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 #include "mbedtls/private_access.h"
14
15 #include "mbedtls/build_info.h"
16
17 #include "mbedtls/md.h"
18
19 #if defined(MBEDTLS_RSA_C)
20 #include "mbedtls/rsa.h"
21 #endif
22
23 #if defined(MBEDTLS_ECP_C)
24 #include "mbedtls/ecp.h"
25 #endif
26
27 #if defined(MBEDTLS_ECDSA_C)
28 #include "mbedtls/ecdsa.h"
29 #endif
30
31 #if defined(MBEDTLS_PSA_CRYPTO_CLIENT)
32 #include "psa/crypto.h"
33 #endif
34
35 /** Memory allocation failed. */
36 #define MBEDTLS_ERR_PK_ALLOC_FAILED -0x3F80
37 /** Type mismatch, eg attempt to encrypt with an ECDSA key */
38 #define MBEDTLS_ERR_PK_TYPE_MISMATCH -0x3F00
39 /** Bad input parameters to function. */
40 #define MBEDTLS_ERR_PK_BAD_INPUT_DATA -0x3E80
41 /** Read/write of file failed. */
42 #define MBEDTLS_ERR_PK_FILE_IO_ERROR -0x3E00
43 /** Unsupported key version */
44 #define MBEDTLS_ERR_PK_KEY_INVALID_VERSION -0x3D80
45 /** Invalid key tag or value. */
46 #define MBEDTLS_ERR_PK_KEY_INVALID_FORMAT -0x3D00
47 /** Key algorithm is unsupported (only RSA and EC are supported). */
48 #define MBEDTLS_ERR_PK_UNKNOWN_PK_ALG -0x3C80
49 /** Private key password can't be empty. */
50 #define MBEDTLS_ERR_PK_PASSWORD_REQUIRED -0x3C00
51 /** Given private key password does not allow for correct decryption. */
52 #define MBEDTLS_ERR_PK_PASSWORD_MISMATCH -0x3B80
53 /** The pubkey tag or value is invalid (only RSA and EC are supported). */
54 #define MBEDTLS_ERR_PK_INVALID_PUBKEY -0x3B00
55 /** The algorithm tag or value is invalid. */
56 #define MBEDTLS_ERR_PK_INVALID_ALG -0x3A80
57 /** Elliptic curve is unsupported (only NIST curves are supported). */
58 #define MBEDTLS_ERR_PK_UNKNOWN_NAMED_CURVE -0x3A00
59 /** Unavailable feature, e.g. RSA disabled for RSA key. */
60 #define MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE -0x3980
61 /** The buffer contains a valid signature followed by more data. */
62 #define MBEDTLS_ERR_PK_SIG_LEN_MISMATCH -0x3900
63 /** The output buffer is too small. */
64 #define MBEDTLS_ERR_PK_BUFFER_TOO_SMALL -0x3880
65
66 #ifdef __cplusplus
67 extern "C" {
68 #endif
69
70 /**
71 * \brief Public key types
72 */
73 typedef enum {
74 MBEDTLS_PK_NONE=0,
75 MBEDTLS_PK_RSA,
76 MBEDTLS_PK_ECKEY,
77 MBEDTLS_PK_ECKEY_DH,
78 MBEDTLS_PK_ECDSA,
79 MBEDTLS_PK_RSA_ALT,
80 MBEDTLS_PK_RSASSA_PSS,
81 MBEDTLS_PK_OPAQUE,
82 } mbedtls_pk_type_t;
83
84 /**
85 * \brief Options for RSASSA-PSS signature verification.
86 * See \c mbedtls_rsa_rsassa_pss_verify_ext()
87 */
88 typedef struct mbedtls_pk_rsassa_pss_options {
89 /** The digest to use for MGF1 in PSS.
90 *
91 * \note When #MBEDTLS_USE_PSA_CRYPTO is enabled and #MBEDTLS_RSA_C is
92 * disabled, this must be equal to the \c md_alg argument passed
93 * to mbedtls_pk_verify_ext(). In a future version of the library,
94 * this constraint may apply whenever #MBEDTLS_USE_PSA_CRYPTO is
95 * enabled regardless of the status of #MBEDTLS_RSA_C.
96 */
97 mbedtls_md_type_t mgf1_hash_id;
98
99 /** The expected length of the salt, in bytes. This may be
100 * #MBEDTLS_RSA_SALT_LEN_ANY to accept any salt length.
101 *
102 * \note When #MBEDTLS_USE_PSA_CRYPTO is enabled, only
103 * #MBEDTLS_RSA_SALT_LEN_ANY is valid. Any other value may be
104 * ignored (allowing any salt length).
105 */
106 int expected_salt_len;
107
108 } mbedtls_pk_rsassa_pss_options;
109
110 /**
111 * \brief Maximum size of a signature made by mbedtls_pk_sign().
112 */
113 /* We need to set MBEDTLS_PK_SIGNATURE_MAX_SIZE to the maximum signature
114 * size among the supported signature types. Do it by starting at 0,
115 * then incrementally increasing to be large enough for each supported
116 * signature mechanism.
117 *
118 * The resulting value can be 0, for example if MBEDTLS_ECDH_C is enabled
119 * (which allows the pk module to be included) but neither MBEDTLS_ECDSA_C
120 * nor MBEDTLS_RSA_C nor any opaque signature mechanism (PSA or RSA_ALT).
121 */
122 #define MBEDTLS_PK_SIGNATURE_MAX_SIZE 0
123
124 #if (defined(MBEDTLS_RSA_C) || defined(MBEDTLS_PK_RSA_ALT_SUPPORT)) && \
125 MBEDTLS_MPI_MAX_SIZE > MBEDTLS_PK_SIGNATURE_MAX_SIZE
126 /* For RSA, the signature can be as large as the bignum module allows.
127 * For RSA_ALT, the signature size is not necessarily tied to what the
128 * bignum module can do, but in the absence of any specific setting,
129 * we use that (rsa_alt_sign_wrap in library/pk_wrap.h will check). */
130 #undef MBEDTLS_PK_SIGNATURE_MAX_SIZE
131 #define MBEDTLS_PK_SIGNATURE_MAX_SIZE MBEDTLS_MPI_MAX_SIZE
132 #endif
133
134 #if defined(MBEDTLS_ECDSA_C) && \
135 MBEDTLS_ECDSA_MAX_LEN > MBEDTLS_PK_SIGNATURE_MAX_SIZE
136 /* For ECDSA, the ecdsa module exports a constant for the maximum
137 * signature size. */
138 #undef MBEDTLS_PK_SIGNATURE_MAX_SIZE
139 #define MBEDTLS_PK_SIGNATURE_MAX_SIZE MBEDTLS_ECDSA_MAX_LEN
140 #endif
141
142 #if defined(MBEDTLS_USE_PSA_CRYPTO)
143 #if PSA_SIGNATURE_MAX_SIZE > MBEDTLS_PK_SIGNATURE_MAX_SIZE
144 /* PSA_SIGNATURE_MAX_SIZE is the maximum size of a signature made
145 * through the PSA API in the PSA representation. */
146 #undef MBEDTLS_PK_SIGNATURE_MAX_SIZE
147 #define MBEDTLS_PK_SIGNATURE_MAX_SIZE PSA_SIGNATURE_MAX_SIZE
148 #endif
149
150 #if PSA_VENDOR_ECDSA_SIGNATURE_MAX_SIZE + 11 > MBEDTLS_PK_SIGNATURE_MAX_SIZE
151 /* The Mbed TLS representation is different for ECDSA signatures:
152 * PSA uses the raw concatenation of r and s,
153 * whereas Mbed TLS uses the ASN.1 representation (SEQUENCE of two INTEGERs).
154 * Add the overhead of ASN.1: up to (1+2) + 2 * (1+2+1) for the
155 * types, lengths (represented by up to 2 bytes), and potential leading
156 * zeros of the INTEGERs and the SEQUENCE. */
157 #undef MBEDTLS_PK_SIGNATURE_MAX_SIZE
158 #define MBEDTLS_PK_SIGNATURE_MAX_SIZE (PSA_VENDOR_ECDSA_SIGNATURE_MAX_SIZE + 11)
159 #endif
160 #endif /* defined(MBEDTLS_USE_PSA_CRYPTO) */
161
162 /* Internal helper to define which fields in the pk_context structure below
163 * should be used for EC keys: legacy ecp_keypair or the raw (PSA friendly)
164 * format. It should be noted that this only affects how data is stored, not
165 * which functions are used for various operations. The overall picture looks
166 * like this:
167 * - if USE_PSA is not defined and ECP_C is defined then use ecp_keypair data
168 * structure and legacy functions
169 * - if USE_PSA is defined and
170 * - if ECP_C then use ecp_keypair structure, convert data to a PSA friendly
171 * format and use PSA functions
172 * - if !ECP_C then use new raw data and PSA functions directly.
173 *
174 * The main reason for the "intermediate" (USE_PSA + ECP_C) above is that as long
175 * as ECP_C is defined mbedtls_pk_ec() gives the user a read/write access to the
176 * ecp_keypair structure inside the pk_context so they can modify it using
177 * ECP functions which are not under PK module's control.
178 */
179 #if defined(MBEDTLS_USE_PSA_CRYPTO) && defined(PSA_WANT_KEY_TYPE_ECC_PUBLIC_KEY) && \
180 !defined(MBEDTLS_ECP_C)
181 #define MBEDTLS_PK_USE_PSA_EC_DATA
182 #endif
183
184 /**
185 * \brief Types for interfacing with the debug module
186 */
187 typedef enum {
188 MBEDTLS_PK_DEBUG_NONE = 0,
189 MBEDTLS_PK_DEBUG_MPI,
190 MBEDTLS_PK_DEBUG_ECP,
191 MBEDTLS_PK_DEBUG_PSA_EC,
192 } mbedtls_pk_debug_type;
193
194 /**
195 * \brief Item to send to the debug module
196 */
197 typedef struct mbedtls_pk_debug_item {
198 mbedtls_pk_debug_type MBEDTLS_PRIVATE(type);
199 const char *MBEDTLS_PRIVATE(name);
200 void *MBEDTLS_PRIVATE(value);
201 } mbedtls_pk_debug_item;
202
203 /** Maximum number of item send for debugging, plus 1 */
204 #define MBEDTLS_PK_DEBUG_MAX_ITEMS 3
205
206 /**
207 * \brief Public key information and operations
208 *
209 * \note The library does not support custom pk info structures,
210 * only built-in structures returned by
211 * mbedtls_cipher_info_from_type().
212 */
213 typedef struct mbedtls_pk_info_t mbedtls_pk_info_t;
214
215 #define MBEDTLS_PK_MAX_EC_PUBKEY_RAW_LEN \
216 PSA_KEY_EXPORT_ECC_PUBLIC_KEY_MAX_SIZE(PSA_VENDOR_ECC_MAX_CURVE_BITS)
217 /**
218 * \brief Public key container
219 */
220 typedef struct mbedtls_pk_context {
221 const mbedtls_pk_info_t *MBEDTLS_PRIVATE(pk_info); /**< Public key information */
222 void *MBEDTLS_PRIVATE(pk_ctx); /**< Underlying public key context */
223 /* The following field is used to store the ID of a private key in the
224 * following cases:
225 * - opaque key when MBEDTLS_USE_PSA_CRYPTO is defined
226 * - normal key when MBEDTLS_PK_USE_PSA_EC_DATA is defined. In this case:
227 * - the pk_ctx above is not not used to store the private key anymore.
228 * Actually that field not populated at all in this case because also
229 * the public key will be stored in raw format as explained below
230 * - this ID is used for all private key operations (ex: sign, check
231 * key pair, key write, etc) using PSA functions
232 *
233 * Note: this private key storing solution only affects EC keys, not the
234 * other ones. The latters still use the pk_ctx to store their own
235 * context. */
236 #if defined(MBEDTLS_USE_PSA_CRYPTO)
237 mbedtls_svc_key_id_t MBEDTLS_PRIVATE(priv_id); /**< Key ID for opaque keys */
238 #endif /* MBEDTLS_USE_PSA_CRYPTO */
239 /* The following fields are meant for storing the public key in raw format
240 * which is handy for:
241 * - easily importing it into the PSA context
242 * - reducing the ECP module dependencies in the PK one.
243 *
244 * When MBEDTLS_PK_USE_PSA_EC_DATA is enabled:
245 * - the pk_ctx above is not used anymore for storing the public key
246 * inside the ecp_keypair structure
247 * - the following fields are used for all public key operations: signature
248 * verify, key pair check and key write.
249 * - For a key pair, priv_id contains the private key. For a public key,
250 * priv_id is null.
251 * Of course, when MBEDTLS_PK_USE_PSA_EC_DATA is not enabled, the legacy
252 * ecp_keypair structure is used for storing the public key and performing
253 * all the operations.
254 *
255 * Note: This new public key storing solution only works for EC keys, not
256 * other ones. The latters still use pk_ctx to store their own
257 * context.
258 */
259 #if defined(MBEDTLS_PK_USE_PSA_EC_DATA)
260 uint8_t MBEDTLS_PRIVATE(pub_raw)[MBEDTLS_PK_MAX_EC_PUBKEY_RAW_LEN]; /**< Raw public key */
261 size_t MBEDTLS_PRIVATE(pub_raw_len); /**< Valid bytes in "pub_raw" */
262 psa_ecc_family_t MBEDTLS_PRIVATE(ec_family); /**< EC family of pk */
263 size_t MBEDTLS_PRIVATE(ec_bits); /**< Curve's bits of pk */
264 #endif /* MBEDTLS_PK_USE_PSA_EC_DATA */
265 } mbedtls_pk_context;
266
267 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
268 /**
269 * \brief Context for resuming operations
270 */
271 typedef struct {
272 const mbedtls_pk_info_t *MBEDTLS_PRIVATE(pk_info); /**< Public key information */
273 void *MBEDTLS_PRIVATE(rs_ctx); /**< Underlying restart context */
274 } mbedtls_pk_restart_ctx;
275 #else /* MBEDTLS_ECDSA_C && MBEDTLS_ECP_RESTARTABLE */
276 /* Now we can declare functions that take a pointer to that */
277 typedef void mbedtls_pk_restart_ctx;
278 #endif /* MBEDTLS_ECDSA_C && MBEDTLS_ECP_RESTARTABLE */
279
280 #if defined(MBEDTLS_PK_RSA_ALT_SUPPORT)
281 /**
282 * \brief Types for RSA-alt abstraction
283 */
284 typedef int (*mbedtls_pk_rsa_alt_decrypt_func)(void *ctx, size_t *olen,
285 const unsigned char *input, unsigned char *output,
286 size_t output_max_len);
287 typedef int (*mbedtls_pk_rsa_alt_sign_func)(void *ctx,
288 int (*f_rng)(void *, unsigned char *, size_t),
289 void *p_rng,
290 mbedtls_md_type_t md_alg, unsigned int hashlen,
291 const unsigned char *hash, unsigned char *sig);
292 typedef size_t (*mbedtls_pk_rsa_alt_key_len_func)(void *ctx);
293 #endif /* MBEDTLS_PK_RSA_ALT_SUPPORT */
294
295 /**
296 * \brief Return information associated with the given PK type
297 *
298 * \param pk_type PK type to search for.
299 *
300 * \return The PK info associated with the type or NULL if not found.
301 */
302 const mbedtls_pk_info_t *mbedtls_pk_info_from_type(mbedtls_pk_type_t pk_type);
303
304 /**
305 * \brief Initialize a #mbedtls_pk_context (as NONE).
306 *
307 * \param ctx The context to initialize.
308 * This must not be \c NULL.
309 */
310 void mbedtls_pk_init(mbedtls_pk_context *ctx);
311
312 /**
313 * \brief Free the components of a #mbedtls_pk_context.
314 *
315 * \param ctx The context to clear. It must have been initialized.
316 * If this is \c NULL, this function does nothing.
317 *
318 * \note For contexts that have been set up with
319 * mbedtls_pk_setup_opaque(), this does not free the underlying
320 * PSA key and you still need to call psa_destroy_key()
321 * independently if you want to destroy that key.
322 */
323 void mbedtls_pk_free(mbedtls_pk_context *ctx);
324
325 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
326 /**
327 * \brief Initialize a restart context
328 *
329 * \param ctx The context to initialize.
330 * This must not be \c NULL.
331 */
332 void mbedtls_pk_restart_init(mbedtls_pk_restart_ctx *ctx);
333
334 /**
335 * \brief Free the components of a restart context
336 *
337 * \param ctx The context to clear. It must have been initialized.
338 * If this is \c NULL, this function does nothing.
339 */
340 void mbedtls_pk_restart_free(mbedtls_pk_restart_ctx *ctx);
341 #endif /* MBEDTLS_ECDSA_C && MBEDTLS_ECP_RESTARTABLE */
342
343 /**
344 * \brief Initialize a PK context with the information given
345 * and allocates the type-specific PK subcontext.
346 *
347 * \param ctx Context to initialize. It must not have been set
348 * up yet (type #MBEDTLS_PK_NONE).
349 * \param info Information to use
350 *
351 * \return 0 on success,
352 * MBEDTLS_ERR_PK_BAD_INPUT_DATA on invalid input,
353 * MBEDTLS_ERR_PK_ALLOC_FAILED on allocation failure.
354 *
355 * \note For contexts holding an RSA-alt key, use
356 * \c mbedtls_pk_setup_rsa_alt() instead.
357 */
358 int mbedtls_pk_setup(mbedtls_pk_context *ctx, const mbedtls_pk_info_t *info);
359
360 #if defined(MBEDTLS_USE_PSA_CRYPTO)
361 /**
362 * \brief Initialize a PK context to wrap a PSA key.
363 *
364 * This function creates a PK context which wraps a PSA key. The PSA wrapped
365 * key must be an EC or RSA key pair (DH is not suported in the PK module).
366 *
367 * Under the hood PSA functions will be used to perform the required
368 * operations and, based on the key type, used algorithms will be:
369 * * EC:
370 * * verify, verify_ext, sign, sign_ext: ECDSA.
371 * * RSA:
372 * * sign, decrypt: use the primary algorithm in the wrapped PSA key;
373 * * sign_ext: RSA PSS if the pk_type is #MBEDTLS_PK_RSASSA_PSS, otherwise
374 * it falls back to the sign() case;
375 * * verify, verify_ext, encrypt: not supported.
376 *
377 * In order for the above operations to succeed, the policy of the wrapped PSA
378 * key must allow the specified algorithm.
379 *
380 * Opaque PK contexts wrapping an EC keys also support \c mbedtls_pk_check_pair(),
381 * whereas RSA ones do not.
382 *
383 * \warning The PSA wrapped key must remain valid as long as the wrapping PK
384 * context is in use, that is at least between the point this function
385 * is called and the point mbedtls_pk_free() is called on this context.
386 *
387 * \param ctx The context to initialize. It must be empty (type NONE).
388 * \param key The PSA key to wrap, which must hold an ECC or RSA key pair.
389 *
390 * \return \c 0 on success.
391 * \return #MBEDTLS_ERR_PK_BAD_INPUT_DATA on invalid input (context already
392 * used, invalid key identifier).
393 * \return #MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE if the key is not an ECC or
394 * RSA key pair.
395 * \return #MBEDTLS_ERR_PK_ALLOC_FAILED on allocation failure.
396 */
397 int mbedtls_pk_setup_opaque(mbedtls_pk_context *ctx,
398 const mbedtls_svc_key_id_t key);
399 #endif /* MBEDTLS_USE_PSA_CRYPTO */
400
401 #if defined(MBEDTLS_PK_RSA_ALT_SUPPORT)
402 /**
403 * \brief Initialize an RSA-alt context
404 *
405 * \param ctx Context to initialize. It must not have been set
406 * up yet (type #MBEDTLS_PK_NONE).
407 * \param key RSA key pointer
408 * \param decrypt_func Decryption function
409 * \param sign_func Signing function
410 * \param key_len_func Function returning key length in bytes
411 *
412 * \return 0 on success, or MBEDTLS_ERR_PK_BAD_INPUT_DATA if the
413 * context wasn't already initialized as RSA_ALT.
414 *
415 * \note This function replaces \c mbedtls_pk_setup() for RSA-alt.
416 */
417 int mbedtls_pk_setup_rsa_alt(mbedtls_pk_context *ctx, void *key,
418 mbedtls_pk_rsa_alt_decrypt_func decrypt_func,
419 mbedtls_pk_rsa_alt_sign_func sign_func,
420 mbedtls_pk_rsa_alt_key_len_func key_len_func);
421 #endif /* MBEDTLS_PK_RSA_ALT_SUPPORT */
422
423 /**
424 * \brief Get the size in bits of the underlying key
425 *
426 * \param ctx The context to query. It must have been initialized.
427 *
428 * \return Key size in bits, or 0 on error
429 */
430 size_t mbedtls_pk_get_bitlen(const mbedtls_pk_context *ctx);
431
432 /**
433 * \brief Get the length in bytes of the underlying key
434 *
435 * \param ctx The context to query. It must have been initialized.
436 *
437 * \return Key length in bytes, or 0 on error
438 */
mbedtls_pk_get_len(const mbedtls_pk_context * ctx)439 static inline size_t mbedtls_pk_get_len(const mbedtls_pk_context *ctx)
440 {
441 return (mbedtls_pk_get_bitlen(ctx) + 7) / 8;
442 }
443
444 /**
445 * \brief Tell if a context can do the operation given by type
446 *
447 * \param ctx The context to query. It must have been initialized.
448 * \param type The desired type.
449 *
450 * \return 1 if the context can do operations on the given type.
451 * \return 0 if the context cannot do the operations on the given
452 * type. This is always the case for a context that has
453 * been initialized but not set up, or that has been
454 * cleared with mbedtls_pk_free().
455 */
456 int mbedtls_pk_can_do(const mbedtls_pk_context *ctx, mbedtls_pk_type_t type);
457
458 #if defined(MBEDTLS_USE_PSA_CRYPTO)
459 /**
460 * \brief Tell if context can do the operation given by PSA algorithm
461 *
462 * \param ctx The context to query. It must have been initialized.
463 * \param alg PSA algorithm to check against, the following are allowed:
464 * PSA_ALG_RSA_PKCS1V15_SIGN(hash),
465 * PSA_ALG_RSA_PSS(hash),
466 * PSA_ALG_RSA_PKCS1V15_CRYPT,
467 * PSA_ALG_ECDSA(hash),
468 * PSA_ALG_ECDH, where hash is a specific hash.
469 * \param usage PSA usage flag to check against, must be composed of:
470 * PSA_KEY_USAGE_SIGN_HASH
471 * PSA_KEY_USAGE_DECRYPT
472 * PSA_KEY_USAGE_DERIVE.
473 * Context key must match all passed usage flags.
474 *
475 * \warning Since the set of allowed algorithms and usage flags may be
476 * expanded in the future, the return value \c 0 should not
477 * be taken in account for non-allowed algorithms and usage
478 * flags.
479 *
480 * \return 1 if the context can do operations on the given type.
481 * \return 0 if the context cannot do the operations on the given
482 * type, for non-allowed algorithms and usage flags, or
483 * for a context that has been initialized but not set up
484 * or that has been cleared with mbedtls_pk_free().
485 */
486 int mbedtls_pk_can_do_ext(const mbedtls_pk_context *ctx, psa_algorithm_t alg,
487 psa_key_usage_t usage);
488 #endif /* MBEDTLS_USE_PSA_CRYPTO */
489
490 #if defined(MBEDTLS_PSA_CRYPTO_CLIENT)
491 /**
492 * \brief Determine valid PSA attributes that can be used to
493 * import a key into PSA.
494 *
495 * The attributes determined by this function are suitable
496 * for calling mbedtls_pk_import_into_psa() to create
497 * a PSA key with the same key material.
498 *
499 * The typical flow of operations involving this function is
500 * ```
501 * psa_key_attributes_t attributes = PSA_KEY_ATTRIBUTES_INIT;
502 * int ret = mbedtls_pk_get_psa_attributes(pk, &attributes);
503 * if (ret != 0) ...; // error handling omitted
504 * // Tweak attributes if desired
505 * psa_key_id_t key_id = 0;
506 * ret = mbedtls_pk_import_into_psa(pk, &attributes, &key_id);
507 * if (ret != 0) ...; // error handling omitted
508 * ```
509 *
510 * \note This function does not support RSA-alt contexts
511 * (set up with mbedtls_pk_setup_rsa_alt()).
512 *
513 * \param[in] pk The PK context to use. It must have been set up.
514 * It can either contain a key pair or just a public key.
515 * \param usage A single `PSA_KEY_USAGE_xxx` flag among the following:
516 * - #PSA_KEY_USAGE_DECRYPT: \p pk must contain a
517 * key pair. The output \p attributes will contain a
518 * key pair type, and the usage policy will allow
519 * #PSA_KEY_USAGE_ENCRYPT as well as
520 * #PSA_KEY_USAGE_DECRYPT.
521 * - #PSA_KEY_USAGE_DERIVE: \p pk must contain a
522 * key pair. The output \p attributes will contain a
523 * key pair type.
524 * - #PSA_KEY_USAGE_ENCRYPT: The output
525 * \p attributes will contain a public key type.
526 * - #PSA_KEY_USAGE_SIGN_HASH: \p pk must contain a
527 * key pair. The output \p attributes will contain a
528 * key pair type, and the usage policy will allow
529 * #PSA_KEY_USAGE_VERIFY_HASH as well as
530 * #PSA_KEY_USAGE_SIGN_HASH.
531 * - #PSA_KEY_USAGE_SIGN_MESSAGE: \p pk must contain a
532 * key pair. The output \p attributes will contain a
533 * key pair type, and the usage policy will allow
534 * #PSA_KEY_USAGE_VERIFY_MESSAGE as well as
535 * #PSA_KEY_USAGE_SIGN_MESSAGE.
536 * - #PSA_KEY_USAGE_VERIFY_HASH: The output
537 * \p attributes will contain a public key type.
538 * - #PSA_KEY_USAGE_VERIFY_MESSAGE: The output
539 * \p attributes will contain a public key type.
540 * \param[out] attributes
541 * On success, valid attributes to import the key into PSA.
542 * - The lifetime and key identifier are unchanged. If the
543 * attribute structure was initialized or reset before
544 * calling this function, this will result in a volatile
545 * key. Call psa_set_key_identifier() before or after this
546 * function if you wish to create a persistent key. Call
547 * psa_set_key_lifetime() before or after this function if
548 * you wish to import the key in a secure element.
549 * - The key type and bit-size are determined by the contents
550 * of the PK context. If the PK context contains a key
551 * pair, the key type can be either a key pair type or
552 * the corresponding public key type, depending on
553 * \p usage. If the PK context contains a public key,
554 * the key type is a public key type.
555 * - The key's policy is determined by the key type and
556 * the \p usage parameter. The usage always allows
557 * \p usage, exporting and copying the key, and
558 * possibly other permissions as documented for the
559 * \p usage parameter.
560 * The permitted algorithm policy is determined as follows
561 * based on the #mbedtls_pk_type_t type of \p pk,
562 * the chosen \p usage and other factors:
563 * - #MBEDTLS_PK_RSA whose underlying
564 * #mbedtls_rsa_context has the padding mode
565 * #MBEDTLS_RSA_PKCS_V15:
566 * #PSA_ALG_RSA_PKCS1V15_SIGN(#PSA_ALG_ANY_HASH)
567 * if \p usage is SIGN/VERIFY, and
568 * #PSA_ALG_RSA_PKCS1V15_CRYPT
569 * if \p usage is ENCRYPT/DECRYPT.
570 * - #MBEDTLS_PK_RSA whose underlying
571 * #mbedtls_rsa_context has the padding mode
572 * #MBEDTLS_RSA_PKCS_V21 and the digest type
573 * corresponding to the PSA algorithm \c hash:
574 * #PSA_ALG_RSA_PSS_ANY_SALT(#PSA_ALG_ANY_HASH)
575 * if \p usage is SIGN/VERIFY, and
576 * #PSA_ALG_RSA_OAEP(\c hash)
577 * if \p usage is ENCRYPT/DECRYPT.
578 * - #MBEDTLS_PK_RSA_ALT: not supported.
579 * - #MBEDTLS_PK_ECDSA or #MBEDTLS_PK_ECKEY
580 * if \p usage is SIGN/VERIFY:
581 * #PSA_ALG_DETERMINISTIC_ECDSA(#PSA_ALG_ANY_HASH)
582 * if #MBEDTLS_ECDSA_DETERMINISTIC is enabled,
583 * otherwise #PSA_ALG_ECDSA(#PSA_ALG_ANY_HASH).
584 * - #MBEDTLS_PK_ECKEY_DH or #MBEDTLS_PK_ECKEY
585 * if \p usage is DERIVE:
586 * #PSA_ALG_ECDH.
587 * - #MBEDTLS_PK_OPAQUE: same as the primary algorithm
588 * set for the underlying PSA key, except that
589 * sign/decrypt flags are removed if the type is
590 * set to a public key type.
591 * The underlying key must allow \p usage.
592 * Note that the enrollment algorithm set with
593 * psa_set_key_enrollment_algorithm() is not copied.
594 *
595 * \return 0 on success.
596 * #MBEDTLS_ERR_PK_TYPE_MISMATCH if \p pk does not contain
597 * a key of the type identified in \p attributes.
598 * Another error code on other failures.
599 */
600 int mbedtls_pk_get_psa_attributes(const mbedtls_pk_context *pk,
601 psa_key_usage_t usage,
602 psa_key_attributes_t *attributes);
603
604 /**
605 * \brief Import a key into the PSA key store.
606 *
607 * This function is equivalent to calling psa_import_key()
608 * with the key material from \p pk.
609 *
610 * The typical way to use this function is:
611 * -# Call mbedtls_pk_get_psa_attributes() to obtain
612 * attributes for the given key.
613 * -# If desired, modify the attributes, for example:
614 * - To create a persistent key, call
615 * psa_set_key_identifier() and optionally
616 * psa_set_key_lifetime().
617 * - To import only the public part of a key pair:
618 *
619 * psa_set_key_type(&attributes,
620 * PSA_KEY_TYPE_PUBLIC_KEY_OF_KEY_PAIR(
621 * psa_get_key_type(&attributes)));
622 * - Restrict the key usage if desired.
623 * -# Call mbedtls_pk_import_into_psa().
624 *
625 * \note This function does not support RSA-alt contexts
626 * (set up with mbedtls_pk_setup_rsa_alt()).
627 *
628 * \param[in] pk The PK context to use. It must have been set up.
629 * It can either contain a key pair or just a public key.
630 * \param[in] attributes
631 * The attributes to use for the new key. They must be
632 * compatible with \p pk. In particular, the key type
633 * must match the content of \p pk.
634 * If \p pk contains a key pair, the key type in
635 * attributes can be either the key pair type or the
636 * corresponding public key type (to import only the
637 * public part).
638 * \param[out] key_id
639 * On success, the identifier of the newly created key.
640 * On error, this is #MBEDTLS_SVC_KEY_ID_INIT.
641 *
642 * \return 0 on success.
643 * #MBEDTLS_ERR_PK_TYPE_MISMATCH if \p pk does not contain
644 * a key of the type identified in \p attributes.
645 * Another error code on other failures.
646 */
647 int mbedtls_pk_import_into_psa(const mbedtls_pk_context *pk,
648 const psa_key_attributes_t *attributes,
649 mbedtls_svc_key_id_t *key_id);
650
651 /**
652 * \brief Create a PK context starting from a key stored in PSA.
653 * This key:
654 * - must be exportable and
655 * - must be an RSA or EC key pair or public key (FFDH is not supported in PK).
656 *
657 * The resulting PK object will be a transparent type:
658 * - #MBEDTLS_PK_RSA for RSA keys or
659 * - #MBEDTLS_PK_ECKEY for EC keys.
660 *
661 * Once this functions returns the PK object will be completely
662 * independent from the original PSA key that it was generated
663 * from.
664 * Calling mbedtls_pk_sign(), mbedtls_pk_verify(),
665 * mbedtls_pk_encrypt(), mbedtls_pk_decrypt() on the resulting
666 * PK context will perform the corresponding algorithm for that
667 * PK context type.
668 * * For ECDSA, the choice of deterministic vs randomized will
669 * be based on the compile-time setting #MBEDTLS_ECDSA_DETERMINISTIC.
670 * * For an RSA key, the output PK context will allow both
671 * encrypt/decrypt and sign/verify regardless of the original
672 * key's policy.
673 * The original key's policy determines the output key's padding
674 * mode: PCKS1 v2.1 is set if the PSA key policy is OAEP or PSS,
675 * otherwise PKCS1 v1.5 is set.
676 *
677 * \param key_id The key identifier of the key stored in PSA.
678 * \param pk The PK context that will be filled. It must be initialized,
679 * but not set up.
680 *
681 * \return 0 on success.
682 * \return #MBEDTLS_ERR_PK_BAD_INPUT_DATA in case the provided input
683 * parameters are not correct.
684 */
685 int mbedtls_pk_copy_from_psa(mbedtls_svc_key_id_t key_id, mbedtls_pk_context *pk);
686
687 /**
688 * \brief Create a PK context for the public key of a PSA key.
689 *
690 * The key must be an RSA or ECC key. It can be either a
691 * public key or a key pair, and only the public key is copied.
692 * The resulting PK object will be a transparent type:
693 * - #MBEDTLS_PK_RSA for RSA keys or
694 * - #MBEDTLS_PK_ECKEY for EC keys.
695 *
696 * Once this functions returns the PK object will be completely
697 * independent from the original PSA key that it was generated
698 * from.
699 * Calling mbedtls_pk_verify() or
700 * mbedtls_pk_encrypt() on the resulting
701 * PK context will perform the corresponding algorithm for that
702 * PK context type.
703 *
704 * For an RSA key, the output PK context will allow both
705 * encrypt and verify regardless of the original key's policy.
706 * The original key's policy determines the output key's padding
707 * mode: PCKS1 v2.1 is set if the PSA key policy is OAEP or PSS,
708 * otherwise PKCS1 v1.5 is set.
709 *
710 * \param key_id The key identifier of the key stored in PSA.
711 * \param pk The PK context that will be filled. It must be initialized,
712 * but not set up.
713 *
714 * \return 0 on success.
715 * \return MBEDTLS_ERR_PK_BAD_INPUT_DATA in case the provided input
716 * parameters are not correct.
717 */
718 int mbedtls_pk_copy_public_from_psa(mbedtls_svc_key_id_t key_id, mbedtls_pk_context *pk);
719 #endif /* MBEDTLS_PSA_CRYPTO_CLIENT */
720
721 /**
722 * \brief Verify signature (including padding if relevant).
723 *
724 * \param ctx The PK context to use. It must have been set up.
725 * \param md_alg Hash algorithm used.
726 * This can be #MBEDTLS_MD_NONE if the signature algorithm
727 * does not rely on a hash algorithm (non-deterministic
728 * ECDSA, RSA PKCS#1 v1.5).
729 * For PKCS#1 v1.5, if \p md_alg is #MBEDTLS_MD_NONE, then
730 * \p hash is the DigestInfo structure used by RFC 8017
731 * §9.2 steps 3–6. If \p md_alg is a valid hash
732 * algorithm then \p hash is the digest itself, and this
733 * function calculates the DigestInfo encoding internally.
734 * \param hash Hash of the message to sign
735 * \param hash_len Hash length
736 * \param sig Signature to verify
737 * \param sig_len Signature length
738 *
739 * \note For keys of type #MBEDTLS_PK_RSA, the signature algorithm is
740 * either PKCS#1 v1.5 or PSS (accepting any salt length),
741 * depending on the padding mode in the underlying RSA context.
742 * For a pk object constructed by parsing, this is PKCS#1 v1.5
743 * by default. Use mbedtls_pk_verify_ext() to explicitly select
744 * a different algorithm.
745 *
746 * \return 0 on success (signature is valid),
747 * #MBEDTLS_ERR_PK_SIG_LEN_MISMATCH if there is a valid
748 * signature in \p sig but its length is less than \p sig_len,
749 * or a specific error code.
750 */
751 int mbedtls_pk_verify(mbedtls_pk_context *ctx, mbedtls_md_type_t md_alg,
752 const unsigned char *hash, size_t hash_len,
753 const unsigned char *sig, size_t sig_len);
754
755 /**
756 * \brief Restartable version of \c mbedtls_pk_verify()
757 *
758 * \note Performs the same job as \c mbedtls_pk_verify(), but can
759 * return early and restart according to the limit set with
760 * \c mbedtls_ecp_set_max_ops() to reduce blocking for ECC
761 * operations. For RSA, same as \c mbedtls_pk_verify().
762 *
763 * \param ctx The PK context to use. It must have been set up.
764 * \param md_alg Hash algorithm used (see notes)
765 * \param hash Hash of the message to sign
766 * \param hash_len Hash length or 0 (see notes)
767 * \param sig Signature to verify
768 * \param sig_len Signature length
769 * \param rs_ctx Restart context (NULL to disable restart)
770 *
771 * \return See \c mbedtls_pk_verify(), or
772 * \return #MBEDTLS_ERR_ECP_IN_PROGRESS if maximum number of
773 * operations was reached: see \c mbedtls_ecp_set_max_ops().
774 */
775 int mbedtls_pk_verify_restartable(mbedtls_pk_context *ctx,
776 mbedtls_md_type_t md_alg,
777 const unsigned char *hash, size_t hash_len,
778 const unsigned char *sig, size_t sig_len,
779 mbedtls_pk_restart_ctx *rs_ctx);
780
781 /**
782 * \brief Verify signature, with options.
783 * (Includes verification of the padding depending on type.)
784 *
785 * \param type Signature type (inc. possible padding type) to verify
786 * \param options Pointer to type-specific options, or NULL
787 * \param ctx The PK context to use. It must have been set up.
788 * \param md_alg Hash algorithm used (see notes)
789 * \param hash Hash of the message to sign
790 * \param hash_len Hash length or 0 (see notes)
791 * \param sig Signature to verify
792 * \param sig_len Signature length
793 *
794 * \return 0 on success (signature is valid),
795 * #MBEDTLS_ERR_PK_TYPE_MISMATCH if the PK context can't be
796 * used for this type of signatures,
797 * #MBEDTLS_ERR_PK_SIG_LEN_MISMATCH if there is a valid
798 * signature in \p sig but its length is less than \p sig_len,
799 * or a specific error code.
800 *
801 * \note If hash_len is 0, then the length associated with md_alg
802 * is used instead, or an error returned if it is invalid.
803 *
804 * \note md_alg may be MBEDTLS_MD_NONE, only if hash_len != 0
805 *
806 * \note If type is MBEDTLS_PK_RSASSA_PSS, then options must point
807 * to a mbedtls_pk_rsassa_pss_options structure,
808 * otherwise it must be NULL. Note that if
809 * #MBEDTLS_USE_PSA_CRYPTO is defined, the salt length is not
810 * verified as PSA_ALG_RSA_PSS_ANY_SALT is used.
811 */
812 int mbedtls_pk_verify_ext(mbedtls_pk_type_t type, const void *options,
813 mbedtls_pk_context *ctx, mbedtls_md_type_t md_alg,
814 const unsigned char *hash, size_t hash_len,
815 const unsigned char *sig, size_t sig_len);
816
817 /**
818 * \brief Make signature, including padding if relevant.
819 *
820 * \param ctx The PK context to use. It must have been set up
821 * with a private key.
822 * \param md_alg Hash algorithm used (see notes)
823 * \param hash Hash of the message to sign
824 * \param hash_len Hash length
825 * \param sig Place to write the signature.
826 * It must have enough room for the signature.
827 * #MBEDTLS_PK_SIGNATURE_MAX_SIZE is always enough.
828 * You may use a smaller buffer if it is large enough
829 * given the key type.
830 * \param sig_size The size of the \p sig buffer in bytes.
831 * \param sig_len On successful return,
832 * the number of bytes written to \p sig.
833 * \param f_rng RNG function, must not be \c NULL.
834 * \param p_rng RNG parameter
835 *
836 * \note For keys of type #MBEDTLS_PK_RSA, the signature algorithm is
837 * either PKCS#1 v1.5 or PSS (using the largest possible salt
838 * length up to the hash length), depending on the padding mode
839 * in the underlying RSA context. For a pk object constructed
840 * by parsing, this is PKCS#1 v1.5 by default. Use
841 * mbedtls_pk_verify_ext() to explicitly select a different
842 * algorithm.
843 *
844 * \return 0 on success, or a specific error code.
845 *
846 * \note For RSA, md_alg may be MBEDTLS_MD_NONE if hash_len != 0.
847 * For ECDSA, md_alg may never be MBEDTLS_MD_NONE.
848 */
849 int mbedtls_pk_sign(mbedtls_pk_context *ctx, mbedtls_md_type_t md_alg,
850 const unsigned char *hash, size_t hash_len,
851 unsigned char *sig, size_t sig_size, size_t *sig_len,
852 int (*f_rng)(void *, unsigned char *, size_t), void *p_rng);
853
854 /**
855 * \brief Make signature given a signature type.
856 *
857 * \param pk_type Signature type.
858 * \param ctx The PK context to use. It must have been set up
859 * with a private key.
860 * \param md_alg Hash algorithm used (see notes)
861 * \param hash Hash of the message to sign
862 * \param hash_len Hash length
863 * \param sig Place to write the signature.
864 * It must have enough room for the signature.
865 * #MBEDTLS_PK_SIGNATURE_MAX_SIZE is always enough.
866 * You may use a smaller buffer if it is large enough
867 * given the key type.
868 * \param sig_size The size of the \p sig buffer in bytes.
869 * \param sig_len On successful return,
870 * the number of bytes written to \p sig.
871 * \param f_rng RNG function, must not be \c NULL.
872 * \param p_rng RNG parameter
873 *
874 * \return 0 on success, or a specific error code.
875 *
876 * \note When \p pk_type is #MBEDTLS_PK_RSASSA_PSS,
877 * see #PSA_ALG_RSA_PSS for a description of PSS options used.
878 *
879 * \note For RSA, md_alg may be MBEDTLS_MD_NONE if hash_len != 0.
880 * For ECDSA, md_alg may never be MBEDTLS_MD_NONE.
881 *
882 */
883 int mbedtls_pk_sign_ext(mbedtls_pk_type_t pk_type,
884 mbedtls_pk_context *ctx,
885 mbedtls_md_type_t md_alg,
886 const unsigned char *hash, size_t hash_len,
887 unsigned char *sig, size_t sig_size, size_t *sig_len,
888 int (*f_rng)(void *, unsigned char *, size_t),
889 void *p_rng);
890
891 /**
892 * \brief Restartable version of \c mbedtls_pk_sign()
893 *
894 * \note Performs the same job as \c mbedtls_pk_sign(), but can
895 * return early and restart according to the limit set with
896 * \c mbedtls_ecp_set_max_ops() to reduce blocking for ECC
897 * operations. For RSA, same as \c mbedtls_pk_sign().
898 *
899 * \param ctx The PK context to use. It must have been set up
900 * with a private key.
901 * \param md_alg Hash algorithm used (see notes for mbedtls_pk_sign())
902 * \param hash Hash of the message to sign
903 * \param hash_len Hash length
904 * \param sig Place to write the signature.
905 * It must have enough room for the signature.
906 * #MBEDTLS_PK_SIGNATURE_MAX_SIZE is always enough.
907 * You may use a smaller buffer if it is large enough
908 * given the key type.
909 * \param sig_size The size of the \p sig buffer in bytes.
910 * \param sig_len On successful return,
911 * the number of bytes written to \p sig.
912 * \param f_rng RNG function, must not be \c NULL.
913 * \param p_rng RNG parameter
914 * \param rs_ctx Restart context (NULL to disable restart)
915 *
916 * \return See \c mbedtls_pk_sign().
917 * \return #MBEDTLS_ERR_ECP_IN_PROGRESS if maximum number of
918 * operations was reached: see \c mbedtls_ecp_set_max_ops().
919 */
920 int mbedtls_pk_sign_restartable(mbedtls_pk_context *ctx,
921 mbedtls_md_type_t md_alg,
922 const unsigned char *hash, size_t hash_len,
923 unsigned char *sig, size_t sig_size, size_t *sig_len,
924 int (*f_rng)(void *, unsigned char *, size_t), void *p_rng,
925 mbedtls_pk_restart_ctx *rs_ctx);
926
927 /**
928 * \brief Decrypt message (including padding if relevant).
929 *
930 * \param ctx The PK context to use. It must have been set up
931 * with a private key.
932 * \param input Input to decrypt
933 * \param ilen Input size
934 * \param output Decrypted output
935 * \param olen Decrypted message length
936 * \param osize Size of the output buffer
937 * \param f_rng RNG function, must not be \c NULL.
938 * \param p_rng RNG parameter
939 *
940 * \note For keys of type #MBEDTLS_PK_RSA, the signature algorithm is
941 * either PKCS#1 v1.5 or OAEP, depending on the padding mode in
942 * the underlying RSA context. For a pk object constructed by
943 * parsing, this is PKCS#1 v1.5 by default.
944 *
945 * \return 0 on success, or a specific error code.
946 */
947 int mbedtls_pk_decrypt(mbedtls_pk_context *ctx,
948 const unsigned char *input, size_t ilen,
949 unsigned char *output, size_t *olen, size_t osize,
950 int (*f_rng)(void *, unsigned char *, size_t), void *p_rng);
951
952 /**
953 * \brief Encrypt message (including padding if relevant).
954 *
955 * \param ctx The PK context to use. It must have been set up.
956 * \param input Message to encrypt
957 * \param ilen Message size
958 * \param output Encrypted output
959 * \param olen Encrypted output length
960 * \param osize Size of the output buffer
961 * \param f_rng RNG function, must not be \c NULL.
962 * \param p_rng RNG parameter
963 *
964 * \note For keys of type #MBEDTLS_PK_RSA, the signature algorithm is
965 * either PKCS#1 v1.5 or OAEP, depending on the padding mode in
966 * the underlying RSA context. For a pk object constructed by
967 * parsing, this is PKCS#1 v1.5 by default.
968 *
969 * \note \p f_rng is used for padding generation.
970 *
971 * \return 0 on success, or a specific error code.
972 */
973 int mbedtls_pk_encrypt(mbedtls_pk_context *ctx,
974 const unsigned char *input, size_t ilen,
975 unsigned char *output, size_t *olen, size_t osize,
976 int (*f_rng)(void *, unsigned char *, size_t), void *p_rng);
977
978 /**
979 * \brief Check if a public-private pair of keys matches.
980 *
981 * \param pub Context holding a public key.
982 * \param prv Context holding a private (and public) key.
983 * \param f_rng RNG function, must not be \c NULL.
984 * \param p_rng RNG parameter
985 *
986 * \return \c 0 on success (keys were checked and match each other).
987 * \return #MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE if the keys could not
988 * be checked - in that case they may or may not match.
989 * \return #MBEDTLS_ERR_PK_BAD_INPUT_DATA if a context is invalid.
990 * \return Another non-zero value if the keys do not match.
991 */
992 int mbedtls_pk_check_pair(const mbedtls_pk_context *pub,
993 const mbedtls_pk_context *prv,
994 int (*f_rng)(void *, unsigned char *, size_t),
995 void *p_rng);
996
997 /**
998 * \brief Export debug information
999 *
1000 * \param ctx The PK context to use. It must have been initialized.
1001 * \param items Place to write debug items
1002 *
1003 * \return 0 on success or MBEDTLS_ERR_PK_BAD_INPUT_DATA
1004 */
1005 int mbedtls_pk_debug(const mbedtls_pk_context *ctx, mbedtls_pk_debug_item *items);
1006
1007 /**
1008 * \brief Access the type name
1009 *
1010 * \param ctx The PK context to use. It must have been initialized.
1011 *
1012 * \return Type name on success, or "invalid PK"
1013 */
1014 const char *mbedtls_pk_get_name(const mbedtls_pk_context *ctx);
1015
1016 /**
1017 * \brief Get the key type
1018 *
1019 * \param ctx The PK context to use. It must have been initialized.
1020 *
1021 * \return Type on success.
1022 * \return #MBEDTLS_PK_NONE for a context that has not been set up.
1023 */
1024 mbedtls_pk_type_t mbedtls_pk_get_type(const mbedtls_pk_context *ctx);
1025
1026 #if defined(MBEDTLS_RSA_C)
1027 /**
1028 * Quick access to an RSA context inside a PK context.
1029 *
1030 * \warning This function can only be used when the type of the context, as
1031 * returned by mbedtls_pk_get_type(), is #MBEDTLS_PK_RSA.
1032 * Ensuring that is the caller's responsibility.
1033 * Alternatively, you can check whether this function returns NULL.
1034 *
1035 * \return The internal RSA context held by the PK context, or NULL.
1036 */
mbedtls_pk_rsa(const mbedtls_pk_context pk)1037 static inline mbedtls_rsa_context *mbedtls_pk_rsa(const mbedtls_pk_context pk)
1038 {
1039 switch (mbedtls_pk_get_type(&pk)) {
1040 case MBEDTLS_PK_RSA:
1041 return (mbedtls_rsa_context *) (pk).MBEDTLS_PRIVATE(pk_ctx);
1042 default:
1043 return NULL;
1044 }
1045 }
1046 #endif /* MBEDTLS_RSA_C */
1047
1048 #if defined(MBEDTLS_ECP_C)
1049 /**
1050 * Quick access to an EC context inside a PK context.
1051 *
1052 * \warning This function can only be used when the type of the context, as
1053 * returned by mbedtls_pk_get_type(), is #MBEDTLS_PK_ECKEY,
1054 * #MBEDTLS_PK_ECKEY_DH, or #MBEDTLS_PK_ECDSA.
1055 * Ensuring that is the caller's responsibility.
1056 * Alternatively, you can check whether this function returns NULL.
1057 *
1058 * \return The internal EC context held by the PK context, or NULL.
1059 */
mbedtls_pk_ec(const mbedtls_pk_context pk)1060 static inline mbedtls_ecp_keypair *mbedtls_pk_ec(const mbedtls_pk_context pk)
1061 {
1062 switch (mbedtls_pk_get_type(&pk)) {
1063 case MBEDTLS_PK_ECKEY:
1064 case MBEDTLS_PK_ECKEY_DH:
1065 case MBEDTLS_PK_ECDSA:
1066 return (mbedtls_ecp_keypair *) (pk).MBEDTLS_PRIVATE(pk_ctx);
1067 default:
1068 return NULL;
1069 }
1070 }
1071 #endif /* MBEDTLS_ECP_C */
1072
1073 #if defined(MBEDTLS_PK_PARSE_C)
1074 /** \ingroup pk_module */
1075 /**
1076 * \brief Parse a private key in PEM or DER format
1077 *
1078 * \note If #MBEDTLS_USE_PSA_CRYPTO is enabled, the PSA crypto
1079 * subsystem must have been initialized by calling
1080 * psa_crypto_init() before calling this function.
1081 *
1082 * \param ctx The PK context to fill. It must have been initialized
1083 * but not set up.
1084 * \param key Input buffer to parse.
1085 * The buffer must contain the input exactly, with no
1086 * extra trailing material. For PEM, the buffer must
1087 * contain a null-terminated string.
1088 * \param keylen Size of \b key in bytes.
1089 * For PEM data, this includes the terminating null byte,
1090 * so \p keylen must be equal to `strlen(key) + 1`.
1091 * \param pwd Optional password for decryption.
1092 * Pass \c NULL if expecting a non-encrypted key.
1093 * Pass a string of \p pwdlen bytes if expecting an encrypted
1094 * key; a non-encrypted key will also be accepted.
1095 * The empty password is not supported.
1096 * \param pwdlen Size of the password in bytes.
1097 * Ignored if \p pwd is \c NULL.
1098 * \param f_rng RNG function, must not be \c NULL. Used for blinding.
1099 * \param p_rng RNG parameter
1100 *
1101 * \note On entry, ctx must be empty, either freshly initialised
1102 * with mbedtls_pk_init() or reset with mbedtls_pk_free(). If you need a
1103 * specific key type, check the result with mbedtls_pk_can_do().
1104 *
1105 * \note The key is also checked for correctness.
1106 *
1107 * \return 0 if successful, or a specific PK or PEM error code
1108 */
1109 int mbedtls_pk_parse_key(mbedtls_pk_context *ctx,
1110 const unsigned char *key, size_t keylen,
1111 const unsigned char *pwd, size_t pwdlen,
1112 int (*f_rng)(void *, unsigned char *, size_t), void *p_rng);
1113
1114 /** \ingroup pk_module */
1115 /**
1116 * \brief Parse a public key in PEM or DER format
1117 *
1118 * \note If #MBEDTLS_USE_PSA_CRYPTO is enabled, the PSA crypto
1119 * subsystem must have been initialized by calling
1120 * psa_crypto_init() before calling this function.
1121 *
1122 * \param ctx The PK context to fill. It must have been initialized
1123 * but not set up.
1124 * \param key Input buffer to parse.
1125 * The buffer must contain the input exactly, with no
1126 * extra trailing material. For PEM, the buffer must
1127 * contain a null-terminated string.
1128 * \param keylen Size of \b key in bytes.
1129 * For PEM data, this includes the terminating null byte,
1130 * so \p keylen must be equal to `strlen(key) + 1`.
1131 *
1132 * \note On entry, ctx must be empty, either freshly initialised
1133 * with mbedtls_pk_init() or reset with mbedtls_pk_free(). If you need a
1134 * specific key type, check the result with mbedtls_pk_can_do().
1135 *
1136 * \note For compressed points, see #MBEDTLS_ECP_PF_COMPRESSED for
1137 * limitations.
1138 *
1139 * \note The key is also checked for correctness.
1140 *
1141 * \return 0 if successful, or a specific PK or PEM error code
1142 */
1143 int mbedtls_pk_parse_public_key(mbedtls_pk_context *ctx,
1144 const unsigned char *key, size_t keylen);
1145
1146 #if defined(MBEDTLS_FS_IO)
1147 /** \ingroup pk_module */
1148 /**
1149 * \brief Load and parse a private key
1150 *
1151 * \note If #MBEDTLS_USE_PSA_CRYPTO is enabled, the PSA crypto
1152 * subsystem must have been initialized by calling
1153 * psa_crypto_init() before calling this function.
1154 *
1155 * \param ctx The PK context to fill. It must have been initialized
1156 * but not set up.
1157 * \param path filename to read the private key from
1158 * \param password Optional password to decrypt the file.
1159 * Pass \c NULL if expecting a non-encrypted key.
1160 * Pass a null-terminated string if expecting an encrypted
1161 * key; a non-encrypted key will also be accepted.
1162 * The empty password is not supported.
1163 * \param f_rng RNG function, must not be \c NULL. Used for blinding.
1164 * \param p_rng RNG parameter
1165 *
1166 * \note On entry, ctx must be empty, either freshly initialised
1167 * with mbedtls_pk_init() or reset with mbedtls_pk_free(). If you need a
1168 * specific key type, check the result with mbedtls_pk_can_do().
1169 *
1170 * \note The key is also checked for correctness.
1171 *
1172 * \return 0 if successful, or a specific PK or PEM error code
1173 */
1174 int mbedtls_pk_parse_keyfile(mbedtls_pk_context *ctx,
1175 const char *path, const char *password,
1176 int (*f_rng)(void *, unsigned char *, size_t), void *p_rng);
1177
1178 /** \ingroup pk_module */
1179 /**
1180 * \brief Load and parse a public key
1181 *
1182 * \param ctx The PK context to fill. It must have been initialized
1183 * but not set up.
1184 * \param path filename to read the public key from
1185 *
1186 * \note On entry, ctx must be empty, either freshly initialised
1187 * with mbedtls_pk_init() or reset with mbedtls_pk_free(). If
1188 * you need a specific key type, check the result with
1189 * mbedtls_pk_can_do().
1190 *
1191 * \note The key is also checked for correctness.
1192 *
1193 * \return 0 if successful, or a specific PK or PEM error code
1194 */
1195 int mbedtls_pk_parse_public_keyfile(mbedtls_pk_context *ctx, const char *path);
1196 #endif /* MBEDTLS_FS_IO */
1197 #endif /* MBEDTLS_PK_PARSE_C */
1198
1199 #if defined(MBEDTLS_PK_WRITE_C)
1200 /**
1201 * \brief Write a private key to a PKCS#1 or SEC1 DER structure
1202 * Note: data is written at the end of the buffer! Use the
1203 * return value to determine where you should start
1204 * using the buffer
1205 *
1206 * \param ctx PK context which must contain a valid private key.
1207 * \param buf buffer to write to
1208 * \param size size of the buffer
1209 *
1210 * \return length of data written if successful, or a specific
1211 * error code
1212 */
1213 int mbedtls_pk_write_key_der(const mbedtls_pk_context *ctx, unsigned char *buf, size_t size);
1214
1215 /**
1216 * \brief Write a public key to a SubjectPublicKeyInfo DER structure
1217 * Note: data is written at the end of the buffer! Use the
1218 * return value to determine where you should start
1219 * using the buffer
1220 *
1221 * \param ctx PK context which must contain a valid public or private key.
1222 * \param buf buffer to write to
1223 * \param size size of the buffer
1224 *
1225 * \return length of data written if successful, or a specific
1226 * error code
1227 */
1228 int mbedtls_pk_write_pubkey_der(const mbedtls_pk_context *ctx, unsigned char *buf, size_t size);
1229
1230 #if defined(MBEDTLS_PEM_WRITE_C)
1231 /**
1232 * \brief Write a public key to a PEM string
1233 *
1234 * \param ctx PK context which must contain a valid public or private key.
1235 * \param buf Buffer to write to. The output includes a
1236 * terminating null byte.
1237 * \param size Size of the buffer in bytes.
1238 *
1239 * \return 0 if successful, or a specific error code
1240 */
1241 int mbedtls_pk_write_pubkey_pem(const mbedtls_pk_context *ctx, unsigned char *buf, size_t size);
1242
1243 /**
1244 * \brief Write a private key to a PKCS#1 or SEC1 PEM string
1245 *
1246 * \param ctx PK context which must contain a valid private key.
1247 * \param buf Buffer to write to. The output includes a
1248 * terminating null byte.
1249 * \param size Size of the buffer in bytes.
1250 *
1251 * \return 0 if successful, or a specific error code
1252 */
1253 int mbedtls_pk_write_key_pem(const mbedtls_pk_context *ctx, unsigned char *buf, size_t size);
1254 #endif /* MBEDTLS_PEM_WRITE_C */
1255 #endif /* MBEDTLS_PK_WRITE_C */
1256
1257 /*
1258 * WARNING: Low-level functions. You probably do not want to use these unless
1259 * you are certain you do ;)
1260 */
1261
1262 #if defined(MBEDTLS_PK_PARSE_C)
1263 /**
1264 * \brief Parse a SubjectPublicKeyInfo DER structure
1265 *
1266 * \param p the position in the ASN.1 data
1267 * \param end end of the buffer
1268 * \param pk The PK context to fill. It must have been initialized
1269 * but not set up.
1270 *
1271 * \return 0 if successful, or a specific PK error code
1272 */
1273 int mbedtls_pk_parse_subpubkey(unsigned char **p, const unsigned char *end,
1274 mbedtls_pk_context *pk);
1275 #endif /* MBEDTLS_PK_PARSE_C */
1276
1277 #if defined(MBEDTLS_PK_WRITE_C)
1278 /**
1279 * \brief Write a subjectPublicKey to ASN.1 data
1280 * Note: function works backwards in data buffer
1281 *
1282 * \param p reference to current position pointer
1283 * \param start start of the buffer (for bounds-checking)
1284 * \param key PK context which must contain a valid public or private key.
1285 *
1286 * \return the length written or a negative error code
1287 */
1288 int mbedtls_pk_write_pubkey(unsigned char **p, unsigned char *start,
1289 const mbedtls_pk_context *key);
1290 #endif /* MBEDTLS_PK_WRITE_C */
1291
1292 #ifdef __cplusplus
1293 }
1294 #endif
1295
1296 #endif /* MBEDTLS_PK_H */
1297
