1 /**
2 * \file pk.h
3 *
4 * \brief Public Key abstraction layer
5 */
6 /*
7 * Copyright The Mbed TLS Contributors
8 * SPDX-License-Identifier: Apache-2.0
9 *
10 * Licensed under the Apache License, Version 2.0 (the "License"); you may
11 * not use this file except in compliance with the License.
12 * You may obtain a copy of the License at
13 *
14 * http://www.apache.org/licenses/LICENSE-2.0
15 *
16 * Unless required by applicable law or agreed to in writing, software
17 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
18 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
19 * See the License for the specific language governing permissions and
20 * limitations under the License.
21 */
22
23 #ifndef MBEDTLS_PK_H
24 #define MBEDTLS_PK_H
25
26 #if !defined(MBEDTLS_CONFIG_FILE)
27 #include "mbedtls/config.h"
28 #else
29 #include MBEDTLS_CONFIG_FILE
30 #endif
31
32 #include "mbedtls/md.h"
33
34 #if defined(MBEDTLS_RSA_C)
35 #include "mbedtls/rsa.h"
36 #endif
37
38 #if defined(MBEDTLS_ECP_C)
39 #include "mbedtls/ecp.h"
40 #endif
41
42 #if defined(MBEDTLS_ECDSA_C)
43 #include "mbedtls/ecdsa.h"
44 #endif
45
46 #if defined(MBEDTLS_USE_PSA_CRYPTO)
47 #include "psa/crypto.h"
48 #endif
49
50 #if ( defined(__ARMCC_VERSION) || defined(_MSC_VER) ) && \
51 !defined(inline) && !defined(__cplusplus)
52 #define inline __inline
53 #endif
54
55 /** Memory allocation failed. */
56 #define MBEDTLS_ERR_PK_ALLOC_FAILED -0x3F80
57 /** Type mismatch, eg attempt to encrypt with an ECDSA key */
58 #define MBEDTLS_ERR_PK_TYPE_MISMATCH -0x3F00
59 /** Bad input parameters to function. */
60 #define MBEDTLS_ERR_PK_BAD_INPUT_DATA -0x3E80
61 /** Read/write of file failed. */
62 #define MBEDTLS_ERR_PK_FILE_IO_ERROR -0x3E00
63 /** Unsupported key version */
64 #define MBEDTLS_ERR_PK_KEY_INVALID_VERSION -0x3D80
65 /** Invalid key tag or value. */
66 #define MBEDTLS_ERR_PK_KEY_INVALID_FORMAT -0x3D00
67 /** Key algorithm is unsupported (only RSA and EC are supported). */
68 #define MBEDTLS_ERR_PK_UNKNOWN_PK_ALG -0x3C80
69 /** Private key password can't be empty. */
70 #define MBEDTLS_ERR_PK_PASSWORD_REQUIRED -0x3C00
71 /** Given private key password does not allow for correct decryption. */
72 #define MBEDTLS_ERR_PK_PASSWORD_MISMATCH -0x3B80
73 /** The pubkey tag or value is invalid (only RSA and EC are supported). */
74 #define MBEDTLS_ERR_PK_INVALID_PUBKEY -0x3B00
75 /** The algorithm tag or value is invalid. */
76 #define MBEDTLS_ERR_PK_INVALID_ALG -0x3A80
77 /** Elliptic curve is unsupported (only NIST curves are supported). */
78 #define MBEDTLS_ERR_PK_UNKNOWN_NAMED_CURVE -0x3A00
79 /** Unavailable feature, e.g. RSA disabled for RSA key. */
80 #define MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE -0x3980
81 /** The buffer contains a valid signature followed by more data. */
82 #define MBEDTLS_ERR_PK_SIG_LEN_MISMATCH -0x3900
83
84 /* MBEDTLS_ERR_PK_HW_ACCEL_FAILED is deprecated and should not be used. */
85 /** PK hardware accelerator failed. */
86 #define MBEDTLS_ERR_PK_HW_ACCEL_FAILED -0x3880
87
88 #ifdef __cplusplus
89 extern "C" {
90 #endif
91
92 /**
93 * \brief Public key types
94 */
95 typedef enum {
96 MBEDTLS_PK_NONE=0,
97 MBEDTLS_PK_RSA,
98 MBEDTLS_PK_ECKEY,
99 MBEDTLS_PK_ECKEY_DH,
100 MBEDTLS_PK_ECDSA,
101 MBEDTLS_PK_RSA_ALT,
102 MBEDTLS_PK_RSASSA_PSS,
103 MBEDTLS_PK_OPAQUE,
104 } mbedtls_pk_type_t;
105
106 /**
107 * \brief Options for RSASSA-PSS signature verification.
108 * See \c mbedtls_rsa_rsassa_pss_verify_ext()
109 */
110 typedef struct mbedtls_pk_rsassa_pss_options
111 {
112 mbedtls_md_type_t mgf1_hash_id;
113 int expected_salt_len;
114
115 } mbedtls_pk_rsassa_pss_options;
116
117 /**
118 * \brief Maximum size of a signature made by mbedtls_pk_sign().
119 */
120 /* We need to set MBEDTLS_PK_SIGNATURE_MAX_SIZE to the maximum signature
121 * size among the supported signature types. Do it by starting at 0,
122 * then incrementally increasing to be large enough for each supported
123 * signature mechanism.
124 *
125 * The resulting value can be 0, for example if MBEDTLS_ECDH_C is enabled
126 * (which allows the pk module to be included) but neither MBEDTLS_ECDSA_C
127 * nor MBEDTLS_RSA_C nor any opaque signature mechanism (PSA or RSA_ALT).
128 */
129 #define MBEDTLS_PK_SIGNATURE_MAX_SIZE 0
130
131 #if ( defined(MBEDTLS_RSA_C) || defined(MBEDTLS_PK_RSA_ALT_SUPPORT) ) && \
132 MBEDTLS_MPI_MAX_SIZE > MBEDTLS_PK_SIGNATURE_MAX_SIZE
133 /* For RSA, the signature can be as large as the bignum module allows.
134 * For RSA_ALT, the signature size is not necessarily tied to what the
135 * bignum module can do, but in the absence of any specific setting,
136 * we use that (rsa_alt_sign_wrap in pk_wrap will check). */
137 #undef MBEDTLS_PK_SIGNATURE_MAX_SIZE
138 #define MBEDTLS_PK_SIGNATURE_MAX_SIZE MBEDTLS_MPI_MAX_SIZE
139 #endif
140
141 #if defined(MBEDTLS_ECDSA_C) && \
142 MBEDTLS_ECDSA_MAX_LEN > MBEDTLS_PK_SIGNATURE_MAX_SIZE
143 /* For ECDSA, the ecdsa module exports a constant for the maximum
144 * signature size. */
145 #undef MBEDTLS_PK_SIGNATURE_MAX_SIZE
146 #define MBEDTLS_PK_SIGNATURE_MAX_SIZE MBEDTLS_ECDSA_MAX_LEN
147 #endif
148
149 #if defined(MBEDTLS_USE_PSA_CRYPTO)
150 #if PSA_SIGNATURE_MAX_SIZE > MBEDTLS_PK_SIGNATURE_MAX_SIZE
151 /* PSA_SIGNATURE_MAX_SIZE is the maximum size of a signature made
152 * through the PSA API in the PSA representation. */
153 #undef MBEDTLS_PK_SIGNATURE_MAX_SIZE
154 #define MBEDTLS_PK_SIGNATURE_MAX_SIZE PSA_SIGNATURE_MAX_SIZE
155 #endif
156
157 #if PSA_VENDOR_ECDSA_SIGNATURE_MAX_SIZE + 11 > MBEDTLS_PK_SIGNATURE_MAX_SIZE
158 /* The Mbed TLS representation is different for ECDSA signatures:
159 * PSA uses the raw concatenation of r and s,
160 * whereas Mbed TLS uses the ASN.1 representation (SEQUENCE of two INTEGERs).
161 * Add the overhead of ASN.1: up to (1+2) + 2 * (1+2+1) for the
162 * types, lengths (represented by up to 2 bytes), and potential leading
163 * zeros of the INTEGERs and the SEQUENCE. */
164 #undef MBEDTLS_PK_SIGNATURE_MAX_SIZE
165 #define MBEDTLS_PK_SIGNATURE_MAX_SIZE ( PSA_VENDOR_ECDSA_SIGNATURE_MAX_SIZE + 11 )
166 #endif
167 #endif /* defined(MBEDTLS_USE_PSA_CRYPTO) */
168
169 /**
170 * \brief Types for interfacing with the debug module
171 */
172 typedef enum
173 {
174 MBEDTLS_PK_DEBUG_NONE = 0,
175 MBEDTLS_PK_DEBUG_MPI,
176 MBEDTLS_PK_DEBUG_ECP,
177 } mbedtls_pk_debug_type;
178
179 /**
180 * \brief Item to send to the debug module
181 */
182 typedef struct mbedtls_pk_debug_item
183 {
184 mbedtls_pk_debug_type type;
185 const char *name;
186 void *value;
187 } mbedtls_pk_debug_item;
188
189 /** Maximum number of item send for debugging, plus 1 */
190 #define MBEDTLS_PK_DEBUG_MAX_ITEMS 3
191
192 /**
193 * \brief Public key information and operations
194 */
195 typedef struct mbedtls_pk_info_t mbedtls_pk_info_t;
196
197 /**
198 * \brief Public key container
199 */
200 typedef struct mbedtls_pk_context
201 {
202 const mbedtls_pk_info_t * pk_info; /**< Public key information */
203 void * pk_ctx; /**< Underlying public key context */
204 } mbedtls_pk_context;
205
206 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
207 /**
208 * \brief Context for resuming operations
209 */
210 typedef struct
211 {
212 const mbedtls_pk_info_t * pk_info; /**< Public key information */
213 void * rs_ctx; /**< Underlying restart context */
214 } mbedtls_pk_restart_ctx;
215 #else /* MBEDTLS_ECDSA_C && MBEDTLS_ECP_RESTARTABLE */
216 /* Now we can declare functions that take a pointer to that */
217 typedef void mbedtls_pk_restart_ctx;
218 #endif /* MBEDTLS_ECDSA_C && MBEDTLS_ECP_RESTARTABLE */
219
220 #if defined(MBEDTLS_PK_RSA_ALT_SUPPORT)
221 /**
222 * \brief Types for RSA-alt abstraction
223 */
224 typedef int (*mbedtls_pk_rsa_alt_decrypt_func)( void *ctx, int mode, size_t *olen,
225 const unsigned char *input, unsigned char *output,
226 size_t output_max_len );
227 typedef int (*mbedtls_pk_rsa_alt_sign_func)( void *ctx,
228 int (*f_rng)(void *, unsigned char *, size_t), void *p_rng,
229 int mode, mbedtls_md_type_t md_alg, unsigned int hashlen,
230 const unsigned char *hash, unsigned char *sig );
231 typedef size_t (*mbedtls_pk_rsa_alt_key_len_func)( void *ctx );
232 #endif /* MBEDTLS_PK_RSA_ALT_SUPPORT */
233
234 /**
235 * \brief Return information associated with the given PK type
236 *
237 * \param pk_type PK type to search for.
238 *
239 * \return The PK info associated with the type or NULL if not found.
240 */
241 const mbedtls_pk_info_t *mbedtls_pk_info_from_type( mbedtls_pk_type_t pk_type );
242
243 /**
244 * \brief Initialize a #mbedtls_pk_context (as NONE).
245 *
246 * \param ctx The context to initialize.
247 * This must not be \c NULL.
248 */
249 void mbedtls_pk_init( mbedtls_pk_context *ctx );
250
251 /**
252 * \brief Free the components of a #mbedtls_pk_context.
253 *
254 * \param ctx The context to clear. It must have been initialized.
255 * If this is \c NULL, this function does nothing.
256 *
257 * \note For contexts that have been set up with
258 * mbedtls_pk_setup_opaque(), this does not free the underlying
259 * PSA key and you still need to call psa_destroy_key()
260 * independently if you want to destroy that key.
261 */
262 void mbedtls_pk_free( mbedtls_pk_context *ctx );
263
264 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
265 /**
266 * \brief Initialize a restart context
267 *
268 * \param ctx The context to initialize.
269 * This must not be \c NULL.
270 */
271 void mbedtls_pk_restart_init( mbedtls_pk_restart_ctx *ctx );
272
273 /**
274 * \brief Free the components of a restart context
275 *
276 * \param ctx The context to clear. It must have been initialized.
277 * If this is \c NULL, this function does nothing.
278 */
279 void mbedtls_pk_restart_free( mbedtls_pk_restart_ctx *ctx );
280 #endif /* MBEDTLS_ECDSA_C && MBEDTLS_ECP_RESTARTABLE */
281
282 /**
283 * \brief Initialize a PK context with the information given
284 * and allocates the type-specific PK subcontext.
285 *
286 * \param ctx Context to initialize. It must not have been set
287 * up yet (type #MBEDTLS_PK_NONE).
288 * \param info Information to use
289 *
290 * \return 0 on success,
291 * MBEDTLS_ERR_PK_BAD_INPUT_DATA on invalid input,
292 * MBEDTLS_ERR_PK_ALLOC_FAILED on allocation failure.
293 *
294 * \note For contexts holding an RSA-alt key, use
295 * \c mbedtls_pk_setup_rsa_alt() instead.
296 */
297 int mbedtls_pk_setup( mbedtls_pk_context *ctx, const mbedtls_pk_info_t *info );
298
299 #if defined(MBEDTLS_USE_PSA_CRYPTO)
300 /**
301 * \brief Initialize a PK context to wrap a PSA key.
302 *
303 * \note This function replaces mbedtls_pk_setup() for contexts
304 * that wrap a (possibly opaque) PSA key instead of
305 * storing and manipulating the key material directly.
306 *
307 * \param ctx The context to initialize. It must be empty (type NONE).
308 * \param key The PSA key to wrap, which must hold an ECC key pair
309 * (see notes below).
310 *
311 * \note The wrapped key must remain valid as long as the
312 * wrapping PK context is in use, that is at least between
313 * the point this function is called and the point
314 * mbedtls_pk_free() is called on this context. The wrapped
315 * key might then be independently used or destroyed.
316 *
317 * \note This function is currently only available for ECC key
318 * pairs (that is, ECC keys containing private key material).
319 * Support for other key types may be added later.
320 *
321 * \return \c 0 on success.
322 * \return #MBEDTLS_ERR_PK_BAD_INPUT_DATA on invalid input
323 * (context already used, invalid key identifier).
324 * \return #MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE if the key is not an
325 * ECC key pair.
326 * \return #MBEDTLS_ERR_PK_ALLOC_FAILED on allocation failure.
327 */
328 int mbedtls_pk_setup_opaque( mbedtls_pk_context *ctx,
329 const psa_key_id_t key );
330 #endif /* MBEDTLS_USE_PSA_CRYPTO */
331
332 #if defined(MBEDTLS_PK_RSA_ALT_SUPPORT)
333 /**
334 * \brief Initialize an RSA-alt context
335 *
336 * \param ctx Context to initialize. It must not have been set
337 * up yet (type #MBEDTLS_PK_NONE).
338 * \param key RSA key pointer
339 * \param decrypt_func Decryption function
340 * \param sign_func Signing function
341 * \param key_len_func Function returning key length in bytes
342 *
343 * \return 0 on success, or MBEDTLS_ERR_PK_BAD_INPUT_DATA if the
344 * context wasn't already initialized as RSA_ALT.
345 *
346 * \note This function replaces \c mbedtls_pk_setup() for RSA-alt.
347 */
348 int mbedtls_pk_setup_rsa_alt( mbedtls_pk_context *ctx, void * key,
349 mbedtls_pk_rsa_alt_decrypt_func decrypt_func,
350 mbedtls_pk_rsa_alt_sign_func sign_func,
351 mbedtls_pk_rsa_alt_key_len_func key_len_func );
352 #endif /* MBEDTLS_PK_RSA_ALT_SUPPORT */
353
354 /**
355 * \brief Get the size in bits of the underlying key
356 *
357 * \param ctx The context to query. It must have been initialized.
358 *
359 * \return Key size in bits, or 0 on error
360 */
361 size_t mbedtls_pk_get_bitlen( const mbedtls_pk_context *ctx );
362
363 /**
364 * \brief Get the length in bytes of the underlying key
365 *
366 * \param ctx The context to query. It must have been initialized.
367 *
368 * \return Key length in bytes, or 0 on error
369 */
mbedtls_pk_get_len(const mbedtls_pk_context * ctx)370 static inline size_t mbedtls_pk_get_len( const mbedtls_pk_context *ctx )
371 {
372 return( ( mbedtls_pk_get_bitlen( ctx ) + 7 ) / 8 );
373 }
374
375 /**
376 * \brief Tell if a context can do the operation given by type
377 *
378 * \param ctx The context to query. It must have been initialized.
379 * \param type The desired type.
380 *
381 * \return 1 if the context can do operations on the given type.
382 * \return 0 if the context cannot do the operations on the given
383 * type. This is always the case for a context that has
384 * been initialized but not set up, or that has been
385 * cleared with mbedtls_pk_free().
386 */
387 int mbedtls_pk_can_do( const mbedtls_pk_context *ctx, mbedtls_pk_type_t type );
388
389 /**
390 * \brief Verify signature (including padding if relevant).
391 *
392 * \param ctx The PK context to use. It must have been set up.
393 * \param md_alg Hash algorithm used (see notes)
394 * \param hash Hash of the message to sign
395 * \param hash_len Hash length or 0 (see notes)
396 * \param sig Signature to verify
397 * \param sig_len Signature length
398 *
399 * \return 0 on success (signature is valid),
400 * #MBEDTLS_ERR_PK_SIG_LEN_MISMATCH if there is a valid
401 * signature in sig but its length is less than \p siglen,
402 * or a specific error code.
403 *
404 * \note For RSA keys, the default padding type is PKCS#1 v1.5.
405 * Use \c mbedtls_pk_verify_ext( MBEDTLS_PK_RSASSA_PSS, ... )
406 * to verify RSASSA_PSS signatures.
407 *
408 * \note If hash_len is 0, then the length associated with md_alg
409 * is used instead, or an error returned if it is invalid.
410 *
411 * \note md_alg may be MBEDTLS_MD_NONE, only if hash_len != 0
412 */
413 int mbedtls_pk_verify( mbedtls_pk_context *ctx, mbedtls_md_type_t md_alg,
414 const unsigned char *hash, size_t hash_len,
415 const unsigned char *sig, size_t sig_len );
416
417 /**
418 * \brief Restartable version of \c mbedtls_pk_verify()
419 *
420 * \note Performs the same job as \c mbedtls_pk_verify(), but can
421 * return early and restart according to the limit set with
422 * \c mbedtls_ecp_set_max_ops() to reduce blocking for ECC
423 * operations. For RSA, same as \c mbedtls_pk_verify().
424 *
425 * \param ctx The PK context to use. It must have been set up.
426 * \param md_alg Hash algorithm used (see notes)
427 * \param hash Hash of the message to sign
428 * \param hash_len Hash length or 0 (see notes)
429 * \param sig Signature to verify
430 * \param sig_len Signature length
431 * \param rs_ctx Restart context (NULL to disable restart)
432 *
433 * \return See \c mbedtls_pk_verify(), or
434 * \return #MBEDTLS_ERR_ECP_IN_PROGRESS if maximum number of
435 * operations was reached: see \c mbedtls_ecp_set_max_ops().
436 */
437 int mbedtls_pk_verify_restartable( mbedtls_pk_context *ctx,
438 mbedtls_md_type_t md_alg,
439 const unsigned char *hash, size_t hash_len,
440 const unsigned char *sig, size_t sig_len,
441 mbedtls_pk_restart_ctx *rs_ctx );
442
443 /**
444 * \brief Verify signature, with options.
445 * (Includes verification of the padding depending on type.)
446 *
447 * \param type Signature type (inc. possible padding type) to verify
448 * \param options Pointer to type-specific options, or NULL
449 * \param ctx The PK context to use. It must have been set up.
450 * \param md_alg Hash algorithm used (see notes)
451 * \param hash Hash of the message to sign
452 * \param hash_len Hash length or 0 (see notes)
453 * \param sig Signature to verify
454 * \param sig_len Signature length
455 *
456 * \return 0 on success (signature is valid),
457 * #MBEDTLS_ERR_PK_TYPE_MISMATCH if the PK context can't be
458 * used for this type of signatures,
459 * #MBEDTLS_ERR_PK_SIG_LEN_MISMATCH if there is a valid
460 * signature in sig but its length is less than \p siglen,
461 * or a specific error code.
462 *
463 * \note If hash_len is 0, then the length associated with md_alg
464 * is used instead, or an error returned if it is invalid.
465 *
466 * \note md_alg may be MBEDTLS_MD_NONE, only if hash_len != 0
467 *
468 * \note If type is MBEDTLS_PK_RSASSA_PSS, then options must point
469 * to a mbedtls_pk_rsassa_pss_options structure,
470 * otherwise it must be NULL.
471 */
472 int mbedtls_pk_verify_ext( mbedtls_pk_type_t type, const void *options,
473 mbedtls_pk_context *ctx, mbedtls_md_type_t md_alg,
474 const unsigned char *hash, size_t hash_len,
475 const unsigned char *sig, size_t sig_len );
476
477 /**
478 * \brief Make signature, including padding if relevant.
479 *
480 * \param ctx The PK context to use. It must have been set up
481 * with a private key.
482 * \param md_alg Hash algorithm used (see notes)
483 * \param hash Hash of the message to sign
484 * \param hash_len Hash length or 0 (see notes)
485 * \param sig Place to write the signature.
486 * It must have enough room for the signature.
487 * #MBEDTLS_PK_SIGNATURE_MAX_SIZE is always enough.
488 * You may use a smaller buffer if it is large enough
489 * given the key type.
490 * \param sig_len On successful return,
491 * the number of bytes written to \p sig.
492 * \param f_rng RNG function
493 * \param p_rng RNG parameter
494 *
495 * \return 0 on success, or a specific error code.
496 *
497 * \note For RSA keys, the default padding type is PKCS#1 v1.5.
498 * There is no interface in the PK module to make RSASSA-PSS
499 * signatures yet.
500 *
501 * \note If hash_len is 0, then the length associated with md_alg
502 * is used instead, or an error returned if it is invalid.
503 *
504 * \note For RSA, md_alg may be MBEDTLS_MD_NONE if hash_len != 0.
505 * For ECDSA, md_alg may never be MBEDTLS_MD_NONE.
506 */
507 int mbedtls_pk_sign( mbedtls_pk_context *ctx, mbedtls_md_type_t md_alg,
508 const unsigned char *hash, size_t hash_len,
509 unsigned char *sig, size_t *sig_len,
510 int (*f_rng)(void *, unsigned char *, size_t), void *p_rng );
511
512 /**
513 * \brief Restartable version of \c mbedtls_pk_sign()
514 *
515 * \note Performs the same job as \c mbedtls_pk_sign(), but can
516 * return early and restart according to the limit set with
517 * \c mbedtls_ecp_set_max_ops() to reduce blocking for ECC
518 * operations. For RSA, same as \c mbedtls_pk_sign().
519 *
520 * \param ctx The PK context to use. It must have been set up
521 * with a private key.
522 * \param md_alg Hash algorithm used (see notes for mbedtls_pk_sign())
523 * \param hash Hash of the message to sign
524 * \param hash_len Hash length or 0 (see notes for mbedtls_pk_sign())
525 * \param sig Place to write the signature.
526 * It must have enough room for the signature.
527 * #MBEDTLS_PK_SIGNATURE_MAX_SIZE is always enough.
528 * You may use a smaller buffer if it is large enough
529 * given the key type.
530 * \param sig_len On successful return,
531 * the number of bytes written to \p sig.
532 * \param f_rng RNG function
533 * \param p_rng RNG parameter
534 * \param rs_ctx Restart context (NULL to disable restart)
535 *
536 * \return See \c mbedtls_pk_sign().
537 * \return #MBEDTLS_ERR_ECP_IN_PROGRESS if maximum number of
538 * operations was reached: see \c mbedtls_ecp_set_max_ops().
539 */
540 int mbedtls_pk_sign_restartable( mbedtls_pk_context *ctx,
541 mbedtls_md_type_t md_alg,
542 const unsigned char *hash, size_t hash_len,
543 unsigned char *sig, size_t *sig_len,
544 int (*f_rng)(void *, unsigned char *, size_t), void *p_rng,
545 mbedtls_pk_restart_ctx *rs_ctx );
546
547 /**
548 * \brief Decrypt message (including padding if relevant).
549 *
550 * \param ctx The PK context to use. It must have been set up
551 * with a private key.
552 * \param input Input to decrypt
553 * \param ilen Input size
554 * \param output Decrypted output
555 * \param olen Decrypted message length
556 * \param osize Size of the output buffer
557 * \param f_rng RNG function
558 * \param p_rng RNG parameter
559 *
560 * \note For RSA keys, the default padding type is PKCS#1 v1.5.
561 *
562 * \return 0 on success, or a specific error code.
563 */
564 int mbedtls_pk_decrypt( mbedtls_pk_context *ctx,
565 const unsigned char *input, size_t ilen,
566 unsigned char *output, size_t *olen, size_t osize,
567 int (*f_rng)(void *, unsigned char *, size_t), void *p_rng );
568
569 /**
570 * \brief Encrypt message (including padding if relevant).
571 *
572 * \param ctx The PK context to use. It must have been set up.
573 * \param input Message to encrypt
574 * \param ilen Message size
575 * \param output Encrypted output
576 * \param olen Encrypted output length
577 * \param osize Size of the output buffer
578 * \param f_rng RNG function
579 * \param p_rng RNG parameter
580 *
581 * \note For RSA keys, the default padding type is PKCS#1 v1.5.
582 *
583 * \return 0 on success, or a specific error code.
584 */
585 int mbedtls_pk_encrypt( mbedtls_pk_context *ctx,
586 const unsigned char *input, size_t ilen,
587 unsigned char *output, size_t *olen, size_t osize,
588 int (*f_rng)(void *, unsigned char *, size_t), void *p_rng );
589
590 /**
591 * \brief Check if a public-private pair of keys matches.
592 *
593 * \param pub Context holding a public key.
594 * \param prv Context holding a private (and public) key.
595 *
596 * \return \c 0 on success (keys were checked and match each other).
597 * \return #MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE if the keys could not
598 * be checked - in that case they may or may not match.
599 * \return #MBEDTLS_ERR_PK_BAD_INPUT_DATA if a context is invalid.
600 * \return Another non-zero value if the keys do not match.
601 */
602 int mbedtls_pk_check_pair( const mbedtls_pk_context *pub, const mbedtls_pk_context *prv );
603
604 /**
605 * \brief Export debug information
606 *
607 * \param ctx The PK context to use. It must have been initialized.
608 * \param items Place to write debug items
609 *
610 * \return 0 on success or MBEDTLS_ERR_PK_BAD_INPUT_DATA
611 */
612 int mbedtls_pk_debug( const mbedtls_pk_context *ctx, mbedtls_pk_debug_item *items );
613
614 /**
615 * \brief Access the type name
616 *
617 * \param ctx The PK context to use. It must have been initialized.
618 *
619 * \return Type name on success, or "invalid PK"
620 */
621 const char * mbedtls_pk_get_name( const mbedtls_pk_context *ctx );
622
623 /**
624 * \brief Get the key type
625 *
626 * \param ctx The PK context to use. It must have been initialized.
627 *
628 * \return Type on success.
629 * \return #MBEDTLS_PK_NONE for a context that has not been set up.
630 */
631 mbedtls_pk_type_t mbedtls_pk_get_type( const mbedtls_pk_context *ctx );
632
633 #if defined(MBEDTLS_RSA_C)
634 /**
635 * Quick access to an RSA context inside a PK context.
636 *
637 * \warning This function can only be used when the type of the context, as
638 * returned by mbedtls_pk_get_type(), is #MBEDTLS_PK_RSA.
639 * Ensuring that is the caller's responsibility.
640 * Alternatively, you can check whether this function returns NULL.
641 *
642 * \return The internal RSA context held by the PK context, or NULL.
643 */
mbedtls_pk_rsa(const mbedtls_pk_context pk)644 static inline mbedtls_rsa_context *mbedtls_pk_rsa( const mbedtls_pk_context pk )
645 {
646 switch( mbedtls_pk_get_type( &pk ) )
647 {
648 case MBEDTLS_PK_RSA:
649 return( (mbedtls_rsa_context *) (pk).pk_ctx );
650 default:
651 return( NULL );
652 }
653 }
654 #endif /* MBEDTLS_RSA_C */
655
656 #if defined(MBEDTLS_ECP_C)
657 /**
658 * Quick access to an EC context inside a PK context.
659 *
660 * \warning This function can only be used when the type of the context, as
661 * returned by mbedtls_pk_get_type(), is #MBEDTLS_PK_ECKEY,
662 * #MBEDTLS_PK_ECKEY_DH, or #MBEDTLS_PK_ECDSA.
663 * Ensuring that is the caller's responsibility.
664 * Alternatively, you can check whether this function returns NULL.
665 *
666 * \return The internal EC context held by the PK context, or NULL.
667 */
mbedtls_pk_ec(const mbedtls_pk_context pk)668 static inline mbedtls_ecp_keypair *mbedtls_pk_ec( const mbedtls_pk_context pk )
669 {
670 switch( mbedtls_pk_get_type( &pk ) )
671 {
672 case MBEDTLS_PK_ECKEY:
673 case MBEDTLS_PK_ECKEY_DH:
674 case MBEDTLS_PK_ECDSA:
675 return( (mbedtls_ecp_keypair *) (pk).pk_ctx );
676 default:
677 return( NULL );
678 }
679 }
680 #endif /* MBEDTLS_ECP_C */
681
682 #if defined(MBEDTLS_PK_PARSE_C)
683 /** \ingroup pk_module */
684 /**
685 * \brief Parse a private key in PEM or DER format
686 *
687 * \param ctx The PK context to fill. It must have been initialized
688 * but not set up.
689 * \param key Input buffer to parse.
690 * The buffer must contain the input exactly, with no
691 * extra trailing material. For PEM, the buffer must
692 * contain a null-terminated string.
693 * \param keylen Size of \b key in bytes.
694 * For PEM data, this includes the terminating null byte,
695 * so \p keylen must be equal to `strlen(key) + 1`.
696 * \param pwd Optional password for decryption.
697 * Pass \c NULL if expecting a non-encrypted key.
698 * Pass a string of \p pwdlen bytes if expecting an encrypted
699 * key; a non-encrypted key will also be accepted.
700 * The empty password is not supported.
701 * \param pwdlen Size of the password in bytes.
702 * Ignored if \p pwd is \c NULL.
703 *
704 * \note On entry, ctx must be empty, either freshly initialised
705 * with mbedtls_pk_init() or reset with mbedtls_pk_free(). If you need a
706 * specific key type, check the result with mbedtls_pk_can_do().
707 *
708 * \note The key is also checked for correctness.
709 *
710 * \return 0 if successful, or a specific PK or PEM error code
711 */
712 int mbedtls_pk_parse_key( mbedtls_pk_context *ctx,
713 const unsigned char *key, size_t keylen,
714 const unsigned char *pwd, size_t pwdlen );
715
716 /** \ingroup pk_module */
717 /**
718 * \brief Parse a public key in PEM or DER format
719 *
720 * \param ctx The PK context to fill. It must have been initialized
721 * but not set up.
722 * \param key Input buffer to parse.
723 * The buffer must contain the input exactly, with no
724 * extra trailing material. For PEM, the buffer must
725 * contain a null-terminated string.
726 * \param keylen Size of \b key in bytes.
727 * For PEM data, this includes the terminating null byte,
728 * so \p keylen must be equal to `strlen(key) + 1`.
729 *
730 * \note On entry, ctx must be empty, either freshly initialised
731 * with mbedtls_pk_init() or reset with mbedtls_pk_free(). If you need a
732 * specific key type, check the result with mbedtls_pk_can_do().
733 *
734 * \note The key is also checked for correctness.
735 *
736 * \return 0 if successful, or a specific PK or PEM error code
737 */
738 int mbedtls_pk_parse_public_key( mbedtls_pk_context *ctx,
739 const unsigned char *key, size_t keylen );
740
741 #if defined(MBEDTLS_FS_IO)
742 /** \ingroup pk_module */
743 /**
744 * \brief Load and parse a private key
745 *
746 * \param ctx The PK context to fill. It must have been initialized
747 * but not set up.
748 * \param path filename to read the private key from
749 * \param password Optional password to decrypt the file.
750 * Pass \c NULL if expecting a non-encrypted key.
751 * Pass a null-terminated string if expecting an encrypted
752 * key; a non-encrypted key will also be accepted.
753 * The empty password is not supported.
754 *
755 * \note On entry, ctx must be empty, either freshly initialised
756 * with mbedtls_pk_init() or reset with mbedtls_pk_free(). If you need a
757 * specific key type, check the result with mbedtls_pk_can_do().
758 *
759 * \note The key is also checked for correctness.
760 *
761 * \return 0 if successful, or a specific PK or PEM error code
762 */
763 int mbedtls_pk_parse_keyfile( mbedtls_pk_context *ctx,
764 const char *path, const char *password );
765
766 /** \ingroup pk_module */
767 /**
768 * \brief Load and parse a public key
769 *
770 * \param ctx The PK context to fill. It must have been initialized
771 * but not set up.
772 * \param path filename to read the public key from
773 *
774 * \note On entry, ctx must be empty, either freshly initialised
775 * with mbedtls_pk_init() or reset with mbedtls_pk_free(). If
776 * you need a specific key type, check the result with
777 * mbedtls_pk_can_do().
778 *
779 * \note The key is also checked for correctness.
780 *
781 * \return 0 if successful, or a specific PK or PEM error code
782 */
783 int mbedtls_pk_parse_public_keyfile( mbedtls_pk_context *ctx, const char *path );
784 #endif /* MBEDTLS_FS_IO */
785 #endif /* MBEDTLS_PK_PARSE_C */
786
787 #if defined(MBEDTLS_PK_WRITE_C)
788 /**
789 * \brief Write a private key to a PKCS#1 or SEC1 DER structure
790 * Note: data is written at the end of the buffer! Use the
791 * return value to determine where you should start
792 * using the buffer
793 *
794 * \param ctx PK context which must contain a valid private key.
795 * \param buf buffer to write to
796 * \param size size of the buffer
797 *
798 * \return length of data written if successful, or a specific
799 * error code
800 */
801 int mbedtls_pk_write_key_der( mbedtls_pk_context *ctx, unsigned char *buf, size_t size );
802
803 /**
804 * \brief Write a public key to a SubjectPublicKeyInfo DER structure
805 * Note: data is written at the end of the buffer! Use the
806 * return value to determine where you should start
807 * using the buffer
808 *
809 * \param ctx PK context which must contain a valid public or private key.
810 * \param buf buffer to write to
811 * \param size size of the buffer
812 *
813 * \return length of data written if successful, or a specific
814 * error code
815 */
816 int mbedtls_pk_write_pubkey_der( mbedtls_pk_context *ctx, unsigned char *buf, size_t size );
817
818 #if defined(MBEDTLS_PEM_WRITE_C)
819 /**
820 * \brief Write a public key to a PEM string
821 *
822 * \param ctx PK context which must contain a valid public or private key.
823 * \param buf Buffer to write to. The output includes a
824 * terminating null byte.
825 * \param size Size of the buffer in bytes.
826 *
827 * \return 0 if successful, or a specific error code
828 */
829 int mbedtls_pk_write_pubkey_pem( mbedtls_pk_context *ctx, unsigned char *buf, size_t size );
830
831 /**
832 * \brief Write a private key to a PKCS#1 or SEC1 PEM string
833 *
834 * \param ctx PK context which must contain a valid private key.
835 * \param buf Buffer to write to. The output includes a
836 * terminating null byte.
837 * \param size Size of the buffer in bytes.
838 *
839 * \return 0 if successful, or a specific error code
840 */
841 int mbedtls_pk_write_key_pem( mbedtls_pk_context *ctx, unsigned char *buf, size_t size );
842 #endif /* MBEDTLS_PEM_WRITE_C */
843 #endif /* MBEDTLS_PK_WRITE_C */
844
845 /*
846 * WARNING: Low-level functions. You probably do not want to use these unless
847 * you are certain you do ;)
848 */
849
850 #if defined(MBEDTLS_PK_PARSE_C)
851 /**
852 * \brief Parse a SubjectPublicKeyInfo DER structure
853 *
854 * \param p the position in the ASN.1 data
855 * \param end end of the buffer
856 * \param pk The PK context to fill. It must have been initialized
857 * but not set up.
858 *
859 * \return 0 if successful, or a specific PK error code
860 */
861 int mbedtls_pk_parse_subpubkey( unsigned char **p, const unsigned char *end,
862 mbedtls_pk_context *pk );
863 #endif /* MBEDTLS_PK_PARSE_C */
864
865 #if defined(MBEDTLS_PK_WRITE_C)
866 /**
867 * \brief Write a subjectPublicKey to ASN.1 data
868 * Note: function works backwards in data buffer
869 *
870 * \param p reference to current position pointer
871 * \param start start of the buffer (for bounds-checking)
872 * \param key PK context which must contain a valid public or private key.
873 *
874 * \return the length written or a negative error code
875 */
876 int mbedtls_pk_write_pubkey( unsigned char **p, unsigned char *start,
877 const mbedtls_pk_context *key );
878 #endif /* MBEDTLS_PK_WRITE_C */
879
880 /*
881 * Internal module functions. You probably do not want to use these unless you
882 * know you do.
883 */
884 #if defined(MBEDTLS_FS_IO)
885 int mbedtls_pk_load_file( const char *path, unsigned char **buf, size_t *n );
886 #endif
887
888 #if defined(MBEDTLS_USE_PSA_CRYPTO)
889 /**
890 * \brief Turn an EC key into an opaque one.
891 *
892 * \warning This is a temporary utility function for tests. It might
893 * change or be removed at any time without notice.
894 *
895 * \note Only ECDSA keys are supported so far. Signing with the
896 * specified hash is the only allowed use of that key.
897 *
898 * \param pk Input: the EC key to import to a PSA key.
899 * Output: a PK context wrapping that PSA key.
900 * \param key Output: a PSA key identifier.
901 * It's the caller's responsibility to call
902 * psa_destroy_key() on that key identifier after calling
903 * mbedtls_pk_free() on the PK context.
904 * \param hash_alg The hash algorithm to allow for use with that key.
905 *
906 * \return \c 0 if successful.
907 * \return An Mbed TLS error code otherwise.
908 */
909 int mbedtls_pk_wrap_as_opaque( mbedtls_pk_context *pk,
910 psa_key_id_t *key,
911 psa_algorithm_t hash_alg );
912 #endif /* MBEDTLS_USE_PSA_CRYPTO */
913
914 #ifdef __cplusplus
915 }
916 #endif
917
918 #endif /* MBEDTLS_PK_H */
919