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 #define MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE -0x6080 /**< The selected feature is not available. */
58 #define MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA -0x6100 /**< Bad input parameters. */
59 #define MBEDTLS_ERR_CIPHER_ALLOC_FAILED -0x6180 /**< Failed to allocate memory. */
60 #define MBEDTLS_ERR_CIPHER_INVALID_PADDING -0x6200 /**< Input data contains invalid padding and is rejected. */
61 #define MBEDTLS_ERR_CIPHER_FULL_BLOCK_EXPECTED -0x6280 /**< Decryption of block requires a full block. */
62 #define MBEDTLS_ERR_CIPHER_AUTH_FAILED -0x6300 /**< Authentication failed (for AEAD modes). */
63 #define MBEDTLS_ERR_CIPHER_INVALID_CONTEXT -0x6380 /**< The context is invalid. For example, because it was freed. */
64
65 /* MBEDTLS_ERR_CIPHER_HW_ACCEL_FAILED is deprecated and should not be used. */
66 #define MBEDTLS_ERR_CIPHER_HW_ACCEL_FAILED -0x6400 /**< Cipher hardware accelerator failed. */
67
68 #define MBEDTLS_CIPHER_VARIABLE_IV_LEN 0x01 /**< Cipher accepts IVs of variable length. */
69 #define MBEDTLS_CIPHER_VARIABLE_KEY_LEN 0x02 /**< Cipher accepts keys of variable length. */
70
71 #ifdef __cplusplus
72 extern "C" {
73 #endif
74
75 /**
76 * \brief Supported cipher types.
77 *
78 * \warning RC4 and DES are considered weak ciphers and their use
79 * constitutes a security risk. Arm recommends considering stronger
80 * ciphers instead.
81 */
82 typedef enum {
83 MBEDTLS_CIPHER_ID_NONE = 0, /**< Placeholder to mark the end of cipher ID lists. */
84 MBEDTLS_CIPHER_ID_NULL, /**< The identity cipher, treated as a stream cipher. */
85 MBEDTLS_CIPHER_ID_AES, /**< The AES cipher. */
86 MBEDTLS_CIPHER_ID_DES, /**< The DES cipher. */
87 MBEDTLS_CIPHER_ID_3DES, /**< The Triple DES cipher. */
88 MBEDTLS_CIPHER_ID_CAMELLIA, /**< The Camellia cipher. */
89 MBEDTLS_CIPHER_ID_BLOWFISH, /**< The Blowfish cipher. */
90 MBEDTLS_CIPHER_ID_ARC4, /**< The RC4 cipher. */
91 MBEDTLS_CIPHER_ID_ARIA, /**< The Aria cipher. */
92 MBEDTLS_CIPHER_ID_CHACHA20, /**< The ChaCha20 cipher. */
93 } mbedtls_cipher_id_t;
94
95 /**
96 * \brief Supported {cipher type, cipher mode} pairs.
97 *
98 * \warning RC4 and DES are considered weak ciphers and their use
99 * constitutes a security risk. Arm recommends considering stronger
100 * ciphers instead.
101 */
102 typedef enum {
103 MBEDTLS_CIPHER_NONE = 0, /**< Placeholder to mark the end of cipher-pair lists. */
104 MBEDTLS_CIPHER_NULL, /**< The identity stream cipher. */
105 MBEDTLS_CIPHER_AES_128_ECB, /**< AES cipher with 128-bit ECB mode. */
106 MBEDTLS_CIPHER_AES_192_ECB, /**< AES cipher with 192-bit ECB mode. */
107 MBEDTLS_CIPHER_AES_256_ECB, /**< AES cipher with 256-bit ECB mode. */
108 MBEDTLS_CIPHER_AES_128_CBC, /**< AES cipher with 128-bit CBC mode. */
109 MBEDTLS_CIPHER_AES_192_CBC, /**< AES cipher with 192-bit CBC mode. */
110 MBEDTLS_CIPHER_AES_256_CBC, /**< AES cipher with 256-bit CBC mode. */
111 MBEDTLS_CIPHER_AES_128_CFB128, /**< AES cipher with 128-bit CFB128 mode. */
112 MBEDTLS_CIPHER_AES_192_CFB128, /**< AES cipher with 192-bit CFB128 mode. */
113 MBEDTLS_CIPHER_AES_256_CFB128, /**< AES cipher with 256-bit CFB128 mode. */
114 MBEDTLS_CIPHER_AES_128_CTR, /**< AES cipher with 128-bit CTR mode. */
115 MBEDTLS_CIPHER_AES_192_CTR, /**< AES cipher with 192-bit CTR mode. */
116 MBEDTLS_CIPHER_AES_256_CTR, /**< AES cipher with 256-bit CTR mode. */
117 MBEDTLS_CIPHER_AES_128_GCM, /**< AES cipher with 128-bit GCM mode. */
118 MBEDTLS_CIPHER_AES_192_GCM, /**< AES cipher with 192-bit GCM mode. */
119 MBEDTLS_CIPHER_AES_256_GCM, /**< AES cipher with 256-bit GCM mode. */
120 MBEDTLS_CIPHER_CAMELLIA_128_ECB, /**< Camellia cipher with 128-bit ECB mode. */
121 MBEDTLS_CIPHER_CAMELLIA_192_ECB, /**< Camellia cipher with 192-bit ECB mode. */
122 MBEDTLS_CIPHER_CAMELLIA_256_ECB, /**< Camellia cipher with 256-bit ECB mode. */
123 MBEDTLS_CIPHER_CAMELLIA_128_CBC, /**< Camellia cipher with 128-bit CBC mode. */
124 MBEDTLS_CIPHER_CAMELLIA_192_CBC, /**< Camellia cipher with 192-bit CBC mode. */
125 MBEDTLS_CIPHER_CAMELLIA_256_CBC, /**< Camellia cipher with 256-bit CBC mode. */
126 MBEDTLS_CIPHER_CAMELLIA_128_CFB128, /**< Camellia cipher with 128-bit CFB128 mode. */
127 MBEDTLS_CIPHER_CAMELLIA_192_CFB128, /**< Camellia cipher with 192-bit CFB128 mode. */
128 MBEDTLS_CIPHER_CAMELLIA_256_CFB128, /**< Camellia cipher with 256-bit CFB128 mode. */
129 MBEDTLS_CIPHER_CAMELLIA_128_CTR, /**< Camellia cipher with 128-bit CTR mode. */
130 MBEDTLS_CIPHER_CAMELLIA_192_CTR, /**< Camellia cipher with 192-bit CTR mode. */
131 MBEDTLS_CIPHER_CAMELLIA_256_CTR, /**< Camellia cipher with 256-bit CTR mode. */
132 MBEDTLS_CIPHER_CAMELLIA_128_GCM, /**< Camellia cipher with 128-bit GCM mode. */
133 MBEDTLS_CIPHER_CAMELLIA_192_GCM, /**< Camellia cipher with 192-bit GCM mode. */
134 MBEDTLS_CIPHER_CAMELLIA_256_GCM, /**< Camellia cipher with 256-bit GCM mode. */
135 MBEDTLS_CIPHER_DES_ECB, /**< DES cipher with ECB mode. */
136 MBEDTLS_CIPHER_DES_CBC, /**< DES cipher with CBC mode. */
137 MBEDTLS_CIPHER_DES_EDE_ECB, /**< DES cipher with EDE ECB mode. */
138 MBEDTLS_CIPHER_DES_EDE_CBC, /**< DES cipher with EDE CBC mode. */
139 MBEDTLS_CIPHER_DES_EDE3_ECB, /**< DES cipher with EDE3 ECB mode. */
140 MBEDTLS_CIPHER_DES_EDE3_CBC, /**< DES cipher with EDE3 CBC mode. */
141 MBEDTLS_CIPHER_BLOWFISH_ECB, /**< Blowfish cipher with ECB mode. */
142 MBEDTLS_CIPHER_BLOWFISH_CBC, /**< Blowfish cipher with CBC mode. */
143 MBEDTLS_CIPHER_BLOWFISH_CFB64, /**< Blowfish cipher with CFB64 mode. */
144 MBEDTLS_CIPHER_BLOWFISH_CTR, /**< Blowfish cipher with CTR mode. */
145 MBEDTLS_CIPHER_ARC4_128, /**< RC4 cipher with 128-bit mode. */
146 MBEDTLS_CIPHER_AES_128_CCM, /**< AES cipher with 128-bit CCM mode. */
147 MBEDTLS_CIPHER_AES_192_CCM, /**< AES cipher with 192-bit CCM mode. */
148 MBEDTLS_CIPHER_AES_256_CCM, /**< AES cipher with 256-bit CCM mode. */
149 MBEDTLS_CIPHER_CAMELLIA_128_CCM, /**< Camellia cipher with 128-bit CCM mode. */
150 MBEDTLS_CIPHER_CAMELLIA_192_CCM, /**< Camellia cipher with 192-bit CCM mode. */
151 MBEDTLS_CIPHER_CAMELLIA_256_CCM, /**< Camellia cipher with 256-bit CCM 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_AES_128_OFB, /**< AES 128-bit cipher in OFB mode. */
171 MBEDTLS_CIPHER_AES_192_OFB, /**< AES 192-bit cipher in OFB mode. */
172 MBEDTLS_CIPHER_AES_256_OFB, /**< AES 256-bit cipher in OFB mode. */
173 MBEDTLS_CIPHER_AES_128_XTS, /**< AES 128-bit cipher in XTS block mode. */
174 MBEDTLS_CIPHER_AES_256_XTS, /**< AES 256-bit cipher in XTS block mode. */
175 MBEDTLS_CIPHER_CHACHA20, /**< ChaCha20 stream cipher. */
176 MBEDTLS_CIPHER_CHACHA20_POLY1305, /**< ChaCha20-Poly1305 AEAD cipher. */
177 MBEDTLS_CIPHER_AES_128_KW, /**< AES cipher with 128-bit NIST KW mode. */
178 MBEDTLS_CIPHER_AES_192_KW, /**< AES cipher with 192-bit NIST KW mode. */
179 MBEDTLS_CIPHER_AES_256_KW, /**< AES cipher with 256-bit NIST KW mode. */
180 MBEDTLS_CIPHER_AES_128_KWP, /**< AES cipher with 128-bit NIST KWP mode. */
181 MBEDTLS_CIPHER_AES_192_KWP, /**< AES cipher with 192-bit NIST KWP mode. */
182 MBEDTLS_CIPHER_AES_256_KWP, /**< AES cipher with 256-bit NIST KWP mode. */
183 } mbedtls_cipher_type_t;
184
185 /** Supported cipher modes. */
186 typedef enum {
187 MBEDTLS_MODE_NONE = 0, /**< None. */
188 MBEDTLS_MODE_ECB, /**< The ECB cipher mode. */
189 MBEDTLS_MODE_CBC, /**< The CBC cipher mode. */
190 MBEDTLS_MODE_CFB, /**< The CFB cipher mode. */
191 MBEDTLS_MODE_OFB, /**< The OFB cipher mode. */
192 MBEDTLS_MODE_CTR, /**< The CTR cipher mode. */
193 MBEDTLS_MODE_GCM, /**< The GCM cipher mode. */
194 MBEDTLS_MODE_STREAM, /**< The stream cipher mode. */
195 MBEDTLS_MODE_CCM, /**< The CCM cipher mode. */
196 MBEDTLS_MODE_XTS, /**< The XTS cipher mode. */
197 MBEDTLS_MODE_CHACHAPOLY, /**< The ChaCha-Poly cipher mode. */
198 MBEDTLS_MODE_KW, /**< The SP800-38F KW mode */
199 MBEDTLS_MODE_KWP, /**< The SP800-38F KWP mode */
200 } mbedtls_cipher_mode_t;
201
202 /** Supported cipher padding types. */
203 typedef enum {
204 MBEDTLS_PADDING_PKCS7 = 0, /**< PKCS7 padding (default). */
205 MBEDTLS_PADDING_ONE_AND_ZEROS, /**< ISO/IEC 7816-4 padding. */
206 MBEDTLS_PADDING_ZEROS_AND_LEN, /**< ANSI X.923 padding. */
207 MBEDTLS_PADDING_ZEROS, /**< Zero padding (not reversible). */
208 MBEDTLS_PADDING_NONE, /**< Never pad (full blocks only). */
209 } mbedtls_cipher_padding_t;
210
211 /** Type of operation. */
212 typedef enum {
213 MBEDTLS_OPERATION_NONE = -1,
214 MBEDTLS_DECRYPT = 0,
215 MBEDTLS_ENCRYPT,
216 } mbedtls_operation_t;
217
218 enum {
219 /** Undefined key length. */
220 MBEDTLS_KEY_LENGTH_NONE = 0,
221 /** Key length, in bits (including parity), for DES keys. */
222 MBEDTLS_KEY_LENGTH_DES = 64,
223 /** Key length in bits, including parity, for DES in two-key EDE. */
224 MBEDTLS_KEY_LENGTH_DES_EDE = 128,
225 /** Key length in bits, including parity, for DES in three-key EDE. */
226 MBEDTLS_KEY_LENGTH_DES_EDE3 = 192,
227 };
228
229 /** Maximum length of any IV, in Bytes. */
230 /* This should ideally be derived automatically from list of ciphers.
231 * This should be kept in sync with MBEDTLS_SSL_MAX_IV_LENGTH defined
232 * in ssl_internal.h. */
233 #define MBEDTLS_MAX_IV_LENGTH 16
234
235 /** Maximum block size of any cipher, in Bytes. */
236 /* This should ideally be derived automatically from list of ciphers.
237 * This should be kept in sync with MBEDTLS_SSL_MAX_BLOCK_LENGTH defined
238 * in ssl_internal.h. */
239 #define MBEDTLS_MAX_BLOCK_LENGTH 16
240
241 /** Maximum key length, in Bytes. */
242 /* This should ideally be derived automatically from list of ciphers.
243 * For now, only check whether XTS is enabled which uses 64 Byte keys,
244 * and use 32 Bytes as an upper bound for the maximum key length otherwise.
245 * This should be kept in sync with MBEDTLS_SSL_MAX_BLOCK_LENGTH defined
246 * in ssl_internal.h, which however deliberately ignores the case of XTS
247 * since the latter isn't used in SSL/TLS. */
248 #if defined(MBEDTLS_CIPHER_MODE_XTS)
249 #define MBEDTLS_MAX_KEY_LENGTH 64
250 #else
251 #define MBEDTLS_MAX_KEY_LENGTH 32
252 #endif /* MBEDTLS_CIPHER_MODE_XTS */
253
254 /**
255 * Base cipher information (opaque struct).
256 */
257 typedef struct mbedtls_cipher_base_t mbedtls_cipher_base_t;
258
259 /**
260 * CMAC context (opaque struct).
261 */
262 typedef struct mbedtls_cmac_context_t mbedtls_cmac_context_t;
263
264 /**
265 * Cipher information. Allows calling cipher functions
266 * in a generic way.
267 */
268 typedef struct mbedtls_cipher_info_t
269 {
270 /** Full cipher identifier. For example,
271 * MBEDTLS_CIPHER_AES_256_CBC.
272 */
273 mbedtls_cipher_type_t type;
274
275 /** The cipher mode. For example, MBEDTLS_MODE_CBC. */
276 mbedtls_cipher_mode_t mode;
277
278 /** The cipher key length, in bits. This is the
279 * default length for variable sized ciphers.
280 * Includes parity bits for ciphers like DES.
281 */
282 unsigned int key_bitlen;
283
284 /** Name of the cipher. */
285 const char * name;
286
287 /** IV or nonce size, in Bytes.
288 * For ciphers that accept variable IV sizes,
289 * this is the recommended size.
290 */
291 unsigned int iv_size;
292
293 /** Bitflag comprised of MBEDTLS_CIPHER_VARIABLE_IV_LEN and
294 * MBEDTLS_CIPHER_VARIABLE_KEY_LEN indicating whether the
295 * cipher supports variable IV or variable key sizes, respectively.
296 */
297 int flags;
298
299 /** The block size, in Bytes. */
300 unsigned int block_size;
301
302 /** Struct for base cipher information and functions. */
303 const mbedtls_cipher_base_t *base;
304
305 } mbedtls_cipher_info_t;
306
307 /**
308 * Generic cipher context.
309 */
310 typedef struct mbedtls_cipher_context_t
311 {
312 /** Information about the associated cipher. */
313 const mbedtls_cipher_info_t *cipher_info;
314
315 /** Key length to use. */
316 int key_bitlen;
317
318 /** Operation that the key of the context has been
319 * initialized for.
320 */
321 mbedtls_operation_t operation;
322
323 #if defined(MBEDTLS_CIPHER_MODE_WITH_PADDING)
324 /** Padding functions to use, if relevant for
325 * the specific cipher mode.
326 */
327 void (*add_padding)( unsigned char *output, size_t olen, size_t data_len );
328 int (*get_padding)( unsigned char *input, size_t ilen, size_t *data_len );
329 #endif
330
331 /** Buffer for input that has not been processed yet. */
332 unsigned char unprocessed_data[MBEDTLS_MAX_BLOCK_LENGTH];
333
334 /** Number of Bytes that have not been processed yet. */
335 size_t unprocessed_len;
336
337 /** Current IV or NONCE_COUNTER for CTR-mode, data unit (or sector) number
338 * for XTS-mode. */
339 unsigned char iv[MBEDTLS_MAX_IV_LENGTH];
340
341 /** IV size in Bytes, for ciphers with variable-length IVs. */
342 size_t iv_size;
343
344 /** The cipher-specific context. */
345 void *cipher_ctx;
346
347 #if defined(MBEDTLS_CMAC_C)
348 /** CMAC-specific context. */
349 mbedtls_cmac_context_t *cmac_ctx;
350 #endif
351
352 #if defined(MBEDTLS_USE_PSA_CRYPTO)
353 /** Indicates whether the cipher operations should be performed
354 * by Mbed TLS' own crypto library or an external implementation
355 * of the PSA Crypto API.
356 * This is unset if the cipher context was established through
357 * mbedtls_cipher_setup(), and set if it was established through
358 * mbedtls_cipher_setup_psa().
359 */
360 unsigned char psa_enabled;
361 #endif /* MBEDTLS_USE_PSA_CRYPTO */
362
363 } mbedtls_cipher_context_t;
364
365 /**
366 * \brief This function retrieves the list of ciphers supported
367 * by the generic cipher module.
368 *
369 * For any cipher identifier in the returned list, you can
370 * obtain the corresponding generic cipher information structure
371 * via mbedtls_cipher_info_from_type(), which can then be used
372 * to prepare a cipher context via mbedtls_cipher_setup().
373 *
374 *
375 * \return A statically-allocated array of cipher identifiers
376 * of type cipher_type_t. The last entry is zero.
377 */
378 const int *mbedtls_cipher_list( void );
379
380 /**
381 * \brief This function retrieves the cipher-information
382 * structure associated with the given cipher name.
383 *
384 * \param cipher_name Name of the cipher to search for. This must not be
385 * \c NULL.
386 *
387 * \return The cipher information structure associated with the
388 * given \p cipher_name.
389 * \return \c NULL if the associated cipher information is not found.
390 */
391 const mbedtls_cipher_info_t *mbedtls_cipher_info_from_string( const char *cipher_name );
392
393 /**
394 * \brief This function retrieves the cipher-information
395 * structure associated with the given cipher type.
396 *
397 * \param cipher_type Type of the cipher to search for.
398 *
399 * \return The cipher information structure associated with the
400 * given \p cipher_type.
401 * \return \c NULL if the associated cipher information is not found.
402 */
403 const mbedtls_cipher_info_t *mbedtls_cipher_info_from_type( const mbedtls_cipher_type_t cipher_type );
404
405 /**
406 * \brief This function retrieves the cipher-information
407 * structure associated with the given cipher ID,
408 * key size and mode.
409 *
410 * \param cipher_id The ID of the cipher to search for. For example,
411 * #MBEDTLS_CIPHER_ID_AES.
412 * \param key_bitlen The length of the key in bits.
413 * \param mode The cipher mode. For example, #MBEDTLS_MODE_CBC.
414 *
415 * \return The cipher information structure associated with the
416 * given \p cipher_id.
417 * \return \c NULL if the associated cipher information is not found.
418 */
419 const mbedtls_cipher_info_t *mbedtls_cipher_info_from_values( const mbedtls_cipher_id_t cipher_id,
420 int key_bitlen,
421 const mbedtls_cipher_mode_t mode );
422
423 /**
424 * \brief This function initializes a \p cipher_context as NONE.
425 *
426 * \param ctx The context to be initialized. This must not be \c NULL.
427 */
428 void mbedtls_cipher_init( mbedtls_cipher_context_t *ctx );
429
430 /**
431 * \brief This function frees and clears the cipher-specific
432 * context of \p ctx. Freeing \p ctx itself remains the
433 * responsibility of the caller.
434 *
435 * \param ctx The context to be freed. If this is \c NULL, the
436 * function has no effect, otherwise this must point to an
437 * initialized context.
438 */
439 void mbedtls_cipher_free( mbedtls_cipher_context_t *ctx );
440
441
442 /**
443 * \brief This function initializes a cipher context for
444 * use with the given cipher primitive.
445 *
446 * \param ctx The context to initialize. This must be initialized.
447 * \param cipher_info The cipher to use.
448 *
449 * \return \c 0 on success.
450 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
451 * parameter-verification failure.
452 * \return #MBEDTLS_ERR_CIPHER_ALLOC_FAILED if allocation of the
453 * cipher-specific context fails.
454 *
455 * \internal Currently, the function also clears the structure.
456 * In future versions, the caller will be required to call
457 * mbedtls_cipher_init() on the structure first.
458 */
459 int mbedtls_cipher_setup( mbedtls_cipher_context_t *ctx,
460 const mbedtls_cipher_info_t *cipher_info );
461
462 #if defined(MBEDTLS_USE_PSA_CRYPTO)
463 /**
464 * \brief This function initializes a cipher context for
465 * PSA-based use with the given cipher primitive.
466 *
467 * \note See #MBEDTLS_USE_PSA_CRYPTO for information on PSA.
468 *
469 * \param ctx The context to initialize. May not be \c NULL.
470 * \param cipher_info The cipher to use.
471 * \param taglen For AEAD ciphers, the length in bytes of the
472 * authentication tag to use. Subsequent uses of
473 * mbedtls_cipher_auth_encrypt() or
474 * mbedtls_cipher_auth_decrypt() must provide
475 * the same tag length.
476 * For non-AEAD ciphers, the value must be \c 0.
477 *
478 * \return \c 0 on success.
479 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
480 * parameter-verification failure.
481 * \return #MBEDTLS_ERR_CIPHER_ALLOC_FAILED if allocation of the
482 * cipher-specific context fails.
483 */
484 int mbedtls_cipher_setup_psa( mbedtls_cipher_context_t *ctx,
485 const mbedtls_cipher_info_t *cipher_info,
486 size_t taglen );
487 #endif /* MBEDTLS_USE_PSA_CRYPTO */
488
489 /**
490 * \brief This function returns the block size of the given cipher.
491 *
492 * \param ctx The context of the cipher. This must be initialized.
493 *
494 * \return The block size of the underlying cipher.
495 * \return \c 0 if \p ctx has not been initialized.
496 */
mbedtls_cipher_get_block_size(const mbedtls_cipher_context_t * ctx)497 static inline unsigned int mbedtls_cipher_get_block_size(
498 const mbedtls_cipher_context_t *ctx )
499 {
500 MBEDTLS_INTERNAL_VALIDATE_RET( ctx != NULL, 0 );
501 if( ctx->cipher_info == NULL )
502 return 0;
503
504 return ctx->cipher_info->block_size;
505 }
506
507 /**
508 * \brief This function returns the mode of operation for
509 * the cipher. For example, MBEDTLS_MODE_CBC.
510 *
511 * \param ctx The context of the cipher. This must be initialized.
512 *
513 * \return The mode of operation.
514 * \return #MBEDTLS_MODE_NONE if \p ctx has not been initialized.
515 */
mbedtls_cipher_get_cipher_mode(const mbedtls_cipher_context_t * ctx)516 static inline mbedtls_cipher_mode_t mbedtls_cipher_get_cipher_mode(
517 const mbedtls_cipher_context_t *ctx )
518 {
519 MBEDTLS_INTERNAL_VALIDATE_RET( ctx != NULL, MBEDTLS_MODE_NONE );
520 if( ctx->cipher_info == NULL )
521 return MBEDTLS_MODE_NONE;
522
523 return ctx->cipher_info->mode;
524 }
525
526 /**
527 * \brief This function returns the size of the IV or nonce
528 * of the cipher, in Bytes.
529 *
530 * \param ctx The context of the cipher. This must be initialized.
531 *
532 * \return The recommended IV size if no IV has been set.
533 * \return \c 0 for ciphers not using an IV or a nonce.
534 * \return The actual size if an IV has been set.
535 */
mbedtls_cipher_get_iv_size(const mbedtls_cipher_context_t * ctx)536 static inline int mbedtls_cipher_get_iv_size(
537 const mbedtls_cipher_context_t *ctx )
538 {
539 MBEDTLS_INTERNAL_VALIDATE_RET( ctx != NULL, 0 );
540 if( ctx->cipher_info == NULL )
541 return 0;
542
543 if( ctx->iv_size != 0 )
544 return (int) ctx->iv_size;
545
546 return (int) ctx->cipher_info->iv_size;
547 }
548
549 /**
550 * \brief This function returns the type of the given cipher.
551 *
552 * \param ctx The context of the cipher. This must be initialized.
553 *
554 * \return The type of the cipher.
555 * \return #MBEDTLS_CIPHER_NONE if \p ctx has not been initialized.
556 */
mbedtls_cipher_get_type(const mbedtls_cipher_context_t * ctx)557 static inline mbedtls_cipher_type_t mbedtls_cipher_get_type(
558 const mbedtls_cipher_context_t *ctx )
559 {
560 MBEDTLS_INTERNAL_VALIDATE_RET(
561 ctx != NULL, MBEDTLS_CIPHER_NONE );
562 if( ctx->cipher_info == NULL )
563 return MBEDTLS_CIPHER_NONE;
564
565 return ctx->cipher_info->type;
566 }
567
568 /**
569 * \brief This function returns the name of the given cipher
570 * as a string.
571 *
572 * \param ctx The context of the cipher. This must be initialized.
573 *
574 * \return The name of the cipher.
575 * \return NULL if \p ctx has not been not initialized.
576 */
mbedtls_cipher_get_name(const mbedtls_cipher_context_t * ctx)577 static inline const char *mbedtls_cipher_get_name(
578 const mbedtls_cipher_context_t *ctx )
579 {
580 MBEDTLS_INTERNAL_VALIDATE_RET( ctx != NULL, 0 );
581 if( ctx->cipher_info == NULL )
582 return 0;
583
584 return ctx->cipher_info->name;
585 }
586
587 /**
588 * \brief This function returns the key length of the cipher.
589 *
590 * \param ctx The context of the cipher. This must be initialized.
591 *
592 * \return The key length of the cipher in bits.
593 * \return #MBEDTLS_KEY_LENGTH_NONE if ctx \p has not been
594 * initialized.
595 */
mbedtls_cipher_get_key_bitlen(const mbedtls_cipher_context_t * ctx)596 static inline int mbedtls_cipher_get_key_bitlen(
597 const mbedtls_cipher_context_t *ctx )
598 {
599 MBEDTLS_INTERNAL_VALIDATE_RET(
600 ctx != NULL, MBEDTLS_KEY_LENGTH_NONE );
601 if( ctx->cipher_info == NULL )
602 return MBEDTLS_KEY_LENGTH_NONE;
603
604 return (int) ctx->cipher_info->key_bitlen;
605 }
606
607 /**
608 * \brief This function returns the operation of the given cipher.
609 *
610 * \param ctx The context of the cipher. This must be initialized.
611 *
612 * \return The type of operation: #MBEDTLS_ENCRYPT or #MBEDTLS_DECRYPT.
613 * \return #MBEDTLS_OPERATION_NONE if \p ctx has not been initialized.
614 */
mbedtls_cipher_get_operation(const mbedtls_cipher_context_t * ctx)615 static inline mbedtls_operation_t mbedtls_cipher_get_operation(
616 const mbedtls_cipher_context_t *ctx )
617 {
618 MBEDTLS_INTERNAL_VALIDATE_RET(
619 ctx != NULL, MBEDTLS_OPERATION_NONE );
620 if( ctx->cipher_info == NULL )
621 return MBEDTLS_OPERATION_NONE;
622
623 return ctx->operation;
624 }
625
626 /**
627 * \brief This function sets the key to use with the given context.
628 *
629 * \param ctx The generic cipher context. This must be initialized and
630 * bound to a cipher information structure.
631 * \param key The key to use. This must be a readable buffer of at
632 * least \p key_bitlen Bits.
633 * \param key_bitlen The key length to use, in Bits.
634 * \param operation The operation that the key will be used for:
635 * #MBEDTLS_ENCRYPT or #MBEDTLS_DECRYPT.
636 *
637 * \return \c 0 on success.
638 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
639 * parameter-verification failure.
640 * \return A cipher-specific error code on failure.
641 */
642 int mbedtls_cipher_setkey( mbedtls_cipher_context_t *ctx,
643 const unsigned char *key,
644 int key_bitlen,
645 const mbedtls_operation_t operation );
646
647 #if defined(MBEDTLS_CIPHER_MODE_WITH_PADDING)
648 /**
649 * \brief This function sets the padding mode, for cipher modes
650 * that use padding.
651 *
652 * The default passing mode is PKCS7 padding.
653 *
654 * \param ctx The generic cipher context. This must be initialized and
655 * bound to a cipher information structure.
656 * \param mode The padding mode.
657 *
658 * \return \c 0 on success.
659 * \return #MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE
660 * if the selected padding mode is not supported.
661 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA if the cipher mode
662 * does not support padding.
663 */
664 int mbedtls_cipher_set_padding_mode( mbedtls_cipher_context_t *ctx,
665 mbedtls_cipher_padding_t mode );
666 #endif /* MBEDTLS_CIPHER_MODE_WITH_PADDING */
667
668 /**
669 * \brief This function sets the initialization vector (IV)
670 * or nonce.
671 *
672 * \note Some ciphers do not use IVs nor nonce. For these
673 * ciphers, this function has no effect.
674 *
675 * \param ctx The generic cipher context. This must be initialized and
676 * bound to a cipher information structure.
677 * \param iv The IV to use, or NONCE_COUNTER for CTR-mode ciphers. This
678 * must be a readable buffer of at least \p iv_len Bytes.
679 * \param iv_len The IV length for ciphers with variable-size IV.
680 * This parameter is discarded by ciphers with fixed-size IV.
681 *
682 * \return \c 0 on success.
683 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
684 * parameter-verification failure.
685 */
686 int mbedtls_cipher_set_iv( mbedtls_cipher_context_t *ctx,
687 const unsigned char *iv,
688 size_t iv_len );
689
690 /**
691 * \brief This function resets the cipher state.
692 *
693 * \param ctx The generic cipher context. This must be initialized.
694 *
695 * \return \c 0 on success.
696 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
697 * parameter-verification failure.
698 */
699 int mbedtls_cipher_reset( mbedtls_cipher_context_t *ctx );
700
701 #if defined(MBEDTLS_GCM_C) || defined(MBEDTLS_CHACHAPOLY_C)
702 /**
703 * \brief This function adds additional data for AEAD ciphers.
704 * Currently supported with GCM and ChaCha20+Poly1305.
705 * This must be called exactly once, after
706 * mbedtls_cipher_reset().
707 *
708 * \param ctx The generic cipher context. This must be initialized.
709 * \param ad The additional data to use. This must be a readable
710 * buffer of at least \p ad_len Bytes.
711 * \param ad_len The length of \p ad in Bytes.
712 *
713 * \return \c 0 on success.
714 * \return A specific error code on failure.
715 */
716 int mbedtls_cipher_update_ad( mbedtls_cipher_context_t *ctx,
717 const unsigned char *ad, size_t ad_len );
718 #endif /* MBEDTLS_GCM_C || MBEDTLS_CHACHAPOLY_C */
719
720 /**
721 * \brief The generic cipher update function. It encrypts or
722 * decrypts using the given cipher context. Writes as
723 * many block-sized blocks of data as possible to output.
724 * Any data that cannot be written immediately is either
725 * added to the next block, or flushed when
726 * mbedtls_cipher_finish() is called.
727 * Exception: For MBEDTLS_MODE_ECB, expects a single block
728 * in size. For example, 16 Bytes for AES.
729 *
730 * \note If the underlying cipher is used in GCM mode, all calls
731 * to this function, except for the last one before
732 * mbedtls_cipher_finish(), must have \p ilen as a
733 * multiple of the block size of the cipher.
734 *
735 * \param ctx The generic cipher context. This must be initialized and
736 * bound to a key.
737 * \param input The buffer holding the input data. This must be a
738 * readable buffer of at least \p ilen Bytes.
739 * \param ilen The length of the input data.
740 * \param output The buffer for the output data. This must be able to
741 * hold at least `ilen + block_size`. This must not be the
742 * same buffer as \p input.
743 * \param olen The length of the output data, to be updated with the
744 * actual number of Bytes written. This must not be
745 * \c NULL.
746 *
747 * \return \c 0 on success.
748 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
749 * parameter-verification failure.
750 * \return #MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE on an
751 * unsupported mode for a cipher.
752 * \return A cipher-specific error code on failure.
753 */
754 int mbedtls_cipher_update( mbedtls_cipher_context_t *ctx,
755 const unsigned char *input,
756 size_t ilen, unsigned char *output,
757 size_t *olen );
758
759 /**
760 * \brief The generic cipher finalization function. If data still
761 * needs to be flushed from an incomplete block, the data
762 * contained in it is padded to the size of
763 * the last block, and written to the \p output buffer.
764 *
765 * \param ctx The generic cipher context. This must be initialized and
766 * bound to a key.
767 * \param output The buffer to write data to. This needs to be a writable
768 * buffer of at least \p block_size Bytes.
769 * \param olen The length of the data written to the \p output buffer.
770 * This may not be \c NULL.
771 *
772 * \return \c 0 on success.
773 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
774 * parameter-verification failure.
775 * \return #MBEDTLS_ERR_CIPHER_FULL_BLOCK_EXPECTED on decryption
776 * expecting a full block but not receiving one.
777 * \return #MBEDTLS_ERR_CIPHER_INVALID_PADDING on invalid padding
778 * while decrypting.
779 * \return A cipher-specific error code on failure.
780 */
781 int mbedtls_cipher_finish( mbedtls_cipher_context_t *ctx,
782 unsigned char *output, size_t *olen );
783
784 #if defined(MBEDTLS_GCM_C) || defined(MBEDTLS_CHACHAPOLY_C)
785 /**
786 * \brief This function writes a tag for AEAD ciphers.
787 * Currently supported with GCM and ChaCha20+Poly1305.
788 * This must be called after mbedtls_cipher_finish().
789 *
790 * \param ctx The generic cipher context. This must be initialized,
791 * bound to a key, and have just completed a cipher
792 * operation through mbedtls_cipher_finish() the tag for
793 * which should be written.
794 * \param tag The buffer to write the tag to. This must be a writable
795 * buffer of at least \p tag_len Bytes.
796 * \param tag_len The length of the tag to write.
797 *
798 * \return \c 0 on success.
799 * \return A specific error code on failure.
800 */
801 int mbedtls_cipher_write_tag( mbedtls_cipher_context_t *ctx,
802 unsigned char *tag, size_t tag_len );
803
804 /**
805 * \brief This function checks the tag for AEAD ciphers.
806 * Currently supported with GCM and ChaCha20+Poly1305.
807 * This must be called after mbedtls_cipher_finish().
808 *
809 * \param ctx The generic cipher context. This must be initialized.
810 * \param tag The buffer holding the tag. This must be a readable
811 * buffer of at least \p tag_len Bytes.
812 * \param tag_len The length of the tag to check.
813 *
814 * \return \c 0 on success.
815 * \return A specific error code on failure.
816 */
817 int mbedtls_cipher_check_tag( mbedtls_cipher_context_t *ctx,
818 const unsigned char *tag, size_t tag_len );
819 #endif /* MBEDTLS_GCM_C || MBEDTLS_CHACHAPOLY_C */
820
821 /**
822 * \brief The generic all-in-one encryption/decryption function,
823 * for all ciphers except AEAD constructs.
824 *
825 * \param ctx The generic cipher context. This must be initialized.
826 * \param iv The IV to use, or NONCE_COUNTER for CTR-mode ciphers.
827 * This must be a readable buffer of at least \p iv_len
828 * Bytes.
829 * \param iv_len The IV length for ciphers with variable-size IV.
830 * This parameter is discarded by ciphers with fixed-size
831 * IV.
832 * \param input The buffer holding the input data. This must be a
833 * readable buffer of at least \p ilen Bytes.
834 * \param ilen The length of the input data in Bytes.
835 * \param output The buffer for the output data. This must be able to
836 * hold at least `ilen + block_size`. This must not be the
837 * same buffer as \p input.
838 * \param olen The length of the output data, to be updated with the
839 * actual number of Bytes written. This must not be
840 * \c NULL.
841 *
842 * \note Some ciphers do not use IVs nor nonce. For these
843 * ciphers, use \p iv = NULL and \p iv_len = 0.
844 *
845 * \return \c 0 on success.
846 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
847 * parameter-verification failure.
848 * \return #MBEDTLS_ERR_CIPHER_FULL_BLOCK_EXPECTED on decryption
849 * expecting a full block but not receiving one.
850 * \return #MBEDTLS_ERR_CIPHER_INVALID_PADDING on invalid padding
851 * while decrypting.
852 * \return A cipher-specific error code on failure.
853 */
854 int mbedtls_cipher_crypt( mbedtls_cipher_context_t *ctx,
855 const unsigned char *iv, size_t iv_len,
856 const unsigned char *input, size_t ilen,
857 unsigned char *output, size_t *olen );
858
859 #if defined(MBEDTLS_CIPHER_MODE_AEAD)
860 #if ! defined(MBEDTLS_DEPRECATED_REMOVED)
861 #if defined(MBEDTLS_DEPRECATED_WARNING)
862 #define MBEDTLS_DEPRECATED __attribute__((deprecated))
863 #else
864 #define MBEDTLS_DEPRECATED
865 #endif /* MBEDTLS_DEPRECATED_WARNING */
866 /**
867 * \brief The generic authenticated encryption (AEAD) function.
868 *
869 * \deprecated Superseded by mbedtls_cipher_auth_encrypt_ext().
870 *
871 * \note This function only supports AEAD algorithms, not key
872 * wrapping algorithms such as NIST_KW; for this, see
873 * mbedtls_cipher_auth_encrypt_ext().
874 *
875 * \param ctx The generic cipher context. This must be initialized and
876 * bound to a key associated with an AEAD algorithm.
877 * \param iv The nonce to use. This must be a readable buffer of
878 * at least \p iv_len Bytes and must not be \c NULL.
879 * \param iv_len The length of the nonce. This must satisfy the
880 * constraints imposed by the AEAD cipher used.
881 * \param ad The additional data to authenticate. This must be a
882 * readable buffer of at least \p ad_len Bytes, and may
883 * be \c NULL is \p ad_len is \c 0.
884 * \param ad_len The length of \p ad.
885 * \param input The buffer holding the input data. This must be a
886 * readable buffer of at least \p ilen Bytes, and may be
887 * \c NULL if \p ilen is \c 0.
888 * \param ilen The length of the input data.
889 * \param output The buffer for the output data. This must be a
890 * writable buffer of at least \p ilen Bytes, and must
891 * not be \c NULL.
892 * \param olen This will be filled with the actual number of Bytes
893 * written to the \p output buffer. This must point to a
894 * writable object of type \c size_t.
895 * \param tag The buffer for the authentication tag. This must be a
896 * writable buffer of at least \p tag_len Bytes. See note
897 * below regarding restrictions with PSA-based contexts.
898 * \param tag_len The desired length of the authentication tag. This
899 * must match the constraints imposed by the AEAD cipher
900 * used, and in particular must not be \c 0.
901 *
902 * \note If the context is based on PSA (that is, it was set up
903 * with mbedtls_cipher_setup_psa()), then it is required
904 * that \c tag == output + ilen. That is, the tag must be
905 * appended to the ciphertext as recommended by RFC 5116.
906 *
907 * \return \c 0 on success.
908 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
909 * parameter-verification failure.
910 * \return A cipher-specific error code on failure.
911 */
912 int mbedtls_cipher_auth_encrypt( mbedtls_cipher_context_t *ctx,
913 const unsigned char *iv, size_t iv_len,
914 const unsigned char *ad, size_t ad_len,
915 const unsigned char *input, size_t ilen,
916 unsigned char *output, size_t *olen,
917 unsigned char *tag, size_t tag_len )
918 MBEDTLS_DEPRECATED;
919
920 /**
921 * \brief The generic authenticated decryption (AEAD) function.
922 *
923 * \deprecated Superseded by mbedtls_cipher_auth_decrypt_ext().
924 *
925 * \note This function only supports AEAD algorithms, not key
926 * wrapping algorithms such as NIST_KW; for this, see
927 * mbedtls_cipher_auth_decrypt_ext().
928 *
929 * \note If the data is not authentic, then the output buffer
930 * is zeroed out to prevent the unauthentic plaintext being
931 * used, making this interface safer.
932 *
933 * \param ctx The generic cipher context. This must be initialized and
934 * bound to a key associated with an AEAD algorithm.
935 * \param iv The nonce to use. This must be a readable buffer of
936 * at least \p iv_len Bytes and must not be \c NULL.
937 * \param iv_len The length of the nonce. This must satisfy the
938 * constraints imposed by the AEAD cipher used.
939 * \param ad The additional data to authenticate. This must be a
940 * readable buffer of at least \p ad_len Bytes, and may
941 * be \c NULL is \p ad_len is \c 0.
942 * \param ad_len The length of \p ad.
943 * \param input The buffer holding the input data. This must be a
944 * readable buffer of at least \p ilen Bytes, and may be
945 * \c NULL if \p ilen is \c 0.
946 * \param ilen The length of the input data.
947 * \param output The buffer for the output data. This must be a
948 * writable buffer of at least \p ilen Bytes, and must
949 * not be \c NULL.
950 * \param olen This will be filled with the actual number of Bytes
951 * written to the \p output buffer. This must point to a
952 * writable object of type \c size_t.
953 * \param tag The buffer for the authentication tag. This must be a
954 * readable buffer of at least \p tag_len Bytes. See note
955 * below regarding restrictions with PSA-based contexts.
956 * \param tag_len The length of the authentication tag. This must match
957 * the constraints imposed by the AEAD cipher used, and in
958 * particular must not be \c 0.
959 *
960 * \note If the context is based on PSA (that is, it was set up
961 * with mbedtls_cipher_setup_psa()), then it is required
962 * that \c tag == input + len. That is, the tag must be
963 * appended to the ciphertext as recommended by RFC 5116.
964 *
965 * \return \c 0 on success.
966 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
967 * parameter-verification failure.
968 * \return #MBEDTLS_ERR_CIPHER_AUTH_FAILED if data is not authentic.
969 * \return A cipher-specific error code on failure.
970 */
971 int mbedtls_cipher_auth_decrypt( mbedtls_cipher_context_t *ctx,
972 const unsigned char *iv, size_t iv_len,
973 const unsigned char *ad, size_t ad_len,
974 const unsigned char *input, size_t ilen,
975 unsigned char *output, size_t *olen,
976 const unsigned char *tag, size_t tag_len )
977 MBEDTLS_DEPRECATED;
978 #undef MBEDTLS_DEPRECATED
979 #endif /* MBEDTLS_DEPRECATED_REMOVED */
980 #endif /* MBEDTLS_CIPHER_MODE_AEAD */
981
982 #if defined(MBEDTLS_CIPHER_MODE_AEAD) || defined(MBEDTLS_NIST_KW_C)
983 /**
984 * \brief The authenticated encryption (AEAD/NIST_KW) function.
985 *
986 * \note For AEAD modes, the tag will be appended to the
987 * ciphertext, as recommended by RFC 5116.
988 * (NIST_KW doesn't have a separate tag.)
989 *
990 * \param ctx The generic cipher context. This must be initialized and
991 * bound to a key, with an AEAD algorithm or NIST_KW.
992 * \param iv The nonce to use. This must be a readable buffer of
993 * at least \p iv_len Bytes and may be \c NULL if \p
994 * iv_len is \c 0.
995 * \param iv_len The length of the nonce. For AEAD ciphers, this must
996 * satisfy the constraints imposed by the cipher used.
997 * For NIST_KW, this must be \c 0.
998 * \param ad The additional data to authenticate. This must be a
999 * readable buffer of at least \p ad_len Bytes, and may
1000 * be \c NULL is \p ad_len is \c 0.
1001 * \param ad_len The length of \p ad. For NIST_KW, this must be \c 0.
1002 * \param input The buffer holding the input data. This must be a
1003 * readable buffer of at least \p ilen Bytes, and may be
1004 * \c NULL if \p ilen is \c 0.
1005 * \param ilen The length of the input data.
1006 * \param output The buffer for the output data. This must be a
1007 * writable buffer of at least \p output_len Bytes, and
1008 * must not be \c NULL.
1009 * \param output_len The length of the \p output buffer in Bytes. For AEAD
1010 * ciphers, this must be at least \p ilen + \p tag_len.
1011 * For NIST_KW, this must be at least \p ilen + 8
1012 * (rounded up to a multiple of 8 if KWP is used);
1013 * \p ilen + 15 is always a safe value.
1014 * \param olen This will be filled with the actual number of Bytes
1015 * written to the \p output buffer. This must point to a
1016 * writable object of type \c size_t.
1017 * \param tag_len The desired length of the authentication tag. For AEAD
1018 * ciphers, this must match the constraints imposed by
1019 * the cipher used, and in particular must not be \c 0.
1020 * For NIST_KW, this must be \c 0.
1021 *
1022 * \return \c 0 on success.
1023 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
1024 * parameter-verification failure.
1025 * \return A cipher-specific error code on failure.
1026 */
1027 int mbedtls_cipher_auth_encrypt_ext( mbedtls_cipher_context_t *ctx,
1028 const unsigned char *iv, size_t iv_len,
1029 const unsigned char *ad, size_t ad_len,
1030 const unsigned char *input, size_t ilen,
1031 unsigned char *output, size_t output_len,
1032 size_t *olen, size_t tag_len );
1033
1034 /**
1035 * \brief The authenticated encryption (AEAD/NIST_KW) function.
1036 *
1037 * \note If the data is not authentic, then the output buffer
1038 * is zeroed out to prevent the unauthentic plaintext being
1039 * used, making this interface safer.
1040 *
1041 * \note For AEAD modes, the tag must be appended to the
1042 * ciphertext, as recommended by RFC 5116.
1043 * (NIST_KW doesn't have a separate tag.)
1044 *
1045 * \param ctx The generic cipher context. This must be initialized and
1046 * bound to a key, with an AEAD algorithm or NIST_KW.
1047 * \param iv The nonce to use. This must be a readable buffer of
1048 * at least \p iv_len Bytes and may be \c NULL if \p
1049 * iv_len is \c 0.
1050 * \param iv_len The length of the nonce. For AEAD ciphers, this must
1051 * satisfy the constraints imposed by the cipher used.
1052 * For NIST_KW, this must be \c 0.
1053 * \param ad The additional data to authenticate. This must be a
1054 * readable buffer of at least \p ad_len Bytes, and may
1055 * be \c NULL is \p ad_len is \c 0.
1056 * \param ad_len The length of \p ad. For NIST_KW, this must be \c 0.
1057 * \param input The buffer holding the input data. This must be a
1058 * readable buffer of at least \p ilen Bytes, and may be
1059 * \c NULL if \p ilen is \c 0.
1060 * \param ilen The length of the input data. For AEAD ciphers this
1061 * must be at least \p tag_len. For NIST_KW this must be
1062 * at least \c 8.
1063 * \param output The buffer for the output data. This must be a
1064 * writable buffer of at least \p output_len Bytes, and
1065 * may be \c NULL if \p output_len is \c 0.
1066 * \param output_len The length of the \p output buffer in Bytes. For AEAD
1067 * ciphers, this must be at least \p ilen - \p tag_len.
1068 * For NIST_KW, this must be at least \p ilen - 8.
1069 * \param olen This will be filled with the actual number of Bytes
1070 * written to the \p output buffer. This must point to a
1071 * writable object of type \c size_t.
1072 * \param tag_len The actual length of the authentication tag. For AEAD
1073 * ciphers, this must match the constraints imposed by
1074 * the cipher used, and in particular must not be \c 0.
1075 * For NIST_KW, this must be \c 0.
1076 *
1077 * \return \c 0 on success.
1078 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
1079 * parameter-verification failure.
1080 * \return #MBEDTLS_ERR_CIPHER_AUTH_FAILED if data is not authentic.
1081 * \return A cipher-specific error code on failure.
1082 */
1083 int mbedtls_cipher_auth_decrypt_ext( mbedtls_cipher_context_t *ctx,
1084 const unsigned char *iv, size_t iv_len,
1085 const unsigned char *ad, size_t ad_len,
1086 const unsigned char *input, size_t ilen,
1087 unsigned char *output, size_t output_len,
1088 size_t *olen, size_t tag_len );
1089 #endif /* MBEDTLS_CIPHER_MODE_AEAD || MBEDTLS_NIST_KW_C */
1090 #ifdef __cplusplus
1091 }
1092 #endif
1093
1094 #endif /* MBEDTLS_CIPHER_H */
1095
