1 /**
2 * \file cipher.h
3 *
4 * \brief This file contains an abstraction interface for use with the cipher
5 * primitives provided by the library. It provides a common interface to all of
6 * the available cipher operations.
7 *
8 * \author Adriaan de Jong <dejong@fox-it.com>
9 */
10 /*
11 * Copyright The Mbed TLS Contributors
12 * SPDX-License-Identifier: Apache-2.0
13 *
14 * Licensed under the Apache License, Version 2.0 (the "License"); you may
15 * not use this file except in compliance with the License.
16 * You may obtain a copy of the License at
17 *
18 * http://www.apache.org/licenses/LICENSE-2.0
19 *
20 * Unless required by applicable law or agreed to in writing, software
21 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
22 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
23 * See the License for the specific language governing permissions and
24 * limitations under the License.
25 */
26
27 #ifndef MBEDTLS_CIPHER_H
28 #define MBEDTLS_CIPHER_H
29 #include "mbedtls/private_access.h"
30
31 #include "mbedtls/build_info.h"
32
33 #include <stddef.h>
34 #include "mbedtls/platform_util.h"
35
36 #if defined(MBEDTLS_GCM_C) || defined(MBEDTLS_CCM_C) || defined(MBEDTLS_CHACHAPOLY_C)
37 #define MBEDTLS_CIPHER_MODE_AEAD
38 #endif
39
40 #if defined(MBEDTLS_CIPHER_MODE_CBC)
41 #define MBEDTLS_CIPHER_MODE_WITH_PADDING
42 #endif
43
44 #if defined(MBEDTLS_CIPHER_NULL_CIPHER) || \
45 defined(MBEDTLS_CHACHA20_C)
46 #define MBEDTLS_CIPHER_MODE_STREAM
47 #endif
48
49 /** The selected feature is not available. */
50 #define MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE -0x6080
51 /** Bad input parameters. */
52 #define MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA -0x6100
53 /** Failed to allocate memory. */
54 #define MBEDTLS_ERR_CIPHER_ALLOC_FAILED -0x6180
55 /** Input data contains invalid padding and is rejected. */
56 #define MBEDTLS_ERR_CIPHER_INVALID_PADDING -0x6200
57 /** Decryption of block requires a full block. */
58 #define MBEDTLS_ERR_CIPHER_FULL_BLOCK_EXPECTED -0x6280
59 /** Authentication failed (for AEAD modes). */
60 #define MBEDTLS_ERR_CIPHER_AUTH_FAILED -0x6300
61 /** The context is invalid. For example, because it was freed. */
62 #define MBEDTLS_ERR_CIPHER_INVALID_CONTEXT -0x6380
63
64 #define MBEDTLS_CIPHER_VARIABLE_IV_LEN 0x01 /**< Cipher accepts IVs of variable length. */
65 #define MBEDTLS_CIPHER_VARIABLE_KEY_LEN 0x02 /**< Cipher accepts keys of variable length. */
66
67 #ifdef __cplusplus
68 extern "C" {
69 #endif
70
71 /**
72 * \brief Supported cipher types.
73 *
74 * \warning DES/3DES are considered weak ciphers and their use
75 * constitutes a security risk. We recommend considering stronger
76 * ciphers instead.
77 */
78 typedef enum {
79 MBEDTLS_CIPHER_ID_NONE = 0, /**< Placeholder to mark the end of cipher ID lists. */
80 MBEDTLS_CIPHER_ID_NULL, /**< The identity cipher, treated as a stream cipher. */
81 MBEDTLS_CIPHER_ID_AES, /**< The AES cipher. */
82 MBEDTLS_CIPHER_ID_DES, /**< The DES cipher. \warning DES is considered weak. */
83 MBEDTLS_CIPHER_ID_3DES, /**< The Triple DES cipher. \warning 3DES is considered weak. */
84 MBEDTLS_CIPHER_ID_CAMELLIA, /**< The Camellia cipher. */
85 MBEDTLS_CIPHER_ID_ARIA, /**< The Aria cipher. */
86 MBEDTLS_CIPHER_ID_CHACHA20, /**< The ChaCha20 cipher. */
87 } mbedtls_cipher_id_t;
88
89 /**
90 * \brief Supported {cipher type, cipher mode} pairs.
91 *
92 * \warning DES/3DES are considered weak ciphers and their use
93 * constitutes a security risk. We recommend considering stronger
94 * ciphers instead.
95 */
96 typedef enum {
97 MBEDTLS_CIPHER_NONE = 0, /**< Placeholder to mark the end of cipher-pair lists. */
98 MBEDTLS_CIPHER_NULL, /**< The identity stream cipher. */
99 MBEDTLS_CIPHER_AES_128_ECB, /**< AES cipher with 128-bit ECB mode. */
100 MBEDTLS_CIPHER_AES_192_ECB, /**< AES cipher with 192-bit ECB mode. */
101 MBEDTLS_CIPHER_AES_256_ECB, /**< AES cipher with 256-bit ECB mode. */
102 MBEDTLS_CIPHER_AES_128_CBC, /**< AES cipher with 128-bit CBC mode. */
103 MBEDTLS_CIPHER_AES_192_CBC, /**< AES cipher with 192-bit CBC mode. */
104 MBEDTLS_CIPHER_AES_256_CBC, /**< AES cipher with 256-bit CBC mode. */
105 MBEDTLS_CIPHER_AES_128_CFB128, /**< AES cipher with 128-bit CFB128 mode. */
106 MBEDTLS_CIPHER_AES_192_CFB128, /**< AES cipher with 192-bit CFB128 mode. */
107 MBEDTLS_CIPHER_AES_256_CFB128, /**< AES cipher with 256-bit CFB128 mode. */
108 MBEDTLS_CIPHER_AES_128_CTR, /**< AES cipher with 128-bit CTR mode. */
109 MBEDTLS_CIPHER_AES_192_CTR, /**< AES cipher with 192-bit CTR mode. */
110 MBEDTLS_CIPHER_AES_256_CTR, /**< AES cipher with 256-bit CTR mode. */
111 MBEDTLS_CIPHER_AES_128_GCM, /**< AES cipher with 128-bit GCM mode. */
112 MBEDTLS_CIPHER_AES_192_GCM, /**< AES cipher with 192-bit GCM mode. */
113 MBEDTLS_CIPHER_AES_256_GCM, /**< AES cipher with 256-bit GCM mode. */
114 MBEDTLS_CIPHER_CAMELLIA_128_ECB, /**< Camellia cipher with 128-bit ECB mode. */
115 MBEDTLS_CIPHER_CAMELLIA_192_ECB, /**< Camellia cipher with 192-bit ECB mode. */
116 MBEDTLS_CIPHER_CAMELLIA_256_ECB, /**< Camellia cipher with 256-bit ECB mode. */
117 MBEDTLS_CIPHER_CAMELLIA_128_CBC, /**< Camellia cipher with 128-bit CBC mode. */
118 MBEDTLS_CIPHER_CAMELLIA_192_CBC, /**< Camellia cipher with 192-bit CBC mode. */
119 MBEDTLS_CIPHER_CAMELLIA_256_CBC, /**< Camellia cipher with 256-bit CBC mode. */
120 MBEDTLS_CIPHER_CAMELLIA_128_CFB128, /**< Camellia cipher with 128-bit CFB128 mode. */
121 MBEDTLS_CIPHER_CAMELLIA_192_CFB128, /**< Camellia cipher with 192-bit CFB128 mode. */
122 MBEDTLS_CIPHER_CAMELLIA_256_CFB128, /**< Camellia cipher with 256-bit CFB128 mode. */
123 MBEDTLS_CIPHER_CAMELLIA_128_CTR, /**< Camellia cipher with 128-bit CTR mode. */
124 MBEDTLS_CIPHER_CAMELLIA_192_CTR, /**< Camellia cipher with 192-bit CTR mode. */
125 MBEDTLS_CIPHER_CAMELLIA_256_CTR, /**< Camellia cipher with 256-bit CTR mode. */
126 MBEDTLS_CIPHER_CAMELLIA_128_GCM, /**< Camellia cipher with 128-bit GCM mode. */
127 MBEDTLS_CIPHER_CAMELLIA_192_GCM, /**< Camellia cipher with 192-bit GCM mode. */
128 MBEDTLS_CIPHER_CAMELLIA_256_GCM, /**< Camellia cipher with 256-bit GCM mode. */
129 MBEDTLS_CIPHER_DES_ECB, /**< DES cipher with ECB mode. \warning DES is considered weak. */
130 MBEDTLS_CIPHER_DES_CBC, /**< DES cipher with CBC mode. \warning DES is considered weak. */
131 MBEDTLS_CIPHER_DES_EDE_ECB, /**< DES cipher with EDE ECB mode. \warning 3DES is considered weak. */
132 MBEDTLS_CIPHER_DES_EDE_CBC, /**< DES cipher with EDE CBC mode. \warning 3DES is considered weak. */
133 MBEDTLS_CIPHER_DES_EDE3_ECB, /**< DES cipher with EDE3 ECB mode. \warning 3DES is considered weak. */
134 MBEDTLS_CIPHER_DES_EDE3_CBC, /**< DES cipher with EDE3 CBC mode. \warning 3DES is considered weak. */
135 MBEDTLS_CIPHER_AES_128_CCM, /**< AES cipher with 128-bit CCM mode. */
136 MBEDTLS_CIPHER_AES_192_CCM, /**< AES cipher with 192-bit CCM mode. */
137 MBEDTLS_CIPHER_AES_256_CCM, /**< AES cipher with 256-bit CCM mode. */
138 MBEDTLS_CIPHER_AES_128_CCM_STAR_NO_TAG, /**< AES cipher with 128-bit CCM_STAR_NO_TAG mode. */
139 MBEDTLS_CIPHER_AES_192_CCM_STAR_NO_TAG, /**< AES cipher with 192-bit CCM_STAR_NO_TAG mode. */
140 MBEDTLS_CIPHER_AES_256_CCM_STAR_NO_TAG, /**< AES cipher with 256-bit CCM_STAR_NO_TAG mode. */
141 MBEDTLS_CIPHER_CAMELLIA_128_CCM, /**< Camellia cipher with 128-bit CCM mode. */
142 MBEDTLS_CIPHER_CAMELLIA_192_CCM, /**< Camellia cipher with 192-bit CCM mode. */
143 MBEDTLS_CIPHER_CAMELLIA_256_CCM, /**< Camellia cipher with 256-bit CCM mode. */
144 MBEDTLS_CIPHER_CAMELLIA_128_CCM_STAR_NO_TAG, /**< Camellia cipher with 128-bit CCM_STAR_NO_TAG mode. */
145 MBEDTLS_CIPHER_CAMELLIA_192_CCM_STAR_NO_TAG, /**< Camellia cipher with 192-bit CCM_STAR_NO_TAG mode. */
146 MBEDTLS_CIPHER_CAMELLIA_256_CCM_STAR_NO_TAG, /**< Camellia cipher with 256-bit CCM_STAR_NO_TAG mode. */
147 MBEDTLS_CIPHER_ARIA_128_ECB, /**< Aria cipher with 128-bit key and ECB mode. */
148 MBEDTLS_CIPHER_ARIA_192_ECB, /**< Aria cipher with 192-bit key and ECB mode. */
149 MBEDTLS_CIPHER_ARIA_256_ECB, /**< Aria cipher with 256-bit key and ECB mode. */
150 MBEDTLS_CIPHER_ARIA_128_CBC, /**< Aria cipher with 128-bit key and CBC mode. */
151 MBEDTLS_CIPHER_ARIA_192_CBC, /**< Aria cipher with 192-bit key and CBC mode. */
152 MBEDTLS_CIPHER_ARIA_256_CBC, /**< Aria cipher with 256-bit key and CBC mode. */
153 MBEDTLS_CIPHER_ARIA_128_CFB128, /**< Aria cipher with 128-bit key and CFB-128 mode. */
154 MBEDTLS_CIPHER_ARIA_192_CFB128, /**< Aria cipher with 192-bit key and CFB-128 mode. */
155 MBEDTLS_CIPHER_ARIA_256_CFB128, /**< Aria cipher with 256-bit key and CFB-128 mode. */
156 MBEDTLS_CIPHER_ARIA_128_CTR, /**< Aria cipher with 128-bit key and CTR mode. */
157 MBEDTLS_CIPHER_ARIA_192_CTR, /**< Aria cipher with 192-bit key and CTR mode. */
158 MBEDTLS_CIPHER_ARIA_256_CTR, /**< Aria cipher with 256-bit key and CTR mode. */
159 MBEDTLS_CIPHER_ARIA_128_GCM, /**< Aria cipher with 128-bit key and GCM mode. */
160 MBEDTLS_CIPHER_ARIA_192_GCM, /**< Aria cipher with 192-bit key and GCM mode. */
161 MBEDTLS_CIPHER_ARIA_256_GCM, /**< Aria cipher with 256-bit key and GCM mode. */
162 MBEDTLS_CIPHER_ARIA_128_CCM, /**< Aria cipher with 128-bit key and CCM mode. */
163 MBEDTLS_CIPHER_ARIA_192_CCM, /**< Aria cipher with 192-bit key and CCM mode. */
164 MBEDTLS_CIPHER_ARIA_256_CCM, /**< Aria cipher with 256-bit key and CCM mode. */
165 MBEDTLS_CIPHER_ARIA_128_CCM_STAR_NO_TAG, /**< Aria cipher with 128-bit key and CCM_STAR_NO_TAG mode. */
166 MBEDTLS_CIPHER_ARIA_192_CCM_STAR_NO_TAG, /**< Aria cipher with 192-bit key and CCM_STAR_NO_TAG mode. */
167 MBEDTLS_CIPHER_ARIA_256_CCM_STAR_NO_TAG, /**< Aria cipher with 256-bit key and CCM_STAR_NO_TAG mode. */
168 MBEDTLS_CIPHER_AES_128_OFB, /**< AES 128-bit cipher in OFB mode. */
169 MBEDTLS_CIPHER_AES_192_OFB, /**< AES 192-bit cipher in OFB mode. */
170 MBEDTLS_CIPHER_AES_256_OFB, /**< AES 256-bit cipher in OFB mode. */
171 MBEDTLS_CIPHER_AES_128_XTS, /**< AES 128-bit cipher in XTS block mode. */
172 MBEDTLS_CIPHER_AES_256_XTS, /**< AES 256-bit cipher in XTS block mode. */
173 MBEDTLS_CIPHER_CHACHA20, /**< ChaCha20 stream cipher. */
174 MBEDTLS_CIPHER_CHACHA20_POLY1305, /**< ChaCha20-Poly1305 AEAD cipher. */
175 MBEDTLS_CIPHER_AES_128_KW, /**< AES cipher with 128-bit NIST KW mode. */
176 MBEDTLS_CIPHER_AES_192_KW, /**< AES cipher with 192-bit NIST KW mode. */
177 MBEDTLS_CIPHER_AES_256_KW, /**< AES cipher with 256-bit NIST KW mode. */
178 MBEDTLS_CIPHER_AES_128_KWP, /**< AES cipher with 128-bit NIST KWP mode. */
179 MBEDTLS_CIPHER_AES_192_KWP, /**< AES cipher with 192-bit NIST KWP mode. */
180 MBEDTLS_CIPHER_AES_256_KWP, /**< AES cipher with 256-bit NIST KWP mode. */
181 } mbedtls_cipher_type_t;
182
183 /** Supported cipher modes. */
184 typedef enum {
185 MBEDTLS_MODE_NONE = 0, /**< None. */
186 MBEDTLS_MODE_ECB, /**< The ECB cipher mode. */
187 MBEDTLS_MODE_CBC, /**< The CBC cipher mode. */
188 MBEDTLS_MODE_CFB, /**< The CFB cipher mode. */
189 MBEDTLS_MODE_OFB, /**< The OFB cipher mode. */
190 MBEDTLS_MODE_CTR, /**< The CTR cipher mode. */
191 MBEDTLS_MODE_GCM, /**< The GCM cipher mode. */
192 MBEDTLS_MODE_STREAM, /**< The stream cipher mode. */
193 MBEDTLS_MODE_CCM, /**< The CCM cipher mode. */
194 MBEDTLS_MODE_CCM_STAR_NO_TAG, /**< The CCM*-no-tag cipher mode. */
195 MBEDTLS_MODE_XTS, /**< The XTS cipher mode. */
196 MBEDTLS_MODE_CHACHAPOLY, /**< The ChaCha-Poly cipher mode. */
197 MBEDTLS_MODE_KW, /**< The SP800-38F KW mode */
198 MBEDTLS_MODE_KWP, /**< The SP800-38F KWP mode */
199 } mbedtls_cipher_mode_t;
200
201 /** Supported cipher padding types. */
202 typedef enum {
203 MBEDTLS_PADDING_PKCS7 = 0, /**< PKCS7 padding (default). */
204 MBEDTLS_PADDING_ONE_AND_ZEROS, /**< ISO/IEC 7816-4 padding. */
205 MBEDTLS_PADDING_ZEROS_AND_LEN, /**< ANSI X.923 padding. */
206 MBEDTLS_PADDING_ZEROS, /**< Zero padding (not reversible). */
207 MBEDTLS_PADDING_NONE, /**< Never pad (full blocks only). */
208 } mbedtls_cipher_padding_t;
209
210 /** Type of operation. */
211 typedef enum {
212 MBEDTLS_OPERATION_NONE = -1,
213 MBEDTLS_DECRYPT = 0,
214 MBEDTLS_ENCRYPT,
215 } mbedtls_operation_t;
216
217 enum {
218 /** Undefined key length. */
219 MBEDTLS_KEY_LENGTH_NONE = 0,
220 /** Key length, in bits (including parity), for DES keys. \warning DES is considered weak. */
221 MBEDTLS_KEY_LENGTH_DES = 64,
222 /** Key length in bits, including parity, for DES in two-key EDE. \warning 3DES is considered weak. */
223 MBEDTLS_KEY_LENGTH_DES_EDE = 128,
224 /** Key length in bits, including parity, for DES in three-key EDE. \warning 3DES is considered weak. */
225 MBEDTLS_KEY_LENGTH_DES_EDE3 = 192,
226 };
227
228 /** Maximum length of any IV, in Bytes. */
229 /* This should ideally be derived automatically from list of ciphers.
230 * This should be kept in sync with MBEDTLS_SSL_MAX_IV_LENGTH defined
231 * in library/ssl_misc.h. */
232 #define MBEDTLS_MAX_IV_LENGTH 16
233
234 /** Maximum block size of any cipher, in Bytes. */
235 /* This should ideally be derived automatically from list of ciphers.
236 * This should be kept in sync with MBEDTLS_SSL_MAX_BLOCK_LENGTH defined
237 * in library/ssl_misc.h. */
238 #define MBEDTLS_MAX_BLOCK_LENGTH 16
239
240 /** Maximum key length, in Bytes. */
241 /* This should ideally be derived automatically from list of ciphers.
242 * For now, only check whether XTS is enabled which uses 64 Byte keys,
243 * and use 32 Bytes as an upper bound for the maximum key length otherwise.
244 * This should be kept in sync with MBEDTLS_SSL_MAX_BLOCK_LENGTH defined
245 * in library/ssl_misc.h, which however deliberately ignores the case of XTS
246 * since the latter isn't used in SSL/TLS. */
247 #if defined(MBEDTLS_CIPHER_MODE_XTS)
248 #define MBEDTLS_MAX_KEY_LENGTH 64
249 #else
250 #define MBEDTLS_MAX_KEY_LENGTH 32
251 #endif /* MBEDTLS_CIPHER_MODE_XTS */
252
253 /**
254 * Base cipher information (opaque struct).
255 */
256 typedef struct mbedtls_cipher_base_t mbedtls_cipher_base_t;
257
258 /**
259 * CMAC context (opaque struct).
260 */
261 typedef struct mbedtls_cmac_context_t mbedtls_cmac_context_t;
262
263 /**
264 * Cipher information. Allows calling cipher functions
265 * in a generic way.
266 *
267 * \note The library does not support custom cipher info structures,
268 * only built-in structures returned by the functions
269 * mbedtls_cipher_info_from_string(),
270 * mbedtls_cipher_info_from_type(),
271 * mbedtls_cipher_info_from_values(),
272 * mbedtls_cipher_info_from_psa().
273 */
274 typedef struct mbedtls_cipher_info_t {
275 /** Full cipher identifier. For example,
276 * MBEDTLS_CIPHER_AES_256_CBC.
277 */
278 mbedtls_cipher_type_t MBEDTLS_PRIVATE(type);
279
280 /** The cipher mode. For example, MBEDTLS_MODE_CBC. */
281 mbedtls_cipher_mode_t MBEDTLS_PRIVATE(mode);
282
283 /** The cipher key length, in bits. This is the
284 * default length for variable sized ciphers.
285 * Includes parity bits for ciphers like DES.
286 */
287 unsigned int MBEDTLS_PRIVATE(key_bitlen);
288
289 /** Name of the cipher. */
290 const char *MBEDTLS_PRIVATE(name);
291
292 /** IV or nonce size, in Bytes.
293 * For ciphers that accept variable IV sizes,
294 * this is the recommended size.
295 */
296 unsigned int MBEDTLS_PRIVATE(iv_size);
297
298 /** Bitflag comprised of MBEDTLS_CIPHER_VARIABLE_IV_LEN and
299 * MBEDTLS_CIPHER_VARIABLE_KEY_LEN indicating whether the
300 * cipher supports variable IV or variable key sizes, respectively.
301 */
302 int MBEDTLS_PRIVATE(flags);
303
304 /** The block size, in Bytes. */
305 unsigned int MBEDTLS_PRIVATE(block_size);
306
307 /** Struct for base cipher information and functions. */
308 const mbedtls_cipher_base_t *MBEDTLS_PRIVATE(base);
309
310 } mbedtls_cipher_info_t;
311
312 /**
313 * Generic cipher context.
314 */
315 typedef struct mbedtls_cipher_context_t {
316 /** Information about the associated cipher. */
317 const mbedtls_cipher_info_t *MBEDTLS_PRIVATE(cipher_info);
318
319 /** Key length to use. */
320 int MBEDTLS_PRIVATE(key_bitlen);
321
322 /** Operation that the key of the context has been
323 * initialized for.
324 */
325 mbedtls_operation_t MBEDTLS_PRIVATE(operation);
326
327 #if defined(MBEDTLS_CIPHER_MODE_WITH_PADDING)
328 /** Padding functions to use, if relevant for
329 * the specific cipher mode.
330 */
331 void(*MBEDTLS_PRIVATE(add_padding))(unsigned char *output, size_t olen, size_t data_len);
332 int(*MBEDTLS_PRIVATE(get_padding))(unsigned char *input, size_t ilen, size_t *data_len);
333 #endif
334
335 /** Buffer for input that has not been processed yet. */
336 unsigned char MBEDTLS_PRIVATE(unprocessed_data)[MBEDTLS_MAX_BLOCK_LENGTH];
337
338 /** Number of Bytes that have not been processed yet. */
339 size_t MBEDTLS_PRIVATE(unprocessed_len);
340
341 /** Current IV or NONCE_COUNTER for CTR-mode, data unit (or sector) number
342 * for XTS-mode. */
343 unsigned char MBEDTLS_PRIVATE(iv)[MBEDTLS_MAX_IV_LENGTH];
344
345 /** IV size in Bytes, for ciphers with variable-length IVs. */
346 size_t MBEDTLS_PRIVATE(iv_size);
347
348 /** The cipher-specific context. */
349 void *MBEDTLS_PRIVATE(cipher_ctx);
350
351 #if defined(MBEDTLS_CMAC_C)
352 /** CMAC-specific context. */
353 mbedtls_cmac_context_t *MBEDTLS_PRIVATE(cmac_ctx);
354 #endif
355
356 #if defined(MBEDTLS_USE_PSA_CRYPTO)
357 /** Indicates whether the cipher operations should be performed
358 * by Mbed TLS' own crypto library or an external implementation
359 * of the PSA Crypto API.
360 * This is unset if the cipher context was established through
361 * mbedtls_cipher_setup(), and set if it was established through
362 * mbedtls_cipher_setup_psa().
363 */
364 unsigned char MBEDTLS_PRIVATE(psa_enabled);
365 #endif /* MBEDTLS_USE_PSA_CRYPTO */
366
367 } mbedtls_cipher_context_t;
368
369 /**
370 * \brief This function retrieves the list of ciphers supported
371 * by the generic cipher module.
372 *
373 * For any cipher identifier in the returned list, you can
374 * obtain the corresponding generic cipher information structure
375 * via mbedtls_cipher_info_from_type(), which can then be used
376 * to prepare a cipher context via mbedtls_cipher_setup().
377 *
378 *
379 * \return A statically-allocated array of cipher identifiers
380 * of type cipher_type_t. The last entry is zero.
381 */
382 const int *mbedtls_cipher_list(void);
383
384 /**
385 * \brief This function retrieves the cipher-information
386 * structure associated with the given cipher name.
387 *
388 * \param cipher_name Name of the cipher to search for. This must not be
389 * \c NULL.
390 *
391 * \return The cipher information structure associated with the
392 * given \p cipher_name.
393 * \return \c NULL if the associated cipher information is not found.
394 */
395 const mbedtls_cipher_info_t *mbedtls_cipher_info_from_string(const char *cipher_name);
396
397 /**
398 * \brief This function retrieves the cipher-information
399 * structure associated with the given cipher type.
400 *
401 * \param cipher_type Type of the cipher to search for.
402 *
403 * \return The cipher information structure associated with the
404 * given \p cipher_type.
405 * \return \c NULL if the associated cipher information is not found.
406 */
407 const mbedtls_cipher_info_t *mbedtls_cipher_info_from_type(const mbedtls_cipher_type_t cipher_type);
408
409 /**
410 * \brief This function retrieves the cipher-information
411 * structure associated with the given cipher ID,
412 * key size and mode.
413 *
414 * \param cipher_id The ID of the cipher to search for. For example,
415 * #MBEDTLS_CIPHER_ID_AES.
416 * \param key_bitlen The length of the key in bits.
417 * \param mode The cipher mode. For example, #MBEDTLS_MODE_CBC.
418 *
419 * \return The cipher information structure associated with the
420 * given \p cipher_id.
421 * \return \c NULL if the associated cipher information is not found.
422 */
423 const mbedtls_cipher_info_t *mbedtls_cipher_info_from_values(const mbedtls_cipher_id_t cipher_id,
424 int key_bitlen,
425 const mbedtls_cipher_mode_t mode);
426
427 /**
428 * \brief Retrieve the identifier for a cipher info structure.
429 *
430 * \param[in] info The cipher info structure to query.
431 * This may be \c NULL.
432 *
433 * \return The full cipher identifier (\c MBEDTLS_CIPHER_xxx).
434 * \return #MBEDTLS_CIPHER_NONE if \p info is \c NULL.
435 */
mbedtls_cipher_info_get_type(const mbedtls_cipher_info_t * info)436 static inline mbedtls_cipher_type_t mbedtls_cipher_info_get_type(
437 const mbedtls_cipher_info_t *info)
438 {
439 if (info == NULL) {
440 return MBEDTLS_CIPHER_NONE;
441 } else {
442 return info->MBEDTLS_PRIVATE(type);
443 }
444 }
445
446 /**
447 * \brief Retrieve the operation mode for a cipher info structure.
448 *
449 * \param[in] info The cipher info structure to query.
450 * This may be \c NULL.
451 *
452 * \return The cipher mode (\c MBEDTLS_MODE_xxx).
453 * \return #MBEDTLS_MODE_NONE if \p info is \c NULL.
454 */
mbedtls_cipher_info_get_mode(const mbedtls_cipher_info_t * info)455 static inline mbedtls_cipher_mode_t mbedtls_cipher_info_get_mode(
456 const mbedtls_cipher_info_t *info)
457 {
458 if (info == NULL) {
459 return MBEDTLS_MODE_NONE;
460 } else {
461 return info->MBEDTLS_PRIVATE(mode);
462 }
463 }
464
465 /**
466 * \brief Retrieve the key size for a cipher info structure.
467 *
468 * \param[in] info The cipher info structure to query.
469 * This may be \c NULL.
470 *
471 * \return The key length in bits.
472 * For variable-sized ciphers, this is the default length.
473 * For DES, this includes the parity bits.
474 * \return \c 0 if \p info is \c NULL.
475 */
mbedtls_cipher_info_get_key_bitlen(const mbedtls_cipher_info_t * info)476 static inline size_t mbedtls_cipher_info_get_key_bitlen(
477 const mbedtls_cipher_info_t *info)
478 {
479 if (info == NULL) {
480 return 0;
481 } else {
482 return info->MBEDTLS_PRIVATE(key_bitlen);
483 }
484 }
485
486 /**
487 * \brief Retrieve the human-readable name for a
488 * cipher info structure.
489 *
490 * \param[in] info The cipher info structure to query.
491 * This may be \c NULL.
492 *
493 * \return The cipher name, which is a human readable string,
494 * with static storage duration.
495 * \return \c NULL if \c info is \p NULL.
496 */
mbedtls_cipher_info_get_name(const mbedtls_cipher_info_t * info)497 static inline const char *mbedtls_cipher_info_get_name(
498 const mbedtls_cipher_info_t *info)
499 {
500 if (info == NULL) {
501 return NULL;
502 } else {
503 return info->MBEDTLS_PRIVATE(name);
504 }
505 }
506
507 /**
508 * \brief This function returns the size of the IV or nonce
509 * for the cipher info structure, in bytes.
510 *
511 * \param info The cipher info structure. This may be \c NULL.
512 *
513 * \return The recommended IV size.
514 * \return \c 0 for ciphers not using an IV or a nonce.
515 * \return \c 0 if \p info is \c NULL.
516 */
mbedtls_cipher_info_get_iv_size(const mbedtls_cipher_info_t * info)517 static inline size_t mbedtls_cipher_info_get_iv_size(
518 const mbedtls_cipher_info_t *info)
519 {
520 if (info == NULL) {
521 return 0;
522 }
523
524 return (size_t) info->MBEDTLS_PRIVATE(iv_size);
525 }
526
527 /**
528 * \brief This function returns the block size of the given
529 * cipher info structure in bytes.
530 *
531 * \param info The cipher info structure. This may be \c NULL.
532 *
533 * \return The block size of the cipher.
534 * \return \c 1 if the cipher is a stream cipher.
535 * \return \c 0 if \p info is \c NULL.
536 */
mbedtls_cipher_info_get_block_size(const mbedtls_cipher_info_t * info)537 static inline size_t mbedtls_cipher_info_get_block_size(
538 const mbedtls_cipher_info_t *info)
539 {
540 if (info == NULL) {
541 return 0;
542 }
543
544 return (size_t) info->MBEDTLS_PRIVATE(block_size);
545 }
546
547 /**
548 * \brief This function returns a non-zero value if the key length for
549 * the given cipher is variable.
550 *
551 * \param info The cipher info structure. This may be \c NULL.
552 *
553 * \return Non-zero if the key length is variable, \c 0 otherwise.
554 * \return \c 0 if the given pointer is \c NULL.
555 */
mbedtls_cipher_info_has_variable_key_bitlen(const mbedtls_cipher_info_t * info)556 static inline int mbedtls_cipher_info_has_variable_key_bitlen(
557 const mbedtls_cipher_info_t *info)
558 {
559 if (info == NULL) {
560 return 0;
561 }
562
563 return info->MBEDTLS_PRIVATE(flags) & MBEDTLS_CIPHER_VARIABLE_KEY_LEN;
564 }
565
566 /**
567 * \brief This function returns a non-zero value if the IV size for
568 * the given cipher is variable.
569 *
570 * \param info The cipher info structure. This may be \c NULL.
571 *
572 * \return Non-zero if the IV size is variable, \c 0 otherwise.
573 * \return \c 0 if the given pointer is \c NULL.
574 */
mbedtls_cipher_info_has_variable_iv_size(const mbedtls_cipher_info_t * info)575 static inline int mbedtls_cipher_info_has_variable_iv_size(
576 const mbedtls_cipher_info_t *info)
577 {
578 if (info == NULL) {
579 return 0;
580 }
581
582 return info->MBEDTLS_PRIVATE(flags) & MBEDTLS_CIPHER_VARIABLE_IV_LEN;
583 }
584
585 /**
586 * \brief This function initializes a \p cipher_context as NONE.
587 *
588 * \param ctx The context to be initialized. This must not be \c NULL.
589 */
590 void mbedtls_cipher_init(mbedtls_cipher_context_t *ctx);
591
592 /**
593 * \brief This function frees and clears the cipher-specific
594 * context of \p ctx. Freeing \p ctx itself remains the
595 * responsibility of the caller.
596 *
597 * \param ctx The context to be freed. If this is \c NULL, the
598 * function has no effect, otherwise this must point to an
599 * initialized context.
600 */
601 void mbedtls_cipher_free(mbedtls_cipher_context_t *ctx);
602
603
604 /**
605 * \brief This function prepares a cipher context for
606 * use with the given cipher primitive.
607 *
608 * \note After calling this function, you should call
609 * mbedtls_cipher_setkey() and, if the mode uses padding,
610 * mbedtls_cipher_set_padding_mode(), then for each
611 * message to encrypt or decrypt with this key, either:
612 * - mbedtls_cipher_crypt() for one-shot processing with
613 * non-AEAD modes;
614 * - mbedtls_cipher_auth_encrypt_ext() or
615 * mbedtls_cipher_auth_decrypt_ext() for one-shot
616 * processing with AEAD modes or NIST_KW;
617 * - for multi-part processing, see the documentation of
618 * mbedtls_cipher_reset().
619 *
620 * \param ctx The context to prepare. This must be initialized by
621 * a call to mbedtls_cipher_init() first.
622 * \param cipher_info The cipher to use.
623 *
624 * \return \c 0 on success.
625 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
626 * parameter-verification failure.
627 * \return #MBEDTLS_ERR_CIPHER_ALLOC_FAILED if allocation of the
628 * cipher-specific context fails.
629 */
630 int mbedtls_cipher_setup(mbedtls_cipher_context_t *ctx,
631 const mbedtls_cipher_info_t *cipher_info);
632
633 #if defined(MBEDTLS_USE_PSA_CRYPTO)
634 #if !defined(MBEDTLS_DEPRECATED_REMOVED)
635 /**
636 * \brief This function initializes a cipher context for
637 * PSA-based use with the given cipher primitive.
638 *
639 * \deprecated This function is deprecated and will be removed in a
640 * future version of the library.
641 * Please use psa_aead_xxx() / psa_cipher_xxx() directly
642 * instead.
643 *
644 * \note See #MBEDTLS_USE_PSA_CRYPTO for information on PSA.
645 *
646 * \param ctx The context to initialize. May not be \c NULL.
647 * \param cipher_info The cipher to use.
648 * \param taglen For AEAD ciphers, the length in bytes of the
649 * authentication tag to use. Subsequent uses of
650 * mbedtls_cipher_auth_encrypt_ext() or
651 * mbedtls_cipher_auth_decrypt_ext() must provide
652 * the same tag length.
653 * For non-AEAD ciphers, the value must be \c 0.
654 *
655 * \return \c 0 on success.
656 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
657 * parameter-verification failure.
658 * \return #MBEDTLS_ERR_CIPHER_ALLOC_FAILED if allocation of the
659 * cipher-specific context fails.
660 */
661 int MBEDTLS_DEPRECATED mbedtls_cipher_setup_psa(mbedtls_cipher_context_t *ctx,
662 const mbedtls_cipher_info_t *cipher_info,
663 size_t taglen);
664 #endif /* MBEDTLS_DEPRECATED_REMOVED */
665 #endif /* MBEDTLS_USE_PSA_CRYPTO */
666
667 /**
668 * \brief This function returns the block size of the given cipher
669 * in bytes.
670 *
671 * \param ctx The context of the cipher.
672 *
673 * \return The block size of the underlying cipher.
674 * \return \c 1 if the cipher is a stream cipher.
675 * \return \c 0 if \p ctx has not been initialized.
676 */
mbedtls_cipher_get_block_size(const mbedtls_cipher_context_t * ctx)677 static inline unsigned int mbedtls_cipher_get_block_size(
678 const mbedtls_cipher_context_t *ctx)
679 {
680 MBEDTLS_INTERNAL_VALIDATE_RET(ctx != NULL, 0);
681 if (ctx->MBEDTLS_PRIVATE(cipher_info) == NULL) {
682 return 0;
683 }
684
685 return ctx->MBEDTLS_PRIVATE(cipher_info)->MBEDTLS_PRIVATE(block_size);
686 }
687
688 /**
689 * \brief This function returns the mode of operation for
690 * the cipher. For example, MBEDTLS_MODE_CBC.
691 *
692 * \param ctx The context of the cipher. This must be initialized.
693 *
694 * \return The mode of operation.
695 * \return #MBEDTLS_MODE_NONE if \p ctx has not been initialized.
696 */
mbedtls_cipher_get_cipher_mode(const mbedtls_cipher_context_t * ctx)697 static inline mbedtls_cipher_mode_t mbedtls_cipher_get_cipher_mode(
698 const mbedtls_cipher_context_t *ctx)
699 {
700 MBEDTLS_INTERNAL_VALIDATE_RET(ctx != NULL, MBEDTLS_MODE_NONE);
701 if (ctx->MBEDTLS_PRIVATE(cipher_info) == NULL) {
702 return MBEDTLS_MODE_NONE;
703 }
704
705 return ctx->MBEDTLS_PRIVATE(cipher_info)->MBEDTLS_PRIVATE(mode);
706 }
707
708 /**
709 * \brief This function returns the size of the IV or nonce
710 * of the cipher, in Bytes.
711 *
712 * \param ctx The context of the cipher. This must be initialized.
713 *
714 * \return The recommended IV size if no IV has been set.
715 * \return \c 0 for ciphers not using an IV or a nonce.
716 * \return The actual size if an IV has been set.
717 */
mbedtls_cipher_get_iv_size(const mbedtls_cipher_context_t * ctx)718 static inline int mbedtls_cipher_get_iv_size(
719 const mbedtls_cipher_context_t *ctx)
720 {
721 MBEDTLS_INTERNAL_VALIDATE_RET(ctx != NULL, 0);
722 if (ctx->MBEDTLS_PRIVATE(cipher_info) == NULL) {
723 return 0;
724 }
725
726 if (ctx->MBEDTLS_PRIVATE(iv_size) != 0) {
727 return (int) ctx->MBEDTLS_PRIVATE(iv_size);
728 }
729
730 return (int) ctx->MBEDTLS_PRIVATE(cipher_info)->MBEDTLS_PRIVATE(iv_size);
731 }
732
733 /**
734 * \brief This function returns the type of the given cipher.
735 *
736 * \param ctx The context of the cipher. This must be initialized.
737 *
738 * \return The type of the cipher.
739 * \return #MBEDTLS_CIPHER_NONE if \p ctx has not been initialized.
740 */
mbedtls_cipher_get_type(const mbedtls_cipher_context_t * ctx)741 static inline mbedtls_cipher_type_t mbedtls_cipher_get_type(
742 const mbedtls_cipher_context_t *ctx)
743 {
744 MBEDTLS_INTERNAL_VALIDATE_RET(
745 ctx != NULL, MBEDTLS_CIPHER_NONE);
746 if (ctx->MBEDTLS_PRIVATE(cipher_info) == NULL) {
747 return MBEDTLS_CIPHER_NONE;
748 }
749
750 return ctx->MBEDTLS_PRIVATE(cipher_info)->MBEDTLS_PRIVATE(type);
751 }
752
753 /**
754 * \brief This function returns the name of the given cipher
755 * as a string.
756 *
757 * \param ctx The context of the cipher. This must be initialized.
758 *
759 * \return The name of the cipher.
760 * \return NULL if \p ctx has not been not initialized.
761 */
mbedtls_cipher_get_name(const mbedtls_cipher_context_t * ctx)762 static inline const char *mbedtls_cipher_get_name(
763 const mbedtls_cipher_context_t *ctx)
764 {
765 MBEDTLS_INTERNAL_VALIDATE_RET(ctx != NULL, 0);
766 if (ctx->MBEDTLS_PRIVATE(cipher_info) == NULL) {
767 return 0;
768 }
769
770 return ctx->MBEDTLS_PRIVATE(cipher_info)->MBEDTLS_PRIVATE(name);
771 }
772
773 /**
774 * \brief This function returns the key length of the cipher.
775 *
776 * \param ctx The context of the cipher. This must be initialized.
777 *
778 * \return The key length of the cipher in bits.
779 * \return #MBEDTLS_KEY_LENGTH_NONE if ctx \p has not been
780 * initialized.
781 */
mbedtls_cipher_get_key_bitlen(const mbedtls_cipher_context_t * ctx)782 static inline int mbedtls_cipher_get_key_bitlen(
783 const mbedtls_cipher_context_t *ctx)
784 {
785 MBEDTLS_INTERNAL_VALIDATE_RET(
786 ctx != NULL, MBEDTLS_KEY_LENGTH_NONE);
787 if (ctx->MBEDTLS_PRIVATE(cipher_info) == NULL) {
788 return MBEDTLS_KEY_LENGTH_NONE;
789 }
790
791 return (int) ctx->MBEDTLS_PRIVATE(cipher_info)->MBEDTLS_PRIVATE(key_bitlen);
792 }
793
794 /**
795 * \brief This function returns the operation of the given cipher.
796 *
797 * \param ctx The context of the cipher. This must be initialized.
798 *
799 * \return The type of operation: #MBEDTLS_ENCRYPT or #MBEDTLS_DECRYPT.
800 * \return #MBEDTLS_OPERATION_NONE if \p ctx has not been initialized.
801 */
mbedtls_cipher_get_operation(const mbedtls_cipher_context_t * ctx)802 static inline mbedtls_operation_t mbedtls_cipher_get_operation(
803 const mbedtls_cipher_context_t *ctx)
804 {
805 MBEDTLS_INTERNAL_VALIDATE_RET(
806 ctx != NULL, MBEDTLS_OPERATION_NONE);
807 if (ctx->MBEDTLS_PRIVATE(cipher_info) == NULL) {
808 return MBEDTLS_OPERATION_NONE;
809 }
810
811 return ctx->MBEDTLS_PRIVATE(operation);
812 }
813
814 /**
815 * \brief This function sets the key to use with the given context.
816 *
817 * \param ctx The generic cipher context. This must be initialized and
818 * bound to a cipher information structure.
819 * \param key The key to use. This must be a readable buffer of at
820 * least \p key_bitlen Bits.
821 * \param key_bitlen The key length to use, in Bits.
822 * \param operation The operation that the key will be used for:
823 * #MBEDTLS_ENCRYPT or #MBEDTLS_DECRYPT.
824 *
825 * \return \c 0 on success.
826 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
827 * parameter-verification failure.
828 * \return A cipher-specific error code on failure.
829 */
830 int mbedtls_cipher_setkey(mbedtls_cipher_context_t *ctx,
831 const unsigned char *key,
832 int key_bitlen,
833 const mbedtls_operation_t operation);
834
835 #if defined(MBEDTLS_CIPHER_MODE_WITH_PADDING)
836 /**
837 * \brief This function sets the padding mode, for cipher modes
838 * that use padding.
839 *
840 * The default passing mode is PKCS7 padding.
841 *
842 * \param ctx The generic cipher context. This must be initialized and
843 * bound to a cipher information structure.
844 * \param mode The padding mode.
845 *
846 * \return \c 0 on success.
847 * \return #MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE
848 * if the selected padding mode is not supported.
849 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA if the cipher mode
850 * does not support padding.
851 */
852 int mbedtls_cipher_set_padding_mode(mbedtls_cipher_context_t *ctx,
853 mbedtls_cipher_padding_t mode);
854 #endif /* MBEDTLS_CIPHER_MODE_WITH_PADDING */
855
856 /**
857 * \brief This function sets the initialization vector (IV)
858 * or nonce.
859 *
860 * \note Some ciphers do not use IVs nor nonce. For these
861 * ciphers, this function has no effect.
862 *
863 * \note For #MBEDTLS_CIPHER_CHACHA20, the nonce length must
864 * be 12, and the initial counter value is 0.
865 *
866 * \note For #MBEDTLS_CIPHER_CHACHA20_POLY1305, the nonce length
867 * must be 12.
868 *
869 * \param ctx The generic cipher context. This must be initialized and
870 * bound to a cipher information structure.
871 * \param iv The IV to use, or NONCE_COUNTER for CTR-mode ciphers. This
872 * must be a readable buffer of at least \p iv_len Bytes.
873 * \param iv_len The IV length for ciphers with variable-size IV.
874 * This parameter is discarded by ciphers with fixed-size IV.
875 *
876 * \return \c 0 on success.
877 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
878 * parameter-verification failure.
879 */
880 int mbedtls_cipher_set_iv(mbedtls_cipher_context_t *ctx,
881 const unsigned char *iv,
882 size_t iv_len);
883
884 /**
885 * \brief This function resets the cipher state.
886 *
887 * \note With non-AEAD ciphers, the order of calls for each message
888 * is as follows:
889 * 1. mbedtls_cipher_set_iv() if the mode uses an IV/nonce.
890 * 2. mbedtls_cipher_reset()
891 * 3. mbedtls_cipher_update() one or more times
892 * 4. mbedtls_cipher_finish()
893 * .
894 * This sequence can be repeated to encrypt or decrypt multiple
895 * messages with the same key.
896 *
897 * \note With AEAD ciphers, the order of calls for each message
898 * is as follows:
899 * 1. mbedtls_cipher_set_iv() if the mode uses an IV/nonce.
900 * 2. mbedtls_cipher_reset()
901 * 3. mbedtls_cipher_update_ad()
902 * 4. mbedtls_cipher_update() one or more times
903 * 5. mbedtls_cipher_finish()
904 * 6. mbedtls_cipher_check_tag() (for decryption) or
905 * mbedtls_cipher_write_tag() (for encryption).
906 * .
907 * This sequence can be repeated to encrypt or decrypt multiple
908 * messages with the same key.
909 *
910 * \param ctx The generic cipher context. This must be bound to a key.
911 *
912 * \return \c 0 on success.
913 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
914 * parameter-verification failure.
915 */
916 int mbedtls_cipher_reset(mbedtls_cipher_context_t *ctx);
917
918 #if defined(MBEDTLS_GCM_C) || defined(MBEDTLS_CHACHAPOLY_C)
919 /**
920 * \brief This function adds additional data for AEAD ciphers.
921 * Currently supported with GCM and ChaCha20+Poly1305.
922 *
923 * \param ctx The generic cipher context. This must be initialized.
924 * \param ad The additional data to use. This must be a readable
925 * buffer of at least \p ad_len Bytes.
926 * \param ad_len The length of \p ad in Bytes.
927 *
928 * \return \c 0 on success.
929 * \return A specific error code on failure.
930 */
931 int mbedtls_cipher_update_ad(mbedtls_cipher_context_t *ctx,
932 const unsigned char *ad, size_t ad_len);
933 #endif /* MBEDTLS_GCM_C || MBEDTLS_CHACHAPOLY_C */
934
935 /**
936 * \brief The generic cipher update function. It encrypts or
937 * decrypts using the given cipher context. Writes as
938 * many block-sized blocks of data as possible to output.
939 * Any data that cannot be written immediately is either
940 * added to the next block, or flushed when
941 * mbedtls_cipher_finish() is called.
942 * Exception: For MBEDTLS_MODE_ECB, expects a single block
943 * in size. For example, 16 Bytes for AES.
944 *
945 * \param ctx The generic cipher context. This must be initialized and
946 * bound to a key.
947 * \param input The buffer holding the input data. This must be a
948 * readable buffer of at least \p ilen Bytes.
949 * \param ilen The length of the input data.
950 * \param output The buffer for the output data. This must be able to
951 * hold at least `ilen + block_size`. This must not be the
952 * same buffer as \p input.
953 * \param olen The length of the output data, to be updated with the
954 * actual number of Bytes written. This must not be
955 * \c NULL.
956 *
957 * \return \c 0 on success.
958 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
959 * parameter-verification failure.
960 * \return #MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE on an
961 * unsupported mode for a cipher.
962 * \return A cipher-specific error code on failure.
963 */
964 int mbedtls_cipher_update(mbedtls_cipher_context_t *ctx,
965 const unsigned char *input,
966 size_t ilen, unsigned char *output,
967 size_t *olen);
968
969 /**
970 * \brief The generic cipher finalization function. If data still
971 * needs to be flushed from an incomplete block, the data
972 * contained in it is padded to the size of
973 * the last block, and written to the \p output buffer.
974 *
975 * \param ctx The generic cipher context. This must be initialized and
976 * bound to a key.
977 * \param output The buffer to write data to. This needs to be a writable
978 * buffer of at least \p block_size Bytes.
979 * \param olen The length of the data written to the \p output buffer.
980 * This may not be \c NULL.
981 *
982 * \return \c 0 on success.
983 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
984 * parameter-verification failure.
985 * \return #MBEDTLS_ERR_CIPHER_FULL_BLOCK_EXPECTED on decryption
986 * expecting a full block but not receiving one.
987 * \return #MBEDTLS_ERR_CIPHER_INVALID_PADDING on invalid padding
988 * while decrypting.
989 * \return A cipher-specific error code on failure.
990 */
991 int mbedtls_cipher_finish(mbedtls_cipher_context_t *ctx,
992 unsigned char *output, size_t *olen);
993
994 #if defined(MBEDTLS_GCM_C) || defined(MBEDTLS_CHACHAPOLY_C)
995 /**
996 * \brief This function writes a tag for AEAD ciphers.
997 * Currently supported with GCM and ChaCha20+Poly1305.
998 * This must be called after mbedtls_cipher_finish().
999 *
1000 * \param ctx The generic cipher context. This must be initialized,
1001 * bound to a key, and have just completed a cipher
1002 * operation through mbedtls_cipher_finish() the tag for
1003 * which should be written.
1004 * \param tag The buffer to write the tag to. This must be a writable
1005 * buffer of at least \p tag_len Bytes.
1006 * \param tag_len The length of the tag to write.
1007 *
1008 * \return \c 0 on success.
1009 * \return A specific error code on failure.
1010 */
1011 int mbedtls_cipher_write_tag(mbedtls_cipher_context_t *ctx,
1012 unsigned char *tag, size_t tag_len);
1013
1014 /**
1015 * \brief This function checks the tag for AEAD ciphers.
1016 * Currently supported with GCM and ChaCha20+Poly1305.
1017 * This must be called after mbedtls_cipher_finish().
1018 *
1019 * \param ctx The generic cipher context. This must be initialized.
1020 * \param tag The buffer holding the tag. This must be a readable
1021 * buffer of at least \p tag_len Bytes.
1022 * \param tag_len The length of the tag to check.
1023 *
1024 * \return \c 0 on success.
1025 * \return A specific error code on failure.
1026 */
1027 int mbedtls_cipher_check_tag(mbedtls_cipher_context_t *ctx,
1028 const unsigned char *tag, size_t tag_len);
1029 #endif /* MBEDTLS_GCM_C || MBEDTLS_CHACHAPOLY_C */
1030
1031 /**
1032 * \brief The generic all-in-one encryption/decryption function,
1033 * for all ciphers except AEAD constructs.
1034 *
1035 * \param ctx The generic cipher context. This must be initialized.
1036 * \param iv The IV to use, or NONCE_COUNTER for CTR-mode ciphers.
1037 * This must be a readable buffer of at least \p iv_len
1038 * Bytes.
1039 * \param iv_len The IV length for ciphers with variable-size IV.
1040 * This parameter is discarded by ciphers with fixed-size
1041 * IV.
1042 * \param input The buffer holding the input data. This must be a
1043 * readable buffer of at least \p ilen Bytes.
1044 * \param ilen The length of the input data in Bytes.
1045 * \param output The buffer for the output data. This must be able to
1046 * hold at least `ilen + block_size`. This must not be the
1047 * same buffer as \p input.
1048 * \param olen The length of the output data, to be updated with the
1049 * actual number of Bytes written. This must not be
1050 * \c NULL.
1051 *
1052 * \note Some ciphers do not use IVs nor nonce. For these
1053 * ciphers, use \p iv = NULL and \p iv_len = 0.
1054 *
1055 * \return \c 0 on success.
1056 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
1057 * parameter-verification failure.
1058 * \return #MBEDTLS_ERR_CIPHER_FULL_BLOCK_EXPECTED on decryption
1059 * expecting a full block but not receiving one.
1060 * \return #MBEDTLS_ERR_CIPHER_INVALID_PADDING on invalid padding
1061 * while decrypting.
1062 * \return A cipher-specific error code on failure.
1063 */
1064 int mbedtls_cipher_crypt(mbedtls_cipher_context_t *ctx,
1065 const unsigned char *iv, size_t iv_len,
1066 const unsigned char *input, size_t ilen,
1067 unsigned char *output, size_t *olen);
1068
1069 #if defined(MBEDTLS_CIPHER_MODE_AEAD) || defined(MBEDTLS_NIST_KW_C)
1070 /**
1071 * \brief The authenticated encryption (AEAD/NIST_KW) function.
1072 *
1073 * \note For AEAD modes, the tag will be appended to the
1074 * ciphertext, as recommended by RFC 5116.
1075 * (NIST_KW doesn't have a separate tag.)
1076 *
1077 * \param ctx The generic cipher context. This must be initialized and
1078 * bound to a key, with an AEAD algorithm or NIST_KW.
1079 * \param iv The nonce to use. This must be a readable buffer of
1080 * at least \p iv_len Bytes and may be \c NULL if \p
1081 * iv_len is \c 0.
1082 * \param iv_len The length of the nonce. For AEAD ciphers, this must
1083 * satisfy the constraints imposed by the cipher used.
1084 * For NIST_KW, this must be \c 0.
1085 * \param ad The additional data to authenticate. This must be a
1086 * readable buffer of at least \p ad_len Bytes, and may
1087 * be \c NULL is \p ad_len is \c 0.
1088 * \param ad_len The length of \p ad. For NIST_KW, this must be \c 0.
1089 * \param input The buffer holding the input data. This must be a
1090 * readable buffer of at least \p ilen Bytes, and may be
1091 * \c NULL if \p ilen is \c 0.
1092 * \param ilen The length of the input data.
1093 * \param output The buffer for the output data. This must be a
1094 * writable buffer of at least \p output_len Bytes, and
1095 * must not be \c NULL.
1096 * \param output_len The length of the \p output buffer in Bytes. For AEAD
1097 * ciphers, this must be at least \p ilen + \p tag_len.
1098 * For NIST_KW, this must be at least \p ilen + 8
1099 * (rounded up to a multiple of 8 if KWP is used);
1100 * \p ilen + 15 is always a safe value.
1101 * \param olen This will be filled with the actual number of Bytes
1102 * written to the \p output buffer. This must point to a
1103 * writable object of type \c size_t.
1104 * \param tag_len The desired length of the authentication tag. For AEAD
1105 * ciphers, this must match the constraints imposed by
1106 * the cipher used, and in particular must not be \c 0.
1107 * For NIST_KW, this must be \c 0.
1108 *
1109 * \return \c 0 on success.
1110 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
1111 * parameter-verification failure.
1112 * \return A cipher-specific error code on failure.
1113 */
1114 int mbedtls_cipher_auth_encrypt_ext(mbedtls_cipher_context_t *ctx,
1115 const unsigned char *iv, size_t iv_len,
1116 const unsigned char *ad, size_t ad_len,
1117 const unsigned char *input, size_t ilen,
1118 unsigned char *output, size_t output_len,
1119 size_t *olen, size_t tag_len);
1120
1121 /**
1122 * \brief The authenticated encryption (AEAD/NIST_KW) function.
1123 *
1124 * \note If the data is not authentic, then the output buffer
1125 * is zeroed out to prevent the unauthentic plaintext being
1126 * used, making this interface safer.
1127 *
1128 * \note For AEAD modes, the tag must be appended to the
1129 * ciphertext, as recommended by RFC 5116.
1130 * (NIST_KW doesn't have a separate tag.)
1131 *
1132 * \param ctx The generic cipher context. This must be initialized and
1133 * bound to a key, with an AEAD algorithm or NIST_KW.
1134 * \param iv The nonce to use. This must be a readable buffer of
1135 * at least \p iv_len Bytes and may be \c NULL if \p
1136 * iv_len is \c 0.
1137 * \param iv_len The length of the nonce. For AEAD ciphers, this must
1138 * satisfy the constraints imposed by the cipher used.
1139 * For NIST_KW, this must be \c 0.
1140 * \param ad The additional data to authenticate. This must be a
1141 * readable buffer of at least \p ad_len Bytes, and may
1142 * be \c NULL is \p ad_len is \c 0.
1143 * \param ad_len The length of \p ad. For NIST_KW, this must be \c 0.
1144 * \param input The buffer holding the input data. This must be a
1145 * readable buffer of at least \p ilen Bytes, and may be
1146 * \c NULL if \p ilen is \c 0.
1147 * \param ilen The length of the input data. For AEAD ciphers this
1148 * must be at least \p tag_len. For NIST_KW this must be
1149 * at least \c 8.
1150 * \param output The buffer for the output data. This must be a
1151 * writable buffer of at least \p output_len Bytes, and
1152 * may be \c NULL if \p output_len is \c 0.
1153 * \param output_len The length of the \p output buffer in Bytes. For AEAD
1154 * ciphers, this must be at least \p ilen - \p tag_len.
1155 * For NIST_KW, this must be at least \p ilen - 8.
1156 * \param olen This will be filled with the actual number of Bytes
1157 * written to the \p output buffer. This must point to a
1158 * writable object of type \c size_t.
1159 * \param tag_len The actual length of the authentication tag. For AEAD
1160 * ciphers, this must match the constraints imposed by
1161 * the cipher used, and in particular must not be \c 0.
1162 * For NIST_KW, this must be \c 0.
1163 *
1164 * \return \c 0 on success.
1165 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
1166 * parameter-verification failure.
1167 * \return #MBEDTLS_ERR_CIPHER_AUTH_FAILED if data is not authentic.
1168 * \return A cipher-specific error code on failure.
1169 */
1170 int mbedtls_cipher_auth_decrypt_ext(mbedtls_cipher_context_t *ctx,
1171 const unsigned char *iv, size_t iv_len,
1172 const unsigned char *ad, size_t ad_len,
1173 const unsigned char *input, size_t ilen,
1174 unsigned char *output, size_t output_len,
1175 size_t *olen, size_t tag_len);
1176 #endif /* MBEDTLS_CIPHER_MODE_AEAD || MBEDTLS_NIST_KW_C */
1177 #ifdef __cplusplus
1178 }
1179 #endif
1180
1181 #endif /* MBEDTLS_CIPHER_H */
1182