1 /**
2 * \file cipher.h
3 *
4 * \brief Generic cipher wrapper.
5 *
6 * \author Adriaan de Jong <dejong@fox-it.com>
7 *
8 * Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
9 * SPDX-License-Identifier: Apache-2.0
10 *
11 * Licensed under the Apache License, Version 2.0 (the "License"); you may
12 * not use this file except in compliance with the License.
13 * You may obtain a copy of the License at
14 *
15 * http://www.apache.org/licenses/LICENSE-2.0
16 *
17 * Unless required by applicable law or agreed to in writing, software
18 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
19 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
20 * See the License for the specific language governing permissions and
21 * limitations under the License.
22 *
23 * This file is part of mbed TLS (https://tls.mbed.org)
24 */
25
26 #ifndef MBEDTLS_CIPHER_H
27 #define MBEDTLS_CIPHER_H
28
29 #if !defined(MBEDTLS_CONFIG_FILE)
30 #include "config.h"
31 #else
32 #include MBEDTLS_CONFIG_FILE
33 #endif
34
35 #include <stddef.h>
36
37 #if defined(MBEDTLS_GCM_C) || defined(MBEDTLS_CCM_C)
38 #define MBEDTLS_CIPHER_MODE_AEAD
39 #endif
40
41 #if defined(MBEDTLS_CIPHER_MODE_CBC)
42 #define MBEDTLS_CIPHER_MODE_WITH_PADDING
43 #endif
44
45 #if defined(MBEDTLS_ARC4_C)
46 #define MBEDTLS_CIPHER_MODE_STREAM
47 #endif
48
49 #if ( defined(__ARMCC_VERSION) || defined(_MSC_VER) ) && \
50 !defined(inline) && !defined(__cplusplus)
51 #define inline __inline
52 #endif
53
54 #define MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE -0x6080 /**< The selected feature is not available. */
55 #define MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA -0x6100 /**< Bad input parameters to function. */
56 #define MBEDTLS_ERR_CIPHER_ALLOC_FAILED -0x6180 /**< Failed to allocate memory. */
57 #define MBEDTLS_ERR_CIPHER_INVALID_PADDING -0x6200 /**< Input data contains invalid padding and is rejected. */
58 #define MBEDTLS_ERR_CIPHER_FULL_BLOCK_EXPECTED -0x6280 /**< Decryption of block requires a full block. */
59 #define MBEDTLS_ERR_CIPHER_AUTH_FAILED -0x6300 /**< Authentication failed (for AEAD modes). */
60 #define MBEDTLS_ERR_CIPHER_INVALID_CONTEXT -0x6380 /**< The context is invalid, eg because it was free()ed. */
61
62 #define MBEDTLS_CIPHER_VARIABLE_IV_LEN 0x01 /**< Cipher accepts IVs of variable length */
63 #define MBEDTLS_CIPHER_VARIABLE_KEY_LEN 0x02 /**< Cipher accepts keys of variable length */
64
65 #ifdef __cplusplus
66 extern "C" {
67 #endif
68
69 typedef enum {
70 MBEDTLS_CIPHER_ID_NONE = 0,
71 MBEDTLS_CIPHER_ID_NULL,
72 MBEDTLS_CIPHER_ID_AES,
73 MBEDTLS_CIPHER_ID_DES,
74 MBEDTLS_CIPHER_ID_3DES,
75 MBEDTLS_CIPHER_ID_CAMELLIA,
76 MBEDTLS_CIPHER_ID_BLOWFISH,
77 MBEDTLS_CIPHER_ID_ARC4,
78 } mbedtls_cipher_id_t;
79
80 typedef enum {
81 MBEDTLS_CIPHER_NONE = 0,
82 MBEDTLS_CIPHER_NULL,
83 MBEDTLS_CIPHER_AES_128_ECB,
84 MBEDTLS_CIPHER_AES_192_ECB,
85 MBEDTLS_CIPHER_AES_256_ECB,
86 MBEDTLS_CIPHER_AES_128_CBC,
87 MBEDTLS_CIPHER_AES_192_CBC,
88 MBEDTLS_CIPHER_AES_256_CBC,
89 MBEDTLS_CIPHER_AES_128_CFB128,
90 MBEDTLS_CIPHER_AES_192_CFB128,
91 MBEDTLS_CIPHER_AES_256_CFB128,
92 MBEDTLS_CIPHER_AES_128_CTR,
93 MBEDTLS_CIPHER_AES_192_CTR,
94 MBEDTLS_CIPHER_AES_256_CTR,
95 MBEDTLS_CIPHER_AES_128_GCM,
96 MBEDTLS_CIPHER_AES_192_GCM,
97 MBEDTLS_CIPHER_AES_256_GCM,
98 MBEDTLS_CIPHER_CAMELLIA_128_ECB,
99 MBEDTLS_CIPHER_CAMELLIA_192_ECB,
100 MBEDTLS_CIPHER_CAMELLIA_256_ECB,
101 MBEDTLS_CIPHER_CAMELLIA_128_CBC,
102 MBEDTLS_CIPHER_CAMELLIA_192_CBC,
103 MBEDTLS_CIPHER_CAMELLIA_256_CBC,
104 MBEDTLS_CIPHER_CAMELLIA_128_CFB128,
105 MBEDTLS_CIPHER_CAMELLIA_192_CFB128,
106 MBEDTLS_CIPHER_CAMELLIA_256_CFB128,
107 MBEDTLS_CIPHER_CAMELLIA_128_CTR,
108 MBEDTLS_CIPHER_CAMELLIA_192_CTR,
109 MBEDTLS_CIPHER_CAMELLIA_256_CTR,
110 MBEDTLS_CIPHER_CAMELLIA_128_GCM,
111 MBEDTLS_CIPHER_CAMELLIA_192_GCM,
112 MBEDTLS_CIPHER_CAMELLIA_256_GCM,
113 MBEDTLS_CIPHER_DES_ECB,
114 MBEDTLS_CIPHER_DES_CBC,
115 MBEDTLS_CIPHER_DES_EDE_ECB,
116 MBEDTLS_CIPHER_DES_EDE_CBC,
117 MBEDTLS_CIPHER_DES_EDE3_ECB,
118 MBEDTLS_CIPHER_DES_EDE3_CBC,
119 MBEDTLS_CIPHER_BLOWFISH_ECB,
120 MBEDTLS_CIPHER_BLOWFISH_CBC,
121 MBEDTLS_CIPHER_BLOWFISH_CFB64,
122 MBEDTLS_CIPHER_BLOWFISH_CTR,
123 MBEDTLS_CIPHER_ARC4_128,
124 MBEDTLS_CIPHER_AES_128_CCM,
125 MBEDTLS_CIPHER_AES_192_CCM,
126 MBEDTLS_CIPHER_AES_256_CCM,
127 MBEDTLS_CIPHER_CAMELLIA_128_CCM,
128 MBEDTLS_CIPHER_CAMELLIA_192_CCM,
129 MBEDTLS_CIPHER_CAMELLIA_256_CCM,
130 } mbedtls_cipher_type_t;
131
132 typedef enum {
133 MBEDTLS_MODE_NONE = 0,
134 MBEDTLS_MODE_ECB,
135 MBEDTLS_MODE_CBC,
136 MBEDTLS_MODE_CFB,
137 MBEDTLS_MODE_OFB, /* Unused! */
138 MBEDTLS_MODE_CTR,
139 MBEDTLS_MODE_GCM,
140 MBEDTLS_MODE_STREAM,
141 MBEDTLS_MODE_CCM,
142 } mbedtls_cipher_mode_t;
143
144 typedef enum {
145 MBEDTLS_PADDING_PKCS7 = 0, /**< PKCS7 padding (default) */
146 MBEDTLS_PADDING_ONE_AND_ZEROS, /**< ISO/IEC 7816-4 padding */
147 MBEDTLS_PADDING_ZEROS_AND_LEN, /**< ANSI X.923 padding */
148 MBEDTLS_PADDING_ZEROS, /**< zero padding (not reversible!) */
149 MBEDTLS_PADDING_NONE, /**< never pad (full blocks only) */
150 } mbedtls_cipher_padding_t;
151
152 typedef enum {
153 MBEDTLS_OPERATION_NONE = -1,
154 MBEDTLS_DECRYPT = 0,
155 MBEDTLS_ENCRYPT,
156 } mbedtls_operation_t;
157
158 enum {
159 /** Undefined key length */
160 MBEDTLS_KEY_LENGTH_NONE = 0,
161 /** Key length, in bits (including parity), for DES keys */
162 MBEDTLS_KEY_LENGTH_DES = 64,
163 /** Key length, in bits (including parity), for DES in two key EDE */
164 MBEDTLS_KEY_LENGTH_DES_EDE = 128,
165 /** Key length, in bits (including parity), for DES in three-key EDE */
166 MBEDTLS_KEY_LENGTH_DES_EDE3 = 192,
167 };
168
169 /** Maximum length of any IV, in bytes */
170 #define MBEDTLS_MAX_IV_LENGTH 16
171 /** Maximum block size of any cipher, in bytes */
172 #define MBEDTLS_MAX_BLOCK_LENGTH 16
173
174 /**
175 * Base cipher information (opaque struct).
176 */
177 typedef struct mbedtls_cipher_base_t mbedtls_cipher_base_t;
178
179 /**
180 * CMAC context (opaque struct).
181 */
182 typedef struct mbedtls_cmac_context_t mbedtls_cmac_context_t;
183
184 /**
185 * Cipher information. Allows cipher functions to be called in a generic way.
186 */
187 typedef struct {
188 /** Full cipher identifier (e.g. MBEDTLS_CIPHER_AES_256_CBC) */
189 mbedtls_cipher_type_t type;
190
191 /** Cipher mode (e.g. MBEDTLS_MODE_CBC) */
192 mbedtls_cipher_mode_t mode;
193
194 /** Cipher key length, in bits (default length for variable sized ciphers)
195 * (Includes parity bits for ciphers like DES) */
196 unsigned int key_bitlen;
197
198 /** Name of the cipher */
199 const char * name;
200
201 /** IV/NONCE size, in bytes.
202 * For cipher that accept many sizes: recommended size */
203 unsigned int iv_size;
204
205 /** Flags for variable IV size, variable key size, etc. */
206 int flags;
207
208 /** block size, in bytes */
209 unsigned int block_size;
210
211 /** Base cipher information and functions */
212 const mbedtls_cipher_base_t *base;
213
214 } mbedtls_cipher_info_t;
215
216 /**
217 * Generic cipher context.
218 */
219 typedef struct {
220 /** Information about the associated cipher */
221 const mbedtls_cipher_info_t *cipher_info;
222
223 /** Key length to use */
224 int key_bitlen;
225
226 /** Operation that the context's key has been initialised for */
227 mbedtls_operation_t operation;
228
229 #if defined(MBEDTLS_CIPHER_MODE_WITH_PADDING)
230 /** Padding functions to use, if relevant for cipher mode */
231 void (*add_padding)( unsigned char *output, size_t olen, size_t data_len );
232 int (*get_padding)( unsigned char *input, size_t ilen, size_t *data_len );
233 #endif
234
235 /** Buffer for data that hasn't been encrypted yet */
236 unsigned char unprocessed_data[MBEDTLS_MAX_BLOCK_LENGTH];
237
238 /** Number of bytes that still need processing */
239 size_t unprocessed_len;
240
241 /** Current IV or NONCE_COUNTER for CTR-mode */
242 unsigned char iv[MBEDTLS_MAX_IV_LENGTH];
243
244 /** IV size in bytes (for ciphers with variable-length IVs) */
245 size_t iv_size;
246
247 /** Cipher-specific context */
248 void *cipher_ctx;
249
250 #if defined(MBEDTLS_CMAC_C)
251 /** CMAC Specific context */
252 mbedtls_cmac_context_t *cmac_ctx;
253 #endif
254 } mbedtls_cipher_context_t;
255
256 /**
257 * \brief Returns the list of ciphers supported by the generic cipher module.
258 *
259 * \return a statically allocated array of ciphers, the last entry
260 * is 0.
261 */
262 const int *mbedtls_cipher_list( void );
263
264 /**
265 * \brief Returns the cipher information structure associated
266 * with the given cipher name.
267 *
268 * \param cipher_name Name of the cipher to search for.
269 *
270 * \return the cipher information structure associated with the
271 * given cipher_name, or NULL if not found.
272 */
273 const mbedtls_cipher_info_t *mbedtls_cipher_info_from_string( const char *cipher_name );
274
275 /**
276 * \brief Returns the cipher information structure associated
277 * with the given cipher type.
278 *
279 * \param cipher_type Type of the cipher to search for.
280 *
281 * \return the cipher information structure associated with the
282 * given cipher_type, or NULL if not found.
283 */
284 const mbedtls_cipher_info_t *mbedtls_cipher_info_from_type( const mbedtls_cipher_type_t cipher_type );
285
286 /**
287 * \brief Returns the cipher information structure associated
288 * with the given cipher id, key size and mode.
289 *
290 * \param cipher_id Id of the cipher to search for
291 * (e.g. MBEDTLS_CIPHER_ID_AES)
292 * \param key_bitlen Length of the key in bits
293 * \param mode Cipher mode (e.g. MBEDTLS_MODE_CBC)
294 *
295 * \return the cipher information structure associated with the
296 * given cipher_type, or NULL if not found.
297 */
298 const mbedtls_cipher_info_t *mbedtls_cipher_info_from_values( const mbedtls_cipher_id_t cipher_id,
299 int key_bitlen,
300 const mbedtls_cipher_mode_t mode );
301
302 /**
303 * \brief Initialize a cipher_context (as NONE)
304 */
305 void mbedtls_cipher_init( mbedtls_cipher_context_t *ctx );
306
307 /**
308 * \brief Free and clear the cipher-specific context of ctx.
309 * Freeing ctx itself remains the responsibility of the
310 * caller.
311 */
312 void mbedtls_cipher_free( mbedtls_cipher_context_t *ctx );
313
314 /**
315 * \brief Initialises and fills the cipher context structure with
316 * the appropriate values.
317 *
318 * \note Currently also clears structure. In future versions you
319 * will be required to call mbedtls_cipher_init() on the structure
320 * first.
321 *
322 * \param ctx context to initialise. May not be NULL.
323 * \param cipher_info cipher to use.
324 *
325 * \return 0 on success,
326 * MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on parameter failure,
327 * MBEDTLS_ERR_CIPHER_ALLOC_FAILED if allocation of the
328 * cipher-specific context failed.
329 */
330 int mbedtls_cipher_setup( mbedtls_cipher_context_t *ctx, const mbedtls_cipher_info_t *cipher_info );
331
332 /**
333 * \brief Returns the block size of the given cipher.
334 *
335 * \param ctx cipher's context. Must have been initialised.
336 *
337 * \return size of the cipher's blocks, or 0 if ctx has not been
338 * initialised.
339 */
mbedtls_cipher_get_block_size(const mbedtls_cipher_context_t * ctx)340 static inline unsigned int mbedtls_cipher_get_block_size( const mbedtls_cipher_context_t *ctx )
341 {
342 if( NULL == ctx || NULL == ctx->cipher_info )
343 return 0;
344
345 return ctx->cipher_info->block_size;
346 }
347
348 /**
349 * \brief Returns the mode of operation for the cipher.
350 * (e.g. MBEDTLS_MODE_CBC)
351 *
352 * \param ctx cipher's context. Must have been initialised.
353 *
354 * \return mode of operation, or MBEDTLS_MODE_NONE if ctx
355 * has not been initialised.
356 */
mbedtls_cipher_get_cipher_mode(const mbedtls_cipher_context_t * ctx)357 static inline mbedtls_cipher_mode_t mbedtls_cipher_get_cipher_mode( const mbedtls_cipher_context_t *ctx )
358 {
359 if( NULL == ctx || NULL == ctx->cipher_info )
360 return MBEDTLS_MODE_NONE;
361
362 return ctx->cipher_info->mode;
363 }
364
365 /**
366 * \brief Returns the size of the cipher's IV/NONCE in bytes.
367 *
368 * \param ctx cipher's context. Must have been initialised.
369 *
370 * \return If IV has not been set yet: (recommended) IV size
371 * (0 for ciphers not using IV/NONCE).
372 * If IV has already been set: actual size.
373 */
mbedtls_cipher_get_iv_size(const mbedtls_cipher_context_t * ctx)374 static inline int mbedtls_cipher_get_iv_size( const mbedtls_cipher_context_t *ctx )
375 {
376 if( NULL == ctx || NULL == ctx->cipher_info )
377 return 0;
378
379 if( ctx->iv_size != 0 )
380 return (int) ctx->iv_size;
381
382 return (int) ctx->cipher_info->iv_size;
383 }
384
385 /**
386 * \brief Returns the type of the given cipher.
387 *
388 * \param ctx cipher's context. Must have been initialised.
389 *
390 * \return type of the cipher, or MBEDTLS_CIPHER_NONE if ctx has
391 * not been initialised.
392 */
mbedtls_cipher_get_type(const mbedtls_cipher_context_t * ctx)393 static inline mbedtls_cipher_type_t mbedtls_cipher_get_type( const mbedtls_cipher_context_t *ctx )
394 {
395 if( NULL == ctx || NULL == ctx->cipher_info )
396 return MBEDTLS_CIPHER_NONE;
397
398 return ctx->cipher_info->type;
399 }
400
401 /**
402 * \brief Returns the name of the given cipher, as a string.
403 *
404 * \param ctx cipher's context. Must have been initialised.
405 *
406 * \return name of the cipher, or NULL if ctx was not initialised.
407 */
mbedtls_cipher_get_name(const mbedtls_cipher_context_t * ctx)408 static inline const char *mbedtls_cipher_get_name( const mbedtls_cipher_context_t *ctx )
409 {
410 if( NULL == ctx || NULL == ctx->cipher_info )
411 return 0;
412
413 return ctx->cipher_info->name;
414 }
415
416 /**
417 * \brief Returns the key length of the cipher.
418 *
419 * \param ctx cipher's context. Must have been initialised.
420 *
421 * \return cipher's key length, in bits, or
422 * MBEDTLS_KEY_LENGTH_NONE if ctx has not been
423 * initialised.
424 */
mbedtls_cipher_get_key_bitlen(const mbedtls_cipher_context_t * ctx)425 static inline int mbedtls_cipher_get_key_bitlen( const mbedtls_cipher_context_t *ctx )
426 {
427 if( NULL == ctx || NULL == ctx->cipher_info )
428 return MBEDTLS_KEY_LENGTH_NONE;
429
430 return (int) ctx->cipher_info->key_bitlen;
431 }
432
433 /**
434 * \brief Returns the operation of the given cipher.
435 *
436 * \param ctx cipher's context. Must have been initialised.
437 *
438 * \return operation (MBEDTLS_ENCRYPT or MBEDTLS_DECRYPT),
439 * or MBEDTLS_OPERATION_NONE if ctx has not been
440 * initialised.
441 */
mbedtls_cipher_get_operation(const mbedtls_cipher_context_t * ctx)442 static inline mbedtls_operation_t mbedtls_cipher_get_operation( const mbedtls_cipher_context_t *ctx )
443 {
444 if( NULL == ctx || NULL == ctx->cipher_info )
445 return MBEDTLS_OPERATION_NONE;
446
447 return ctx->operation;
448 }
449
450 /**
451 * \brief Set the key to use with the given context.
452 *
453 * \param ctx generic cipher context. May not be NULL. Must have been
454 * initialised using cipher_context_from_type or
455 * cipher_context_from_string.
456 * \param key The key to use.
457 * \param key_bitlen key length to use, in bits.
458 * \param operation Operation that the key will be used for, either
459 * MBEDTLS_ENCRYPT or MBEDTLS_DECRYPT.
460 *
461 * \returns 0 on success, MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA if
462 * parameter verification fails or a cipher specific
463 * error code.
464 */
465 int mbedtls_cipher_setkey( mbedtls_cipher_context_t *ctx, const unsigned char *key,
466 int key_bitlen, const mbedtls_operation_t operation );
467
468 #if defined(MBEDTLS_CIPHER_MODE_WITH_PADDING)
469 /**
470 * \brief Set padding mode, for cipher modes that use padding.
471 * (Default: PKCS7 padding.)
472 *
473 * \param ctx generic cipher context
474 * \param mode padding mode
475 *
476 * \returns 0 on success, MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE
477 * if selected padding mode is not supported, or
478 * MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA if the cipher mode
479 * does not support padding.
480 */
481 int mbedtls_cipher_set_padding_mode( mbedtls_cipher_context_t *ctx, mbedtls_cipher_padding_t mode );
482 #endif /* MBEDTLS_CIPHER_MODE_WITH_PADDING */
483
484 /**
485 * \brief Set the initialization vector (IV) or nonce
486 *
487 * \param ctx generic cipher context
488 * \param iv IV to use (or NONCE_COUNTER for CTR-mode ciphers)
489 * \param iv_len IV length for ciphers with variable-size IV;
490 * discarded by ciphers with fixed-size IV.
491 *
492 * \returns 0 on success, or MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA
493 *
494 * \note Some ciphers don't use IVs nor NONCE. For these
495 * ciphers, this function has no effect.
496 */
497 int mbedtls_cipher_set_iv( mbedtls_cipher_context_t *ctx,
498 const unsigned char *iv, size_t iv_len );
499
500 /**
501 * \brief Finish preparation of the given context
502 *
503 * \param ctx generic cipher context
504 *
505 * \returns 0 on success, MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA
506 * if parameter verification fails.
507 */
508 int mbedtls_cipher_reset( mbedtls_cipher_context_t *ctx );
509
510 #if defined(MBEDTLS_GCM_C)
511 /**
512 * \brief Add additional data (for AEAD ciphers).
513 * Currently only supported with GCM.
514 * Must be called exactly once, after mbedtls_cipher_reset().
515 *
516 * \param ctx generic cipher context
517 * \param ad Additional data to use.
518 * \param ad_len Length of ad.
519 *
520 * \return 0 on success, or a specific error code.
521 */
522 int mbedtls_cipher_update_ad( mbedtls_cipher_context_t *ctx,
523 const unsigned char *ad, size_t ad_len );
524 #endif /* MBEDTLS_GCM_C */
525
526 /**
527 * \brief Generic cipher update function. Encrypts/decrypts
528 * using the given cipher context. Writes as many block
529 * size'd blocks of data as possible to output. Any data
530 * that cannot be written immediately will either be added
531 * to the next block, or flushed when cipher_final is
532 * called.
533 * Exception: for MBEDTLS_MODE_ECB, expects single block
534 * in size (e.g. 16 bytes for AES)
535 *
536 * \param ctx generic cipher context
537 * \param input buffer holding the input data
538 * \param ilen length of the input data
539 * \param output buffer for the output data. Should be able to hold at
540 * least ilen + block_size. Cannot be the same buffer as
541 * input!
542 * \param olen length of the output data, will be filled with the
543 * actual number of bytes written.
544 *
545 * \returns 0 on success, MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA if
546 * parameter verification fails,
547 * MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE on an
548 * unsupported mode for a cipher or a cipher specific
549 * error code.
550 *
551 * \note If the underlying cipher is GCM, all calls to this
552 * function, except the last one before mbedtls_cipher_finish(),
553 * must have ilen a multiple of the block size.
554 */
555 int mbedtls_cipher_update( mbedtls_cipher_context_t *ctx, const unsigned char *input,
556 size_t ilen, unsigned char *output, size_t *olen );
557
558 /**
559 * \brief Generic cipher finalisation function. If data still
560 * needs to be flushed from an incomplete block, data
561 * contained within it will be padded with the size of
562 * the last block, and written to the output buffer.
563 *
564 * \param ctx Generic cipher context
565 * \param output buffer to write data to. Needs block_size available.
566 * \param olen length of the data written to the output buffer.
567 *
568 * \returns 0 on success, MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA if
569 * parameter verification fails,
570 * MBEDTLS_ERR_CIPHER_FULL_BLOCK_EXPECTED if decryption
571 * expected a full block but was not provided one,
572 * MBEDTLS_ERR_CIPHER_INVALID_PADDING on invalid padding
573 * while decrypting or a cipher specific error code.
574 */
575 int mbedtls_cipher_finish( mbedtls_cipher_context_t *ctx,
576 unsigned char *output, size_t *olen );
577
578 #if defined(MBEDTLS_GCM_C)
579 /**
580 * \brief Write tag for AEAD ciphers.
581 * Currently only supported with GCM.
582 * Must be called after mbedtls_cipher_finish().
583 *
584 * \param ctx Generic cipher context
585 * \param tag buffer to write the tag
586 * \param tag_len Length of the tag to write
587 *
588 * \return 0 on success, or a specific error code.
589 */
590 int mbedtls_cipher_write_tag( mbedtls_cipher_context_t *ctx,
591 unsigned char *tag, size_t tag_len );
592
593 /**
594 * \brief Check tag for AEAD ciphers.
595 * Currently only supported with GCM.
596 * Must be called after mbedtls_cipher_finish().
597 *
598 * \param ctx Generic cipher context
599 * \param tag Buffer holding the tag
600 * \param tag_len Length of the tag to check
601 *
602 * \return 0 on success, or a specific error code.
603 */
604 int mbedtls_cipher_check_tag( mbedtls_cipher_context_t *ctx,
605 const unsigned char *tag, size_t tag_len );
606 #endif /* MBEDTLS_GCM_C */
607
608 /**
609 * \brief Generic all-in-one encryption/decryption
610 * (for all ciphers except AEAD constructs).
611 *
612 * \param ctx generic cipher context
613 * \param iv IV to use (or NONCE_COUNTER for CTR-mode ciphers)
614 * \param iv_len IV length for ciphers with variable-size IV;
615 * discarded by ciphers with fixed-size IV.
616 * \param input buffer holding the input data
617 * \param ilen length of the input data
618 * \param output buffer for the output data. Should be able to hold at
619 * least ilen + block_size. Cannot be the same buffer as
620 * input!
621 * \param olen length of the output data, will be filled with the
622 * actual number of bytes written.
623 *
624 * \note Some ciphers don't use IVs nor NONCE. For these
625 * ciphers, use iv = NULL and iv_len = 0.
626 *
627 * \returns 0 on success, or
628 * MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA, or
629 * MBEDTLS_ERR_CIPHER_FULL_BLOCK_EXPECTED if decryption
630 * expected a full block but was not provided one, or
631 * MBEDTLS_ERR_CIPHER_INVALID_PADDING on invalid padding
632 * while decrypting, or
633 * a cipher specific error code.
634 */
635 int mbedtls_cipher_crypt( mbedtls_cipher_context_t *ctx,
636 const unsigned char *iv, size_t iv_len,
637 const unsigned char *input, size_t ilen,
638 unsigned char *output, size_t *olen );
639
640 #if defined(MBEDTLS_CIPHER_MODE_AEAD)
641 /**
642 * \brief Generic autenticated encryption (AEAD ciphers).
643 *
644 * \param ctx generic cipher context
645 * \param iv IV to use (or NONCE_COUNTER for CTR-mode ciphers)
646 * \param iv_len IV length for ciphers with variable-size IV;
647 * discarded by ciphers with fixed-size IV.
648 * \param ad Additional data to authenticate.
649 * \param ad_len Length of ad.
650 * \param input buffer holding the input data
651 * \param ilen length of the input data
652 * \param output buffer for the output data.
653 * Should be able to hold at least ilen.
654 * \param olen length of the output data, will be filled with the
655 * actual number of bytes written.
656 * \param tag buffer for the authentication tag
657 * \param tag_len desired tag length
658 *
659 * \returns 0 on success, or
660 * MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA, or
661 * a cipher specific error code.
662 */
663 int mbedtls_cipher_auth_encrypt( mbedtls_cipher_context_t *ctx,
664 const unsigned char *iv, size_t iv_len,
665 const unsigned char *ad, size_t ad_len,
666 const unsigned char *input, size_t ilen,
667 unsigned char *output, size_t *olen,
668 unsigned char *tag, size_t tag_len );
669
670 /**
671 * \brief Generic autenticated decryption (AEAD ciphers).
672 *
673 * \param ctx generic cipher context
674 * \param iv IV to use (or NONCE_COUNTER for CTR-mode ciphers)
675 * \param iv_len IV length for ciphers with variable-size IV;
676 * discarded by ciphers with fixed-size IV.
677 * \param ad Additional data to be authenticated.
678 * \param ad_len Length of ad.
679 * \param input buffer holding the input data
680 * \param ilen length of the input data
681 * \param output buffer for the output data.
682 * Should be able to hold at least ilen.
683 * \param olen length of the output data, will be filled with the
684 * actual number of bytes written.
685 * \param tag buffer holding the authentication tag
686 * \param tag_len length of the authentication tag
687 *
688 * \returns 0 on success, or
689 * MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA, or
690 * MBEDTLS_ERR_CIPHER_AUTH_FAILED if data isn't authentic,
691 * or a cipher specific error code.
692 *
693 * \note If the data is not authentic, then the output buffer
694 * is zeroed out to prevent the unauthentic plaintext to
695 * be used by mistake, making this interface safer.
696 */
697 int mbedtls_cipher_auth_decrypt( mbedtls_cipher_context_t *ctx,
698 const unsigned char *iv, size_t iv_len,
699 const unsigned char *ad, size_t ad_len,
700 const unsigned char *input, size_t ilen,
701 unsigned char *output, size_t *olen,
702 const unsigned char *tag, size_t tag_len );
703 #endif /* MBEDTLS_CIPHER_MODE_AEAD */
704
705 #ifdef __cplusplus
706 }
707 #endif
708
709 #endif /* MBEDTLS_CIPHER_H */
710
