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 #include "mbedtls/private_access.h"
26
27 #include "mbedtls/build_info.h"
28
29 #include "mbedtls/md.h"
30
31 #if defined(MBEDTLS_RSA_C)
32 #include "mbedtls/rsa.h"
33 #endif
34
35 #if defined(MBEDTLS_ECP_C)
36 #include "mbedtls/ecp.h"
37 #endif
38
39 #if defined(MBEDTLS_ECDSA_C)
40 #include "mbedtls/ecdsa.h"
41 #endif
42
43 #if defined(MBEDTLS_USE_PSA_CRYPTO)
44 #include "psa/crypto.h"
45 #endif
46
47 #if ( defined(__ARMCC_VERSION) || defined(_MSC_VER) ) && \
48 !defined(inline) && !defined(__cplusplus)
49 #define inline __inline
50 #endif
51
52 #define MBEDTLS_ERR_PK_ALLOC_FAILED -0x3F80 /**< Memory allocation failed. */
53 #define MBEDTLS_ERR_PK_TYPE_MISMATCH -0x3F00 /**< Type mismatch, eg attempt to encrypt with an ECDSA key */
54 #define MBEDTLS_ERR_PK_BAD_INPUT_DATA -0x3E80 /**< Bad input parameters to function. */
55 #define MBEDTLS_ERR_PK_FILE_IO_ERROR -0x3E00 /**< Read/write of file failed. */
56 #define MBEDTLS_ERR_PK_KEY_INVALID_VERSION -0x3D80 /**< Unsupported key version */
57 #define MBEDTLS_ERR_PK_KEY_INVALID_FORMAT -0x3D00 /**< Invalid key tag or value. */
58 #define MBEDTLS_ERR_PK_UNKNOWN_PK_ALG -0x3C80 /**< Key algorithm is unsupported (only RSA and EC are supported). */
59 #define MBEDTLS_ERR_PK_PASSWORD_REQUIRED -0x3C00 /**< Private key password can't be empty. */
60 #define MBEDTLS_ERR_PK_PASSWORD_MISMATCH -0x3B80 /**< Given private key password does not allow for correct decryption. */
61 #define MBEDTLS_ERR_PK_INVALID_PUBKEY -0x3B00 /**< The pubkey tag or value is invalid (only RSA and EC are supported). */
62 #define MBEDTLS_ERR_PK_INVALID_ALG -0x3A80 /**< The algorithm tag or value is invalid. */
63 #define MBEDTLS_ERR_PK_UNKNOWN_NAMED_CURVE -0x3A00 /**< Elliptic curve is unsupported (only NIST curves are supported). */
64 #define MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE -0x3980 /**< Unavailable feature, e.g. RSA disabled for RSA key. */
65 #define MBEDTLS_ERR_PK_SIG_LEN_MISMATCH -0x3900 /**< The buffer contains a valid signature followed by more data. */
66 #define MBEDTLS_ERR_PK_BUFFER_TOO_SMALL -0x3880 /**< The output buffer is too small. */
67
68 #ifdef __cplusplus
69 extern "C" {
70 #endif
71
72 /**
73 * \brief Public key types
74 */
75 typedef enum {
76 MBEDTLS_PK_NONE=0,
77 MBEDTLS_PK_RSA,
78 MBEDTLS_PK_ECKEY,
79 MBEDTLS_PK_ECKEY_DH,
80 MBEDTLS_PK_ECDSA,
81 MBEDTLS_PK_RSA_ALT,
82 MBEDTLS_PK_RSASSA_PSS,
83 MBEDTLS_PK_OPAQUE,
84 } mbedtls_pk_type_t;
85
86 /**
87 * \brief Options for RSASSA-PSS signature verification.
88 * See \c mbedtls_rsa_rsassa_pss_verify_ext()
89 */
90 typedef struct mbedtls_pk_rsassa_pss_options
91 {
92 mbedtls_md_type_t MBEDTLS_PRIVATE(mgf1_hash_id);
93 int MBEDTLS_PRIVATE(expected_salt_len);
94
95 } mbedtls_pk_rsassa_pss_options;
96
97 /**
98 * \brief Maximum size of a signature made by mbedtls_pk_sign().
99 */
100 /* We need to set MBEDTLS_PK_SIGNATURE_MAX_SIZE to the maximum signature
101 * size among the supported signature types. Do it by starting at 0,
102 * then incrementally increasing to be large enough for each supported
103 * signature mechanism.
104 *
105 * The resulting value can be 0, for example if MBEDTLS_ECDH_C is enabled
106 * (which allows the pk module to be included) but neither MBEDTLS_ECDSA_C
107 * nor MBEDTLS_RSA_C nor any opaque signature mechanism (PSA or RSA_ALT).
108 */
109 #define MBEDTLS_PK_SIGNATURE_MAX_SIZE 0
110
111 #if ( defined(MBEDTLS_RSA_C) || defined(MBEDTLS_PK_RSA_ALT_SUPPORT) ) && \
112 MBEDTLS_MPI_MAX_SIZE > MBEDTLS_PK_SIGNATURE_MAX_SIZE
113 /* For RSA, the signature can be as large as the bignum module allows.
114 * For RSA_ALT, the signature size is not necessarily tied to what the
115 * bignum module can do, but in the absence of any specific setting,
116 * we use that (rsa_alt_sign_wrap in library/pk_wrap.h will check). */
117 #undef MBEDTLS_PK_SIGNATURE_MAX_SIZE
118 #define MBEDTLS_PK_SIGNATURE_MAX_SIZE MBEDTLS_MPI_MAX_SIZE
119 #endif
120
121 #if defined(MBEDTLS_ECDSA_C) && \
122 MBEDTLS_ECDSA_MAX_LEN > MBEDTLS_PK_SIGNATURE_MAX_SIZE
123 /* For ECDSA, the ecdsa module exports a constant for the maximum
124 * signature size. */
125 #undef MBEDTLS_PK_SIGNATURE_MAX_SIZE
126 #define MBEDTLS_PK_SIGNATURE_MAX_SIZE MBEDTLS_ECDSA_MAX_LEN
127 #endif
128
129 #if defined(MBEDTLS_USE_PSA_CRYPTO)
130 #if PSA_SIGNATURE_MAX_SIZE > MBEDTLS_PK_SIGNATURE_MAX_SIZE
131 /* PSA_SIGNATURE_MAX_SIZE is the maximum size of a signature made
132 * through the PSA API in the PSA representation. */
133 #undef MBEDTLS_PK_SIGNATURE_MAX_SIZE
134 #define MBEDTLS_PK_SIGNATURE_MAX_SIZE PSA_SIGNATURE_MAX_SIZE
135 #endif
136
137 #if PSA_VENDOR_ECDSA_SIGNATURE_MAX_SIZE + 11 > MBEDTLS_PK_SIGNATURE_MAX_SIZE
138 /* The Mbed TLS representation is different for ECDSA signatures:
139 * PSA uses the raw concatenation of r and s,
140 * whereas Mbed TLS uses the ASN.1 representation (SEQUENCE of two INTEGERs).
141 * Add the overhead of ASN.1: up to (1+2) + 2 * (1+2+1) for the
142 * types, lengths (represented by up to 2 bytes), and potential leading
143 * zeros of the INTEGERs and the SEQUENCE. */
144 #undef MBEDTLS_PK_SIGNATURE_MAX_SIZE
145 #define MBEDTLS_PK_SIGNATURE_MAX_SIZE ( PSA_VENDOR_ECDSA_SIGNATURE_MAX_SIZE + 11 )
146 #endif
147 #endif /* defined(MBEDTLS_USE_PSA_CRYPTO) */
148
149 /**
150 * \brief Types for interfacing with the debug module
151 */
152 typedef enum
153 {
154 MBEDTLS_PK_DEBUG_NONE = 0,
155 MBEDTLS_PK_DEBUG_MPI,
156 MBEDTLS_PK_DEBUG_ECP,
157 } mbedtls_pk_debug_type;
158
159 /**
160 * \brief Item to send to the debug module
161 */
162 typedef struct mbedtls_pk_debug_item
163 {
164 mbedtls_pk_debug_type MBEDTLS_PRIVATE(type);
165 const char *MBEDTLS_PRIVATE(name);
166 void *MBEDTLS_PRIVATE(value);
167 } mbedtls_pk_debug_item;
168
169 /** Maximum number of item send for debugging, plus 1 */
170 #define MBEDTLS_PK_DEBUG_MAX_ITEMS 3
171
172 /**
173 * \brief Public key information and operations
174 */
175 typedef struct mbedtls_pk_info_t mbedtls_pk_info_t;
176
177 /**
178 * \brief Public key container
179 */
180 typedef struct mbedtls_pk_context
181 {
182 const mbedtls_pk_info_t * MBEDTLS_PRIVATE(pk_info); /**< Public key information */
183 void * MBEDTLS_PRIVATE(pk_ctx); /**< Underlying public key context */
184 } mbedtls_pk_context;
185
186 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
187 /**
188 * \brief Context for resuming operations
189 */
190 typedef struct
191 {
192 const mbedtls_pk_info_t * MBEDTLS_PRIVATE(pk_info); /**< Public key information */
193 void * MBEDTLS_PRIVATE(rs_ctx); /**< Underlying restart context */
194 } mbedtls_pk_restart_ctx;
195 #else /* MBEDTLS_ECDSA_C && MBEDTLS_ECP_RESTARTABLE */
196 /* Now we can declare functions that take a pointer to that */
197 typedef void mbedtls_pk_restart_ctx;
198 #endif /* MBEDTLS_ECDSA_C && MBEDTLS_ECP_RESTARTABLE */
199
200 #if defined(MBEDTLS_RSA_C)
201 /**
202 * Quick access to an RSA context inside a PK context.
203 *
204 * \warning You must make sure the PK context actually holds an RSA context
205 * before using this function!
206 */
mbedtls_pk_rsa(const mbedtls_pk_context pk)207 static inline mbedtls_rsa_context *mbedtls_pk_rsa( const mbedtls_pk_context pk )
208 {
209 return( (mbedtls_rsa_context *) (pk).MBEDTLS_PRIVATE(pk_ctx) );
210 }
211 #endif /* MBEDTLS_RSA_C */
212
213 #if defined(MBEDTLS_ECP_C)
214 /**
215 * Quick access to an EC context inside a PK context.
216 *
217 * \warning You must make sure the PK context actually holds an EC context
218 * before using this function!
219 */
mbedtls_pk_ec(const mbedtls_pk_context pk)220 static inline mbedtls_ecp_keypair *mbedtls_pk_ec( const mbedtls_pk_context pk )
221 {
222 return( (mbedtls_ecp_keypair *) (pk).MBEDTLS_PRIVATE(pk_ctx) );
223 }
224 #endif /* MBEDTLS_ECP_C */
225
226 #if defined(MBEDTLS_PK_RSA_ALT_SUPPORT)
227 /**
228 * \brief Types for RSA-alt abstraction
229 */
230 typedef int (*mbedtls_pk_rsa_alt_decrypt_func)( void *ctx, size_t *olen,
231 const unsigned char *input, unsigned char *output,
232 size_t output_max_len );
233 typedef int (*mbedtls_pk_rsa_alt_sign_func)( void *ctx,
234 int (*f_rng)(void *, unsigned char *, size_t), void *p_rng,
235 mbedtls_md_type_t md_alg, unsigned int hashlen,
236 const unsigned char *hash, unsigned char *sig );
237 typedef size_t (*mbedtls_pk_rsa_alt_key_len_func)( void *ctx );
238 #endif /* MBEDTLS_PK_RSA_ALT_SUPPORT */
239
240 /**
241 * \brief Return information associated with the given PK type
242 *
243 * \param pk_type PK type to search for.
244 *
245 * \return The PK info associated with the type or NULL if not found.
246 */
247 const mbedtls_pk_info_t *mbedtls_pk_info_from_type( mbedtls_pk_type_t pk_type );
248
249 /**
250 * \brief Initialize a #mbedtls_pk_context (as NONE).
251 *
252 * \param ctx The context to initialize.
253 * This must not be \c NULL.
254 */
255 void mbedtls_pk_init( mbedtls_pk_context *ctx );
256
257 /**
258 * \brief Free the components of a #mbedtls_pk_context.
259 *
260 * \param ctx The context to clear. It must have been initialized.
261 * If this is \c NULL, this function does nothing.
262 *
263 * \note For contexts that have been set up with
264 * mbedtls_pk_setup_opaque(), this does not free the underlying
265 * PSA key and you still need to call psa_destroy_key()
266 * independently if you want to destroy that key.
267 */
268 void mbedtls_pk_free( mbedtls_pk_context *ctx );
269
270 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
271 /**
272 * \brief Initialize a restart context
273 *
274 * \param ctx The context to initialize.
275 * This must not be \c NULL.
276 */
277 void mbedtls_pk_restart_init( mbedtls_pk_restart_ctx *ctx );
278
279 /**
280 * \brief Free the components of a restart context
281 *
282 * \param ctx The context to clear. It must have been initialized.
283 * If this is \c NULL, this function does nothing.
284 */
285 void mbedtls_pk_restart_free( mbedtls_pk_restart_ctx *ctx );
286 #endif /* MBEDTLS_ECDSA_C && MBEDTLS_ECP_RESTARTABLE */
287
288 /**
289 * \brief Initialize a PK context with the information given
290 * and allocates the type-specific PK subcontext.
291 *
292 * \param ctx Context to initialize. It must not have been set
293 * up yet (type #MBEDTLS_PK_NONE).
294 * \param info Information to use
295 *
296 * \return 0 on success,
297 * MBEDTLS_ERR_PK_BAD_INPUT_DATA on invalid input,
298 * MBEDTLS_ERR_PK_ALLOC_FAILED on allocation failure.
299 *
300 * \note For contexts holding an RSA-alt key, use
301 * \c mbedtls_pk_setup_rsa_alt() instead.
302 */
303 int mbedtls_pk_setup( mbedtls_pk_context *ctx, const mbedtls_pk_info_t *info );
304
305 #if defined(MBEDTLS_USE_PSA_CRYPTO)
306 /**
307 * \brief Initialize a PK context to wrap a PSA key.
308 *
309 * \note This function replaces mbedtls_pk_setup() for contexts
310 * that wrap a (possibly opaque) PSA key instead of
311 * storing and manipulating the key material directly.
312 *
313 * \param ctx The context to initialize. It must be empty (type NONE).
314 * \param key The PSA key to wrap, which must hold an ECC key pair
315 * (see notes below).
316 *
317 * \note The wrapped key must remain valid as long as the
318 * wrapping PK context is in use, that is at least between
319 * the point this function is called and the point
320 * mbedtls_pk_free() is called on this context. The wrapped
321 * key might then be independently used or destroyed.
322 *
323 * \note This function is currently only available for ECC key
324 * pairs (that is, ECC keys containing private key material).
325 * Support for other key types may be added later.
326 *
327 * \return \c 0 on success.
328 * \return #MBEDTLS_ERR_PK_BAD_INPUT_DATA on invalid input
329 * (context already used, invalid key identifier).
330 * \return #MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE if the key is not an
331 * ECC key pair.
332 * \return #MBEDTLS_ERR_PK_ALLOC_FAILED on allocation failure.
333 */
334 int mbedtls_pk_setup_opaque( mbedtls_pk_context *ctx,
335 const psa_key_id_t key );
336 #endif /* MBEDTLS_USE_PSA_CRYPTO */
337
338 #if defined(MBEDTLS_PK_RSA_ALT_SUPPORT)
339 /**
340 * \brief Initialize an RSA-alt context
341 *
342 * \param ctx Context to initialize. It must not have been set
343 * up yet (type #MBEDTLS_PK_NONE).
344 * \param key RSA key pointer
345 * \param decrypt_func Decryption function
346 * \param sign_func Signing function
347 * \param key_len_func Function returning key length in bytes
348 *
349 * \return 0 on success, or MBEDTLS_ERR_PK_BAD_INPUT_DATA if the
350 * context wasn't already initialized as RSA_ALT.
351 *
352 * \note This function replaces \c mbedtls_pk_setup() for RSA-alt.
353 */
354 int mbedtls_pk_setup_rsa_alt( mbedtls_pk_context *ctx, void * key,
355 mbedtls_pk_rsa_alt_decrypt_func decrypt_func,
356 mbedtls_pk_rsa_alt_sign_func sign_func,
357 mbedtls_pk_rsa_alt_key_len_func key_len_func );
358 #endif /* MBEDTLS_PK_RSA_ALT_SUPPORT */
359
360 /**
361 * \brief Get the size in bits of the underlying key
362 *
363 * \param ctx The context to query. It must have been initialized.
364 *
365 * \return Key size in bits, or 0 on error
366 */
367 size_t mbedtls_pk_get_bitlen( const mbedtls_pk_context *ctx );
368
369 /**
370 * \brief Get the length in bytes of the underlying key
371 *
372 * \param ctx The context to query. It must have been initialized.
373 *
374 * \return Key length in bytes, or 0 on error
375 */
mbedtls_pk_get_len(const mbedtls_pk_context * ctx)376 static inline size_t mbedtls_pk_get_len( const mbedtls_pk_context *ctx )
377 {
378 return( ( mbedtls_pk_get_bitlen( ctx ) + 7 ) / 8 );
379 }
380
381 /**
382 * \brief Tell if a context can do the operation given by type
383 *
384 * \param ctx The context to query. It must have been initialized.
385 * \param type The desired type.
386 *
387 * \return 1 if the context can do operations on the given type.
388 * \return 0 if the context cannot do the operations on the given
389 * type. This is always the case for a context that has
390 * been initialized but not set up, or that has been
391 * cleared with mbedtls_pk_free().
392 */
393 int mbedtls_pk_can_do( const mbedtls_pk_context *ctx, mbedtls_pk_type_t type );
394
395 /**
396 * \brief Verify signature (including padding if relevant).
397 *
398 * \param ctx The PK context to use. It must have been set up.
399 * \param md_alg Hash algorithm used.
400 * This can be #MBEDTLS_MD_NONE if the signature algorithm
401 * does not rely on a hash algorithm (non-deterministic
402 * ECDSA, RSA PKCS#1 v1.5).
403 * For PKCS#1 v1.5, if \p md_alg is #MBEDTLS_MD_NONE, then
404 * \p hash is the DigestInfo structure used by RFC 8017
405 * §9.2 steps 3–6. If \p md_alg is a valid hash
406 * algorithm then \p hash is the digest itself, and this
407 * function calculates the DigestInfo encoding internally.
408 * \param hash Hash of the message to sign
409 * \param hash_len Hash length
410 * \param sig Signature to verify
411 * \param sig_len Signature length
412 *
413 * \return 0 on success (signature is valid),
414 * #MBEDTLS_ERR_PK_SIG_LEN_MISMATCH if there is a valid
415 * signature in sig but its length is less than \p siglen,
416 * or a specific error code.
417 *
418 * \note For RSA keys, the default padding type is PKCS#1 v1.5.
419 * Use \c mbedtls_pk_verify_ext( MBEDTLS_PK_RSASSA_PSS, ... )
420 * to verify RSASSA_PSS signatures.
421 */
422 int mbedtls_pk_verify( mbedtls_pk_context *ctx, mbedtls_md_type_t md_alg,
423 const unsigned char *hash, size_t hash_len,
424 const unsigned char *sig, size_t sig_len );
425
426 /**
427 * \brief Restartable version of \c mbedtls_pk_verify()
428 *
429 * \note Performs the same job as \c mbedtls_pk_verify(), but can
430 * return early and restart according to the limit set with
431 * \c mbedtls_ecp_set_max_ops() to reduce blocking for ECC
432 * operations. For RSA, same as \c mbedtls_pk_verify().
433 *
434 * \param ctx The PK context to use. It must have been set up.
435 * \param md_alg Hash algorithm used (see notes)
436 * \param hash Hash of the message to sign
437 * \param hash_len Hash length or 0 (see notes)
438 * \param sig Signature to verify
439 * \param sig_len Signature length
440 * \param rs_ctx Restart context (NULL to disable restart)
441 *
442 * \return See \c mbedtls_pk_verify(), or
443 * \return #MBEDTLS_ERR_ECP_IN_PROGRESS if maximum number of
444 * operations was reached: see \c mbedtls_ecp_set_max_ops().
445 */
446 int mbedtls_pk_verify_restartable( mbedtls_pk_context *ctx,
447 mbedtls_md_type_t md_alg,
448 const unsigned char *hash, size_t hash_len,
449 const unsigned char *sig, size_t sig_len,
450 mbedtls_pk_restart_ctx *rs_ctx );
451
452 /**
453 * \brief Verify signature, with options.
454 * (Includes verification of the padding depending on type.)
455 *
456 * \param type Signature type (inc. possible padding type) to verify
457 * \param options Pointer to type-specific options, or NULL
458 * \param ctx The PK context to use. It must have been set up.
459 * \param md_alg Hash algorithm used (see notes)
460 * \param hash Hash of the message to sign
461 * \param hash_len Hash length or 0 (see notes)
462 * \param sig Signature to verify
463 * \param sig_len Signature length
464 *
465 * \return 0 on success (signature is valid),
466 * #MBEDTLS_ERR_PK_TYPE_MISMATCH if the PK context can't be
467 * used for this type of signatures,
468 * #MBEDTLS_ERR_PK_SIG_LEN_MISMATCH if there is a valid
469 * signature in sig but its length is less than \p siglen,
470 * or a specific error code.
471 *
472 * \note If hash_len is 0, then the length associated with md_alg
473 * is used instead, or an error returned if it is invalid.
474 *
475 * \note md_alg may be MBEDTLS_MD_NONE, only if hash_len != 0
476 *
477 * \note If type is MBEDTLS_PK_RSASSA_PSS, then options must point
478 * to a mbedtls_pk_rsassa_pss_options structure,
479 * otherwise it must be NULL.
480 */
481 int mbedtls_pk_verify_ext( mbedtls_pk_type_t type, const void *options,
482 mbedtls_pk_context *ctx, mbedtls_md_type_t md_alg,
483 const unsigned char *hash, size_t hash_len,
484 const unsigned char *sig, size_t sig_len );
485
486 /**
487 * \brief Make signature, including padding if relevant.
488 *
489 * \param ctx The PK context to use. It must have been set up
490 * with a private key.
491 * \param md_alg Hash algorithm used (see notes)
492 * \param hash Hash of the message to sign
493 * \param hash_len Hash length
494 * \param sig Place to write the signature.
495 * It must have enough room for the signature.
496 * #MBEDTLS_PK_SIGNATURE_MAX_SIZE is always enough.
497 * You may use a smaller buffer if it is large enough
498 * given the key type.
499 * \param sig_size The size of the \p sig buffer in bytes.
500 * \param sig_len On successful return,
501 * the number of bytes written to \p sig.
502 * \param f_rng RNG function, must not be \c NULL.
503 * \param p_rng RNG parameter
504 *
505 * \return 0 on success, or a specific error code.
506 *
507 * \note For RSA keys, the default padding type is PKCS#1 v1.5.
508 * There is no interface in the PK module to make RSASSA-PSS
509 * signatures yet.
510 *
511 * \note For RSA, md_alg may be MBEDTLS_MD_NONE if hash_len != 0.
512 * For ECDSA, md_alg may never be MBEDTLS_MD_NONE.
513 */
514 int mbedtls_pk_sign( mbedtls_pk_context *ctx, mbedtls_md_type_t md_alg,
515 const unsigned char *hash, size_t hash_len,
516 unsigned char *sig, size_t sig_size, size_t *sig_len,
517 int (*f_rng)(void *, unsigned char *, size_t), void *p_rng );
518
519 /**
520 * \brief Restartable version of \c mbedtls_pk_sign()
521 *
522 * \note Performs the same job as \c mbedtls_pk_sign(), but can
523 * return early and restart according to the limit set with
524 * \c mbedtls_ecp_set_max_ops() to reduce blocking for ECC
525 * operations. For RSA, same as \c mbedtls_pk_sign().
526 *
527 * \param ctx The PK context to use. It must have been set up
528 * with a private key.
529 * \param md_alg Hash algorithm used (see notes for mbedtls_pk_sign())
530 * \param hash Hash of the message to sign
531 * \param hash_len Hash length
532 * \param sig Place to write the signature.
533 * It must have enough room for the signature.
534 * #MBEDTLS_PK_SIGNATURE_MAX_SIZE is always enough.
535 * You may use a smaller buffer if it is large enough
536 * given the key type.
537 * \param sig_size The size of the \p sig buffer in bytes.
538 * \param sig_len On successful return,
539 * the number of bytes written to \p sig.
540 * \param f_rng RNG function, must not be \c NULL.
541 * \param p_rng RNG parameter
542 * \param rs_ctx Restart context (NULL to disable restart)
543 *
544 * \return See \c mbedtls_pk_sign().
545 * \return #MBEDTLS_ERR_ECP_IN_PROGRESS if maximum number of
546 * operations was reached: see \c mbedtls_ecp_set_max_ops().
547 */
548 int mbedtls_pk_sign_restartable( mbedtls_pk_context *ctx,
549 mbedtls_md_type_t md_alg,
550 const unsigned char *hash, size_t hash_len,
551 unsigned char *sig, size_t sig_size, size_t *sig_len,
552 int (*f_rng)(void *, unsigned char *, size_t), void *p_rng,
553 mbedtls_pk_restart_ctx *rs_ctx );
554
555 /**
556 * \brief Decrypt message (including padding if relevant).
557 *
558 * \param ctx The PK context to use. It must have been set up
559 * with a private key.
560 * \param input Input to decrypt
561 * \param ilen Input size
562 * \param output Decrypted output
563 * \param olen Decrypted message length
564 * \param osize Size of the output buffer
565 * \param f_rng RNG function, must not be \c NULL.
566 * \param p_rng RNG parameter
567 *
568 * \note For RSA keys, the default padding type is PKCS#1 v1.5.
569 *
570 * \return 0 on success, or a specific error code.
571 */
572 int mbedtls_pk_decrypt( mbedtls_pk_context *ctx,
573 const unsigned char *input, size_t ilen,
574 unsigned char *output, size_t *olen, size_t osize,
575 int (*f_rng)(void *, unsigned char *, size_t), void *p_rng );
576
577 /**
578 * \brief Encrypt message (including padding if relevant).
579 *
580 * \param ctx The PK context to use. It must have been set up.
581 * \param input Message to encrypt
582 * \param ilen Message size
583 * \param output Encrypted output
584 * \param olen Encrypted output length
585 * \param osize Size of the output buffer
586 * \param f_rng RNG function, must not be \c NULL.
587 * \param p_rng RNG parameter
588 *
589 * \note \p f_rng is used for padding generation.
590 *
591 * \note For RSA keys, the default padding type is PKCS#1 v1.5.
592 *
593 * \return 0 on success, or a specific error code.
594 */
595 int mbedtls_pk_encrypt( mbedtls_pk_context *ctx,
596 const unsigned char *input, size_t ilen,
597 unsigned char *output, size_t *olen, size_t osize,
598 int (*f_rng)(void *, unsigned char *, size_t), void *p_rng );
599
600 /**
601 * \brief Check if a public-private pair of keys matches.
602 *
603 * \param pub Context holding a public key.
604 * \param prv Context holding a private (and public) key.
605 * \param f_rng RNG function, must not be \c NULL.
606 * \param p_rng RNG parameter
607 *
608 * \return \c 0 on success (keys were checked and match each other).
609 * \return #MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE if the keys could not
610 * be checked - in that case they may or may not match.
611 * \return #MBEDTLS_ERR_PK_BAD_INPUT_DATA if a context is invalid.
612 * \return Another non-zero value if the keys do not match.
613 */
614 int mbedtls_pk_check_pair( const mbedtls_pk_context *pub,
615 const mbedtls_pk_context *prv,
616 int (*f_rng)(void *, unsigned char *, size_t),
617 void *p_rng );
618
619 /**
620 * \brief Export debug information
621 *
622 * \param ctx The PK context to use. It must have been initialized.
623 * \param items Place to write debug items
624 *
625 * \return 0 on success or MBEDTLS_ERR_PK_BAD_INPUT_DATA
626 */
627 int mbedtls_pk_debug( const mbedtls_pk_context *ctx, mbedtls_pk_debug_item *items );
628
629 /**
630 * \brief Access the type name
631 *
632 * \param ctx The PK context to use. It must have been initialized.
633 *
634 * \return Type name on success, or "invalid PK"
635 */
636 const char * mbedtls_pk_get_name( const mbedtls_pk_context *ctx );
637
638 /**
639 * \brief Get the key type
640 *
641 * \param ctx The PK context to use. It must have been initialized.
642 *
643 * \return Type on success.
644 * \return #MBEDTLS_PK_NONE for a context that has not been set up.
645 */
646 mbedtls_pk_type_t mbedtls_pk_get_type( const mbedtls_pk_context *ctx );
647
648 #if defined(MBEDTLS_PK_PARSE_C)
649 /** \ingroup pk_module */
650 /**
651 * \brief Parse a private key in PEM or DER format
652 *
653 * \param ctx The PK context to fill. It must have been initialized
654 * but not set up.
655 * \param key Input buffer to parse.
656 * The buffer must contain the input exactly, with no
657 * extra trailing material. For PEM, the buffer must
658 * contain a null-terminated string.
659 * \param keylen Size of \b key in bytes.
660 * For PEM data, this includes the terminating null byte,
661 * so \p keylen must be equal to `strlen(key) + 1`.
662 * \param pwd Optional password for decryption.
663 * Pass \c NULL if expecting a non-encrypted key.
664 * Pass a string of \p pwdlen bytes if expecting an encrypted
665 * key; a non-encrypted key will also be accepted.
666 * The empty password is not supported.
667 * \param pwdlen Size of the password in bytes.
668 * Ignored if \p pwd is \c NULL.
669 * \param f_rng RNG function, must not be \c NULL. Used for blinding.
670 * \param p_rng RNG parameter
671 *
672 * \note On entry, ctx must be empty, either freshly initialised
673 * with mbedtls_pk_init() or reset with mbedtls_pk_free(). If you need a
674 * specific key type, check the result with mbedtls_pk_can_do().
675 *
676 * \note The key is also checked for correctness.
677 *
678 * \return 0 if successful, or a specific PK or PEM error code
679 */
680 int mbedtls_pk_parse_key( mbedtls_pk_context *ctx,
681 const unsigned char *key, size_t keylen,
682 const unsigned char *pwd, size_t pwdlen,
683 int (*f_rng)(void *, unsigned char *, size_t), void *p_rng );
684
685 /** \ingroup pk_module */
686 /**
687 * \brief Parse a public key in PEM or DER format
688 *
689 * \param ctx The PK context to fill. It must have been initialized
690 * but not set up.
691 * \param key Input buffer to parse.
692 * The buffer must contain the input exactly, with no
693 * extra trailing material. For PEM, the buffer must
694 * contain a null-terminated string.
695 * \param keylen Size of \b key in bytes.
696 * For PEM data, this includes the terminating null byte,
697 * so \p keylen must be equal to `strlen(key) + 1`.
698 *
699 * \note On entry, ctx must be empty, either freshly initialised
700 * with mbedtls_pk_init() or reset with mbedtls_pk_free(). If you need a
701 * specific key type, check the result with mbedtls_pk_can_do().
702 *
703 * \note The key is also checked for correctness.
704 *
705 * \return 0 if successful, or a specific PK or PEM error code
706 */
707 int mbedtls_pk_parse_public_key( mbedtls_pk_context *ctx,
708 const unsigned char *key, size_t keylen );
709
710 #if defined(MBEDTLS_FS_IO)
711 /** \ingroup pk_module */
712 /**
713 * \brief Load and parse a private key
714 *
715 * \param ctx The PK context to fill. It must have been initialized
716 * but not set up.
717 * \param path filename to read the private key from
718 * \param password Optional password to decrypt the file.
719 * Pass \c NULL if expecting a non-encrypted key.
720 * Pass a null-terminated string if expecting an encrypted
721 * key; a non-encrypted key will also be accepted.
722 * The empty password is not supported.
723 * \param f_rng RNG function, must not be \c NULL. Used for blinding.
724 * \param p_rng RNG parameter
725 *
726 * \note On entry, ctx must be empty, either freshly initialised
727 * with mbedtls_pk_init() or reset with mbedtls_pk_free(). If you need a
728 * specific key type, check the result with mbedtls_pk_can_do().
729 *
730 * \note The key is also checked for correctness.
731 *
732 * \return 0 if successful, or a specific PK or PEM error code
733 */
734 int mbedtls_pk_parse_keyfile( mbedtls_pk_context *ctx,
735 const char *path, const char *password,
736 int (*f_rng)(void *, unsigned char *, size_t), void *p_rng );
737
738 /** \ingroup pk_module */
739 /**
740 * \brief Load and parse a public key
741 *
742 * \param ctx The PK context to fill. It must have been initialized
743 * but not set up.
744 * \param path filename to read the public key from
745 *
746 * \note On entry, ctx must be empty, either freshly initialised
747 * with mbedtls_pk_init() or reset with mbedtls_pk_free(). If
748 * you need a specific key type, check the result with
749 * mbedtls_pk_can_do().
750 *
751 * \note The key is also checked for correctness.
752 *
753 * \return 0 if successful, or a specific PK or PEM error code
754 */
755 int mbedtls_pk_parse_public_keyfile( mbedtls_pk_context *ctx, const char *path );
756 #endif /* MBEDTLS_FS_IO */
757 #endif /* MBEDTLS_PK_PARSE_C */
758
759 #if defined(MBEDTLS_PK_WRITE_C)
760 /**
761 * \brief Write a private key to a PKCS#1 or SEC1 DER structure
762 * Note: data is written at the end of the buffer! Use the
763 * return value to determine where you should start
764 * using the buffer
765 *
766 * \param ctx PK context which must contain a valid private key.
767 * \param buf buffer to write to
768 * \param size size of the buffer
769 *
770 * \return length of data written if successful, or a specific
771 * error code
772 */
773 int mbedtls_pk_write_key_der( const mbedtls_pk_context *ctx, unsigned char *buf, size_t size );
774
775 /**
776 * \brief Write a public key to a SubjectPublicKeyInfo DER structure
777 * Note: data is written at the end of the buffer! Use the
778 * return value to determine where you should start
779 * using the buffer
780 *
781 * \param ctx PK context which must contain a valid public or private key.
782 * \param buf buffer to write to
783 * \param size size of the buffer
784 *
785 * \return length of data written if successful, or a specific
786 * error code
787 */
788 int mbedtls_pk_write_pubkey_der( const mbedtls_pk_context *ctx, unsigned char *buf, size_t size );
789
790 #if defined(MBEDTLS_PEM_WRITE_C)
791 /**
792 * \brief Write a public key to a PEM string
793 *
794 * \param ctx PK context which must contain a valid public or private key.
795 * \param buf Buffer to write to. The output includes a
796 * terminating null byte.
797 * \param size Size of the buffer in bytes.
798 *
799 * \return 0 if successful, or a specific error code
800 */
801 int mbedtls_pk_write_pubkey_pem( const mbedtls_pk_context *ctx, unsigned char *buf, size_t size );
802
803 /**
804 * \brief Write a private key to a PKCS#1 or SEC1 PEM string
805 *
806 * \param ctx PK context which must contain a valid private key.
807 * \param buf Buffer to write to. The output includes a
808 * terminating null byte.
809 * \param size Size of the buffer in bytes.
810 *
811 * \return 0 if successful, or a specific error code
812 */
813 int mbedtls_pk_write_key_pem( const mbedtls_pk_context *ctx, unsigned char *buf, size_t size );
814 #endif /* MBEDTLS_PEM_WRITE_C */
815 #endif /* MBEDTLS_PK_WRITE_C */
816
817 /*
818 * WARNING: Low-level functions. You probably do not want to use these unless
819 * you are certain you do ;)
820 */
821
822 #if defined(MBEDTLS_PK_PARSE_C)
823 /**
824 * \brief Parse a SubjectPublicKeyInfo DER structure
825 *
826 * \param p the position in the ASN.1 data
827 * \param end end of the buffer
828 * \param pk The PK context to fill. It must have been initialized
829 * but not set up.
830 *
831 * \return 0 if successful, or a specific PK error code
832 */
833 int mbedtls_pk_parse_subpubkey( unsigned char **p, const unsigned char *end,
834 mbedtls_pk_context *pk );
835 #endif /* MBEDTLS_PK_PARSE_C */
836
837 #if defined(MBEDTLS_PK_WRITE_C)
838 /**
839 * \brief Write a subjectPublicKey to ASN.1 data
840 * Note: function works backwards in data buffer
841 *
842 * \param p reference to current position pointer
843 * \param start start of the buffer (for bounds-checking)
844 * \param key PK context which must contain a valid public or private key.
845 *
846 * \return the length written or a negative error code
847 */
848 int mbedtls_pk_write_pubkey( unsigned char **p, unsigned char *start,
849 const mbedtls_pk_context *key );
850 #endif /* MBEDTLS_PK_WRITE_C */
851
852 /*
853 * Internal module functions. You probably do not want to use these unless you
854 * know you do.
855 */
856 #if defined(MBEDTLS_FS_IO)
857 int mbedtls_pk_load_file( const char *path, unsigned char **buf, size_t *n );
858 #endif
859
860 #if defined(MBEDTLS_USE_PSA_CRYPTO)
861 /**
862 * \brief Turn an EC key into an opaque one.
863 *
864 * \warning This is a temporary utility function for tests. It might
865 * change or be removed at any time without notice.
866 *
867 * \note Only ECDSA keys are supported so far. Signing with the
868 * specified hash is the only allowed use of that key.
869 *
870 * \param pk Input: the EC key to import to a PSA key.
871 * Output: a PK context wrapping that PSA key.
872 * \param key Output: a PSA key identifier.
873 * It's the caller's responsibility to call
874 * psa_destroy_key() on that key identifier after calling
875 * mbedtls_pk_free() on the PK context.
876 * \param hash_alg The hash algorithm to allow for use with that key.
877 *
878 * \return \c 0 if successful.
879 * \return An Mbed TLS error code otherwise.
880 */
881 int mbedtls_pk_wrap_as_opaque( mbedtls_pk_context *pk,
882 psa_key_id_t *key,
883 psa_algorithm_t hash_alg );
884 #endif /* MBEDTLS_USE_PSA_CRYPTO */
885
886 #ifdef __cplusplus
887 }
888 #endif
889
890 #endif /* MBEDTLS_PK_H */
891
