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