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