1/**
2 * \file cipher.h
3 *
4 * \brief This file contains an abstraction interface for use with the cipher
5 * primitives provided by the library. It provides a common interface to all of
6 * the available cipher operations.
7 *
8 * \author Adriaan de Jong <dejong@fox-it.com>
9 */
10/*
11 * Copyright The Mbed TLS Contributors
12 * SPDX-License-Identifier: Apache-2.0
13 *
14 * Licensed under the Apache License, Version 2.0 (the "License"); you may
15 * not use this file except in compliance with the License.
16 * You may obtain a copy of the License at
17 *
18 * http://www.apache.org/licenses/LICENSE-2.0
19 *
20 * Unless required by applicable law or agreed to in writing, software
21 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
22 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
23 * See the License for the specific language governing permissions and
24 * limitations under the License.
25 */
26
27#ifndef MBEDTLS_CIPHER_H
28#define MBEDTLS_CIPHER_H
29
30#if !defined(MBEDTLS_CONFIG_FILE)
31#include "mbedtls/config.h"
32#else
33#include MBEDTLS_CONFIG_FILE
34#endif
35
36#include <stddef.h>
37#include "mbedtls/platform_util.h"
38
39#if defined(MBEDTLS_GCM_C) || defined(MBEDTLS_CCM_C) || defined(MBEDTLS_CHACHAPOLY_C)
40#define MBEDTLS_CIPHER_MODE_AEAD
41#endif
42
43#if defined(MBEDTLS_CIPHER_MODE_CBC)
44#define MBEDTLS_CIPHER_MODE_WITH_PADDING
45#endif
46
47#if defined(MBEDTLS_ARC4_C) || defined(MBEDTLS_CIPHER_NULL_CIPHER) || \
48 defined(MBEDTLS_CHACHA20_C)
49#define MBEDTLS_CIPHER_MODE_STREAM
50#endif
51
52#if (defined(__ARMCC_VERSION) || defined(_MSC_VER)) && \
53 !defined(inline) && !defined(__cplusplus)
54#define inline __inline
55#endif
56
57/** The selected feature is not available. */
58#define MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE -0x6080
59/** Bad input parameters. */
60#define MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA -0x6100
61/** Failed to allocate memory. */
62#define MBEDTLS_ERR_CIPHER_ALLOC_FAILED -0x6180
63/** Input data contains invalid padding and is rejected. */
64#define MBEDTLS_ERR_CIPHER_INVALID_PADDING -0x6200
65/** Decryption of block requires a full block. */
66#define MBEDTLS_ERR_CIPHER_FULL_BLOCK_EXPECTED -0x6280
67/** Authentication failed (for AEAD modes). */
68#define MBEDTLS_ERR_CIPHER_AUTH_FAILED -0x6300
69/** The context is invalid. For example, because it was freed. */
70#define MBEDTLS_ERR_CIPHER_INVALID_CONTEXT -0x6380
71
72/* MBEDTLS_ERR_CIPHER_HW_ACCEL_FAILED is deprecated and should not be used. */
73/** Cipher hardware accelerator failed. */
74#define MBEDTLS_ERR_CIPHER_HW_ACCEL_FAILED -0x6400
75
76#define MBEDTLS_CIPHER_VARIABLE_IV_LEN 0x01 /**< Cipher accepts IVs of variable length. */
77#define MBEDTLS_CIPHER_VARIABLE_KEY_LEN 0x02 /**< Cipher accepts keys of variable length. */
78
79#ifdef __cplusplus
80extern "C" {
81#endif
82
83/**
84 * \brief Supported cipher types.
85 *
86 * \warning RC4 and DES/3DES are considered weak ciphers and their use
87 * constitutes a security risk. We recommend considering stronger
88 * ciphers instead.
89 */
90typedef enum {
91 MBEDTLS_CIPHER_ID_NONE = 0, /**< Placeholder to mark the end of cipher ID lists. */
92 MBEDTLS_CIPHER_ID_NULL, /**< The identity cipher, treated as a stream cipher. */
93 MBEDTLS_CIPHER_ID_AES, /**< The AES cipher. */
94 MBEDTLS_CIPHER_ID_DES, /**< The DES cipher. \warning DES is considered weak. */
95 MBEDTLS_CIPHER_ID_3DES, /**< The Triple DES cipher. \warning 3DES is considered weak. */
96 MBEDTLS_CIPHER_ID_CAMELLIA, /**< The Camellia cipher. */
97 MBEDTLS_CIPHER_ID_BLOWFISH, /**< The Blowfish cipher. */
98 MBEDTLS_CIPHER_ID_ARC4, /**< The RC4 cipher. */
99 MBEDTLS_CIPHER_ID_ARIA, /**< The Aria cipher. */
100 MBEDTLS_CIPHER_ID_CHACHA20, /**< The ChaCha20 cipher. */
101} mbedtls_cipher_id_t;
102
103/**
104 * \brief Supported {cipher type, cipher mode} pairs.
105 *
106 * \warning RC4 and DES/3DES are considered weak ciphers and their use
107 * constitutes a security risk. We recommend considering stronger
108 * ciphers instead.
109 */
110typedef enum {
111 MBEDTLS_CIPHER_NONE = 0, /**< Placeholder to mark the end of cipher-pair lists. */
112 MBEDTLS_CIPHER_NULL, /**< The identity stream cipher. */
113 MBEDTLS_CIPHER_AES_128_ECB, /**< AES cipher with 128-bit ECB mode. */
114 MBEDTLS_CIPHER_AES_192_ECB, /**< AES cipher with 192-bit ECB mode. */
115 MBEDTLS_CIPHER_AES_256_ECB, /**< AES cipher with 256-bit ECB mode. */
116 MBEDTLS_CIPHER_AES_128_CBC, /**< AES cipher with 128-bit CBC mode. */
117 MBEDTLS_CIPHER_AES_192_CBC, /**< AES cipher with 192-bit CBC mode. */
118 MBEDTLS_CIPHER_AES_256_CBC, /**< AES cipher with 256-bit CBC mode. */
119 MBEDTLS_CIPHER_AES_128_CFB128, /**< AES cipher with 128-bit CFB128 mode. */
120 MBEDTLS_CIPHER_AES_192_CFB128, /**< AES cipher with 192-bit CFB128 mode. */
121 MBEDTLS_CIPHER_AES_256_CFB128, /**< AES cipher with 256-bit CFB128 mode. */
122 MBEDTLS_CIPHER_AES_128_CTR, /**< AES cipher with 128-bit CTR mode. */
123 MBEDTLS_CIPHER_AES_192_CTR, /**< AES cipher with 192-bit CTR mode. */
124 MBEDTLS_CIPHER_AES_256_CTR, /**< AES cipher with 256-bit CTR mode. */
125 MBEDTLS_CIPHER_AES_128_GCM, /**< AES cipher with 128-bit GCM mode. */
126 MBEDTLS_CIPHER_AES_192_GCM, /**< AES cipher with 192-bit GCM mode. */
127 MBEDTLS_CIPHER_AES_256_GCM, /**< AES cipher with 256-bit GCM mode. */
128 MBEDTLS_CIPHER_CAMELLIA_128_ECB, /**< Camellia cipher with 128-bit ECB mode. */
129 MBEDTLS_CIPHER_CAMELLIA_192_ECB, /**< Camellia cipher with 192-bit ECB mode. */
130 MBEDTLS_CIPHER_CAMELLIA_256_ECB, /**< Camellia cipher with 256-bit ECB mode. */
131 MBEDTLS_CIPHER_CAMELLIA_128_CBC, /**< Camellia cipher with 128-bit CBC mode. */
132 MBEDTLS_CIPHER_CAMELLIA_192_CBC, /**< Camellia cipher with 192-bit CBC mode. */
133 MBEDTLS_CIPHER_CAMELLIA_256_CBC, /**< Camellia cipher with 256-bit CBC mode. */
134 MBEDTLS_CIPHER_CAMELLIA_128_CFB128, /**< Camellia cipher with 128-bit CFB128 mode. */
135 MBEDTLS_CIPHER_CAMELLIA_192_CFB128, /**< Camellia cipher with 192-bit CFB128 mode. */
136 MBEDTLS_CIPHER_CAMELLIA_256_CFB128, /**< Camellia cipher with 256-bit CFB128 mode. */
137 MBEDTLS_CIPHER_CAMELLIA_128_CTR, /**< Camellia cipher with 128-bit CTR mode. */
138 MBEDTLS_CIPHER_CAMELLIA_192_CTR, /**< Camellia cipher with 192-bit CTR mode. */
139 MBEDTLS_CIPHER_CAMELLIA_256_CTR, /**< Camellia cipher with 256-bit CTR mode. */
140 MBEDTLS_CIPHER_CAMELLIA_128_GCM, /**< Camellia cipher with 128-bit GCM mode. */
141 MBEDTLS_CIPHER_CAMELLIA_192_GCM, /**< Camellia cipher with 192-bit GCM mode. */
142 MBEDTLS_CIPHER_CAMELLIA_256_GCM, /**< Camellia cipher with 256-bit GCM mode. */
143 MBEDTLS_CIPHER_DES_ECB, /**< DES cipher with ECB mode. \warning DES is considered weak. */
144 MBEDTLS_CIPHER_DES_CBC, /**< DES cipher with CBC mode. \warning DES is considered weak. */
145 MBEDTLS_CIPHER_DES_EDE_ECB, /**< DES cipher with EDE ECB mode. \warning 3DES is considered weak. */
146 MBEDTLS_CIPHER_DES_EDE_CBC, /**< DES cipher with EDE CBC mode. \warning 3DES is considered weak. */
147 MBEDTLS_CIPHER_DES_EDE3_ECB, /**< DES cipher with EDE3 ECB mode. \warning 3DES is considered weak. */
148 MBEDTLS_CIPHER_DES_EDE3_CBC, /**< DES cipher with EDE3 CBC mode. \warning 3DES is considered weak. */
149 MBEDTLS_CIPHER_BLOWFISH_ECB, /**< Blowfish cipher with ECB mode. */
150 MBEDTLS_CIPHER_BLOWFISH_CBC, /**< Blowfish cipher with CBC mode. */
151 MBEDTLS_CIPHER_BLOWFISH_CFB64, /**< Blowfish cipher with CFB64 mode. */
152 MBEDTLS_CIPHER_BLOWFISH_CTR, /**< Blowfish cipher with CTR mode. */
153 MBEDTLS_CIPHER_ARC4_128, /**< RC4 cipher with 128-bit mode. */
154 MBEDTLS_CIPHER_AES_128_CCM, /**< AES cipher with 128-bit CCM mode. */
155 MBEDTLS_CIPHER_AES_192_CCM, /**< AES cipher with 192-bit CCM mode. */
156 MBEDTLS_CIPHER_AES_256_CCM, /**< AES cipher with 256-bit CCM mode. */
157 MBEDTLS_CIPHER_CAMELLIA_128_CCM, /**< Camellia cipher with 128-bit CCM mode. */
158 MBEDTLS_CIPHER_CAMELLIA_192_CCM, /**< Camellia cipher with 192-bit CCM mode. */
159 MBEDTLS_CIPHER_CAMELLIA_256_CCM, /**< Camellia cipher with 256-bit CCM mode. */
160 MBEDTLS_CIPHER_ARIA_128_ECB, /**< Aria cipher with 128-bit key and ECB mode. */
161 MBEDTLS_CIPHER_ARIA_192_ECB, /**< Aria cipher with 192-bit key and ECB mode. */
162 MBEDTLS_CIPHER_ARIA_256_ECB, /**< Aria cipher with 256-bit key and ECB mode. */
163 MBEDTLS_CIPHER_ARIA_128_CBC, /**< Aria cipher with 128-bit key and CBC mode. */
164 MBEDTLS_CIPHER_ARIA_192_CBC, /**< Aria cipher with 192-bit key and CBC mode. */
165 MBEDTLS_CIPHER_ARIA_256_CBC, /**< Aria cipher with 256-bit key and CBC mode. */
166 MBEDTLS_CIPHER_ARIA_128_CFB128, /**< Aria cipher with 128-bit key and CFB-128 mode. */
167 MBEDTLS_CIPHER_ARIA_192_CFB128, /**< Aria cipher with 192-bit key and CFB-128 mode. */
168 MBEDTLS_CIPHER_ARIA_256_CFB128, /**< Aria cipher with 256-bit key and CFB-128 mode. */
169 MBEDTLS_CIPHER_ARIA_128_CTR, /**< Aria cipher with 128-bit key and CTR mode. */
170 MBEDTLS_CIPHER_ARIA_192_CTR, /**< Aria cipher with 192-bit key and CTR mode. */
171 MBEDTLS_CIPHER_ARIA_256_CTR, /**< Aria cipher with 256-bit key and CTR mode. */
172 MBEDTLS_CIPHER_ARIA_128_GCM, /**< Aria cipher with 128-bit key and GCM mode. */
173 MBEDTLS_CIPHER_ARIA_192_GCM, /**< Aria cipher with 192-bit key and GCM mode. */
174 MBEDTLS_CIPHER_ARIA_256_GCM, /**< Aria cipher with 256-bit key and GCM mode. */
175 MBEDTLS_CIPHER_ARIA_128_CCM, /**< Aria cipher with 128-bit key and CCM mode. */
176 MBEDTLS_CIPHER_ARIA_192_CCM, /**< Aria cipher with 192-bit key and CCM mode. */
177 MBEDTLS_CIPHER_ARIA_256_CCM, /**< Aria cipher with 256-bit key and CCM mode. */
178 MBEDTLS_CIPHER_AES_128_OFB, /**< AES 128-bit cipher in OFB mode. */
179 MBEDTLS_CIPHER_AES_192_OFB, /**< AES 192-bit cipher in OFB mode. */
180 MBEDTLS_CIPHER_AES_256_OFB, /**< AES 256-bit cipher in OFB mode. */
181 MBEDTLS_CIPHER_AES_128_XTS, /**< AES 128-bit cipher in XTS block mode. */
182 MBEDTLS_CIPHER_AES_256_XTS, /**< AES 256-bit cipher in XTS block mode. */
183 MBEDTLS_CIPHER_CHACHA20, /**< ChaCha20 stream cipher. */
184 MBEDTLS_CIPHER_CHACHA20_POLY1305, /**< ChaCha20-Poly1305 AEAD cipher. */
185 MBEDTLS_CIPHER_AES_128_KW, /**< AES cipher with 128-bit NIST KW mode. */
186 MBEDTLS_CIPHER_AES_192_KW, /**< AES cipher with 192-bit NIST KW mode. */
187 MBEDTLS_CIPHER_AES_256_KW, /**< AES cipher with 256-bit NIST KW mode. */
188 MBEDTLS_CIPHER_AES_128_KWP, /**< AES cipher with 128-bit NIST KWP mode. */
189 MBEDTLS_CIPHER_AES_192_KWP, /**< AES cipher with 192-bit NIST KWP mode. */
190 MBEDTLS_CIPHER_AES_256_KWP, /**< AES cipher with 256-bit NIST KWP mode. */
191} mbedtls_cipher_type_t;
192
193/** Supported cipher modes. */
194typedef enum {
195 MBEDTLS_MODE_NONE = 0, /**< None. */
196 MBEDTLS_MODE_ECB, /**< The ECB cipher mode. */
197 MBEDTLS_MODE_CBC, /**< The CBC cipher mode. */
198 MBEDTLS_MODE_CFB, /**< The CFB cipher mode. */
199 MBEDTLS_MODE_OFB, /**< The OFB cipher mode. */
200 MBEDTLS_MODE_CTR, /**< The CTR cipher mode. */
201 MBEDTLS_MODE_GCM, /**< The GCM cipher mode. */
202 MBEDTLS_MODE_STREAM, /**< The stream cipher mode. */
203 MBEDTLS_MODE_CCM, /**< The CCM cipher mode. */
204 MBEDTLS_MODE_XTS, /**< The XTS cipher mode. */
205 MBEDTLS_MODE_CHACHAPOLY, /**< The ChaCha-Poly cipher mode. */
206 MBEDTLS_MODE_KW, /**< The SP800-38F KW mode */
207 MBEDTLS_MODE_KWP, /**< The SP800-38F KWP mode */
208} mbedtls_cipher_mode_t;
209
210/** Supported cipher padding types. */
211typedef enum {
212 MBEDTLS_PADDING_PKCS7 = 0, /**< PKCS7 padding (default). */
213 MBEDTLS_PADDING_ONE_AND_ZEROS, /**< ISO/IEC 7816-4 padding. */
214 MBEDTLS_PADDING_ZEROS_AND_LEN, /**< ANSI X.923 padding. */
215 MBEDTLS_PADDING_ZEROS, /**< Zero padding (not reversible). */
216 MBEDTLS_PADDING_NONE, /**< Never pad (full blocks only). */
217} mbedtls_cipher_padding_t;
218
219/** Type of operation. */
220typedef enum {
221 MBEDTLS_OPERATION_NONE = -1,
222 MBEDTLS_DECRYPT = 0,
223 MBEDTLS_ENCRYPT,
224} mbedtls_operation_t;
225
226enum {
227 /** Undefined key length. */
228 MBEDTLS_KEY_LENGTH_NONE = 0,
229 /** Key length, in bits (including parity), for DES keys. \warning DES is considered weak. */
230 MBEDTLS_KEY_LENGTH_DES = 64,
231 /** Key length in bits, including parity, for DES in two-key EDE. \warning 3DES is considered weak. */
232 MBEDTLS_KEY_LENGTH_DES_EDE = 128,
233 /** Key length in bits, including parity, for DES in three-key EDE. \warning 3DES is considered weak. */
234 MBEDTLS_KEY_LENGTH_DES_EDE3 = 192,
235};
236
237/** Maximum length of any IV, in Bytes. */
238/* This should ideally be derived automatically from list of ciphers.
239 * This should be kept in sync with MBEDTLS_SSL_MAX_IV_LENGTH defined
240 * in ssl_internal.h. */
241#define MBEDTLS_MAX_IV_LENGTH 16
242
243/** Maximum block size of any cipher, in Bytes. */
244/* This should ideally be derived automatically from list of ciphers.
245 * This should be kept in sync with MBEDTLS_SSL_MAX_BLOCK_LENGTH defined
246 * in ssl_internal.h. */
247#define MBEDTLS_MAX_BLOCK_LENGTH 16
248
249/** Maximum key length, in Bytes. */
250/* This should ideally be derived automatically from list of ciphers.
251 * For now, only check whether XTS is enabled which uses 64 Byte keys,
252 * and use 32 Bytes as an upper bound for the maximum key length otherwise.
253 * This should be kept in sync with MBEDTLS_SSL_MAX_BLOCK_LENGTH defined
254 * in ssl_internal.h, which however deliberately ignores the case of XTS
255 * since the latter isn't used in SSL/TLS. */
256#if defined(MBEDTLS_CIPHER_MODE_XTS)
257#define MBEDTLS_MAX_KEY_LENGTH 64
258#else
259#define MBEDTLS_MAX_KEY_LENGTH 32
260#endif /* MBEDTLS_CIPHER_MODE_XTS */
261
262/**
263 * Base cipher information (opaque struct).
264 */
265typedef struct mbedtls_cipher_base_t mbedtls_cipher_base_t;
266
267/**
268 * CMAC context (opaque struct).
269 */
270typedef struct mbedtls_cmac_context_t mbedtls_cmac_context_t;
271
272/**
273 * Cipher information. Allows calling cipher functions
274 * in a generic way.
275 */
276typedef struct mbedtls_cipher_info_t {
277 /** Full cipher identifier. For example,
278 * MBEDTLS_CIPHER_AES_256_CBC.
279 */
280 mbedtls_cipher_type_t type;
281
282 /** The cipher mode. For example, MBEDTLS_MODE_CBC. */
283 mbedtls_cipher_mode_t mode;
284
285 /** The cipher key length, in bits. This is the
286 * default length for variable sized ciphers.
287 * Includes parity bits for ciphers like DES.
288 */
289 unsigned int key_bitlen;
290
291 /** Name of the cipher. */
292 const char *name;
293
294 /** IV or nonce size, in Bytes.
295 * For ciphers that accept variable IV sizes,
296 * this is the recommended size.
297 */
298 unsigned int iv_size;
299
300 /** Bitflag comprised of MBEDTLS_CIPHER_VARIABLE_IV_LEN and
301 * MBEDTLS_CIPHER_VARIABLE_KEY_LEN indicating whether the
302 * cipher supports variable IV or variable key sizes, respectively.
303 */
304 int flags;
305
306 /** The block size, in Bytes. */
307 unsigned int block_size;
308
309 /** Struct for base cipher information and functions. */
310 const mbedtls_cipher_base_t *base;
311
312} mbedtls_cipher_info_t;
313
314/**
315 * Generic cipher context.
316 */
317typedef struct mbedtls_cipher_context_t {
318 /** Information about the associated cipher. */
319 const mbedtls_cipher_info_t *cipher_info;
320
321 /** Key length to use. */
322 int key_bitlen;
323
324 /** Operation that the key of the context has been
325 * initialized for.
326 */
327 mbedtls_operation_t operation;
328
329#if defined(MBEDTLS_CIPHER_MODE_WITH_PADDING)
330 /** Padding functions to use, if relevant for
331 * the specific cipher mode.
332 */
333 void (*add_padding)(unsigned char *output, size_t olen, size_t data_len);
334 int (*get_padding)(unsigned char *input, size_t ilen, size_t *data_len);
335#endif
336
337 /** Buffer for input that has not been processed yet. */
338 unsigned char unprocessed_data[MBEDTLS_MAX_BLOCK_LENGTH];
339
340 /** Number of Bytes that have not been processed yet. */
341 size_t unprocessed_len;
342
343 /** Current IV or NONCE_COUNTER for CTR-mode, data unit (or sector) number
344 * for XTS-mode. */
345 unsigned char iv[MBEDTLS_MAX_IV_LENGTH];
346
347 /** IV size in Bytes, for ciphers with variable-length IVs. */
348 size_t iv_size;
349
350 /** The cipher-specific context. */
351 void *cipher_ctx;
352
353#if defined(MBEDTLS_CMAC_C)
354 /** CMAC-specific context. */
355 mbedtls_cmac_context_t *cmac_ctx;
356#endif
357
358#if defined(MBEDTLS_USE_PSA_CRYPTO)
359 /** Indicates whether the cipher operations should be performed
360 * by Mbed TLS' own crypto library or an external implementation
361 * of the PSA Crypto API.
362 * This is unset if the cipher context was established through
363 * mbedtls_cipher_setup(), and set if it was established through
364 * mbedtls_cipher_setup_psa().
365 */
366 unsigned char psa_enabled;
367#endif /* MBEDTLS_USE_PSA_CRYPTO */
368
369} mbedtls_cipher_context_t;
370
371/**
372 * \brief This function retrieves the list of ciphers supported
373 * by the generic cipher module.
374 *
375 * For any cipher identifier in the returned list, you can
376 * obtain the corresponding generic cipher information structure
377 * via mbedtls_cipher_info_from_type(), which can then be used
378 * to prepare a cipher context via mbedtls_cipher_setup().
379 *
380 *
381 * \return A statically-allocated array of cipher identifiers
382 * of type cipher_type_t. The last entry is zero.
383 */
384const int *mbedtls_cipher_list(void);
385
386/**
387 * \brief This function retrieves the cipher-information
388 * structure associated with the given cipher name.
389 *
390 * \param cipher_name Name of the cipher to search for. This must not be
391 * \c NULL.
392 *
393 * \return The cipher information structure associated with the
394 * given \p cipher_name.
395 * \return \c NULL if the associated cipher information is not found.
396 */
397const mbedtls_cipher_info_t *mbedtls_cipher_info_from_string(const char *cipher_name);
398
399/**
400 * \brief This function retrieves the cipher-information
401 * structure associated with the given cipher type.
402 *
403 * \param cipher_type Type of the cipher to search for.
404 *
405 * \return The cipher information structure associated with the
406 * given \p cipher_type.
407 * \return \c NULL if the associated cipher information is not found.
408 */
409const mbedtls_cipher_info_t *mbedtls_cipher_info_from_type(const mbedtls_cipher_type_t cipher_type);
410
411/**
412 * \brief This function retrieves the cipher-information
413 * structure associated with the given cipher ID,
414 * key size and mode.
415 *
416 * \param cipher_id The ID of the cipher to search for. For example,
417 * #MBEDTLS_CIPHER_ID_AES.
418 * \param key_bitlen The length of the key in bits.
419 * \param mode The cipher mode. For example, #MBEDTLS_MODE_CBC.
420 *
421 * \return The cipher information structure associated with the
422 * given \p cipher_id.
423 * \return \c NULL if the associated cipher information is not found.
424 */
425const mbedtls_cipher_info_t *mbedtls_cipher_info_from_values(const mbedtls_cipher_id_t cipher_id,
426 int key_bitlen,
427 const mbedtls_cipher_mode_t mode);
428
429/**
430 * \brief This function initializes a \p ctx as NONE.
431 *
432 * \param ctx The context to be initialized. This must not be \c NULL.
433 */
434void mbedtls_cipher_init(mbedtls_cipher_context_t *ctx);
435
436/**
437 * \brief This function frees and clears the cipher-specific
438 * context of \p ctx. Freeing \p ctx itself remains the
439 * responsibility of the caller.
440 *
441 * \param ctx The context to be freed. If this is \c NULL, the
442 * function has no effect, otherwise this must point to an
443 * initialized context.
444 */
445void mbedtls_cipher_free(mbedtls_cipher_context_t *ctx);
446
447
448/**
449 * \brief This function initializes a cipher context for
450 * use with the given cipher primitive.
451 *
452 * \param ctx The context to initialize. This must be initialized.
453 * \param cipher_info The cipher to use.
454 *
455 * \return \c 0 on success.
456 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
457 * parameter-verification failure.
458 * \return #MBEDTLS_ERR_CIPHER_ALLOC_FAILED if allocation of the
459 * cipher-specific context fails.
460 *
461 * \internal Currently, the function also clears the structure.
462 * In future versions, the caller will be required to call
463 * mbedtls_cipher_init() on the structure first.
464 */
465int mbedtls_cipher_setup(mbedtls_cipher_context_t *ctx,
466 const mbedtls_cipher_info_t *cipher_info);
467
468#if defined(MBEDTLS_USE_PSA_CRYPTO)
469/**
470 * \brief This function initializes a cipher context for
471 * PSA-based use with the given cipher primitive.
472 *
473 * \note See #MBEDTLS_USE_PSA_CRYPTO for information on PSA.
474 *
475 * \param ctx The context to initialize. May not be \c NULL.
476 * \param cipher_info The cipher to use.
477 * \param taglen For AEAD ciphers, the length in bytes of the
478 * authentication tag to use. Subsequent uses of
479 * mbedtls_cipher_auth_encrypt() or
480 * mbedtls_cipher_auth_decrypt() must provide
481 * the same tag length.
482 * For non-AEAD ciphers, the value must be \c 0.
483 *
484 * \return \c 0 on success.
485 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
486 * parameter-verification failure.
487 * \return #MBEDTLS_ERR_CIPHER_ALLOC_FAILED if allocation of the
488 * cipher-specific context fails.
489 */
490int mbedtls_cipher_setup_psa(mbedtls_cipher_context_t *ctx,
491 const mbedtls_cipher_info_t *cipher_info,
492 size_t taglen);
493#endif /* MBEDTLS_USE_PSA_CRYPTO */
494
495/**
496 * \brief This function returns the block size of the given cipher.
497 *
498 * \param ctx The context of the cipher. This must be initialized.
499 *
500 * \return The block size of the underlying cipher.
501 * \return \c 0 if \p ctx has not been initialized.
502 */
503static inline unsigned int mbedtls_cipher_get_block_size(
504 const mbedtls_cipher_context_t *ctx)
505{
506 MBEDTLS_INTERNAL_VALIDATE_RET(ctx != NULL, 0);
507 if (ctx->cipher_info == NULL) {
508 return 0;
509 }
510
511 return ctx->cipher_info->block_size;
512}
513
514/**
515 * \brief This function returns the mode of operation for
516 * the cipher. For example, MBEDTLS_MODE_CBC.
517 *
518 * \param ctx The context of the cipher. This must be initialized.
519 *
520 * \return The mode of operation.
521 * \return #MBEDTLS_MODE_NONE if \p ctx has not been initialized.
522 */
523static inline mbedtls_cipher_mode_t mbedtls_cipher_get_cipher_mode(
524 const mbedtls_cipher_context_t *ctx)
525{
526 MBEDTLS_INTERNAL_VALIDATE_RET(ctx != NULL, MBEDTLS_MODE_NONE);
527 if (ctx->cipher_info == NULL) {
528 return MBEDTLS_MODE_NONE;
529 }
530
531 return ctx->cipher_info->mode;
532}
533
534/**
535 * \brief This function returns the size of the IV or nonce
536 * of the cipher, in Bytes.
537 *
538 * \param ctx The context of the cipher. This must be initialized.
539 *
540 * \return The recommended IV size if no IV has been set.
541 * \return \c 0 for ciphers not using an IV or a nonce.
542 * \return The actual size if an IV has been set.
543 */
544static inline int mbedtls_cipher_get_iv_size(
545 const mbedtls_cipher_context_t *ctx)
546{
547 MBEDTLS_INTERNAL_VALIDATE_RET(ctx != NULL, 0);
548 if (ctx->cipher_info == NULL) {
549 return 0;
550 }
551
552 if (ctx->iv_size != 0) {
553 return (int) ctx->iv_size;
554 }
555
556 return (int) ctx->cipher_info->iv_size;
557}
558
559/**
560 * \brief This function returns the type of the given cipher.
561 *
562 * \param ctx The context of the cipher. This must be initialized.
563 *
564 * \return The type of the cipher.
565 * \return #MBEDTLS_CIPHER_NONE if \p ctx has not been initialized.
566 */
567static inline mbedtls_cipher_type_t mbedtls_cipher_get_type(
568 const mbedtls_cipher_context_t *ctx)
569{
570 MBEDTLS_INTERNAL_VALIDATE_RET(
571 ctx != NULL, MBEDTLS_CIPHER_NONE);
572 if (ctx->cipher_info == NULL) {
573 return MBEDTLS_CIPHER_NONE;
574 }
575
576 return ctx->cipher_info->type;
577}
578
579/**
580 * \brief This function returns the name of the given cipher
581 * as a string.
582 *
583 * \param ctx The context of the cipher. This must be initialized.
584 *
585 * \return The name of the cipher.
586 * \return NULL if \p ctx has not been not initialized.
587 */
588static inline const char *mbedtls_cipher_get_name(
589 const mbedtls_cipher_context_t *ctx)
590{
591 MBEDTLS_INTERNAL_VALIDATE_RET(ctx != NULL, 0);
592 if (ctx->cipher_info == NULL) {
593 return 0;
594 }
595
596 return ctx->cipher_info->name;
597}
598
599/**
600 * \brief This function returns the key length of the cipher.
601 *
602 * \param ctx The context of the cipher. This must be initialized.
603 *
604 * \return The key length of the cipher in bits.
605 * \return #MBEDTLS_KEY_LENGTH_NONE if \p ctx has not been
606 * initialized.
607 */
608static inline int mbedtls_cipher_get_key_bitlen(
609 const mbedtls_cipher_context_t *ctx)
610{
611 MBEDTLS_INTERNAL_VALIDATE_RET(
612 ctx != NULL, MBEDTLS_KEY_LENGTH_NONE);
613 if (ctx->cipher_info == NULL) {
614 return MBEDTLS_KEY_LENGTH_NONE;
615 }
616
617 return (int) ctx->cipher_info->key_bitlen;
618}
619
620/**
621 * \brief This function returns the operation of the given cipher.
622 *
623 * \param ctx The context of the cipher. This must be initialized.
624 *
625 * \return The type of operation: #MBEDTLS_ENCRYPT or #MBEDTLS_DECRYPT.
626 * \return #MBEDTLS_OPERATION_NONE if \p ctx has not been initialized.
627 */
628static inline mbedtls_operation_t mbedtls_cipher_get_operation(
629 const mbedtls_cipher_context_t *ctx)
630{
631 MBEDTLS_INTERNAL_VALIDATE_RET(
632 ctx != NULL, MBEDTLS_OPERATION_NONE);
633 if (ctx->cipher_info == NULL) {
634 return MBEDTLS_OPERATION_NONE;
635 }
636
637 return ctx->operation;
638}
639
640/**
641 * \brief This function sets the key to use with the given context.
642 *
643 * \param ctx The generic cipher context. This must be initialized and
644 * bound to a cipher information structure.
645 * \param key The key to use. This must be a readable buffer of at
646 * least \p key_bitlen Bits.
647 * \param key_bitlen The key length to use, in Bits.
648 * \param operation The operation that the key will be used for:
649 * #MBEDTLS_ENCRYPT or #MBEDTLS_DECRYPT.
650 *
651 * \return \c 0 on success.
652 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
653 * parameter-verification failure.
654 * \return A cipher-specific error code on failure.
655 */
656int mbedtls_cipher_setkey(mbedtls_cipher_context_t *ctx,
657 const unsigned char *key,
658 int key_bitlen,
659 const mbedtls_operation_t operation);
660
661#if defined(MBEDTLS_CIPHER_MODE_WITH_PADDING)
662/**
663 * \brief This function sets the padding mode, for cipher modes
664 * that use padding.
665 *
666 * The default passing mode is PKCS7 padding.
667 *
668 * \param ctx The generic cipher context. This must be initialized and
669 * bound to a cipher information structure.
670 * \param mode The padding mode.
671 *
672 * \return \c 0 on success.
673 * \return #MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE
674 * if the selected padding mode is not supported.
675 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA if the cipher mode
676 * does not support padding.
677 */
678int mbedtls_cipher_set_padding_mode(mbedtls_cipher_context_t *ctx,
679 mbedtls_cipher_padding_t mode);
680#endif /* MBEDTLS_CIPHER_MODE_WITH_PADDING */
681
682/**
683 * \brief This function sets the initialization vector (IV)
684 * or nonce.
685 *
686 * \note Some ciphers do not use IVs nor nonce. For these
687 * ciphers, this function has no effect.
688 *
689 * \param ctx The generic cipher context. This must be initialized and
690 * bound to a cipher information structure.
691 * \param iv The IV to use, or NONCE_COUNTER for CTR-mode ciphers. This
692 * must be a readable buffer of at least \p iv_len Bytes.
693 * \param iv_len The IV length for ciphers with variable-size IV.
694 * This parameter is discarded by ciphers with fixed-size IV.
695 *
696 * \return \c 0 on success.
697 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
698 * parameter-verification failure.
699 */
700int mbedtls_cipher_set_iv(mbedtls_cipher_context_t *ctx,
701 const unsigned char *iv,
702 size_t iv_len);
703
704/**
705 * \brief This function resets the cipher state.
706 *
707 * \param ctx The generic cipher context. This must be initialized.
708 *
709 * \return \c 0 on success.
710 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
711 * parameter-verification failure.
712 */
713int mbedtls_cipher_reset(mbedtls_cipher_context_t *ctx);
714
715#if defined(MBEDTLS_GCM_C) || defined(MBEDTLS_CHACHAPOLY_C)
716/**
717 * \brief This function adds additional data for AEAD ciphers.
718 * Currently supported with GCM and ChaCha20+Poly1305.
719 * This must be called exactly once, after
720 * mbedtls_cipher_reset().
721 *
722 * \param ctx The generic cipher context. This must be initialized.
723 * \param ad The additional data to use. This must be a readable
724 * buffer of at least \p ad_len Bytes.
725 * \param ad_len The length of \p ad in Bytes.
726 *
727 * \return \c 0 on success.
728 * \return A specific error code on failure.
729 */
730int mbedtls_cipher_update_ad(mbedtls_cipher_context_t *ctx,
731 const unsigned char *ad, size_t ad_len);
732#endif /* MBEDTLS_GCM_C || MBEDTLS_CHACHAPOLY_C */
733
734/**
735 * \brief The generic cipher update function. It encrypts or
736 * decrypts using the given cipher context. Writes as
737 * many block-sized blocks of data as possible to output.
738 * Any data that cannot be written immediately is either
739 * added to the next block, or flushed when
740 * mbedtls_cipher_finish() is called.
741 * Exception: For MBEDTLS_MODE_ECB, expects a single block
742 * in size. For example, 16 Bytes for AES.
743 *
744 * \note If the underlying cipher is used in GCM mode, all calls
745 * to this function, except for the last one before
746 * mbedtls_cipher_finish(), must have \p ilen as a
747 * multiple of the block size of the cipher.
748 *
749 * \param ctx The generic cipher context. This must be initialized and
750 * bound to a key.
751 * \param input The buffer holding the input data. This must be a
752 * readable buffer of at least \p ilen Bytes.
753 * \param ilen The length of the input data.
754 * \param output The buffer for the output data. This must be able to
755 * hold at least `ilen + block_size`. This must not be the
756 * same buffer as \p input.
757 * \param olen The length of the output data, to be updated with the
758 * actual number of Bytes written. This must not be
759 * \c NULL.
760 *
761 * \return \c 0 on success.
762 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
763 * parameter-verification failure.
764 * \return #MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE on an
765 * unsupported mode for a cipher.
766 * \return A cipher-specific error code on failure.
767 */
768int mbedtls_cipher_update(mbedtls_cipher_context_t *ctx,
769 const unsigned char *input,
770 size_t ilen, unsigned char *output,
771 size_t *olen);
772
773/**
774 * \brief The generic cipher finalization function. If data still
775 * needs to be flushed from an incomplete block, the data
776 * contained in it is padded to the size of
777 * the last block, and written to the \p output buffer.
778 *
779 * \param ctx The generic cipher context. This must be initialized and
780 * bound to a key.
781 * \param output The buffer to write data to. This needs to be a writable
782 * buffer of at least block_size Bytes.
783 * \param olen The length of the data written to the \p output buffer.
784 * This may not be \c NULL.
785 *
786 * \return \c 0 on success.
787 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
788 * parameter-verification failure.
789 * \return #MBEDTLS_ERR_CIPHER_FULL_BLOCK_EXPECTED on decryption
790 * expecting a full block but not receiving one.
791 * \return #MBEDTLS_ERR_CIPHER_INVALID_PADDING on invalid padding
792 * while decrypting.
793 * \return A cipher-specific error code on failure.
794 */
795int mbedtls_cipher_finish(mbedtls_cipher_context_t *ctx,
796 unsigned char *output, size_t *olen);
797
798#if defined(MBEDTLS_GCM_C) || defined(MBEDTLS_CHACHAPOLY_C)
799/**
800 * \brief This function writes a tag for AEAD ciphers.
801 * Currently supported with GCM and ChaCha20+Poly1305.
802 * This must be called after mbedtls_cipher_finish().
803 *
804 * \param ctx The generic cipher context. This must be initialized,
805 * bound to a key, and have just completed a cipher
806 * operation through mbedtls_cipher_finish() the tag for
807 * which should be written.
808 * \param tag The buffer to write the tag to. This must be a writable
809 * buffer of at least \p tag_len Bytes.
810 * \param tag_len The length of the tag to write.
811 *
812 * \return \c 0 on success.
813 * \return A specific error code on failure.
814 */
815int mbedtls_cipher_write_tag(mbedtls_cipher_context_t *ctx,
816 unsigned char *tag, size_t tag_len);
817
818/**
819 * \brief This function checks the tag for AEAD ciphers.
820 * Currently supported with GCM and ChaCha20+Poly1305.
821 * This must be called after mbedtls_cipher_finish().
822 *
823 * \param ctx The generic cipher context. This must be initialized.
824 * \param tag The buffer holding the tag. This must be a readable
825 * buffer of at least \p tag_len Bytes.
826 * \param tag_len The length of the tag to check.
827 *
828 * \return \c 0 on success.
829 * \return A specific error code on failure.
830 */
831int mbedtls_cipher_check_tag(mbedtls_cipher_context_t *ctx,
832 const unsigned char *tag, size_t tag_len);
833#endif /* MBEDTLS_GCM_C || MBEDTLS_CHACHAPOLY_C */
834
835/**
836 * \brief The generic all-in-one encryption/decryption function,
837 * for all ciphers except AEAD constructs.
838 *
839 * \param ctx The generic cipher context. This must be initialized.
840 * \param iv The IV to use, or NONCE_COUNTER for CTR-mode ciphers.
841 * This must be a readable buffer of at least \p iv_len
842 * Bytes.
843 * \param iv_len The IV length for ciphers with variable-size IV.
844 * This parameter is discarded by ciphers with fixed-size
845 * IV.
846 * \param input The buffer holding the input data. This must be a
847 * readable buffer of at least \p ilen Bytes.
848 * \param ilen The length of the input data in Bytes.
849 * \param output The buffer for the output data. This must be able to
850 * hold at least `ilen + block_size`. This must not be the
851 * same buffer as \p input.
852 * \param olen The length of the output data, to be updated with the
853 * actual number of Bytes written. This must not be
854 * \c NULL.
855 *
856 * \note Some ciphers do not use IVs nor nonce. For these
857 * ciphers, use \p iv = NULL and \p iv_len = 0.
858 *
859 * \return \c 0 on success.
860 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
861 * parameter-verification failure.
862 * \return #MBEDTLS_ERR_CIPHER_FULL_BLOCK_EXPECTED on decryption
863 * expecting a full block but not receiving one.
864 * \return #MBEDTLS_ERR_CIPHER_INVALID_PADDING on invalid padding
865 * while decrypting.
866 * \return A cipher-specific error code on failure.
867 */
868int mbedtls_cipher_crypt(mbedtls_cipher_context_t *ctx,
869 const unsigned char *iv, size_t iv_len,
870 const unsigned char *input, size_t ilen,
871 unsigned char *output, size_t *olen);
872
873#if defined(MBEDTLS_CIPHER_MODE_AEAD)
874#if !defined(MBEDTLS_DEPRECATED_REMOVED)
875#if defined(MBEDTLS_DEPRECATED_WARNING)
876#define MBEDTLS_DEPRECATED __attribute__((deprecated))
877#else
878#define MBEDTLS_DEPRECATED
879#endif /* MBEDTLS_DEPRECATED_WARNING */
880/**
881 * \brief The generic authenticated encryption (AEAD) function.
882 *
883 * \deprecated Superseded by mbedtls_cipher_auth_encrypt_ext().
884 *
885 * \note This function only supports AEAD algorithms, not key
886 * wrapping algorithms such as NIST_KW; for this, see
887 * mbedtls_cipher_auth_encrypt_ext().
888 *
889 * \param ctx The generic cipher context. This must be initialized and
890 * bound to a key associated with an AEAD algorithm.
891 * \param iv The nonce to use. This must be a readable buffer of
892 * at least \p iv_len Bytes and must not be \c NULL.
893 * \param iv_len The length of the nonce. This must satisfy the
894 * constraints imposed by the AEAD cipher used.
895 * \param ad The additional data to authenticate. This must be a
896 * readable buffer of at least \p ad_len Bytes, and may
897 * be \c NULL is \p ad_len is \c 0.
898 * \param ad_len The length of \p ad.
899 * \param input The buffer holding the input data. This must be a
900 * readable buffer of at least \p ilen Bytes, and may be
901 * \c NULL if \p ilen is \c 0.
902 * \param ilen The length of the input data.
903 * \param output The buffer for the output data. This must be a
904 * writable buffer of at least \p ilen Bytes, and must
905 * not be \c NULL.
906 * \param olen This will be filled with the actual number of Bytes
907 * written to the \p output buffer. This must point to a
908 * writable object of type \c size_t.
909 * \param tag The buffer for the authentication tag. This must be a
910 * writable buffer of at least \p tag_len Bytes. See note
911 * below regarding restrictions with PSA-based contexts.
912 * \param tag_len The desired length of the authentication tag. This
913 * must match the constraints imposed by the AEAD cipher
914 * used, and in particular must not be \c 0.
915 *
916 * \note If the context is based on PSA (that is, it was set up
917 * with mbedtls_cipher_setup_psa()), then it is required
918 * that \c tag == output + ilen. That is, the tag must be
919 * appended to the ciphertext as recommended by RFC 5116.
920 *
921 * \return \c 0 on success.
922 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
923 * parameter-verification failure.
924 * \return A cipher-specific error code on failure.
925 */
926int MBEDTLS_DEPRECATED mbedtls_cipher_auth_encrypt(
927 mbedtls_cipher_context_t *ctx,
928 const unsigned char *iv, size_t iv_len,
929 const unsigned char *ad, size_t ad_len,
930 const unsigned char *input, size_t ilen,
931 unsigned char *output, size_t *olen,
932 unsigned char *tag, size_t tag_len);
933
934/**
935 * \brief The generic authenticated decryption (AEAD) function.
936 *
937 * \deprecated Superseded by mbedtls_cipher_auth_decrypt_ext().
938 *
939 * \note This function only supports AEAD algorithms, not key
940 * wrapping algorithms such as NIST_KW; for this, see
941 * mbedtls_cipher_auth_decrypt_ext().
942 *
943 * \note If the data is not authentic, then the output buffer
944 * is zeroed out to prevent the unauthentic plaintext being
945 * used, making this interface safer.
946 *
947 * \param ctx The generic cipher context. This must be initialized and
948 * bound to a key associated with an AEAD algorithm.
949 * \param iv The nonce to use. This must be a readable buffer of
950 * at least \p iv_len Bytes and must not be \c NULL.
951 * \param iv_len The length of the nonce. This must satisfy the
952 * constraints imposed by the AEAD cipher used.
953 * \param ad The additional data to authenticate. This must be a
954 * readable buffer of at least \p ad_len Bytes, and may
955 * be \c NULL is \p ad_len is \c 0.
956 * \param ad_len The length of \p ad.
957 * \param input The buffer holding the input data. This must be a
958 * readable buffer of at least \p ilen Bytes, and may be
959 * \c NULL if \p ilen is \c 0.
960 * \param ilen The length of the input data.
961 * \param output The buffer for the output data. This must be a
962 * writable buffer of at least \p ilen Bytes, and must
963 * not be \c NULL.
964 * \param olen This will be filled with the actual number of Bytes
965 * written to the \p output buffer. This must point to a
966 * writable object of type \c size_t.
967 * \param tag The buffer for the authentication tag. This must be a
968 * readable buffer of at least \p tag_len Bytes. See note
969 * below regarding restrictions with PSA-based contexts.
970 * \param tag_len The length of the authentication tag. This must match
971 * the constraints imposed by the AEAD cipher used, and in
972 * particular must not be \c 0.
973 *
974 * \note If the context is based on PSA (that is, it was set up
975 * with mbedtls_cipher_setup_psa()), then it is required
976 * that \c tag == input + len. That is, the tag must be
977 * appended to the ciphertext as recommended by RFC 5116.
978 *
979 * \return \c 0 on success.
980 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
981 * parameter-verification failure.
982 * \return #MBEDTLS_ERR_CIPHER_AUTH_FAILED if data is not authentic.
983 * \return A cipher-specific error code on failure.
984 */
985int MBEDTLS_DEPRECATED mbedtls_cipher_auth_decrypt(
986 mbedtls_cipher_context_t *ctx,
987 const unsigned char *iv, size_t iv_len,
988 const unsigned char *ad, size_t ad_len,
989 const unsigned char *input, size_t ilen,
990 unsigned char *output, size_t *olen,
991 const unsigned char *tag, size_t tag_len);
992#undef MBEDTLS_DEPRECATED
993#endif /* MBEDTLS_DEPRECATED_REMOVED */
994#endif /* MBEDTLS_CIPHER_MODE_AEAD */
995
996#if defined(MBEDTLS_CIPHER_MODE_AEAD) || defined(MBEDTLS_NIST_KW_C)
997/**
998 * \brief The authenticated encryption (AEAD/NIST_KW) function.
999 *
1000 * \note For AEAD modes, the tag will be appended to the
1001 * ciphertext, as recommended by RFC 5116.
1002 * (NIST_KW doesn't have a separate tag.)
1003 *
1004 * \param ctx The generic cipher context. This must be initialized and
1005 * bound to a key, with an AEAD algorithm or NIST_KW.
1006 * \param iv The nonce to use. This must be a readable buffer of
1007 * at least \p iv_len Bytes and may be \c NULL if \p
1008 * iv_len is \c 0.
1009 * \param iv_len The length of the nonce. For AEAD ciphers, this must
1010 * satisfy the constraints imposed by the cipher used.
1011 * For NIST_KW, this must be \c 0.
1012 * \param ad The additional data to authenticate. This must be a
1013 * readable buffer of at least \p ad_len Bytes, and may
1014 * be \c NULL is \p ad_len is \c 0.
1015 * \param ad_len The length of \p ad. For NIST_KW, this must be \c 0.
1016 * \param input The buffer holding the input data. This must be a
1017 * readable buffer of at least \p ilen Bytes, and may be
1018 * \c NULL if \p ilen is \c 0.
1019 * \param ilen The length of the input data.
1020 * \param output The buffer for the output data. This must be a
1021 * writable buffer of at least \p output_len Bytes, and
1022 * must not be \c NULL.
1023 * \param output_len The length of the \p output buffer in Bytes. For AEAD
1024 * ciphers, this must be at least \p ilen + \p tag_len.
1025 * For NIST_KW, this must be at least \p ilen + 8
1026 * (rounded up to a multiple of 8 if KWP is used);
1027 * \p ilen + 15 is always a safe value.
1028 * \param olen This will be filled with the actual number of Bytes
1029 * written to the \p output buffer. This must point to a
1030 * writable object of type \c size_t.
1031 * \param tag_len The desired length of the authentication tag. For AEAD
1032 * ciphers, this must match the constraints imposed by
1033 * the cipher used, and in particular must not be \c 0.
1034 * For NIST_KW, this must be \c 0.
1035 *
1036 * \return \c 0 on success.
1037 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
1038 * parameter-verification failure.
1039 * \return A cipher-specific error code on failure.
1040 */
1041int mbedtls_cipher_auth_encrypt_ext(mbedtls_cipher_context_t *ctx,
1042 const unsigned char *iv, size_t iv_len,
1043 const unsigned char *ad, size_t ad_len,
1044 const unsigned char *input, size_t ilen,
1045 unsigned char *output, size_t output_len,
1046 size_t *olen, size_t tag_len);
1047
1048/**
1049 * \brief The authenticated encryption (AEAD/NIST_KW) function.
1050 *
1051 * \note If the data is not authentic, then the output buffer
1052 * is zeroed out to prevent the unauthentic plaintext being
1053 * used, making this interface safer.
1054 *
1055 * \note For AEAD modes, the tag must be appended to the
1056 * ciphertext, as recommended by RFC 5116.
1057 * (NIST_KW doesn't have a separate tag.)
1058 *
1059 * \param ctx The generic cipher context. This must be initialized and
1060 * bound to a key, with an AEAD algorithm or NIST_KW.
1061 * \param iv The nonce to use. This must be a readable buffer of
1062 * at least \p iv_len Bytes and may be \c NULL if \p
1063 * iv_len is \c 0.
1064 * \param iv_len The length of the nonce. For AEAD ciphers, this must
1065 * satisfy the constraints imposed by the cipher used.
1066 * For NIST_KW, this must be \c 0.
1067 * \param ad The additional data to authenticate. This must be a
1068 * readable buffer of at least \p ad_len Bytes, and may
1069 * be \c NULL is \p ad_len is \c 0.
1070 * \param ad_len The length of \p ad. For NIST_KW, this must be \c 0.
1071 * \param input The buffer holding the input data. This must be a
1072 * readable buffer of at least \p ilen Bytes, and may be
1073 * \c NULL if \p ilen is \c 0.
1074 * \param ilen The length of the input data. For AEAD ciphers this
1075 * must be at least \p tag_len. For NIST_KW this must be
1076 * at least \c 8.
1077 * \param output The buffer for the output data. This must be a
1078 * writable buffer of at least \p output_len Bytes, and
1079 * may be \c NULL if \p output_len is \c 0.
1080 * \param output_len The length of the \p output buffer in Bytes. For AEAD
1081 * ciphers, this must be at least \p ilen - \p tag_len.
1082 * For NIST_KW, this must be at least \p ilen - 8.
1083 * \param olen This will be filled with the actual number of Bytes
1084 * written to the \p output buffer. This must point to a
1085 * writable object of type \c size_t.
1086 * \param tag_len The actual length of the authentication tag. For AEAD
1087 * ciphers, this must match the constraints imposed by
1088 * the cipher used, and in particular must not be \c 0.
1089 * For NIST_KW, this must be \c 0.
1090 *
1091 * \return \c 0 on success.
1092 * \return #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
1093 * parameter-verification failure.
1094 * \return #MBEDTLS_ERR_CIPHER_AUTH_FAILED if data is not authentic.
1095 * \return A cipher-specific error code on failure.
1096 */
1097int mbedtls_cipher_auth_decrypt_ext(mbedtls_cipher_context_t *ctx,
1098 const unsigned char *iv, size_t iv_len,
1099 const unsigned char *ad, size_t ad_len,
1100 const unsigned char *input, size_t ilen,
1101 unsigned char *output, size_t output_len,
1102 size_t *olen, size_t tag_len);
1103#endif /* MBEDTLS_CIPHER_MODE_AEAD || MBEDTLS_NIST_KW_C */
1104#ifdef __cplusplus
1105}
1106#endif
1107
1108#endif /* MBEDTLS_CIPHER_H */
1109