1 /**
2 * \file cipher.h
3 *
4 * \brief This file contains an abstraction interface for use with the cipher
5 * primitives provided by the library. It provides a common interface to all of
6 * the available cipher operations.
7 *
8 * \author Adriaan de Jong <dejong@fox-it.com>
9 */
10 /*
11 * Copyright The Mbed TLS Contributors
12 * SPDX-License-Identifier: Apache-2.0
13 *
14 * Licensed under the Apache License, Version 2.0 (the "License"); you may
15 * not use this file except in compliance with the License.
16 * You may obtain a copy of the License at
17 *
18 * http://www.apache.org/licenses/LICENSE-2.0
19 *
20 * Unless required by applicable law or agreed to in writing, software
21 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
22 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
23 * See the License for the specific language governing permissions and
24 * limitations under the License.
25 */
26
27 #ifndef MBEDTLS_CIPHER_H
28 #define MBEDTLS_CIPHER_H
29 #include "mbedtls/private_access.h"
30
31 #include "mbedtls/build_info.h"
32
33 #include <stddef.h>
34 #include "mbedtls/platform_util.h"
35
36 #if defined(MBEDTLS_GCM_C) || defined(MBEDTLS_CCM_C) || defined(MBEDTLS_CHACHAPOLY_C)
37 #define MBEDTLS_CIPHER_MODE_AEAD
38 #endif
39
40 #if defined(MBEDTLS_CIPHER_MODE_CBC)
41 #define MBEDTLS_CIPHER_MODE_WITH_PADDING
42 #endif
43
44 #if defined(MBEDTLS_CIPHER_NULL_CIPHER) || \
45 defined(MBEDTLS_CHACHA20_C)
46 #define MBEDTLS_CIPHER_MODE_STREAM
47 #endif
48
49 #if ( defined(__ARMCC_VERSION) || defined(_MSC_VER) ) && \
50 !defined(inline) && !defined(__cplusplus)
51 #define inline __inline
52 #endif
53
54 /** The selected feature is not available. */
55 #define MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE -0x6080
56 /** Bad input parameters. */
57 #define MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA -0x6100
58 /** Failed to allocate memory. */
59 #define MBEDTLS_ERR_CIPHER_ALLOC_FAILED -0x6180
60 /** Input data contains invalid padding and is rejected. */
61 #define MBEDTLS_ERR_CIPHER_INVALID_PADDING -0x6200
62 /** Decryption of block requires a full block. */
63 #define MBEDTLS_ERR_CIPHER_FULL_BLOCK_EXPECTED -0x6280
64 /** Authentication failed (for AEAD modes). */
65 #define MBEDTLS_ERR_CIPHER_AUTH_FAILED -0x6300
66 /** The context is invalid. For example, because it was freed. */
67 #define MBEDTLS_ERR_CIPHER_INVALID_CONTEXT -0x6380
68
69 #define MBEDTLS_CIPHER_VARIABLE_IV_LEN 0x01 /**< Cipher accepts IVs of variable length. */
70 #define MBEDTLS_CIPHER_VARIABLE_KEY_LEN 0x02 /**< Cipher accepts keys of variable length. */
71
72 #ifdef __cplusplus
73 extern "C" {
74 #endif
75
76 /**
77 * \brief Supported cipher types.
78 *
79 * \warning DES is considered weak cipher and its use
80 * constitutes a security risk. Arm recommends considering stronger
81 * ciphers instead.
82 */
83 typedef enum {
84 MBEDTLS_CIPHER_ID_NONE = 0, /**< Placeholder to mark the end of cipher ID lists. */
85 MBEDTLS_CIPHER_ID_NULL, /**< The identity cipher, treated as a stream cipher. */
86 MBEDTLS_CIPHER_ID_AES, /**< The AES cipher. */
87 MBEDTLS_CIPHER_ID_DES, /**< The DES cipher. */
88 MBEDTLS_CIPHER_ID_3DES, /**< The Triple DES cipher. */
89 MBEDTLS_CIPHER_ID_CAMELLIA, /**< The Camellia cipher. */
90 MBEDTLS_CIPHER_ID_ARIA, /**< The Aria cipher. */
91 MBEDTLS_CIPHER_ID_CHACHA20, /**< The ChaCha20 cipher. */
92 } mbedtls_cipher_id_t;
93
94 /**
95 * \brief Supported {cipher type, cipher mode} pairs.
96 *
97 * \warning DES is considered weak cipher and its use
98 * constitutes a security risk. Arm recommends considering stronger
99 * ciphers instead.
100 */
101 typedef enum {
102 MBEDTLS_CIPHER_NONE = 0, /**< Placeholder to mark the end of cipher-pair lists. */
103 MBEDTLS_CIPHER_NULL, /**< The identity stream cipher. */
104 MBEDTLS_CIPHER_AES_128_ECB, /**< AES cipher with 128-bit ECB mode. */
105 MBEDTLS_CIPHER_AES_192_ECB, /**< AES cipher with 192-bit ECB mode. */
106 MBEDTLS_CIPHER_AES_256_ECB, /**< AES cipher with 256-bit ECB mode. */
107 MBEDTLS_CIPHER_AES_128_CBC, /**< AES cipher with 128-bit CBC mode. */
108 MBEDTLS_CIPHER_AES_192_CBC, /**< AES cipher with 192-bit CBC mode. */
109 MBEDTLS_CIPHER_AES_256_CBC, /**< AES cipher with 256-bit CBC mode. */
110 MBEDTLS_CIPHER_AES_128_CFB128, /**< AES cipher with 128-bit CFB128 mode. */
111 MBEDTLS_CIPHER_AES_192_CFB128, /**< AES cipher with 192-bit CFB128 mode. */
112 MBEDTLS_CIPHER_AES_256_CFB128, /**< AES cipher with 256-bit CFB128 mode. */
113 MBEDTLS_CIPHER_AES_128_CTR, /**< AES cipher with 128-bit CTR mode. */
114 MBEDTLS_CIPHER_AES_192_CTR, /**< AES cipher with 192-bit CTR mode. */
115 MBEDTLS_CIPHER_AES_256_CTR, /**< AES cipher with 256-bit CTR mode. */
116 MBEDTLS_CIPHER_AES_128_GCM, /**< AES cipher with 128-bit GCM mode. */
117 MBEDTLS_CIPHER_AES_192_GCM, /**< AES cipher with 192-bit GCM mode. */
118 MBEDTLS_CIPHER_AES_256_GCM, /**< AES cipher with 256-bit GCM mode. */
119 MBEDTLS_CIPHER_CAMELLIA_128_ECB, /**< Camellia cipher with 128-bit ECB mode. */
120 MBEDTLS_CIPHER_CAMELLIA_192_ECB, /**< Camellia cipher with 192-bit ECB mode. */
121 MBEDTLS_CIPHER_CAMELLIA_256_ECB, /**< Camellia cipher with 256-bit ECB mode. */
122 MBEDTLS_CIPHER_CAMELLIA_128_CBC, /**< Camellia cipher with 128-bit CBC mode. */
123 MBEDTLS_CIPHER_CAMELLIA_192_CBC, /**< Camellia cipher with 192-bit CBC mode. */
124 MBEDTLS_CIPHER_CAMELLIA_256_CBC, /**< Camellia cipher with 256-bit CBC mode. */
125 MBEDTLS_CIPHER_CAMELLIA_128_CFB128, /**< Camellia cipher with 128-bit CFB128 mode. */
126 MBEDTLS_CIPHER_CAMELLIA_192_CFB128, /**< Camellia cipher with 192-bit CFB128 mode. */
127 MBEDTLS_CIPHER_CAMELLIA_256_CFB128, /**< Camellia cipher with 256-bit CFB128 mode. */
128 MBEDTLS_CIPHER_CAMELLIA_128_CTR, /**< Camellia cipher with 128-bit CTR mode. */
129 MBEDTLS_CIPHER_CAMELLIA_192_CTR, /**< Camellia cipher with 192-bit CTR mode. */
130 MBEDTLS_CIPHER_CAMELLIA_256_CTR, /**< Camellia cipher with 256-bit CTR mode. */
131 MBEDTLS_CIPHER_CAMELLIA_128_GCM, /**< Camellia cipher with 128-bit GCM mode. */
132 MBEDTLS_CIPHER_CAMELLIA_192_GCM, /**< Camellia cipher with 192-bit GCM mode. */
133 MBEDTLS_CIPHER_CAMELLIA_256_GCM, /**< Camellia cipher with 256-bit GCM mode. */
134 MBEDTLS_CIPHER_DES_ECB, /**< DES cipher with ECB mode. */
135 MBEDTLS_CIPHER_DES_CBC, /**< DES cipher with CBC mode. */
136 MBEDTLS_CIPHER_DES_EDE_ECB, /**< DES cipher with EDE ECB mode. */
137 MBEDTLS_CIPHER_DES_EDE_CBC, /**< DES cipher with EDE CBC mode. */
138 MBEDTLS_CIPHER_DES_EDE3_ECB, /**< DES cipher with EDE3 ECB mode. */
139 MBEDTLS_CIPHER_DES_EDE3_CBC, /**< DES cipher with EDE3 CBC mode. */
140 MBEDTLS_CIPHER_AES_128_CCM, /**< AES cipher with 128-bit CCM mode. */
141 MBEDTLS_CIPHER_AES_192_CCM, /**< AES cipher with 192-bit CCM mode. */
142 MBEDTLS_CIPHER_AES_256_CCM, /**< AES cipher with 256-bit CCM mode. */
143 MBEDTLS_CIPHER_AES_128_CCM_STAR_NO_TAG, /**< AES cipher with 128-bit CCM_STAR_NO_TAG mode. */
144 MBEDTLS_CIPHER_AES_192_CCM_STAR_NO_TAG, /**< AES cipher with 192-bit CCM_STAR_NO_TAG mode. */
145 MBEDTLS_CIPHER_AES_256_CCM_STAR_NO_TAG, /**< AES cipher with 256-bit CCM_STAR_NO_TAG mode. */
146 MBEDTLS_CIPHER_CAMELLIA_128_CCM, /**< Camellia cipher with 128-bit CCM mode. */
147 MBEDTLS_CIPHER_CAMELLIA_192_CCM, /**< Camellia cipher with 192-bit CCM mode. */
148 MBEDTLS_CIPHER_CAMELLIA_256_CCM, /**< Camellia cipher with 256-bit CCM mode. */
149 MBEDTLS_CIPHER_CAMELLIA_128_CCM_STAR_NO_TAG, /**< Camellia cipher with 128-bit CCM_STAR_NO_TAG mode. */
150 MBEDTLS_CIPHER_CAMELLIA_192_CCM_STAR_NO_TAG, /**< Camellia cipher with 192-bit CCM_STAR_NO_TAG mode. */
151 MBEDTLS_CIPHER_CAMELLIA_256_CCM_STAR_NO_TAG, /**< Camellia cipher with 256-bit CCM_STAR_NO_TAG mode. */
152 MBEDTLS_CIPHER_ARIA_128_ECB, /**< Aria cipher with 128-bit key and ECB mode. */
153 MBEDTLS_CIPHER_ARIA_192_ECB, /**< Aria cipher with 192-bit key and ECB mode. */
154 MBEDTLS_CIPHER_ARIA_256_ECB, /**< Aria cipher with 256-bit key and ECB mode. */
155 MBEDTLS_CIPHER_ARIA_128_CBC, /**< Aria cipher with 128-bit key and CBC mode. */
156 MBEDTLS_CIPHER_ARIA_192_CBC, /**< Aria cipher with 192-bit key and CBC mode. */
157 MBEDTLS_CIPHER_ARIA_256_CBC, /**< Aria cipher with 256-bit key and CBC mode. */
158 MBEDTLS_CIPHER_ARIA_128_CFB128, /**< Aria cipher with 128-bit key and CFB-128 mode. */
159 MBEDTLS_CIPHER_ARIA_192_CFB128, /**< Aria cipher with 192-bit key and CFB-128 mode. */
160 MBEDTLS_CIPHER_ARIA_256_CFB128, /**< Aria cipher with 256-bit key and CFB-128 mode. */
161 MBEDTLS_CIPHER_ARIA_128_CTR, /**< Aria cipher with 128-bit key and CTR mode. */
162 MBEDTLS_CIPHER_ARIA_192_CTR, /**< Aria cipher with 192-bit key and CTR mode. */
163 MBEDTLS_CIPHER_ARIA_256_CTR, /**< Aria cipher with 256-bit key and CTR mode. */
164 MBEDTLS_CIPHER_ARIA_128_GCM, /**< Aria cipher with 128-bit key and GCM mode. */
165 MBEDTLS_CIPHER_ARIA_192_GCM, /**< Aria cipher with 192-bit key and GCM mode. */
166 MBEDTLS_CIPHER_ARIA_256_GCM, /**< Aria cipher with 256-bit key and GCM mode. */
167 MBEDTLS_CIPHER_ARIA_128_CCM, /**< Aria cipher with 128-bit key and CCM mode. */
168 MBEDTLS_CIPHER_ARIA_192_CCM, /**< Aria cipher with 192-bit key and CCM mode. */
169 MBEDTLS_CIPHER_ARIA_256_CCM, /**< Aria cipher with 256-bit key and CCM mode. */
170 MBEDTLS_CIPHER_ARIA_128_CCM_STAR_NO_TAG, /**< Aria cipher with 128-bit key and CCM_STAR_NO_TAG mode. */
171 MBEDTLS_CIPHER_ARIA_192_CCM_STAR_NO_TAG, /**< Aria cipher with 192-bit key and CCM_STAR_NO_TAG mode. */
172 MBEDTLS_CIPHER_ARIA_256_CCM_STAR_NO_TAG, /**< Aria cipher with 256-bit key and CCM_STAR_NO_TAG mode. */
173 MBEDTLS_CIPHER_AES_128_OFB, /**< AES 128-bit cipher in OFB mode. */
174 MBEDTLS_CIPHER_AES_192_OFB, /**< AES 192-bit cipher in OFB mode. */
175 MBEDTLS_CIPHER_AES_256_OFB, /**< AES 256-bit cipher in OFB mode. */
176 MBEDTLS_CIPHER_AES_128_XTS, /**< AES 128-bit cipher in XTS block mode. */
177 MBEDTLS_CIPHER_AES_256_XTS, /**< AES 256-bit cipher in XTS block mode. */
178 MBEDTLS_CIPHER_CHACHA20, /**< ChaCha20 stream cipher. */
179 MBEDTLS_CIPHER_CHACHA20_POLY1305, /**< ChaCha20-Poly1305 AEAD cipher. */
180 MBEDTLS_CIPHER_AES_128_KW, /**< AES cipher with 128-bit NIST KW mode. */
181 MBEDTLS_CIPHER_AES_192_KW, /**< AES cipher with 192-bit NIST KW mode. */
182 MBEDTLS_CIPHER_AES_256_KW, /**< AES cipher with 256-bit NIST KW mode. */
183 MBEDTLS_CIPHER_AES_128_KWP, /**< AES cipher with 128-bit NIST KWP mode. */
184 MBEDTLS_CIPHER_AES_192_KWP, /**< AES cipher with 192-bit NIST KWP mode. */
185 MBEDTLS_CIPHER_AES_256_KWP, /**< AES cipher with 256-bit NIST KWP mode. */
186 } mbedtls_cipher_type_t;
187
188 /** Supported cipher modes. */
189 typedef enum {
190 MBEDTLS_MODE_NONE = 0, /**< None. */
191 MBEDTLS_MODE_ECB, /**< The ECB cipher mode. */
192 MBEDTLS_MODE_CBC, /**< The CBC cipher mode. */
193 MBEDTLS_MODE_CFB, /**< The CFB cipher mode. */
194 MBEDTLS_MODE_OFB, /**< The OFB cipher mode. */
195 MBEDTLS_MODE_CTR, /**< The CTR cipher mode. */
196 MBEDTLS_MODE_GCM, /**< The GCM cipher mode. */
197 MBEDTLS_MODE_STREAM, /**< The stream cipher mode. */
198 MBEDTLS_MODE_CCM, /**< The CCM cipher mode. */
199 MBEDTLS_MODE_CCM_STAR_NO_TAG, /**< The CCM*-no-tag cipher mode. */
200 MBEDTLS_MODE_XTS, /**< The XTS cipher mode. */
201 MBEDTLS_MODE_CHACHAPOLY, /**< The ChaCha-Poly cipher mode. */
202 MBEDTLS_MODE_KW, /**< The SP800-38F KW mode */
203 MBEDTLS_MODE_KWP, /**< The SP800-38F KWP mode */
204 } mbedtls_cipher_mode_t;
205
206 /** Supported cipher padding types. */
207 typedef enum {
208 MBEDTLS_PADDING_PKCS7 = 0, /**< PKCS7 padding (default). */
209 MBEDTLS_PADDING_ONE_AND_ZEROS, /**< ISO/IEC 7816-4 padding. */
210 MBEDTLS_PADDING_ZEROS_AND_LEN, /**< ANSI X.923 padding. */
211 MBEDTLS_PADDING_ZEROS, /**< Zero padding (not reversible). */
212 MBEDTLS_PADDING_NONE, /**< Never pad (full blocks only). */
213 } mbedtls_cipher_padding_t;
214
215 /** Type of operation. */
216 typedef enum {
217 MBEDTLS_OPERATION_NONE = -1,
218 MBEDTLS_DECRYPT = 0,
219 MBEDTLS_ENCRYPT,
220 } mbedtls_operation_t;
221
222 enum {
223 /** Undefined key length. */
224 MBEDTLS_KEY_LENGTH_NONE = 0,
225 /** Key length, in bits (including parity), for DES keys. */
226 MBEDTLS_KEY_LENGTH_DES = 64,
227 /** Key length in bits, including parity, for DES in two-key EDE. */
228 MBEDTLS_KEY_LENGTH_DES_EDE = 128,
229 /** Key length in bits, including parity, for DES in three-key EDE. */
230 MBEDTLS_KEY_LENGTH_DES_EDE3 = 192,
231 };
232
233 /** Maximum length of any IV, in Bytes. */
234 /* This should ideally be derived automatically from list of ciphers.
235 * This should be kept in sync with MBEDTLS_SSL_MAX_IV_LENGTH defined
236 * in library/ssl_misc.h. */
237 #define MBEDTLS_MAX_IV_LENGTH 16
238
239 /** Maximum block size of any cipher, in Bytes. */
240 /* This should ideally be derived automatically from list of ciphers.
241 * This should be kept in sync with MBEDTLS_SSL_MAX_BLOCK_LENGTH defined
242 * in library/ssl_misc.h. */
243 #define MBEDTLS_MAX_BLOCK_LENGTH 16
244
245 /** Maximum key length, in Bytes. */
246 /* This should ideally be derived automatically from list of ciphers.
247 * For now, only check whether XTS is enabled which uses 64 Byte keys,
248 * and use 32 Bytes as an upper bound for the maximum key length otherwise.
249 * This should be kept in sync with MBEDTLS_SSL_MAX_BLOCK_LENGTH defined
250 * in library/ssl_misc.h, which however deliberately ignores the case of XTS
251 * since the latter isn't used in SSL/TLS. */
252 #if defined(MBEDTLS_CIPHER_MODE_XTS)
253 #define MBEDTLS_MAX_KEY_LENGTH 64
254 #else
255 #define MBEDTLS_MAX_KEY_LENGTH 32
256 #endif /* MBEDTLS_CIPHER_MODE_XTS */
257
258 /**
259 * Base cipher information (opaque struct).
260 */
261 typedef struct mbedtls_cipher_base_t mbedtls_cipher_base_t;
262
263 /**
264 * CMAC context (opaque struct).
265 */
266 typedef struct mbedtls_cmac_context_t mbedtls_cmac_context_t;
267
268 /**
269 * Cipher information. Allows calling cipher functions
270 * in a generic way.
271 *
272 * \note The library does not support custom cipher info structures,
273 * only built-in structures returned by the functions
274 * mbedtls_cipher_info_from_string(),
275 * mbedtls_cipher_info_from_type(),
276 * mbedtls_cipher_info_from_values(),
277 * mbedtls_cipher_info_from_psa().
278 */
279 typedef struct mbedtls_cipher_info_t
280 {
281 /** Full cipher identifier. For example,
282 * MBEDTLS_CIPHER_AES_256_CBC.
283 */
284 mbedtls_cipher_type_t MBEDTLS_PRIVATE(type);
285
286 /** The cipher mode. For example, MBEDTLS_MODE_CBC. */
287 mbedtls_cipher_mode_t MBEDTLS_PRIVATE(mode);
288
289 /** The cipher key length, in bits. This is the
290 * default length for variable sized ciphers.
291 * Includes parity bits for ciphers like DES.
292 */
293 unsigned int MBEDTLS_PRIVATE(key_bitlen);
294
295 /** Name of the cipher. */
296 const char * MBEDTLS_PRIVATE(name);
297
298 /** IV or nonce size, in Bytes.
299 * For ciphers that accept variable IV sizes,
300 * this is the recommended size.
301 */
302 unsigned int MBEDTLS_PRIVATE(iv_size);
303
304 /** Bitflag comprised of MBEDTLS_CIPHER_VARIABLE_IV_LEN and
305 * MBEDTLS_CIPHER_VARIABLE_KEY_LEN indicating whether the
306 * cipher supports variable IV or variable key sizes, respectively.
307 */
308 int MBEDTLS_PRIVATE(flags);
309
310 /** The block size, in Bytes. */
311 unsigned int MBEDTLS_PRIVATE(block_size);
312
313 /** Struct for base cipher information and functions. */
314 const mbedtls_cipher_base_t *MBEDTLS_PRIVATE(base);
315
316 } mbedtls_cipher_info_t;
317
318 /**
319 * Generic cipher context.
320 */
321 typedef struct mbedtls_cipher_context_t
322 {
323 /** Information about the associated cipher. */
324 const mbedtls_cipher_info_t *MBEDTLS_PRIVATE(cipher_info);
325
326 /** Key length to use. */
327 int MBEDTLS_PRIVATE(key_bitlen);
328
329 /** Operation that the key of the context has been
330 * initialized for.
331 */
332 mbedtls_operation_t MBEDTLS_PRIVATE(operation);
333
334 #if defined(MBEDTLS_CIPHER_MODE_WITH_PADDING)
335 /** Padding functions to use, if relevant for
336 * the specific cipher mode.
337 */
338 void (*MBEDTLS_PRIVATE(add_padding))( unsigned char *output, size_t olen, size_t data_len );
339 int (*MBEDTLS_PRIVATE(get_padding))( unsigned char *input, size_t ilen, size_t *data_len );
340 #endif
341
342 /** Buffer for input that has not been processed yet. */
343 unsigned char MBEDTLS_PRIVATE(unprocessed_data)[MBEDTLS_MAX_BLOCK_LENGTH];
344
345 /** Number of Bytes that have not been processed yet. */
346 size_t MBEDTLS_PRIVATE(unprocessed_len);
347
348 /** Current IV or NONCE_COUNTER for CTR-mode, data unit (or sector) number
349 * for XTS-mode. */
350 unsigned char MBEDTLS_PRIVATE(iv)[MBEDTLS_MAX_IV_LENGTH];
351
352 /** IV size in Bytes, for ciphers with variable-length IVs. */
353 size_t MBEDTLS_PRIVATE(iv_size);
354
355 /** The cipher-specific context. */
356 void *MBEDTLS_PRIVATE(cipher_ctx);
357
358 #if defined(MBEDTLS_CMAC_C)
359 /** CMAC-specific context. */
360 mbedtls_cmac_context_t *MBEDTLS_PRIVATE(cmac_ctx);
361 #endif
362
363 #if defined(MBEDTLS_USE_PSA_CRYPTO)
364 /** Indicates whether the cipher operations should be performed
365 * by Mbed TLS' own crypto library or an external implementation
366 * of the PSA Crypto API.
367 * This is unset if the cipher context was established through
368 * mbedtls_cipher_setup(), and set if it was established through
369 * mbedtls_cipher_setup_psa().
370 */
371 unsigned char MBEDTLS_PRIVATE(psa_enabled);
372 #endif /* MBEDTLS_USE_PSA_CRYPTO */
373
374 } mbedtls_cipher_context_t;
375
376 /**
377 * \brief This function retrieves the list of ciphers supported
378 * by the generic cipher module.
379 *
380 * For any cipher identifier in the returned list, you can
381 * obtain the corresponding generic cipher information structure
382 * via mbedtls_cipher_info_from_type(), which can then be used
383 * to prepare a cipher context via mbedtls_cipher_setup().
384 *
385 *
386 * \return A statically-allocated array of cipher identifiers
387 * of type cipher_type_t. The last entry is zero.
388 */
389 const int *mbedtls_cipher_list( void );
390
391 /**
392 * \brief This function retrieves the cipher-information
393 * structure associated with the given cipher name.
394 *
395 * \param cipher_name Name of the cipher to search for. This must not be
396 * \c NULL.
397 *
398 * \return The cipher information structure associated with the
399 * given \p cipher_name.
400 * \return \c NULL if the associated cipher information is not found.
401 */
402 const mbedtls_cipher_info_t *mbedtls_cipher_info_from_string( const char *cipher_name );
403
404 /**
405 * \brief This function retrieves the cipher-information
406 * structure associated with the given cipher type.
407 *
408 * \param cipher_type Type of the cipher to search for.
409 *
410 * \return The cipher information structure associated with the
411 * given \p cipher_type.
412 * \return \c NULL if the associated cipher information is not found.
413 */
414 const mbedtls_cipher_info_t *mbedtls_cipher_info_from_type( const mbedtls_cipher_type_t cipher_type );
415
416 /**
417 * \brief This function retrieves the cipher-information
418 * structure associated with the given cipher ID,
419 * key size and mode.
420 *
421 * \param cipher_id The ID of the cipher to search for. For example,
422 * #MBEDTLS_CIPHER_ID_AES.
423 * \param key_bitlen The length of the key in bits.
424 * \param mode The cipher mode. For example, #MBEDTLS_MODE_CBC.
425 *
426 * \return The cipher information structure associated with the
427 * given \p cipher_id.
428 * \return \c NULL if the associated cipher information is not found.
429 */
430 const mbedtls_cipher_info_t *mbedtls_cipher_info_from_values( const mbedtls_cipher_id_t cipher_id,
431 int key_bitlen,
432 const mbedtls_cipher_mode_t mode );
433
434 /**
435 * \brief Retrieve the identifier for a cipher info structure.
436 *
437 * \param[in] info The cipher info structure to query.
438 * This may be \c NULL.
439 *
440 * \return The full cipher identifier (\c MBEDTLS_CIPHER_xxx).
441 * \return #MBEDTLS_CIPHER_NONE if \p info is \c NULL.
442 */
mbedtls_cipher_info_get_type(const mbedtls_cipher_info_t * info)443 static inline mbedtls_cipher_type_t mbedtls_cipher_info_get_type(
444 const mbedtls_cipher_info_t *info )
445 {
446 if( info == NULL )
447 return( MBEDTLS_CIPHER_NONE );
448 else
449 return( info->MBEDTLS_PRIVATE(type) );
450 }
451
452 /**
453 * \brief Retrieve the operation mode for a cipher info structure.
454 *
455 * \param[in] info The cipher info structure to query.
456 * This may be \c NULL.
457 *
458 * \return The cipher mode (\c MBEDTLS_MODE_xxx).
459 * \return #MBEDTLS_MODE_NONE if \p info is \c NULL.
460 */
mbedtls_cipher_info_get_mode(const mbedtls_cipher_info_t * info)461 static inline mbedtls_cipher_mode_t mbedtls_cipher_info_get_mode(
462 const mbedtls_cipher_info_t *info )
463 {
464 if( info == NULL )
465 return( MBEDTLS_MODE_NONE );
466 else
467 return( info->MBEDTLS_PRIVATE(mode) );
468 }
469
470 /**
471 * \brief Retrieve the key size for a cipher info structure.
472 *
473 * \param[in] info The cipher info structure to query.
474 * This may be \c NULL.
475 *
476 * \return The key length in bits.
477 * For variable-sized ciphers, this is the default length.
478 * For DES, this includes the parity bits.
479 * \return \c 0 if \p info is \c NULL.
480 */
mbedtls_cipher_info_get_key_bitlen(const mbedtls_cipher_info_t * info)481 static inline size_t mbedtls_cipher_info_get_key_bitlen(
482 const mbedtls_cipher_info_t *info )
483 {
484 if( info == NULL )
485 return( 0 );
486 else
487 return( info->MBEDTLS_PRIVATE(key_bitlen) );
488 }
489
490 /**
491 * \brief Retrieve the human-readable name for a
492 * cipher info structure.
493 *
494 * \param[in] info The cipher info structure to query.
495 * This may be \c NULL.
496 *
497 * \return The cipher name, which is a human readable string,
498 * with static storage duration.
499 * \return \c NULL if \c info is \p NULL.
500 */
mbedtls_cipher_info_get_name(const mbedtls_cipher_info_t * info)501 static inline const char *mbedtls_cipher_info_get_name(
502 const mbedtls_cipher_info_t *info )
503 {
504 if( info == NULL )
505 return( NULL );
506 else
507 return( info->MBEDTLS_PRIVATE(name) );
508 }
509
510 /**
511 * \brief This function returns the size of the IV or nonce
512 * for the cipher info structure, in bytes.
513 *
514 * \param info The cipher info structure. This may be \c NULL.
515 *
516 * \return The recommended IV size.
517 * \return \c 0 for ciphers not using an IV or a nonce.
518 * \return \c 0 if \p info is \c NULL.
519 */
mbedtls_cipher_info_get_iv_size(const mbedtls_cipher_info_t * info)520 static inline size_t mbedtls_cipher_info_get_iv_size(
521 const mbedtls_cipher_info_t *info )
522 {
523 if( info == NULL )
524 return( 0 );
525
526 return( (size_t) info->MBEDTLS_PRIVATE(iv_size) );
527 }
528
529 /**
530 * \brief This function returns the block size of the given
531 * cipher info structure in bytes.
532 *
533 * \param info The cipher info structure. This may be \c NULL.
534 *
535 * \return The block size of the cipher.
536 * \return \c 1 if the cipher is a stream cipher.
537 * \return \c 0 if \p info is \c NULL.
538 */
mbedtls_cipher_info_get_block_size(const mbedtls_cipher_info_t * info)539 static inline size_t mbedtls_cipher_info_get_block_size(
540 const mbedtls_cipher_info_t *info )
541 {
542 if( info == NULL )
543 return( 0 );
544
545 return( (size_t) info->MBEDTLS_PRIVATE(block_size) );
546 }
547
548 /**
549 * \brief This function returns a non-zero value if the key length for
550 * the given cipher is variable.
551 *
552 * \param info The cipher info structure. This may be \c NULL.
553 *
554 * \return Non-zero if the key length is variable, \c 0 otherwise.
555 * \return \c 0 if the given pointer is \c NULL.
556 */
mbedtls_cipher_info_has_variable_key_bitlen(const mbedtls_cipher_info_t * info)557 static inline int mbedtls_cipher_info_has_variable_key_bitlen(
558 const mbedtls_cipher_info_t *info )
559 {
560 if( info == NULL )
561 return( 0 );
562
563 return( info->MBEDTLS_PRIVATE(flags) & MBEDTLS_CIPHER_VARIABLE_KEY_LEN );
564 }
565
566 /**
567 * \brief This function returns a non-zero value if the IV size for
568 * the given cipher is variable.
569 *
570 * \param info The cipher info structure. This may be \c NULL.
571 *
572 * \return Non-zero if the IV size is variable, \c 0 otherwise.
573 * \return \c 0 if the given pointer is \c NULL.
574 */
mbedtls_cipher_info_has_variable_iv_size(const mbedtls_cipher_info_t * info)575 static inline int mbedtls_cipher_info_has_variable_iv_size(
576 const mbedtls_cipher_info_t *info )
577 {
578 if( info == NULL )
579 return( 0 );
580
581 return( info->MBEDTLS_PRIVATE(flags) & MBEDTLS_CIPHER_VARIABLE_IV_LEN );
582 }
583
584 /**
585 * \brief This function initializes a \p cipher_context as NONE.
586 *
587 * \param ctx The context to be initialized. This must not be \c NULL.
588 */
589 void mbedtls_cipher_init( mbedtls_cipher_context_t *ctx );
590
591 /**
592 * \brief This function frees and clears the cipher-specific
593 * context of \p ctx. Freeing \p ctx itself remains the
594 * responsibility of the caller.
595 *
596 * \param ctx The context to be freed. If this is \c NULL, the
597 * function has no effect, otherwise this must point to an
598 * initialized context.
599 */
600 void mbedtls_cipher_free( mbedtls_cipher_context_t *ctx );
601
602
603 /**
604 * \brief This function prepares a cipher context for
605 * use with the given cipher primitive.
606 *
607 * \note After calling this function, you should call
608 * mbedtls_cipher_setkey() and, if the mode uses padding,
609 * mbedtls_cipher_set_padding_mode(), then for each
610 * message to encrypt or decrypt with this key, either:
611 * - mbedtls_cipher_crypt() for one-shot processing with
612 * non-AEAD modes;
613 * - mbedtls_cipher_auth_encrypt_ext() or
614 * mbedtls_cipher_auth_decrypt_ext() for one-shot
615 * processing with AEAD modes or NIST_KW;
616 * - for multi-part processing, see the documentation of
617 * mbedtls_cipher_reset().
618 *
619 * \param ctx The context to prepare. This must be initialized by
620 * a call to mbedtls_cipher_init() first.
621 * \param cipher_info The cipher to use.
622 *
623 * \return \c 0 on success.
624 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
625 * parameter-verification failure.
626 * \return #MBEDTLS_ERR_CIPHER_ALLOC_FAILED if allocation of the
627 * cipher-specific context fails.
628 */
629 int mbedtls_cipher_setup( mbedtls_cipher_context_t *ctx,
630 const mbedtls_cipher_info_t *cipher_info );
631
632 #if defined(MBEDTLS_USE_PSA_CRYPTO)
633 /**
634 * \brief This function initializes a cipher context for
635 * PSA-based use with the given cipher primitive.
636 *
637 * \note See #MBEDTLS_USE_PSA_CRYPTO for information on PSA.
638 *
639 * \param ctx The context to initialize. May not be \c NULL.
640 * \param cipher_info The cipher to use.
641 * \param taglen For AEAD ciphers, the length in bytes of the
642 * authentication tag to use. Subsequent uses of
643 * mbedtls_cipher_auth_encrypt_ext() or
644 * mbedtls_cipher_auth_decrypt_ext() must provide
645 * the same tag length.
646 * For non-AEAD ciphers, the value must be \c 0.
647 *
648 * \return \c 0 on success.
649 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
650 * parameter-verification failure.
651 * \return #MBEDTLS_ERR_CIPHER_ALLOC_FAILED if allocation of the
652 * cipher-specific context fails.
653 */
654 int mbedtls_cipher_setup_psa( mbedtls_cipher_context_t *ctx,
655 const mbedtls_cipher_info_t *cipher_info,
656 size_t taglen );
657 #endif /* MBEDTLS_USE_PSA_CRYPTO */
658
659 /**
660 * \brief This function returns the block size of the given cipher
661 * in bytes.
662 *
663 * \param ctx The context of the cipher.
664 *
665 * \return The block size of the underlying cipher.
666 * \return \c 1 if the cipher is a stream cipher.
667 * \return \c 0 if \p ctx has not been initialized.
668 */
mbedtls_cipher_get_block_size(const mbedtls_cipher_context_t * ctx)669 static inline unsigned int mbedtls_cipher_get_block_size(
670 const mbedtls_cipher_context_t *ctx )
671 {
672 MBEDTLS_INTERNAL_VALIDATE_RET( ctx != NULL, 0 );
673 if( ctx->MBEDTLS_PRIVATE(cipher_info) == NULL )
674 return 0;
675
676 return ctx->MBEDTLS_PRIVATE(cipher_info)->MBEDTLS_PRIVATE(block_size);
677 }
678
679 /**
680 * \brief This function returns the mode of operation for
681 * the cipher. For example, MBEDTLS_MODE_CBC.
682 *
683 * \param ctx The context of the cipher. This must be initialized.
684 *
685 * \return The mode of operation.
686 * \return #MBEDTLS_MODE_NONE if \p ctx has not been initialized.
687 */
mbedtls_cipher_get_cipher_mode(const mbedtls_cipher_context_t * ctx)688 static inline mbedtls_cipher_mode_t mbedtls_cipher_get_cipher_mode(
689 const mbedtls_cipher_context_t *ctx )
690 {
691 MBEDTLS_INTERNAL_VALIDATE_RET( ctx != NULL, MBEDTLS_MODE_NONE );
692 if( ctx->MBEDTLS_PRIVATE(cipher_info) == NULL )
693 return MBEDTLS_MODE_NONE;
694
695 return ctx->MBEDTLS_PRIVATE(cipher_info)->MBEDTLS_PRIVATE(mode);
696 }
697
698 /**
699 * \brief This function returns the size of the IV or nonce
700 * of the cipher, in Bytes.
701 *
702 * \param ctx The context of the cipher. This must be initialized.
703 *
704 * \return The recommended IV size if no IV has been set.
705 * \return \c 0 for ciphers not using an IV or a nonce.
706 * \return The actual size if an IV has been set.
707 */
mbedtls_cipher_get_iv_size(const mbedtls_cipher_context_t * ctx)708 static inline int mbedtls_cipher_get_iv_size(
709 const mbedtls_cipher_context_t *ctx )
710 {
711 MBEDTLS_INTERNAL_VALIDATE_RET( ctx != NULL, 0 );
712 if( ctx->MBEDTLS_PRIVATE(cipher_info) == NULL )
713 return 0;
714
715 if( ctx->MBEDTLS_PRIVATE(iv_size) != 0 )
716 return (int) ctx->MBEDTLS_PRIVATE(iv_size);
717
718 return (int) ctx->MBEDTLS_PRIVATE(cipher_info)->MBEDTLS_PRIVATE(iv_size);
719 }
720
721 /**
722 * \brief This function returns the type of the given cipher.
723 *
724 * \param ctx The context of the cipher. This must be initialized.
725 *
726 * \return The type of the cipher.
727 * \return #MBEDTLS_CIPHER_NONE if \p ctx has not been initialized.
728 */
mbedtls_cipher_get_type(const mbedtls_cipher_context_t * ctx)729 static inline mbedtls_cipher_type_t mbedtls_cipher_get_type(
730 const mbedtls_cipher_context_t *ctx )
731 {
732 MBEDTLS_INTERNAL_VALIDATE_RET(
733 ctx != NULL, MBEDTLS_CIPHER_NONE );
734 if( ctx->MBEDTLS_PRIVATE(cipher_info) == NULL )
735 return MBEDTLS_CIPHER_NONE;
736
737 return ctx->MBEDTLS_PRIVATE(cipher_info)->MBEDTLS_PRIVATE(type);
738 }
739
740 /**
741 * \brief This function returns the name of the given cipher
742 * as a string.
743 *
744 * \param ctx The context of the cipher. This must be initialized.
745 *
746 * \return The name of the cipher.
747 * \return NULL if \p ctx has not been not initialized.
748 */
mbedtls_cipher_get_name(const mbedtls_cipher_context_t * ctx)749 static inline const char *mbedtls_cipher_get_name(
750 const mbedtls_cipher_context_t *ctx )
751 {
752 MBEDTLS_INTERNAL_VALIDATE_RET( ctx != NULL, 0 );
753 if( ctx->MBEDTLS_PRIVATE(cipher_info) == NULL )
754 return 0;
755
756 return ctx->MBEDTLS_PRIVATE(cipher_info)->MBEDTLS_PRIVATE(name);
757 }
758
759 /**
760 * \brief This function returns the key length of the cipher.
761 *
762 * \param ctx The context of the cipher. This must be initialized.
763 *
764 * \return The key length of the cipher in bits.
765 * \return #MBEDTLS_KEY_LENGTH_NONE if ctx \p has not been
766 * initialized.
767 */
mbedtls_cipher_get_key_bitlen(const mbedtls_cipher_context_t * ctx)768 static inline int mbedtls_cipher_get_key_bitlen(
769 const mbedtls_cipher_context_t *ctx )
770 {
771 MBEDTLS_INTERNAL_VALIDATE_RET(
772 ctx != NULL, MBEDTLS_KEY_LENGTH_NONE );
773 if( ctx->MBEDTLS_PRIVATE(cipher_info) == NULL )
774 return MBEDTLS_KEY_LENGTH_NONE;
775
776 return (int) ctx->MBEDTLS_PRIVATE(cipher_info)->MBEDTLS_PRIVATE(key_bitlen);
777 }
778
779 /**
780 * \brief This function returns the operation of the given cipher.
781 *
782 * \param ctx The context of the cipher. This must be initialized.
783 *
784 * \return The type of operation: #MBEDTLS_ENCRYPT or #MBEDTLS_DECRYPT.
785 * \return #MBEDTLS_OPERATION_NONE if \p ctx has not been initialized.
786 */
mbedtls_cipher_get_operation(const mbedtls_cipher_context_t * ctx)787 static inline mbedtls_operation_t mbedtls_cipher_get_operation(
788 const mbedtls_cipher_context_t *ctx )
789 {
790 MBEDTLS_INTERNAL_VALIDATE_RET(
791 ctx != NULL, MBEDTLS_OPERATION_NONE );
792 if( ctx->MBEDTLS_PRIVATE(cipher_info) == NULL )
793 return MBEDTLS_OPERATION_NONE;
794
795 return ctx->MBEDTLS_PRIVATE(operation);
796 }
797
798 /**
799 * \brief This function sets the key to use with the given context.
800 *
801 * \param ctx The generic cipher context. This must be initialized and
802 * bound to a cipher information structure.
803 * \param key The key to use. This must be a readable buffer of at
804 * least \p key_bitlen Bits.
805 * \param key_bitlen The key length to use, in Bits.
806 * \param operation The operation that the key will be used for:
807 * #MBEDTLS_ENCRYPT or #MBEDTLS_DECRYPT.
808 *
809 * \return \c 0 on success.
810 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
811 * parameter-verification failure.
812 * \return A cipher-specific error code on failure.
813 */
814 int mbedtls_cipher_setkey( mbedtls_cipher_context_t *ctx,
815 const unsigned char *key,
816 int key_bitlen,
817 const mbedtls_operation_t operation );
818
819 #if defined(MBEDTLS_CIPHER_MODE_WITH_PADDING)
820 /**
821 * \brief This function sets the padding mode, for cipher modes
822 * that use padding.
823 *
824 * The default passing mode is PKCS7 padding.
825 *
826 * \param ctx The generic cipher context. This must be initialized and
827 * bound to a cipher information structure.
828 * \param mode The padding mode.
829 *
830 * \return \c 0 on success.
831 * \return #MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE
832 * if the selected padding mode is not supported.
833 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA if the cipher mode
834 * does not support padding.
835 */
836 int mbedtls_cipher_set_padding_mode( mbedtls_cipher_context_t *ctx,
837 mbedtls_cipher_padding_t mode );
838 #endif /* MBEDTLS_CIPHER_MODE_WITH_PADDING */
839
840 /**
841 * \brief This function sets the initialization vector (IV)
842 * or nonce.
843 *
844 * \note Some ciphers do not use IVs nor nonce. For these
845 * ciphers, this function has no effect.
846 *
847 * \param ctx The generic cipher context. This must be initialized and
848 * bound to a cipher information structure.
849 * \param iv The IV to use, or NONCE_COUNTER for CTR-mode ciphers. This
850 * must be a readable buffer of at least \p iv_len Bytes.
851 * \param iv_len The IV length for ciphers with variable-size IV.
852 * This parameter is discarded by ciphers with fixed-size IV.
853 *
854 * \return \c 0 on success.
855 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
856 * parameter-verification failure.
857 */
858 int mbedtls_cipher_set_iv( mbedtls_cipher_context_t *ctx,
859 const unsigned char *iv,
860 size_t iv_len );
861
862 /**
863 * \brief This function resets the cipher state.
864 *
865 * \note With non-AEAD ciphers, the order of calls for each message
866 * is as follows:
867 * 1. mbedtls_cipher_set_iv() if the mode uses an IV/nonce.
868 * 2. mbedtls_cipher_reset()
869 * 3. mbedtls_cipher_update() one or more times
870 * 4. mbedtls_cipher_finish()
871 * .
872 * This sequence can be repeated to encrypt or decrypt multiple
873 * messages with the same key.
874 *
875 * \note With AEAD ciphers, the order of calls for each message
876 * is as follows:
877 * 1. mbedtls_cipher_set_iv() if the mode uses an IV/nonce.
878 * 2. mbedtls_cipher_reset()
879 * 3. mbedtls_cipher_update_ad()
880 * 4. mbedtls_cipher_update() one or more times
881 * 5. mbedtls_cipher_finish()
882 * 6. mbedtls_cipher_check_tag() (for decryption) or
883 * mbedtls_cipher_write_tag() (for encryption).
884 * .
885 * This sequence can be repeated to encrypt or decrypt multiple
886 * messages with the same key.
887 *
888 * \param ctx The generic cipher context. This must be bound to a key.
889 *
890 * \return \c 0 on success.
891 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
892 * parameter-verification failure.
893 */
894 int mbedtls_cipher_reset( mbedtls_cipher_context_t *ctx );
895
896 #if defined(MBEDTLS_GCM_C) || defined(MBEDTLS_CHACHAPOLY_C)
897 /**
898 * \brief This function adds additional data for AEAD ciphers.
899 * Currently supported with GCM and ChaCha20+Poly1305.
900 *
901 * \param ctx The generic cipher context. This must be initialized.
902 * \param ad The additional data to use. This must be a readable
903 * buffer of at least \p ad_len Bytes.
904 * \param ad_len The length of \p ad in Bytes.
905 *
906 * \return \c 0 on success.
907 * \return A specific error code on failure.
908 */
909 int mbedtls_cipher_update_ad( mbedtls_cipher_context_t *ctx,
910 const unsigned char *ad, size_t ad_len );
911 #endif /* MBEDTLS_GCM_C || MBEDTLS_CHACHAPOLY_C */
912
913 /**
914 * \brief The generic cipher update function. It encrypts or
915 * decrypts using the given cipher context. Writes as
916 * many block-sized blocks of data as possible to output.
917 * Any data that cannot be written immediately is either
918 * added to the next block, or flushed when
919 * mbedtls_cipher_finish() is called.
920 * Exception: For MBEDTLS_MODE_ECB, expects a single block
921 * in size. For example, 16 Bytes for AES.
922 *
923 * \param ctx The generic cipher context. This must be initialized and
924 * bound to a key.
925 * \param input The buffer holding the input data. This must be a
926 * readable buffer of at least \p ilen Bytes.
927 * \param ilen The length of the input data.
928 * \param output The buffer for the output data. This must be able to
929 * hold at least `ilen + block_size`. This must not be the
930 * same buffer as \p input.
931 * \param olen The length of the output data, to be updated with the
932 * actual number of Bytes written. This must not be
933 * \c NULL.
934 *
935 * \return \c 0 on success.
936 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
937 * parameter-verification failure.
938 * \return #MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE on an
939 * unsupported mode for a cipher.
940 * \return A cipher-specific error code on failure.
941 */
942 int mbedtls_cipher_update( mbedtls_cipher_context_t *ctx,
943 const unsigned char *input,
944 size_t ilen, unsigned char *output,
945 size_t *olen );
946
947 /**
948 * \brief The generic cipher finalization function. If data still
949 * needs to be flushed from an incomplete block, the data
950 * contained in it is padded to the size of
951 * the last block, and written to the \p output buffer.
952 *
953 * \param ctx The generic cipher context. This must be initialized and
954 * bound to a key.
955 * \param output The buffer to write data to. This needs to be a writable
956 * buffer of at least \p block_size Bytes.
957 * \param olen The length of the data written to the \p output buffer.
958 * This may not be \c NULL.
959 *
960 * \return \c 0 on success.
961 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
962 * parameter-verification failure.
963 * \return #MBEDTLS_ERR_CIPHER_FULL_BLOCK_EXPECTED on decryption
964 * expecting a full block but not receiving one.
965 * \return #MBEDTLS_ERR_CIPHER_INVALID_PADDING on invalid padding
966 * while decrypting.
967 * \return A cipher-specific error code on failure.
968 */
969 int mbedtls_cipher_finish( mbedtls_cipher_context_t *ctx,
970 unsigned char *output, size_t *olen );
971
972 #if defined(MBEDTLS_GCM_C) || defined(MBEDTLS_CHACHAPOLY_C)
973 /**
974 * \brief This function writes a tag for AEAD ciphers.
975 * Currently supported with GCM and ChaCha20+Poly1305.
976 * This must be called after mbedtls_cipher_finish().
977 *
978 * \param ctx The generic cipher context. This must be initialized,
979 * bound to a key, and have just completed a cipher
980 * operation through mbedtls_cipher_finish() the tag for
981 * which should be written.
982 * \param tag The buffer to write the tag to. This must be a writable
983 * buffer of at least \p tag_len Bytes.
984 * \param tag_len The length of the tag to write.
985 *
986 * \return \c 0 on success.
987 * \return A specific error code on failure.
988 */
989 int mbedtls_cipher_write_tag( mbedtls_cipher_context_t *ctx,
990 unsigned char *tag, size_t tag_len );
991
992 /**
993 * \brief This function checks the tag for AEAD ciphers.
994 * Currently supported with GCM and ChaCha20+Poly1305.
995 * This must be called after mbedtls_cipher_finish().
996 *
997 * \param ctx The generic cipher context. This must be initialized.
998 * \param tag The buffer holding the tag. This must be a readable
999 * buffer of at least \p tag_len Bytes.
1000 * \param tag_len The length of the tag to check.
1001 *
1002 * \return \c 0 on success.
1003 * \return A specific error code on failure.
1004 */
1005 int mbedtls_cipher_check_tag( mbedtls_cipher_context_t *ctx,
1006 const unsigned char *tag, size_t tag_len );
1007 #endif /* MBEDTLS_GCM_C || MBEDTLS_CHACHAPOLY_C */
1008
1009 /**
1010 * \brief The generic all-in-one encryption/decryption function,
1011 * for all ciphers except AEAD constructs.
1012 *
1013 * \param ctx The generic cipher context. This must be initialized.
1014 * \param iv The IV to use, or NONCE_COUNTER for CTR-mode ciphers.
1015 * This must be a readable buffer of at least \p iv_len
1016 * Bytes.
1017 * \param iv_len The IV length for ciphers with variable-size IV.
1018 * This parameter is discarded by ciphers with fixed-size
1019 * IV.
1020 * \param input The buffer holding the input data. This must be a
1021 * readable buffer of at least \p ilen Bytes.
1022 * \param ilen The length of the input data in Bytes.
1023 * \param output The buffer for the output data. This must be able to
1024 * hold at least `ilen + block_size`. This must not be the
1025 * same buffer as \p input.
1026 * \param olen The length of the output data, to be updated with the
1027 * actual number of Bytes written. This must not be
1028 * \c NULL.
1029 *
1030 * \note Some ciphers do not use IVs nor nonce. For these
1031 * ciphers, use \p iv = NULL and \p iv_len = 0.
1032 *
1033 * \return \c 0 on success.
1034 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
1035 * parameter-verification failure.
1036 * \return #MBEDTLS_ERR_CIPHER_FULL_BLOCK_EXPECTED on decryption
1037 * expecting a full block but not receiving one.
1038 * \return #MBEDTLS_ERR_CIPHER_INVALID_PADDING on invalid padding
1039 * while decrypting.
1040 * \return A cipher-specific error code on failure.
1041 */
1042 int mbedtls_cipher_crypt( mbedtls_cipher_context_t *ctx,
1043 const unsigned char *iv, size_t iv_len,
1044 const unsigned char *input, size_t ilen,
1045 unsigned char *output, size_t *olen );
1046
1047 #if defined(MBEDTLS_CIPHER_MODE_AEAD) || defined(MBEDTLS_NIST_KW_C)
1048 /**
1049 * \brief The authenticated encryption (AEAD/NIST_KW) function.
1050 *
1051 * \note For AEAD modes, the tag will be appended to the
1052 * ciphertext, as recommended by RFC 5116.
1053 * (NIST_KW doesn't have a separate tag.)
1054 *
1055 * \param ctx The generic cipher context. This must be initialized and
1056 * bound to a key, with an AEAD algorithm or NIST_KW.
1057 * \param iv The nonce to use. This must be a readable buffer of
1058 * at least \p iv_len Bytes and may be \c NULL if \p
1059 * iv_len is \c 0.
1060 * \param iv_len The length of the nonce. For AEAD ciphers, this must
1061 * satisfy the constraints imposed by the cipher used.
1062 * For NIST_KW, this must be \c 0.
1063 * \param ad The additional data to authenticate. This must be a
1064 * readable buffer of at least \p ad_len Bytes, and may
1065 * be \c NULL is \p ad_len is \c 0.
1066 * \param ad_len The length of \p ad. For NIST_KW, this must be \c 0.
1067 * \param input The buffer holding the input data. This must be a
1068 * readable buffer of at least \p ilen Bytes, and may be
1069 * \c NULL if \p ilen is \c 0.
1070 * \param ilen The length of the input data.
1071 * \param output The buffer for the output data. This must be a
1072 * writable buffer of at least \p output_len Bytes, and
1073 * must not be \c NULL.
1074 * \param output_len The length of the \p output buffer in Bytes. For AEAD
1075 * ciphers, this must be at least \p ilen + \p tag_len.
1076 * For NIST_KW, this must be at least \p ilen + 8
1077 * (rounded up to a multiple of 8 if KWP is used);
1078 * \p ilen + 15 is always a safe value.
1079 * \param olen This will be filled with the actual number of Bytes
1080 * written to the \p output buffer. This must point to a
1081 * writable object of type \c size_t.
1082 * \param tag_len The desired length of the authentication tag. For AEAD
1083 * ciphers, this must match the constraints imposed by
1084 * the cipher used, and in particular must not be \c 0.
1085 * For NIST_KW, this must be \c 0.
1086 *
1087 * \return \c 0 on success.
1088 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
1089 * parameter-verification failure.
1090 * \return A cipher-specific error code on failure.
1091 */
1092 int mbedtls_cipher_auth_encrypt_ext( mbedtls_cipher_context_t *ctx,
1093 const unsigned char *iv, size_t iv_len,
1094 const unsigned char *ad, size_t ad_len,
1095 const unsigned char *input, size_t ilen,
1096 unsigned char *output, size_t output_len,
1097 size_t *olen, size_t tag_len );
1098
1099 /**
1100 * \brief The authenticated encryption (AEAD/NIST_KW) function.
1101 *
1102 * \note If the data is not authentic, then the output buffer
1103 * is zeroed out to prevent the unauthentic plaintext being
1104 * used, making this interface safer.
1105 *
1106 * \note For AEAD modes, the tag must be appended to the
1107 * ciphertext, as recommended by RFC 5116.
1108 * (NIST_KW doesn't have a separate tag.)
1109 *
1110 * \param ctx The generic cipher context. This must be initialized and
1111 * bound to a key, with an AEAD algorithm or NIST_KW.
1112 * \param iv The nonce to use. This must be a readable buffer of
1113 * at least \p iv_len Bytes and may be \c NULL if \p
1114 * iv_len is \c 0.
1115 * \param iv_len The length of the nonce. For AEAD ciphers, this must
1116 * satisfy the constraints imposed by the cipher used.
1117 * For NIST_KW, this must be \c 0.
1118 * \param ad The additional data to authenticate. This must be a
1119 * readable buffer of at least \p ad_len Bytes, and may
1120 * be \c NULL is \p ad_len is \c 0.
1121 * \param ad_len The length of \p ad. For NIST_KW, this must be \c 0.
1122 * \param input The buffer holding the input data. This must be a
1123 * readable buffer of at least \p ilen Bytes, and may be
1124 * \c NULL if \p ilen is \c 0.
1125 * \param ilen The length of the input data. For AEAD ciphers this
1126 * must be at least \p tag_len. For NIST_KW this must be
1127 * at least \c 8.
1128 * \param output The buffer for the output data. This must be a
1129 * writable buffer of at least \p output_len Bytes, and
1130 * may be \c NULL if \p output_len is \c 0.
1131 * \param output_len The length of the \p output buffer in Bytes. For AEAD
1132 * ciphers, this must be at least \p ilen - \p tag_len.
1133 * For NIST_KW, this must be at least \p ilen - 8.
1134 * \param olen This will be filled with the actual number of Bytes
1135 * written to the \p output buffer. This must point to a
1136 * writable object of type \c size_t.
1137 * \param tag_len The actual length of the authentication tag. For AEAD
1138 * ciphers, this must match the constraints imposed by
1139 * the cipher used, and in particular must not be \c 0.
1140 * For NIST_KW, this must be \c 0.
1141 *
1142 * \return \c 0 on success.
1143 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
1144 * parameter-verification failure.
1145 * \return #MBEDTLS_ERR_CIPHER_AUTH_FAILED if data is not authentic.
1146 * \return A cipher-specific error code on failure.
1147 */
1148 int mbedtls_cipher_auth_decrypt_ext( mbedtls_cipher_context_t *ctx,
1149 const unsigned char *iv, size_t iv_len,
1150 const unsigned char *ad, size_t ad_len,
1151 const unsigned char *input, size_t ilen,
1152 unsigned char *output, size_t output_len,
1153 size_t *olen, size_t tag_len );
1154 #endif /* MBEDTLS_CIPHER_MODE_AEAD || MBEDTLS_NIST_KW_C */
1155 #ifdef __cplusplus
1156 }
1157 #endif
1158
1159 #endif /* MBEDTLS_CIPHER_H */
1160