1 // Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.
2 // Copyright (c) 2002, Oracle and/or its affiliates. All rights reserved.
3 // Copyright 2005 Nokia. All rights reserved.
4 //
5 // Licensed under the Apache License, Version 2.0 (the "License");
6 // you may not use this file except in compliance with the License.
7 // You may obtain a copy of the License at
8 //
9 //     https://www.apache.org/licenses/LICENSE-2.0
10 //
11 // Unless required by applicable law or agreed to in writing, software
12 // distributed under the License is distributed on an "AS IS" BASIS,
13 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 // See the License for the specific language governing permissions and
15 // limitations under the License.
16 
17 #include <openssl/ssl.h>
18 
19 #include <assert.h>
20 #include <string.h>
21 
22 #include <openssl/err.h>
23 #include <openssl/md5.h>
24 #include <openssl/mem.h>
25 #include <openssl/sha.h>
26 #include <openssl/stack.h>
27 
28 #include "../crypto/internal.h"
29 #include "internal.h"
30 
31 
32 BSSL_NAMESPACE_BEGIN
33 
34 static constexpr SSL_CIPHER kCiphers[] = {
35     // The RSA ciphers
36 
37     // Cipher 0A
38     {
39         SSL3_TXT_RSA_DES_192_CBC3_SHA,
40         "TLS_RSA_WITH_3DES_EDE_CBC_SHA",
41         SSL3_CK_RSA_DES_192_CBC3_SHA,
42         SSL_kRSA,
43         SSL_aRSA_DECRYPT,
44         SSL_3DES,
45         SSL_SHA1,
46         SSL_HANDSHAKE_MAC_DEFAULT,
47     },
48 
49 
50     // New AES ciphersuites
51 
52     // Cipher 2F
53     {
54         TLS1_TXT_RSA_WITH_AES_128_SHA,
55         "TLS_RSA_WITH_AES_128_CBC_SHA",
56         TLS1_CK_RSA_WITH_AES_128_SHA,
57         SSL_kRSA,
58         SSL_aRSA_DECRYPT,
59         SSL_AES128,
60         SSL_SHA1,
61         SSL_HANDSHAKE_MAC_DEFAULT,
62     },
63 
64     // Cipher 35
65     {
66         TLS1_TXT_RSA_WITH_AES_256_SHA,
67         "TLS_RSA_WITH_AES_256_CBC_SHA",
68         TLS1_CK_RSA_WITH_AES_256_SHA,
69         SSL_kRSA,
70         SSL_aRSA_DECRYPT,
71         SSL_AES256,
72         SSL_SHA1,
73         SSL_HANDSHAKE_MAC_DEFAULT,
74     },
75 
76     // PSK cipher suites.
77 
78     // Cipher 8C
79     {
80         TLS1_TXT_PSK_WITH_AES_128_CBC_SHA,
81         "TLS_PSK_WITH_AES_128_CBC_SHA",
82         TLS1_CK_PSK_WITH_AES_128_CBC_SHA,
83         SSL_kPSK,
84         SSL_aPSK,
85         SSL_AES128,
86         SSL_SHA1,
87         SSL_HANDSHAKE_MAC_DEFAULT,
88     },
89 
90     // Cipher 8D
91     {
92         TLS1_TXT_PSK_WITH_AES_256_CBC_SHA,
93         "TLS_PSK_WITH_AES_256_CBC_SHA",
94         TLS1_CK_PSK_WITH_AES_256_CBC_SHA,
95         SSL_kPSK,
96         SSL_aPSK,
97         SSL_AES256,
98         SSL_SHA1,
99         SSL_HANDSHAKE_MAC_DEFAULT,
100     },
101 
102     // GCM ciphersuites from RFC 5288
103 
104     // Cipher 9C
105     {
106         TLS1_TXT_RSA_WITH_AES_128_GCM_SHA256,
107         "TLS_RSA_WITH_AES_128_GCM_SHA256",
108         TLS1_CK_RSA_WITH_AES_128_GCM_SHA256,
109         SSL_kRSA,
110         SSL_aRSA_DECRYPT,
111         SSL_AES128GCM,
112         SSL_AEAD,
113         SSL_HANDSHAKE_MAC_SHA256,
114     },
115 
116     // Cipher 9D
117     {
118         TLS1_TXT_RSA_WITH_AES_256_GCM_SHA384,
119         "TLS_RSA_WITH_AES_256_GCM_SHA384",
120         TLS1_CK_RSA_WITH_AES_256_GCM_SHA384,
121         SSL_kRSA,
122         SSL_aRSA_DECRYPT,
123         SSL_AES256GCM,
124         SSL_AEAD,
125         SSL_HANDSHAKE_MAC_SHA384,
126     },
127 
128     // TLS 1.3 suites.
129 
130     // Cipher 1301
131     {
132         TLS1_3_RFC_AES_128_GCM_SHA256,
133         "TLS_AES_128_GCM_SHA256",
134         TLS1_3_CK_AES_128_GCM_SHA256,
135         SSL_kGENERIC,
136         SSL_aGENERIC,
137         SSL_AES128GCM,
138         SSL_AEAD,
139         SSL_HANDSHAKE_MAC_SHA256,
140     },
141 
142     // Cipher 1302
143     {
144         TLS1_3_RFC_AES_256_GCM_SHA384,
145         "TLS_AES_256_GCM_SHA384",
146         TLS1_3_CK_AES_256_GCM_SHA384,
147         SSL_kGENERIC,
148         SSL_aGENERIC,
149         SSL_AES256GCM,
150         SSL_AEAD,
151         SSL_HANDSHAKE_MAC_SHA384,
152     },
153 
154     // Cipher 1303
155     {
156         TLS1_3_RFC_CHACHA20_POLY1305_SHA256,
157         "TLS_CHACHA20_POLY1305_SHA256",
158         TLS1_3_CK_CHACHA20_POLY1305_SHA256,
159         SSL_kGENERIC,
160         SSL_aGENERIC,
161         SSL_CHACHA20POLY1305,
162         SSL_AEAD,
163         SSL_HANDSHAKE_MAC_SHA256,
164     },
165 
166     // Cipher C009
167     {
168         TLS1_TXT_ECDHE_ECDSA_WITH_AES_128_CBC_SHA,
169         "TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA",
170         TLS1_CK_ECDHE_ECDSA_WITH_AES_128_CBC_SHA,
171         SSL_kECDHE,
172         SSL_aECDSA,
173         SSL_AES128,
174         SSL_SHA1,
175         SSL_HANDSHAKE_MAC_DEFAULT,
176     },
177 
178     // Cipher C00A
179     {
180         TLS1_TXT_ECDHE_ECDSA_WITH_AES_256_CBC_SHA,
181         "TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA",
182         TLS1_CK_ECDHE_ECDSA_WITH_AES_256_CBC_SHA,
183         SSL_kECDHE,
184         SSL_aECDSA,
185         SSL_AES256,
186         SSL_SHA1,
187         SSL_HANDSHAKE_MAC_DEFAULT,
188     },
189 
190     // Cipher C013
191     {
192         TLS1_TXT_ECDHE_RSA_WITH_AES_128_CBC_SHA,
193         "TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA",
194         TLS1_CK_ECDHE_RSA_WITH_AES_128_CBC_SHA,
195         SSL_kECDHE,
196         SSL_aRSA_SIGN,
197         SSL_AES128,
198         SSL_SHA1,
199         SSL_HANDSHAKE_MAC_DEFAULT,
200     },
201 
202     // Cipher C014
203     {
204         TLS1_TXT_ECDHE_RSA_WITH_AES_256_CBC_SHA,
205         "TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA",
206         TLS1_CK_ECDHE_RSA_WITH_AES_256_CBC_SHA,
207         SSL_kECDHE,
208         SSL_aRSA_SIGN,
209         SSL_AES256,
210         SSL_SHA1,
211         SSL_HANDSHAKE_MAC_DEFAULT,
212     },
213 
214     // Cipher C027
215     {
216         TLS1_TXT_ECDHE_RSA_WITH_AES_128_CBC_SHA256,
217         "TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256",
218         TLS1_CK_ECDHE_RSA_WITH_AES_128_CBC_SHA256,
219         SSL_kECDHE,
220         SSL_aRSA_SIGN,
221         SSL_AES128,
222         SSL_SHA256,
223         SSL_HANDSHAKE_MAC_SHA256,
224     },
225 
226     // GCM based TLS v1.2 ciphersuites from RFC 5289
227 
228     // Cipher C02B
229     {
230         TLS1_TXT_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,
231         "TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256",
232         TLS1_CK_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,
233         SSL_kECDHE,
234         SSL_aECDSA,
235         SSL_AES128GCM,
236         SSL_AEAD,
237         SSL_HANDSHAKE_MAC_SHA256,
238     },
239 
240     // Cipher C02C
241     {
242         TLS1_TXT_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,
243         "TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384",
244         TLS1_CK_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,
245         SSL_kECDHE,
246         SSL_aECDSA,
247         SSL_AES256GCM,
248         SSL_AEAD,
249         SSL_HANDSHAKE_MAC_SHA384,
250     },
251 
252     // Cipher C02F
253     {
254         TLS1_TXT_ECDHE_RSA_WITH_AES_128_GCM_SHA256,
255         "TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256",
256         TLS1_CK_ECDHE_RSA_WITH_AES_128_GCM_SHA256,
257         SSL_kECDHE,
258         SSL_aRSA_SIGN,
259         SSL_AES128GCM,
260         SSL_AEAD,
261         SSL_HANDSHAKE_MAC_SHA256,
262     },
263 
264     // Cipher C030
265     {
266         TLS1_TXT_ECDHE_RSA_WITH_AES_256_GCM_SHA384,
267         "TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384",
268         TLS1_CK_ECDHE_RSA_WITH_AES_256_GCM_SHA384,
269         SSL_kECDHE,
270         SSL_aRSA_SIGN,
271         SSL_AES256GCM,
272         SSL_AEAD,
273         SSL_HANDSHAKE_MAC_SHA384,
274     },
275 
276     // ECDHE-PSK cipher suites.
277 
278     // Cipher C035
279     {
280         TLS1_TXT_ECDHE_PSK_WITH_AES_128_CBC_SHA,
281         "TLS_ECDHE_PSK_WITH_AES_128_CBC_SHA",
282         TLS1_CK_ECDHE_PSK_WITH_AES_128_CBC_SHA,
283         SSL_kECDHE,
284         SSL_aPSK,
285         SSL_AES128,
286         SSL_SHA1,
287         SSL_HANDSHAKE_MAC_DEFAULT,
288     },
289 
290     // Cipher C036
291     {
292         TLS1_TXT_ECDHE_PSK_WITH_AES_256_CBC_SHA,
293         "TLS_ECDHE_PSK_WITH_AES_256_CBC_SHA",
294         TLS1_CK_ECDHE_PSK_WITH_AES_256_CBC_SHA,
295         SSL_kECDHE,
296         SSL_aPSK,
297         SSL_AES256,
298         SSL_SHA1,
299         SSL_HANDSHAKE_MAC_DEFAULT,
300     },
301 
302     // ChaCha20-Poly1305 cipher suites.
303 
304     // Cipher CCA8
305     {
306         TLS1_TXT_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256,
307         "TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256",
308         TLS1_CK_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256,
309         SSL_kECDHE,
310         SSL_aRSA_SIGN,
311         SSL_CHACHA20POLY1305,
312         SSL_AEAD,
313         SSL_HANDSHAKE_MAC_SHA256,
314     },
315 
316     // Cipher CCA9
317     {
318         TLS1_TXT_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256,
319         "TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256",
320         TLS1_CK_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256,
321         SSL_kECDHE,
322         SSL_aECDSA,
323         SSL_CHACHA20POLY1305,
324         SSL_AEAD,
325         SSL_HANDSHAKE_MAC_SHA256,
326     },
327 
328     // Cipher CCAB
329     {
330         TLS1_TXT_ECDHE_PSK_WITH_CHACHA20_POLY1305_SHA256,
331         "TLS_ECDHE_PSK_WITH_CHACHA20_POLY1305_SHA256",
332         TLS1_CK_ECDHE_PSK_WITH_CHACHA20_POLY1305_SHA256,
333         SSL_kECDHE,
334         SSL_aPSK,
335         SSL_CHACHA20POLY1305,
336         SSL_AEAD,
337         SSL_HANDSHAKE_MAC_SHA256,
338     },
339 
340 };
341 
AllCiphers()342 Span<const SSL_CIPHER> AllCiphers() { return kCiphers; }
343 
NumTLS13Ciphers()344 static constexpr size_t NumTLS13Ciphers() {
345   size_t num = 0;
346   for (const auto &cipher : kCiphers) {
347     if (cipher.algorithm_mkey == SSL_kGENERIC) {
348       num++;
349     }
350   }
351   return num;
352 }
353 
354 #define CIPHER_ADD 1
355 #define CIPHER_KILL 2
356 #define CIPHER_DEL 3
357 #define CIPHER_ORD 4
358 #define CIPHER_SPECIAL 5
359 
360 typedef struct cipher_order_st {
361   const SSL_CIPHER *cipher;
362   bool active;
363   bool in_group;
364   struct cipher_order_st *next, *prev;
365 } CIPHER_ORDER;
366 
367 typedef struct cipher_alias_st {
368   // name is the name of the cipher alias.
369   const char *name = nullptr;
370 
371   // The following fields are bitmasks for the corresponding fields on
372   // |SSL_CIPHER|. A cipher matches a cipher alias iff, for each bitmask, the
373   // bit corresponding to the cipher's value is set to 1. If any bitmask is
374   // all zeroes, the alias matches nothing. Use |~0u| for the default value.
375   uint32_t algorithm_mkey = ~0u;
376   uint32_t algorithm_auth = ~0u;
377   uint32_t algorithm_enc = ~0u;
378   uint32_t algorithm_mac = ~0u;
379 
380   // min_version, if non-zero, matches all ciphers which were added in that
381   // particular protocol version.
382   uint16_t min_version = 0;
383 
384   // include_deprecated, if true, means this alias includes deprecated ciphers.
385   bool include_deprecated = false;
386 } CIPHER_ALIAS;
387 
388 static const CIPHER_ALIAS kCipherAliases[] = {
389     {"ALL", ~0u, ~0u, ~0u, ~0u, 0},
390 
391     // The "COMPLEMENTOFDEFAULT" rule is omitted. It matches nothing.
392 
393     // key exchange aliases
394     // (some of those using only a single bit here combine
395     // multiple key exchange algs according to the RFCs.
396     {"kRSA", SSL_kRSA, ~0u, ~0u, ~0u, 0},
397 
398     {"kECDHE", SSL_kECDHE, ~0u, ~0u, ~0u, 0},
399     {"kEECDH", SSL_kECDHE, ~0u, ~0u, ~0u, 0},
400     {"ECDH", SSL_kECDHE, ~0u, ~0u, ~0u, 0},
401 
402     {"kPSK", SSL_kPSK, ~0u, ~0u, ~0u, 0},
403 
404     // server authentication aliases
405     {"aRSA", ~0u, SSL_aRSA_SIGN | SSL_aRSA_DECRYPT, ~0u, ~0u, 0},
406     {"aECDSA", ~0u, SSL_aECDSA, ~0u, ~0u, 0},
407     {"ECDSA", ~0u, SSL_aECDSA, ~0u, ~0u, 0},
408     {"aPSK", ~0u, SSL_aPSK, ~0u, ~0u, 0},
409 
410     // aliases combining key exchange and server authentication
411     {"ECDHE", SSL_kECDHE, ~0u, ~0u, ~0u, 0},
412     {"EECDH", SSL_kECDHE, ~0u, ~0u, ~0u, 0},
413     {"RSA", SSL_kRSA, SSL_aRSA_SIGN | SSL_aRSA_DECRYPT, ~0u, ~0u, 0},
414     {"PSK", SSL_kPSK, SSL_aPSK, ~0u, ~0u, 0},
415 
416     // symmetric encryption aliases
417     {"3DES", ~0u, ~0u, SSL_3DES, ~0u, 0, /*include_deprecated=*/true},
418     {"AES128", ~0u, ~0u, SSL_AES128 | SSL_AES128GCM, ~0u, 0,
419      /*include_deprecated=*/false},
420     {"AES256", ~0u, ~0u, SSL_AES256 | SSL_AES256GCM, ~0u, 0,
421      /*include_deprecated=*/false},
422     {"AES", ~0u, ~0u, SSL_AES, ~0u, 0},
423     {"AESGCM", ~0u, ~0u, SSL_AES128GCM | SSL_AES256GCM, ~0u, 0,
424      /*include_deprecated=*/false},
425     {"CHACHA20", ~0u, ~0u, SSL_CHACHA20POLY1305, ~0u, 0,
426      /*include_deprecated=*/false},
427 
428     // MAC aliases
429     {"SHA1", ~0u, ~0u, ~0u, SSL_SHA1, 0},
430     {"SHA", ~0u, ~0u, ~0u, SSL_SHA1, 0},
431 
432     // Legacy protocol minimum version aliases. "TLSv1" is intentionally the
433     // same as "SSLv3".
434     {"SSLv3", ~0u, ~0u, ~0u, ~0u, SSL3_VERSION},
435     {"TLSv1", ~0u, ~0u, ~0u, ~0u, SSL3_VERSION},
436     {"TLSv1.2", ~0u, ~0u, ~0u, ~0u, TLS1_2_VERSION},
437 
438     // Legacy strength classes.
439     {"HIGH", ~0u, ~0u, ~0u, ~0u, 0},
440     {"FIPS", ~0u, ~0u, ~0u, ~0u, 0},
441 
442     // Temporary no-op aliases corresponding to removed SHA-2 legacy CBC
443     // ciphers. These should be removed after 2018-05-14.
444     {"SHA256", 0, 0, 0, 0, 0},
445     {"SHA384", 0, 0, 0, 0, 0},
446 };
447 
448 static const size_t kCipherAliasesLen = OPENSSL_ARRAY_SIZE(kCipherAliases);
449 
ssl_cipher_get_evp_aead(const EVP_AEAD ** out_aead,size_t * out_mac_secret_len,size_t * out_fixed_iv_len,const SSL_CIPHER * cipher,uint16_t version)450 bool ssl_cipher_get_evp_aead(const EVP_AEAD **out_aead,
451                              size_t *out_mac_secret_len,
452                              size_t *out_fixed_iv_len, const SSL_CIPHER *cipher,
453                              uint16_t version) {
454   *out_aead = NULL;
455   *out_mac_secret_len = 0;
456   *out_fixed_iv_len = 0;
457 
458   if (cipher->algorithm_mac == SSL_AEAD) {
459     if (cipher->algorithm_enc == SSL_AES128GCM) {
460       if (version < TLS1_3_VERSION) {
461         *out_aead = EVP_aead_aes_128_gcm_tls12();
462       } else {
463         *out_aead = EVP_aead_aes_128_gcm_tls13();
464       }
465       *out_fixed_iv_len = 4;
466     } else if (cipher->algorithm_enc == SSL_AES256GCM) {
467       if (version < TLS1_3_VERSION) {
468         *out_aead = EVP_aead_aes_256_gcm_tls12();
469       } else {
470         *out_aead = EVP_aead_aes_256_gcm_tls13();
471       }
472       *out_fixed_iv_len = 4;
473     } else if (cipher->algorithm_enc == SSL_CHACHA20POLY1305) {
474       *out_aead = EVP_aead_chacha20_poly1305();
475       *out_fixed_iv_len = 12;
476     } else {
477       return false;
478     }
479 
480     // In TLS 1.3, the iv_len is equal to the AEAD nonce length whereas the code
481     // above computes the TLS 1.2 construction.
482     if (version >= TLS1_3_VERSION) {
483       *out_fixed_iv_len = EVP_AEAD_nonce_length(*out_aead);
484     }
485   } else if (cipher->algorithm_mac == SSL_SHA1) {
486     if (cipher->algorithm_enc == SSL_3DES) {
487       if (version == TLS1_VERSION) {
488         *out_aead = EVP_aead_des_ede3_cbc_sha1_tls_implicit_iv();
489         *out_fixed_iv_len = 8;
490       } else {
491         *out_aead = EVP_aead_des_ede3_cbc_sha1_tls();
492       }
493     } else if (cipher->algorithm_enc == SSL_AES128) {
494       if (version == TLS1_VERSION) {
495         *out_aead = EVP_aead_aes_128_cbc_sha1_tls_implicit_iv();
496         *out_fixed_iv_len = 16;
497       } else {
498         *out_aead = EVP_aead_aes_128_cbc_sha1_tls();
499       }
500     } else if (cipher->algorithm_enc == SSL_AES256) {
501       if (version == TLS1_VERSION) {
502         *out_aead = EVP_aead_aes_256_cbc_sha1_tls_implicit_iv();
503         *out_fixed_iv_len = 16;
504       } else {
505         *out_aead = EVP_aead_aes_256_cbc_sha1_tls();
506       }
507     } else {
508       return false;
509     }
510 
511     *out_mac_secret_len = SHA_DIGEST_LENGTH;
512   } else if (cipher->algorithm_mac == SSL_SHA256) {
513     if (cipher->algorithm_enc == SSL_AES128) {
514       *out_aead = EVP_aead_aes_128_cbc_sha256_tls();
515     } else {
516       return false;
517     }
518 
519     *out_mac_secret_len = SHA256_DIGEST_LENGTH;
520   } else {
521     return false;
522   }
523 
524   return true;
525 }
526 
ssl_get_handshake_digest(uint16_t version,const SSL_CIPHER * cipher)527 const EVP_MD *ssl_get_handshake_digest(uint16_t version,
528                                        const SSL_CIPHER *cipher) {
529   switch (cipher->algorithm_prf) {
530     case SSL_HANDSHAKE_MAC_DEFAULT:
531       return version >= TLS1_2_VERSION ? EVP_sha256() : EVP_md5_sha1();
532     case SSL_HANDSHAKE_MAC_SHA256:
533       return EVP_sha256();
534     case SSL_HANDSHAKE_MAC_SHA384:
535       return EVP_sha384();
536     default:
537       assert(0);
538       return NULL;
539   }
540 }
541 
is_cipher_list_separator(char c,bool is_strict)542 static bool is_cipher_list_separator(char c, bool is_strict) {
543   if (c == ':') {
544     return true;
545   }
546   return !is_strict && (c == ' ' || c == ';' || c == ',');
547 }
548 
549 // rule_equals returns whether the NUL-terminated string |rule| is equal to the
550 // |buf_len| bytes at |buf|.
rule_equals(const char * rule,const char * buf,size_t buf_len)551 static bool rule_equals(const char *rule, const char *buf, size_t buf_len) {
552   // |strncmp| alone only checks that |buf| is a prefix of |rule|.
553   return strncmp(rule, buf, buf_len) == 0 && rule[buf_len] == '\0';
554 }
555 
ll_append_tail(CIPHER_ORDER ** head,CIPHER_ORDER * curr,CIPHER_ORDER ** tail)556 static void ll_append_tail(CIPHER_ORDER **head, CIPHER_ORDER *curr,
557                            CIPHER_ORDER **tail) {
558   if (curr == *tail) {
559     return;
560   }
561   if (curr == *head) {
562     *head = curr->next;
563   }
564   if (curr->prev != NULL) {
565     curr->prev->next = curr->next;
566   }
567   if (curr->next != NULL) {
568     curr->next->prev = curr->prev;
569   }
570   (*tail)->next = curr;
571   curr->prev = *tail;
572   curr->next = NULL;
573   *tail = curr;
574 }
575 
ll_append_head(CIPHER_ORDER ** head,CIPHER_ORDER * curr,CIPHER_ORDER ** tail)576 static void ll_append_head(CIPHER_ORDER **head, CIPHER_ORDER *curr,
577                            CIPHER_ORDER **tail) {
578   if (curr == *head) {
579     return;
580   }
581   if (curr == *tail) {
582     *tail = curr->prev;
583   }
584   if (curr->next != NULL) {
585     curr->next->prev = curr->prev;
586   }
587   if (curr->prev != NULL) {
588     curr->prev->next = curr->next;
589   }
590   (*head)->prev = curr;
591   curr->next = *head;
592   curr->prev = NULL;
593   *head = curr;
594 }
595 
~SSLCipherPreferenceList()596 SSLCipherPreferenceList::~SSLCipherPreferenceList() {
597   OPENSSL_free(in_group_flags);
598 }
599 
Init(UniquePtr<STACK_OF (SSL_CIPHER)> ciphers_arg,Span<const bool> in_group_flags_arg)600 bool SSLCipherPreferenceList::Init(UniquePtr<STACK_OF(SSL_CIPHER)> ciphers_arg,
601                                    Span<const bool> in_group_flags_arg) {
602   if (sk_SSL_CIPHER_num(ciphers_arg.get()) != in_group_flags_arg.size()) {
603     OPENSSL_PUT_ERROR(SSL, ERR_R_INTERNAL_ERROR);
604     return false;
605   }
606 
607   Array<bool> copy;
608   if (!copy.CopyFrom(in_group_flags_arg)) {
609     return false;
610   }
611   ciphers = std::move(ciphers_arg);
612   size_t unused_len;
613   copy.Release(&in_group_flags, &unused_len);
614   return true;
615 }
616 
Init(const SSLCipherPreferenceList & other)617 bool SSLCipherPreferenceList::Init(const SSLCipherPreferenceList &other) {
618   size_t size = sk_SSL_CIPHER_num(other.ciphers.get());
619   Span<const bool> other_flags(other.in_group_flags, size);
620   UniquePtr<STACK_OF(SSL_CIPHER)> other_ciphers(
621       sk_SSL_CIPHER_dup(other.ciphers.get()));
622   if (!other_ciphers) {
623     return false;
624   }
625   return Init(std::move(other_ciphers), other_flags);
626 }
627 
Remove(const SSL_CIPHER * cipher)628 void SSLCipherPreferenceList::Remove(const SSL_CIPHER *cipher) {
629   size_t index;
630   if (!sk_SSL_CIPHER_find(ciphers.get(), &index, cipher)) {
631     return;
632   }
633   if (!in_group_flags[index] /* last element of group */ && index > 0) {
634     in_group_flags[index - 1] = false;
635   }
636   for (size_t i = index; i < sk_SSL_CIPHER_num(ciphers.get()) - 1; ++i) {
637     in_group_flags[i] = in_group_flags[i + 1];
638   }
639   sk_SSL_CIPHER_delete(ciphers.get(), index);
640 }
641 
ssl_cipher_is_deprecated(const SSL_CIPHER * cipher)642 bool ssl_cipher_is_deprecated(const SSL_CIPHER *cipher) {
643   return cipher->id == TLS1_CK_ECDHE_RSA_WITH_AES_128_CBC_SHA256 ||
644          cipher->algorithm_enc == SSL_3DES;
645 }
646 
647 // ssl_cipher_apply_rule applies the rule type |rule| to ciphers matching its
648 // parameters in the linked list from |*head_p| to |*tail_p|. It writes the new
649 // head and tail of the list to |*head_p| and |*tail_p|, respectively.
650 //
651 // - If |cipher_id| is non-zero, only that cipher is selected.
652 // - Otherwise, if |strength_bits| is non-negative, it selects ciphers
653 //   of that strength.
654 // - Otherwise, |alias| must be non-null. It selects ciphers that matches
655 //   |*alias|.
ssl_cipher_apply_rule(uint32_t cipher_id,const CIPHER_ALIAS * alias,int rule,int strength_bits,bool in_group,CIPHER_ORDER ** head_p,CIPHER_ORDER ** tail_p)656 static void ssl_cipher_apply_rule(uint32_t cipher_id, const CIPHER_ALIAS *alias,
657                                   int rule, int strength_bits, bool in_group,
658                                   CIPHER_ORDER **head_p,
659                                   CIPHER_ORDER **tail_p) {
660   CIPHER_ORDER *head, *tail, *curr, *next, *last;
661   const SSL_CIPHER *cp;
662   bool reverse = false;
663 
664   if (cipher_id == 0 && strength_bits == -1 && alias->min_version == 0 &&
665       (alias->algorithm_mkey == 0 || alias->algorithm_auth == 0 ||
666        alias->algorithm_enc == 0 || alias->algorithm_mac == 0)) {
667     // The rule matches nothing, so bail early.
668     return;
669   }
670 
671   if (rule == CIPHER_DEL) {
672     // needed to maintain sorting between currently deleted ciphers
673     reverse = true;
674   }
675 
676   head = *head_p;
677   tail = *tail_p;
678 
679   if (reverse) {
680     next = tail;
681     last = head;
682   } else {
683     next = head;
684     last = tail;
685   }
686 
687   curr = NULL;
688   for (;;) {
689     if (curr == last) {
690       break;
691     }
692 
693     curr = next;
694     if (curr == NULL) {
695       break;
696     }
697 
698     next = reverse ? curr->prev : curr->next;
699     cp = curr->cipher;
700 
701     // Selection criteria is either a specific cipher, the value of
702     // |strength_bits|, or the algorithms used.
703     if (cipher_id != 0) {
704       if (cipher_id != cp->id) {
705         continue;
706       }
707     } else if (strength_bits >= 0) {
708       if (strength_bits != SSL_CIPHER_get_bits(cp, NULL)) {
709         continue;
710       }
711     } else {
712       if (!(alias->algorithm_mkey & cp->algorithm_mkey) ||
713           !(alias->algorithm_auth & cp->algorithm_auth) ||
714           !(alias->algorithm_enc & cp->algorithm_enc) ||
715           !(alias->algorithm_mac & cp->algorithm_mac) ||
716           (alias->min_version != 0 &&
717            SSL_CIPHER_get_min_version(cp) != alias->min_version) ||
718           (!alias->include_deprecated && ssl_cipher_is_deprecated(cp))) {
719         continue;
720       }
721     }
722 
723     // add the cipher if it has not been added yet.
724     if (rule == CIPHER_ADD) {
725       // reverse == false
726       if (!curr->active) {
727         ll_append_tail(&head, curr, &tail);
728         curr->active = true;
729         curr->in_group = in_group;
730       }
731     }
732 
733     // Move the added cipher to this location
734     else if (rule == CIPHER_ORD) {
735       // reverse == false
736       if (curr->active) {
737         ll_append_tail(&head, curr, &tail);
738         curr->in_group = false;
739       }
740     } else if (rule == CIPHER_DEL) {
741       // reverse == true
742       if (curr->active) {
743         // most recently deleted ciphersuites get best positions
744         // for any future CIPHER_ADD (note that the CIPHER_DEL loop
745         // works in reverse to maintain the order)
746         ll_append_head(&head, curr, &tail);
747         curr->active = false;
748         curr->in_group = false;
749       }
750     } else if (rule == CIPHER_KILL) {
751       // reverse == false
752       if (head == curr) {
753         head = curr->next;
754       } else {
755         curr->prev->next = curr->next;
756       }
757 
758       if (tail == curr) {
759         tail = curr->prev;
760       }
761       curr->active = false;
762       if (curr->next != NULL) {
763         curr->next->prev = curr->prev;
764       }
765       if (curr->prev != NULL) {
766         curr->prev->next = curr->next;
767       }
768       curr->next = NULL;
769       curr->prev = NULL;
770     }
771   }
772 
773   *head_p = head;
774   *tail_p = tail;
775 }
776 
ssl_cipher_strength_sort(CIPHER_ORDER ** head_p,CIPHER_ORDER ** tail_p)777 static bool ssl_cipher_strength_sort(CIPHER_ORDER **head_p,
778                                      CIPHER_ORDER **tail_p) {
779   // This routine sorts the ciphers with descending strength. The sorting must
780   // keep the pre-sorted sequence, so we apply the normal sorting routine as
781   // '+' movement to the end of the list.
782   int max_strength_bits = 0;
783   CIPHER_ORDER *curr = *head_p;
784   while (curr != NULL) {
785     if (curr->active &&
786         SSL_CIPHER_get_bits(curr->cipher, NULL) > max_strength_bits) {
787       max_strength_bits = SSL_CIPHER_get_bits(curr->cipher, NULL);
788     }
789     curr = curr->next;
790   }
791 
792   Array<int> number_uses;
793   if (!number_uses.Init(max_strength_bits + 1)) {
794     return false;
795   }
796 
797   // Now find the strength_bits values actually used.
798   curr = *head_p;
799   while (curr != NULL) {
800     if (curr->active) {
801       number_uses[SSL_CIPHER_get_bits(curr->cipher, NULL)]++;
802     }
803     curr = curr->next;
804   }
805 
806   // Go through the list of used strength_bits values in descending order.
807   for (int i = max_strength_bits; i >= 0; i--) {
808     if (number_uses[i] > 0) {
809       ssl_cipher_apply_rule(/*cipher_id=*/0, /*alias=*/nullptr, CIPHER_ORD, i,
810                             false, head_p, tail_p);
811     }
812   }
813 
814   return true;
815 }
816 
ssl_cipher_process_rulestr(const char * rule_str,CIPHER_ORDER ** head_p,CIPHER_ORDER ** tail_p,bool strict)817 static bool ssl_cipher_process_rulestr(const char *rule_str,
818                                        CIPHER_ORDER **head_p,
819                                        CIPHER_ORDER **tail_p, bool strict) {
820   const char *l, *buf;
821   bool in_group = false, has_group = false;
822   size_t j, buf_len;
823   char ch;
824 
825   l = rule_str;
826   for (;;) {
827     ch = *l;
828 
829     if (ch == '\0') {
830       break;  // done
831     }
832 
833     int rule;
834     if (in_group) {
835       if (ch == ']') {
836         if (*tail_p) {
837           (*tail_p)->in_group = false;
838         }
839         in_group = false;
840         l++;
841         continue;
842       }
843 
844       if (ch == '|') {
845         rule = CIPHER_ADD;
846         l++;
847         continue;
848       } else if (!OPENSSL_isalnum(ch)) {
849         OPENSSL_PUT_ERROR(SSL, SSL_R_UNEXPECTED_OPERATOR_IN_GROUP);
850         return false;
851       } else {
852         rule = CIPHER_ADD;
853       }
854     } else if (ch == '-') {
855       rule = CIPHER_DEL;
856       l++;
857     } else if (ch == '+') {
858       rule = CIPHER_ORD;
859       l++;
860     } else if (ch == '!') {
861       rule = CIPHER_KILL;
862       l++;
863     } else if (ch == '@') {
864       rule = CIPHER_SPECIAL;
865       l++;
866     } else if (ch == '[') {
867       assert(!in_group);
868       in_group = true;
869       has_group = true;
870       l++;
871       continue;
872     } else {
873       rule = CIPHER_ADD;
874     }
875 
876     // If preference groups are enabled, the only legal operator is +.
877     // Otherwise the in_group bits will get mixed up.
878     if (has_group && rule != CIPHER_ADD) {
879       OPENSSL_PUT_ERROR(SSL, SSL_R_MIXED_SPECIAL_OPERATOR_WITH_GROUPS);
880       return false;
881     }
882 
883     if (is_cipher_list_separator(ch, strict)) {
884       l++;
885       continue;
886     }
887 
888     bool multi = false;
889     uint32_t cipher_id = 0;
890     CIPHER_ALIAS alias;
891     bool skip_rule = false;
892 
893     // When adding, exclude deprecated ciphers by default.
894     alias.include_deprecated = rule != CIPHER_ADD;
895 
896     for (;;) {
897       ch = *l;
898       buf = l;
899       buf_len = 0;
900       while (OPENSSL_isalnum(ch) || ch == '-' || ch == '.' || ch == '_') {
901         ch = *(++l);
902         buf_len++;
903       }
904 
905       if (buf_len == 0) {
906         // We hit something we cannot deal with, it is no command or separator
907         // nor alphanumeric, so we call this an error.
908         OPENSSL_PUT_ERROR(SSL, SSL_R_INVALID_COMMAND);
909         return false;
910       }
911 
912       if (rule == CIPHER_SPECIAL) {
913         break;
914       }
915 
916       // Look for a matching exact cipher. These aren't allowed in multipart
917       // rules.
918       if (!multi && ch != '+') {
919         for (j = 0; j < OPENSSL_ARRAY_SIZE(kCiphers); j++) {
920           const SSL_CIPHER *cipher = &kCiphers[j];
921           if (rule_equals(cipher->name, buf, buf_len) ||
922               rule_equals(cipher->standard_name, buf, buf_len)) {
923             cipher_id = cipher->id;
924             break;
925           }
926         }
927       }
928       if (cipher_id == 0) {
929         // If not an exact cipher, look for a matching cipher alias.
930         for (j = 0; j < kCipherAliasesLen; j++) {
931           if (rule_equals(kCipherAliases[j].name, buf, buf_len)) {
932             alias.algorithm_mkey &= kCipherAliases[j].algorithm_mkey;
933             alias.algorithm_auth &= kCipherAliases[j].algorithm_auth;
934             alias.algorithm_enc &= kCipherAliases[j].algorithm_enc;
935             alias.algorithm_mac &= kCipherAliases[j].algorithm_mac;
936 
937             // When specifying a combination of aliases, if any aliases
938             // enables deprecated ciphers, deprecated ciphers are included. This
939             // is slightly different from the bitmasks in that adding aliases
940             // can increase the set of matched ciphers. This is so that an alias
941             // like "RSA" will only specifiy AES-based RSA ciphers, but
942             // "RSA+3DES" will still specify 3DES.
943             alias.include_deprecated |= kCipherAliases[j].include_deprecated;
944 
945             if (alias.min_version != 0 &&
946                 alias.min_version != kCipherAliases[j].min_version) {
947               skip_rule = true;
948             } else {
949               alias.min_version = kCipherAliases[j].min_version;
950             }
951             break;
952           }
953         }
954         if (j == kCipherAliasesLen) {
955           skip_rule = true;
956           if (strict) {
957             OPENSSL_PUT_ERROR(SSL, SSL_R_INVALID_COMMAND);
958             return false;
959           }
960         }
961       }
962 
963       // Check for a multipart rule.
964       if (ch != '+') {
965         break;
966       }
967       l++;
968       multi = true;
969     }
970 
971     // Ok, we have the rule, now apply it.
972     if (rule == CIPHER_SPECIAL) {
973       if (buf_len != 8 || strncmp(buf, "STRENGTH", 8) != 0) {
974         OPENSSL_PUT_ERROR(SSL, SSL_R_INVALID_COMMAND);
975         return false;
976       }
977       if (!ssl_cipher_strength_sort(head_p, tail_p)) {
978         return false;
979       }
980 
981       // We do not support any "multi" options together with "@", so throw away
982       // the rest of the command, if any left, until end or ':' is found.
983       while (*l != '\0' && !is_cipher_list_separator(*l, strict)) {
984         l++;
985       }
986     } else if (!skip_rule) {
987       ssl_cipher_apply_rule(cipher_id, &alias, rule, -1, in_group, head_p,
988                             tail_p);
989     }
990   }
991 
992   if (in_group) {
993     OPENSSL_PUT_ERROR(SSL, SSL_R_INVALID_COMMAND);
994     return false;
995   }
996 
997   return true;
998 }
999 
ssl_create_cipher_list(UniquePtr<SSLCipherPreferenceList> * out_cipher_list,const bool has_aes_hw,const char * rule_str,bool strict)1000 bool ssl_create_cipher_list(UniquePtr<SSLCipherPreferenceList> *out_cipher_list,
1001                             const bool has_aes_hw, const char *rule_str,
1002                             bool strict) {
1003   // Return with error if nothing to do.
1004   if (rule_str == NULL || out_cipher_list == NULL) {
1005     return false;
1006   }
1007 
1008   // We prefer ECDHE ciphers over non-PFS ciphers. Then we prefer AEAD over
1009   // non-AEAD. The constants are masked by 0xffff to remove the vestigial 0x03
1010   // byte from SSL 2.0.
1011   static const uint16_t kAESCiphers[] = {
1012       TLS1_CK_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256 & 0xffff,
1013       TLS1_CK_ECDHE_RSA_WITH_AES_128_GCM_SHA256 & 0xffff,
1014       TLS1_CK_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384 & 0xffff,
1015       TLS1_CK_ECDHE_RSA_WITH_AES_256_GCM_SHA384 & 0xffff,
1016   };
1017   static const uint16_t kChaChaCiphers[] = {
1018       TLS1_CK_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256 & 0xffff,
1019       TLS1_CK_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256 & 0xffff,
1020       TLS1_CK_ECDHE_PSK_WITH_CHACHA20_POLY1305_SHA256 & 0xffff,
1021   };
1022   static const uint16_t kLegacyCiphers[] = {
1023       TLS1_CK_ECDHE_ECDSA_WITH_AES_128_CBC_SHA & 0xffff,
1024       TLS1_CK_ECDHE_RSA_WITH_AES_128_CBC_SHA & 0xffff,
1025       TLS1_CK_ECDHE_PSK_WITH_AES_128_CBC_SHA & 0xffff,
1026       TLS1_CK_ECDHE_ECDSA_WITH_AES_256_CBC_SHA & 0xffff,
1027       TLS1_CK_ECDHE_RSA_WITH_AES_256_CBC_SHA & 0xffff,
1028       TLS1_CK_ECDHE_PSK_WITH_AES_256_CBC_SHA & 0xffff,
1029       TLS1_CK_ECDHE_RSA_WITH_AES_128_CBC_SHA256 & 0xffff,
1030       TLS1_CK_RSA_WITH_AES_128_GCM_SHA256 & 0xffff,
1031       TLS1_CK_RSA_WITH_AES_256_GCM_SHA384 & 0xffff,
1032       TLS1_CK_RSA_WITH_AES_128_SHA & 0xffff,
1033       TLS1_CK_PSK_WITH_AES_128_CBC_SHA & 0xffff,
1034       TLS1_CK_RSA_WITH_AES_256_SHA & 0xffff,
1035       TLS1_CK_PSK_WITH_AES_256_CBC_SHA & 0xffff,
1036       SSL3_CK_RSA_DES_192_CBC3_SHA & 0xffff,
1037   };
1038 
1039   // Set up a linked list of ciphers.
1040   CIPHER_ORDER co_list[OPENSSL_ARRAY_SIZE(kAESCiphers) +
1041                        OPENSSL_ARRAY_SIZE(kChaChaCiphers) +
1042                        OPENSSL_ARRAY_SIZE(kLegacyCiphers)];
1043   for (size_t i = 0; i < OPENSSL_ARRAY_SIZE(co_list); i++) {
1044     co_list[i].next =
1045         i + 1 < OPENSSL_ARRAY_SIZE(co_list) ? &co_list[i + 1] : nullptr;
1046     co_list[i].prev = i == 0 ? nullptr : &co_list[i - 1];
1047     co_list[i].active = false;
1048     co_list[i].in_group = false;
1049   }
1050   CIPHER_ORDER *head = &co_list[0];
1051   CIPHER_ORDER *tail = &co_list[OPENSSL_ARRAY_SIZE(co_list) - 1];
1052 
1053   // Order AES ciphers vs ChaCha ciphers based on whether we have AES hardware.
1054   //
1055   // TODO(crbug.com/boringssl/29): We should also set up equipreference groups
1056   // as a server.
1057   size_t num = 0;
1058   if (has_aes_hw) {
1059     for (uint16_t id : kAESCiphers) {
1060       co_list[num++].cipher = SSL_get_cipher_by_value(id);
1061       assert(co_list[num - 1].cipher != nullptr);
1062     }
1063   }
1064   for (uint16_t id : kChaChaCiphers) {
1065     co_list[num++].cipher = SSL_get_cipher_by_value(id);
1066     assert(co_list[num - 1].cipher != nullptr);
1067   }
1068   if (!has_aes_hw) {
1069     for (uint16_t id : kAESCiphers) {
1070       co_list[num++].cipher = SSL_get_cipher_by_value(id);
1071       assert(co_list[num - 1].cipher != nullptr);
1072     }
1073   }
1074   for (uint16_t id : kLegacyCiphers) {
1075     co_list[num++].cipher = SSL_get_cipher_by_value(id);
1076     assert(co_list[num - 1].cipher != nullptr);
1077   }
1078   assert(num == OPENSSL_ARRAY_SIZE(co_list));
1079   static_assert(OPENSSL_ARRAY_SIZE(co_list) + NumTLS13Ciphers() ==
1080                     OPENSSL_ARRAY_SIZE(kCiphers),
1081                 "Not all ciphers are included in the cipher order");
1082 
1083   // If the rule_string begins with DEFAULT, apply the default rule before
1084   // using the (possibly available) additional rules.
1085   const char *rule_p = rule_str;
1086   if (strncmp(rule_str, "DEFAULT", 7) == 0) {
1087     if (!ssl_cipher_process_rulestr(SSL_DEFAULT_CIPHER_LIST, &head, &tail,
1088                                     strict)) {
1089       return false;
1090     }
1091     rule_p += 7;
1092     if (*rule_p == ':') {
1093       rule_p++;
1094     }
1095   }
1096 
1097   if (*rule_p != '\0' &&
1098       !ssl_cipher_process_rulestr(rule_p, &head, &tail, strict)) {
1099     return false;
1100   }
1101 
1102   // Allocate new "cipherstack" for the result, return with error
1103   // if we cannot get one.
1104   UniquePtr<STACK_OF(SSL_CIPHER)> cipherstack(sk_SSL_CIPHER_new_null());
1105   Array<bool> in_group_flags;
1106   if (cipherstack == nullptr ||
1107       !in_group_flags.InitForOverwrite(OPENSSL_ARRAY_SIZE(kCiphers))) {
1108     return false;
1109   }
1110 
1111   // The cipher selection for the list is done. The ciphers are added
1112   // to the resulting precedence to the STACK_OF(SSL_CIPHER).
1113   size_t num_in_group_flags = 0;
1114   for (CIPHER_ORDER *curr = head; curr != NULL; curr = curr->next) {
1115     if (curr->active) {
1116       if (!sk_SSL_CIPHER_push(cipherstack.get(), curr->cipher)) {
1117         return false;
1118       }
1119       in_group_flags[num_in_group_flags++] = curr->in_group;
1120     }
1121   }
1122   in_group_flags.Shrink(num_in_group_flags);
1123 
1124   UniquePtr<SSLCipherPreferenceList> pref_list =
1125       MakeUnique<SSLCipherPreferenceList>();
1126   if (!pref_list || !pref_list->Init(std::move(cipherstack), in_group_flags)) {
1127     return false;
1128   }
1129 
1130   *out_cipher_list = std::move(pref_list);
1131 
1132   // Configuring an empty cipher list is an error but still updates the
1133   // output.
1134   if (sk_SSL_CIPHER_num((*out_cipher_list)->ciphers.get()) == 0) {
1135     OPENSSL_PUT_ERROR(SSL, SSL_R_NO_CIPHER_MATCH);
1136     return false;
1137   }
1138 
1139   return true;
1140 }
1141 
ssl_cipher_auth_mask_for_key(const EVP_PKEY * key,bool sign_ok)1142 uint32_t ssl_cipher_auth_mask_for_key(const EVP_PKEY *key, bool sign_ok) {
1143   switch (EVP_PKEY_id(key)) {
1144     case EVP_PKEY_RSA:
1145       return sign_ok ? (SSL_aRSA_SIGN | SSL_aRSA_DECRYPT) : SSL_aRSA_DECRYPT;
1146     case EVP_PKEY_EC:
1147     case EVP_PKEY_ED25519:
1148       // Ed25519 keys in TLS 1.2 repurpose the ECDSA ciphers.
1149       return sign_ok ? SSL_aECDSA : 0;
1150     default:
1151       return 0;
1152   }
1153 }
1154 
ssl_cipher_uses_certificate_auth(const SSL_CIPHER * cipher)1155 bool ssl_cipher_uses_certificate_auth(const SSL_CIPHER *cipher) {
1156   return (cipher->algorithm_auth & SSL_aCERT) != 0;
1157 }
1158 
ssl_cipher_requires_server_key_exchange(const SSL_CIPHER * cipher)1159 bool ssl_cipher_requires_server_key_exchange(const SSL_CIPHER *cipher) {
1160   // Ephemeral Diffie-Hellman key exchanges require a ServerKeyExchange. It is
1161   // optional or omitted in all others.
1162   return (cipher->algorithm_mkey & SSL_kECDHE) != 0;
1163 }
1164 
ssl_cipher_get_record_split_len(const SSL_CIPHER * cipher)1165 size_t ssl_cipher_get_record_split_len(const SSL_CIPHER *cipher) {
1166   size_t block_size;
1167   switch (cipher->algorithm_enc) {
1168     case SSL_3DES:
1169       block_size = 8;
1170       break;
1171     case SSL_AES128:
1172     case SSL_AES256:
1173       block_size = 16;
1174       break;
1175     default:
1176       return 0;
1177   }
1178 
1179   // All supported TLS 1.0 ciphers use SHA-1.
1180   assert(cipher->algorithm_mac == SSL_SHA1);
1181   size_t ret = 1 + SHA_DIGEST_LENGTH;
1182   ret += block_size - (ret % block_size);
1183   return ret;
1184 }
1185 
1186 BSSL_NAMESPACE_END
1187 
1188 using namespace bssl;
1189 
ssl_cipher_id_cmp(const SSL_CIPHER * a,const SSL_CIPHER * b)1190 static constexpr int ssl_cipher_id_cmp(const SSL_CIPHER *a,
1191                                        const SSL_CIPHER *b) {
1192   if (a->id > b->id) {
1193     return 1;
1194   }
1195   if (a->id < b->id) {
1196     return -1;
1197   }
1198   return 0;
1199 }
1200 
ssl_cipher_id_cmp_void(const void * in_a,const void * in_b)1201 static int ssl_cipher_id_cmp_void(const void *in_a, const void *in_b) {
1202   return ssl_cipher_id_cmp(reinterpret_cast<const SSL_CIPHER *>(in_a),
1203                            reinterpret_cast<const SSL_CIPHER *>(in_b));
1204 }
1205 
1206 template <size_t N>
ssl_ciphers_sorted(const SSL_CIPHER (& ciphers)[N])1207 static constexpr bool ssl_ciphers_sorted(const SSL_CIPHER (&ciphers)[N]) {
1208   for (size_t i = 1; i < N; i++) {
1209     if (ssl_cipher_id_cmp(&ciphers[i - 1], &ciphers[i]) >= 0) {
1210       return false;
1211     }
1212   }
1213   return true;
1214 }
1215 
1216 static_assert(ssl_ciphers_sorted(kCiphers),
1217               "Ciphers are not sorted, bsearch won't work");
1218 
SSL_get_cipher_by_value(uint16_t value)1219 const SSL_CIPHER *SSL_get_cipher_by_value(uint16_t value) {
1220   SSL_CIPHER c;
1221 
1222   c.id = 0x03000000L | value;
1223   return reinterpret_cast<const SSL_CIPHER *>(
1224       bsearch(&c, kCiphers, OPENSSL_ARRAY_SIZE(kCiphers), sizeof(SSL_CIPHER),
1225               ssl_cipher_id_cmp_void));
1226 }
1227 
SSL_CIPHER_get_id(const SSL_CIPHER * cipher)1228 uint32_t SSL_CIPHER_get_id(const SSL_CIPHER *cipher) { return cipher->id; }
1229 
SSL_CIPHER_get_protocol_id(const SSL_CIPHER * cipher)1230 uint16_t SSL_CIPHER_get_protocol_id(const SSL_CIPHER *cipher) {
1231   // All OpenSSL cipher IDs are prefaced with 0x03. Historically this referred
1232   // to SSLv2 vs SSLv3.
1233   assert((cipher->id & 0xff000000) == 0x03000000);
1234   return static_cast<uint16_t>(cipher->id);
1235 }
1236 
SSL_CIPHER_is_aead(const SSL_CIPHER * cipher)1237 int SSL_CIPHER_is_aead(const SSL_CIPHER *cipher) {
1238   return (cipher->algorithm_mac & SSL_AEAD) != 0;
1239 }
1240 
SSL_CIPHER_get_cipher_nid(const SSL_CIPHER * cipher)1241 int SSL_CIPHER_get_cipher_nid(const SSL_CIPHER *cipher) {
1242   switch (cipher->algorithm_enc) {
1243     case SSL_3DES:
1244       return NID_des_ede3_cbc;
1245     case SSL_AES128:
1246       return NID_aes_128_cbc;
1247     case SSL_AES256:
1248       return NID_aes_256_cbc;
1249     case SSL_AES128GCM:
1250       return NID_aes_128_gcm;
1251     case SSL_AES256GCM:
1252       return NID_aes_256_gcm;
1253     case SSL_CHACHA20POLY1305:
1254       return NID_chacha20_poly1305;
1255   }
1256   assert(0);
1257   return NID_undef;
1258 }
1259 
SSL_CIPHER_get_digest_nid(const SSL_CIPHER * cipher)1260 int SSL_CIPHER_get_digest_nid(const SSL_CIPHER *cipher) {
1261   switch (cipher->algorithm_mac) {
1262     case SSL_AEAD:
1263       return NID_undef;
1264     case SSL_SHA1:
1265       return NID_sha1;
1266     case SSL_SHA256:
1267       return NID_sha256;
1268   }
1269   assert(0);
1270   return NID_undef;
1271 }
1272 
SSL_CIPHER_get_kx_nid(const SSL_CIPHER * cipher)1273 int SSL_CIPHER_get_kx_nid(const SSL_CIPHER *cipher) {
1274   switch (cipher->algorithm_mkey) {
1275     case SSL_kRSA:
1276       return NID_kx_rsa;
1277     case SSL_kECDHE:
1278       return NID_kx_ecdhe;
1279     case SSL_kPSK:
1280       return NID_kx_psk;
1281     case SSL_kGENERIC:
1282       return NID_kx_any;
1283   }
1284   assert(0);
1285   return NID_undef;
1286 }
1287 
SSL_CIPHER_get_auth_nid(const SSL_CIPHER * cipher)1288 int SSL_CIPHER_get_auth_nid(const SSL_CIPHER *cipher) {
1289   switch (cipher->algorithm_auth) {
1290     case SSL_aRSA_DECRYPT:
1291     case SSL_aRSA_SIGN:
1292       return NID_auth_rsa;
1293     case SSL_aECDSA:
1294       return NID_auth_ecdsa;
1295     case SSL_aPSK:
1296       return NID_auth_psk;
1297     case SSL_aGENERIC:
1298       return NID_auth_any;
1299   }
1300   assert(0);
1301   return NID_undef;
1302 }
1303 
SSL_CIPHER_get_handshake_digest(const SSL_CIPHER * cipher)1304 const EVP_MD *SSL_CIPHER_get_handshake_digest(const SSL_CIPHER *cipher) {
1305   switch (cipher->algorithm_prf) {
1306     case SSL_HANDSHAKE_MAC_DEFAULT:
1307       return EVP_md5_sha1();
1308     case SSL_HANDSHAKE_MAC_SHA256:
1309       return EVP_sha256();
1310     case SSL_HANDSHAKE_MAC_SHA384:
1311       return EVP_sha384();
1312   }
1313   assert(0);
1314   return NULL;
1315 }
1316 
SSL_CIPHER_get_prf_nid(const SSL_CIPHER * cipher)1317 int SSL_CIPHER_get_prf_nid(const SSL_CIPHER *cipher) {
1318   const EVP_MD *md = SSL_CIPHER_get_handshake_digest(cipher);
1319   if (md == NULL) {
1320     return NID_undef;
1321   }
1322   return EVP_MD_nid(md);
1323 }
1324 
SSL_CIPHER_is_block_cipher(const SSL_CIPHER * cipher)1325 int SSL_CIPHER_is_block_cipher(const SSL_CIPHER *cipher) {
1326   return cipher->algorithm_mac != SSL_AEAD;
1327 }
1328 
SSL_CIPHER_get_min_version(const SSL_CIPHER * cipher)1329 uint16_t SSL_CIPHER_get_min_version(const SSL_CIPHER *cipher) {
1330   if (cipher->algorithm_mkey == SSL_kGENERIC ||
1331       cipher->algorithm_auth == SSL_aGENERIC) {
1332     return TLS1_3_VERSION;
1333   }
1334 
1335   if (cipher->algorithm_prf != SSL_HANDSHAKE_MAC_DEFAULT) {
1336     // Cipher suites before TLS 1.2 use the default PRF, while all those added
1337     // afterwards specify a particular hash.
1338     return TLS1_2_VERSION;
1339   }
1340   return SSL3_VERSION;
1341 }
1342 
SSL_CIPHER_get_max_version(const SSL_CIPHER * cipher)1343 uint16_t SSL_CIPHER_get_max_version(const SSL_CIPHER *cipher) {
1344   if (cipher->algorithm_mkey == SSL_kGENERIC ||
1345       cipher->algorithm_auth == SSL_aGENERIC) {
1346     return TLS1_3_VERSION;
1347   }
1348   return TLS1_2_VERSION;
1349 }
1350 
1351 static const char *kUnknownCipher = "(NONE)";
1352 
1353 // return the actual cipher being used
SSL_CIPHER_get_name(const SSL_CIPHER * cipher)1354 const char *SSL_CIPHER_get_name(const SSL_CIPHER *cipher) {
1355   if (cipher != NULL) {
1356     return cipher->name;
1357   }
1358 
1359   return kUnknownCipher;
1360 }
1361 
SSL_CIPHER_standard_name(const SSL_CIPHER * cipher)1362 const char *SSL_CIPHER_standard_name(const SSL_CIPHER *cipher) {
1363   return cipher->standard_name;
1364 }
1365 
SSL_CIPHER_get_kx_name(const SSL_CIPHER * cipher)1366 const char *SSL_CIPHER_get_kx_name(const SSL_CIPHER *cipher) {
1367   if (cipher == NULL) {
1368     return "";
1369   }
1370 
1371   switch (cipher->algorithm_mkey) {
1372     case SSL_kRSA:
1373       return "RSA";
1374 
1375     case SSL_kECDHE:
1376       switch (cipher->algorithm_auth) {
1377         case SSL_aECDSA:
1378           return "ECDHE_ECDSA";
1379         case SSL_aRSA_SIGN:
1380           return "ECDHE_RSA";
1381         case SSL_aPSK:
1382           return "ECDHE_PSK";
1383         default:
1384           assert(0);
1385           return "UNKNOWN";
1386       }
1387 
1388     case SSL_kPSK:
1389       assert(cipher->algorithm_auth == SSL_aPSK);
1390       return "PSK";
1391 
1392     case SSL_kGENERIC:
1393       assert(cipher->algorithm_auth == SSL_aGENERIC);
1394       return "GENERIC";
1395 
1396     default:
1397       assert(0);
1398       return "UNKNOWN";
1399   }
1400 }
1401 
SSL_CIPHER_get_bits(const SSL_CIPHER * cipher,int * out_alg_bits)1402 int SSL_CIPHER_get_bits(const SSL_CIPHER *cipher, int *out_alg_bits) {
1403   if (cipher == NULL) {
1404     return 0;
1405   }
1406 
1407   int alg_bits, strength_bits;
1408   switch (cipher->algorithm_enc) {
1409     case SSL_AES128:
1410     case SSL_AES128GCM:
1411       alg_bits = 128;
1412       strength_bits = 128;
1413       break;
1414 
1415     case SSL_AES256:
1416     case SSL_AES256GCM:
1417     case SSL_CHACHA20POLY1305:
1418       alg_bits = 256;
1419       strength_bits = 256;
1420       break;
1421 
1422     case SSL_3DES:
1423       alg_bits = 168;
1424       strength_bits = 112;
1425       break;
1426 
1427     default:
1428       assert(0);
1429       alg_bits = 0;
1430       strength_bits = 0;
1431   }
1432 
1433   if (out_alg_bits != NULL) {
1434     *out_alg_bits = alg_bits;
1435   }
1436   return strength_bits;
1437 }
1438 
SSL_CIPHER_description(const SSL_CIPHER * cipher,char * buf,int len)1439 const char *SSL_CIPHER_description(const SSL_CIPHER *cipher, char *buf,
1440                                    int len) {
1441   const char *kx, *au, *enc, *mac;
1442   uint32_t alg_mkey, alg_auth, alg_enc, alg_mac;
1443 
1444   alg_mkey = cipher->algorithm_mkey;
1445   alg_auth = cipher->algorithm_auth;
1446   alg_enc = cipher->algorithm_enc;
1447   alg_mac = cipher->algorithm_mac;
1448 
1449   switch (alg_mkey) {
1450     case SSL_kRSA:
1451       kx = "RSA";
1452       break;
1453 
1454     case SSL_kECDHE:
1455       kx = "ECDH";
1456       break;
1457 
1458     case SSL_kPSK:
1459       kx = "PSK";
1460       break;
1461 
1462     case SSL_kGENERIC:
1463       kx = "GENERIC";
1464       break;
1465 
1466     default:
1467       kx = "unknown";
1468   }
1469 
1470   switch (alg_auth) {
1471     case SSL_aRSA_DECRYPT:
1472     case SSL_aRSA_SIGN:
1473       au = "RSA";
1474       break;
1475 
1476     case SSL_aECDSA:
1477       au = "ECDSA";
1478       break;
1479 
1480     case SSL_aPSK:
1481       au = "PSK";
1482       break;
1483 
1484     case SSL_aGENERIC:
1485       au = "GENERIC";
1486       break;
1487 
1488     default:
1489       au = "unknown";
1490       break;
1491   }
1492 
1493   switch (alg_enc) {
1494     case SSL_3DES:
1495       enc = "3DES(168)";
1496       break;
1497 
1498     case SSL_AES128:
1499       enc = "AES(128)";
1500       break;
1501 
1502     case SSL_AES256:
1503       enc = "AES(256)";
1504       break;
1505 
1506     case SSL_AES128GCM:
1507       enc = "AESGCM(128)";
1508       break;
1509 
1510     case SSL_AES256GCM:
1511       enc = "AESGCM(256)";
1512       break;
1513 
1514     case SSL_CHACHA20POLY1305:
1515       enc = "ChaCha20-Poly1305";
1516       break;
1517 
1518     default:
1519       enc = "unknown";
1520       break;
1521   }
1522 
1523   switch (alg_mac) {
1524     case SSL_SHA1:
1525       mac = "SHA1";
1526       break;
1527 
1528     case SSL_SHA256:
1529       mac = "SHA256";
1530       break;
1531 
1532     case SSL_AEAD:
1533       mac = "AEAD";
1534       break;
1535 
1536     default:
1537       mac = "unknown";
1538       break;
1539   }
1540 
1541   if (buf == NULL) {
1542     len = 128;
1543     buf = (char *)OPENSSL_malloc(len);
1544     if (buf == NULL) {
1545       return NULL;
1546     }
1547   } else if (len < 128) {
1548     return "Buffer too small";
1549   }
1550 
1551   snprintf(buf, len, "%-23s Kx=%-8s Au=%-4s Enc=%-9s Mac=%-4s\n", cipher->name,
1552            kx, au, enc, mac);
1553   return buf;
1554 }
1555 
SSL_CIPHER_get_version(const SSL_CIPHER * cipher)1556 const char *SSL_CIPHER_get_version(const SSL_CIPHER *cipher) {
1557   return "TLSv1/SSLv3";
1558 }
1559 
STACK_OF(SSL_COMP)1560 STACK_OF(SSL_COMP) *SSL_COMP_get_compression_methods(void) { return NULL; }
1561 
SSL_COMP_add_compression_method(int id,COMP_METHOD * cm)1562 int SSL_COMP_add_compression_method(int id, COMP_METHOD *cm) { return 1; }
1563 
SSL_COMP_get_name(const COMP_METHOD * comp)1564 const char *SSL_COMP_get_name(const COMP_METHOD *comp) { return NULL; }
1565 
SSL_COMP_get0_name(const SSL_COMP * comp)1566 const char *SSL_COMP_get0_name(const SSL_COMP *comp) { return comp->name; }
1567 
SSL_COMP_get_id(const SSL_COMP * comp)1568 int SSL_COMP_get_id(const SSL_COMP *comp) { return comp->id; }
1569 
SSL_COMP_free_compression_methods(void)1570 void SSL_COMP_free_compression_methods(void) {}
1571 
SSL_get_all_cipher_names(const char ** out,size_t max_out)1572 size_t SSL_get_all_cipher_names(const char **out, size_t max_out) {
1573   return GetAllNames(out, max_out, Span(&kUnknownCipher, 1), &SSL_CIPHER::name,
1574                      Span(kCiphers));
1575 }
1576 
SSL_get_all_standard_cipher_names(const char ** out,size_t max_out)1577 size_t SSL_get_all_standard_cipher_names(const char **out, size_t max_out) {
1578   return GetAllNames(out, max_out, Span<const char *>(),
1579                      &SSL_CIPHER::standard_name, Span(kCiphers));
1580 }
1581