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Gilles Peskinee59236f2018-01-27 23:32:46 +01001/**
2 * \file psa/crypto_extra.h
3 *
4 * \brief PSA cryptography module: Mbed TLS vendor extensions
Gilles Peskine07c91f52018-06-28 18:02:53 +02005 *
6 * \note This file may not be included directly. Applications must
7 * include psa/crypto.h.
8 *
9 * This file is reserved for vendor-specific definitions.
Gilles Peskinee59236f2018-01-27 23:32:46 +010010 */
11/*
12 * Copyright (C) 2018, ARM Limited, All Rights Reserved
13 * SPDX-License-Identifier: Apache-2.0
14 *
15 * Licensed under the Apache License, Version 2.0 (the "License"); you may
16 * not use this file except in compliance with the License.
17 * You may obtain a copy of the License at
18 *
19 * http://www.apache.org/licenses/LICENSE-2.0
20 *
21 * Unless required by applicable law or agreed to in writing, software
22 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
23 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
24 * See the License for the specific language governing permissions and
25 * limitations under the License.
26 *
27 * This file is part of mbed TLS (https://tls.mbed.org)
28 */
29
30#ifndef PSA_CRYPTO_EXTRA_H
31#define PSA_CRYPTO_EXTRA_H
32
Jaeden Amero81cefed2019-02-25 08:51:27 +000033#include "mbedtls/platform_util.h"
34
Gilles Peskinee59236f2018-01-27 23:32:46 +010035#ifdef __cplusplus
36extern "C" {
37#endif
38
Netanel Gonen2bcd3122018-11-19 11:53:02 +020039/* UID for secure storage seed */
avolinski0d2c2662018-11-21 17:31:07 +020040#define PSA_CRYPTO_ITS_RANDOM_SEED_UID 0xFFFFFF52
Netanel Gonen2bcd3122018-11-19 11:53:02 +020041
Jaeden Amero5e6d24c2019-02-21 10:41:29 +000042/*
43 * Deprecated PSA Crypto error code definitions
44 */
45#if !defined(MBEDTLS_DEPRECATED_REMOVED)
46#define PSA_ERROR_UNKNOWN_ERROR \
47 MBEDTLS_DEPRECATED_NUMERIC_CONSTANT( PSA_ERROR_GENERIC_ERROR )
48#endif
49
50#if !defined(MBEDTLS_DEPRECATED_REMOVED)
51#define PSA_ERROR_OCCUPIED_SLOT \
52 MBEDTLS_DEPRECATED_NUMERIC_CONSTANT( PSA_ERROR_ALREADY_EXISTS )
53#endif
54
55#if !defined(MBEDTLS_DEPRECATED_REMOVED)
56#define PSA_ERROR_EMPTY_SLOT \
57 MBEDTLS_DEPRECATED_NUMERIC_CONSTANT( PSA_ERROR_DOES_NOT_EXIST )
58#endif
59
60#if !defined(MBEDTLS_DEPRECATED_REMOVED)
61#define PSA_ERROR_INSUFFICIENT_CAPACITY \
62 MBEDTLS_DEPRECATED_NUMERIC_CONSTANT( PSA_ERROR_INSUFFICIENT_DATA )
63#endif
64
Gilles Peskine96f0b3b2019-05-10 19:33:38 +020065/** \addtogroup attributes
66 * @{
67 */
68
69/** \brief Declare the enrollment algorithm for a key.
70 *
71 * An operation on a key may indifferently use the algorithm set with
72 * psa_set_key_algorithm() or with this function.
73 *
74 * \param[out] attributes The attribute structure to write to.
75 * \param alg2 A second algorithm that the key may be used
76 * for, in addition to the algorithm set with
77 * psa_set_key_algorithm().
78 *
79 * \warning Setting an enrollment algorithm is not recommended, because
80 * using the same key with different algorithms can allow some
81 * attacks based on arithmetic relations between different
82 * computations made with the same key, or can escalate harmless
83 * side channels into exploitable ones. Use this function only
Gilles Peskinef25c9ec2019-05-22 11:45:59 +020084 * if it is necessary to support a protocol for which it has been
Gilles Peskine96f0b3b2019-05-10 19:33:38 +020085 * verified that the usage of the key with multiple algorithms
86 * is safe.
87 */
88static inline void psa_set_key_enrollment_algorithm(
89 psa_key_attributes_t *attributes,
90 psa_algorithm_t alg2)
91{
Gilles Peskine7e0cff92019-07-30 13:48:52 +020092 attributes->core.policy.alg2 = alg2;
Gilles Peskine96f0b3b2019-05-10 19:33:38 +020093}
94
95/** Retrieve the enrollment algorithm policy from key attributes.
96 *
97 * \param[in] attributes The key attribute structure to query.
98 *
99 * \return The enrollment algorithm stored in the attribute structure.
100 */
101static inline psa_algorithm_t psa_get_key_enrollment_algorithm(
102 const psa_key_attributes_t *attributes)
103{
Gilles Peskine7e0cff92019-07-30 13:48:52 +0200104 return( attributes->core.policy.alg2 );
Gilles Peskine96f0b3b2019-05-10 19:33:38 +0200105}
106
Gilles Peskinec8000c02019-08-02 20:15:51 +0200107#if defined(MBEDTLS_PSA_CRYPTO_SE_C)
108
109/** Retrieve the slot number where a key is stored.
110 *
111 * A slot number is only defined for keys that are stored in a secure
112 * element.
113 *
114 * This information is only useful if the secure element is not entirely
115 * managed through the PSA Cryptography API. It is up to the secure
116 * element driver to decide how PSA slot numbers map to any other interface
117 * that the secure element may have.
118 *
119 * \param[in] attributes The key attribute structure to query.
120 * \param[out] slot_number On success, the slot number containing the key.
121 *
122 * \retval #PSA_SUCCESS
123 * The key is located in a secure element, and \p *slot_number
124 * indicates the slot number that contains it.
125 * \retval #PSA_ERROR_NOT_PERMITTED
126 * The caller is not permitted to query the slot number.
127 * Mbed Crypto currently does not return this error.
128 * \retval #PSA_ERROR_INVALID_ARGUMENT
129 * The key is not located in a secure element.
130 */
131psa_status_t psa_get_key_slot_number(
132 const psa_key_attributes_t *attributes,
133 psa_key_slot_number_t *slot_number );
134
135/** Choose the slot number where a key is stored.
136 *
137 * This function declares a slot number in the specified attribute
138 * structure.
139 *
140 * A slot number is only meaningful for keys that are stored in a secure
141 * element. It is up to the secure element driver to decide how PSA slot
142 * numbers map to any other interface that the secure element may have.
143 *
144 * \note Setting a slot number in key attributes for a key creation can
145 * cause the following errors when creating the key:
146 * - #PSA_ERROR_NOT_SUPPORTED if the selected secure element does
147 * not support choosing a specific slot number.
148 * - #PSA_ERROR_NOT_PERMITTED if the caller is not permitted to
149 * choose slot numbers in general or to choose this specific slot.
150 * - #PSA_ERROR_INVALID_ARGUMENT if the chosen slot number is not
151 * valid in general or not valid for this specific key.
152 * - #PSA_ERROR_ALREADY_EXISTS if there is already a key in the
153 * selected slot.
154 *
155 * \param[out] attributes The attribute structure to write to.
156 * \param slot_number The slot number to set.
157 */
158static inline void psa_set_key_slot_number(
159 psa_key_attributes_t *attributes,
160 psa_key_slot_number_t slot_number )
161{
162 attributes->core.flags |= MBEDTLS_PSA_KA_FLAG_HAS_SLOT_NUMBER;
163 attributes->slot_number = slot_number;
164}
165
166#endif /* MBEDTLS_PSA_CRYPTO_SE_C */
167
Gilles Peskine96f0b3b2019-05-10 19:33:38 +0200168/**@}*/
169
Gilles Peskinee59236f2018-01-27 23:32:46 +0100170/**
171 * \brief Library deinitialization.
172 *
173 * This function clears all data associated with the PSA layer,
174 * including the whole key store.
175 *
176 * This is an Mbed TLS extension.
177 */
178void mbedtls_psa_crypto_free( void );
179
Gilles Peskine4bac9a42019-05-23 20:32:30 +0200180/** \brief Statistics about
181 * resource consumption related to the PSA keystore.
182 *
183 * \note The content of this structure is not part of the stable API and ABI
184 * of Mbed Crypto and may change arbitrarily from version to version.
185 */
186typedef struct mbedtls_psa_stats_s
187{
188 /** Number of slots containing key material for a volatile key. */
189 size_t volatile_slots;
190 /** Number of slots containing key material for a key which is in
191 * internal persistent storage. */
192 size_t persistent_slots;
193 /** Number of slots containing a reference to a key in a
194 * secure element. */
195 size_t external_slots;
196 /** Number of slots which are occupied, but do not contain
197 * key material yet. */
198 size_t half_filled_slots;
199 /** Number of slots that contain cache data. */
200 size_t cache_slots;
201 /** Number of slots that are not used for anything. */
202 size_t empty_slots;
203 /** Largest key id value among open keys in internal persistent storage. */
204 psa_key_id_t max_open_internal_key_id;
205 /** Largest key id value among open keys in secure elements. */
206 psa_key_id_t max_open_external_key_id;
207} mbedtls_psa_stats_t;
208
209/** \brief Get statistics about
210 * resource consumption related to the PSA keystore.
211 *
212 * \note When Mbed Crypto is built as part of a service, with isolation
213 * between the application and the keystore, the service may or
214 * may not expose this function.
215 */
216void mbedtls_psa_get_stats( mbedtls_psa_stats_t *stats );
Netanel Gonen2bcd3122018-11-19 11:53:02 +0200217
Netanel Gonen2bcd3122018-11-19 11:53:02 +0200218/**
Gilles Peskineee2ffd32018-11-16 11:02:49 +0100219 * \brief Inject an initial entropy seed for the random generator into
220 * secure storage.
Gilles Peskine0338ded2018-11-15 18:19:27 +0100221 *
222 * This function injects data to be used as a seed for the random generator
223 * used by the PSA Crypto implementation. On devices that lack a trusted
224 * entropy source (preferably a hardware random number generator),
225 * the Mbed PSA Crypto implementation uses this value to seed its
226 * random generator.
227 *
228 * On devices without a trusted entropy source, this function must be
229 * called exactly once in the lifetime of the device. On devices with
230 * a trusted entropy source, calling this function is optional.
231 * In all cases, this function may only be called before calling any
232 * other function in the PSA Crypto API, including psa_crypto_init().
233 *
234 * When this function returns successfully, it populates a file in
235 * persistent storage. Once the file has been created, this function
236 * can no longer succeed.
Gilles Peskineee2ffd32018-11-16 11:02:49 +0100237 *
238 * If any error occurs, this function does not change the system state.
239 * You can call this function again after correcting the reason for the
240 * error if possible.
Netanel Gonen2bcd3122018-11-19 11:53:02 +0200241 *
242 * \warning This function **can** fail! Callers MUST check the return status.
243 *
Gilles Peskine0338ded2018-11-15 18:19:27 +0100244 * \warning If you use this function, you should use it as part of a
245 * factory provisioning process. The value of the injected seed
246 * is critical to the security of the device. It must be
247 * *secret*, *unpredictable* and (statistically) *unique per device*.
248 * You should be generate it randomly using a cryptographically
249 * secure random generator seeded from trusted entropy sources.
250 * You should transmit it securely to the device and ensure
251 * that its value is not leaked or stored anywhere beyond the
252 * needs of transmitting it from the point of generation to
253 * the call of this function, and erase all copies of the value
254 * once this function returns.
Netanel Gonen2bcd3122018-11-19 11:53:02 +0200255 *
Gilles Peskine0338ded2018-11-15 18:19:27 +0100256 * This is an Mbed TLS extension.
257 *
Netanel Gonen1d7195f2018-11-22 16:24:48 +0200258 * \note This function is only available on the following platforms:
Gilles Peskinee3dbdd82019-02-25 11:04:06 +0100259 * * If the compile-time option MBEDTLS_PSA_INJECT_ENTROPY is enabled.
260 * Note that you must provide compatible implementations of
261 * mbedtls_nv_seed_read and mbedtls_nv_seed_write.
Gilles Peskine0cfaed12018-11-22 17:11:45 +0200262 * * In a client-server integration of PSA Cryptography, on the client side,
Netanel Gonen1d7195f2018-11-22 16:24:48 +0200263 * if the server supports this feature.
Netanel Gonen596e65e2018-11-22 18:41:43 +0200264 * \param[in] seed Buffer containing the seed value to inject.
Gilles Peskine0cfaed12018-11-22 17:11:45 +0200265 * \param[in] seed_size Size of the \p seed buffer.
Netanel Gonen596e65e2018-11-22 18:41:43 +0200266 * The size of the seed in bytes must be greater
267 * or equal to both #MBEDTLS_ENTROPY_MIN_PLATFORM
268 * and #MBEDTLS_ENTROPY_BLOCK_SIZE.
269 * It must be less or equal to
270 * #MBEDTLS_ENTROPY_MAX_SEED_SIZE.
Netanel Gonen2bcd3122018-11-19 11:53:02 +0200271 *
272 * \retval #PSA_SUCCESS
Gilles Peskine0338ded2018-11-15 18:19:27 +0100273 * The seed value was injected successfully. The random generator
274 * of the PSA Crypto implementation is now ready for use.
275 * You may now call psa_crypto_init() and use the PSA Crypto
276 * implementation.
Netanel Gonen2bcd3122018-11-19 11:53:02 +0200277 * \retval #PSA_ERROR_INVALID_ARGUMENT
Gilles Peskineee2ffd32018-11-16 11:02:49 +0100278 * \p seed_size is out of range.
Netanel Gonen2bcd3122018-11-19 11:53:02 +0200279 * \retval #PSA_ERROR_STORAGE_FAILURE
Gilles Peskine0338ded2018-11-15 18:19:27 +0100280 * There was a failure reading or writing from storage.
Netanel Gonen2bcd3122018-11-19 11:53:02 +0200281 * \retval #PSA_ERROR_NOT_PERMITTED
Gilles Peskine0338ded2018-11-15 18:19:27 +0100282 * The library has already been initialized. It is no longer
283 * possible to call this function.
Netanel Gonen2bcd3122018-11-19 11:53:02 +0200284 */
Gilles Peskine7228da22019-07-15 11:06:15 +0200285psa_status_t mbedtls_psa_inject_entropy(uint8_t *seed,
Netanel Gonen2bcd3122018-11-19 11:53:02 +0200286 size_t seed_size);
287
Janos Follath71a4c912019-06-11 09:14:47 +0100288#if defined(PSA_PRE_1_0_KEY_DERIVATION)
Gilles Peskine5dcd3ce2019-01-18 16:41:31 +0100289/** Set up a key derivation operation.
290 *
291 * FIMXE This function is no longer part of the official API. Its prototype
292 * is only kept around for the sake of tests that haven't been updated yet.
293 *
Gilles Peskine3be6b7f2019-03-05 19:32:26 +0100294 * A key derivation algorithm takes three inputs: a secret input \p handle and
Gilles Peskine5dcd3ce2019-01-18 16:41:31 +0100295 * two non-secret inputs \p label and p salt.
296 * The result of this function is a byte generator which can
297 * be used to produce keys and other cryptographic material.
298 *
299 * The role of \p label and \p salt is as follows:
300 * - For HKDF (#PSA_ALG_HKDF), \p salt is the salt used in the "extract" step
301 * and \p label is the info string used in the "expand" step.
302 *
Gilles Peskinecf7292e2019-05-16 17:53:40 +0200303 * \param[in,out] operation The key derivation object to set up. It must
304 * have been initialized as per the documentation
305 * for #psa_key_derivation_operation_t and not
306 * yet be in use.
Gilles Peskine5dcd3ce2019-01-18 16:41:31 +0100307 * \param handle Handle to the secret key.
308 * \param alg The key derivation algorithm to compute
309 * (\c PSA_ALG_XXX value such that
310 * #PSA_ALG_IS_KEY_DERIVATION(\p alg) is true).
311 * \param[in] salt Salt to use.
312 * \param salt_length Size of the \p salt buffer in bytes.
313 * \param[in] label Label to use.
314 * \param label_length Size of the \p label buffer in bytes.
315 * \param capacity The maximum number of bytes that the
Gilles Peskine35675b62019-05-16 17:26:11 +0200316 * operation will be able to provide.
Gilles Peskine5dcd3ce2019-01-18 16:41:31 +0100317 *
318 * \retval #PSA_SUCCESS
319 * Success.
320 * \retval #PSA_ERROR_INVALID_HANDLE
321 * \retval #PSA_ERROR_EMPTY_SLOT
322 * \retval #PSA_ERROR_NOT_PERMITTED
323 * \retval #PSA_ERROR_INVALID_ARGUMENT
324 * \c key is not compatible with \c alg,
325 * or \p capacity is too large for the specified algorithm and key.
326 * \retval #PSA_ERROR_NOT_SUPPORTED
327 * \c alg is not supported or is not a key derivation algorithm.
328 * \retval #PSA_ERROR_INSUFFICIENT_MEMORY
329 * \retval #PSA_ERROR_COMMUNICATION_FAILURE
330 * \retval #PSA_ERROR_HARDWARE_FAILURE
Gilles Peskine4b3eb692019-05-16 21:35:18 +0200331 * \retval #PSA_ERROR_CORRUPTION_DETECTED
Gilles Peskine5dcd3ce2019-01-18 16:41:31 +0100332 * \retval #PSA_ERROR_BAD_STATE
333 * The library has not been previously initialized by psa_crypto_init().
334 * It is implementation-dependent whether a failure to initialize
335 * results in this error code.
336 */
Gilles Peskine35675b62019-05-16 17:26:11 +0200337psa_status_t psa_key_derivation(psa_key_derivation_operation_t *operation,
Gilles Peskine5dcd3ce2019-01-18 16:41:31 +0100338 psa_key_handle_t handle,
339 psa_algorithm_t alg,
340 const uint8_t *salt,
341 size_t salt_length,
342 const uint8_t *label,
343 size_t label_length,
344 size_t capacity);
Janos Follath71a4c912019-06-11 09:14:47 +0100345#endif /* PSA_PRE_1_0_KEY_DERIVATION */
Gilles Peskine5dcd3ce2019-01-18 16:41:31 +0100346
Gilles Peskinee38ab1a2019-05-16 13:51:50 +0200347/** \addtogroup crypto_types
348 * @{
349 */
350
Gilles Peskinea1302192019-05-16 13:58:24 +0200351/** DSA public key.
352 *
353 * The import and export format is the
354 * representation of the public key `y = g^x mod p` as a big-endian byte
355 * string. The length of the byte string is the length of the base prime `p`
356 * in bytes.
357 */
Gilles Peskinee38ab1a2019-05-16 13:51:50 +0200358#define PSA_KEY_TYPE_DSA_PUBLIC_KEY ((psa_key_type_t)0x60020000)
Gilles Peskinea1302192019-05-16 13:58:24 +0200359
360/** DSA key pair (private and public key).
361 *
362 * The import and export format is the
363 * representation of the private key `x` as a big-endian byte string. The
364 * length of the byte string is the private key size in bytes (leading zeroes
365 * are not stripped).
366 *
367 * Determinstic DSA key derivation with psa_generate_derived_key follows
368 * FIPS 186-4 §B.1.2: interpret the byte string as integer
369 * in big-endian order. Discard it if it is not in the range
370 * [0, *N* - 2] where *N* is the boundary of the private key domain
371 * (the prime *p* for Diffie-Hellman, the subprime *q* for DSA,
372 * or the order of the curve's base point for ECC).
373 * Add 1 to the resulting integer and use this as the private key *x*.
374 *
375 */
Gilles Peskinec93b80c2019-05-16 19:39:54 +0200376#define PSA_KEY_TYPE_DSA_KEY_PAIR ((psa_key_type_t)0x70020000)
Gilles Peskinea1302192019-05-16 13:58:24 +0200377
Gilles Peskinee38ab1a2019-05-16 13:51:50 +0200378/** Whether a key type is an DSA key (pair or public-only). */
379#define PSA_KEY_TYPE_IS_DSA(type) \
Gilles Peskinec93b80c2019-05-16 19:39:54 +0200380 (PSA_KEY_TYPE_PUBLIC_KEY_OF_KEY_PAIR(type) == PSA_KEY_TYPE_DSA_PUBLIC_KEY)
Gilles Peskinee38ab1a2019-05-16 13:51:50 +0200381
382#define PSA_ALG_DSA_BASE ((psa_algorithm_t)0x10040000)
383/** DSA signature with hashing.
384 *
385 * This is the signature scheme defined by FIPS 186-4,
386 * with a random per-message secret number (*k*).
387 *
388 * \param hash_alg A hash algorithm (\c PSA_ALG_XXX value such that
389 * #PSA_ALG_IS_HASH(\p hash_alg) is true).
390 * This includes #PSA_ALG_ANY_HASH
391 * when specifying the algorithm in a usage policy.
392 *
393 * \return The corresponding DSA signature algorithm.
394 * \return Unspecified if \p hash_alg is not a supported
395 * hash algorithm.
396 */
397#define PSA_ALG_DSA(hash_alg) \
398 (PSA_ALG_DSA_BASE | ((hash_alg) & PSA_ALG_HASH_MASK))
399#define PSA_ALG_DETERMINISTIC_DSA_BASE ((psa_algorithm_t)0x10050000)
400#define PSA_ALG_DSA_DETERMINISTIC_FLAG ((psa_algorithm_t)0x00010000)
401/** Deterministic DSA signature with hashing.
402 *
403 * This is the deterministic variant defined by RFC 6979 of
404 * the signature scheme defined by FIPS 186-4.
405 *
406 * \param hash_alg A hash algorithm (\c PSA_ALG_XXX value such that
407 * #PSA_ALG_IS_HASH(\p hash_alg) is true).
408 * This includes #PSA_ALG_ANY_HASH
409 * when specifying the algorithm in a usage policy.
410 *
411 * \return The corresponding DSA signature algorithm.
412 * \return Unspecified if \p hash_alg is not a supported
413 * hash algorithm.
414 */
415#define PSA_ALG_DETERMINISTIC_DSA(hash_alg) \
416 (PSA_ALG_DETERMINISTIC_DSA_BASE | ((hash_alg) & PSA_ALG_HASH_MASK))
417#define PSA_ALG_IS_DSA(alg) \
418 (((alg) & ~PSA_ALG_HASH_MASK & ~PSA_ALG_DSA_DETERMINISTIC_FLAG) == \
419 PSA_ALG_DSA_BASE)
420#define PSA_ALG_DSA_IS_DETERMINISTIC(alg) \
421 (((alg) & PSA_ALG_DSA_DETERMINISTIC_FLAG) != 0)
422#define PSA_ALG_IS_DETERMINISTIC_DSA(alg) \
423 (PSA_ALG_IS_DSA(alg) && PSA_ALG_DSA_IS_DETERMINISTIC(alg))
424#define PSA_ALG_IS_RANDOMIZED_DSA(alg) \
425 (PSA_ALG_IS_DSA(alg) && !PSA_ALG_DSA_IS_DETERMINISTIC(alg))
426
427
428/* We need to expand the sample definition of this macro from
429 * the API definition. */
430#undef PSA_ALG_IS_HASH_AND_SIGN
431#define PSA_ALG_IS_HASH_AND_SIGN(alg) \
432 (PSA_ALG_IS_RSA_PSS(alg) || PSA_ALG_IS_RSA_PKCS1V15_SIGN(alg) || \
433 PSA_ALG_IS_DSA(alg) || PSA_ALG_IS_ECDSA(alg))
434
435/**@}*/
436
Gilles Peskine24f10f82019-05-16 12:18:32 +0200437/** \addtogroup attributes
438 * @{
439 */
440
Gilles Peskinedcaefae2019-05-16 12:55:35 +0200441/** Custom Diffie-Hellman group.
442 *
443 * For keys of type #PSA_KEY_TYPE_DH_PUBLIC_KEY(#PSA_DH_GROUP_CUSTOM) or
Gilles Peskinec93b80c2019-05-16 19:39:54 +0200444 * #PSA_KEY_TYPE_DH_KEY_PAIR(#PSA_DH_GROUP_CUSTOM), the group data comes
Gilles Peskinedcaefae2019-05-16 12:55:35 +0200445 * from domain parameters set by psa_set_key_domain_parameters().
446 */
447/* This value is reserved for private use in the TLS named group registry. */
448#define PSA_DH_GROUP_CUSTOM ((psa_dh_group_t) 0x01fc)
449
450
Gilles Peskine24f10f82019-05-16 12:18:32 +0200451/**
452 * \brief Set domain parameters for a key.
453 *
454 * Some key types require additional domain parameters in addition to
455 * the key type identifier and the key size. Use this function instead
456 * of psa_set_key_type() when you need to specify domain parameters.
457 *
458 * The format for the required domain parameters varies based on the key type.
459 *
Gilles Peskinec93b80c2019-05-16 19:39:54 +0200460 * - For RSA keys (#PSA_KEY_TYPE_RSA_PUBLIC_KEY or #PSA_KEY_TYPE_RSA_KEY_PAIR),
Gilles Peskine24f10f82019-05-16 12:18:32 +0200461 * the domain parameter data consists of the public exponent,
462 * represented as a big-endian integer with no leading zeros.
463 * This information is used when generating an RSA key pair.
464 * When importing a key, the public exponent is read from the imported
465 * key data and the exponent recorded in the attribute structure is ignored.
466 * As an exception, the public exponent 65537 is represented by an empty
467 * byte string.
Gilles Peskinec93b80c2019-05-16 19:39:54 +0200468 * - For DSA keys (#PSA_KEY_TYPE_DSA_PUBLIC_KEY or #PSA_KEY_TYPE_DSA_KEY_PAIR),
Gilles Peskine24f10f82019-05-16 12:18:32 +0200469 * the `Dss-Parms` format as defined by RFC 3279 §2.3.2.
470 * ```
471 * Dss-Parms ::= SEQUENCE {
472 * p INTEGER,
473 * q INTEGER,
474 * g INTEGER
475 * }
476 * ```
Gilles Peskinedcaefae2019-05-16 12:55:35 +0200477 * - For Diffie-Hellman key exchange keys
478 * (#PSA_KEY_TYPE_DH_PUBLIC_KEY(#PSA_DH_GROUP_CUSTOM) or
Gilles Peskinec93b80c2019-05-16 19:39:54 +0200479 * #PSA_KEY_TYPE_DH_KEY_PAIR(#PSA_DH_GROUP_CUSTOM)), the
Gilles Peskine24f10f82019-05-16 12:18:32 +0200480 * `DomainParameters` format as defined by RFC 3279 §2.3.3.
481 * ```
482 * DomainParameters ::= SEQUENCE {
483 * p INTEGER, -- odd prime, p=jq +1
484 * g INTEGER, -- generator, g
485 * q INTEGER, -- factor of p-1
486 * j INTEGER OPTIONAL, -- subgroup factor
487 * validationParms ValidationParms OPTIONAL
488 * }
489 * ValidationParms ::= SEQUENCE {
490 * seed BIT STRING,
491 * pgenCounter INTEGER
492 * }
493 * ```
494 *
495 * \note This function may allocate memory or other resources.
496 * Once you have called this function on an attribute structure,
497 * you must call psa_reset_key_attributes() to free these resources.
498 *
499 * \note This is an experimental extension to the interface. It may change
500 * in future versions of the library.
501 *
502 * \param[in,out] attributes Attribute structure where the specified domain
503 * parameters will be stored.
504 * If this function fails, the content of
505 * \p attributes is not modified.
506 * \param type Key type (a \c PSA_KEY_TYPE_XXX value).
507 * \param[in] data Buffer containing the key domain parameters.
508 * The content of this buffer is interpreted
509 * according to \p type as described above.
510 * \param data_length Size of the \p data buffer in bytes.
511 *
512 * \retval #PSA_SUCCESS
513 * \retval #PSA_ERROR_INVALID_ARGUMENT
514 * \retval #PSA_ERROR_NOT_SUPPORTED
515 * \retval #PSA_ERROR_INSUFFICIENT_MEMORY
516 */
517psa_status_t psa_set_key_domain_parameters(psa_key_attributes_t *attributes,
518 psa_key_type_t type,
519 const uint8_t *data,
520 size_t data_length);
521
522/**
523 * \brief Get domain parameters for a key.
524 *
525 * Get the domain parameters for a key with this function, if any. The format
526 * of the domain parameters written to \p data is specified in the
527 * documentation for psa_set_key_domain_parameters().
528 *
529 * \note This is an experimental extension to the interface. It may change
530 * in future versions of the library.
531 *
532 * \param[in] attributes The key attribute structure to query.
533 * \param[out] data On success, the key domain parameters.
534 * \param data_size Size of the \p data buffer in bytes.
535 * The buffer is guaranteed to be large
536 * enough if its size in bytes is at least
537 * the value given by
538 * PSA_KEY_DOMAIN_PARAMETERS_SIZE().
539 * \param[out] data_length On success, the number of bytes
540 * that make up the key domain parameters data.
541 *
542 * \retval #PSA_SUCCESS
543 * \retval #PSA_ERROR_BUFFER_TOO_SMALL
544 */
545psa_status_t psa_get_key_domain_parameters(
546 const psa_key_attributes_t *attributes,
547 uint8_t *data,
548 size_t data_size,
549 size_t *data_length);
550
551/** Safe output buffer size for psa_get_key_domain_parameters().
552 *
553 * This macro returns a compile-time constant if its arguments are
554 * compile-time constants.
555 *
556 * \warning This function may call its arguments multiple times or
557 * zero times, so you should not pass arguments that contain
558 * side effects.
559 *
560 * \note This is an experimental extension to the interface. It may change
561 * in future versions of the library.
562 *
563 * \param key_type A supported key type.
564 * \param key_bits The size of the key in bits.
565 *
566 * \return If the parameters are valid and supported, return
567 * a buffer size in bytes that guarantees that
568 * psa_get_key_domain_parameters() will not fail with
569 * #PSA_ERROR_BUFFER_TOO_SMALL.
570 * If the parameters are a valid combination that is not supported
Gilles Peskine27a983d2019-05-16 17:24:53 +0200571 * by the implementation, this macro shall return either a
Gilles Peskine24f10f82019-05-16 12:18:32 +0200572 * sensible size or 0.
573 * If the parameters are not valid, the
574 * return value is unspecified.
575 */
576#define PSA_KEY_DOMAIN_PARAMETERS_SIZE(key_type, key_bits) \
577 (PSA_KEY_TYPE_IS_RSA(key_type) ? sizeof(int) : \
578 PSA_KEY_TYPE_IS_DH(key_type) ? PSA_DH_KEY_DOMAIN_PARAMETERS_SIZE(key_bits) : \
579 PSA_KEY_TYPE_IS_DSA(key_type) ? PSA_DSA_KEY_DOMAIN_PARAMETERS_SIZE(key_bits) : \
580 0)
581#define PSA_DH_KEY_DOMAIN_PARAMETERS_SIZE(key_bits) \
582 (4 + (PSA_BITS_TO_BYTES(key_bits) + 5) * 3 /*without optional parts*/)
583#define PSA_DSA_KEY_DOMAIN_PARAMETERS_SIZE(key_bits) \
584 (4 + (PSA_BITS_TO_BYTES(key_bits) + 5) * 2 /*p, g*/ + 34 /*q*/)
585
586/**@}*/
587
Gilles Peskinee59236f2018-01-27 23:32:46 +0100588#ifdef __cplusplus
589}
590#endif
591
592#endif /* PSA_CRYPTO_EXTRA_H */