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,
333 size_t data_len);
334 /* Report invalid-padding condition through the output parameter
335 * invalid_padding. To minimize changes in Mbed TLS 3.6, where this
336 * declaration is in a public header, use the public type size_t
337 * rather than the internal type mbedtls_ct_condition_t. */
338 int(*MBEDTLS_PRIVATE(get_padding))(unsigned char *input, size_t ilen,
339 size_t *data_len,
340 size_t *invalid_padding);
341 #endif
342
343 /** Buffer for input that has not been processed yet. */
344 unsigned char MBEDTLS_PRIVATE(unprocessed_data)[MBEDTLS_MAX_BLOCK_LENGTH];
345
346 /** Number of Bytes that have not been processed yet. */
347 size_t MBEDTLS_PRIVATE(unprocessed_len);
348
349 /** Current IV or NONCE_COUNTER for CTR-mode, data unit (or sector) number
350 * for XTS-mode. */
351 unsigned char MBEDTLS_PRIVATE(iv)[MBEDTLS_MAX_IV_LENGTH];
352
353 /** IV size in Bytes, for ciphers with variable-length IVs. */
354 size_t MBEDTLS_PRIVATE(iv_size);
355
356 /** The cipher-specific context. */
357 void *MBEDTLS_PRIVATE(cipher_ctx);
358
359 #if defined(MBEDTLS_CMAC_C)
360 /** CMAC-specific context. */
361 mbedtls_cmac_context_t *MBEDTLS_PRIVATE(cmac_ctx);
362 #endif
363
364 #if defined(MBEDTLS_USE_PSA_CRYPTO) && !defined(MBEDTLS_DEPRECATED_REMOVED)
365 /** Indicates whether the cipher operations should be performed
366 * by Mbed TLS' own crypto library or an external implementation
367 * of the PSA Crypto API.
368 * This is unset if the cipher context was established through
369 * mbedtls_cipher_setup(), and set if it was established through
370 * mbedtls_cipher_setup_psa().
371 */
372 unsigned char MBEDTLS_PRIVATE(psa_enabled);
373 #endif /* MBEDTLS_USE_PSA_CRYPTO && !MBEDTLS_DEPRECATED_REMOVED */
374
375 } mbedtls_cipher_context_t;
376
377 /**
378 * \brief This function retrieves the list of ciphers supported
379 * by the generic cipher module.
380 *
381 * For any cipher identifier in the returned list, you can
382 * obtain the corresponding generic cipher information structure
383 * via mbedtls_cipher_info_from_type(), which can then be used
384 * to prepare a cipher context via mbedtls_cipher_setup().
385 *
386 *
387 * \return A statically-allocated array of cipher identifiers
388 * of type cipher_type_t. The last entry is zero.
389 */
390 const int *mbedtls_cipher_list(void);
391
392 /**
393 * \brief This function retrieves the cipher-information
394 * structure associated with the given cipher name.
395 *
396 * \param cipher_name Name of the cipher to search for. This must not be
397 * \c NULL.
398 *
399 * \return The cipher information structure associated with the
400 * given \p cipher_name.
401 * \return \c NULL if the associated cipher information is not found.
402 */
403 const mbedtls_cipher_info_t *mbedtls_cipher_info_from_string(const char *cipher_name);
404
405 /**
406 * \brief This function retrieves the cipher-information
407 * structure associated with the given cipher type.
408 *
409 * \param cipher_type Type of the cipher to search for.
410 *
411 * \return The cipher information structure associated with the
412 * given \p cipher_type.
413 * \return \c NULL if the associated cipher information is not found.
414 */
415 const mbedtls_cipher_info_t *mbedtls_cipher_info_from_type(const mbedtls_cipher_type_t cipher_type);
416
417 /**
418 * \brief This function retrieves the cipher-information
419 * structure associated with the given cipher ID,
420 * key size and mode.
421 *
422 * \param cipher_id The ID of the cipher to search for. For example,
423 * #MBEDTLS_CIPHER_ID_AES.
424 * \param key_bitlen The length of the key in bits.
425 * \param mode The cipher mode. For example, #MBEDTLS_MODE_CBC.
426 *
427 * \return The cipher information structure associated with the
428 * given \p cipher_id.
429 * \return \c NULL if the associated cipher information is not found.
430 */
431 const mbedtls_cipher_info_t *mbedtls_cipher_info_from_values(const mbedtls_cipher_id_t cipher_id,
432 int key_bitlen,
433 const mbedtls_cipher_mode_t mode);
434
435 /**
436 * \brief Retrieve the identifier for a cipher info structure.
437 *
438 * \param[in] info The cipher info structure to query.
439 * This may be \c NULL.
440 *
441 * \return The full cipher identifier (\c MBEDTLS_CIPHER_xxx).
442 * \return #MBEDTLS_CIPHER_NONE if \p info is \c NULL.
443 */
mbedtls_cipher_info_get_type(const mbedtls_cipher_info_t * info)444 static inline mbedtls_cipher_type_t mbedtls_cipher_info_get_type(
445 const mbedtls_cipher_info_t *info)
446 {
447 if (info == NULL) {
448 return MBEDTLS_CIPHER_NONE;
449 } else {
450 return (mbedtls_cipher_type_t) info->MBEDTLS_PRIVATE(type);
451 }
452 }
453
454 /**
455 * \brief Retrieve the operation mode for a cipher info structure.
456 *
457 * \param[in] info The cipher info structure to query.
458 * This may be \c NULL.
459 *
460 * \return The cipher mode (\c MBEDTLS_MODE_xxx).
461 * \return #MBEDTLS_MODE_NONE if \p info is \c NULL.
462 */
mbedtls_cipher_info_get_mode(const mbedtls_cipher_info_t * info)463 static inline mbedtls_cipher_mode_t mbedtls_cipher_info_get_mode(
464 const mbedtls_cipher_info_t *info)
465 {
466 if (info == NULL) {
467 return MBEDTLS_MODE_NONE;
468 } else {
469 return (mbedtls_cipher_mode_t) info->MBEDTLS_PRIVATE(mode);
470 }
471 }
472
473 /**
474 * \brief Retrieve the key size for a cipher info structure.
475 *
476 * \param[in] info The cipher info structure to query.
477 * This may be \c NULL.
478 *
479 * \return The key length in bits.
480 * For variable-sized ciphers, this is the default length.
481 * For DES, this includes the parity bits.
482 * \return \c 0 if \p info is \c NULL.
483 */
mbedtls_cipher_info_get_key_bitlen(const mbedtls_cipher_info_t * info)484 static inline size_t mbedtls_cipher_info_get_key_bitlen(
485 const mbedtls_cipher_info_t *info)
486 {
487 if (info == NULL) {
488 return 0;
489 } else {
490 return ((size_t) info->MBEDTLS_PRIVATE(key_bitlen)) << MBEDTLS_KEY_BITLEN_SHIFT;
491 }
492 }
493
494 /**
495 * \brief Retrieve the human-readable name for a
496 * cipher info structure.
497 *
498 * \param[in] info The cipher info structure to query.
499 * This may be \c NULL.
500 *
501 * \return The cipher name, which is a human readable string,
502 * with static storage duration.
503 * \return \c NULL if \p info is \c NULL.
504 */
mbedtls_cipher_info_get_name(const mbedtls_cipher_info_t * info)505 static inline const char *mbedtls_cipher_info_get_name(
506 const mbedtls_cipher_info_t *info)
507 {
508 if (info == NULL) {
509 return NULL;
510 } else {
511 return info->MBEDTLS_PRIVATE(name);
512 }
513 }
514
515 /**
516 * \brief This function returns the size of the IV or nonce
517 * for the cipher info structure, in bytes.
518 *
519 * \param info The cipher info structure. This may be \c NULL.
520 *
521 * \return The recommended IV size.
522 * \return \c 0 for ciphers not using an IV or a nonce.
523 * \return \c 0 if \p info is \c NULL.
524 */
mbedtls_cipher_info_get_iv_size(const mbedtls_cipher_info_t * info)525 static inline size_t mbedtls_cipher_info_get_iv_size(
526 const mbedtls_cipher_info_t *info)
527 {
528 if (info == NULL) {
529 return 0;
530 }
531
532 return ((size_t) info->MBEDTLS_PRIVATE(iv_size)) << MBEDTLS_IV_SIZE_SHIFT;
533 }
534
535 /**
536 * \brief This function returns the block size of the given
537 * cipher info structure in bytes.
538 *
539 * \param info The cipher info structure. This may be \c NULL.
540 *
541 * \return The block size of the cipher.
542 * \return \c 1 if the cipher is a stream cipher.
543 * \return \c 0 if \p info is \c NULL.
544 */
mbedtls_cipher_info_get_block_size(const mbedtls_cipher_info_t * info)545 static inline size_t mbedtls_cipher_info_get_block_size(
546 const mbedtls_cipher_info_t *info)
547 {
548 if (info == NULL) {
549 return 0;
550 }
551
552 return (size_t) (info->MBEDTLS_PRIVATE(block_size));
553 }
554
555 /**
556 * \brief This function returns a non-zero value if the key length for
557 * the given cipher is variable.
558 *
559 * \param info The cipher info structure. This may be \c NULL.
560 *
561 * \return Non-zero if the key length is variable, \c 0 otherwise.
562 * \return \c 0 if the given pointer is \c NULL.
563 */
mbedtls_cipher_info_has_variable_key_bitlen(const mbedtls_cipher_info_t * info)564 static inline int mbedtls_cipher_info_has_variable_key_bitlen(
565 const mbedtls_cipher_info_t *info)
566 {
567 if (info == NULL) {
568 return 0;
569 }
570
571 return info->MBEDTLS_PRIVATE(flags) & MBEDTLS_CIPHER_VARIABLE_KEY_LEN;
572 }
573
574 /**
575 * \brief This function returns a non-zero value if the IV size for
576 * the given cipher is variable.
577 *
578 * \param info The cipher info structure. This may be \c NULL.
579 *
580 * \return Non-zero if the IV size is variable, \c 0 otherwise.
581 * \return \c 0 if the given pointer is \c NULL.
582 */
mbedtls_cipher_info_has_variable_iv_size(const mbedtls_cipher_info_t * info)583 static inline int mbedtls_cipher_info_has_variable_iv_size(
584 const mbedtls_cipher_info_t *info)
585 {
586 if (info == NULL) {
587 return 0;
588 }
589
590 return info->MBEDTLS_PRIVATE(flags) & MBEDTLS_CIPHER_VARIABLE_IV_LEN;
591 }
592
593 /**
594 * \brief This function initializes a \p ctx as NONE.
595 *
596 * \param ctx The context to be initialized. This must not be \c NULL.
597 */
598 void mbedtls_cipher_init(mbedtls_cipher_context_t *ctx);
599
600 /**
601 * \brief This function frees and clears the cipher-specific
602 * context of \p ctx. Freeing \p ctx itself remains the
603 * responsibility of the caller.
604 *
605 * \param ctx The context to be freed. If this is \c NULL, the
606 * function has no effect, otherwise this must point to an
607 * initialized context.
608 */
609 void mbedtls_cipher_free(mbedtls_cipher_context_t *ctx);
610
611 /**
612 * \brief Clone the state of an cipher context
613 *
614 * \note The two contexts must have been setup to the same type
615 * (cloning from AES to DES make no sense).
616 *
617 * \param dst The destination context
618 * \param src The context to be cloned
619 *
620 * \return \c 0 on success,
621 * \c MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on parameter failure.
622 */
623 int mbedtls_cipher_clone(mbedtls_cipher_context_t *dst,
624 const mbedtls_cipher_context_t *src);
625
626 /**
627 * \brief This function prepares a cipher context for
628 * use with the given cipher primitive.
629 *
630 * \note After calling this function, you should call
631 * mbedtls_cipher_setkey() and, if the mode uses padding,
632 * mbedtls_cipher_set_padding_mode(), then for each
633 * message to encrypt or decrypt with this key, either:
634 * - mbedtls_cipher_crypt() for one-shot processing with
635 * non-AEAD modes;
636 * - mbedtls_cipher_auth_encrypt_ext() or
637 * mbedtls_cipher_auth_decrypt_ext() for one-shot
638 * processing with AEAD modes or NIST_KW;
639 * - for multi-part processing, see the documentation of
640 * mbedtls_cipher_reset().
641 *
642 * \param ctx The context to prepare. This must be initialized by
643 * a call to mbedtls_cipher_init() first.
644 * \param cipher_info The cipher to use.
645 *
646 * \return \c 0 on success.
647 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
648 * parameter-verification failure.
649 * \return #MBEDTLS_ERR_CIPHER_ALLOC_FAILED if allocation of the
650 * cipher-specific context fails.
651 */
652 int mbedtls_cipher_setup(mbedtls_cipher_context_t *ctx,
653 const mbedtls_cipher_info_t *cipher_info);
654
655 #if defined(MBEDTLS_USE_PSA_CRYPTO)
656 #if !defined(MBEDTLS_DEPRECATED_REMOVED)
657 /**
658 * \brief This function initializes a cipher context for
659 * PSA-based use with the given cipher primitive.
660 *
661 * \deprecated This function is deprecated and will be removed in a
662 * future version of the library.
663 * Please use psa_aead_xxx() / psa_cipher_xxx() directly
664 * instead.
665 *
666 * \note See #MBEDTLS_USE_PSA_CRYPTO for information on PSA.
667 *
668 * \param ctx The context to initialize. May not be \c NULL.
669 * \param cipher_info The cipher to use.
670 * \param taglen For AEAD ciphers, the length in bytes of the
671 * authentication tag to use. Subsequent uses of
672 * mbedtls_cipher_auth_encrypt_ext() or
673 * mbedtls_cipher_auth_decrypt_ext() must provide
674 * the same tag length.
675 * For non-AEAD ciphers, the value must be \c 0.
676 *
677 * \return \c 0 on success.
678 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
679 * parameter-verification failure.
680 * \return #MBEDTLS_ERR_CIPHER_ALLOC_FAILED if allocation of the
681 * cipher-specific context fails.
682 */
683 int MBEDTLS_DEPRECATED mbedtls_cipher_setup_psa(mbedtls_cipher_context_t *ctx,
684 const mbedtls_cipher_info_t *cipher_info,
685 size_t taglen);
686 #endif /* MBEDTLS_DEPRECATED_REMOVED */
687 #endif /* MBEDTLS_USE_PSA_CRYPTO */
688
689 /**
690 * \brief setup the cipher info structure.
691 *
692 * \param ctx cipher's context. Must have been initialised.
693 * \param cipher_info cipher to use.
694 *
695 * \return 0 on success,
696 * MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on parameter failure
697 */
698 int mbedtls_cipher_setup_info(mbedtls_cipher_context_t *ctx,
699 const mbedtls_cipher_info_t *cipher_info);
700
701 /**
702 * \brief This function returns the block size of the given cipher
703 * in bytes.
704 *
705 * \param ctx The context of the cipher.
706 *
707 * \return The block size of the underlying cipher.
708 * \return \c 1 if the cipher is a stream cipher.
709 * \return \c 0 if \p ctx has not been initialized.
710 */
mbedtls_cipher_get_block_size(const mbedtls_cipher_context_t * ctx)711 static inline unsigned int mbedtls_cipher_get_block_size(
712 const mbedtls_cipher_context_t *ctx)
713 {
714 if (ctx->MBEDTLS_PRIVATE(cipher_info) == NULL) {
715 return 0;
716 }
717
718 return (unsigned int) ctx->MBEDTLS_PRIVATE(cipher_info)->MBEDTLS_PRIVATE(block_size);
719 }
720
721 /**
722 * \brief This function returns the mode of operation for
723 * the cipher. For example, MBEDTLS_MODE_CBC.
724 *
725 * \param ctx The context of the cipher. This must be initialized.
726 *
727 * \return The mode of operation.
728 * \return #MBEDTLS_MODE_NONE if \p ctx has not been initialized.
729 */
mbedtls_cipher_get_cipher_mode(const mbedtls_cipher_context_t * ctx)730 static inline mbedtls_cipher_mode_t mbedtls_cipher_get_cipher_mode(
731 const mbedtls_cipher_context_t *ctx)
732 {
733 if (ctx->MBEDTLS_PRIVATE(cipher_info) == NULL) {
734 return MBEDTLS_MODE_NONE;
735 }
736
737 return (mbedtls_cipher_mode_t) ctx->MBEDTLS_PRIVATE(cipher_info)->MBEDTLS_PRIVATE(mode);
738 }
739
740 /**
741 * \brief This function returns the size of the IV or nonce
742 * of the cipher, in Bytes.
743 *
744 * \param ctx The context of the cipher. This must be initialized.
745 *
746 * \return The recommended IV size if no IV has been set.
747 * \return \c 0 for ciphers not using an IV or a nonce.
748 * \return The actual size if an IV has been set.
749 */
mbedtls_cipher_get_iv_size(const mbedtls_cipher_context_t * ctx)750 static inline int mbedtls_cipher_get_iv_size(
751 const mbedtls_cipher_context_t *ctx)
752 {
753 if (ctx->MBEDTLS_PRIVATE(cipher_info) == NULL) {
754 return 0;
755 }
756
757 if (ctx->MBEDTLS_PRIVATE(iv_size) != 0) {
758 return (int) ctx->MBEDTLS_PRIVATE(iv_size);
759 }
760
761 return (int) (((int) ctx->MBEDTLS_PRIVATE(cipher_info)->MBEDTLS_PRIVATE(iv_size)) <<
762 MBEDTLS_IV_SIZE_SHIFT);
763 }
764
765 /**
766 * \brief This function returns the type of the given cipher.
767 *
768 * \param ctx The context of the cipher. This must be initialized.
769 *
770 * \return The type of the cipher.
771 * \return #MBEDTLS_CIPHER_NONE if \p ctx has not been initialized.
772 */
mbedtls_cipher_get_type(const mbedtls_cipher_context_t * ctx)773 static inline mbedtls_cipher_type_t mbedtls_cipher_get_type(
774 const mbedtls_cipher_context_t *ctx)
775 {
776 if (ctx->MBEDTLS_PRIVATE(cipher_info) == NULL) {
777 return MBEDTLS_CIPHER_NONE;
778 }
779
780 return (mbedtls_cipher_type_t) ctx->MBEDTLS_PRIVATE(cipher_info)->MBEDTLS_PRIVATE(type);
781 }
782
783 /**
784 * \brief This function returns the name of the given cipher
785 * as a string.
786 *
787 * \param ctx The context of the cipher. This must be initialized.
788 *
789 * \return The name of the cipher.
790 * \return NULL if \p ctx has not been not initialized.
791 */
mbedtls_cipher_get_name(const mbedtls_cipher_context_t * ctx)792 static inline const char *mbedtls_cipher_get_name(
793 const mbedtls_cipher_context_t *ctx)
794 {
795 if (ctx->MBEDTLS_PRIVATE(cipher_info) == NULL) {
796 return 0;
797 }
798
799 return ctx->MBEDTLS_PRIVATE(cipher_info)->MBEDTLS_PRIVATE(name);
800 }
801
802 /**
803 * \brief This function returns the key length of the cipher.
804 *
805 * \param ctx The context of the cipher. This must be initialized.
806 *
807 * \return The key length of the cipher in bits.
808 * \return #MBEDTLS_KEY_LENGTH_NONE if \p ctx has not been
809 * initialized.
810 */
mbedtls_cipher_get_key_bitlen(const mbedtls_cipher_context_t * ctx)811 static inline int mbedtls_cipher_get_key_bitlen(
812 const mbedtls_cipher_context_t *ctx)
813 {
814 if (ctx->MBEDTLS_PRIVATE(cipher_info) == NULL) {
815 return MBEDTLS_KEY_LENGTH_NONE;
816 }
817
818 return (int) ctx->MBEDTLS_PRIVATE(cipher_info)->MBEDTLS_PRIVATE(key_bitlen) <<
819 MBEDTLS_KEY_BITLEN_SHIFT;
820 }
821
822 /**
823 * \brief This function returns the operation of the given cipher.
824 *
825 * \param ctx The context of the cipher. This must be initialized.
826 *
827 * \return The type of operation: #MBEDTLS_ENCRYPT or #MBEDTLS_DECRYPT.
828 * \return #MBEDTLS_OPERATION_NONE if \p ctx has not been initialized.
829 */
mbedtls_cipher_get_operation(const mbedtls_cipher_context_t * ctx)830 static inline mbedtls_operation_t mbedtls_cipher_get_operation(
831 const mbedtls_cipher_context_t *ctx)
832 {
833 if (ctx->MBEDTLS_PRIVATE(cipher_info) == NULL) {
834 return MBEDTLS_OPERATION_NONE;
835 }
836
837 return ctx->MBEDTLS_PRIVATE(operation);
838 }
839
840 /**
841 * \brief This function sets the key to use with the given context.
842 *
843 * \param ctx The generic cipher context. This must be initialized and
844 * bound to a cipher information structure.
845 * \param key The key to use. This must be a readable buffer of at
846 * least \p key_bitlen Bits.
847 * \param key_bitlen The key length to use, in Bits.
848 * \param operation The operation that the key will be used for:
849 * #MBEDTLS_ENCRYPT or #MBEDTLS_DECRYPT.
850 *
851 * \return \c 0 on success.
852 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
853 * parameter-verification failure.
854 * \return A cipher-specific error code on failure.
855 */
856 int mbedtls_cipher_setkey(mbedtls_cipher_context_t *ctx,
857 const unsigned char *key,
858 int key_bitlen,
859 const mbedtls_operation_t operation);
860
861 #if defined(MBEDTLS_CIPHER_MODE_WITH_PADDING)
862 /**
863 * \brief This function sets the padding mode, for cipher modes
864 * that use padding.
865 *
866 *
867 * \param ctx The generic cipher context. This must be initialized and
868 * bound to a cipher information structure.
869 * \param mode The padding mode.
870 *
871 * \return \c 0 on success.
872 * \return #MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE
873 * if the selected padding mode is not supported.
874 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA if the cipher mode
875 * does not support padding.
876 */
877 int mbedtls_cipher_set_padding_mode(mbedtls_cipher_context_t *ctx,
878 mbedtls_cipher_padding_t mode);
879 #endif /* MBEDTLS_CIPHER_MODE_WITH_PADDING */
880
881 /**
882 * \brief This function sets the initialization vector (IV)
883 * or nonce.
884 *
885 * \note Some ciphers do not use IVs nor nonce. For these
886 * ciphers, this function has no effect.
887 *
888 * \note For #MBEDTLS_CIPHER_CHACHA20, the nonce length must
889 * be 12, and the initial counter value is 0.
890 *
891 * \note For #MBEDTLS_CIPHER_CHACHA20_POLY1305, the nonce length
892 * must be 12.
893 *
894 * \param ctx The generic cipher context. This must be initialized and
895 * bound to a cipher information structure.
896 * \param iv The IV to use, or NONCE_COUNTER for CTR-mode ciphers. This
897 * must be a readable buffer of at least \p iv_len Bytes.
898 * \param iv_len The IV length for ciphers with variable-size IV.
899 * This parameter is discarded by ciphers with fixed-size IV.
900 *
901 * \return \c 0 on success.
902 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
903 * parameter-verification failure.
904 */
905 int mbedtls_cipher_set_iv(mbedtls_cipher_context_t *ctx,
906 const unsigned char *iv,
907 size_t iv_len);
908
909 /**
910 * \brief This function resets the cipher state.
911 *
912 * \note With non-AEAD ciphers, the order of calls for each message
913 * is as follows:
914 * 1. mbedtls_cipher_set_iv() if the mode uses an IV/nonce;
915 * 2. mbedtls_cipher_reset();
916 * 3. mbedtls_cipher_update() zero, one or more times;
917 * 4. mbedtls_cipher_finish_padded() (recommended for decryption
918 * if the mode uses padding) or mbedtls_cipher_finish().
919 * .
920 * This sequence can be repeated to encrypt or decrypt multiple
921 * messages with the same key.
922 *
923 * \note With AEAD ciphers, the order of calls for each message
924 * is as follows:
925 * 1. mbedtls_cipher_set_iv() if the mode uses an IV/nonce;
926 * 2. mbedtls_cipher_reset();
927 * 3. mbedtls_cipher_update_ad();
928 * 4. mbedtls_cipher_update() zero, one or more times;
929 * 5. mbedtls_cipher_finish() (or mbedtls_cipher_finish_padded());
930 * 6. mbedtls_cipher_check_tag() (for decryption) or
931 * mbedtls_cipher_write_tag() (for encryption).
932 * .
933 * This sequence can be repeated to encrypt or decrypt multiple
934 * messages with the same key.
935 *
936 * \param ctx The generic cipher context. This must be bound to a key.
937 *
938 * \return \c 0 on success.
939 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
940 * parameter-verification failure.
941 */
942 int mbedtls_cipher_reset(mbedtls_cipher_context_t *ctx);
943
944 #if defined(MBEDTLS_GCM_C) || defined(MBEDTLS_CHACHAPOLY_C)
945 /**
946 * \brief This function adds additional data for AEAD ciphers.
947 * Currently supported with GCM and ChaCha20+Poly1305.
948 *
949 * \param ctx The generic cipher context. This must be initialized.
950 * \param ad The additional data to use. This must be a readable
951 * buffer of at least \p ad_len Bytes.
952 * \param ad_len The length of \p ad in Bytes.
953 *
954 * \return \c 0 on success.
955 * \return A specific error code on failure.
956 */
957 int mbedtls_cipher_update_ad(mbedtls_cipher_context_t *ctx,
958 const unsigned char *ad, size_t ad_len);
959 #endif /* MBEDTLS_GCM_C || MBEDTLS_CHACHAPOLY_C */
960
961 /**
962 * \brief The generic cipher update function. It encrypts or
963 * decrypts using the given cipher context. Writes as
964 * many block-sized blocks of data as possible to output.
965 * Any data that cannot be written immediately is either
966 * added to the next block, or flushed when
967 * mbedtls_cipher_finish() or mbedtls_cipher_finish_padded()
968 * is called.
969 * Exception: For MBEDTLS_MODE_ECB, expects a single block
970 * in size. For example, 16 Bytes for AES.
971 *
972 * \param ctx The generic cipher context. This must be initialized and
973 * bound to a key.
974 * \param input The buffer holding the input data. This must be a
975 * readable buffer of at least \p ilen Bytes.
976 * \param ilen The length of the input data.
977 * \param output The buffer for the output data. This must be able to
978 * hold at least `ilen + block_size`. This must not be the
979 * same buffer as \p input.
980 * \param olen The length of the output data, to be updated with the
981 * actual number of Bytes written. This must not be
982 * \c NULL.
983 *
984 * \return \c 0 on success.
985 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
986 * parameter-verification failure.
987 * \return #MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE on an
988 * unsupported mode for a cipher.
989 * \return A cipher-specific error code on failure.
990 */
991 int mbedtls_cipher_update(mbedtls_cipher_context_t *ctx,
992 const unsigned char *input,
993 size_t ilen, unsigned char *output,
994 size_t *olen);
995
996 /**
997 * \brief The generic cipher finalization function. If data still
998 * needs to be flushed from an incomplete block, the data
999 * contained in it is padded to the size of
1000 * the last block, and written to the \p output buffer.
1001 *
1002 * \warning This function reports invalid padding through an error
1003 * code. Adversaries may be able to decrypt encrypted
1004 * data if they can submit chosen ciphertexts and
1005 * detect whether it has valid padding or not,
1006 * either through direct observation or through a side
1007 * channel such as timing. This is known as a
1008 * padding oracle attack.
1009 * Therefore applications that call this function for
1010 * decryption with a cipher that involves padding
1011 * should take care around error handling. Preferably,
1012 * such applications should use
1013 * mbedtls_cipher_finish_padded() instead of this function.
1014 *
1015 * \param ctx The generic cipher context. This must be initialized and
1016 * bound to a key.
1017 * \param output The buffer to write data to. This needs to be a writable
1018 * buffer of at least block_size Bytes.
1019 * \param olen The length of the data written to the \p output buffer.
1020 * This may not be \c NULL.
1021 * Note that when decrypting in a mode with padding,
1022 * the actual output length is sensitive and may be
1023 * used to mount a padding oracle attack (see warning
1024 * above), although less efficiently than through
1025 * the invalid-padding condition.
1026 *
1027 * \return \c 0 on success.
1028 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
1029 * parameter-verification failure.
1030 * \return #MBEDTLS_ERR_CIPHER_FULL_BLOCK_EXPECTED on decryption
1031 * expecting a full block but not receiving one.
1032 * \return #MBEDTLS_ERR_CIPHER_INVALID_PADDING on invalid padding
1033 * while decrypting. Note that invalid-padding errors
1034 * should be handled carefully; see the warning above.
1035 * \return A cipher-specific error code on failure.
1036 */
1037 int mbedtls_cipher_finish(mbedtls_cipher_context_t *ctx,
1038 unsigned char *output, size_t *olen);
1039
1040 /**
1041 * \brief The generic cipher finalization function. If data still
1042 * needs to be flushed from an incomplete block, the data
1043 * contained in it is padded to the size of
1044 * the last block, and written to the \p output buffer.
1045 *
1046 * \note This function is similar to mbedtls_cipher_finish().
1047 * The only difference is that it reports invalid padding
1048 * decryption differently, through the \p invalid_padding
1049 * parameter rather than an error code.
1050 * For encryption, and in modes without padding (including
1051 * all authenticated modes), this function is identical
1052 * to mbedtls_cipher_finish().
1053 *
1054 * \param[in,out] ctx The generic cipher context. This must be initialized and
1055 * bound to a key.
1056 * \param[out] output The buffer to write data to. This needs to be a writable
1057 * buffer of at least block_size Bytes.
1058 * \param[out] olen The length of the data written to the \p output buffer.
1059 * This may not be \c NULL.
1060 * Note that when decrypting in a mode with padding,
1061 * the actual output length is sensitive and may be
1062 * used to mount a padding oracle attack (see warning
1063 * on mbedtls_cipher_finish()).
1064 * \param[out] invalid_padding
1065 * If this function returns \c 0 on decryption,
1066 * \p *invalid_padding is \c 0 if the ciphertext was
1067 * valid, and all-bits-one if the ciphertext had invalid
1068 * padding.
1069 * On encryption, or in a mode without padding (including
1070 * all authenticated modes), \p *invalid_padding is \c 0
1071 * on success.
1072 * The value in \p *invalid_padding is unspecified if
1073 * this function returns a nonzero status.
1074 *
1075 * \return \c 0 on success.
1076 * Also \c 0 for decryption with invalid padding.
1077 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
1078 * parameter-verification failure.
1079 * \return #MBEDTLS_ERR_CIPHER_FULL_BLOCK_EXPECTED on decryption
1080 * expecting a full block but not receiving one.
1081 * \return A cipher-specific error code on failure.
1082 */
1083 int mbedtls_cipher_finish_padded(mbedtls_cipher_context_t *ctx,
1084 unsigned char *output, size_t *olen,
1085 size_t *invalid_padding);
1086
1087 #if defined(MBEDTLS_GCM_C) || defined(MBEDTLS_CHACHAPOLY_C)
1088 /**
1089 * \brief This function writes a tag for AEAD ciphers.
1090 * Currently supported with GCM and ChaCha20+Poly1305.
1091 * This must be called after mbedtls_cipher_finish()
1092 * or mbedtls_cipher_finish_padded().
1093 *
1094 * \param ctx The generic cipher context. This must be initialized,
1095 * bound to a key, and have just completed a cipher
1096 * operation through mbedtls_cipher_finish() the tag for
1097 * which should be written.
1098 * \param tag The buffer to write the tag to. This must be a writable
1099 * buffer of at least \p tag_len Bytes.
1100 * \param tag_len The length of the tag to write.
1101 *
1102 * \return \c 0 on success.
1103 * \return A specific error code on failure.
1104 */
1105 int mbedtls_cipher_write_tag(mbedtls_cipher_context_t *ctx,
1106 unsigned char *tag, size_t tag_len);
1107
1108 /**
1109 * \brief This function checks the tag for AEAD ciphers.
1110 * Currently supported with GCM and ChaCha20+Poly1305.
1111 * This must be called after mbedtls_cipher_finish()
1112 * or mbedtls_cipher_finish_padded().
1113 *
1114 * \param ctx The generic cipher context. This must be initialized.
1115 * \param tag The buffer holding the tag. This must be a readable
1116 * buffer of at least \p tag_len Bytes.
1117 * \param tag_len The length of the tag to check.
1118 *
1119 * \return \c 0 on success.
1120 * \return A specific error code on failure.
1121 */
1122 int mbedtls_cipher_check_tag(mbedtls_cipher_context_t *ctx,
1123 const unsigned char *tag, size_t tag_len);
1124 #endif /* MBEDTLS_GCM_C || MBEDTLS_CHACHAPOLY_C */
1125
1126 /**
1127 * \brief The generic all-in-one encryption/decryption function,
1128 * for all ciphers except AEAD constructs.
1129 *
1130 * \param ctx The generic cipher context. This must be initialized.
1131 * \param iv The IV to use, or NONCE_COUNTER for CTR-mode ciphers.
1132 * This must be a readable buffer of at least \p iv_len
1133 * Bytes.
1134 * \param iv_len The IV length for ciphers with variable-size IV.
1135 * This parameter is discarded by ciphers with fixed-size
1136 * IV.
1137 * \param input The buffer holding the input data. This must be a
1138 * readable buffer of at least \p ilen Bytes.
1139 * \param ilen The length of the input data in Bytes.
1140 * \param output The buffer for the output data. This must be able to
1141 * hold at least `ilen + block_size`. This must not be the
1142 * same buffer as \p input.
1143 * \param olen The length of the output data, to be updated with the
1144 * actual number of Bytes written. This must not be
1145 * \c NULL.
1146 *
1147 * \note Some ciphers do not use IVs nor nonce. For these
1148 * ciphers, use \p iv = NULL and \p iv_len = 0.
1149 *
1150 * \return \c 0 on success.
1151 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
1152 * parameter-verification failure.
1153 * \return #MBEDTLS_ERR_CIPHER_FULL_BLOCK_EXPECTED on decryption
1154 * expecting a full block but not receiving one.
1155 * \return #MBEDTLS_ERR_CIPHER_INVALID_PADDING on invalid padding
1156 * while decrypting.
1157 * \return A cipher-specific error code on failure.
1158 */
1159 int mbedtls_cipher_crypt(mbedtls_cipher_context_t *ctx,
1160 const unsigned char *iv, size_t iv_len,
1161 const unsigned char *input, size_t ilen,
1162 unsigned char *output, size_t *olen);
1163
1164 #if defined(MBEDTLS_CIPHER_MODE_AEAD) || defined(MBEDTLS_NIST_KW_C)
1165 /**
1166 * \brief The authenticated encryption (AEAD/NIST_KW) function.
1167 *
1168 * \note For AEAD modes, the tag will be appended to the
1169 * ciphertext, as recommended by RFC 5116.
1170 * (NIST_KW doesn't have a separate tag.)
1171 *
1172 * \param ctx The generic cipher context. This must be initialized and
1173 * bound to a key, with an AEAD algorithm or NIST_KW.
1174 * \param iv The nonce to use. This must be a readable buffer of
1175 * at least \p iv_len Bytes and may be \c NULL if \p
1176 * iv_len is \c 0.
1177 * \param iv_len The length of the nonce. For AEAD ciphers, this must
1178 * satisfy the constraints imposed by the cipher used.
1179 * For NIST_KW, this must be \c 0.
1180 * \param ad The additional data to authenticate. This must be a
1181 * readable buffer of at least \p ad_len Bytes, and may
1182 * be \c NULL is \p ad_len is \c 0.
1183 * \param ad_len The length of \p ad. For NIST_KW, this must be \c 0.
1184 * \param input The buffer holding the input data. This must be a
1185 * readable buffer of at least \p ilen Bytes, and may be
1186 * \c NULL if \p ilen is \c 0.
1187 * \param ilen The length of the input data.
1188 * \param output The buffer for the output data. This must be a
1189 * writable buffer of at least \p output_len Bytes, and
1190 * must not be \c NULL.
1191 * \param output_len The length of the \p output buffer in Bytes. For AEAD
1192 * ciphers, this must be at least \p ilen + \p tag_len.
1193 * For NIST_KW, this must be at least \p ilen + 8
1194 * (rounded up to a multiple of 8 if KWP is used);
1195 * \p ilen + 15 is always a safe value.
1196 * \param olen This will be filled with the actual number of Bytes
1197 * written to the \p output buffer. This must point to a
1198 * writable object of type \c size_t.
1199 * \param tag_len The desired length of the authentication tag. For AEAD
1200 * ciphers, this must match the constraints imposed by
1201 * the cipher used, and in particular must not be \c 0.
1202 * For NIST_KW, this must be \c 0.
1203 *
1204 * \return \c 0 on success.
1205 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
1206 * parameter-verification failure.
1207 * \return A cipher-specific error code on failure.
1208 */
1209 int mbedtls_cipher_auth_encrypt_ext(mbedtls_cipher_context_t *ctx,
1210 const unsigned char *iv, size_t iv_len,
1211 const unsigned char *ad, size_t ad_len,
1212 const unsigned char *input, size_t ilen,
1213 unsigned char *output, size_t output_len,
1214 size_t *olen, size_t tag_len);
1215
1216 /**
1217 * \brief The authenticated encryption (AEAD/NIST_KW) function.
1218 *
1219 * \note If the data is not authentic, then the output buffer
1220 * is zeroed out to prevent the unauthentic plaintext being
1221 * used, making this interface safer.
1222 *
1223 * \note For AEAD modes, the tag must be appended to the
1224 * ciphertext, as recommended by RFC 5116.
1225 * (NIST_KW doesn't have a separate tag.)
1226 *
1227 * \param ctx The generic cipher context. This must be initialized and
1228 * bound to a key, with an AEAD algorithm or NIST_KW.
1229 * \param iv The nonce to use. This must be a readable buffer of
1230 * at least \p iv_len Bytes and may be \c NULL if \p
1231 * iv_len is \c 0.
1232 * \param iv_len The length of the nonce. For AEAD ciphers, this must
1233 * satisfy the constraints imposed by the cipher used.
1234 * For NIST_KW, this must be \c 0.
1235 * \param ad The additional data to authenticate. This must be a
1236 * readable buffer of at least \p ad_len Bytes, and may
1237 * be \c NULL is \p ad_len is \c 0.
1238 * \param ad_len The length of \p ad. For NIST_KW, this must be \c 0.
1239 * \param input The buffer holding the input data. This must be a
1240 * readable buffer of at least \p ilen Bytes, and may be
1241 * \c NULL if \p ilen is \c 0.
1242 * \param ilen The length of the input data. For AEAD ciphers this
1243 * must be at least \p tag_len. For NIST_KW this must be
1244 * at least \c 8.
1245 * \param output The buffer for the output data. This must be a
1246 * writable buffer of at least \p output_len Bytes, and
1247 * may be \c NULL if \p output_len is \c 0.
1248 * \param output_len The length of the \p output buffer in Bytes. For AEAD
1249 * ciphers, this must be at least \p ilen - \p tag_len.
1250 * For NIST_KW, this must be at least \p ilen - 8.
1251 * \param olen This will be filled with the actual number of Bytes
1252 * written to the \p output buffer. This must point to a
1253 * writable object of type \c size_t.
1254 * \param tag_len The actual length of the authentication tag. For AEAD
1255 * ciphers, this must match the constraints imposed by
1256 * the cipher used, and in particular must not be \c 0.
1257 * For NIST_KW, this must be \c 0.
1258 *
1259 * \return \c 0 on success.
1260 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
1261 * parameter-verification failure.
1262 * \return #MBEDTLS_ERR_CIPHER_AUTH_FAILED if data is not authentic.
1263 * \return A cipher-specific error code on failure.
1264 */
1265 int mbedtls_cipher_auth_decrypt_ext(mbedtls_cipher_context_t *ctx,
1266 const unsigned char *iv, size_t iv_len,
1267 const unsigned char *ad, size_t ad_len,
1268 const unsigned char *input, size_t ilen,
1269 unsigned char *output, size_t output_len,
1270 size_t *olen, size_t tag_len);
1271 #endif /* MBEDTLS_CIPHER_MODE_AEAD || MBEDTLS_NIST_KW_C */
1272 #ifdef __cplusplus
1273 }
1274 #endif
1275
1276 #endif /* MBEDTLS_CIPHER_H */
1277