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 (C) 2006-2018, Arm Limited (or its affiliates), All Rights Reserved
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 * This file is part of Mbed TLS (https://tls.mbed.org)
27 */
28
29 #ifndef MBEDTLS_CIPHER_H
30 #define MBEDTLS_CIPHER_H
31
32 #if !defined(MBEDTLS_CONFIG_FILE)
33 #include "config.h"
34 #else
35 #include MBEDTLS_CONFIG_FILE
36 #endif
37
38 #include <stddef.h>
39 #include "mbedtls/platform_util.h"
40
41 #if defined(MBEDTLS_GCM_C) || defined(MBEDTLS_CCM_C) || defined(MBEDTLS_CHACHAPOLY_C)
42 #define MBEDTLS_CIPHER_MODE_AEAD
43 #endif
44
45 #if defined(MBEDTLS_CIPHER_MODE_CBC)
46 #define MBEDTLS_CIPHER_MODE_WITH_PADDING
47 #endif
48
49 #if defined(MBEDTLS_ARC4_C) || defined(MBEDTLS_CIPHER_NULL_CIPHER) || \
50 defined(MBEDTLS_CHACHA20_C)
51 #define MBEDTLS_CIPHER_MODE_STREAM
52 #endif
53
54 #if ( defined(__ARMCC_VERSION) || defined(_MSC_VER) ) && \
55 !defined(inline) && !defined(__cplusplus)
56 #define inline __inline
57 #endif
58
59 #define MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE -0x6080 /**< The selected feature is not available. */
60 #define MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA -0x6100 /**< Bad input parameters. */
61 #define MBEDTLS_ERR_CIPHER_ALLOC_FAILED -0x6180 /**< Failed to allocate memory. */
62 #define MBEDTLS_ERR_CIPHER_INVALID_PADDING -0x6200 /**< Input data contains invalid padding and is rejected. */
63 #define MBEDTLS_ERR_CIPHER_FULL_BLOCK_EXPECTED -0x6280 /**< Decryption of block requires a full block. */
64 #define MBEDTLS_ERR_CIPHER_AUTH_FAILED -0x6300 /**< Authentication failed (for AEAD modes). */
65 #define MBEDTLS_ERR_CIPHER_INVALID_CONTEXT -0x6380 /**< The context is invalid. For example, because it was freed. */
66
67 /* MBEDTLS_ERR_CIPHER_HW_ACCEL_FAILED is deprecated and should not be used. */
68 #define MBEDTLS_ERR_CIPHER_HW_ACCEL_FAILED -0x6400 /**< Cipher hardware accelerator failed. */
69
70 #define MBEDTLS_CIPHER_VARIABLE_IV_LEN 0x01 /**< Cipher accepts IVs of variable length. */
71 #define MBEDTLS_CIPHER_VARIABLE_KEY_LEN 0x02 /**< Cipher accepts keys of variable length. */
72
73 #ifdef __cplusplus
74 extern "C" {
75 #endif
76
77 /**
78 * \brief Supported cipher types.
79 *
80 * \warning RC4 and DES are considered weak ciphers and their use
81 * constitutes a security risk. Arm recommends considering stronger
82 * ciphers instead.
83 */
84 typedef enum {
85 MBEDTLS_CIPHER_ID_NONE = 0, /**< Placeholder to mark the end of cipher ID lists. */
86 MBEDTLS_CIPHER_ID_NULL, /**< The identity cipher, treated as a stream cipher. */
87 MBEDTLS_CIPHER_ID_AES, /**< The AES cipher. */
88 MBEDTLS_CIPHER_ID_DES, /**< The DES cipher. */
89 MBEDTLS_CIPHER_ID_3DES, /**< The Triple DES cipher. */
90 MBEDTLS_CIPHER_ID_CAMELLIA, /**< The Camellia cipher. */
91 MBEDTLS_CIPHER_ID_BLOWFISH, /**< The Blowfish cipher. */
92 MBEDTLS_CIPHER_ID_ARC4, /**< The RC4 cipher. */
93 MBEDTLS_CIPHER_ID_ARIA, /**< The Aria cipher. */
94 MBEDTLS_CIPHER_ID_CHACHA20, /**< The ChaCha20 cipher. */
95 } mbedtls_cipher_id_t;
96
97 /**
98 * \brief Supported {cipher type, cipher mode} pairs.
99 *
100 * \warning RC4 and DES are considered weak ciphers and their use
101 * constitutes a security risk. Arm recommends considering stronger
102 * ciphers instead.
103 */
104 typedef enum {
105 MBEDTLS_CIPHER_NONE = 0, /**< Placeholder to mark the end of cipher-pair lists. */
106 MBEDTLS_CIPHER_NULL, /**< The identity stream cipher. */
107 MBEDTLS_CIPHER_AES_128_ECB, /**< AES cipher with 128-bit ECB mode. */
108 MBEDTLS_CIPHER_AES_192_ECB, /**< AES cipher with 192-bit ECB mode. */
109 MBEDTLS_CIPHER_AES_256_ECB, /**< AES cipher with 256-bit ECB mode. */
110 MBEDTLS_CIPHER_AES_128_CBC, /**< AES cipher with 128-bit CBC mode. */
111 MBEDTLS_CIPHER_AES_192_CBC, /**< AES cipher with 192-bit CBC mode. */
112 MBEDTLS_CIPHER_AES_256_CBC, /**< AES cipher with 256-bit CBC mode. */
113 MBEDTLS_CIPHER_AES_128_CFB128, /**< AES cipher with 128-bit CFB128 mode. */
114 MBEDTLS_CIPHER_AES_192_CFB128, /**< AES cipher with 192-bit CFB128 mode. */
115 MBEDTLS_CIPHER_AES_256_CFB128, /**< AES cipher with 256-bit CFB128 mode. */
116 MBEDTLS_CIPHER_AES_128_CTR, /**< AES cipher with 128-bit CTR mode. */
117 MBEDTLS_CIPHER_AES_192_CTR, /**< AES cipher with 192-bit CTR mode. */
118 MBEDTLS_CIPHER_AES_256_CTR, /**< AES cipher with 256-bit CTR mode. */
119 MBEDTLS_CIPHER_AES_128_GCM, /**< AES cipher with 128-bit GCM mode. */
120 MBEDTLS_CIPHER_AES_192_GCM, /**< AES cipher with 192-bit GCM mode. */
121 MBEDTLS_CIPHER_AES_256_GCM, /**< AES cipher with 256-bit GCM mode. */
122 MBEDTLS_CIPHER_CAMELLIA_128_ECB, /**< Camellia cipher with 128-bit ECB mode. */
123 MBEDTLS_CIPHER_CAMELLIA_192_ECB, /**< Camellia cipher with 192-bit ECB mode. */
124 MBEDTLS_CIPHER_CAMELLIA_256_ECB, /**< Camellia cipher with 256-bit ECB mode. */
125 MBEDTLS_CIPHER_CAMELLIA_128_CBC, /**< Camellia cipher with 128-bit CBC mode. */
126 MBEDTLS_CIPHER_CAMELLIA_192_CBC, /**< Camellia cipher with 192-bit CBC mode. */
127 MBEDTLS_CIPHER_CAMELLIA_256_CBC, /**< Camellia cipher with 256-bit CBC mode. */
128 MBEDTLS_CIPHER_CAMELLIA_128_CFB128, /**< Camellia cipher with 128-bit CFB128 mode. */
129 MBEDTLS_CIPHER_CAMELLIA_192_CFB128, /**< Camellia cipher with 192-bit CFB128 mode. */
130 MBEDTLS_CIPHER_CAMELLIA_256_CFB128, /**< Camellia cipher with 256-bit CFB128 mode. */
131 MBEDTLS_CIPHER_CAMELLIA_128_CTR, /**< Camellia cipher with 128-bit CTR mode. */
132 MBEDTLS_CIPHER_CAMELLIA_192_CTR, /**< Camellia cipher with 192-bit CTR mode. */
133 MBEDTLS_CIPHER_CAMELLIA_256_CTR, /**< Camellia cipher with 256-bit CTR mode. */
134 MBEDTLS_CIPHER_CAMELLIA_128_GCM, /**< Camellia cipher with 128-bit GCM mode. */
135 MBEDTLS_CIPHER_CAMELLIA_192_GCM, /**< Camellia cipher with 192-bit GCM mode. */
136 MBEDTLS_CIPHER_CAMELLIA_256_GCM, /**< Camellia cipher with 256-bit GCM mode. */
137 MBEDTLS_CIPHER_DES_ECB, /**< DES cipher with ECB mode. */
138 MBEDTLS_CIPHER_DES_CBC, /**< DES cipher with CBC mode. */
139 MBEDTLS_CIPHER_DES_EDE_ECB, /**< DES cipher with EDE ECB mode. */
140 MBEDTLS_CIPHER_DES_EDE_CBC, /**< DES cipher with EDE CBC mode. */
141 MBEDTLS_CIPHER_DES_EDE3_ECB, /**< DES cipher with EDE3 ECB mode. */
142 MBEDTLS_CIPHER_DES_EDE3_CBC, /**< DES cipher with EDE3 CBC mode. */
143 MBEDTLS_CIPHER_BLOWFISH_ECB, /**< Blowfish cipher with ECB mode. */
144 MBEDTLS_CIPHER_BLOWFISH_CBC, /**< Blowfish cipher with CBC mode. */
145 MBEDTLS_CIPHER_BLOWFISH_CFB64, /**< Blowfish cipher with CFB64 mode. */
146 MBEDTLS_CIPHER_BLOWFISH_CTR, /**< Blowfish cipher with CTR mode. */
147 MBEDTLS_CIPHER_ARC4_128, /**< RC4 cipher with 128-bit mode. */
148 MBEDTLS_CIPHER_AES_128_CCM, /**< AES cipher with 128-bit CCM mode. */
149 MBEDTLS_CIPHER_AES_192_CCM, /**< AES cipher with 192-bit CCM mode. */
150 MBEDTLS_CIPHER_AES_256_CCM, /**< AES cipher with 256-bit CCM mode. */
151 MBEDTLS_CIPHER_CAMELLIA_128_CCM, /**< Camellia cipher with 128-bit CCM mode. */
152 MBEDTLS_CIPHER_CAMELLIA_192_CCM, /**< Camellia cipher with 192-bit CCM mode. */
153 MBEDTLS_CIPHER_CAMELLIA_256_CCM, /**< Camellia cipher with 256-bit CCM mode. */
154 MBEDTLS_CIPHER_ARIA_128_ECB, /**< Aria cipher with 128-bit key and ECB mode. */
155 MBEDTLS_CIPHER_ARIA_192_ECB, /**< Aria cipher with 192-bit key and ECB mode. */
156 MBEDTLS_CIPHER_ARIA_256_ECB, /**< Aria cipher with 256-bit key and ECB mode. */
157 MBEDTLS_CIPHER_ARIA_128_CBC, /**< Aria cipher with 128-bit key and CBC mode. */
158 MBEDTLS_CIPHER_ARIA_192_CBC, /**< Aria cipher with 192-bit key and CBC mode. */
159 MBEDTLS_CIPHER_ARIA_256_CBC, /**< Aria cipher with 256-bit key and CBC mode. */
160 MBEDTLS_CIPHER_ARIA_128_CFB128, /**< Aria cipher with 128-bit key and CFB-128 mode. */
161 MBEDTLS_CIPHER_ARIA_192_CFB128, /**< Aria cipher with 192-bit key and CFB-128 mode. */
162 MBEDTLS_CIPHER_ARIA_256_CFB128, /**< Aria cipher with 256-bit key and CFB-128 mode. */
163 MBEDTLS_CIPHER_ARIA_128_CTR, /**< Aria cipher with 128-bit key and CTR mode. */
164 MBEDTLS_CIPHER_ARIA_192_CTR, /**< Aria cipher with 192-bit key and CTR mode. */
165 MBEDTLS_CIPHER_ARIA_256_CTR, /**< Aria cipher with 256-bit key and CTR mode. */
166 MBEDTLS_CIPHER_ARIA_128_GCM, /**< Aria cipher with 128-bit key and GCM mode. */
167 MBEDTLS_CIPHER_ARIA_192_GCM, /**< Aria cipher with 192-bit key and GCM mode. */
168 MBEDTLS_CIPHER_ARIA_256_GCM, /**< Aria cipher with 256-bit key and GCM mode. */
169 MBEDTLS_CIPHER_ARIA_128_CCM, /**< Aria cipher with 128-bit key and CCM mode. */
170 MBEDTLS_CIPHER_ARIA_192_CCM, /**< Aria cipher with 192-bit key and CCM mode. */
171 MBEDTLS_CIPHER_ARIA_256_CCM, /**< Aria cipher with 256-bit key and CCM mode. */
172 MBEDTLS_CIPHER_AES_128_OFB, /**< AES 128-bit cipher in OFB mode. */
173 MBEDTLS_CIPHER_AES_192_OFB, /**< AES 192-bit cipher in OFB mode. */
174 MBEDTLS_CIPHER_AES_256_OFB, /**< AES 256-bit cipher in OFB mode. */
175 MBEDTLS_CIPHER_AES_128_XTS, /**< AES 128-bit cipher in XTS block mode. */
176 MBEDTLS_CIPHER_AES_256_XTS, /**< AES 256-bit cipher in XTS block mode. */
177 MBEDTLS_CIPHER_CHACHA20, /**< ChaCha20 stream cipher. */
178 MBEDTLS_CIPHER_CHACHA20_POLY1305, /**< ChaCha20-Poly1305 AEAD cipher. */
179 } mbedtls_cipher_type_t;
180
181 /** Supported cipher modes. */
182 typedef enum {
183 MBEDTLS_MODE_NONE = 0, /**< None. */
184 MBEDTLS_MODE_ECB, /**< The ECB cipher mode. */
185 MBEDTLS_MODE_CBC, /**< The CBC cipher mode. */
186 MBEDTLS_MODE_CFB, /**< The CFB cipher mode. */
187 MBEDTLS_MODE_OFB, /**< The OFB cipher mode. */
188 MBEDTLS_MODE_CTR, /**< The CTR cipher mode. */
189 MBEDTLS_MODE_GCM, /**< The GCM cipher mode. */
190 MBEDTLS_MODE_STREAM, /**< The stream cipher mode. */
191 MBEDTLS_MODE_CCM, /**< The CCM cipher mode. */
192 MBEDTLS_MODE_XTS, /**< The XTS cipher mode. */
193 MBEDTLS_MODE_CHACHAPOLY, /**< The ChaCha-Poly cipher mode. */
194 } mbedtls_cipher_mode_t;
195
196 /** Supported cipher padding types. */
197 typedef enum {
198 MBEDTLS_PADDING_PKCS7 = 0, /**< PKCS7 padding (default). */
199 MBEDTLS_PADDING_ONE_AND_ZEROS, /**< ISO/IEC 7816-4 padding. */
200 MBEDTLS_PADDING_ZEROS_AND_LEN, /**< ANSI X.923 padding. */
201 MBEDTLS_PADDING_ZEROS, /**< Zero padding (not reversible). */
202 MBEDTLS_PADDING_NONE, /**< Never pad (full blocks only). */
203 } mbedtls_cipher_padding_t;
204
205 /** Type of operation. */
206 typedef enum {
207 MBEDTLS_OPERATION_NONE = -1,
208 MBEDTLS_DECRYPT = 0,
209 MBEDTLS_ENCRYPT,
210 } mbedtls_operation_t;
211
212 enum {
213 /** Undefined key length. */
214 MBEDTLS_KEY_LENGTH_NONE = 0,
215 /** Key length, in bits (including parity), for DES keys. */
216 MBEDTLS_KEY_LENGTH_DES = 64,
217 /** Key length in bits, including parity, for DES in two-key EDE. */
218 MBEDTLS_KEY_LENGTH_DES_EDE = 128,
219 /** Key length in bits, including parity, for DES in three-key EDE. */
220 MBEDTLS_KEY_LENGTH_DES_EDE3 = 192,
221 };
222
223 /** Maximum length of any IV, in Bytes. */
224 #define MBEDTLS_MAX_IV_LENGTH 16
225 /** Maximum block size of any cipher, in Bytes. */
226 #define MBEDTLS_MAX_BLOCK_LENGTH 16
227
228 /**
229 * Base cipher information (opaque struct).
230 */
231 typedef struct mbedtls_cipher_base_t mbedtls_cipher_base_t;
232
233 /**
234 * CMAC context (opaque struct).
235 */
236 typedef struct mbedtls_cmac_context_t mbedtls_cmac_context_t;
237
238 /**
239 * Cipher information. Allows calling cipher functions
240 * in a generic way.
241 */
242 typedef struct mbedtls_cipher_info_t
243 {
244 /** Full cipher identifier. For example,
245 * MBEDTLS_CIPHER_AES_256_CBC.
246 */
247 mbedtls_cipher_type_t type;
248
249 /** The cipher mode. For example, MBEDTLS_MODE_CBC. */
250 mbedtls_cipher_mode_t mode;
251
252 /** The cipher key length, in bits. This is the
253 * default length for variable sized ciphers.
254 * Includes parity bits for ciphers like DES.
255 */
256 unsigned int key_bitlen;
257
258 /** Name of the cipher. */
259 const char * name;
260
261 /** IV or nonce size, in Bytes.
262 * For ciphers that accept variable IV sizes,
263 * this is the recommended size.
264 */
265 unsigned int iv_size;
266
267 /** Bitflag comprised of MBEDTLS_CIPHER_VARIABLE_IV_LEN and
268 * MBEDTLS_CIPHER_VARIABLE_KEY_LEN indicating whether the
269 * cipher supports variable IV or variable key sizes, respectively.
270 */
271 int flags;
272
273 /** The block size, in Bytes. */
274 unsigned int block_size;
275
276 /** Struct for base cipher information and functions. */
277 const mbedtls_cipher_base_t *base;
278
279 } mbedtls_cipher_info_t;
280
281 /**
282 * Generic cipher context.
283 */
284 typedef struct mbedtls_cipher_context_t
285 {
286 /** Information about the associated cipher. */
287 const mbedtls_cipher_info_t *cipher_info;
288
289 /** Key length to use. */
290 int key_bitlen;
291
292 /** Operation that the key of the context has been
293 * initialized for.
294 */
295 mbedtls_operation_t operation;
296
297 #if defined(MBEDTLS_CIPHER_MODE_WITH_PADDING)
298 /** Padding functions to use, if relevant for
299 * the specific cipher mode.
300 */
301 void (*add_padding)( unsigned char *output, size_t olen, size_t data_len );
302 int (*get_padding)( unsigned char *input, size_t ilen, size_t *data_len );
303 #endif
304
305 /** Buffer for input that has not been processed yet. */
306 unsigned char unprocessed_data[MBEDTLS_MAX_BLOCK_LENGTH];
307
308 /** Number of Bytes that have not been processed yet. */
309 size_t unprocessed_len;
310
311 /** Current IV or NONCE_COUNTER for CTR-mode, data unit (or sector) number
312 * for XTS-mode. */
313 unsigned char iv[MBEDTLS_MAX_IV_LENGTH];
314
315 /** IV size in Bytes, for ciphers with variable-length IVs. */
316 size_t iv_size;
317
318 /** The cipher-specific context. */
319 void *cipher_ctx;
320
321 #if defined(MBEDTLS_CMAC_C)
322 /** CMAC-specific context. */
323 mbedtls_cmac_context_t *cmac_ctx;
324 #endif
325 } mbedtls_cipher_context_t;
326
327 /**
328 * \brief This function retrieves the list of ciphers supported by the generic
329 * cipher module.
330 *
331 * \return A statically-allocated array of ciphers. The last entry
332 * is zero.
333 */
334 const int *mbedtls_cipher_list( void );
335
336 /**
337 * \brief This function retrieves the cipher-information
338 * structure associated with the given cipher name.
339 *
340 * \param cipher_name Name of the cipher to search for. This must not be
341 * \c NULL.
342 *
343 * \return The cipher information structure associated with the
344 * given \p cipher_name.
345 * \return \c NULL if the associated cipher information is not found.
346 */
347 const mbedtls_cipher_info_t *mbedtls_cipher_info_from_string( const char *cipher_name );
348
349 /**
350 * \brief This function retrieves the cipher-information
351 * structure associated with the given cipher type.
352 *
353 * \param cipher_type Type of the cipher to search for.
354 *
355 * \return The cipher information structure associated with the
356 * given \p cipher_type.
357 * \return \c NULL if the associated cipher information is not found.
358 */
359 const mbedtls_cipher_info_t *mbedtls_cipher_info_from_type( const mbedtls_cipher_type_t cipher_type );
360
361 /**
362 * \brief This function retrieves the cipher-information
363 * structure associated with the given cipher ID,
364 * key size and mode.
365 *
366 * \param cipher_id The ID of the cipher to search for. For example,
367 * #MBEDTLS_CIPHER_ID_AES.
368 * \param key_bitlen The length of the key in bits.
369 * \param mode The cipher mode. For example, #MBEDTLS_MODE_CBC.
370 *
371 * \return The cipher information structure associated with the
372 * given \p cipher_id.
373 * \return \c NULL if the associated cipher information is not found.
374 */
375 const mbedtls_cipher_info_t *mbedtls_cipher_info_from_values( const mbedtls_cipher_id_t cipher_id,
376 int key_bitlen,
377 const mbedtls_cipher_mode_t mode );
378
379 /**
380 * \brief This function initializes a \p cipher_context as NONE.
381 *
382 * \param ctx The context to be initialized. This must not be \c NULL.
383 */
384 void mbedtls_cipher_init( mbedtls_cipher_context_t *ctx );
385
386 /**
387 * \brief This function frees and clears the cipher-specific
388 * context of \p ctx. Freeing \p ctx itself remains the
389 * responsibility of the caller.
390 *
391 * \param ctx The context to be freed. If this is \c NULL, the
392 * function has no effect, otherwise this must point to an
393 * initialized context.
394 */
395 void mbedtls_cipher_free( mbedtls_cipher_context_t *ctx );
396
397
398 /**
399 * \brief This function initializes and fills the cipher-context
400 * structure with the appropriate values. It also clears
401 * the structure.
402 *
403 * \param ctx The context to initialize. This must be initialized.
404 * \param cipher_info The cipher to use.
405 *
406 * \return \c 0 on success.
407 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
408 * parameter-verification failure.
409 * \return #MBEDTLS_ERR_CIPHER_ALLOC_FAILED if allocation of the
410 * cipher-specific context fails.
411 *
412 * \internal Currently, the function also clears the structure.
413 * In future versions, the caller will be required to call
414 * mbedtls_cipher_init() on the structure first.
415 */
416 int mbedtls_cipher_setup( mbedtls_cipher_context_t *ctx,
417 const mbedtls_cipher_info_t *cipher_info );
418
419 /**
420 * \brief This function returns the block size of the given cipher.
421 *
422 * \param ctx The context of the cipher. This must be initialized.
423 *
424 * \return The block size of the underlying cipher.
425 * \return \c 0 if \p ctx has not been initialized.
426 */
mbedtls_cipher_get_block_size(const mbedtls_cipher_context_t * ctx)427 static inline unsigned int mbedtls_cipher_get_block_size(
428 const mbedtls_cipher_context_t *ctx )
429 {
430 MBEDTLS_INTERNAL_VALIDATE_RET( ctx != NULL, 0 );
431 if( ctx->cipher_info == NULL )
432 return 0;
433
434 return ctx->cipher_info->block_size;
435 }
436
437 /**
438 * \brief This function returns the mode of operation for
439 * the cipher. For example, MBEDTLS_MODE_CBC.
440 *
441 * \param ctx The context of the cipher. This must be initialized.
442 *
443 * \return The mode of operation.
444 * \return #MBEDTLS_MODE_NONE if \p ctx has not been initialized.
445 */
mbedtls_cipher_get_cipher_mode(const mbedtls_cipher_context_t * ctx)446 static inline mbedtls_cipher_mode_t mbedtls_cipher_get_cipher_mode(
447 const mbedtls_cipher_context_t *ctx )
448 {
449 MBEDTLS_INTERNAL_VALIDATE_RET( ctx != NULL, MBEDTLS_MODE_NONE );
450 if( ctx->cipher_info == NULL )
451 return MBEDTLS_MODE_NONE;
452
453 return ctx->cipher_info->mode;
454 }
455
456 /**
457 * \brief This function returns the size of the IV or nonce
458 * of the cipher, in Bytes.
459 *
460 * \param ctx The context of the cipher. This must be initialized.
461 *
462 * \return The recommended IV size if no IV has been set.
463 * \return \c 0 for ciphers not using an IV or a nonce.
464 * \return The actual size if an IV has been set.
465 */
mbedtls_cipher_get_iv_size(const mbedtls_cipher_context_t * ctx)466 static inline int mbedtls_cipher_get_iv_size(
467 const mbedtls_cipher_context_t *ctx )
468 {
469 MBEDTLS_INTERNAL_VALIDATE_RET( ctx != NULL, 0 );
470 if( ctx->cipher_info == NULL )
471 return 0;
472
473 if( ctx->iv_size != 0 )
474 return (int) ctx->iv_size;
475
476 return (int) ctx->cipher_info->iv_size;
477 }
478
479 /**
480 * \brief This function returns the type of the given cipher.
481 *
482 * \param ctx The context of the cipher. This must be initialized.
483 *
484 * \return The type of the cipher.
485 * \return #MBEDTLS_CIPHER_NONE if \p ctx has not been initialized.
486 */
mbedtls_cipher_get_type(const mbedtls_cipher_context_t * ctx)487 static inline mbedtls_cipher_type_t mbedtls_cipher_get_type(
488 const mbedtls_cipher_context_t *ctx )
489 {
490 MBEDTLS_INTERNAL_VALIDATE_RET(
491 ctx != NULL, MBEDTLS_CIPHER_NONE );
492 if( ctx->cipher_info == NULL )
493 return MBEDTLS_CIPHER_NONE;
494
495 return ctx->cipher_info->type;
496 }
497
498 /**
499 * \brief This function returns the name of the given cipher
500 * as a string.
501 *
502 * \param ctx The context of the cipher. This must be initialized.
503 *
504 * \return The name of the cipher.
505 * \return NULL if \p ctx has not been not initialized.
506 */
mbedtls_cipher_get_name(const mbedtls_cipher_context_t * ctx)507 static inline const char *mbedtls_cipher_get_name(
508 const mbedtls_cipher_context_t *ctx )
509 {
510 MBEDTLS_INTERNAL_VALIDATE_RET( ctx != NULL, 0 );
511 if( ctx->cipher_info == NULL )
512 return 0;
513
514 return ctx->cipher_info->name;
515 }
516
517 /**
518 * \brief This function returns the key length of the cipher.
519 *
520 * \param ctx The context of the cipher. This must be initialized.
521 *
522 * \return The key length of the cipher in bits.
523 * \return #MBEDTLS_KEY_LENGTH_NONE if ctx \p has not been
524 * initialized.
525 */
mbedtls_cipher_get_key_bitlen(const mbedtls_cipher_context_t * ctx)526 static inline int mbedtls_cipher_get_key_bitlen(
527 const mbedtls_cipher_context_t *ctx )
528 {
529 MBEDTLS_INTERNAL_VALIDATE_RET(
530 ctx != NULL, MBEDTLS_KEY_LENGTH_NONE );
531 if( ctx->cipher_info == NULL )
532 return MBEDTLS_KEY_LENGTH_NONE;
533
534 return (int) ctx->cipher_info->key_bitlen;
535 }
536
537 /**
538 * \brief This function returns the operation of the given cipher.
539 *
540 * \param ctx The context of the cipher. This must be initialized.
541 *
542 * \return The type of operation: #MBEDTLS_ENCRYPT or #MBEDTLS_DECRYPT.
543 * \return #MBEDTLS_OPERATION_NONE if \p ctx has not been initialized.
544 */
mbedtls_cipher_get_operation(const mbedtls_cipher_context_t * ctx)545 static inline mbedtls_operation_t mbedtls_cipher_get_operation(
546 const mbedtls_cipher_context_t *ctx )
547 {
548 MBEDTLS_INTERNAL_VALIDATE_RET(
549 ctx != NULL, MBEDTLS_OPERATION_NONE );
550 if( ctx->cipher_info == NULL )
551 return MBEDTLS_OPERATION_NONE;
552
553 return ctx->operation;
554 }
555
556 /**
557 * \brief This function sets the key to use with the given context.
558 *
559 * \param ctx The generic cipher context. This must be initialized and
560 * bound to a cipher information structure.
561 * \param key The key to use. This must be a readable buffer of at
562 * least \p key_bitlen Bits.
563 * \param key_bitlen The key length to use, in Bits.
564 * \param operation The operation that the key will be used for:
565 * #MBEDTLS_ENCRYPT or #MBEDTLS_DECRYPT.
566 *
567 * \return \c 0 on success.
568 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
569 * parameter-verification failure.
570 * \return A cipher-specific error code on failure.
571 */
572 int mbedtls_cipher_setkey( mbedtls_cipher_context_t *ctx,
573 const unsigned char *key,
574 int key_bitlen,
575 const mbedtls_operation_t operation );
576
577 #if defined(MBEDTLS_CIPHER_MODE_WITH_PADDING)
578 /**
579 * \brief This function sets the padding mode, for cipher modes
580 * that use padding.
581 *
582 * The default passing mode is PKCS7 padding.
583 *
584 * \param ctx The generic cipher context. This must be initialized and
585 * bound to a cipher information structure.
586 * \param mode The padding mode.
587 *
588 * \return \c 0 on success.
589 * \return #MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE
590 * if the selected padding mode is not supported.
591 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA if the cipher mode
592 * does not support padding.
593 */
594 int mbedtls_cipher_set_padding_mode( mbedtls_cipher_context_t *ctx,
595 mbedtls_cipher_padding_t mode );
596 #endif /* MBEDTLS_CIPHER_MODE_WITH_PADDING */
597
598 /**
599 * \brief This function sets the initialization vector (IV)
600 * or nonce.
601 *
602 * \note Some ciphers do not use IVs nor nonce. For these
603 * ciphers, this function has no effect.
604 *
605 * \param ctx The generic cipher context. This must be initialized and
606 * bound to a cipher information structure.
607 * \param iv The IV to use, or NONCE_COUNTER for CTR-mode ciphers. This
608 * must be a readable buffer of at least \p iv_len Bytes.
609 * \param iv_len The IV length for ciphers with variable-size IV.
610 * This parameter is discarded by ciphers with fixed-size IV.
611 *
612 * \return \c 0 on success.
613 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
614 * parameter-verification failure.
615 */
616 int mbedtls_cipher_set_iv( mbedtls_cipher_context_t *ctx,
617 const unsigned char *iv,
618 size_t iv_len );
619
620 /**
621 * \brief This function resets the cipher state.
622 *
623 * \param ctx The generic cipher context. This must be initialized.
624 *
625 * \return \c 0 on success.
626 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
627 * parameter-verification failure.
628 */
629 int mbedtls_cipher_reset( mbedtls_cipher_context_t *ctx );
630
631 #if defined(MBEDTLS_GCM_C) || defined(MBEDTLS_CHACHAPOLY_C)
632 /**
633 * \brief This function adds additional data for AEAD ciphers.
634 * Currently supported with GCM and ChaCha20+Poly1305.
635 * This must be called exactly once, after
636 * mbedtls_cipher_reset().
637 *
638 * \param ctx The generic cipher context. This must be initialized.
639 * \param ad The additional data to use. This must be a readable
640 * buffer of at least \p ad_len Bytes.
641 * \param ad_len the Length of \p ad Bytes.
642 *
643 * \return \c 0 on success.
644 * \return A specific error code on failure.
645 */
646 int mbedtls_cipher_update_ad( mbedtls_cipher_context_t *ctx,
647 const unsigned char *ad, size_t ad_len );
648 #endif /* MBEDTLS_GCM_C || MBEDTLS_CHACHAPOLY_C */
649
650 /**
651 * \brief The generic cipher update function. It encrypts or
652 * decrypts using the given cipher context. Writes as
653 * many block-sized blocks of data as possible to output.
654 * Any data that cannot be written immediately is either
655 * added to the next block, or flushed when
656 * mbedtls_cipher_finish() is called.
657 * Exception: For MBEDTLS_MODE_ECB, expects a single block
658 * in size. For example, 16 Bytes for AES.
659 *
660 * \note If the underlying cipher is used in GCM mode, all calls
661 * to this function, except for the last one before
662 * mbedtls_cipher_finish(), must have \p ilen as a
663 * multiple of the block size of the cipher.
664 *
665 * \param ctx The generic cipher context. This must be initialized and
666 * bound to a key.
667 * \param input The buffer holding the input data. This must be a
668 * readable buffer of at least \p ilen Bytes.
669 * \param ilen The length of the input data.
670 * \param output The buffer for the output data. This must be able to
671 * hold at least `ilen + block_size`. This must not be the
672 * same buffer as \p input.
673 * \param olen The length of the output data, to be updated with the
674 * actual number of Bytes written. This must not be
675 * \c NULL.
676 *
677 * \return \c 0 on success.
678 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
679 * parameter-verification failure.
680 * \return #MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE on an
681 * unsupported mode for a cipher.
682 * \return A cipher-specific error code on failure.
683 */
684 int mbedtls_cipher_update( mbedtls_cipher_context_t *ctx, const unsigned char *input,
685 size_t ilen, unsigned char *output, size_t *olen );
686
687 /**
688 * \brief The generic cipher finalization function. If data still
689 * needs to be flushed from an incomplete block, the data
690 * contained in it is padded to the size of
691 * the last block, and written to the \p output buffer.
692 *
693 * \param ctx The generic cipher context. This must be initialized and
694 * bound to a key.
695 * \param output The buffer to write data to. This needs to be a writable
696 * buffer of at least \p block_size Bytes.
697 * \param olen The length of the data written to the \p output buffer.
698 * This may not be \c NULL.
699 *
700 * \return \c 0 on success.
701 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
702 * parameter-verification failure.
703 * \return #MBEDTLS_ERR_CIPHER_FULL_BLOCK_EXPECTED on decryption
704 * expecting a full block but not receiving one.
705 * \return #MBEDTLS_ERR_CIPHER_INVALID_PADDING on invalid padding
706 * while decrypting.
707 * \return A cipher-specific error code on failure.
708 */
709 int mbedtls_cipher_finish( mbedtls_cipher_context_t *ctx,
710 unsigned char *output, size_t *olen );
711
712 #if defined(MBEDTLS_GCM_C) || defined(MBEDTLS_CHACHAPOLY_C)
713 /**
714 * \brief This function writes a tag for AEAD ciphers.
715 * Currently supported with GCM and ChaCha20+Poly1305.
716 * This must be called after mbedtls_cipher_finish().
717 *
718 * \param ctx The generic cipher context. This must be initialized,
719 * bound to a key, and have just completed a cipher
720 * operation through mbedtls_cipher_finish() the tag for
721 * which should be written.
722 * \param tag The buffer to write the tag to. This must be a writable
723 * buffer of at least \p tag_len Bytes.
724 * \param tag_len The length of the tag to write.
725 *
726 * \return \c 0 on success.
727 * \return A specific error code on failure.
728 */
729 int mbedtls_cipher_write_tag( mbedtls_cipher_context_t *ctx,
730 unsigned char *tag, size_t tag_len );
731
732 /**
733 * \brief This function checks the tag for AEAD ciphers.
734 * Currently supported with GCM and ChaCha20+Poly1305.
735 * This must be called after mbedtls_cipher_finish().
736 *
737 * \param ctx The generic cipher context. This must be initialized.
738 * \param tag The buffer holding the tag. This must be a readable
739 * buffer of at least \p tag_len Bytes.
740 * \param tag_len The length of the tag to check.
741 *
742 * \return \c 0 on success.
743 * \return A specific error code on failure.
744 */
745 int mbedtls_cipher_check_tag( mbedtls_cipher_context_t *ctx,
746 const unsigned char *tag, size_t tag_len );
747 #endif /* MBEDTLS_GCM_C || MBEDTLS_CHACHAPOLY_C */
748
749 /**
750 * \brief The generic all-in-one encryption/decryption function,
751 * for all ciphers except AEAD constructs.
752 *
753 * \param ctx The generic cipher context. This must be initialized.
754 * \param iv The IV to use, or NONCE_COUNTER for CTR-mode ciphers.
755 * This must be a readable buffer of at least \p iv_len
756 * Bytes.
757 * \param iv_len The IV length for ciphers with variable-size IV.
758 * This parameter is discarded by ciphers with fixed-size
759 * IV.
760 * \param input The buffer holding the input data. This must be a
761 * readable buffer of at least \p ilen Bytes.
762 * \param ilen The length of the input data in Bytes.
763 * \param output The buffer for the output data. This must be able to
764 * hold at least `ilen + block_size`. This must not be the
765 * same buffer as \p input.
766 * \param olen The length of the output data, to be updated with the
767 * actual number of Bytes written. This must not be
768 * \c NULL.
769 *
770 * \note Some ciphers do not use IVs nor nonce. For these
771 * ciphers, use \p iv = NULL and \p iv_len = 0.
772 *
773 * \return \c 0 on success.
774 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
775 * parameter-verification failure.
776 * \return #MBEDTLS_ERR_CIPHER_FULL_BLOCK_EXPECTED on decryption
777 * expecting a full block but not receiving one.
778 * \return #MBEDTLS_ERR_CIPHER_INVALID_PADDING on invalid padding
779 * while decrypting.
780 * \return A cipher-specific error code on failure.
781 */
782 int mbedtls_cipher_crypt( mbedtls_cipher_context_t *ctx,
783 const unsigned char *iv, size_t iv_len,
784 const unsigned char *input, size_t ilen,
785 unsigned char *output, size_t *olen );
786
787 #if defined(MBEDTLS_CIPHER_MODE_AEAD)
788 /**
789 * \brief The generic autenticated encryption (AEAD) function.
790 *
791 * \param ctx The generic cipher context. This must be initialized and
792 * bound to a key.
793 * \param iv The IV to use, or NONCE_COUNTER for CTR-mode ciphers.
794 * This must be a readable buffer of at least \p iv_len
795 * Bytes.
796 * \param iv_len The IV length for ciphers with variable-size IV.
797 * This parameter is discarded by ciphers with fixed-size IV.
798 * \param ad The additional data to authenticate. This must be a
799 * readable buffer of at least \p ad_len Bytes.
800 * \param ad_len The length of \p ad.
801 * \param input The buffer holding the input data. This must be a
802 * readable buffer of at least \p ilen Bytes.
803 * \param ilen The length of the input data.
804 * \param output The buffer for the output data. This must be able to
805 * hold at least \p ilen Bytes.
806 * \param olen The length of the output data, to be updated with the
807 * actual number of Bytes written. This must not be
808 * \c NULL.
809 * \param tag The buffer for the authentication tag. This must be a
810 * writable buffer of at least \p tag_len Bytes.
811 * \param tag_len The desired length of the authentication tag.
812 *
813 * \return \c 0 on success.
814 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
815 * parameter-verification failure.
816 * \return A cipher-specific error code on failure.
817 */
818 int mbedtls_cipher_auth_encrypt( mbedtls_cipher_context_t *ctx,
819 const unsigned char *iv, size_t iv_len,
820 const unsigned char *ad, size_t ad_len,
821 const unsigned char *input, size_t ilen,
822 unsigned char *output, size_t *olen,
823 unsigned char *tag, size_t tag_len );
824
825 /**
826 * \brief The generic autenticated decryption (AEAD) function.
827 *
828 * \note If the data is not authentic, then the output buffer
829 * is zeroed out to prevent the unauthentic plaintext being
830 * used, making this interface safer.
831 *
832 * \param ctx The generic cipher context. This must be initialized and
833 * and bound to a key.
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 IV.
839 * \param ad The additional data to be authenticated. This must be a
840 * readable buffer of at least \p ad_len Bytes.
841 * \param ad_len The length of \p ad.
842 * \param input The buffer holding the input data. This must be a
843 * readable buffer of at least \p ilen Bytes.
844 * \param ilen The length of the input data.
845 * \param output The buffer for the output data.
846 * This must be able to hold at least \p ilen Bytes.
847 * \param olen The length of the output data, to be updated with the
848 * actual number of Bytes written. This must not be
849 * \c NULL.
850 * \param tag The buffer holding the authentication tag. This must be
851 * a readable buffer of at least \p tag_len Bytes.
852 * \param tag_len The length of the authentication tag.
853 *
854 * \return \c 0 on success.
855 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
856 * parameter-verification failure.
857 * \return #MBEDTLS_ERR_CIPHER_AUTH_FAILED if data is not authentic.
858 * \return A cipher-specific error code on failure.
859 */
860 int mbedtls_cipher_auth_decrypt( mbedtls_cipher_context_t *ctx,
861 const unsigned char *iv, size_t iv_len,
862 const unsigned char *ad, size_t ad_len,
863 const unsigned char *input, size_t ilen,
864 unsigned char *output, size_t *olen,
865 const unsigned char *tag, size_t tag_len );
866 #endif /* MBEDTLS_CIPHER_MODE_AEAD */
867
868 #ifdef __cplusplus
869 }
870 #endif
871
872 #endif /* MBEDTLS_CIPHER_H */
873