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
30 #if !defined(MBEDTLS_CONFIG_FILE)
31 #include "mbedtls/config.h"
32 #else
33 #include MBEDTLS_CONFIG_FILE
34 #endif
35
36 #include <stddef.h>
37 #include "mbedtls/platform_util.h"
38
39 #if defined(MBEDTLS_GCM_C) || defined(MBEDTLS_CCM_C) || defined(MBEDTLS_CHACHAPOLY_C)
40 #define MBEDTLS_CIPHER_MODE_AEAD
41 #endif
42
43 #if defined(MBEDTLS_CIPHER_MODE_CBC)
44 #define MBEDTLS_CIPHER_MODE_WITH_PADDING
45 #endif
46
47 #if defined(MBEDTLS_ARC4_C) || defined(MBEDTLS_CIPHER_NULL_CIPHER) || \
48 defined(MBEDTLS_CHACHA20_C)
49 #define MBEDTLS_CIPHER_MODE_STREAM
50 #endif
51
52 #if ( defined(__ARMCC_VERSION) || defined(_MSC_VER) ) && \
53 !defined(inline) && !defined(__cplusplus)
54 #define inline __inline
55 #endif
56
57 /** The selected feature is not available. */
58 #define MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE -0x6080
59 /** Bad input parameters. */
60 #define MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA -0x6100
61 /** Failed to allocate memory. */
62 #define MBEDTLS_ERR_CIPHER_ALLOC_FAILED -0x6180
63 /** Input data contains invalid padding and is rejected. */
64 #define MBEDTLS_ERR_CIPHER_INVALID_PADDING -0x6200
65 /** Decryption of block requires a full block. */
66 #define MBEDTLS_ERR_CIPHER_FULL_BLOCK_EXPECTED -0x6280
67 /** Authentication failed (for AEAD modes). */
68 #define MBEDTLS_ERR_CIPHER_AUTH_FAILED -0x6300
69 /** The context is invalid. For example, because it was freed. */
70 #define MBEDTLS_ERR_CIPHER_INVALID_CONTEXT -0x6380
71
72 /* MBEDTLS_ERR_CIPHER_HW_ACCEL_FAILED is deprecated and should not be used. */
73 /** Cipher hardware accelerator failed. */
74 #define MBEDTLS_ERR_CIPHER_HW_ACCEL_FAILED -0x6400
75
76 #define MBEDTLS_CIPHER_VARIABLE_IV_LEN 0x01 /**< Cipher accepts IVs of variable length. */
77 #define MBEDTLS_CIPHER_VARIABLE_KEY_LEN 0x02 /**< Cipher accepts keys of variable length. */
78
79 #ifdef __cplusplus
80 extern "C" {
81 #endif
82
83 /**
84 * \brief Supported cipher types.
85 *
86 * \warning RC4 and DES are considered weak ciphers and their use
87 * constitutes a security risk. Arm recommends considering stronger
88 * ciphers instead.
89 */
90 typedef enum {
91 MBEDTLS_CIPHER_ID_NONE = 0, /**< Placeholder to mark the end of cipher ID lists. */
92 MBEDTLS_CIPHER_ID_NULL, /**< The identity cipher, treated as a stream cipher. */
93 MBEDTLS_CIPHER_ID_AES, /**< The AES cipher. */
94 MBEDTLS_CIPHER_ID_DES, /**< The DES cipher. */
95 MBEDTLS_CIPHER_ID_3DES, /**< The Triple DES cipher. */
96 MBEDTLS_CIPHER_ID_CAMELLIA, /**< The Camellia cipher. */
97 MBEDTLS_CIPHER_ID_BLOWFISH, /**< The Blowfish cipher. */
98 MBEDTLS_CIPHER_ID_ARC4, /**< The RC4 cipher. */
99 MBEDTLS_CIPHER_ID_ARIA, /**< The Aria cipher. */
100 MBEDTLS_CIPHER_ID_CHACHA20, /**< The ChaCha20 cipher. */
101 } mbedtls_cipher_id_t;
102
103 /**
104 * \brief Supported {cipher type, cipher mode} pairs.
105 *
106 * \warning RC4 and DES are considered weak ciphers and their use
107 * constitutes a security risk. Arm recommends considering stronger
108 * ciphers instead.
109 */
110 typedef enum {
111 MBEDTLS_CIPHER_NONE = 0, /**< Placeholder to mark the end of cipher-pair lists. */
112 MBEDTLS_CIPHER_NULL, /**< The identity stream cipher. */
113 MBEDTLS_CIPHER_AES_128_ECB, /**< AES cipher with 128-bit ECB mode. */
114 MBEDTLS_CIPHER_AES_192_ECB, /**< AES cipher with 192-bit ECB mode. */
115 MBEDTLS_CIPHER_AES_256_ECB, /**< AES cipher with 256-bit ECB mode. */
116 MBEDTLS_CIPHER_AES_128_CBC, /**< AES cipher with 128-bit CBC mode. */
117 MBEDTLS_CIPHER_AES_192_CBC, /**< AES cipher with 192-bit CBC mode. */
118 MBEDTLS_CIPHER_AES_256_CBC, /**< AES cipher with 256-bit CBC mode. */
119 MBEDTLS_CIPHER_AES_128_CFB128, /**< AES cipher with 128-bit CFB128 mode. */
120 MBEDTLS_CIPHER_AES_192_CFB128, /**< AES cipher with 192-bit CFB128 mode. */
121 MBEDTLS_CIPHER_AES_256_CFB128, /**< AES cipher with 256-bit CFB128 mode. */
122 MBEDTLS_CIPHER_AES_128_CTR, /**< AES cipher with 128-bit CTR mode. */
123 MBEDTLS_CIPHER_AES_192_CTR, /**< AES cipher with 192-bit CTR mode. */
124 MBEDTLS_CIPHER_AES_256_CTR, /**< AES cipher with 256-bit CTR mode. */
125 MBEDTLS_CIPHER_AES_128_GCM, /**< AES cipher with 128-bit GCM mode. */
126 MBEDTLS_CIPHER_AES_192_GCM, /**< AES cipher with 192-bit GCM mode. */
127 MBEDTLS_CIPHER_AES_256_GCM, /**< AES cipher with 256-bit GCM mode. */
128 MBEDTLS_CIPHER_CAMELLIA_128_ECB, /**< Camellia cipher with 128-bit ECB mode. */
129 MBEDTLS_CIPHER_CAMELLIA_192_ECB, /**< Camellia cipher with 192-bit ECB mode. */
130 MBEDTLS_CIPHER_CAMELLIA_256_ECB, /**< Camellia cipher with 256-bit ECB mode. */
131 MBEDTLS_CIPHER_CAMELLIA_128_CBC, /**< Camellia cipher with 128-bit CBC mode. */
132 MBEDTLS_CIPHER_CAMELLIA_192_CBC, /**< Camellia cipher with 192-bit CBC mode. */
133 MBEDTLS_CIPHER_CAMELLIA_256_CBC, /**< Camellia cipher with 256-bit CBC mode. */
134 MBEDTLS_CIPHER_CAMELLIA_128_CFB128, /**< Camellia cipher with 128-bit CFB128 mode. */
135 MBEDTLS_CIPHER_CAMELLIA_192_CFB128, /**< Camellia cipher with 192-bit CFB128 mode. */
136 MBEDTLS_CIPHER_CAMELLIA_256_CFB128, /**< Camellia cipher with 256-bit CFB128 mode. */
137 MBEDTLS_CIPHER_CAMELLIA_128_CTR, /**< Camellia cipher with 128-bit CTR mode. */
138 MBEDTLS_CIPHER_CAMELLIA_192_CTR, /**< Camellia cipher with 192-bit CTR mode. */
139 MBEDTLS_CIPHER_CAMELLIA_256_CTR, /**< Camellia cipher with 256-bit CTR mode. */
140 MBEDTLS_CIPHER_CAMELLIA_128_GCM, /**< Camellia cipher with 128-bit GCM mode. */
141 MBEDTLS_CIPHER_CAMELLIA_192_GCM, /**< Camellia cipher with 192-bit GCM mode. */
142 MBEDTLS_CIPHER_CAMELLIA_256_GCM, /**< Camellia cipher with 256-bit GCM mode. */
143 MBEDTLS_CIPHER_DES_ECB, /**< DES cipher with ECB mode. */
144 MBEDTLS_CIPHER_DES_CBC, /**< DES cipher with CBC mode. */
145 MBEDTLS_CIPHER_DES_EDE_ECB, /**< DES cipher with EDE ECB mode. */
146 MBEDTLS_CIPHER_DES_EDE_CBC, /**< DES cipher with EDE CBC mode. */
147 MBEDTLS_CIPHER_DES_EDE3_ECB, /**< DES cipher with EDE3 ECB mode. */
148 MBEDTLS_CIPHER_DES_EDE3_CBC, /**< DES cipher with EDE3 CBC mode. */
149 MBEDTLS_CIPHER_BLOWFISH_ECB, /**< Blowfish cipher with ECB mode. */
150 MBEDTLS_CIPHER_BLOWFISH_CBC, /**< Blowfish cipher with CBC mode. */
151 MBEDTLS_CIPHER_BLOWFISH_CFB64, /**< Blowfish cipher with CFB64 mode. */
152 MBEDTLS_CIPHER_BLOWFISH_CTR, /**< Blowfish cipher with CTR mode. */
153 MBEDTLS_CIPHER_ARC4_128, /**< RC4 cipher with 128-bit mode. */
154 MBEDTLS_CIPHER_AES_128_CCM, /**< AES cipher with 128-bit CCM mode. */
155 MBEDTLS_CIPHER_AES_192_CCM, /**< AES cipher with 192-bit CCM mode. */
156 MBEDTLS_CIPHER_AES_256_CCM, /**< AES cipher with 256-bit CCM mode. */
157 MBEDTLS_CIPHER_CAMELLIA_128_CCM, /**< Camellia cipher with 128-bit CCM mode. */
158 MBEDTLS_CIPHER_CAMELLIA_192_CCM, /**< Camellia cipher with 192-bit CCM mode. */
159 MBEDTLS_CIPHER_CAMELLIA_256_CCM, /**< Camellia cipher with 256-bit CCM mode. */
160 MBEDTLS_CIPHER_ARIA_128_ECB, /**< Aria cipher with 128-bit key and ECB mode. */
161 MBEDTLS_CIPHER_ARIA_192_ECB, /**< Aria cipher with 192-bit key and ECB mode. */
162 MBEDTLS_CIPHER_ARIA_256_ECB, /**< Aria cipher with 256-bit key and ECB mode. */
163 MBEDTLS_CIPHER_ARIA_128_CBC, /**< Aria cipher with 128-bit key and CBC mode. */
164 MBEDTLS_CIPHER_ARIA_192_CBC, /**< Aria cipher with 192-bit key and CBC mode. */
165 MBEDTLS_CIPHER_ARIA_256_CBC, /**< Aria cipher with 256-bit key and CBC mode. */
166 MBEDTLS_CIPHER_ARIA_128_CFB128, /**< Aria cipher with 128-bit key and CFB-128 mode. */
167 MBEDTLS_CIPHER_ARIA_192_CFB128, /**< Aria cipher with 192-bit key and CFB-128 mode. */
168 MBEDTLS_CIPHER_ARIA_256_CFB128, /**< Aria cipher with 256-bit key and CFB-128 mode. */
169 MBEDTLS_CIPHER_ARIA_128_CTR, /**< Aria cipher with 128-bit key and CTR mode. */
170 MBEDTLS_CIPHER_ARIA_192_CTR, /**< Aria cipher with 192-bit key and CTR mode. */
171 MBEDTLS_CIPHER_ARIA_256_CTR, /**< Aria cipher with 256-bit key and CTR mode. */
172 MBEDTLS_CIPHER_ARIA_128_GCM, /**< Aria cipher with 128-bit key and GCM mode. */
173 MBEDTLS_CIPHER_ARIA_192_GCM, /**< Aria cipher with 192-bit key and GCM mode. */
174 MBEDTLS_CIPHER_ARIA_256_GCM, /**< Aria cipher with 256-bit key and GCM mode. */
175 MBEDTLS_CIPHER_ARIA_128_CCM, /**< Aria cipher with 128-bit key and CCM mode. */
176 MBEDTLS_CIPHER_ARIA_192_CCM, /**< Aria cipher with 192-bit key and CCM mode. */
177 MBEDTLS_CIPHER_ARIA_256_CCM, /**< Aria cipher with 256-bit key and CCM mode. */
178 MBEDTLS_CIPHER_AES_128_OFB, /**< AES 128-bit cipher in OFB mode. */
179 MBEDTLS_CIPHER_AES_192_OFB, /**< AES 192-bit cipher in OFB mode. */
180 MBEDTLS_CIPHER_AES_256_OFB, /**< AES 256-bit cipher in OFB mode. */
181 MBEDTLS_CIPHER_AES_128_XTS, /**< AES 128-bit cipher in XTS block mode. */
182 MBEDTLS_CIPHER_AES_256_XTS, /**< AES 256-bit cipher in XTS block mode. */
183 MBEDTLS_CIPHER_CHACHA20, /**< ChaCha20 stream cipher. */
184 MBEDTLS_CIPHER_CHACHA20_POLY1305, /**< ChaCha20-Poly1305 AEAD cipher. */
185 MBEDTLS_CIPHER_AES_128_KW, /**< AES cipher with 128-bit NIST KW mode. */
186 MBEDTLS_CIPHER_AES_192_KW, /**< AES cipher with 192-bit NIST KW mode. */
187 MBEDTLS_CIPHER_AES_256_KW, /**< AES cipher with 256-bit NIST KW mode. */
188 MBEDTLS_CIPHER_AES_128_KWP, /**< AES cipher with 128-bit NIST KWP mode. */
189 MBEDTLS_CIPHER_AES_192_KWP, /**< AES cipher with 192-bit NIST KWP mode. */
190 MBEDTLS_CIPHER_AES_256_KWP, /**< AES cipher with 256-bit NIST KWP mode. */
191 } mbedtls_cipher_type_t;
192
193 /** Supported cipher modes. */
194 typedef enum {
195 MBEDTLS_MODE_NONE = 0, /**< None. */
196 MBEDTLS_MODE_ECB, /**< The ECB cipher mode. */
197 MBEDTLS_MODE_CBC, /**< The CBC cipher mode. */
198 MBEDTLS_MODE_CFB, /**< The CFB cipher mode. */
199 MBEDTLS_MODE_OFB, /**< The OFB cipher mode. */
200 MBEDTLS_MODE_CTR, /**< The CTR cipher mode. */
201 MBEDTLS_MODE_GCM, /**< The GCM cipher mode. */
202 MBEDTLS_MODE_STREAM, /**< The stream cipher mode. */
203 MBEDTLS_MODE_CCM, /**< The CCM cipher mode. */
204 MBEDTLS_MODE_XTS, /**< The XTS cipher mode. */
205 MBEDTLS_MODE_CHACHAPOLY, /**< The ChaCha-Poly cipher mode. */
206 MBEDTLS_MODE_KW, /**< The SP800-38F KW mode */
207 MBEDTLS_MODE_KWP, /**< The SP800-38F KWP mode */
208 } mbedtls_cipher_mode_t;
209
210 /** Supported cipher padding types. */
211 typedef enum {
212 MBEDTLS_PADDING_PKCS7 = 0, /**< PKCS7 padding (default). */
213 MBEDTLS_PADDING_ONE_AND_ZEROS, /**< ISO/IEC 7816-4 padding. */
214 MBEDTLS_PADDING_ZEROS_AND_LEN, /**< ANSI X.923 padding. */
215 MBEDTLS_PADDING_ZEROS, /**< Zero padding (not reversible). */
216 MBEDTLS_PADDING_NONE, /**< Never pad (full blocks only). */
217 } mbedtls_cipher_padding_t;
218
219 /** Type of operation. */
220 typedef enum {
221 MBEDTLS_OPERATION_NONE = -1,
222 MBEDTLS_DECRYPT = 0,
223 MBEDTLS_ENCRYPT,
224 } mbedtls_operation_t;
225
226 enum {
227 /** Undefined key length. */
228 MBEDTLS_KEY_LENGTH_NONE = 0,
229 /** Key length, in bits (including parity), for DES keys. */
230 MBEDTLS_KEY_LENGTH_DES = 64,
231 /** Key length in bits, including parity, for DES in two-key EDE. */
232 MBEDTLS_KEY_LENGTH_DES_EDE = 128,
233 /** Key length in bits, including parity, for DES in three-key EDE. */
234 MBEDTLS_KEY_LENGTH_DES_EDE3 = 192,
235 };
236
237 /** Maximum length of any IV, in Bytes. */
238 /* This should ideally be derived automatically from list of ciphers.
239 * This should be kept in sync with MBEDTLS_SSL_MAX_IV_LENGTH defined
240 * in ssl_internal.h. */
241 #define MBEDTLS_MAX_IV_LENGTH 16
242
243 /** Maximum block size of any cipher, in Bytes. */
244 /* This should ideally be derived automatically from list of ciphers.
245 * This should be kept in sync with MBEDTLS_SSL_MAX_BLOCK_LENGTH defined
246 * in ssl_internal.h. */
247 #define MBEDTLS_MAX_BLOCK_LENGTH 16
248
249 /** Maximum key length, in Bytes. */
250 /* This should ideally be derived automatically from list of ciphers.
251 * For now, only check whether XTS is enabled which uses 64 Byte keys,
252 * and use 32 Bytes as an upper bound for the maximum key length otherwise.
253 * This should be kept in sync with MBEDTLS_SSL_MAX_BLOCK_LENGTH defined
254 * in ssl_internal.h, which however deliberately ignores the case of XTS
255 * since the latter isn't used in SSL/TLS. */
256 #if defined(MBEDTLS_CIPHER_MODE_XTS)
257 #define MBEDTLS_MAX_KEY_LENGTH 64
258 #else
259 #define MBEDTLS_MAX_KEY_LENGTH 32
260 #endif /* MBEDTLS_CIPHER_MODE_XTS */
261
262 /**
263 * Base cipher information (opaque struct).
264 */
265 typedef struct mbedtls_cipher_base_t mbedtls_cipher_base_t;
266
267 /**
268 * CMAC context (opaque struct).
269 */
270 typedef struct mbedtls_cmac_context_t mbedtls_cmac_context_t;
271
272 /**
273 * Cipher information. Allows calling cipher functions
274 * in a generic way.
275 */
276 typedef struct mbedtls_cipher_info_t
277 {
278 /** Full cipher identifier. For example,
279 * MBEDTLS_CIPHER_AES_256_CBC.
280 */
281 mbedtls_cipher_type_t type;
282
283 /** The cipher mode. For example, MBEDTLS_MODE_CBC. */
284 mbedtls_cipher_mode_t mode;
285
286 /** The cipher key length, in bits. This is the
287 * default length for variable sized ciphers.
288 * Includes parity bits for ciphers like DES.
289 */
290 unsigned int key_bitlen;
291
292 /** Name of the cipher. */
293 const char * name;
294
295 /** IV or nonce size, in Bytes.
296 * For ciphers that accept variable IV sizes,
297 * this is the recommended size.
298 */
299 unsigned int iv_size;
300
301 /** Bitflag comprised of MBEDTLS_CIPHER_VARIABLE_IV_LEN and
302 * MBEDTLS_CIPHER_VARIABLE_KEY_LEN indicating whether the
303 * cipher supports variable IV or variable key sizes, respectively.
304 */
305 int flags;
306
307 /** The block size, in Bytes. */
308 unsigned int block_size;
309
310 /** Struct for base cipher information and functions. */
311 const mbedtls_cipher_base_t *base;
312
313 } mbedtls_cipher_info_t;
314
315 /**
316 * Generic cipher context.
317 */
318 typedef struct mbedtls_cipher_context_t
319 {
320 /** Information about the associated cipher. */
321 const mbedtls_cipher_info_t *cipher_info;
322
323 /** Key length to use. */
324 int key_bitlen;
325
326 /** Operation that the key of the context has been
327 * initialized for.
328 */
329 mbedtls_operation_t operation;
330
331 #if defined(MBEDTLS_CIPHER_MODE_WITH_PADDING)
332 /** Padding functions to use, if relevant for
333 * the specific cipher mode.
334 */
335 void (*add_padding)( unsigned char *output, size_t olen, size_t data_len );
336 int (*get_padding)( unsigned char *input, size_t ilen, size_t *data_len );
337 #endif
338
339 /** Buffer for input that has not been processed yet. */
340 unsigned char unprocessed_data[MBEDTLS_MAX_BLOCK_LENGTH];
341
342 /** Number of Bytes that have not been processed yet. */
343 size_t unprocessed_len;
344
345 /** Current IV or NONCE_COUNTER for CTR-mode, data unit (or sector) number
346 * for XTS-mode. */
347 unsigned char iv[MBEDTLS_MAX_IV_LENGTH];
348
349 /** IV size in Bytes, for ciphers with variable-length IVs. */
350 size_t iv_size;
351
352 /** The cipher-specific context. */
353 void *cipher_ctx;
354
355 #if defined(MBEDTLS_CMAC_C)
356 /** CMAC-specific context. */
357 mbedtls_cmac_context_t *cmac_ctx;
358 #endif
359
360 #if defined(MBEDTLS_USE_PSA_CRYPTO)
361 /** Indicates whether the cipher operations should be performed
362 * by Mbed TLS' own crypto library or an external implementation
363 * of the PSA Crypto API.
364 * This is unset if the cipher context was established through
365 * mbedtls_cipher_setup(), and set if it was established through
366 * mbedtls_cipher_setup_psa().
367 */
368 unsigned char psa_enabled;
369 #endif /* MBEDTLS_USE_PSA_CRYPTO */
370
371 } mbedtls_cipher_context_t;
372
373 /**
374 * \brief This function retrieves the list of ciphers supported
375 * by the generic cipher module.
376 *
377 * For any cipher identifier in the returned list, you can
378 * obtain the corresponding generic cipher information structure
379 * via mbedtls_cipher_info_from_type(), which can then be used
380 * to prepare a cipher context via mbedtls_cipher_setup().
381 *
382 *
383 * \return A statically-allocated array of cipher identifiers
384 * of type cipher_type_t. The last entry is zero.
385 */
386 const int *mbedtls_cipher_list( void );
387
388 /**
389 * \brief This function retrieves the cipher-information
390 * structure associated with the given cipher name.
391 *
392 * \param cipher_name Name of the cipher to search for. This must not be
393 * \c NULL.
394 *
395 * \return The cipher information structure associated with the
396 * given \p cipher_name.
397 * \return \c NULL if the associated cipher information is not found.
398 */
399 const mbedtls_cipher_info_t *mbedtls_cipher_info_from_string( const char *cipher_name );
400
401 /**
402 * \brief This function retrieves the cipher-information
403 * structure associated with the given cipher type.
404 *
405 * \param cipher_type Type of the cipher to search for.
406 *
407 * \return The cipher information structure associated with the
408 * given \p cipher_type.
409 * \return \c NULL if the associated cipher information is not found.
410 */
411 const mbedtls_cipher_info_t *mbedtls_cipher_info_from_type( const mbedtls_cipher_type_t cipher_type );
412
413 /**
414 * \brief This function retrieves the cipher-information
415 * structure associated with the given cipher ID,
416 * key size and mode.
417 *
418 * \param cipher_id The ID of the cipher to search for. For example,
419 * #MBEDTLS_CIPHER_ID_AES.
420 * \param key_bitlen The length of the key in bits.
421 * \param mode The cipher mode. For example, #MBEDTLS_MODE_CBC.
422 *
423 * \return The cipher information structure associated with the
424 * given \p cipher_id.
425 * \return \c NULL if the associated cipher information is not found.
426 */
427 const mbedtls_cipher_info_t *mbedtls_cipher_info_from_values( const mbedtls_cipher_id_t cipher_id,
428 int key_bitlen,
429 const mbedtls_cipher_mode_t mode );
430
431 /**
432 * \brief This function initializes a \p cipher_context as NONE.
433 *
434 * \param ctx The context to be initialized. This must not be \c NULL.
435 */
436 void mbedtls_cipher_init( mbedtls_cipher_context_t *ctx );
437
438 /**
439 * \brief This function frees and clears the cipher-specific
440 * context of \p ctx. Freeing \p ctx itself remains the
441 * responsibility of the caller.
442 *
443 * \param ctx The context to be freed. If this is \c NULL, the
444 * function has no effect, otherwise this must point to an
445 * initialized context.
446 */
447 void mbedtls_cipher_free( mbedtls_cipher_context_t *ctx );
448
449
450 /**
451 * \brief This function initializes a cipher context for
452 * use with the given cipher primitive.
453 *
454 * \param ctx The context to initialize. This must be initialized.
455 * \param cipher_info The cipher to use.
456 *
457 * \return \c 0 on success.
458 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
459 * parameter-verification failure.
460 * \return #MBEDTLS_ERR_CIPHER_ALLOC_FAILED if allocation of the
461 * cipher-specific context fails.
462 *
463 * \internal Currently, the function also clears the structure.
464 * In future versions, the caller will be required to call
465 * mbedtls_cipher_init() on the structure first.
466 */
467 int mbedtls_cipher_setup( mbedtls_cipher_context_t *ctx,
468 const mbedtls_cipher_info_t *cipher_info );
469
470 #if defined(MBEDTLS_USE_PSA_CRYPTO)
471 /**
472 * \brief This function initializes a cipher context for
473 * PSA-based use with the given cipher primitive.
474 *
475 * \note See #MBEDTLS_USE_PSA_CRYPTO for information on PSA.
476 *
477 * \param ctx The context to initialize. May not be \c NULL.
478 * \param cipher_info The cipher to use.
479 * \param taglen For AEAD ciphers, the length in bytes of the
480 * authentication tag to use. Subsequent uses of
481 * mbedtls_cipher_auth_encrypt() or
482 * mbedtls_cipher_auth_decrypt() must provide
483 * the same tag length.
484 * For non-AEAD ciphers, the value must be \c 0.
485 *
486 * \return \c 0 on success.
487 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
488 * parameter-verification failure.
489 * \return #MBEDTLS_ERR_CIPHER_ALLOC_FAILED if allocation of the
490 * cipher-specific context fails.
491 */
492 int mbedtls_cipher_setup_psa( mbedtls_cipher_context_t *ctx,
493 const mbedtls_cipher_info_t *cipher_info,
494 size_t taglen );
495 #endif /* MBEDTLS_USE_PSA_CRYPTO */
496
497 /**
498 * \brief This function returns the block size of the given cipher.
499 *
500 * \param ctx The context of the cipher. This must be initialized.
501 *
502 * \return The block size of the underlying cipher.
503 * \return \c 0 if \p ctx has not been initialized.
504 */
mbedtls_cipher_get_block_size(const mbedtls_cipher_context_t * ctx)505 static inline unsigned int mbedtls_cipher_get_block_size(
506 const mbedtls_cipher_context_t *ctx )
507 {
508 MBEDTLS_INTERNAL_VALIDATE_RET( ctx != NULL, 0 );
509 if( ctx->cipher_info == NULL )
510 return 0;
511
512 return ctx->cipher_info->block_size;
513 }
514
515 /**
516 * \brief This function returns the mode of operation for
517 * the cipher. For example, MBEDTLS_MODE_CBC.
518 *
519 * \param ctx The context of the cipher. This must be initialized.
520 *
521 * \return The mode of operation.
522 * \return #MBEDTLS_MODE_NONE if \p ctx has not been initialized.
523 */
mbedtls_cipher_get_cipher_mode(const mbedtls_cipher_context_t * ctx)524 static inline mbedtls_cipher_mode_t mbedtls_cipher_get_cipher_mode(
525 const mbedtls_cipher_context_t *ctx )
526 {
527 MBEDTLS_INTERNAL_VALIDATE_RET( ctx != NULL, MBEDTLS_MODE_NONE );
528 if( ctx->cipher_info == NULL )
529 return MBEDTLS_MODE_NONE;
530
531 return ctx->cipher_info->mode;
532 }
533
534 /**
535 * \brief This function returns the size of the IV or nonce
536 * of the cipher, in Bytes.
537 *
538 * \param ctx The context of the cipher. This must be initialized.
539 *
540 * \return The recommended IV size if no IV has been set.
541 * \return \c 0 for ciphers not using an IV or a nonce.
542 * \return The actual size if an IV has been set.
543 */
mbedtls_cipher_get_iv_size(const mbedtls_cipher_context_t * ctx)544 static inline int mbedtls_cipher_get_iv_size(
545 const mbedtls_cipher_context_t *ctx )
546 {
547 MBEDTLS_INTERNAL_VALIDATE_RET( ctx != NULL, 0 );
548 if( ctx->cipher_info == NULL )
549 return 0;
550
551 if( ctx->iv_size != 0 )
552 return (int) ctx->iv_size;
553
554 return (int) ctx->cipher_info->iv_size;
555 }
556
557 /**
558 * \brief This function returns the type of the given cipher.
559 *
560 * \param ctx The context of the cipher. This must be initialized.
561 *
562 * \return The type of the cipher.
563 * \return #MBEDTLS_CIPHER_NONE if \p ctx has not been initialized.
564 */
mbedtls_cipher_get_type(const mbedtls_cipher_context_t * ctx)565 static inline mbedtls_cipher_type_t mbedtls_cipher_get_type(
566 const mbedtls_cipher_context_t *ctx )
567 {
568 MBEDTLS_INTERNAL_VALIDATE_RET(
569 ctx != NULL, MBEDTLS_CIPHER_NONE );
570 if( ctx->cipher_info == NULL )
571 return MBEDTLS_CIPHER_NONE;
572
573 return ctx->cipher_info->type;
574 }
575
576 /**
577 * \brief This function returns the name of the given cipher
578 * as a string.
579 *
580 * \param ctx The context of the cipher. This must be initialized.
581 *
582 * \return The name of the cipher.
583 * \return NULL if \p ctx has not been not initialized.
584 */
mbedtls_cipher_get_name(const mbedtls_cipher_context_t * ctx)585 static inline const char *mbedtls_cipher_get_name(
586 const mbedtls_cipher_context_t *ctx )
587 {
588 MBEDTLS_INTERNAL_VALIDATE_RET( ctx != NULL, 0 );
589 if( ctx->cipher_info == NULL )
590 return 0;
591
592 return ctx->cipher_info->name;
593 }
594
595 /**
596 * \brief This function returns the key length of the cipher.
597 *
598 * \param ctx The context of the cipher. This must be initialized.
599 *
600 * \return The key length of the cipher in bits.
601 * \return #MBEDTLS_KEY_LENGTH_NONE if ctx \p has not been
602 * initialized.
603 */
mbedtls_cipher_get_key_bitlen(const mbedtls_cipher_context_t * ctx)604 static inline int mbedtls_cipher_get_key_bitlen(
605 const mbedtls_cipher_context_t *ctx )
606 {
607 MBEDTLS_INTERNAL_VALIDATE_RET(
608 ctx != NULL, MBEDTLS_KEY_LENGTH_NONE );
609 if( ctx->cipher_info == NULL )
610 return MBEDTLS_KEY_LENGTH_NONE;
611
612 return (int) ctx->cipher_info->key_bitlen;
613 }
614
615 /**
616 * \brief This function returns the operation of the given cipher.
617 *
618 * \param ctx The context of the cipher. This must be initialized.
619 *
620 * \return The type of operation: #MBEDTLS_ENCRYPT or #MBEDTLS_DECRYPT.
621 * \return #MBEDTLS_OPERATION_NONE if \p ctx has not been initialized.
622 */
mbedtls_cipher_get_operation(const mbedtls_cipher_context_t * ctx)623 static inline mbedtls_operation_t mbedtls_cipher_get_operation(
624 const mbedtls_cipher_context_t *ctx )
625 {
626 MBEDTLS_INTERNAL_VALIDATE_RET(
627 ctx != NULL, MBEDTLS_OPERATION_NONE );
628 if( ctx->cipher_info == NULL )
629 return MBEDTLS_OPERATION_NONE;
630
631 return ctx->operation;
632 }
633
634 /**
635 * \brief This function sets the key to use with the given context.
636 *
637 * \param ctx The generic cipher context. This must be initialized and
638 * bound to a cipher information structure.
639 * \param key The key to use. This must be a readable buffer of at
640 * least \p key_bitlen Bits.
641 * \param key_bitlen The key length to use, in Bits.
642 * \param operation The operation that the key will be used for:
643 * #MBEDTLS_ENCRYPT or #MBEDTLS_DECRYPT.
644 *
645 * \return \c 0 on success.
646 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
647 * parameter-verification failure.
648 * \return A cipher-specific error code on failure.
649 */
650 int mbedtls_cipher_setkey( mbedtls_cipher_context_t *ctx,
651 const unsigned char *key,
652 int key_bitlen,
653 const mbedtls_operation_t operation );
654
655 #if defined(MBEDTLS_CIPHER_MODE_WITH_PADDING)
656 /**
657 * \brief This function sets the padding mode, for cipher modes
658 * that use padding.
659 *
660 * The default passing mode is PKCS7 padding.
661 *
662 * \param ctx The generic cipher context. This must be initialized and
663 * bound to a cipher information structure.
664 * \param mode The padding mode.
665 *
666 * \return \c 0 on success.
667 * \return #MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE
668 * if the selected padding mode is not supported.
669 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA if the cipher mode
670 * does not support padding.
671 */
672 int mbedtls_cipher_set_padding_mode( mbedtls_cipher_context_t *ctx,
673 mbedtls_cipher_padding_t mode );
674 #endif /* MBEDTLS_CIPHER_MODE_WITH_PADDING */
675
676 /**
677 * \brief This function sets the initialization vector (IV)
678 * or nonce.
679 *
680 * \note Some ciphers do not use IVs nor nonce. For these
681 * ciphers, this function has no effect.
682 *
683 * \param ctx The generic cipher context. This must be initialized and
684 * bound to a cipher information structure.
685 * \param iv The IV to use, or NONCE_COUNTER for CTR-mode ciphers. This
686 * must be a readable buffer of at least \p iv_len Bytes.
687 * \param iv_len The IV length for ciphers with variable-size IV.
688 * This parameter is discarded by ciphers with fixed-size IV.
689 *
690 * \return \c 0 on success.
691 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
692 * parameter-verification failure.
693 */
694 int mbedtls_cipher_set_iv( mbedtls_cipher_context_t *ctx,
695 const unsigned char *iv,
696 size_t iv_len );
697
698 /**
699 * \brief This function resets the cipher state.
700 *
701 * \param ctx The generic cipher context. This must be initialized.
702 *
703 * \return \c 0 on success.
704 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
705 * parameter-verification failure.
706 */
707 int mbedtls_cipher_reset( mbedtls_cipher_context_t *ctx );
708
709 #if defined(MBEDTLS_GCM_C) || defined(MBEDTLS_CHACHAPOLY_C)
710 /**
711 * \brief This function adds additional data for AEAD ciphers.
712 * Currently supported with GCM and ChaCha20+Poly1305.
713 * This must be called exactly once, after
714 * mbedtls_cipher_reset().
715 *
716 * \param ctx The generic cipher context. This must be initialized.
717 * \param ad The additional data to use. This must be a readable
718 * buffer of at least \p ad_len Bytes.
719 * \param ad_len The length of \p ad in Bytes.
720 *
721 * \return \c 0 on success.
722 * \return A specific error code on failure.
723 */
724 int mbedtls_cipher_update_ad( mbedtls_cipher_context_t *ctx,
725 const unsigned char *ad, size_t ad_len );
726 #endif /* MBEDTLS_GCM_C || MBEDTLS_CHACHAPOLY_C */
727
728 /**
729 * \brief The generic cipher update function. It encrypts or
730 * decrypts using the given cipher context. Writes as
731 * many block-sized blocks of data as possible to output.
732 * Any data that cannot be written immediately is either
733 * added to the next block, or flushed when
734 * mbedtls_cipher_finish() is called.
735 * Exception: For MBEDTLS_MODE_ECB, expects a single block
736 * in size. For example, 16 Bytes for AES.
737 *
738 * \note If the underlying cipher is used in GCM mode, all calls
739 * to this function, except for the last one before
740 * mbedtls_cipher_finish(), must have \p ilen as a
741 * multiple of the block size of the cipher.
742 *
743 * \param ctx The generic cipher context. This must be initialized and
744 * bound to a key.
745 * \param input The buffer holding the input data. This must be a
746 * readable buffer of at least \p ilen Bytes.
747 * \param ilen The length of the input data.
748 * \param output The buffer for the output data. This must be able to
749 * hold at least `ilen + block_size`. This must not be the
750 * same buffer as \p input.
751 * \param olen The length of the output data, to be updated with the
752 * actual number of Bytes written. This must not be
753 * \c NULL.
754 *
755 * \return \c 0 on success.
756 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
757 * parameter-verification failure.
758 * \return #MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE on an
759 * unsupported mode for a cipher.
760 * \return A cipher-specific error code on failure.
761 */
762 int mbedtls_cipher_update( mbedtls_cipher_context_t *ctx,
763 const unsigned char *input,
764 size_t ilen, unsigned char *output,
765 size_t *olen );
766
767 /**
768 * \brief The generic cipher finalization function. If data still
769 * needs to be flushed from an incomplete block, the data
770 * contained in it is padded to the size of
771 * the last block, and written to the \p output buffer.
772 *
773 * \param ctx The generic cipher context. This must be initialized and
774 * bound to a key.
775 * \param output The buffer to write data to. This needs to be a writable
776 * buffer of at least \p block_size Bytes.
777 * \param olen The length of the data written to the \p output buffer.
778 * This may not be \c NULL.
779 *
780 * \return \c 0 on success.
781 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
782 * parameter-verification failure.
783 * \return #MBEDTLS_ERR_CIPHER_FULL_BLOCK_EXPECTED on decryption
784 * expecting a full block but not receiving one.
785 * \return #MBEDTLS_ERR_CIPHER_INVALID_PADDING on invalid padding
786 * while decrypting.
787 * \return A cipher-specific error code on failure.
788 */
789 int mbedtls_cipher_finish( mbedtls_cipher_context_t *ctx,
790 unsigned char *output, size_t *olen );
791
792 #if defined(MBEDTLS_GCM_C) || defined(MBEDTLS_CHACHAPOLY_C)
793 /**
794 * \brief This function writes a tag for AEAD ciphers.
795 * Currently supported with GCM and ChaCha20+Poly1305.
796 * This must be called after mbedtls_cipher_finish().
797 *
798 * \param ctx The generic cipher context. This must be initialized,
799 * bound to a key, and have just completed a cipher
800 * operation through mbedtls_cipher_finish() the tag for
801 * which should be written.
802 * \param tag The buffer to write the tag to. This must be a writable
803 * buffer of at least \p tag_len Bytes.
804 * \param tag_len The length of the tag to write.
805 *
806 * \return \c 0 on success.
807 * \return A specific error code on failure.
808 */
809 int mbedtls_cipher_write_tag( mbedtls_cipher_context_t *ctx,
810 unsigned char *tag, size_t tag_len );
811
812 /**
813 * \brief This function checks the tag for AEAD ciphers.
814 * Currently supported with GCM and ChaCha20+Poly1305.
815 * This must be called after mbedtls_cipher_finish().
816 *
817 * \param ctx The generic cipher context. This must be initialized.
818 * \param tag The buffer holding the tag. This must be a readable
819 * buffer of at least \p tag_len Bytes.
820 * \param tag_len The length of the tag to check.
821 *
822 * \return \c 0 on success.
823 * \return A specific error code on failure.
824 */
825 int mbedtls_cipher_check_tag( mbedtls_cipher_context_t *ctx,
826 const unsigned char *tag, size_t tag_len );
827 #endif /* MBEDTLS_GCM_C || MBEDTLS_CHACHAPOLY_C */
828
829 /**
830 * \brief The generic all-in-one encryption/decryption function,
831 * for all ciphers except AEAD constructs.
832 *
833 * \param ctx The generic cipher context. This must be initialized.
834 * \param iv The IV to use, or NONCE_COUNTER for CTR-mode ciphers.
835 * This must be a readable buffer of at least \p iv_len
836 * Bytes.
837 * \param iv_len The IV length for ciphers with variable-size IV.
838 * This parameter is discarded by ciphers with fixed-size
839 * IV.
840 * \param input The buffer holding the input data. This must be a
841 * readable buffer of at least \p ilen Bytes.
842 * \param ilen The length of the input data in Bytes.
843 * \param output The buffer for the output data. This must be able to
844 * hold at least `ilen + block_size`. This must not be the
845 * same buffer as \p input.
846 * \param olen The length of the output data, to be updated with the
847 * actual number of Bytes written. This must not be
848 * \c NULL.
849 *
850 * \note Some ciphers do not use IVs nor nonce. For these
851 * ciphers, use \p iv = NULL and \p iv_len = 0.
852 *
853 * \return \c 0 on success.
854 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
855 * parameter-verification failure.
856 * \return #MBEDTLS_ERR_CIPHER_FULL_BLOCK_EXPECTED on decryption
857 * expecting a full block but not receiving one.
858 * \return #MBEDTLS_ERR_CIPHER_INVALID_PADDING on invalid padding
859 * while decrypting.
860 * \return A cipher-specific error code on failure.
861 */
862 int mbedtls_cipher_crypt( mbedtls_cipher_context_t *ctx,
863 const unsigned char *iv, size_t iv_len,
864 const unsigned char *input, size_t ilen,
865 unsigned char *output, size_t *olen );
866
867 #if defined(MBEDTLS_CIPHER_MODE_AEAD)
868 #if ! defined(MBEDTLS_DEPRECATED_REMOVED)
869 #if defined(MBEDTLS_DEPRECATED_WARNING)
870 #define MBEDTLS_DEPRECATED __attribute__((deprecated))
871 #else
872 #define MBEDTLS_DEPRECATED
873 #endif /* MBEDTLS_DEPRECATED_WARNING */
874 /**
875 * \brief The generic authenticated encryption (AEAD) function.
876 *
877 * \deprecated Superseded by mbedtls_cipher_auth_encrypt_ext().
878 *
879 * \note This function only supports AEAD algorithms, not key
880 * wrapping algorithms such as NIST_KW; for this, see
881 * mbedtls_cipher_auth_encrypt_ext().
882 *
883 * \param ctx The generic cipher context. This must be initialized and
884 * bound to a key associated with an AEAD algorithm.
885 * \param iv The nonce to use. This must be a readable buffer of
886 * at least \p iv_len Bytes and must not be \c NULL.
887 * \param iv_len The length of the nonce. This must satisfy the
888 * constraints imposed by the AEAD cipher used.
889 * \param ad The additional data to authenticate. This must be a
890 * readable buffer of at least \p ad_len Bytes, and may
891 * be \c NULL is \p ad_len is \c 0.
892 * \param ad_len The length of \p ad.
893 * \param input The buffer holding the input data. This must be a
894 * readable buffer of at least \p ilen Bytes, and may be
895 * \c NULL if \p ilen is \c 0.
896 * \param ilen The length of the input data.
897 * \param output The buffer for the output data. This must be a
898 * writable buffer of at least \p ilen Bytes, and must
899 * not be \c NULL.
900 * \param olen This will be filled with the actual number of Bytes
901 * written to the \p output buffer. This must point to a
902 * writable object of type \c size_t.
903 * \param tag The buffer for the authentication tag. This must be a
904 * writable buffer of at least \p tag_len Bytes. See note
905 * below regarding restrictions with PSA-based contexts.
906 * \param tag_len The desired length of the authentication tag. This
907 * must match the constraints imposed by the AEAD cipher
908 * used, and in particular must not be \c 0.
909 *
910 * \note If the context is based on PSA (that is, it was set up
911 * with mbedtls_cipher_setup_psa()), then it is required
912 * that \c tag == output + ilen. That is, the tag must be
913 * appended to the ciphertext as recommended by RFC 5116.
914 *
915 * \return \c 0 on success.
916 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
917 * parameter-verification failure.
918 * \return A cipher-specific error code on failure.
919 */
920 int mbedtls_cipher_auth_encrypt( mbedtls_cipher_context_t *ctx,
921 const unsigned char *iv, size_t iv_len,
922 const unsigned char *ad, size_t ad_len,
923 const unsigned char *input, size_t ilen,
924 unsigned char *output, size_t *olen,
925 unsigned char *tag, size_t tag_len )
926 MBEDTLS_DEPRECATED;
927
928 /**
929 * \brief The generic authenticated decryption (AEAD) function.
930 *
931 * \deprecated Superseded by mbedtls_cipher_auth_decrypt_ext().
932 *
933 * \note This function only supports AEAD algorithms, not key
934 * wrapping algorithms such as NIST_KW; for this, see
935 * mbedtls_cipher_auth_decrypt_ext().
936 *
937 * \note If the data is not authentic, then the output buffer
938 * is zeroed out to prevent the unauthentic plaintext being
939 * used, making this interface safer.
940 *
941 * \param ctx The generic cipher context. This must be initialized and
942 * bound to a key associated with an AEAD algorithm.
943 * \param iv The nonce to use. This must be a readable buffer of
944 * at least \p iv_len Bytes and must not be \c NULL.
945 * \param iv_len The length of the nonce. This must satisfy the
946 * constraints imposed by the AEAD cipher used.
947 * \param ad The additional data to authenticate. This must be a
948 * readable buffer of at least \p ad_len Bytes, and may
949 * be \c NULL is \p ad_len is \c 0.
950 * \param ad_len The length of \p ad.
951 * \param input The buffer holding the input data. This must be a
952 * readable buffer of at least \p ilen Bytes, and may be
953 * \c NULL if \p ilen is \c 0.
954 * \param ilen The length of the input data.
955 * \param output The buffer for the output data. This must be a
956 * writable buffer of at least \p ilen Bytes, and must
957 * not be \c NULL.
958 * \param olen This will be filled with the actual number of Bytes
959 * written to the \p output buffer. This must point to a
960 * writable object of type \c size_t.
961 * \param tag The buffer for the authentication tag. This must be a
962 * readable buffer of at least \p tag_len Bytes. See note
963 * below regarding restrictions with PSA-based contexts.
964 * \param tag_len The length of the authentication tag. This must match
965 * the constraints imposed by the AEAD cipher used, and in
966 * particular must not be \c 0.
967 *
968 * \note If the context is based on PSA (that is, it was set up
969 * with mbedtls_cipher_setup_psa()), then it is required
970 * that \c tag == input + len. That is, the tag must be
971 * appended to the ciphertext as recommended by RFC 5116.
972 *
973 * \return \c 0 on success.
974 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
975 * parameter-verification failure.
976 * \return #MBEDTLS_ERR_CIPHER_AUTH_FAILED if data is not authentic.
977 * \return A cipher-specific error code on failure.
978 */
979 int mbedtls_cipher_auth_decrypt( mbedtls_cipher_context_t *ctx,
980 const unsigned char *iv, size_t iv_len,
981 const unsigned char *ad, size_t ad_len,
982 const unsigned char *input, size_t ilen,
983 unsigned char *output, size_t *olen,
984 const unsigned char *tag, size_t tag_len )
985 MBEDTLS_DEPRECATED;
986 #undef MBEDTLS_DEPRECATED
987 #endif /* MBEDTLS_DEPRECATED_REMOVED */
988 #endif /* MBEDTLS_CIPHER_MODE_AEAD */
989
990 #if defined(MBEDTLS_CIPHER_MODE_AEAD) || defined(MBEDTLS_NIST_KW_C)
991 /**
992 * \brief The authenticated encryption (AEAD/NIST_KW) function.
993 *
994 * \note For AEAD modes, the tag will be appended to the
995 * ciphertext, as recommended by RFC 5116.
996 * (NIST_KW doesn't have a separate tag.)
997 *
998 * \param ctx The generic cipher context. This must be initialized and
999 * bound to a key, with an AEAD algorithm or NIST_KW.
1000 * \param iv The nonce to use. This must be a readable buffer of
1001 * at least \p iv_len Bytes and may be \c NULL if \p
1002 * iv_len is \c 0.
1003 * \param iv_len The length of the nonce. For AEAD ciphers, this must
1004 * satisfy the constraints imposed by the cipher used.
1005 * For NIST_KW, this must be \c 0.
1006 * \param ad The additional data to authenticate. This must be a
1007 * readable buffer of at least \p ad_len Bytes, and may
1008 * be \c NULL is \p ad_len is \c 0.
1009 * \param ad_len The length of \p ad. For NIST_KW, this must be \c 0.
1010 * \param input The buffer holding the input data. This must be a
1011 * readable buffer of at least \p ilen Bytes, and may be
1012 * \c NULL if \p ilen is \c 0.
1013 * \param ilen The length of the input data.
1014 * \param output The buffer for the output data. This must be a
1015 * writable buffer of at least \p output_len Bytes, and
1016 * must not be \c NULL.
1017 * \param output_len The length of the \p output buffer in Bytes. For AEAD
1018 * ciphers, this must be at least \p ilen + \p tag_len.
1019 * For NIST_KW, this must be at least \p ilen + 8
1020 * (rounded up to a multiple of 8 if KWP is used);
1021 * \p ilen + 15 is always a safe value.
1022 * \param olen This will be filled with the actual number of Bytes
1023 * written to the \p output buffer. This must point to a
1024 * writable object of type \c size_t.
1025 * \param tag_len The desired length of the authentication tag. For AEAD
1026 * ciphers, this must match the constraints imposed by
1027 * the cipher used, and in particular must not be \c 0.
1028 * For NIST_KW, this must be \c 0.
1029 *
1030 * \return \c 0 on success.
1031 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
1032 * parameter-verification failure.
1033 * \return A cipher-specific error code on failure.
1034 */
1035 int mbedtls_cipher_auth_encrypt_ext( mbedtls_cipher_context_t *ctx,
1036 const unsigned char *iv, size_t iv_len,
1037 const unsigned char *ad, size_t ad_len,
1038 const unsigned char *input, size_t ilen,
1039 unsigned char *output, size_t output_len,
1040 size_t *olen, size_t tag_len );
1041
1042 /**
1043 * \brief The authenticated encryption (AEAD/NIST_KW) function.
1044 *
1045 * \note If the data is not authentic, then the output buffer
1046 * is zeroed out to prevent the unauthentic plaintext being
1047 * used, making this interface safer.
1048 *
1049 * \note For AEAD modes, the tag must be appended to the
1050 * ciphertext, as recommended by RFC 5116.
1051 * (NIST_KW doesn't have a separate tag.)
1052 *
1053 * \param ctx The generic cipher context. This must be initialized and
1054 * bound to a key, with an AEAD algorithm or NIST_KW.
1055 * \param iv The nonce to use. This must be a readable buffer of
1056 * at least \p iv_len Bytes and may be \c NULL if \p
1057 * iv_len is \c 0.
1058 * \param iv_len The length of the nonce. For AEAD ciphers, this must
1059 * satisfy the constraints imposed by the cipher used.
1060 * For NIST_KW, this must be \c 0.
1061 * \param ad The additional data to authenticate. This must be a
1062 * readable buffer of at least \p ad_len Bytes, and may
1063 * be \c NULL is \p ad_len is \c 0.
1064 * \param ad_len The length of \p ad. For NIST_KW, this must be \c 0.
1065 * \param input The buffer holding the input data. This must be a
1066 * readable buffer of at least \p ilen Bytes, and may be
1067 * \c NULL if \p ilen is \c 0.
1068 * \param ilen The length of the input data. For AEAD ciphers this
1069 * must be at least \p tag_len. For NIST_KW this must be
1070 * at least \c 8.
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 * may be \c NULL if \p output_len is \c 0.
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 * \param olen This will be filled with the actual number of Bytes
1078 * written to the \p output buffer. This must point to a
1079 * writable object of type \c size_t.
1080 * \param tag_len The actual length of the authentication tag. For AEAD
1081 * ciphers, this must match the constraints imposed by
1082 * the cipher used, and in particular must not be \c 0.
1083 * For NIST_KW, this must be \c 0.
1084 *
1085 * \return \c 0 on success.
1086 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
1087 * parameter-verification failure.
1088 * \return #MBEDTLS_ERR_CIPHER_AUTH_FAILED if data is not authentic.
1089 * \return A cipher-specific error code on failure.
1090 */
1091 int mbedtls_cipher_auth_decrypt_ext( mbedtls_cipher_context_t *ctx,
1092 const unsigned char *iv, size_t iv_len,
1093 const unsigned char *ad, size_t ad_len,
1094 const unsigned char *input, size_t ilen,
1095 unsigned char *output, size_t output_len,
1096 size_t *olen, size_t tag_len );
1097 #endif /* MBEDTLS_CIPHER_MODE_AEAD || MBEDTLS_NIST_KW_C */
1098 #ifdef __cplusplus
1099 }
1100 #endif
1101
1102 #endif /* MBEDTLS_CIPHER_H */
1103
