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