305 ciphersuites from RFC 7905.
332   * Add platform support for the Haiku OS. (https://www.haiku-os.org).
333     Contributed by Augustin Cavalier.
334   * Make the receive and transmit buffers independent sizes, for situations
335     where the outgoing buffer can be fixed at a smaller size than the incoming
336     buffer, which can save some RAM. If buffer lengths are kept equal, there
337     is no functional difference. Contributed by Angus Gratton, and also
338     independently contributed again by Paul Sokolovsky.
339   * Add support for key wrapping modes based on AES as defined by
340     NIST SP 800-38F algorithms KW and KWP and by RFC 3394 and RFC 5649.
341
342Bugfix
343   * Fix the key_app_writer example which was writing a leading zero byte which
344     was creating an invalid ASN.1 tag. Found by Aryeh R. Fixes #1257.
345   * Fix compilation error on C++, because of a variable named new.
346     Found and fixed by Hirotaka Niisato in #1783.
347   * Fix "no symbols" warning issued by ranlib when building on Mac OS X. Fix
348     contributed by tabascoeye.
349   * Clarify documentation for mbedtls_ssl_write() to include 0 as a valid
350     return value. Found by @davidwu2000. #839
351   * Fix a memory leak in mbedtls_x509_csr_parse(), found by catenacyber,
352     Philippe Antoine. Fixes #1623.
353   * Remove unused headers included in x509.c. Found by Chris Hanson and fixed
354     by Brendan Shanks. Part of a fix for #992.
355   * Fix compilation error when MBEDTLS_ARC4_C is disabled and
356     MBEDTLS_CIPHER_NULL_CIPHER is enabled. Found by TrinityTonic in #1719.
357   * Added length checks to some TLS parsing functions. Found and fixed by
358     Philippe Antoine from Catena cyber. #1663.
359   * Fix the inline assembly for the MPI multiply helper function for i386 and
360     i386 with SSE2. Found by László Langó. Fixes #1550
361   * Fix namespacing in header files. Remove the `mbedtls` namespacing in
362     the `#include` in the header files. Resolves #857
363   * Fix compiler warning of 'use before initialisation' in
364     mbedtls_pk_parse_key(). Found by Martin Boye Petersen and fixed by Dawid
365     Drozd. #1098
366   * Fix decryption for zero length messages (which contain all padding) when a
367     CBC based ciphersuite is used together with Encrypt-then-MAC. Previously,
368     such a message was wrongly reported as an invalid record and therefore lead
369     to the connection being terminated. Seen most often with OpenSSL using
370     TLS 1.0. Reported by @kFYatek and by Conor Murphy on the forum. Fix
371     contributed by Espressif Systems. Fixes #1632
372   * Fix ssl_client2 example to send application data with 0-length content
373     when the request_size argument is set to 0 as stated in the documentation.
374     Fixes #1833.
375   * Correct the documentation for `mbedtls_ssl_get_session()`. This API has
376     deep copy of the session, and the peer certificate is not lost. Fixes #926.
377   * Fix build using -std=c99. Fixed by Nick Wilson.
378
379Changes
380   * Fail when receiving a TLS alert message with an invalid length, or invalid
381     zero-length messages when using TLS 1.2. Contributed by Espressif Systems.
382   * Change the default behaviour of mbedtls_hkdf_extract() to return an error
383     when calling with a NULL salt and non-zero salt_len. Contributed by
384     Brian J Murray
385   * Change the shebang line in Perl scripts to look up perl in the PATH.
386     Contributed by fbrosson.
387   * Allow overriding the time on Windows via the platform-time abstraction.
388     Fixed by Nick Wilson.
389   * Use gmtime_r/gmtime_s for thread-safety. Fixed by Nick Wilson.
390
391= mbed TLS 2.11.0 branch released 2018-06-18
392
393Features
394   * Add additional block mode, OFB (Output Feedback), to the AES module and
395     cipher abstraction module.
396   * Implement the HMAC-based extract-and-expand key derivation function
397     (HKDF) per RFC 5869. Contributed by Thomas Fossati.
398   * Add support for the CCM* block cipher mode as defined in IEEE Std. 802.15.4.
399   * Add support for the XTS block cipher mode with AES (AES-XTS).
400     Contributed by Aorimn in pull request #414.
401   * In TLS servers, support offloading private key operations to an external
402     cryptoprocessor. Private key operations can be asynchronous to allow
403     non-blocking operation of the TLS server stack.
404
405Bugfix
406   * Fix the cert_write example to handle certificates signed with elliptic
407     curves as well as RSA. Fixes #777 found by dbedev.
408   * Fix for redefinition of _WIN32_WINNT to avoid overriding a definition
409     used by user applications. Found and fixed by Fabio Alessandrelli.
410   * Fix compilation warnings with IAR toolchain, on 32 bit platform.
411     Reported by rahmanih in #683
412   * Fix braces in mbedtls_memory_buffer_alloc_status(). Found by sbranden, #552.
413
414Changes
415   * Changed CMake defaults for IAR to treat all compiler warnings as errors.
416   * Changed the Clang parameters used in the CMake build files to work for
417     versions later than 3.6. Versions of Clang earlier than this may no longer
418     work. Fixes #1072
419
420= mbed TLS 2.10.0 branch released 2018-06-06
421
422Features
423   * Add support for ARIA cipher (RFC 5794) and associated TLS ciphersuites
424     (RFC 6209). Disabled by default, see MBEDTLS_ARIA_C in config.h
425
426API Changes
427   * Extend the platform module with a util component that contains
428     functionality shared by multiple Mbed TLS modules. At this stage
429     platform_util.h (and its associated platform_util.c) only contain
430     mbedtls_platform_zeroize(), which is a critical function from a security
431     point of view. mbedtls_platform_zeroize() needs to be regularly tested
432     against compilers to ensure that calls to it are not removed from the
433     output binary as part of redundant code elimination optimizations.
434     Therefore, mbedtls_platform_zeroize() is moved to the platform module to
435     facilitate testing and maintenance.
436
437Bugfix
438   * Fix an issue with MicroBlaze support in bn_mul.h which was causing the
439     build to fail. Found by zv-io. Fixes #1651.
440
441Changes
442   * Support TLS testing in out-of-source builds using cmake. Fixes #1193.
443   * Fix redundant declaration of mbedtls_ssl_list_ciphersuites. Raised by
444     TrinityTonic. #1359.
445
446= mbed TLS 2.9.0 branch released 2018-04-30
447
448Security
449   * Fix an issue in the X.509 module which could lead to a buffer overread
450     during certificate validation. Additionally, the issue could also lead to
451     unnecessary callback checks being made or to some validation checks to be
452     omitted. The overread could be triggered remotely, while the other issues
453     would require a non DER-compliant certificate to be correctly signed by a
454     trusted CA, or a trusted CA with a non DER-compliant certificate. Found by
455     luocm. Fixes #825.
456   * Fix the buffer length assertion in the ssl_parse_certificate_request()
457     function which led to an arbitrary overread of the message buffer. The
458     overreads could be caused by receiving a malformed message at the point
459     where an optional signature algorithms list is expected when the signature
460     algorithms section is too short. In builds with debug output, the overread
461     data is output with the debug data.
462   * Fix a client-side bug in the validation of the server's ciphersuite choice
463     which could potentially lead to the client accepting a ciphersuite it didn't
464     offer or a ciphersuite that cannot be used with the TLS or DTLS version
465     chosen by the server. This could lead to corruption of internal data
466     structures for some configurations.
467
468Features
469   * Add an option, MBEDTLS_AES_FEWER_TABLES, to dynamically compute smaller AES
470     tables during runtime, thereby reducing the RAM/ROM footprint by ~6KiB.
471     Suggested and contributed by jkivilin in pull request #394.
472   * Add initial support for Curve448 (RFC 7748). Only mbedtls_ecp_mul() and
473     ECDH primitive functions (mbedtls_ecdh_gen_public(),
474     mbedtls_ecdh_compute_shared()) are supported for now. Contributed by
475     Nicholas Wilson in pull request #348.
476
477API Changes
478   * Extend the public API with the function of mbedtls_net_poll() to allow user
479     applications to wait for a network context to become ready before reading
480     or writing.
481   * Add function mbedtls_ssl_check_pending() to the public API to allow
482     a check for whether more more data is pending to be processed in the
483     internal message buffers.
484     This function is necessary to determine when it is safe to idle on the
485     underlying transport in case event-driven IO is used.
486
487Bugfix
488   * Fix a spurious uninitialized variable warning in cmac.c. Fix independently
489     contributed by Brian J Murray and David Brown.
490   * Add missing dependencies in test suites that led to build failures
491     in configurations that omit certain hashes or public-key algorithms.
492     Fixes #1040.
493   * Fix C89 incompatibility in benchmark.c. Contributed by Brendan Shanks.
494     #1353
495   * Add missing dependencies for MBEDTLS_HAVE_TIME_DATE and
496     MBEDTLS_VERSION_FEATURES in some test suites. Contributed by
497     Deomid Ryabkov. Fixes #1299, #1475.
498   * Fix the Makefile build process for building shared libraries on Mac OS X.
499     Fixed by mnacamura.
500   * Fix parsing of PKCS#8 encoded Elliptic Curve keys. Previously Mbed TLS was
501     unable to parse keys which had only the optional parameters field of the
502     ECPrivateKey structure. Found by Jethro Beekman, fixed in #1379.
503   * Return the plaintext data more quickly on unpadded CBC decryption, as
504     stated in the mbedtls_cipher_update() documentation. Contributed by
505     Andy Leiserson.
506   * Fix overriding and ignoring return values when parsing and writing to
507     a file in pk_sign program. Found by kevlut in #1142.
508   * Restrict usage of error code MBEDTLS_ERR_SSL_WANT_READ to situations
509     where data needs to be fetched from the underlying transport in order
510     to make progress. Previously, this error code was also occasionally
511     returned when unexpected messages were being discarded, ignoring that
512     further messages could potentially already be pending to be processed
513     in the internal buffers; these cases led to deadlocks when event-driven
514     I/O was used. Found and reported by Hubert Mis in #772.
515   * Fix buffer length assertions in the ssl_parse_certificate_request()
516     function which leads to a potential one byte overread of the message
517     buffer.
518   * Fix invalid buffer sizes passed to zlib during record compression and
519     decompression.
520   * Fix the soversion of libmbedcrypto to match the soversion of the
521     maintained 2.7 branch. The soversion was increased in Mbed TLS
522     version 2.7.1 to reflect breaking changes in that release, but the
523     increment was missed in 2.8.0 and later releases outside of the 2.7 branch.
524
525Changes
526   * Remove some redundant code in bignum.c. Contributed by Alexey Skalozub.
527   * Support cmake builds where Mbed TLS is a subproject. Fix contributed
528     independently by Matthieu Volat and Arne Schwabe.
529   * Improve testing in configurations that omit certain hashes or
530     public-key algorithms. Includes contributions by Gert van Dijk.
531   * Improve negative testing of X.509 parsing.
532   * Do not define global mutexes around readdir() and gmtime() in
533     configurations where the feature is disabled. Found and fixed by Gergely
534     Budai.
535   * Harden the function mbedtls_ssl_config_free() against misuse, so that it
536     doesn't leak memory if the user doesn't use mbedtls_ssl_conf_psk() and
537     instead incorrectly manipulates the configuration structure directly.
538     Found and fix submitted by junyeonLEE in #1220.
539   * Provide an empty implementation of mbedtls_pkcs5_pbes2() when
540     MBEDTLS_ASN1_PARSE_C is not enabled. This allows the use of PBKDF2
541     without PBES2. Fixed by Marcos Del Sol Vives.
542   * Add the order of the base point as N in the mbedtls_ecp_group structure
543     for Curve25519 (other curves had it already). Contributed by Nicholas
544     Wilson #481
545   * Improve the documentation of mbedtls_net_accept(). Contributed by Ivan
546     Krylov.
547   * Improve the documentation of mbedtls_ssl_write(). Suggested by
548     Paul Sokolovsky in #1356.
549   * Add an option in the Makefile to support ar utilities where the operation
550     letter must not be prefixed by '-', such as LLVM. Found and fixed by
551     Alex Hixon.
552   * Allow configuring the shared library extension by setting the DLEXT
553     environment variable when using the project makefiles.
554   * Optimize unnecessary zeroing in mbedtls_mpi_copy. Based on a contribution
555     by Alexey Skalozub in #405.
556   * In the SSL module, when f_send, f_recv or f_recv_timeout report
557     transmitting more than the required length, return an error. Raised by
558     Sam O'Connor in #1245.
559   * Improve robustness of mbedtls_ssl_derive_keys against the use of
560     HMAC functions with non-HMAC ciphersuites. Independently contributed
561     by Jiayuan Chen in #1377. Fixes #1437.
562   * Improve security of RSA key generation by including criteria from
563     FIPS 186-4. Contributed by Jethro Beekman. #1380
564   * Declare functions in header files even when an alternative implementation
565     of the corresponding module is activated by defining the corresponding
566     MBEDTLS_XXX_ALT macro. This means that alternative implementations do
567     not need to copy the declarations, and ensures that they will have the
568     same API.
569   * Add platform setup and teardown calls in test suites.
570
571= mbed TLS 2.8.0 branch released 2018-03-16
572
573Default behavior changes
574   * The truncated HMAC extension now conforms to RFC 6066. This means
575     that when both sides of a TLS connection negotiate the truncated
576     HMAC extension, Mbed TLS can now interoperate with other
577     compliant implementations, but this breaks interoperability with
578     prior versions of Mbed TLS. To restore the old behavior, enable
579     the (deprecated) option MBEDTLS_SSL_TRUNCATED_HMAC_COMPAT in
580     config.h. Found by Andreas Walz (ivESK, Offenburg University of
581     Applied Sciences).
582
583Security
584   * Fix implementation of the truncated HMAC extension. The previous
585     implementation allowed an offline 2^80 brute force attack on the
586     HMAC key of a single, uninterrupted connection (with no
587     resumption of the session).
588   * Verify results of RSA private key operations to defend
589     against Bellcore glitch attack.
590   * Fix a buffer overread in ssl_parse_server_key_exchange() that could cause
591     a crash on invalid input.
592   * Fix a buffer overread in ssl_parse_server_psk_hint() that could cause a
593     crash on invalid input.
594   * Fix CRL parsing to reject CRLs containing unsupported critical
595     extensions. Found by Falko Strenzke and Evangelos Karatsiolis.
596
597Features
598   * Extend PKCS#8 interface by introducing support for the entire SHA
599     algorithms family when encrypting private keys using PKCS#5 v2.0.
600     This allows reading encrypted PEM files produced by software that
601     uses PBKDF2-SHA2, such as OpenSSL 1.1. Submitted by Antonio Quartulli,
602     OpenVPN Inc. Fixes #1339
603   * Add support for public keys encoded in PKCS#1 format. #1122
604
605New deprecations
606   * Deprecate support for record compression (configuration option
607     MBEDTLS_ZLIB_SUPPORT).
608
609Bugfix
610   * Fix the name of a DHE parameter that was accidentally changed in 2.7.0.
611     Fixes #1358.
612   * Fix test_suite_pk to work on 64-bit ILP32 systems. #849
613   * Fix mbedtls_x509_crt_profile_suiteb, which used to reject all certificates
614     with flag MBEDTLS_X509_BADCERT_BAD_PK even when the key type was correct.
615     In the context of SSL, this resulted in handshake failure. Reported by
616     daniel in the Mbed TLS forum. #1351
617   * Fix Windows x64 builds with the included mbedTLS.sln file. #1347
618   * Fix setting version TLSv1 as minimal version, even if TLS 1
619     is not enabled. Set MBEDTLS_SSL_MIN_MAJOR_VERSION
620     and MBEDTLS_SSL_MIN_MINOR_VERSION instead of
621     MBEDTLS_SSL_MAJOR_VERSION_3 and MBEDTLS_SSL_MINOR_VERSION_1. #664
622   * Fix compilation error on Mingw32 when _TRUNCATE is defined. Use _TRUNCATE
623     only if __MINGW32__ not defined. Fix suggested by Thomas Glanzmann and
624     Nick Wilson on issue #355
625   * In test_suite_pk, pass valid parameters when testing for hash length
626     overflow. #1179
627   * Fix memory allocation corner cases in memory_buffer_alloc.c module. Found
628     by Guido Vranken. #639
629   * Log correct number of ciphersuites used in Client Hello message. #918
630   * Fix X509 CRT parsing that would potentially accept an invalid tag when
631     parsing the subject alternative names.
632   * Fix a possible arithmetic overflow in ssl_parse_server_key_exchange()
633     that could cause a key exchange to fail on valid data.
634   * Fix a possible arithmetic overflow in ssl_parse_server_psk_hint() that
635     could cause a key exchange to fail on valid data.
636   * Don't define mbedtls_aes_decrypt and mbedtls_aes_encrypt under
637     MBEDTLS_DEPRECATED_REMOVED. #1388
638   * Fix a 1-byte heap buffer overflow (read-only) during private key parsing.
639     Found through fuzz testing.
640
641Changes
642   * Fix tag lengths and value ranges in the documentation of CCM encryption.
643     Contributed by Mathieu Briand.
644   * Fix typo in a comment ctr_drbg.c. Contributed by Paul Sokolovsky.
645   * Remove support for the library reference configuration for picocoin.
646   * MD functions deprecated in 2.7.0 are no longer inline, to provide
647     a migration path for those depending on the library's ABI.
648   * Clarify the documentation of mbedtls_ssl_setup.
649   * Use (void) when defining functions with no parameters. Contributed by
650     Joris Aerts. #678
651
652= mbed TLS 2.7.0 branch released 2018-02-03
653
654Security
655   * Fix a heap corruption issue in the implementation of the truncated HMAC
656     extension. When the truncated HMAC extension is enabled and CBC is used,
657     sending a malicious application packet could be used to selectively corrupt
658     6 bytes on the peer's heap, which could potentially lead to crash or remote
659     code execution. The issue could be triggered remotely from either side in
660     both TLS and DTLS. CVE-2018-0488
661   * Fix a buffer overflow in RSA-PSS verification when the hash was too large
662     for the key size, which could potentially lead to crash or remote code
663     execution. Found by Seth Terashima, Qualcomm Product Security Initiative,
664     Qualcomm Technologies Inc. CVE-2018-0487
665   * Fix buffer overflow in RSA-PSS verification when the unmasked data is all
666     zeros.
667   * Fix an unsafe bounds check in ssl_parse_client_psk_identity() when adding
668     64 KiB to the address of the SSL buffer and causing a wrap around.
669   * Fix a potential heap buffer overflow in mbedtls_ssl_write(). When the (by
670     default enabled) maximum fragment length extension is disabled in the
671     config and the application data buffer passed to mbedtls_ssl_write
672     is larger than the internal message buffer (16384 bytes by default), the
673     latter overflows. The exploitability of this issue depends on whether the
674     application layer can be forced into sending such large packets. The issue
675     was independently reported by Tim Nordell via e-mail and by Florin Petriuc
676     and sjorsdewit on GitHub. Fix proposed by Florin Petriuc in #1022.
677     Fixes #707.
678   * Add a provision to prevent compiler optimizations breaking the time
679     constancy of mbedtls_ssl_safer_memcmp().
680   * Ensure that buffers are cleared after use if they contain sensitive data.
681     Changes were introduced in multiple places in the library.
682   * Set PEM buffer to zero before freeing it, to avoid decoded private keys
683     being leaked to memory after release.
684   * Fix dhm_check_range() failing to detect trivial subgroups and potentially
685     leaking 1 bit of the private key. Reported by prashantkspatil.
686   * Make mbedtls_mpi_read_binary() constant-time with respect to the input
687     data. Previously, trailing zero bytes were detected and omitted for the
688     sake of saving memory, but potentially leading to slight timing
689     differences. Reported by Marco Macchetti, Kudelski Group.
690   * Wipe stack buffer temporarily holding EC private exponent
691     after keypair generation.
692   * Fix a potential heap buffer over-read in ALPN extension parsing
693     (server-side). Could result in application crash, but only if an ALPN
694     name larger than 16 bytes had been configured on the server.
695   * Change default choice of DHE parameters from untrustworthy RFC 5114
696     to RFC 3526 containing parameters generated in a nothing-up-my-sleeve
697     manner.
698
699Features
700   * Allow comments in test data files.
701   * The selftest program can execute a subset of the tests based on command
702     line arguments.
703   * New unit tests for timing. Improve the self-test to be more robust
704     when run on a heavily-loaded machine.
705   * Add alternative implementation support for CCM and CMAC (MBEDTLS_CCM_ALT,
706     MBEDTLS_CMAC_ALT). Submitted by Steven Cooreman, Silicon Labs.
707   * Add support for alternative implementations of GCM, selected by the
708     configuration flag MBEDTLS_GCM_ALT.
709   * Add support for alternative implementations for ECDSA, controlled by new
710     configuration flags MBEDTLS_ECDSA_SIGN_ALT, MBEDTLS_ECDSA_VERIFY_ALT and
711     MBEDTLS_ECDSDA_GENKEY_AT in config.h.
712     The following functions from the ECDSA module can be replaced
713     with alternative implementation:
714     mbedtls_ecdsa_sign(), mbedtls_ecdsa_verify() and mbedtls_ecdsa_genkey().
715   * Add support for alternative implementation of ECDH, controlled by the
716     new configuration flags MBEDTLS_ECDH_COMPUTE_SHARED_ALT and
717     MBEDTLS_ECDH_GEN_PUBLIC_ALT in config.h.
718     The following functions from the ECDH module can be replaced
719     with an alternative implementation:
720     mbedtls_ecdh_gen_public() and mbedtls_ecdh_compute_shared().
721   * Add support for alternative implementation of ECJPAKE, controlled by
722     the new configuration flag MBEDTLS_ECJPAKE_ALT.
723   * Add mechanism to provide alternative implementation of the DHM module.
724
725API Changes
726   * Extend RSA interface by multiple functions allowing structure-
727     independent setup and export of RSA contexts. Most notably,
728     mbedtls_rsa_import() and mbedtls_rsa_complete() are introduced for setting
729     up RSA contexts from partial key material and having them completed to the
730     needs of the implementation automatically. This allows to setup private RSA
731     contexts from keys consisting of N,D,E only, even if P,Q are needed for the
732     purpose or CRT and/or blinding.
733   * The configuration option MBEDTLS_RSA_ALT can be used to define alternative
734     implementations of the RSA interface declared in rsa.h.
735   * The following functions in the message digest modules (MD2, MD4, MD5,
736     SHA1, SHA256, SHA512) have been deprecated and replaced as shown below.
737     The new functions change the return type from void to int to allow
738     returning error codes when using MBEDTLS_<MODULE>_ALT.
739     mbedtls_<MODULE>_starts() -> mbedtls_<MODULE>_starts_ret()
740     mbedtls_<MODULE>_update() -> mbedtls_<MODULE>_update_ret()
741     mbedtls_<MODULE>_finish() -> mbedtls_<MODULE>_finish_ret()
742     mbedtls_<MODULE>_process() -> mbedtls_internal_<MODULE>_process()
743
744New deprecations
745   * Deprecate usage of RSA primitives with non-matching key-type
746     (e.g. signing with a public key).
747   * Direct manipulation of structure fields of RSA contexts is deprecated.
748     Users are advised to use the extended RSA API instead.
749   * Deprecate usage of message digest functions that return void
750     (mbedtls_<MODULE>_starts, mbedtls_<MODULE>_update,
751     mbedtls_<MODULE>_finish and mbedtls_<MODULE>_process where <MODULE> is
752     any of MD2, MD4, MD5, SHA1, SHA256, SHA512) in favor of functions
753     that can return an error code.
754   * Deprecate untrustworthy DHE parameters from RFC 5114. Superseded by
755     parameters from RFC 3526 or the newly added parameters from RFC 7919.
756   * Deprecate hex string DHE constants MBEDTLS_DHM_RFC3526_MODP_2048_P etc.
757     Supserseded by binary encoded constants MBEDTLS_DHM_RFC3526_MODP_2048_P_BIN
758     etc.
759   * Deprecate mbedtls_ssl_conf_dh_param() for setting default DHE parameters
760     from hex strings. Superseded by mbedtls_ssl_conf_dh_param_bin()
761     accepting DHM parameters in binary form, matching the new constants.
762
763Bugfix
764   * Fix ssl_parse_record_header() to silently discard invalid DTLS records
765     as recommended in RFC 6347 Section 4.1.2.7.
766   * Fix memory leak in mbedtls_ssl_set_hostname() when called multiple times.
767     Found by projectgus and Jethro Beekman, #836.
768   * Fix usage help in ssl_server2 example. Found and fixed by Bei Lin.
769   * Parse signature algorithm extension when renegotiating. Previously,
770     renegotiated handshakes would only accept signatures using SHA-1
771     regardless of the peer's preferences, or fail if SHA-1 was disabled.
772   * Fix leap year calculation in x509_date_is_valid() to ensure that invalid
773     dates on leap years with 100 and 400 intervals are handled correctly. Found
774     by Nicholas Wilson. #694
775   * Fix some invalid RSA-PSS signatures with keys of size 8N+1 that were
776     accepted. Generating these signatures required the private key.
777   * Fix out-of-memory problem when parsing 4096-bit PKCS8-encrypted RSA keys.
778     Found independently by Florian in the mbed TLS forum and by Mishamax.
779     #878, #1019.
780   * Fix variable used before assignment compilation warnings with IAR
781     toolchain. Found by gkerrien38.
782   * Fix unchecked return codes from AES, DES and 3DES functions in
783     pem_aes_decrypt(), pem_des_decrypt() and pem_des3_decrypt() respectively.
784     If a call to one of the functions of the cryptographic primitive modules
785     failed, the error may not be noticed by the function
786     mbedtls_pem_read_buffer() causing it to return invalid values. Found by
787     Guido Vranken. #756
788   * Include configuration file in md.h, to fix compilation warnings.
789     Reported by aaronmdjones in #1001
790   * Correct extraction of signature-type from PK instance in X.509 CRT and CSR
791     writing routines that prevented these functions to work with alternative
792     RSA implementations. Raised by J.B. in the Mbed TLS forum. Fixes #1011.
793   * Don't print X.509 version tag for v1 CRT's, and omit extensions for
794     non-v3 CRT's.
795   * Fix bugs in RSA test suite under MBEDTLS_NO_PLATFORM_ENTROPY. #1023 #1024
796   * Fix net_would_block() to avoid modification by errno through fcntl() call.
797     Found by nkolban. Fixes #845.
798   * Fix handling of handshake messages in mbedtls_ssl_read() in case
799     MBEDTLS_SSL_RENEGOTIATION is disabled. Found by erja-gp.
800   * Add a check for invalid private parameters in mbedtls_ecdsa_sign().
801     Reported by Yolan Romailler.
802   * Fix word size check in in pk.c to not depend on MBEDTLS_HAVE_INT64.
803   * Fix incorrect unit in benchmark output. #850
804   * Add size-checks for record and handshake message content, securing
805     fragile yet non-exploitable code-paths.
806   * Fix crash when calling mbedtls_ssl_cache_free() twice. Found by
807     MilenkoMitrovic, #1104
808   * Fix mbedtls_timing_alarm(0) on Unix and MinGW.
809   * Fix use of uninitialized memory in mbedtls_timing_get_timer() when reset=1.
810   * Fix possible memory leaks in mbedtls_gcm_self_test().
811   * Added missing return code checks in mbedtls_aes_self_test().
812   * Fix issues in RSA key generation program programs/x509/rsa_genkey and the
813     RSA test suite where the failure of CTR DRBG initialization lead to
814     freeing an RSA context and several MPI's without proper initialization
815     beforehand.
816   * Fix error message in programs/pkey/gen_key.c. Found and fixed by Chris Xue.
817   * Fix programs/pkey/dh_server.c so that it actually works with dh_client.c.
818     Found and fixed by Martijn de Milliano.
819   * Fix an issue in the cipher decryption with the mode
820     MBEDTLS_PADDING_ONE_AND_ZEROS that sometimes accepted invalid padding.
821     Note, this padding mode is not used by the TLS protocol. Found and fixed by
822     Micha Kraus.
823   * Fix the entropy.c module to not call mbedtls_sha256_starts() or
824     mbedtls_sha512_starts() in the mbedtls_entropy_init() function.
825   * Fix the entropy.c module to ensure that mbedtls_sha256_init() or
826     mbedtls_sha512_init() is called before operating on the relevant context
827     structure. Do not assume that zeroizing a context is a correct way to
828     reset it. Found independently by ccli8 on Github.
829   * In mbedtls_entropy_free(), properly free the message digest context.
830   * Fix status handshake status message in programs/ssl/dtls_client.c. Found
831     and fixed by muddog.
832
833Changes
834   * Extend cert_write example program by options to set the certificate version
835     and the message digest. Further, allow enabling/disabling of authority
836     identifier, subject identifier and basic constraints extensions.
837   * Only check for necessary RSA structure fields in `mbedtls_rsa_private`. In
838     particular, don't require P,Q if neither CRT nor blinding are
839     used. Reported and fix proposed independently by satur9nine and sliai
840     on GitHub.
841   * Only run AES-192 self-test if AES-192 is available. Fixes #963.
842   * Tighten the RSA PKCS#1 v1.5 signature verification code and remove the
843     undeclared dependency of the RSA module on the ASN.1 module.
844   * Update all internal usage of deprecated message digest functions to the
845     new ones with return codes. In particular, this modifies the
846     mbedtls_md_info_t structure. Propagate errors from these functions
847     everywhere except some locations in the ssl_tls.c module.
848   * Improve CTR_DRBG error handling by propagating underlying AES errors.
849   * Add MBEDTLS_ERR_XXX_HW_ACCEL_FAILED error codes for all cryptography
850     modules where the software implementation can be replaced by a hardware
851     implementation.
852   * Add explicit warnings for the use of MD2, MD4, MD5, SHA-1, DES and ARC4
853     throughout the library.
854
855= mbed TLS 2.6.0 branch released 2017-08-10
856
857Security
858   * Fix authentication bypass in SSL/TLS: when authmode is set to optional,
859     mbedtls_ssl_get_verify_result() would incorrectly return 0 when the peer's
860     X.509 certificate chain had more than MBEDTLS_X509_MAX_INTERMEDIATE_CA
861     (default: 8) intermediates, even when it was not trusted. This could be
862     triggered remotely from either side. (With authmode set to 'required'
863     (the default), the handshake was correctly aborted).
864   * Reliably wipe sensitive data after use in the AES example applications
865     programs/aes/aescrypt2 and programs/aes/crypt_and_hash.
866     Found by Laurent Simon.
867
868Features
869   * Add the functions mbedtls_platform_setup() and mbedtls_platform_teardown()
870     and the context struct mbedtls_platform_context to perform
871     platform-specific setup and teardown operations. The macro
872     MBEDTLS_PLATFORM_SETUP_TEARDOWN_ALT allows the functions to be overridden
873     by the user in a platform_alt.h file. These new functions are required in
874     some embedded environments to provide a means of initialising underlying
875     cryptographic acceleration hardware.
876
877API Changes
878   * Reverted API/ABI breaking changes introduced in mbed TLS 2.5.1, to make the
879     API consistent with mbed TLS 2.5.0. Specifically removed the inline
880     qualifier from the functions mbedtls_aes_decrypt, mbedtls_aes_encrypt,
881     mbedtls_ssl_ciphersuite_uses_ec and mbedtls_ssl_ciphersuite_uses_psk. Found
882     by James Cowgill. #978
883   * Certificate verification functions now set flags to -1 in case the full
884     chain was not verified due to an internal error (including in the verify
885     callback) or chain length limitations.
886   * With authmode set to optional, the TLS handshake is now aborted if the
887     verification of the peer's certificate failed due to an overlong chain or
888     a fatal error in the verify callback.
889
890Bugfix
891   * Add a check if iv_len is zero in GCM, and return an error if it is zero.
892     Reported by roberto. #716
893   * Replace preprocessor condition from #if defined(MBEDTLS_THREADING_PTHREAD)
894     to #if defined(MBEDTLS_THREADING_C) as the library cannot assume they will
895     always be implemented by pthread support. #696
896   * Fix a resource leak on Windows platforms in mbedtls_x509_crt_parse_path(),
897     in the case of an error. Found by redplait. #590
898   * Add MBEDTLS_MPI_CHK to check for error value of mbedtls_mpi_fill_random.
899     Reported and fix suggested by guidovranken. #740
900   * Fix conditional preprocessor directives in bignum.h to enable 64-bit
901     compilation when using ARM Compiler 6.
902   * Fix a potential integer overflow in the version verification for DER
903     encoded X.509 CRLs. The overflow could enable maliciously constructed CRLs
904     to bypass the version verification check. Found by Peng Li/Yueh-Hsun Lin,
905     KNOX Security, Samsung Research America
906   * Fix potential integer overflow in the version verification for DER
907     encoded X.509 CSRs. The overflow could enable maliciously constructed CSRs
908     to bypass the version verification check. Found by Peng Li/Yueh-Hsun Lin,
909     KNOX Security, Samsung Research America
910   * Fix a potential integer overflow in the version verification for DER
911     encoded X.509 certificates. The overflow could enable maliciously
912     constructed certificates to bypass the certificate verification check.
913   * Fix a call to the libc function time() to call the platform abstraction
914     function mbedtls_time() instead. Found by wairua. #666
915   * Avoid shadowing of time and index functions through mbed TLS function
916     arguments. Found by inestlerode. #557.
917
918Changes
919   * Added config.h option MBEDTLS_NO_UDBL_DIVISION, to prevent the use of
920     64-bit division. This is useful on embedded platforms where 64-bit division
921     created a dependency on external libraries. #708
922   * Removed mutexes from ECP hardware accelerator code. Now all hardware
923     accelerator code in the library leaves concurrency handling to the
924     platform. Reported by Steven Cooreman. #863
925   * Define the macro MBEDTLS_AES_ROM_TABLES in the configuration file
926     config-no-entropy.h to reduce the RAM footprint.
927   * Added a test script that can be hooked into git that verifies commits
928     before they are pushed.
929   * Improve documentation of PKCS1 decryption functions.
930
931= mbed TLS 2.5.1 released 2017-06-21
932
933Security
934   * Fixed unlimited overread of heap-based buffer in mbedtls_ssl_read().
935     The issue could only happen client-side with renegotiation enabled.
936     Could result in DoS (application crash) or information leak
937     (if the application layer sent data read from mbedtls_ssl_read()
938     back to the server or to a third party). Can be triggered remotely.
939   * Removed SHA-1 and RIPEMD-160 from the default hash algorithms for
940     certificate verification. SHA-1 can be turned back on with a compile-time
941     option if needed.
942   * Fixed offset in FALLBACK_SCSV parsing that caused TLS server to fail to
943     detect it sometimes. Reported by Hugo Leisink. #810
944   * Tighten parsing of RSA PKCS#1 v1.5 signatures, to avoid a
945     potential Bleichenbacher/BERserk-style attack.
946
947Bugfix
948   * Remove size zero arrays from ECJPAKE test suite. Size zero arrays are not
949     valid C and they prevented the test from compiling in Visual Studio 2015
950     and with GCC using the -Wpedantic compilation option.
951   * Fix insufficient support for signature-hash-algorithm extension,
952     resulting in compatibility problems with Chrome. Found by hfloyrd. #823
953   * Fix behaviour that hid the original cause of fatal alerts in some cases
954     when sending the alert failed. The fix makes sure not to hide the error
955     that triggered the alert.
956   * Fix SSLv3 renegotiation behaviour and stop processing data received from
957     peer after sending a fatal alert to refuse a renegotiation attempt.
958     Previous behaviour was to keep processing data even after the alert has
959     been sent.
960   * Accept empty trusted CA chain in authentication mode
961     MBEDTLS_SSL_VERIFY_OPTIONAL. Found by Jethro Beekman. #864
962   * Fix implementation of mbedtls_ssl_parse_certificate() to not annihilate
963     fatal errors in authentication mode MBEDTLS_SSL_VERIFY_OPTIONAL and to
964     reflect bad EC curves within verification result.
965   * Fix bug that caused the modular inversion function to accept the invalid
966     modulus 1 and therefore to hang. Found by blaufish. #641.
967   * Fix incorrect sign computation in modular exponentiation when the base is
968     a negative MPI. Previously the result was always negative. Found by Guido
969     Vranken.
970   * Fix a numerical underflow leading to stack overflow in mpi_read_file()
971     that was triggered uppon reading an empty line. Found by Guido Vranken.
972
973Changes
974   * Send fatal alerts in more cases. The previous behaviour was to skip
975     sending the fatal alert and just drop the connection.
976   * Clarify ECDSA documentation and improve the sample code to avoid
977     misunderstanding and potentially dangerous use of the API. Pointed out
978     by Jean-Philippe Aumasson.
979
980= mbed TLS 2.5.0 branch released 2017-05-17
981
982Security
983   * Wipe stack buffers in RSA private key operations
984     (rsa_rsaes_pkcs1_v15_decrypt(), rsa_rsaes_oaep_decrypt). Found by Laurent
985     Simon.
986   * Add exponent blinding to RSA private operations as a countermeasure
987     against side-channel attacks like the cache attack described in
988     https://arxiv.org/abs/1702.08719v2.
989     Found and fix proposed by Michael Schwarz, Samuel Weiser, Daniel Gruss,
990     Clémentine Maurice and Stefan Mangard.
991
992Features
993   * Add hardware acceleration support for the Elliptic Curve Point module.
994     This involved exposing parts of the internal interface to enable
995     replacing the core functions and adding and alternative, module level
996     replacement support for enabling the extension of the interface.
997   * Add a new configuration option to 'mbedtls_ssl_config' to enable
998     suppressing the CA list in Certificate Request messages. The default
999     behaviour has not changed, namely every configured CAs name is included.
1000
1001API Changes
1002   * The following functions in the AES module have been deprecated and replaced
1003     by the functions shown below. The new functions change the return type from
1004     void to int to allow returning error codes when using MBEDTLS_AES_ALT,
1005     MBEDTLS_AES_DECRYPT_ALT or MBEDTLS_AES_ENCRYPT_ALT.
1006     mbedtls_aes_decrypt() -> mbedtls_internal_aes_decrypt()
1007     mbedtls_aes_encrypt() -> mbedtls_internal_aes_encrypt()
1008
1009Bugfix
1010   * Remove macros from compat-1.3.h that correspond to deleted items from most
1011     recent versions of the library. Found by Kyle Keen.
1012   * Fixed issue in the Threading module that prevented mutexes from
1013     initialising. Found by sznaider. #667 #843
1014   * Add checks in the PK module for the RSA functions on 64-bit systems.
1015     The PK and RSA modules use different types for passing hash length and
1016     without these checks the type cast could lead to data loss. Found by Guido
1017     Vranken.
1018
1019= mbed TLS 2.4.2 branch released 2017-03-08
1020
1021Security
1022   * Add checks to prevent signature forgeries for very large messages while
1023     using RSA through the PK module in 64-bit systems. The issue was caused by
1024     some data loss when casting a size_t to an unsigned int value in the
1025     functions rsa_verify_wrap(), rsa_sign_wrap(), rsa_alt_sign_wrap() and
1026     mbedtls_pk_sign(). Found by Jean-Philippe Aumasson.
1027   * Fixed potential livelock during the parsing of a CRL in PEM format in
1028     mbedtls_x509_crl_parse(). A string containing a CRL followed by trailing
1029     characters after the footer could result in the execution of an infinite
1030     loop. The issue can be triggered remotely. Found by Greg Zaverucha,
1031     Microsoft.
1032   * Removed MD5 from the allowed hash algorithms for CertificateRequest and
1033     CertificateVerify messages, to prevent SLOTH attacks against TLS 1.2.
1034     Introduced by interoperability fix for #513.
1035   * Fixed a bug that caused freeing a buffer that was allocated on the stack,
1036     when verifying the validity of a key on secp224k1. This could be
1037     triggered remotely for example with a maliciously constructed certificate
1038     and potentially could lead to remote code execution on some platforms.
1039     Reported independently by rongsaws and Aleksandar Nikolic, Cisco Talos
1040     team. #569 CVE-2017-2784
1041
1042Bugfix
1043   * Fix output certificate verification flags set by x509_crt_verify_top() when
1044     traversing a chain of trusted CA. The issue would cause both flags,
1045     MBEDTLS_X509_BADCERT_NOT_TRUSTED and MBEDTLS_X509_BADCERT_EXPIRED, to be
1046     set when the verification conditions are not met regardless of the cause.
1047     Found by Harm Verhagen and inestlerode. #665 #561
1048   * Fix the redefinition of macro ssl_set_bio to an undefined symbol
1049     mbedtls_ssl_set_bio_timeout in compat-1.3.h, by removing it.
1050     Found by omlib-lin. #673
1051   * Fix unused variable/function compilation warnings in pem.c, x509_crt.c and
1052     x509_csr.c that are reported when building mbed TLS with a config.h that
1053     does not define MBEDTLS_PEM_PARSE_C. Found by omnium21. #562
1054   * Fix incorrect renegotiation condition in ssl_check_ctr_renegotiate() that
1055     would compare 64 bits of the record counter instead of 48 bits as indicated
1056     in RFC 6347 Section 4.3.1. This could cause the execution of the
1057     renegotiation routines at unexpected times when the protocol is DTLS. Found
1058     by wariua. #687
1059   * Fixed multiple buffer overreads in mbedtls_pem_read_buffer() when parsing
1060     the input string in PEM format to extract the different components. Found
1061     by Eyal Itkin.
1062   * Fixed potential arithmetic overflow in mbedtls_ctr_drbg_reseed() that could
1063     cause buffer bound checks to be bypassed. Found by Eyal Itkin.
1064   * Fixed potential arithmetic overflows in mbedtls_cipher_update() that could
1065     cause buffer bound checks to be bypassed. Found by Eyal Itkin.
1066   * Fixed potential arithmetic overflow in mbedtls_md2_update() that could
1067     cause buffer bound checks to be bypassed. Found by Eyal Itkin.
1068   * Fixed potential arithmetic overflow in mbedtls_base64_decode() that could
1069     cause buffer bound checks to be bypassed. Found by Eyal Itkin.
1070   * Fixed heap overreads in mbedtls_x509_get_time(). Found by Peng
1071     Li/Yueh-Hsun Lin, KNOX Security, Samsung Research America.
1072   * Fix potential memory leak in mbedtls_x509_crl_parse(). The leak was caused
1073     by missing calls to mbedtls_pem_free() in cases when a
1074     MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT error was encountered. Found and
1075     fix proposed by Guido Vranken. #722
1076   * Fixed the templates used to generate project and solution files for Visual
1077     Studio 2015 as well as the files themselves, to remove a build warning
1078     generated in Visual Studio 2015. Reported by Steve Valliere. #742
1079   * Fix a resource leak in ssl_cookie, when using MBEDTLS_THREADING_C.
1080     Raised and fix suggested by Alan Gillingham in the mbed TLS forum. #771
1081   * Fix 1 byte buffer overflow in mbedtls_mpi_write_string() when the MPI
1082     number to write in hexadecimal is negative and requires an odd number of
1083     digits. Found and fixed by Guido Vranken.
1084   * Fix unlisted DES configuration dependency in some pkparse test cases. Found
1085     by inestlerode. #555
1086
1087= mbed TLS 2.4.1 branch released 2016-12-13
1088
1089Changes
1090   * Update to CMAC test data, taken from - NIST Special Publication 800-38B -
1091     Recommendation for Block Cipher Modes of Operation: The CMAC Mode for
1092     Authentication – October  2016
1093
1094= mbed TLS 2.4.0 branch released 2016-10-17
1095
1096Security
1097   * Removed the MBEDTLS_SSL_AEAD_RANDOM_IV option, because it was not compliant
1098     with RFC-5116 and could lead to session key recovery in very long TLS
1099     sessions. "Nonce-Disrespecting Adversaries Practical Forgery Attacks on GCM in
1100     TLS" - H. Bock, A. Zauner, S. Devlin, J. Somorovsky, P. Jovanovic.
1101     https://eprint.iacr.org/2016/475.pdf
1102   * Fixed potential stack corruption in mbedtls_x509write_crt_der() and
1103     mbedtls_x509write_csr_der() when the signature is copied to the buffer
1104     without checking whether there is enough space in the destination. The
1105     issue cannot be triggered remotely. Found by Jethro Beekman.
1106
1107Features
1108   * Added support for CMAC for AES and 3DES and AES-CMAC-PRF-128, as defined by
1109     NIST SP 800-38B, RFC-4493 and RFC-4615.
1110   * Added hardware entropy selftest to verify that the hardware entropy source
1111     is functioning correctly.
1112   * Added a script to print build environment info for diagnostic use in test
1113     scripts, which is also now called by all.sh.
1114   * Added the macro MBEDTLS_X509_MAX_FILE_PATH_LEN that enables the user to
1115     configure the maximum length of a file path that can be buffered when
1116     calling mbedtls_x509_crt_parse_path().
1117   * Added a configuration file config-no-entropy.h that configures the subset of
1118     library features that do not require an entropy source.
1119   * Added the macro MBEDTLS_ENTROPY_MIN_HARDWARE in config.h. This allows users
1120     to configure the minimum number of bytes for entropy sources using the
1121     mbedtls_hardware_poll() function.
1122
1123Bugfix
1124   * Fix for platform time abstraction to avoid dependency issues where a build
1125     may need time but not the standard C library abstraction, and added
1126     configuration consistency checks to check_config.h
1127   * Fix dependency issue in Makefile to allow parallel builds.
1128   * Fix incorrect handling of block lengths in crypt_and_hash.c sample program,
1129     when GCM is used. Found by udf2457. #441
1130   * Fix for key exchanges based on ECDH-RSA or ECDH-ECDSA which weren't
1131     enabled unless others were also present. Found by David Fernandez. #428
1132   * Fix for out-of-tree builds using CMake. Found by jwurzer, and fix based on
1133     a contribution from Tobias Tangemann. #541
1134   * Fixed cert_app.c sample program for debug output and for use when no root
1135     certificates are provided.
1136   * Fix conditional statement that would cause a 1 byte overread in
1137     mbedtls_asn1_get_int(). Found and fixed by Guido Vranken. #599
1138   * Fixed pthread implementation to avoid unintended double initialisations
1139     and double frees. Found by Niklas Amnebratt.
1140   * Fixed the sample applications gen_key.c, cert_req.c and cert_write.c for
1141     builds where the configuration MBEDTLS_PEM_WRITE_C is not defined. Found
1142     by inestlerode. #559.
1143   * Fix mbedtls_x509_get_sig() to update the ASN1 type in the mbedtls_x509_buf
1144     data structure until after error checks are successful. Found by
1145     subramanyam-c. #622
1146   * Fix documentation and implementation missmatch for function arguments of
1147     mbedtls_gcm_finish(). Found by cmiatpaar. #602
1148   * Guarantee that P>Q at RSA key generation. Found by inestlerode. #558
1149   * Fix potential byte overread when verifying malformed SERVER_HELLO in
1150     ssl_parse_hello_verify_request() for DTLS. Found by Guido Vranken.
1151   * Fix check for validity of date when parsing in mbedtls_x509_get_time().
1152     Found by subramanyam-c. #626
1153   * Fix compatibility issue with Internet Explorer client authentication,
1154     where the limited hash choices prevented the client from sending its
1155     certificate. Found by teumas. #513
1156   * Fix compilation without MBEDTLS_SELF_TEST enabled.
1157
1158Changes
1159   * Extended test coverage of special cases, and added new timing test suite.
1160   * Removed self-tests from the basic-built-test.sh script, and added all
1161     missing self-tests to the test suites, to ensure self-tests are only
1162     executed once.
1163   * Added support for 3 and 4 byte lengths to mbedtls_asn1_write_len().
1164   * Added support for a Yotta specific configuration file -
1165     through the symbol YOTTA_CFG_MBEDTLS_TARGET_CONFIG_FILE.
1166   * Added optimization for code space for X.509/OID based on configured
1167     features. Contributed by Aviv Palivoda.
1168   * Renamed source file library/net.c to library/net_sockets.c to avoid
1169     naming collision in projects which also have files with the common name
1170     net.c. For consistency, the corresponding header file, net.h, is marked as
1171     deprecated, and its contents moved to net_sockets.h.
1172   * Changed the strategy for X.509 certificate parsing and validation, to no
1173     longer disregard certificates with unrecognised fields.
1174
1175= mbed TLS 2.3.0 branch released 2016-06-28
1176
1177Security
1178   * Fix missing padding length check in mbedtls_rsa_rsaes_pkcs1_v15_decrypt
1179     required by PKCS1 v2.2
1180   * Fix potential integer overflow to buffer overflow in
1181     mbedtls_rsa_rsaes_pkcs1_v15_encrypt and mbedtls_rsa_rsaes_oaep_encrypt
1182     (not triggerable remotely in (D)TLS).
1183   * Fix a potential integer underflow to buffer overread in
1184     mbedtls_rsa_rsaes_oaep_decrypt. It is not triggerable remotely in
1185     SSL/TLS.
1186
1187Features
1188   * Support for platform abstraction of the standard C library time()
1189     function.
1190
1191Bugfix
1192   * Fix bug in mbedtls_mpi_add_mpi() that caused wrong results when the three
1193     arguments where the same (in-place doubling). Found and fixed by Janos
1194     Follath. #309
1195   * Fix potential build failures related to the 'apidoc' target, introduced
1196     in the previous patch release. Found by Robert Scheck. #390 #391
1197   * Fix issue in Makefile that prevented building using armar. #386
1198   * Fix memory leak that occured only when ECJPAKE was enabled and ECDHE and
1199     ECDSA was disabled in config.h . The leak didn't occur by default.
1200   * Fix an issue that caused valid certificates to be rejected whenever an
1201     expired or not yet valid certificate was parsed before a valid certificate
1202     in the trusted certificate list.
1203   * Fix bug in mbedtls_x509_crt_parse that caused trailing extra data in the
1204     buffer after DER certificates to be included in the raw representation.
1205   * Fix issue that caused a hang when generating RSA keys of odd bitlength
1206   * Fix bug in mbedtls_rsa_rsaes_pkcs1_v15_encrypt that made null pointer
1207     dereference possible.
1208   * Fix issue that caused a crash if invalid curves were passed to
1209     mbedtls_ssl_conf_curves. #373
1210   * Fix issue in ssl_fork_server which was preventing it from functioning. #429
1211   * Fix memory leaks in test framework
1212   * Fix test in ssl-opt.sh that does not run properly with valgrind
1213   * Fix unchecked calls to mmbedtls_md_setup(). Fix by Brian Murray. #502
1214
1215Changes
1216   * On ARM platforms, when compiling with -O0 with GCC, Clang or armcc5,
1217     don't use the optimized assembly for bignum multiplication. This removes
1218     the need to pass -fomit-frame-pointer to avoid a build error with -O0.
1219   * Disabled SSLv3 in the default configuration.
1220   * Optimized mbedtls_mpi_zeroize() for MPI integer size. (Fix by Alexey
1221     Skalozub).
1222   * Fix non-compliance server extension handling. Extensions for SSLv3 are now
1223     ignored, as required by RFC6101.
1224
1225= mbed TLS 2.2.1 released 2016-01-05
1226
1227Security
1228   * Fix potential double free when mbedtls_asn1_store_named_data() fails to
1229     allocate memory. Only used for certificate generation, not triggerable
1230     remotely in SSL/TLS. Found by Rafał Przywara. #367
1231   * Disable MD5 handshake signatures in TLS 1.2 by default to prevent the
1232     SLOTH attack on TLS 1.2 server authentication (other attacks from the
1233     SLOTH paper do not apply to any version of mbed TLS or PolarSSL).
1234     https://www.mitls.org/pages/attacks/SLOTH
1235
1236Bugfix
1237   * Fix over-restrictive length limit in GCM. Found by Andreas-N. #362
1238   * Fix bug in certificate validation that caused valid chains to be rejected
1239     when the first intermediate certificate has pathLenConstraint=0. Found by
1240     Nicholas Wilson. Introduced in mbed TLS 2.2.0. #280
1241   * Removed potential leak in mbedtls_rsa_rsassa_pkcs1_v15_sign(), found by
1242     JayaraghavendranK. #372
1243   * Fix suboptimal handling of unexpected records that caused interop issues
1244     with some peers over unreliable links. Avoid dropping an entire DTLS
1245     datagram if a single record in a datagram is unexpected, instead only
1246     drop the record and look at subsequent records (if any are present) in
1247     the same datagram. Found by jeannotlapin. #345
1248
1249= mbed TLS 2.2.0 released 2015-11-04
1250
1251Security
1252   * Fix potential double free if mbedtls_ssl_conf_psk() is called more than
1253     once and some allocation fails. Cannot be forced remotely. Found by Guido
1254     Vranken, Intelworks.
1255   * Fix potential heap corruption on Windows when
1256     mbedtls_x509_crt_parse_path() is passed a path longer than 2GB. Cannot be
1257     triggered remotely. Found by Guido Vranken, Intelworks.
1258   * Fix potential buffer overflow in some asn1_write_xxx() functions.
1259     Cannot be triggered remotely unless you create X.509 certificates based
1260     on untrusted input or write keys of untrusted origin. Found by Guido
1261     Vranken, Intelworks.
1262   * The X509 max_pathlen constraint was not enforced on intermediate
1263     certificates. Found by Nicholas Wilson, fix and tests provided by
1264     Janos Follath. #280 and #319
1265
1266Features
1267   * Experimental support for EC J-PAKE as defined in Thread 1.0.0.
1268     Disabled by default as the specification might still change.
1269   * Added a key extraction callback to accees the master secret and key
1270     block. (Potential uses include EAP-TLS and Thread.)
1271
1272Bugfix
1273   * Self-signed certificates were not excluded from pathlen counting,
1274     resulting in some valid X.509 being incorrectly rejected. Found and fix
1275     provided by Janos Follath. #319
1276   * Fix build error with configurations where ECDHE-PSK is the only key
1277     exchange. Found and fix provided by Chris Hammond. #270
1278   * Fix build error with configurations where RSA, RSA-PSK, ECDH-RSA or
1279     ECHD-ECDSA if the only key exchange. Multiple reports. #310
1280   * Fixed a bug causing some handshakes to fail due to some non-fatal alerts
1281     not being properly ignored. Found by mancha and Kasom Koht-arsa, #308
1282   * mbedtls_x509_crt_verify(_with_profile)() now also checks the key type and
1283     size/curve against the profile. Before that, there was no way to set a
1284     minimum key size for end-entity certificates with RSA keys. Found by
1285     Matthew Page of Scannex Electronics Ltd.
1286   * Fix failures in MPI on Sparc(64) due to use of bad assembly code.
1287     Found by Kurt Danielson. #292
1288   * Fix typo in name of the extKeyUsage OID. Found by inestlerode, #314
1289   * Fix bug in ASN.1 encoding of booleans that caused generated CA
1290     certificates to be rejected by some applications, including OS X
1291     Keychain. Found and fixed by Jonathan Leroy, Inikup.
1292
1293Changes
1294   * Improved performance of mbedtls_ecp_muladd() when one of the scalars is 1
1295     or -1.
1296
1297= mbed TLS 2.1.2 released 2015-10-06
1298
1299Security
1300   * Added fix for CVE-2015-5291 to prevent heap corruption due to buffer
1301     overflow of the hostname or session ticket. Found by Guido Vranken,
1302     Intelworks.
1303   * Fix potential double-free if mbedtls_ssl_set_hs_psk() is called more than
1304     once in the same handhake and mbedtls_ssl_conf_psk() was used.
1305     Found and patch provided by Guido Vranken, Intelworks. Cannot be forced
1306     remotely.
1307   * Fix stack buffer overflow in pkcs12 decryption (used by
1308     mbedtls_pk_parse_key(file)() when the password is > 129 bytes.
1309     Found by Guido Vranken, Intelworks. Not triggerable remotely.
1310   * Fix potential buffer overflow in mbedtls_mpi_read_string().
1311     Found by Guido Vranken, Intelworks. Not exploitable remotely in the context
1312     of TLS, but might be in other uses. On 32 bit machines, requires reading a
1313     string of close to or larger than 1GB to exploit; on 64 bit machines, would
1314     require reading a string of close to or larger than 2^62 bytes.
1315   * Fix potential random memory allocation in mbedtls_pem_read_buffer()
1316     on crafted PEM input data. Found and fix provided by Guido Vranken,
1317     Intelworks. Not triggerable remotely in TLS. Triggerable remotely if you
1318     accept PEM data from an untrusted source.
1319   * Fix possible heap buffer overflow in base64_encoded() when the input
1320     buffer is 512MB or larger on 32-bit platforms. Found by Guido Vranken,
1321     Intelworks. Not trigerrable remotely in TLS.
1322   * Fix potential double-free if mbedtls_conf_psk() is called repeatedly on
1323     the same mbedtls_ssl_config object and memory allocation fails. Found by
1324     Guido Vranken, Intelworks. Cannot be forced remotely.
1325   * Fix potential heap buffer overflow in servers that perform client
1326     authentication against a crafted CA cert. Cannot be triggered remotely
1327     unless you allow third parties to pick trust CAs for client auth.
1328     Found by Guido Vranken, Intelworks.
1329
1330Bugfix
1331   * Fix compile error in net.c with musl libc. Found and patch provided by
1332     zhasha (#278).
1333   * Fix macroization of 'inline' keyword when building as C++. (#279)
1334
1335Changes
1336   * Added checking of hostname length in mbedtls_ssl_set_hostname() to ensure
1337     domain names are compliant with RFC 1035.
1338   * Fixed paths for check_config.h in example config files. (Found by bachp)
1339     (#291)
1340
1341= mbed TLS 2.1.1 released 2015-09-17
1342
1343Security
1344   * Add countermeasure against Lenstra's RSA-CRT attack for PKCS#1 v1.5
1345     signatures. (Found by Florian Weimer, Red Hat.)
1346     https://securityblog.redhat.com/2015/09/02/factoring-rsa-keys-with-tls-perfect-forward-secrecy/
1347   * Fix possible client-side NULL pointer dereference (read) when the client
1348     tries to continue the handshake after it failed (a misuse of the API).
1349     (Found and patch provided by Fabian Foerg, Gotham Digital Science using
1350     afl-fuzz.)
1351
1352Bugfix
1353   * Fix warning when using a 64bit platform. (found by embedthis) (#275)
1354   * Fix off-by-one error in parsing Supported Point Format extension that
1355     caused some handshakes to fail.
1356
1357Changes
1358   * Made X509 profile pointer const in mbedtls_ssl_conf_cert_profile() to allow
1359     use of mbedtls_x509_crt_profile_next. (found by NWilson)
1360   * When a client initiates a reconnect from the same port as a live
1361     connection, if cookie verification is available
1362     (MBEDTLS_SSL_DTLS_HELLO_VERIFY defined in config.h, and usable cookie
1363     callbacks set with mbedtls_ssl_conf_dtls_cookies()), this will be
1364     detected and mbedtls_ssl_read() will return
1365     MBEDTLS_ERR_SSL_CLIENT_RECONNECT - it is then possible to start a new
1366     handshake with the same context. (See RFC 6347 section 4.2.8.)
1367
1368= mbed TLS 2.1.0 released 2015-09-04
1369
1370Features
1371   * Added support for yotta as a build system.
1372   * Primary open source license changed to Apache 2.0 license.
1373
1374Bugfix
1375   * Fix segfault in the benchmark program when benchmarking DHM.
1376   * Fix build error with CMake and pre-4.5 versions of GCC (found by Hugo
1377     Leisink).
1378   * Fix bug when parsing a ServerHello without extensions (found by David
1379     Sears).
1380   * Fix bug in CMake lists that caused libmbedcrypto.a not to be installed
1381     (found by Benoit Lecocq).
1382   * Fix bug in Makefile that caused libmbedcrypto and libmbedx509 not to be
1383     installed (found by Rawi666).
1384   * Fix compile error with armcc 5 with --gnu option.
1385   * Fix bug in Makefile that caused programs not to be installed correctly
1386     (found by robotanarchy) (#232).
1387   * Fix bug in Makefile that prevented from installing without building the
1388     tests (found by robotanarchy) (#232).
1389   * Fix missing -static-libgcc when building shared libraries for Windows
1390     with make.
1391   * Fix link error when building shared libraries for Windows with make.
1392   * Fix error when loading libmbedtls.so.
1393   * Fix bug in mbedtls_ssl_conf_default() that caused the default preset to
1394     be always used (found by dcb314) (#235)
1395   * Fix bug in mbedtls_rsa_public() and mbedtls_rsa_private() that could
1396     result trying to unlock an unlocked mutex on invalid input (found by
1397     Fredrik Axelsson) (#257)
1398   * Fix -Wshadow warnings (found by hnrkp) (#240)
1399   * Fix memory corruption on client with overlong PSK identity, around
1400     SSL_MAX_CONTENT_LEN or higher - not triggerrable remotely (found by
1401     Aleksandrs Saveljevs) (#238)
1402   * Fix unused function warning when using MBEDTLS_MDx_ALT or
1403     MBEDTLS_SHAxxx_ALT (found by Henrik) (#239)
1404   * Fix memory corruption in pkey programs (found by yankuncheng) (#210)
1405
1406Changes
1407   * The PEM parser now accepts a trailing space at end of lines (#226).
1408   * It is now possible to #include a user-provided configuration file at the
1409     end of the default config.h by defining MBEDTLS_USER_CONFIG_FILE on the
1410     compiler's command line.
1411   * When verifying a certificate chain, if an intermediate certificate is
1412     trusted, no later cert is checked. (suggested by hannes-landeholm)
1413     (#220).
1414   * Prepend a "thread identifier" to debug messages (issue pointed out by
1415     Hugo Leisink) (#210).
1416   * Add mbedtls_ssl_get_max_frag_len() to query the current maximum fragment
1417     length.
1418
1419= mbed TLS 2.0.0 released 2015-07-13
1420
1421Features
1422   * Support for DTLS 1.0 and 1.2 (RFC 6347).
1423   * Ability to override core functions from MDx, SHAx, AES and DES modules
1424     with custom implementation (eg hardware accelerated), complementing the
1425     ability to override the whole module.
1426   * New server-side implementation of session tickets that rotate keys to
1427     preserve forward secrecy, and allows sharing across multiple contexts.
1428   * Added a concept of X.509 cerificate verification profile that controls
1429     which algorithms and key sizes (curves for ECDSA) are acceptable.
1430   * Expanded configurability of security parameters in the SSL module with
1431     mbedtls_ssl_conf_dhm_min_bitlen() and mbedtls_ssl_conf_sig_hashes().
1432   * Introduced a concept of presets for SSL security-relevant configuration
1433     parameters.
1434
1435API Changes
1436   * The library has been split into libmbedcrypto, libmbedx509, libmbedtls.
1437     You now need to link to all of them if you use TLS for example.
1438   * All public identifiers moved to the mbedtls_* or MBEDTLS_* namespace.
1439     Some names have been further changed to make them more consistent.
1440     Migration helpers scripts/rename.pl and include/mbedlts/compat-1.3.h are
1441     provided. Full list of renamings in scripts/data_files/rename-1.3-2.0.txt
1442   * Renamings of fields inside structures, not covered by the previous list:
1443     mbedtls_cipher_info_t.key_length -> key_bitlen
1444     mbedtls_cipher_context_t.key_length -> key_bitlen
1445     mbedtls_ecp_curve_info.size -> bit_size
1446   * Headers are now found in the 'mbedtls' directory (previously 'polarssl').
1447   * The following _init() functions that could return errors have
1448     been split into an _init() that returns void and another function that
1449     should generally be the first function called on this context after init:
1450     mbedtls_ssl_init() -> mbedtls_ssl_setup()
1451     mbedtls_ccm_init() -> mbedtls_ccm_setkey()
1452     mbedtls_gcm_init() -> mbedtls_gcm_setkey()
1453     mbedtls_hmac_drbg_init() -> mbedtls_hmac_drbg_seed(_buf)()
1454     mbedtls_ctr_drbg_init()  -> mbedtls_ctr_drbg_seed()
1455     Note that for mbedtls_ssl_setup(), you need to be done setting up the
1456     ssl_config structure before calling it.
1457   * Most ssl_set_xxx() functions (all except ssl_set_bio(), ssl_set_hostname(),
1458     ssl_set_session() and ssl_set_client_transport_id(), plus
1459     ssl_legacy_renegotiation()) have been renamed to mbedtls_ssl_conf_xxx()
1460     (see rename.pl and compat-1.3.h above) and their first argument's type
1461     changed from ssl_context to ssl_config.
1462   * ssl_set_bio() changed signature (contexts merged, order switched, one
1463     additional callback for read-with-timeout).
1464   * The following functions have been introduced and must be used in callback
1465     implementations (SNI, PSK) instead of their *conf counterparts:
1466     mbedtls_ssl_set_hs_own_cert()
1467     mbedtls_ssl_set_hs_ca_chain()
1468     mbedtls_ssl_set_hs_psk()
1469   * mbedtls_ssl_conf_ca_chain() lost its last argument (peer_cn), now set
1470     using mbedtls_ssl_set_hostname().
1471   * mbedtls_ssl_conf_session_cache() changed prototype (only one context
1472     pointer, parameters reordered).
1473   * On server, mbedtls_ssl_conf_session_tickets_cb() must now be used in
1474     place of mbedtls_ssl_conf_session_tickets() to enable session tickets.
1475   * The SSL debug callback gained two new arguments (file name, line number).
1476   * Debug modes were removed.
1477   * mbedtls_ssl_conf_truncated_hmac() now returns void.
1478   * mbedtls_memory_buffer_alloc_init() now returns void.
1479   * X.509 verification flags are now an uint32_t. Affect the signature of:
1480     mbedtls_ssl_get_verify_result()
1481     mbedtls_x509_ctr_verify_info()
1482     mbedtls_x509_crt_verify() (flags, f_vrfy -> needs to be updated)
1483     mbedtls_ssl_conf_verify() (f_vrfy -> needs to be updated)
1484   * The following functions changed prototype to avoid an in-out length
1485     parameter:
1486     mbedtls_base64_encode()
1487     mbedtls_base64_decode()
1488     mbedtls_mpi_write_string()
1489     mbedtls_dhm_calc_secret()
1490   * In the NET module, all "int" and "int *" arguments for file descriptors
1491     changed type to "mbedtls_net_context *".
1492   * net_accept() gained new arguments for the size of the client_ip buffer.
1493   * In the threading layer, mbedtls_mutex_init() and mbedtls_mutex_free() now
1494     return void.
1495   * ecdsa_write_signature() gained an addtional md_alg argument and
1496     ecdsa_write_signature_det() was deprecated.
1497   * pk_sign() no longer accepts md_alg == POLARSSL_MD_NONE with ECDSA.
1498   * Last argument of x509_crt_check_key_usage() and
1499     mbedtls_x509write_crt_set_key_usage() changed from int to unsigned.
1500   * test_ca_list (from certs.h) is renamed to test_cas_pem and is only
1501     available if POLARSSL_PEM_PARSE_C is defined (it never worked without).
1502   * Test certificates in certs.c are no longer guaranteed to be nul-terminated
1503     strings; use the new *_len variables instead of strlen().
1504   * Functions mbedtls_x509_xxx_parse(), mbedtls_pk_parse_key(),
1505     mbedtls_pk_parse_public_key() and mbedtls_dhm_parse_dhm() now expect the
1506     length parameter to include the terminating null byte for PEM input.
1507   * Signature of mpi_mul_mpi() changed to make the last argument unsigned
1508   * calloc() is now used instead of malloc() everywhere. API of platform
1509     layer and the memory_buffer_alloc module changed accordingly.
1510     (Thanks to Mansour Moufid for helping with the replacement.)
1511   * Change SSL_DISABLE_RENEGOTIATION config.h flag to SSL_RENEGOTIATION
1512     (support for renegotiation now needs explicit enabling in config.h).
1513   * Split MBEDTLS_HAVE_TIME into MBEDTLS_HAVE_TIME and MBEDTLS_HAVE_TIME_DATE
1514     in config.h
1515   * net_connect() and net_bind() have a new 'proto' argument to choose
1516     between TCP and UDP, using the macros NET_PROTO_TCP or NET_PROTO_UDP.
1517     Their 'port' argument type is changed to a string.
1518   * Some constness fixes
1519
1520Removals
1521   * Removed mbedtls_ecp_group_read_string(). Only named groups are supported.
1522   * Removed mbedtls_ecp_sub() and mbedtls_ecp_add(), use
1523     mbedtls_ecp_muladd().
1524   * Removed individual mdX_hmac, shaX_hmac, mdX_file and shaX_file functions
1525     (use generic functions from md.h)
1526   * Removed mbedtls_timing_msleep(). Use mbedtls_net_usleep() or a custom
1527     waiting function.
1528   * Removed test DHM parameters from the test certs module.
1529   * Removed the PBKDF2 module (use PKCS5).
1530   * Removed POLARSSL_ERROR_STRERROR_BC (use mbedtls_strerror()).
1531   * Removed compat-1.2.h (helper for migrating from 1.2 to 1.3).
1532   * Removed openssl.h (very partial OpenSSL compatibility layer).
1533   * Configuration options POLARSSL_HAVE_LONGLONG was removed (now always on).
1534   * Configuration options POLARSSL_HAVE_INT8 and POLARSSL_HAVE_INT16 have
1535     been removed (compiler is required to support 32-bit operations).
1536   * Configuration option POLARSSL_HAVE_IPV6 was removed (always enabled).
1537   * Removed test program o_p_test, the script compat.sh does more.
1538   * Removed test program ssl_test, superseded by ssl-opt.sh.
1539   * Removed helper script active-config.pl
1540
1541New deprecations
1542   * md_init_ctx() is deprecated in favour of md_setup(), that adds a third
1543     argument (allowing memory savings if HMAC is not used)
1544
1545Semi-API changes (technically public, morally private)
1546   * Renamed a few headers to include _internal in the name. Those headers are
1547     not supposed to be included by users.
1548   * Changed md_info_t into an opaque structure (use md_get_xxx() accessors).
1549   * Changed pk_info_t into an opaque structure.
1550   * Changed cipher_base_t into an opaque structure.
1551   * Removed sig_oid2 and rename sig_oid1 to sig_oid in x509_crt and x509_crl.
1552   * x509_crt.key_usage changed from unsigned char to unsigned int.
1553   * Removed r and s from ecdsa_context
1554   * Removed mode from des_context and des3_context
1555
1556Default behavior changes
1557   * The default minimum TLS version is now TLS 1.0.
1558   * RC4 is now blacklisted by default in the SSL/TLS layer, and excluded from the
1559     default ciphersuite list returned by ssl_list_ciphersuites()
1560   * Support for receiving SSLv2 ClientHello is now disabled by default at
1561     compile time.
1562   * The default authmode for SSL/TLS clients is now REQUIRED.
1563   * Support for RSA_ALT contexts in the PK layer is now optional. Since is is
1564     enabled in the default configuration, this is only noticeable if using a
1565     custom config.h
1566   * Default DHM parameters server-side upgraded from 1024 to 2048 bits.
1567   * A minimum RSA key size of 2048 bits is now enforced during ceritificate
1568     chain verification.
1569   * Negotiation of truncated HMAC is now disabled by default on server too.
1570   * The following functions are now case-sensitive:
1571     mbedtls_cipher_info_from_string()
1572     mbedtls_ecp_curve_info_from_name()
1573     mbedtls_md_info_from_string()
1574     mbedtls_ssl_ciphersuite_from_string()
1575     mbedtls_version_check_feature()
1576
1577Requirement changes
1578   * The minimum MSVC version required is now 2010 (better C99 support).
1579   * The NET layer now unconditionnaly relies on getaddrinfo() and select().
1580   * Compiler is required to support C99 types such as long long and uint32_t.
1581
1582API changes from the 1.4 preview branch
1583   * ssl_set_bio_timeout() was removed, split into mbedtls_ssl_set_bio() with
1584     new prototype, and mbedtls_ssl_set_read_timeout().
1585   * The following functions now return void:
1586     mbedtls_ssl_conf_transport()
1587     mbedtls_ssl_conf_max_version()
1588     mbedtls_ssl_conf_min_version()
1589   * DTLS no longer hard-depends on TIMING_C, but uses a callback interface
1590     instead, see mbedtls_ssl_set_timer_cb(), with the Timing module providing
1591     an example implementation, see mbedtls_timing_delay_context and
1592     mbedtls_timing_set/get_delay().
1593   * With UDP sockets, it is no longer necessary to call net_bind() again
1594     after a successful net_accept().
1595
1596Changes
1597   * mbedtls_ctr_drbg_random() and mbedtls_hmac_drbg_random() are now
1598     thread-safe if MBEDTLS_THREADING_C is enabled.
1599   * Reduced ROM fooprint of SHA-256 and added an option to reduce it even
1600     more (at the expense of performance) MBEDTLS_SHA256_SMALLER.
1601
1602= mbed TLS 1.3 branch
1603
1604Security
1605   * With authmode set to SSL_VERIFY_OPTIONAL, verification of keyUsage and
1606     extendedKeyUsage on the leaf certificate was lost (results not accessible
1607     via ssl_get_verify_results()).
1608   * Add countermeasure against "Lucky 13 strikes back" cache-based attack,
1609     https://dl.acm.org/citation.cfm?id=2714625
1610
1611Features
1612   * Improve ECC performance by using more efficient doubling formulas
1613     (contributed by Peter Dettman).
1614   * Add x509_crt_verify_info() to display certificate verification results.
1615   * Add support for reading DH parameters with privateValueLength included
1616     (contributed by Daniel Kahn Gillmor).
1617   * Add support for bit strings in X.509 names (request by Fredrik Axelsson).
1618   * Add support for id-at-uniqueIdentifier in X.509 names.
1619   * Add support for overriding snprintf() (except on Windows) and exit() in
1620     the platform layer.
1621   * Add an option to use macros instead of function pointers in the platform
1622     layer (helps get rid of unwanted references).
1623   * Improved Makefiles for Windows targets by fixing library targets and making
1624     cross-compilation easier (thanks to Alon Bar-Lev).
1625   * The benchmark program also prints heap usage for public-key primitives
1626     if POLARSSL_MEMORY_BUFFER_ALLOC_C and POLARSSL_MEMORY_DEBUG are defined.
1627   * New script ecc-heap.sh helps measuring the impact of ECC parameters on
1628     speed and RAM (heap only for now) usage.
1629   * New script memory.sh helps measuring the ROM and RAM requirements of two
1630     reduced configurations (PSK-CCM and NSA suite B).
1631   * Add config flag POLARSSL_DEPRECATED_WARNING (off by default) to produce
1632     warnings on use of deprecated functions (with GCC and Clang only).
1633   * Add config flag POLARSSL_DEPRECATED_REMOVED (off by default) to produce
1634     errors on use of deprecated functions.
1635
1636Bugfix
1637   * Fix compile errors with PLATFORM_NO_STD_FUNCTIONS.
1638   * Fix compile error with PLATFORM_EXIT_ALT (thanks to Rafał Przywara).
1639   * Fix bug in entropy.c when THREADING_C is also enabled that caused
1640     entropy_free() to crash (thanks to Rafał Przywara).
1641   * Fix memory leak when gcm_setkey() and ccm_setkey() are used more than
1642     once on the same context.
1643   * Fix bug in ssl_mail_client when password is longer that username (found
1644     by Bruno Pape).
1645   * Fix undefined behaviour (memcmp( NULL, NULL, 0 );) in X.509 modules
1646     (detected by Clang's 3.6 UBSan).
1647   * mpi_size() and mpi_msb() would segfault when called on an mpi that is
1648     initialized but not set (found by pravic).
1649   * Fix detection of support for getrandom() on Linux (reported by syzzer) by
1650     doing it at runtime (using uname) rather that compile time.
1651   * Fix handling of symlinks by "make install" (found by Gaël PORTAY).
1652   * Fix potential NULL pointer dereference (not trigerrable remotely) when
1653     ssl_write() is called before the handshake is finished (introduced in
1654     1.3.10) (first reported by Martin Blumenstingl).
1655   * Fix bug in pk_parse_key() that caused some valid private EC keys to be
1656     rejected.
1657   * Fix bug in Via Padlock support (found by Nikos Mavrogiannopoulos).
1658   * Fix thread safety bug in RSA operations (found by Fredrik Axelsson).
1659   * Fix hardclock() (only used in the benchmarking program) with some
1660     versions of mingw64 (found by kxjhlele).
1661   * Fix warnings from mingw64 in timing.c (found by kxjklele).
1662   * Fix potential unintended sign extension in asn1_get_len() on 64-bit
1663     platforms.
1664   * Fix potential memory leak in ssl_set_psk() (found by Mansour Moufid).
1665   * Fix compile error when POLARSSL_SSL_DISABLE_RENEGOTATION and
1666     POLARSSL_SSL_SSESSION_TICKETS where both enabled in config.h (introduced
1667     in 1.3.10).
1668   * Add missing extern "C" guard in aesni.h (reported by amir zamani).
1669   * Add missing dependency on SHA-256 in some x509 programs (reported by
1670     Gergely Budai).
1671   * Fix bug related to ssl_set_curves(): the client didn't check that the
1672     curve picked by the server was actually allowed.
1673
1674Changes
1675   * Remove bias in mpi_gen_prime (contributed by Pascal Junod).
1676   * Remove potential sources of timing variations (some contributed by Pascal
1677     Junod).
1678   * Options POLARSSL_HAVE_INT8 and POLARSSL_HAVE_INT16 are deprecated.
1679   * Enabling POLARSSL_NET_C without POLARSSL_HAVE_IPV6 is deprecated.
1680   * compat-1.2.h and openssl.h are deprecated.
1681   * Adjusting/overriding CFLAGS and LDFLAGS with the make build system is now
1682     more flexible (warning: OFLAGS is not used any more) (see the README)
1683     (contributed by Alon Bar-Lev).
1684   * ssl_set_own_cert() no longer calls pk_check_pair() since the
1685     performance impact was bad for some users (this was introduced in 1.3.10).
1686   * Move from SHA-1 to SHA-256 in example programs using signatures
1687     (suggested by Thorsten Mühlfelder).
1688   * Remove some unneeded inclusions of header files from the standard library
1689     "minimize" others (eg use stddef.h if only size_t is needed).
1690   * Change #include lines in test files to use double quotes instead of angle
1691     brackets for uniformity with the rest of the code.
1692   * Remove dependency on sscanf() in X.509 parsing modules.
1693
1694= mbed TLS 1.3.10 released 2015-02-09
1695Security
1696   * NULL pointer dereference in the buffer-based allocator when the buffer is
1697     full and polarssl_free() is called (found by Mark Hasemeyer)
1698     (only possible if POLARSSL_MEMORY_BUFFER_ALLOC_C is enabled, which it is
1699     not by default).
1700   * Fix remotely-triggerable uninitialised pointer dereference caused by
1701     crafted X.509 certificate (TLS server is not affected if it doesn't ask for a
1702     client certificate) (found using Codenomicon Defensics).
1703   * Fix remotely-triggerable memory leak caused by crafted X.509 certificates
1704     (TLS server is not affected if it doesn't ask for a client certificate)
1705     (found using Codenomicon Defensics).
1706   * Fix potential stack overflow while parsing crafted X.509 certificates
1707     (TLS server is not affected if it doesn't ask for a client certificate)
1708     (found using Codenomicon Defensics).
1709   * Fix timing difference that could theoretically lead to a
1710     Bleichenbacher-style attack in the RSA and RSA-PSK key exchanges
1711     (reported by Sebastian Schinzel).
1712
1713Features
1714   * Add support for FALLBACK_SCSV (draft-ietf-tls-downgrade-scsv).
1715   * Add support for Extended Master Secret (draft-ietf-tls-session-hash).
1716   * Add support for Encrypt-then-MAC (RFC 7366).
1717   * Add function pk_check_pair() to test if public and private keys match.
1718   * Add x509_crl_parse_der().
1719   * Add compile-time option POLARSSL_X509_MAX_INTERMEDIATE_CA to limit the
1720     length of an X.509 verification chain.
1721   * Support for renegotiation can now be disabled at compile-time
1722   * Support for 1/n-1 record splitting, a countermeasure against BEAST.
1723   * Certificate selection based on signature hash, preferring SHA-1 over SHA-2
1724     for pre-1.2 clients when multiple certificates are available.
1725   * Add support for getrandom() syscall on recent Linux kernels with Glibc or
1726     a compatible enough libc (eg uClibc).
1727   * Add ssl_set_arc4_support() to make it easier to disable RC4 at runtime
1728     while using the default ciphersuite list.
1729   * Added new error codes and debug messages about selection of
1730     ciphersuite/certificate.
1731
1732Bugfix
1733   * Stack buffer overflow if ctr_drbg_update() is called with too large
1734     add_len (found by Jean-Philippe Aumasson) (not triggerable remotely).
1735   * Possible buffer overflow of length at most POLARSSL_MEMORY_ALIGN_MULTIPLE
1736     if memory_buffer_alloc_init() was called with buf not aligned and len not
1737     a multiple of POLARSSL_MEMORY_ALIGN_MULTIPLE (not triggerable remotely).
1738   * User set CFLAGS were ignored by Cmake with gcc (introduced in 1.3.9, found
1739     by Julian Ospald).
1740   * Fix potential undefined behaviour in Camellia.
1741   * Fix potential failure in ECDSA signatures when POLARSSL_ECP_MAX_BITS is a
1742     multiple of 8 (found by Gergely Budai).
1743   * Fix unchecked return code in x509_crt_parse_path() on Windows (found by
1744     Peter Vaskovic).
1745   * Fix assembly selection for MIPS64 (thanks to James Cowgill).
1746   * ssl_get_verify_result() now works even if the handshake was aborted due
1747     to a failed verification (found by Fredrik Axelsson).
1748   * Skip writing and parsing signature_algorithm extension if none of the
1749     key exchanges enabled needs certificates. This fixes a possible interop
1750     issue with some servers when a zero-length extension was sent. (Reported
1751     by Peter Dettman.)
1752   * On a 0-length input, base64_encode() did not correctly set output length
1753     (found by Hendrik van den Boogaard).
1754
1755Changes
1756   * Use deterministic nonces for AEAD ciphers in TLS by default (possible to
1757     switch back to random with POLARSSL_SSL_AEAD_RANDOM_IV in config.h).
1758   * Blind RSA private operations even when POLARSSL_RSA_NO_CRT is defined.
1759   * ssl_set_own_cert() now returns an error on key-certificate mismatch.
1760   * Forbid repeated extensions in X.509 certificates.
1761   * debug_print_buf() now prints a text view in addition to hexadecimal.
1762   * A specific error is now returned when there are ciphersuites in common
1763     but none of them is usable due to external factors such as no certificate
1764     with a suitable (extended)KeyUsage or curve or no PSK set.
1765   * It is now possible to disable negotiation of truncated HMAC server-side
1766     at runtime with ssl_set_truncated_hmac().
1767   * Example programs for SSL client and server now disable SSLv3 by default.
1768   * Example programs for SSL client and server now disable RC4 by default.
1769   * Use platform.h in all test suites and programs.
1770
1771= PolarSSL 1.3.9 released 2014-10-20
1772Security
1773   * Lowest common hash was selected from signature_algorithms extension in
1774     TLS 1.2 (found by Darren Bane) (introduced in 1.3.8).
1775   * Remotely-triggerable memory leak when parsing some X.509 certificates
1776     (server is not affected if it doesn't ask for a client certificate)
1777     (found using Codenomicon Defensics).
1778   * Remotely-triggerable memory leak when parsing crafted ClientHello
1779     (not affected if ECC support was compiled out) (found using Codenomicon
1780     Defensics).
1781
1782Bugfix
1783   * Support escaping of commas in x509_string_to_names()
1784   * Fix compile error in ssl_pthread_server (found by Julian Ospald).
1785   * Fix net_accept() regarding non-blocking sockets (found by Luca Pesce).
1786   * Don't print uninitialised buffer in ssl_mail_client (found by Marc Abel).
1787   * Fix warnings from Clang's scan-build (contributed by Alfred Klomp).
1788   * Fix compile error in timing.c when POLARSSL_NET_C and POLARSSL_SELFTEST
1789     are defined but not POLARSSL_HAVE_TIME (found by Stephane Di Vito).
1790   * Remove non-existent file from VS projects (found by Peter Vaskovic).
1791   * ssl_read() could return non-application data records on server while
1792     renegotation was pending, and on client when a HelloRequest was received.
1793   * Server-initiated renegotiation would fail with non-blocking I/O if the
1794     write callback returned WANT_WRITE when requesting renegotiation.
1795   * ssl_close_notify() could send more than one message in some circumstances
1796     with non-blocking I/O.
1797   * Fix compiler warnings on iOS (found by Sander Niemeijer).
1798   * x509_crt_parse() did not increase total_failed on PEM error
1799   * Fix compile error with armcc in mpi_is_prime()
1800   * Fix potential bad read in parsing ServerHello (found by Adrien
1801     Vialletelle).
1802
1803Changes
1804   * Ciphersuites using SHA-256 or SHA-384 now require TLS 1.x (there is no
1805     standard defining how to use SHA-2 with SSL 3.0).
1806   * Ciphersuites using RSA-PSK key exchange new require TLS 1.x (the spec is
1807     ambiguous on how to encode some packets with SSL 3.0).
1808   * Made buffer size in pk_write_(pub)key_pem() more dynamic, eg smaller if
1809     RSA is disabled, larger if POLARSSL_MPI_MAX_SIZE is larger.
1810   * ssl_read() now returns POLARSSL_ERR_NET_WANT_READ rather than
1811     POLARSSL_ERR_SSL_UNEXPECTED_MESSAGE on harmless alerts.
1812   * POLARSSL_MPI_MAX_SIZE now defaults to 1024 in order to allow 8192 bits
1813     RSA keys.
1814   * Accept spaces at end of line or end of buffer in base64_decode().
1815   * X.509 certificates with more than one AttributeTypeAndValue per
1816     RelativeDistinguishedName are not accepted any more.
1817
1818= PolarSSL 1.3.8 released 2014-07-11
1819Security
1820   * Fix length checking for AEAD ciphersuites (found by Codenomicon).
1821     It was possible to crash the server (and client) using crafted messages
1822     when a GCM suite was chosen.
1823
1824Features
1825   * Add CCM module and cipher mode to Cipher Layer
1826   * Support for CCM and CCM_8 ciphersuites
1827   * Support for parsing and verifying RSASSA-PSS signatures in the X.509
1828     modules (certificates, CRLs and CSRs).
1829   * Blowfish in the cipher layer now supports variable length keys.
1830   * Add example config.h for PSK with CCM, optimized for low RAM usage.
1831   * Optimize for RAM usage in example config.h for NSA Suite B profile.
1832   * Add POLARSSL_REMOVE_ARC4_CIPHERSUITES to allow removing RC4 ciphersuites
1833     from the default list (inactive by default).
1834   * Add server-side enforcement of sent renegotiation requests
1835     (ssl_set_renegotiation_enforced())
1836   * Add SSL_CIPHERSUITES config.h flag to allow specifying a list of
1837     ciphersuites to use and save some memory if the list is small.
1838
1839Changes
1840   * Add LINK_WITH_PTHREAD option in CMake for explicit linking that is
1841     required on some platforms (e.g. OpenBSD)
1842   * Migrate zeroizing of data to polarssl_zeroize() instead of memset()
1843     against unwanted compiler optimizations
1844   * md_list() now returns hashes strongest first
1845   * Selection of hash for signing ServerKeyExchange in TLS 1.2 now picks
1846     strongest offered by client.
1847   * All public contexts have _init() and _free() functions now for simpler
1848     usage pattern
1849
1850Bugfix
1851   * Fix in debug_print_msg()
1852   * Enforce alignment in the buffer allocator even if buffer is not aligned
1853   * Remove less-than-zero checks on unsigned numbers
1854   * Stricter check on SSL ClientHello internal sizes compared to actual packet
1855     size (found by TrustInSoft)
1856   * Fix WSAStartup() return value check (found by Peter Vaskovic)
1857   * Other minor issues (found by Peter Vaskovic)
1858   * Fix symlink command for cross compiling with CMake (found by Andre
1859     Heinecke)
1860   * Fix DER output of gen_key app (found by Gergely Budai)
1861   * Very small records were incorrectly rejected when truncated HMAC was in
1862     use with some ciphersuites and versions (RC4 in all versions, CBC with
1863     versions < TLS 1.1).
1864   * Very large records using more than 224 bytes of padding were incorrectly
1865     rejected with CBC-based ciphersuites and TLS >= 1.1
1866   * Very large records using less padding could cause a buffer overread of up
1867     to 32 bytes with CBC-based ciphersuites and TLS >= 1.1
1868   * Restore ability to use a v1 cert as a CA if trusted locally. (This had
1869     been removed in 1.3.6.)
1870   * Restore ability to locally trust a self-signed cert that is not a proper
1871     CA for use as an end entity certificate. (This had been removed in
1872     1.3.6.)
1873   * Fix preprocessor checks for bn_mul PPC asm (found by Barry K. Nathan).
1874   * Use \n\t rather than semicolons for bn_mul asm, since some assemblers
1875     interpret semicolons as comment delimiters (found by Barry K. Nathan).
1876   * Fix off-by-one error in parsing Supported Point Format extension that
1877     caused some handshakes to fail.
1878   * Fix possible miscomputation of the premaster secret with DHE-PSK key
1879     exchange that caused some handshakes to fail with other implementations.
1880     (Failure rate <= 1/255 with common DHM moduli.)
1881   * Disable broken Sparc64 bn_mul assembly (found by Florian Obser).
1882   * Fix base64_decode() to return and check length correctly (in case of
1883     tight buffers)
1884   * Fix mpi_write_string() to write "00" as hex output for empty MPI (found
1885     by Hui Dong)
1886
1887= PolarSSL 1.3.7 released on 2014-05-02
1888Features
1889   * debug_set_log_mode() added to determine raw or full logging
1890   * debug_set_threshold() added to ignore messages over threshold level
1891   * version_check_feature() added to check for compile-time options at
1892     run-time
1893
1894Changes
1895   * POLARSSL_CONFIG_OPTIONS has been removed. All values are individually
1896     checked and filled in the relevant module headers
1897   * Debug module only outputs full lines instead of parts
1898   * Better support for the different Attribute Types from IETF PKIX (RFC 5280)
1899   * AES-NI now compiles with "old" assemblers too
1900   * Ciphersuites based on RC4 now have the lowest priority by default
1901
1902Bugfix
1903   * Only iterate over actual certificates in ssl_write_certificate_request()
1904     (found by Matthew Page)
1905   * Typos in platform.c and pkcs11.c (found by Daniel Phillips and Steffan
1906     Karger)
1907   * cert_write app should use subject of issuer certificate as issuer of cert
1908   * Fix false reject in padding check in ssl_decrypt_buf() for CBC
1909     ciphersuites, for full SSL frames of data.
1910   * Improve interoperability by not writing extension length in ClientHello /
1911     ServerHello when no extensions are present (found by Matthew Page)
1912   * rsa_check_pubkey() now allows an E up to N
1913   * On OpenBSD, use arc4random_buf() instead of rand() to prevent warnings
1914   * mpi_fill_random() was creating numbers larger than requested on
1915     big-endian platform when size was not an integer number of limbs
1916   * Fix dependencies issues in X.509 test suite.
1917   * Some parts of ssl_tls.c were compiled even when the module was disabled.
1918   * Fix detection of DragonflyBSD in net.c (found by Markus Pfeiffer)
1919   * Fix detection of Clang on some Apple platforms with CMake
1920     (found by Barry K. Nathan)
1921
1922= PolarSSL 1.3.6 released on 2014-04-11
1923
1924Features
1925   * Support for the ALPN SSL extension
1926   * Add option 'use_dev_random' to gen_key application
1927   * Enable verification of the keyUsage extension for CA and leaf
1928     certificates (POLARSSL_X509_CHECK_KEY_USAGE)
1929   * Enable verification of the extendedKeyUsage extension
1930     (POLARSSL_X509_CHECK_EXTENDED_KEY_USAGE)
1931
1932Changes
1933   * x509_crt_info() now prints information about parsed extensions as well
1934   * pk_verify() now returns a specific error code when the signature is valid
1935     but shorter than the supplied length.
1936   * Use UTC time to check certificate validity.
1937   * Reject certificates with times not in UTC, per RFC 5280.
1938
1939Security
1940   * Avoid potential timing leak in ecdsa_sign() by blinding modular division.
1941     (Found by Watson Ladd.)
1942   * The notAfter date of some certificates was no longer checked since 1.3.5.
1943     This affects certificates in the user-supplied chain except the top
1944     certificate. If the user-supplied chain contains only one certificates,
1945     it is not affected (ie, its notAfter date is properly checked).
1946   * Prevent potential NULL pointer dereference in ssl_read_record() (found by
1947     TrustInSoft)
1948
1949Bugfix
1950   * The length of various ClientKeyExchange messages was not properly checked.
1951   * Some example server programs were not sending the close_notify alert.
1952   * Potential memory leak in mpi_exp_mod() when error occurs during
1953     calculation of RR.
1954   * Fixed malloc/free default #define in platform.c (found by Gergely Budai).
1955   * Fixed type which made POLARSSL_ENTROPY_FORCE_SHA256 uneffective (found by
1956     Gergely Budai).
1957   * Fix #include path in ecdsa.h which wasn't accepted by some compilers.
1958     (found by Gergely Budai)
1959   * Fix compile errors when POLARSSL_ERROR_STRERROR_BC is undefined (found by
1960     Shuo Chen).
1961   * oid_get_numeric_string() used to truncate the output without returning an
1962     error if the output buffer was just 1 byte too small.
1963   * dhm_parse_dhm() (hence dhm_parse_dhmfile()) did not set dhm->len.
1964   * Calling pk_debug() on an RSA-alt key would segfault.
1965   * pk_get_size() and pk_get_len() were off by a factor 8 for RSA-alt keys.
1966   * Potential buffer overwrite in pem_write_buffer() because of low length
1967     indication (found by Thijs Alkemade)
1968   * EC curves constants, which should be only in ROM since 1.3.3, were also
1969     stored in RAM due to missing 'const's (found by Gergely Budai).
1970
1971= PolarSSL 1.3.5 released on 2014-03-26
1972Features
1973   * HMAC-DRBG as a separate module
1974   * Option to set the Curve preference order (disabled by default)
1975   * Single Platform compatilibity layer (for memory / printf / fprintf)
1976   * Ability to provide alternate timing implementation
1977   * Ability to force the entropy module to use SHA-256 as its basis
1978     (POLARSSL_ENTROPY_FORCE_SHA256)
1979   * Testing script ssl-opt.sh added for testing 'live' ssl option
1980     interoperability against OpenSSL and PolarSSL
1981   * Support for reading EC keys that use SpecifiedECDomain in some cases.
1982   * Entropy module now supports seed writing and reading
1983
1984Changes
1985   * Deprecated the Memory layer
1986   * entropy_add_source(), entropy_update_manual() and entropy_gather()
1987     now thread-safe if POLARSSL_THREADING_C defined
1988   * Improvements to the CMake build system, contributed by Julian Ospald.
1989   * Work around a bug of the version of Clang shipped by Apple with Mavericks
1990     that prevented bignum.c from compiling. (Reported by Rafael Baptista.)
1991   * Revamped the compat.sh interoperatibility script to include support for
1992     testing against GnuTLS
1993   * Deprecated ssl_set_own_cert_rsa() and ssl_set_own_cert_rsa_alt()
1994   * Improvements to tests/Makefile, contributed by Oden Eriksson.
1995
1996Security
1997   * Forbid change of server certificate during renegotiation to prevent
1998     "triple handshake" attack when authentication mode is 'optional' (the
1999     attack was already impossible when authentication is required).
2000   * Check notBefore timestamp of certificates and CRLs from the future.
2001   * Forbid sequence number wrapping
2002   * Fixed possible buffer overflow with overlong PSK
2003   * Possible remotely-triggered out-of-bounds memory access fixed (found by
2004     TrustInSoft)
2005
2006Bugfix
2007   * ecp_gen_keypair() does more tries to prevent failure because of
2008     statistics
2009   * Fixed bug in RSA PKCS#1 v1.5 "reversed" operations
2010   * Fixed testing with out-of-source builds using cmake
2011   * Fixed version-major intolerance in server
2012   * Fixed CMake symlinking on out-of-source builds
2013   * Fixed dependency issues in test suite
2014   * Programs rsa_sign_pss and rsa_verify_pss were not using PSS since 1.3.0
2015   * Bignum's MIPS-32 assembly was used on MIPS-64, causing chaos. (Found by
2016     Alex Wilson.)
2017   * ssl_cache was creating entries when max_entries=0 if TIMING_C was enabled.
2018   * m_sleep() was sleeping twice too long on most Unix platforms.
2019   * Fixed bug with session tickets and non-blocking I/O in the unlikely case
2020     send() would return an EAGAIN error when sending the ticket.
2021   * ssl_cache was leaking memory when reusing a timed out entry containing a
2022     client certificate.
2023   * ssl_srv was leaking memory when client presented a timed out ticket
2024     containing a client certificate
2025   * ssl_init() was leaving a dirty pointer in ssl_context if malloc of
2026     out_ctr failed
2027   * ssl_handshake_init() was leaving dirty pointers in subcontexts if malloc
2028     of one of them failed
2029   * Fix typo in rsa_copy() that impacted PKCS#1 v2 contexts
2030   * x509_get_current_time() uses localtime_r() to prevent thread issues
2031
2032= PolarSSL 1.3.4 released on 2014-01-27
2033Features
2034   * Support for the Koblitz curves: secp192k1, secp224k1, secp256k1
2035   * Support for RIPEMD-160
2036   * Support for AES CFB8 mode
2037   * Support for deterministic ECDSA (RFC 6979)
2038
2039Bugfix
2040   * Potential memory leak in bignum_selftest()
2041   * Replaced expired test certificate
2042   * ssl_mail_client now terminates lines with CRLF, instead of LF
2043   * net module handles timeouts on blocking sockets better (found by Tilman
2044     Sauerbeck)
2045   * Assembly format fixes in bn_mul.h
2046
2047Security
2048   * Missing MPI_CHK calls added around unguarded mpi calls (found by
2049     TrustInSoft)
2050
2051= PolarSSL 1.3.3 released on 2013-12-31
2052Features
2053   * EC key generation support in gen_key app
2054   * Support for adhering to client ciphersuite order preference
2055     (POLARSSL_SSL_SRV_RESPECT_CLIENT_PREFERENCE)
2056   * Support for Curve25519
2057   * Support for ECDH-RSA and ECDH-ECDSA key exchanges and ciphersuites
2058   * Support for IPv6 in the NET module
2059   * AES-NI support for AES, AES-GCM and AES key scheduling
2060   * SSL Pthread-based server example added (ssl_pthread_server)
2061
2062Changes
2063   * gen_prime() speedup
2064   * Speedup of ECP multiplication operation
2065   * Relaxed some SHA2 ciphersuite's version requirements
2066   * Dropped use of readdir_r() instead of readdir() with threading support
2067   * More constant-time checks in the RSA module
2068   * Split off curves from ecp.c into ecp_curves.c
2069   * Curves are now stored fully in ROM
2070   * Memory usage optimizations in ECP module
2071   * Removed POLARSSL_THREADING_DUMMY
2072
2073Bugfix
2074   * Fixed bug in mpi_set_bit() on platforms where t_uint is wider than int
2075   * Fixed X.509 hostname comparison (with non-regular characters)
2076   * SSL now gracefully handles missing RNG
2077   * Missing defines / cases for RSA_PSK key exchange
2078   * crypt_and_hash app checks MAC before final decryption
2079   * Potential memory leak in ssl_ticket_keys_init()
2080   * Memory leak in benchmark application
2081   * Fixed x509_crt_parse_path() bug on Windows platforms
2082   * Added missing MPI_CHK() around some statements in mpi_div_mpi() (found by
2083     TrustInSoft)
2084   * Fixed potential overflow in certificate size verification in
2085     ssl_write_certificate() (found by TrustInSoft)
2086
2087Security
2088   * Possible remotely-triggered out-of-bounds memory access fixed (found by
2089     TrustInSoft)
2090
2091= PolarSSL 1.3.2 released on 2013-11-04
2092Features
2093   * PK tests added to test framework
2094   * Added optional optimization for NIST MODP curves (POLARSSL_ECP_NIST_OPTIM)
2095   * Support for Camellia-GCM mode and ciphersuites
2096
2097Changes
2098   * Padding checks in cipher layer are now constant-time
2099   * Value comparisons in SSL layer are now constant-time
2100   * Support for serialNumber, postalAddress and postalCode in X509 names
2101   * SSL Renegotiation was refactored
2102
2103Bugfix
2104   * More stringent checks in cipher layer
2105   * Server does not send out extensions not advertised by client
2106   * Prevent possible alignment warnings on casting from char * to 'aligned *'
2107   * Misc fixes and additions to dependency checks
2108   * Const correctness
2109   * cert_write with selfsign should use issuer_name as subject_name
2110   * Fix ECDSA corner case: missing reduction mod N (found by DualTachyon)
2111   * Defines to handle UEFI environment under MSVC
2112   * Server-side initiated renegotiations send HelloRequest
2113
2114= PolarSSL 1.3.1 released on 2013-10-15
2115Features
2116   * Support for Brainpool curves and TLS ciphersuites (RFC 7027)
2117   * Support for ECDHE-PSK key-exchange and ciphersuites
2118   * Support for RSA-PSK key-exchange and ciphersuites
2119
2120Changes
2121   * RSA blinding locks for a smaller amount of time
2122   * TLS compression only allocates working buffer once
2123   * Introduced POLARSSL_HAVE_READDIR_R for systems without it
2124   * config.h is more script-friendly
2125
2126Bugfix
2127   * Missing MSVC defines added
2128   * Compile errors with POLARSSL_RSA_NO_CRT
2129   * Header files with 'polarssl/'
2130   * Const correctness
2131   * Possible naming collision in dhm_context
2132   * Better support for MSVC
2133   * threading_set_alt() name
2134   * Added missing x509write_crt_set_version()
2135
2136= PolarSSL 1.3.0 released on 2013-10-01
2137Features
2138   * Elliptic Curve Cryptography module added
2139   * Elliptic Curve Diffie Hellman module added
2140   * Ephemeral Elliptic Curve Diffie Hellman support for SSL/TLS
2141    (ECDHE-based ciphersuites)
2142   * Ephemeral Elliptic Curve Digital Signature Algorithm support for SSL/TLS
2143    (ECDSA-based ciphersuites)
2144   * Ability to specify allowed ciphersuites based on the protocol version.
2145   * PSK and DHE-PSK based ciphersuites added
2146   * Memory allocation abstraction layer added
2147   * Buffer-based memory allocator added (no malloc() / free() / HEAP usage)
2148   * Threading abstraction layer added (dummy / pthread / alternate)
2149   * Public Key abstraction layer added
2150   * Parsing Elliptic Curve keys
2151   * Parsing Elliptic Curve certificates
2152   * Support for max_fragment_length extension (RFC 6066)
2153   * Support for truncated_hmac extension (RFC 6066)
2154   * Support for zeros-and-length (ANSI X.923) padding, one-and-zeros
2155     (ISO/IEC 7816-4) padding and zero padding in the cipher layer
2156   * Support for session tickets (RFC 5077)
2157   * Certificate Request (CSR) generation with extensions (key_usage,
2158     ns_cert_type)
2159   * X509 Certificate writing with extensions (basic_constraints,
2160     issuer_key_identifier, etc)
2161   * Optional blinding for RSA, DHM and EC
2162   * Support for multiple active certificate / key pairs in SSL servers for
2163     the same host (Not to be confused with SNI!)
2164
2165Changes
2166   * Ability to enable / disable SSL v3 / TLS 1.0 / TLS 1.1 / TLS 1.2
2167     individually
2168   * Introduced separate SSL Ciphersuites module that is based on
2169     Cipher and MD information
2170   * Internals for SSL module adapted to have separate IV pointer that is
2171     dynamically set (Better support for hardware acceleration)
2172   * Moved all OID functionality to a separate module. RSA function
2173     prototypes for the RSA sign and verify functions changed as a result
2174   * Split up the GCM module into a starts/update/finish cycle
2175   * Client and server now filter sent and accepted ciphersuites on minimum
2176     and maximum protocol version
2177   * Ability to disable server_name extension (RFC 6066)
2178   * Renamed error_strerror() to the less conflicting polarssl_strerror()
2179     (Ability to keep old as well with POLARSSL_ERROR_STRERROR_BC)
2180   * SHA2 renamed to SHA256, SHA4 renamed to SHA512 and functions accordingly
2181   * All RSA operations require a random generator for blinding purposes
2182   * X509 core refactored
2183   * x509_crt_verify() now case insensitive for cn (RFC 6125 6.4)
2184   * Also compiles / runs without time-based functions (!POLARSSL_HAVE_TIME)
2185   * Support faulty X509 v1 certificates with extensions
2186     (POLARSSL_X509_ALLOW_EXTENSIONS_NON_V3)
2187
2188Bugfix
2189   * Fixed parse error in ssl_parse_certificate_request()
2190   * zlib compression/decompression skipped on empty blocks
2191   * Support for AIX header locations in net.c module
2192   * Fixed file descriptor leaks
2193
2194Security
2195   * RSA blinding on CRT operations to counter timing attacks
2196     (found by Cyril Arnaud and Pierre-Alain Fouque)
2197
2198
2199= Version 1.2.14 released 2015-05-??
2200
2201Security
2202   * Fix potential invalid memory read in the server, that allows a client to
2203     crash it remotely (found by Caj Larsson).
2204   * Fix potential invalid memory read in certificate parsing, that allows a
2205     client to crash the server remotely if client authentication is enabled
2206     (found using Codenomicon Defensics).
2207   * Add countermeasure against "Lucky 13 strikes back" cache-based attack,
2208     https://dl.acm.org/citation.cfm?id=2714625
2209
2210Bugfix
2211   * Fix bug in Via Padlock support (found by Nikos Mavrogiannopoulos).
2212   * Fix hardclock() (only used in the benchmarking program) with some
2213     versions of mingw64 (found by kxjhlele).
2214   * Fix warnings from mingw64 in timing.c (found by kxjklele).
2215   * Fix potential unintended sign extension in asn1_get_len() on 64-bit
2216     platforms (found with Coverity Scan).
2217
2218= Version 1.2.13 released 2015-02-16
2219Note: Although PolarSSL has been renamed to mbed TLS, no changes reflecting
2220      this will be made in the 1.2 branch at this point.
2221
2222Security
2223   * Fix remotely-triggerable uninitialised pointer dereference caused by
2224     crafted X.509 certificate (TLS server is not affected if it doesn't ask
2225     for a client certificate) (found using Codenomicon Defensics).
2226   * Fix remotely-triggerable memory leak caused by crafted X.509 certificates
2227     (TLS server is not affected if it doesn't ask for a client certificate)
2228     (found using Codenomicon Defensics).
2229   * Fix potential stack overflow while parsing crafted X.509 certificates
2230     (TLS server is not affected if it doesn't ask for a client certificate)
2231     found using Codenomicon Defensics).
2232   * Fix buffer overread of size 1 when parsing crafted X.509 certificates
2233     (TLS server is not affected if it doesn't ask for a client certificate).
2234
2235Bugfix
2236   * Fix potential undefined behaviour in Camellia.
2237   * Fix memory leaks in PKCS#5 and PKCS#12.
2238   * Stack buffer overflow if ctr_drbg_update() is called with too large
2239     add_len (found by Jean-Philippe Aumasson) (not triggerable remotely).
2240   * Fix bug in MPI/bignum on s390/s390x (reported by Dan Horák) (introduced
2241     in 1.2.12).
2242   * Fix unchecked return code in x509_crt_parse_path() on Windows (found by
2243     Peter Vaskovic).
2244   * Fix assembly selection for MIPS64 (thanks to James Cowgill).
2245   * ssl_get_verify_result() now works even if the handshake was aborted due
2246     to a failed verification (found by Fredrik Axelsson).
2247   * Skip writing and parsing signature_algorithm extension if none of the
2248     key exchanges enabled needs certificates. This fixes a possible interop
2249     issue with some servers when a zero-length extension was sent. (Reported
2250     by Peter Dettman.)
2251   * On a 0-length input, base64_encode() did not correctly set output length
2252     (found by Hendrik van den Boogaard).
2253
2254Changes
2255   * Blind RSA private operations even when POLARSSL_RSA_NO_CRT is defined.
2256   * Forbid repeated extensions in X.509 certificates.
2257   * Add compile-time option POLARSSL_X509_MAX_INTERMEDIATE_CA to limit the
2258     length of an X.509 verification chain (default = 8).
2259= Version 1.2.12 released 2014-10-24
2260
2261Security
2262   * Remotely-triggerable memory leak when parsing some X.509 certificates
2263     (server is not affected if it doesn't ask for a client certificate).
2264     (Found using Codenomicon Defensics.)
2265
2266Bugfix
2267   * Fix potential bad read in parsing ServerHello (found by Adrien
2268     Vialletelle).
2269   * ssl_close_notify() could send more than one message in some circumstances
2270     with non-blocking I/O.
2271   * x509_crt_parse() did not increase total_failed on PEM error
2272   * Fix compiler warnings on iOS (found by Sander Niemeijer).
2273   * Don't print uninitialised buffer in ssl_mail_client (found by Marc Abel).
2274   * Fix net_accept() regarding non-blocking sockets (found by Luca Pesce).
2275   * ssl_read() could return non-application data records on server while
2276     renegotation was pending, and on client when a HelloRequest was received.
2277   * Fix warnings from Clang's scan-build (contributed by Alfred Klomp).
2278
2279Changes
2280   * X.509 certificates with more than one AttributeTypeAndValue per
2281     RelativeDistinguishedName are not accepted any more.
2282   * ssl_read() now returns POLARSSL_ERR_NET_WANT_READ rather than
2283     POLARSSL_ERR_SSL_UNEXPECTED_MESSAGE on harmless alerts.
2284   * Accept spaces at end of line or end of buffer in base64_decode().
2285
2286= Version 1.2.11 released 2014-07-11
2287Features
2288   * Entropy module now supports seed writing and reading
2289
2290Changes
2291   * Introduced POLARSSL_HAVE_READDIR_R for systems without it
2292   * Improvements to the CMake build system, contributed by Julian Ospald.
2293   * Work around a bug of the version of Clang shipped by Apple with Mavericks
2294     that prevented bignum.c from compiling. (Reported by Rafael Baptista.)
2295   * Improvements to tests/Makefile, contributed by Oden Eriksson.
2296   * Use UTC time to check certificate validity.
2297   * Reject certificates with times not in UTC, per RFC 5280.
2298   * Migrate zeroizing of data to polarssl_zeroize() instead of memset()
2299     against unwanted compiler optimizations
2300
2301Security
2302   * Forbid change of server certificate during renegotiation to prevent
2303     "triple handshake" attack when authentication mode is optional (the
2304     attack was already impossible when authentication is required).
2305   * Check notBefore timestamp of certificates and CRLs from the future.
2306   * Forbid sequence number wrapping
2307   * Prevent potential NULL pointer dereference in ssl_read_record() (found by
2308     TrustInSoft)
2309   * Fix length checking for AEAD ciphersuites (found by Codenomicon).
2310     It was possible to crash the server (and client) using crafted messages
2311     when a GCM suite was chosen.
2312
2313Bugfix
2314   * Fixed X.509 hostname comparison (with non-regular characters)
2315   * SSL now gracefully handles missing RNG
2316   * crypt_and_hash app checks MAC before final decryption
2317   * Fixed x509_crt_parse_path() bug on Windows platforms
2318   * Added missing MPI_CHK() around some statements in mpi_div_mpi() (found by
2319     TrustInSoft)
2320   * Fixed potential overflow in certificate size verification in
2321     ssl_write_certificate() (found by TrustInSoft)
2322   * Fix ASM format in bn_mul.h
2323   * Potential memory leak in bignum_selftest()
2324   * Replaced expired test certificate
2325   * ssl_mail_client now terminates lines with CRLF, instead of LF
2326   * Fix bug in RSA PKCS#1 v1.5 "reversed" operations
2327   * Fixed testing with out-of-source builds using cmake
2328   * Fixed version-major intolerance in server
2329   * Fixed CMake symlinking on out-of-source builds
2330   * Bignum's MIPS-32 assembly was used on MIPS-64, causing chaos. (Found by
2331     Alex Wilson.)
2332   * ssl_init() was leaving a dirty pointer in ssl_context if malloc of
2333     out_ctr failed
2334   * ssl_handshake_init() was leaving dirty pointers in subcontexts if malloc
2335     of one of them failed
2336   * x509_get_current_time() uses localtime_r() to prevent thread issues
2337   * Some example server programs were not sending the close_notify alert.
2338   * Potential memory leak in mpi_exp_mod() when error occurs during
2339     calculation of RR.
2340   * Improve interoperability by not writing extension length in ClientHello
2341     when no extensions are present (found by Matthew Page)
2342   * rsa_check_pubkey() now allows an E up to N
2343   * On OpenBSD, use arc4random_buf() instead of rand() to prevent warnings
2344   * mpi_fill_random() was creating numbers larger than requested on
2345     big-endian platform when size was not an integer number of limbs
2346   * Fix detection of DragonflyBSD in net.c (found by Markus Pfeiffer)
2347   * Stricter check on SSL ClientHello internal sizes compared to actual packet
2348     size (found by TrustInSoft)
2349   * Fix preprocessor checks for bn_mul PPC asm (found by Barry K. Nathan).
2350   * Use \n\t rather than semicolons for bn_mul asm, since some assemblers
2351     interpret semicolons as comment delimiters (found by Barry K. Nathan).
2352   * Disable broken Sparc64 bn_mul assembly (found by Florian Obser).
2353   * Fix base64_decode() to return and check length correctly (in case of
2354     tight buffers)
2355
2356= Version 1.2.10 released 2013-10-07
2357Changes
2358   * Changed RSA blinding to a slower but thread-safe version
2359
2360Bugfix
2361   * Fixed memory leak in RSA as a result of introduction of blinding
2362   * Fixed ssl_pkcs11_decrypt() prototype
2363   * Fixed MSVC project files
2364
2365= Version 1.2.9 released 2013-10-01
2366Changes
2367   * x509_verify() now case insensitive for cn (RFC 6125 6.4)
2368
2369Bugfix
2370   * Fixed potential memory leak when failing to resume a session
2371   * Fixed potential file descriptor leaks (found by Remi Gacogne)
2372   * Minor fixes
2373
2374Security
2375   * Fixed potential heap buffer overflow on large hostname setting
2376   * Fixed potential negative value misinterpretation in load_file()
2377   * RSA blinding on CRT operations to counter timing attacks
2378     (found by Cyril Arnaud and Pierre-Alain Fouque)
2379
2380= Version 1.2.8 released 2013-06-19
2381Features
2382   * Parsing of PKCS#8 encrypted private key files
2383   * PKCS#12 PBE and derivation functions
2384   * Centralized module option values in config.h to allow user-defined
2385     settings without editing header files by using POLARSSL_CONFIG_OPTIONS
2386
2387Changes
2388   * HAVEGE random generator disabled by default
2389   * Internally split up x509parse_key() into a (PEM) handler function
2390     and specific DER parser functions for the PKCS#1 and unencrypted
2391     PKCS#8 private key formats
2392   * Added mechanism to provide alternative implementations for all
2393     symmetric cipher and hash algorithms (e.g. POLARSSL_AES_ALT in
2394     config.h)
2395   * PKCS#5 module added. Moved PBKDF2 functionality inside and deprecated
2396     old PBKDF2 module
2397
2398Bugfix
2399   * Secure renegotiation extension should only be sent in case client
2400     supports secure renegotiation
2401   * Fixed offset for cert_type list in ssl_parse_certificate_request()
2402   * Fixed const correctness issues that have no impact on the ABI
2403   * x509parse_crt() now better handles PEM error situations
2404   * ssl_parse_certificate() now calls x509parse_crt_der() directly
2405     instead of the x509parse_crt() wrapper that can also parse PEM
2406     certificates
2407   * x509parse_crtpath() is now reentrant and uses more portable stat()
2408   * Fixed bignum.c and bn_mul.h to support Thumb2 and LLVM compiler
2409   * Fixed values for 2-key Triple DES in cipher layer
2410   * ssl_write_certificate_request() can handle empty ca_chain
2411
2412Security
2413   * A possible DoS during the SSL Handshake, due to faulty parsing of
2414     PEM-encoded certificates has been fixed (found by Jack Lloyd)
2415
2416= Version 1.2.7 released 2013-04-13
2417Features
2418   * Ability to specify allowed ciphersuites based on the protocol version.
2419
2420Changes
2421   * Default Blowfish keysize is now 128-bits
2422   * Test suites made smaller to accommodate Raspberry Pi
2423
2424Bugfix
2425   * Fix for MPI assembly for ARM
2426   * GCM adapted to support sizes > 2^29
2427
2428= Version 1.2.6 released 2013-03-11
2429Bugfix
2430   * Fixed memory leak in ssl_free() and ssl_reset() for active session
2431   * Corrected GCM counter incrementation to use only 32-bits instead of
2432     128-bits (found by Yawning Angel)
2433   * Fixes for 64-bit compilation with MS Visual Studio
2434   * Fixed net_bind() for specified IP addresses on little endian systems
2435   * Fixed assembly code for ARM (Thumb and regular) for some compilers
2436
2437Changes
2438   * Internally split up rsa_pkcs1_encrypt(), rsa_pkcs1_decrypt(),
2439     rsa_pkcs1_sign() and rsa_pkcs1_verify() to separate PKCS#1 v1.5 and
2440     PKCS#1 v2.1 functions
2441   * Added support for custom labels when using rsa_rsaes_oaep_encrypt()
2442     or rsa_rsaes_oaep_decrypt()
2443   * Re-added handling for SSLv2 Client Hello when the define
2444     POLARSSL_SSL_SRV_SUPPORT_SSLV2_CLIENT_HELLO is set
2445   * The SSL session cache module (ssl_cache) now also retains peer_cert
2446     information (not the entire chain)
2447
2448Security
2449   * Removed further timing differences during SSL message decryption in
2450     ssl_decrypt_buf()
2451   * Removed timing differences due to bad padding from
2452     rsa_rsaes_pkcs1_v15_decrypt() and rsa_pkcs1_decrypt() for PKCS#1 v1.5
2453     operations
2454
2455= Version 1.2.5 released 2013-02-02
2456Changes
2457   * Allow enabling of dummy error_strerror() to support some use-cases
2458   * Debug messages about padding errors during SSL message decryption are
2459     disabled by default and can be enabled with POLARSSL_SSL_DEBUG_ALL
2460   * Sending of security-relevant alert messages that do not break
2461     interoperability can be switched on/off with the flag
2462     POLARSSL_SSL_ALL_ALERT_MESSAGES
2463
2464Security
2465   * Removed timing differences during SSL message decryption in
2466     ssl_decrypt_buf() due to badly formatted padding
2467
2468= Version 1.2.4 released 2013-01-25
2469Changes
2470   * More advanced SSL ciphersuite representation and moved to more dynamic
2471     SSL core
2472   * Added ssl_handshake_step() to allow single stepping the handshake process
2473
2474Bugfix
2475   * Memory leak when using RSA_PKCS_V21 operations fixed
2476   * Handle future version properly in ssl_write_certificate_request()
2477   * Correctly handle CertificateRequest message in client for <= TLS 1.1
2478     without DN list
2479
2480= Version 1.2.3 released 2012-11-26
2481Bugfix
2482   * Server not always sending correct CertificateRequest message
2483
2484= Version 1.2.2 released 2012-11-24
2485Changes
2486   * Added p_hw_data to ssl_context for context specific hardware acceleration
2487     data
2488   * During verify trust-CA is only checked for expiration and CRL presence
2489
2490Bugfixes
2491   * Fixed client authentication compatibility
2492   * Fixed dependency on POLARSSL_SHA4_C in SSL modules
2493
2494= Version 1.2.1 released 2012-11-20
2495Changes
2496   * Depth that the certificate verify callback receives is now numbered
2497     bottom-up (Peer cert depth is 0)
2498
2499Bugfixes
2500   * Fixes for MSVC6
2501   * Moved mpi_inv_mod() outside POLARSSL_GENPRIME
2502   * Allow R and A to point to same mpi in mpi_div_mpi (found by Manuel
2503     Pégourié-Gonnard)
2504   * Fixed possible segfault in mpi_shift_r() (found by Manuel
2505     Pégourié-Gonnard)
2506   * Added max length check for rsa_pkcs1_sign with PKCS#1 v2.1
2507
2508= Version 1.2.0 released 2012-10-31
2509Features
2510   * Added support for NULL cipher (POLARSSL_CIPHER_NULL_CIPHER) and weak
2511     ciphersuites (POLARSSL_ENABLE_WEAK_CIPHERSUITES). They are disabled by
2512     default!
2513   * Added support for wildcard certificates
2514   * Added support for multi-domain certificates through the X509 Subject
2515     Alternative Name extension
2516   * Added preliminary ASN.1 buffer writing support
2517   * Added preliminary X509 Certificate Request writing support
2518   * Added key_app_writer example application
2519   * Added cert_req example application
2520   * Added base Galois Counter Mode (GCM) for AES
2521   * Added TLS 1.2 support (RFC 5246)
2522   * Added GCM suites to TLS 1.2 (RFC 5288)
2523   * Added commandline error code convertor (util/strerror)
2524   * Added support for Hardware Acceleration hooking in SSL/TLS
2525   * Added OpenSSL / PolarSSL compatibility script (tests/compat.sh) and
2526     example application (programs/ssl/o_p_test) (requires OpenSSL)
2527   * Added X509 CA Path support
2528   * Added Thumb assembly optimizations
2529   * Added DEFLATE compression support as per RFC3749 (requires zlib)
2530   * Added blowfish algorithm (Generic and cipher layer)
2531   * Added PKCS#5 PBKDF2 key derivation function
2532   * Added Secure Renegotiation (RFC 5746)
2533   * Added predefined DHM groups from RFC 5114
2534   * Added simple SSL session cache implementation
2535   * Added ServerName extension parsing (SNI) at server side
2536   * Added option to add minimum accepted SSL/TLS protocol version
2537
2538Changes
2539   * Removed redundant POLARSSL_DEBUG_MSG define
2540   * AES code only check for Padlock once
2541   * Fixed const-correctness mpi_get_bit()
2542   * Documentation for mpi_lsb() and mpi_msb()
2543   * Moved out_msg to out_hdr + 32 to support hardware acceleration
2544   * Changed certificate verify behaviour to comply with RFC 6125 section 6.3
2545     to not match CN if subjectAltName extension is present (Closes ticket #56)
2546   * Cipher layer cipher_mode_t POLARSSL_MODE_CFB128 is renamed to
2547     POLARSSL_MODE_CFB, to also handle different block size CFB modes.
2548   * Removed handling for SSLv2 Client Hello (as per RFC 5246 recommendation)
2549   * Revamped session resumption handling
2550   * Generalized external private key implementation handling (like PKCS#11)
2551     in SSL/TLS
2552   * Revamped x509_verify() and the SSL f_vrfy callback implementations
2553   * Moved from unsigned long to fixed width uint32_t types throughout code
2554   * Renamed ciphersuites naming scheme to IANA reserved names
2555
2556Bugfix
2557   * Fixed handling error in mpi_cmp_mpi() on longer B values (found by
2558     Hui Dong)
2559   * Fixed potential heap corruption in x509_name allocation
2560   * Fixed single RSA test that failed on Big Endian systems (Closes ticket #54)
2561   * mpi_exp_mod() now correctly handles negative base numbers (Closes ticket
2562     #52)
2563   * Handle encryption with private key and decryption with public key as per
2564     RFC 2313
2565   * Handle empty certificate subject names
2566   * Prevent reading over buffer boundaries on X509 certificate parsing
2567   * mpi_add_abs() now correctly handles adding short numbers to long numbers
2568     with carry rollover (found by Ruslan Yushchenko)
2569   * Handle existence of OpenSSL Trust Extensions at end of X.509 DER blob
2570   * Fixed MPI assembly for SPARC64 platform
2571
2572Security
2573   * Fixed potential memory zeroization on miscrafted RSA key (found by Eloi
2574     Vanderbeken)
2575
2576= Version 1.1.8 released on 2013-10-01
2577Bugfix
2578   * Fixed potential memory leak when failing to resume a session
2579   * Fixed potential file descriptor leaks
2580
2581Security
2582   * Potential buffer-overflow for ssl_read_record() (independently found by
2583     both TrustInSoft and Paul Brodeur of Leviathan Security Group)
2584   * Potential negative value misinterpretation in load_file()
2585   * Potential heap buffer overflow on large hostname setting
2586
2587= Version 1.1.7 released on 2013-06-19
2588Changes
2589   * HAVEGE random generator disabled by default
2590
2591Bugfix
2592   * x509parse_crt() now better handles PEM error situations
2593   * ssl_parse_certificate() now calls x509parse_crt_der() directly
2594     instead of the x509parse_crt() wrapper that can also parse PEM
2595     certificates
2596   * Fixed values for 2-key Triple DES in cipher layer
2597   * ssl_write_certificate_request() can handle empty ca_chain
2598
2599Security
2600   * A possible DoS during the SSL Handshake, due to faulty parsing of
2601     PEM-encoded certificates has been fixed (found by Jack Lloyd)
2602
2603= Version 1.1.6 released on 2013-03-11
2604Bugfix
2605   * Fixed net_bind() for specified IP addresses on little endian systems
2606
2607Changes
2608   * Allow enabling of dummy error_strerror() to support some use-cases
2609   * Debug messages about padding errors during SSL message decryption are
2610     disabled by default and can be enabled with POLARSSL_SSL_DEBUG_ALL
2611
2612Security
2613   * Removed timing differences during SSL message decryption in
2614     ssl_decrypt_buf()
2615   * Removed timing differences due to bad padding from
2616     rsa_rsaes_pkcs1_v15_decrypt() and rsa_pkcs1_decrypt() for PKCS#1 v1.5
2617     operations
2618
2619= Version 1.1.5 released on 2013-01-16
2620Bugfix
2621   * Fixed MPI assembly for SPARC64 platform
2622   * Handle existence of OpenSSL Trust Extensions at end of X.509 DER blob
2623   * mpi_add_abs() now correctly handles adding short numbers to long numbers
2624     with carry rollover
2625   * Moved mpi_inv_mod() outside POLARSSL_GENPRIME
2626   * Prevent reading over buffer boundaries on X509 certificate parsing
2627   * mpi_exp_mod() now correctly handles negative base numbers (Closes ticket
2628     #52)
2629   * Fixed possible segfault in mpi_shift_r() (found by Manuel
2630     Pégourié-Gonnard)
2631   * Allow R and A to point to same mpi in mpi_div_mpi (found by Manuel
2632     Pégourié-Gonnard)
2633   * Added max length check for rsa_pkcs1_sign with PKCS#1 v2.1
2634   * Memory leak when using RSA_PKCS_V21 operations fixed
2635   * Handle encryption with private key and decryption with public key as per
2636     RFC 2313
2637   * Fixes for MSVC6
2638
2639Security
2640   * Fixed potential memory zeroization on miscrafted RSA key (found by Eloi
2641     Vanderbeken)
2642
2643= Version 1.1.4 released on 2012-05-31
2644Bugfix
2645   * Correctly handle empty SSL/TLS packets (Found by James Yonan)
2646   * Fixed potential heap corruption in x509_name allocation
2647   * Fixed single RSA test that failed on Big Endian systems (Closes ticket #54)
2648
2649= Version 1.1.3 released on 2012-04-29
2650Bugfix
2651   * Fixed random MPI generation to not generate more size than requested.
2652
2653= Version 1.1.2 released on 2012-04-26
2654Bugfix
2655   * Fixed handling error in mpi_cmp_mpi() on longer B values (found by
2656     Hui Dong)
2657
2658Security
2659   * Fixed potential memory corruption on miscrafted client messages (found by
2660     Frama-C team at CEA LIST)
2661   * Fixed generation of DHM parameters to correct length (found by Ruslan
2662     Yushchenko)
2663
2664= Version 1.1.1 released on 2012-01-23
2665Bugfix
2666   * Check for failed malloc() in ssl_set_hostname() and x509_get_entries()
2667     (Closes ticket #47, found by Hugo Leisink)
2668   * Fixed issues with Intel compiler on 64-bit systems (Closes ticket #50)
2669   * Fixed multiple compiler warnings for VS6 and armcc
2670   * Fixed bug in CTR_CRBG selftest
2671
2672= Version 1.1.0 released on 2011-12-22
2673Features
2674   * Added ssl_session_reset() to allow better multi-connection pools of
2675     SSL contexts without needing to set all non-connection-specific
2676     data and pointers again. Adapted ssl_server to use this functionality.
2677   * Added ssl_set_max_version() to allow clients to offer a lower maximum
2678     supported version to a server to help buggy server implementations.
2679     (Closes ticket #36)
2680   * Added cipher_get_cipher_mode() and cipher_get_cipher_operation()
2681     introspection functions (Closes ticket #40)
2682   * Added CTR_DRBG based on AES-256-CTR (NIST SP 800-90) random generator
2683   * Added a generic entropy accumulator that provides support for adding
2684     custom entropy sources and added some generic and platform dependent
2685     entropy sources
2686
2687Changes
2688   * Documentation for AES and Camellia in modes CTR and CFB128 clarified.
2689   * Fixed rsa_encrypt and rsa_decrypt examples to use public key for
2690     encryption and private key for decryption. (Closes ticket #34)
2691   * Inceased maximum size of ASN1 length reads to 32-bits.
2692   * Added an EXPLICIT tag number parameter to x509_get_ext()
2693   * Added a separate CRL entry extension parsing function
2694   * Separated the ASN.1 parsing code from the X.509 specific parsing code.
2695     So now there is a module that is controlled with POLARSSL_ASN1_PARSE_C.
2696   * Changed the defined key-length of DES ciphers in cipher.h to include the
2697     parity bits, to prevent mistakes in copying data. (Closes ticket #33)
2698   * Loads of minimal changes to better support WINCE as a build target
2699     (Credits go to Marco Lizza)
2700   * Added POLARSSL_MPI_WINDOW_SIZE definition to allow easier time to memory
2701     trade-off
2702   * Introduced POLARSSL_MPI_MAX_SIZE and POLARSSL_MPI_MAX_BITS for MPI size
2703     management (Closes ticket #44)
2704   * Changed the used random function pointer to more flexible format. Renamed
2705     havege_rand() to havege_random() to prevent mistakes. Lots of changes as
2706     a consequence in library code and programs
2707   * Moved all examples programs to use the new entropy and CTR_DRBG
2708   * Added permissive certificate parsing to x509parse_crt() and
2709     x509parse_crtfile(). With permissive parsing the parsing does not stop on
2710     encountering a parse-error. Beware that the meaning of return values has
2711     changed!
2712   * All error codes are now negative. Even on mermory failures and IO errors.
2713
2714Bugfix
2715   * Fixed faulty HMAC-MD2 implementation. Found by dibac. (Closes
2716     ticket #37)
2717   * Fixed a bug where the CRL parser expected an EXPLICIT ASN.1 tag
2718     before version numbers
2719   * Allowed X509 key usage parsing to accept 4 byte values instead of the
2720     standard 1 byte version sometimes used by Microsoft. (Closes ticket #38)
2721   * Fixed incorrect behaviour in case of RSASSA-PSS with a salt length
2722     smaller than the hash length. (Closes ticket #41)
2723   * If certificate serial is longer than 32 octets, serial number is now
2724     appended with '....' after first 28 octets
2725   * Improved build support for s390x and sparc64 in bignum.h
2726   * Fixed MS Visual C++ name clash with int64 in sha4.h
2727   * Corrected removal of leading "00:" in printing serial numbers in
2728     certificates and CRLs
2729
2730= Version 1.0.0 released on 2011-07-27
2731Features
2732   * Expanded cipher layer with support for CFB128 and CTR mode
2733   * Added rsa_encrypt and rsa_decrypt simple example programs.
2734
2735Changes
2736   * The generic cipher and message digest layer now have normal error
2737     codes instead of integers
2738
2739Bugfix
2740   * Undid faulty bug fix in ssl_write() when flushing old data (Ticket
2741     #18)
2742
2743= Version 0.99-pre5 released on 2011-05-26
2744Features
2745   * Added additional Cipher Block Modes to symmetric ciphers
2746     (AES CTR, Camellia CTR, XTEA CBC) including the option to
2747     enable and disable individual modes when needed
2748   * Functions requiring File System functions can now be disabled
2749     by undefining POLARSSL_FS_IO
2750   * A error_strerror function() has been added to translate between
2751     error codes and their description.
2752   * Added mpi_get_bit() and mpi_set_bit() individual bit setter/getter
2753     functions.
2754   * Added ssl_mail_client and ssl_fork_server as example programs.
2755
2756Changes
2757   * Major argument / variable rewrite. Introduced use of size_t
2758     instead of int for buffer lengths and loop variables for
2759     better unsigned / signed use. Renamed internal bigint types
2760     t_int and t_dbl to t_uint and t_udbl in the process
2761   * mpi_init() and mpi_free() now only accept a single MPI
2762     argument and do not accept variable argument lists anymore.
2763   * The error codes have been remapped and combining error codes
2764     is now done with a PLUS instead of an OR as error codes
2765     used are negative.
2766   * Changed behaviour of net_read(), ssl_fetch_input() and ssl_recv().
2767     net_recv() now returns 0 on EOF instead of
2768     POLARSSL_ERR_NET_CONN_RESET. ssl_fetch_input() returns
2769     POLARSSL_ERR_SSL_CONN_EOF on an EOF from its f_recv() function.
2770     ssl_read() returns 0 if a POLARSSL_ERR_SSL_CONN_EOF is received
2771     after the handshake.
2772   * Network functions now return POLARSSL_ERR_NET_WANT_READ or
2773     POLARSSL_ERR_NET_WANT_WRITE instead of the ambiguous
2774     POLARSSL_ERR_NET_TRY_AGAIN
2775
2776= Version 0.99-pre4 released on 2011-04-01
2777Features
2778   * Added support for PKCS#1 v2.1 encoding and thus support
2779     for the RSAES-OAEP and RSASSA-PSS operations.
2780   * Reading of Public Key files incorporated into default x509
2781     functionality as well.
2782   * Added mpi_fill_random() for centralized filling of big numbers
2783     with random data (Fixed ticket #10)
2784
2785Changes
2786   * Debug print of MPI now removes leading zero octets and
2787     displays actual bit size of the value.
2788   * x509parse_key() (and as a consequence x509parse_keyfile())
2789     does not zeroize memory in advance anymore. Use rsa_init()
2790     before parsing a key or keyfile!
2791
2792Bugfix
2793   * Debug output of MPI's now the same independent of underlying
2794     platform (32-bit / 64-bit) (Fixes ticket #19, found by Mads
2795     Kiilerich and Mihai Militaru)
2796   * Fixed bug in ssl_write() when flushing old data (Fixed ticket
2797     #18, found by Nikolay Epifanov)
2798   * Fixed proper handling of RSASSA-PSS verification with variable
2799     length salt lengths
2800
2801= Version 0.99-pre3 released on 2011-02-28
2802This release replaces version 0.99-pre2 which had possible copyright issues.
2803Features
2804   * Parsing PEM private keys encrypted with DES and AES
2805     are now supported as well (Fixes ticket #5)
2806   * Added crl_app program to allow easy reading and
2807     printing of X509 CRLs from file
2808
2809Changes
2810   * Parsing of PEM files moved to separate module (Fixes
2811     ticket #13). Also possible to remove PEM support for
2812     systems only using DER encoding
2813
2814Bugfixes
2815   * Corrected parsing of UTCTime dates before 1990 and
2816     after 1950
2817   * Support more exotic OID's when parsing certificates
2818     (found by Mads Kiilerich)
2819   * Support more exotic name representations when parsing
2820     certificates (found by Mads Kiilerich)
2821   * Replaced the expired test certificates
2822   * Do not bail out if no client certificate specified. Try
2823     to negotiate anonymous connection (Fixes ticket #12,
2824     found by Boris Krasnovskiy)
2825
2826Security fixes
2827   * Fixed a possible Man-in-the-Middle attack on the
2828     Diffie Hellman key exchange (thanks to Larry Highsmith,
2829     Subreption LLC)
2830
2831= Version 0.99-pre1 released on 2011-01-30
2832Features
2833Note: Most of these features have been donated by Fox-IT
2834   * Added Doxygen source code documentation parts
2835   * Added reading of DHM context from memory and file
2836   * Improved X509 certificate parsing to include extended
2837     certificate fields, including Key Usage
2838   * Improved certificate verification and verification
2839     against the available CRLs
2840   * Detection for DES weak keys and parity bits added
2841   * Improvements to support integration in other
2842     applications:
2843       + Added generic message digest and cipher wrapper
2844       + Improved information about current capabilities,
2845         status, objects and configuration
2846       + Added verification callback on certificate chain
2847         verification to allow external blacklisting
2848       + Additional example programs to show usage
2849   * Added support for PKCS#11 through the use of the
2850     libpkcs11-helper library
2851
2852Changes
2853   * x509parse_time_expired() checks time in addition to
2854     the existing date check
2855   * The ciphers member of ssl_context and the cipher member
2856     of ssl_session have been renamed to ciphersuites and
2857     ciphersuite respectively. This clarifies the difference
2858     with the generic cipher layer and is better naming
2859     altogether
2860
2861= Version 0.14.0 released on 2010-08-16
2862Features
2863   * Added support for SSL_EDH_RSA_AES_128_SHA and
2864     SSL_EDH_RSA_CAMELLIA_128_SHA ciphersuites
2865   * Added compile-time and run-time version information
2866   * Expanded ssl_client2 arguments for more flexibility
2867   * Added support for TLS v1.1
2868
2869Changes
2870   * Made Makefile cleaner
2871   * Removed dependency on rand() in rsa_pkcs1_encrypt().
2872     Now using random fuction provided to function and
2873     changed the prototype of rsa_pkcs1_encrypt(),
2874     rsa_init() and rsa_gen_key().
2875   * Some SSL defines were renamed in order to avoid
2876     future confusion
2877
2878Bug fixes
2879   * Fixed CMake out of source build for tests (found by
2880     kkert)
2881   * rsa_check_private() now supports PKCS1v2 keys as well
2882   * Fixed deadlock in rsa_pkcs1_encrypt() on failing random
2883     generator
2884
2885= Version 0.13.1 released on 2010-03-24
2886Bug fixes
2887   * Fixed Makefile in library that was mistakenly merged
2888   * Added missing const string fixes
2889
2890= Version 0.13.0 released on 2010-03-21
2891Features
2892   * Added option parsing for host and port selection to
2893     ssl_client2
2894   * Added support for GeneralizedTime in X509 parsing
2895   * Added cert_app program to allow easy reading and
2896     printing of X509 certificates from file or SSL
2897     connection.
2898
2899Changes
2900   * Added const correctness for main code base
2901   * X509 signature algorithm determination is now
2902     in a function to allow easy future expansion
2903   * Changed symmetric cipher functions to
2904     identical interface (returning int result values)
2905   * Changed ARC4 to use separate input/output buffer
2906   * Added reset function for HMAC context as speed-up
2907     for specific use-cases
2908
2909Bug fixes
2910   * Fixed bug resulting in failure to send the last
2911     certificate in the chain in ssl_write_certificate() and
2912     ssl_write_certificate_request() (found by fatbob)
2913   * Added small fixes for compiler warnings on a Mac
2914     (found by Frank de Brabander)
2915   * Fixed algorithmic bug in mpi_is_prime() (found by
2916     Smbat Tonoyan)
2917
2918= Version 0.12.1 released on 2009-10-04
2919Changes
2920   * Coverage test definitions now support 'depends_on'
2921     tagging system.
2922   * Tests requiring specific hashing algorithms now honor
2923     the defines.
2924
2925Bug fixes
2926   * Changed typo in #ifdef in x509parse.c (found
2927     by Eduardo)
2928
2929= Version 0.12.0 released on 2009-07-28
2930Features
2931   * Added CMake makefiles as alternative to regular Makefiles.
2932   * Added preliminary Code Coverage tests for AES, ARC4,
2933     Base64, MPI, SHA-family, MD-family, HMAC-SHA-family,
2934     Camellia, DES, 3-DES, RSA PKCS#1, XTEA, Diffie-Hellman
2935     and X509parse.
2936
2937Changes
2938   * Error codes are not (necessarily) negative. Keep
2939     this is mind when checking for errors.
2940   * RSA_RAW renamed to SIG_RSA_RAW for consistency.
2941   * Fixed typo in name of POLARSSL_ERR_RSA_OUTPUT_TOO_LARGE.
2942   * Changed interface for AES and Camellia setkey functions
2943     to indicate invalid key lengths.
2944
2945Bug fixes
2946   * Fixed include location of endian.h on FreeBSD (found by
2947     Gabriel)
2948   * Fixed include location of endian.h and name clash on
2949     Apples (found by Martin van Hensbergen)
2950   * Fixed HMAC-MD2 by modifying md2_starts(), so that the
2951     required HMAC ipad and opad variables are not cleared.
2952     (found by code coverage tests)
2953   * Prevented use of long long in bignum if
2954     POLARSSL_HAVE_LONGLONG not defined (found by Giles
2955     Bathgate).
2956   * Fixed incorrect handling of negative strings in
2957     mpi_read_string() (found by code coverage tests).
2958   * Fixed segfault on handling empty rsa_context in
2959     rsa_check_pubkey() and rsa_check_privkey() (found by
2960     code coverage tests).
2961   * Fixed incorrect handling of one single negative input
2962     value in mpi_add_abs() (found by code coverage tests).
2963   * Fixed incorrect handling of negative first input
2964     value in mpi_sub_abs() (found by code coverage tests).
2965   * Fixed incorrect handling of negative first input
2966     value in mpi_mod_mpi() and mpi_mod_int(). Resulting
2967     change also affects mpi_write_string() (found by code
2968     coverage tests).
2969   * Corrected is_prime() results for 0, 1 and 2 (found by
2970     code coverage tests).
2971   * Fixed Camellia and XTEA for 64-bit Windows systems.
2972
2973= Version 0.11.1 released on 2009-05-17
2974   * Fixed missing functionality for SHA-224, SHA-256, SHA384,
2975     SHA-512 in rsa_pkcs1_sign()
2976
2977= Version 0.11.0 released on 2009-05-03
2978   * Fixed a bug in mpi_gcd() so that it also works when both
2979     input numbers are even and added testcases to check
2980     (found by Pierre Habouzit).
2981   * Added support for SHA-224, SHA-256, SHA-384 and SHA-512
2982     one way hash functions with the PKCS#1 v1.5 signing and
2983     verification.
2984   * Fixed minor bug regarding mpi_gcd located within the
2985     POLARSSL_GENPRIME block.
2986   * Fixed minor memory leak in x509parse_crt() and added better
2987     handling of 'full' certificate chains (found by Mathias
2988     Olsson).
2989   * Centralized file opening and reading for x509 files into
2990     load_file()
2991   * Made definition of net_htons() endian-clean for big endian
2992     systems (Found by Gernot).
2993   * Undefining POLARSSL_HAVE_ASM now also handles prevents asm in
2994     padlock and timing code.
2995   * Fixed an off-by-one buffer allocation in ssl_set_hostname()
2996     responsible for crashes and unwanted behaviour.
2997   * Added support for Certificate Revocation List (CRL) parsing.
2998   * Added support for CRL revocation to x509parse_verify() and
2999     SSL/TLS code.
3000   * Fixed compatibility of XTEA and Camellia on a 64-bit system
3001     (found by Felix von Leitner).
3002
3003= Version 0.10.0 released on 2009-01-12
3004   * Migrated XySSL to PolarSSL
3005   * Added XTEA symmetric cipher
3006   * Added Camellia symmetric cipher
3007   * Added support for ciphersuites: SSL_RSA_CAMELLIA_128_SHA,
3008     SSL_RSA_CAMELLIA_256_SHA and SSL_EDH_RSA_CAMELLIA_256_SHA
3009   * Fixed dangerous bug that can cause a heap overflow in
3010     rsa_pkcs1_decrypt (found by Christophe Devine)
3011
3012================================================================
3013XySSL ChangeLog
3014
3015= Version 0.9 released on 2008-03-16
3016
3017    * Added support for ciphersuite: SSL_RSA_AES_128_SHA
3018    * Enabled support for large files by default in aescrypt2.c
3019    * Preliminary openssl wrapper contributed by David Barrett
3020    * Fixed a bug in ssl_write() that caused the same payload to
3021      be sent twice in non-blocking mode when send returns EAGAIN
3022    * Fixed ssl_parse_client_hello(): session id and challenge must
3023      not be swapped in the SSLv2 ClientHello (found by Greg Robson)
3024    * Added user-defined callback debug function (Krystian Kolodziej)
3025    * Before freeing a certificate, properly zero out all cert. data
3026    * Fixed the "mode" parameter so that encryption/decryption are
3027      not swapped on PadLock; also fixed compilation on older versions
3028      of gcc (bug reported by David Barrett)
3029    * Correctly handle the case in padlock_xcryptcbc() when input or
3030      ouput data is non-aligned by falling back to the software
3031      implementation, as VIA Nehemiah cannot handle non-aligned buffers
3032    * Fixed a memory leak in x509parse_crt() which was reported by Greg
3033      Robson-Garth; some x509write.c fixes by Pascal Vizeli, thanks to
3034      Matthew Page who reported several bugs
3035    * Fixed x509_get_ext() to accept some rare certificates which have
3036      an INTEGER instead of a BOOLEAN for BasicConstraints::cA.
3037    * Added support on the client side for the TLS "hostname" extension
3038      (patch contributed by David Patino)
3039    * Make x509parse_verify() return BADCERT_CN_MISMATCH when an empty
3040      string is passed as the CN (bug reported by spoofy)
3041    * Added an option to enable/disable the BN assembly code
3042    * Updated rsa_check_privkey() to verify that (D*E) = 1 % (P-1)*(Q-1)
3043    * Disabled obsolete hash functions by default (MD2, MD4); updated
3044      selftest and benchmark to not test ciphers that have been disabled
3045    * Updated x509parse_cert_info() to correctly display byte 0 of the
3046      serial number, setup correct server port in the ssl client example
3047    * Fixed a critical denial-of-service with X.509 cert. verification:
3048      peer may cause xyssl to loop indefinitely by sending a certificate
3049      for which the RSA signature check fails (bug reported by Benoit)
3050    * Added test vectors for: AES-CBC, AES-CFB, DES-CBC and 3DES-CBC,
3051      HMAC-MD5, HMAC-SHA1, HMAC-SHA-256, HMAC-SHA-384, and HMAC-SHA-512
3052    * Fixed HMAC-SHA-384 and HMAC-SHA-512 (thanks to Josh Sinykin)
3053    * Modified ssl_parse_client_key_exchange() to protect against
3054      Daniel Bleichenbacher attack on PKCS#1 v1.5 padding, as well
3055      as the Klima-Pokorny-Rosa extension of Bleichenbacher's attack
3056    * Updated rsa_gen_key() so that ctx->N is always nbits in size
3057    * Fixed assembly PPC compilation errors on Mac OS X, thanks to
3058      David Barrett and Dusan Semen
3059
3060= Version 0.8 released on 2007-10-20
3061
3062    * Modified the HMAC functions to handle keys larger
3063      than 64 bytes, thanks to Stephane Desneux and gary ng
3064    * Fixed ssl_read_record() to properly update the handshake
3065      message digests, which fixes IE6/IE7 client authentication
3066    * Cleaned up the XYSSL* #defines, suggested by Azriel Fasten
3067    * Fixed net_recv(), thanks to Lorenz Schori and Egon Kocjan
3068    * Added user-defined callbacks for handling I/O and sessions
3069    * Added lots of debugging output in the SSL/TLS functions
3070    * Added preliminary X.509 cert. writing by Pascal Vizeli
3071    * Added preliminary support for the VIA PadLock routines
3072    * Added AES-CFB mode of operation, contributed by chmike
3073    * Added an SSL/TLS stress testing program (ssl_test.c)
3074    * Updated the RSA PKCS#1 code to allow choosing between
3075      RSA_PUBLIC and RSA_PRIVATE, as suggested by David Barrett
3076    * Updated ssl_read() to skip 0-length records from OpenSSL
3077    * Fixed the make install target to comply with *BSD make
3078    * Fixed a bug in mpi_read_binary() on 64-bit platforms
3079    * mpi_is_prime() speedups, thanks to Kevin McLaughlin
3080    * Fixed a long standing memory leak in mpi_is_prime()
3081    * Replaced realloc with malloc in mpi_grow(), and set
3082      the sign of zero as positive in mpi_init() (reported
3083      by Jonathan M. McCune)
3084
3085= Version 0.7 released on 2007-07-07
3086
3087    * Added support for the MicroBlaze soft-core processor
3088    * Fixed a bug in ssl_tls.c which sometimes prevented SSL
3089      connections from being established with non-blocking I/O
3090    * Fixed a couple bugs in the VS6 and UNIX Makefiles
3091    * Fixed the "PIC register ebx clobbered in asm" bug
3092    * Added HMAC starts/update/finish support functions
3093    * Added the SHA-224, SHA-384 and SHA-512 hash functions
3094    * Fixed the net_set_*block routines, thanks to Andreas
3095    * Added a few demonstration programs: md5sum, sha1sum,
3096      dh_client, dh_server, rsa_genkey, rsa_sign, rsa_verify
3097    * Added new bignum import and export helper functions
3098    * Rewrote README.txt in program/ssl/ca to better explain
3099      how to create a test PKI
3100
3101= Version 0.6 released on 2007-04-01
3102
3103    * Ciphers used in SSL/TLS can now be disabled at compile
3104      time, to reduce the memory footprint on embedded systems
3105    * Added multiply assembly code for the TriCore and modified
3106      havege_struct for this processor, thanks to David Patiño
3107    * Added multiply assembly code for 64-bit PowerPCs,
3108      thanks to Peking University and the OSU Open Source Lab
3109    * Added experimental support of Quantum Cryptography
3110    * Added support for autoconf, contributed by Arnaud Cornet
3111    * Fixed "long long" compilation issues on IA-64 and PPC64
3112    * Fixed a bug introduced in xyssl-0.5/timing.c: hardclock
3113      was not being correctly defined on ARM and MIPS
3114
3115= Version 0.5 released on 2007-03-01
3116
3117    * Added multiply assembly code for SPARC and Alpha
3118    * Added (beta) support for non-blocking I/O operations
3119    * Implemented session resuming and client authentication
3120    * Fixed some portability issues on WinCE, MINIX 3, Plan9
3121      (thanks to Benjamin Newman), HP-UX, FreeBSD and Solaris
3122    * Improved the performance of the EDH key exchange
3123    * Fixed a bug that caused valid packets with a payload
3124      size of 16384 bytes to be rejected
3125
3126= Version 0.4 released on 2007-02-01
3127
3128    * Added support for Ephemeral Diffie-Hellman key exchange
3129    * Added multiply asm code for SSE2, ARM, PPC, MIPS and M68K
3130    * Various improvement to the modular exponentiation code
3131    * Rewrote the headers to generate the API docs with doxygen
3132    * Fixed a bug in ssl_encrypt_buf (incorrect padding was
3133      generated) and in ssl_parse_client_hello (max. client
3134      version was not properly set), thanks to Didier Rebeix
3135    * Fixed another bug in ssl_parse_client_hello: clients with
3136      cipherlists larger than 96 bytes were incorrectly rejected
3137    * Fixed a couple memory leak in x509_read.c
3138
3139= Version 0.3 released on 2007-01-01
3140
3141    * Added server-side SSLv3 and TLSv1.0 support
3142    * Multiple fixes to enhance the compatibility with g++,
3143      thanks to Xosé Antón Otero Ferreira
3144    * Fixed a bug in the CBC code, thanks to dowst; also,
3145      the bignum code is no longer dependent on long long
3146    * Updated rsa_pkcs1_sign to handle arbitrary large inputs
3147    * Updated timing.c for improved compatibility with i386
3148      and 486 processors, thanks to Arnaud Cornet
3149
3150= Version 0.2 released on 2006-12-01
3151
3152    * Updated timing.c to support ARM and MIPS arch
3153    * Updated the MPI code to support 8086 on MSVC 1.5
3154    * Added the copyright notice at the top of havege.h
3155    * Fixed a bug in sha2_hmac, thanks to newsoft/Wenfang Zhang
3156    * Fixed a bug reported by Adrian Rüegsegger in x509_read_key
3157    * Fixed a bug reported by Torsten Lauter in ssl_read_record
3158    * Fixed a bug in rsa_check_privkey that would wrongly cause
3159      valid RSA keys to be dismissed (thanks to oldwolf)
3160    * Fixed a bug in mpi_is_prime that caused some primes to fail
3161      the Miller-Rabin primality test
3162
3163    I'd also like to thank Younès Hafri for the CRUX linux port,
3164    Khalil Petit who added XySSL into pkgsrc and Arnaud Cornet
3165    who maintains the Debian package :-)
3166
3167= Version 0.1 released on 2006-11-01
3168