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 #define MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE  -0x6080  /**< The selected feature is not available. */
58 #define MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA       -0x6100  /**< Bad input parameters. */
59 #define MBEDTLS_ERR_CIPHER_ALLOC_FAILED         -0x6180  /**< Failed to allocate memory. */
60 #define MBEDTLS_ERR_CIPHER_INVALID_PADDING      -0x6200  /**< Input data contains invalid padding and is rejected. */
61 #define MBEDTLS_ERR_CIPHER_FULL_BLOCK_EXPECTED  -0x6280  /**< Decryption of block requires a full block. */
62 #define MBEDTLS_ERR_CIPHER_AUTH_FAILED          -0x6300  /**< Authentication failed (for AEAD modes). */
63 #define MBEDTLS_ERR_CIPHER_INVALID_CONTEXT      -0x6380  /**< The context is invalid. For example, because it was freed. */
64 
65 /* MBEDTLS_ERR_CIPHER_HW_ACCEL_FAILED is deprecated and should not be used. */
66 #define MBEDTLS_ERR_CIPHER_HW_ACCEL_FAILED      -0x6400  /**< Cipher hardware accelerator failed. */
67 
68 #define MBEDTLS_CIPHER_VARIABLE_IV_LEN     0x01    /**< Cipher accepts IVs of variable length. */
69 #define MBEDTLS_CIPHER_VARIABLE_KEY_LEN    0x02    /**< Cipher accepts keys of variable length. */
70 
71 #ifdef __cplusplus
72 extern "C" {
73 #endif
74 
75 /**
76  * \brief     Supported cipher types.
77  *
78  * \warning   RC4 and DES are considered weak ciphers and their use
79  *            constitutes a security risk. Arm recommends considering stronger
80  *            ciphers instead.
81  */
82 typedef enum {
83     MBEDTLS_CIPHER_ID_NONE = 0,  /**< Placeholder to mark the end of cipher ID lists. */
84     MBEDTLS_CIPHER_ID_NULL,      /**< The identity cipher, treated as a stream cipher. */
85     MBEDTLS_CIPHER_ID_AES,       /**< The AES cipher. */
86     MBEDTLS_CIPHER_ID_DES,       /**< The DES cipher. */
87     MBEDTLS_CIPHER_ID_3DES,      /**< The Triple DES cipher. */
88     MBEDTLS_CIPHER_ID_CAMELLIA,  /**< The Camellia cipher. */
89     MBEDTLS_CIPHER_ID_BLOWFISH,  /**< The Blowfish cipher. */
90     MBEDTLS_CIPHER_ID_ARC4,      /**< The RC4 cipher. */
91     MBEDTLS_CIPHER_ID_ARIA,      /**< The Aria cipher. */
92     MBEDTLS_CIPHER_ID_CHACHA20,  /**< The ChaCha20 cipher. */
93 } mbedtls_cipher_id_t;
94 
95 /**
96  * \brief     Supported {cipher type, cipher mode} pairs.
97  *
98  * \warning   RC4 and DES are considered weak ciphers and their use
99  *            constitutes a security risk. Arm recommends considering stronger
100  *            ciphers instead.
101  */
102 typedef enum {
103     MBEDTLS_CIPHER_NONE = 0,             /**< Placeholder to mark the end of cipher-pair lists. */
104     MBEDTLS_CIPHER_NULL,                 /**< The identity stream cipher. */
105     MBEDTLS_CIPHER_AES_128_ECB,          /**< AES cipher with 128-bit ECB mode. */
106     MBEDTLS_CIPHER_AES_192_ECB,          /**< AES cipher with 192-bit ECB mode. */
107     MBEDTLS_CIPHER_AES_256_ECB,          /**< AES cipher with 256-bit ECB mode. */
108     MBEDTLS_CIPHER_AES_128_CBC,          /**< AES cipher with 128-bit CBC mode. */
109     MBEDTLS_CIPHER_AES_192_CBC,          /**< AES cipher with 192-bit CBC mode. */
110     MBEDTLS_CIPHER_AES_256_CBC,          /**< AES cipher with 256-bit CBC mode. */
111     MBEDTLS_CIPHER_AES_128_CFB128,       /**< AES cipher with 128-bit CFB128 mode. */
112     MBEDTLS_CIPHER_AES_192_CFB128,       /**< AES cipher with 192-bit CFB128 mode. */
113     MBEDTLS_CIPHER_AES_256_CFB128,       /**< AES cipher with 256-bit CFB128 mode. */
114     MBEDTLS_CIPHER_AES_128_CTR,          /**< AES cipher with 128-bit CTR mode. */
115     MBEDTLS_CIPHER_AES_192_CTR,          /**< AES cipher with 192-bit CTR mode. */
116     MBEDTLS_CIPHER_AES_256_CTR,          /**< AES cipher with 256-bit CTR mode. */
117     MBEDTLS_CIPHER_AES_128_GCM,          /**< AES cipher with 128-bit GCM mode. */
118     MBEDTLS_CIPHER_AES_192_GCM,          /**< AES cipher with 192-bit GCM mode. */
119     MBEDTLS_CIPHER_AES_256_GCM,          /**< AES cipher with 256-bit GCM mode. */
120     MBEDTLS_CIPHER_CAMELLIA_128_ECB,     /**< Camellia cipher with 128-bit ECB mode. */
121     MBEDTLS_CIPHER_CAMELLIA_192_ECB,     /**< Camellia cipher with 192-bit ECB mode. */
122     MBEDTLS_CIPHER_CAMELLIA_256_ECB,     /**< Camellia cipher with 256-bit ECB mode. */
123     MBEDTLS_CIPHER_CAMELLIA_128_CBC,     /**< Camellia cipher with 128-bit CBC mode. */
124     MBEDTLS_CIPHER_CAMELLIA_192_CBC,     /**< Camellia cipher with 192-bit CBC mode. */
125     MBEDTLS_CIPHER_CAMELLIA_256_CBC,     /**< Camellia cipher with 256-bit CBC mode. */
126     MBEDTLS_CIPHER_CAMELLIA_128_CFB128,  /**< Camellia cipher with 128-bit CFB128 mode. */
127     MBEDTLS_CIPHER_CAMELLIA_192_CFB128,  /**< Camellia cipher with 192-bit CFB128 mode. */
128     MBEDTLS_CIPHER_CAMELLIA_256_CFB128,  /**< Camellia cipher with 256-bit CFB128 mode. */
129     MBEDTLS_CIPHER_CAMELLIA_128_CTR,     /**< Camellia cipher with 128-bit CTR mode. */
130     MBEDTLS_CIPHER_CAMELLIA_192_CTR,     /**< Camellia cipher with 192-bit CTR mode. */
131     MBEDTLS_CIPHER_CAMELLIA_256_CTR,     /**< Camellia cipher with 256-bit CTR mode. */
132     MBEDTLS_CIPHER_CAMELLIA_128_GCM,     /**< Camellia cipher with 128-bit GCM mode. */
133     MBEDTLS_CIPHER_CAMELLIA_192_GCM,     /**< Camellia cipher with 192-bit GCM mode. */
134     MBEDTLS_CIPHER_CAMELLIA_256_GCM,     /**< Camellia cipher with 256-bit GCM mode. */
135     MBEDTLS_CIPHER_DES_ECB,              /**< DES cipher with ECB mode. */
136     MBEDTLS_CIPHER_DES_CBC,              /**< DES cipher with CBC mode. */
137     MBEDTLS_CIPHER_DES_EDE_ECB,          /**< DES cipher with EDE ECB mode. */
138     MBEDTLS_CIPHER_DES_EDE_CBC,          /**< DES cipher with EDE CBC mode. */
139     MBEDTLS_CIPHER_DES_EDE3_ECB,         /**< DES cipher with EDE3 ECB mode. */
140     MBEDTLS_CIPHER_DES_EDE3_CBC,         /**< DES cipher with EDE3 CBC mode. */
141     MBEDTLS_CIPHER_BLOWFISH_ECB,         /**< Blowfish cipher with ECB mode. */
142     MBEDTLS_CIPHER_BLOWFISH_CBC,         /**< Blowfish cipher with CBC mode. */
143     MBEDTLS_CIPHER_BLOWFISH_CFB64,       /**< Blowfish cipher with CFB64 mode. */
144     MBEDTLS_CIPHER_BLOWFISH_CTR,         /**< Blowfish cipher with CTR mode. */
145     MBEDTLS_CIPHER_ARC4_128,             /**< RC4 cipher with 128-bit mode. */
146     MBEDTLS_CIPHER_AES_128_CCM,          /**< AES cipher with 128-bit CCM mode. */
147     MBEDTLS_CIPHER_AES_192_CCM,          /**< AES cipher with 192-bit CCM mode. */
148     MBEDTLS_CIPHER_AES_256_CCM,          /**< AES cipher with 256-bit CCM mode. */
149     MBEDTLS_CIPHER_CAMELLIA_128_CCM,     /**< Camellia cipher with 128-bit CCM mode. */
150     MBEDTLS_CIPHER_CAMELLIA_192_CCM,     /**< Camellia cipher with 192-bit CCM mode. */
151     MBEDTLS_CIPHER_CAMELLIA_256_CCM,     /**< Camellia cipher with 256-bit CCM mode. */
152     MBEDTLS_CIPHER_ARIA_128_ECB,         /**< Aria cipher with 128-bit key and ECB mode. */
153     MBEDTLS_CIPHER_ARIA_192_ECB,         /**< Aria cipher with 192-bit key and ECB mode. */
154     MBEDTLS_CIPHER_ARIA_256_ECB,         /**< Aria cipher with 256-bit key and ECB mode. */
155     MBEDTLS_CIPHER_ARIA_128_CBC,         /**< Aria cipher with 128-bit key and CBC mode. */
156     MBEDTLS_CIPHER_ARIA_192_CBC,         /**< Aria cipher with 192-bit key and CBC mode. */
157     MBEDTLS_CIPHER_ARIA_256_CBC,         /**< Aria cipher with 256-bit key and CBC mode. */
158     MBEDTLS_CIPHER_ARIA_128_CFB128,      /**< Aria cipher with 128-bit key and CFB-128 mode. */
159     MBEDTLS_CIPHER_ARIA_192_CFB128,      /**< Aria cipher with 192-bit key and CFB-128 mode. */
160     MBEDTLS_CIPHER_ARIA_256_CFB128,      /**< Aria cipher with 256-bit key and CFB-128 mode. */
161     MBEDTLS_CIPHER_ARIA_128_CTR,         /**< Aria cipher with 128-bit key and CTR mode. */
162     MBEDTLS_CIPHER_ARIA_192_CTR,         /**< Aria cipher with 192-bit key and CTR mode. */
163     MBEDTLS_CIPHER_ARIA_256_CTR,         /**< Aria cipher with 256-bit key and CTR mode. */
164     MBEDTLS_CIPHER_ARIA_128_GCM,         /**< Aria cipher with 128-bit key and GCM mode. */
165     MBEDTLS_CIPHER_ARIA_192_GCM,         /**< Aria cipher with 192-bit key and GCM mode. */
166     MBEDTLS_CIPHER_ARIA_256_GCM,         /**< Aria cipher with 256-bit key and GCM mode. */
167     MBEDTLS_CIPHER_ARIA_128_CCM,         /**< Aria cipher with 128-bit key and CCM mode. */
168     MBEDTLS_CIPHER_ARIA_192_CCM,         /**< Aria cipher with 192-bit key and CCM mode. */
169     MBEDTLS_CIPHER_ARIA_256_CCM,         /**< Aria cipher with 256-bit key and CCM mode. */
170     MBEDTLS_CIPHER_AES_128_OFB,          /**< AES 128-bit cipher in OFB mode. */
171     MBEDTLS_CIPHER_AES_192_OFB,          /**< AES 192-bit cipher in OFB mode. */
172     MBEDTLS_CIPHER_AES_256_OFB,          /**< AES 256-bit cipher in OFB mode. */
173     MBEDTLS_CIPHER_AES_128_XTS,          /**< AES 128-bit cipher in XTS block mode. */
174     MBEDTLS_CIPHER_AES_256_XTS,          /**< AES 256-bit cipher in XTS block mode. */
175     MBEDTLS_CIPHER_CHACHA20,             /**< ChaCha20 stream cipher. */
176     MBEDTLS_CIPHER_CHACHA20_POLY1305,    /**< ChaCha20-Poly1305 AEAD cipher. */
177     MBEDTLS_CIPHER_AES_128_KW,           /**< AES cipher with 128-bit NIST KW mode. */
178     MBEDTLS_CIPHER_AES_192_KW,           /**< AES cipher with 192-bit NIST KW mode. */
179     MBEDTLS_CIPHER_AES_256_KW,           /**< AES cipher with 256-bit NIST KW mode. */
180     MBEDTLS_CIPHER_AES_128_KWP,          /**< AES cipher with 128-bit NIST KWP mode. */
181     MBEDTLS_CIPHER_AES_192_KWP,          /**< AES cipher with 192-bit NIST KWP mode. */
182     MBEDTLS_CIPHER_AES_256_KWP,          /**< AES cipher with 256-bit NIST KWP mode. */
183 } mbedtls_cipher_type_t;
184 
185 /** Supported cipher modes. */
186 typedef enum {
187     MBEDTLS_MODE_NONE = 0,               /**< None.                        */
188     MBEDTLS_MODE_ECB,                    /**< The ECB cipher mode.         */
189     MBEDTLS_MODE_CBC,                    /**< The CBC cipher mode.         */
190     MBEDTLS_MODE_CFB,                    /**< The CFB cipher mode.         */
191     MBEDTLS_MODE_OFB,                    /**< The OFB cipher mode.         */
192     MBEDTLS_MODE_CTR,                    /**< The CTR cipher mode.         */
193     MBEDTLS_MODE_GCM,                    /**< The GCM cipher mode.         */
194     MBEDTLS_MODE_STREAM,                 /**< The stream cipher mode.      */
195     MBEDTLS_MODE_CCM,                    /**< The CCM cipher mode.         */
196     MBEDTLS_MODE_XTS,                    /**< The XTS cipher mode.         */
197     MBEDTLS_MODE_CHACHAPOLY,             /**< The ChaCha-Poly cipher mode. */
198     MBEDTLS_MODE_KW,                     /**< The SP800-38F KW mode */
199     MBEDTLS_MODE_KWP,                    /**< The SP800-38F KWP mode */
200 } mbedtls_cipher_mode_t;
201 
202 /** Supported cipher padding types. */
203 typedef enum {
204     MBEDTLS_PADDING_PKCS7 = 0,     /**< PKCS7 padding (default).        */
205     MBEDTLS_PADDING_ONE_AND_ZEROS, /**< ISO/IEC 7816-4 padding.         */
206     MBEDTLS_PADDING_ZEROS_AND_LEN, /**< ANSI X.923 padding.             */
207     MBEDTLS_PADDING_ZEROS,         /**< Zero padding (not reversible). */
208     MBEDTLS_PADDING_NONE,          /**< Never pad (full blocks only).   */
209 } mbedtls_cipher_padding_t;
210 
211 /** Type of operation. */
212 typedef enum {
213     MBEDTLS_OPERATION_NONE = -1,
214     MBEDTLS_DECRYPT = 0,
215     MBEDTLS_ENCRYPT,
216 } mbedtls_operation_t;
217 
218 enum {
219     /** Undefined key length. */
220     MBEDTLS_KEY_LENGTH_NONE = 0,
221     /** Key length, in bits (including parity), for DES keys. */
222     MBEDTLS_KEY_LENGTH_DES  = 64,
223     /** Key length in bits, including parity, for DES in two-key EDE. */
224     MBEDTLS_KEY_LENGTH_DES_EDE = 128,
225     /** Key length in bits, including parity, for DES in three-key EDE. */
226     MBEDTLS_KEY_LENGTH_DES_EDE3 = 192,
227 };
228 
229 /** Maximum length of any IV, in Bytes. */
230 /* This should ideally be derived automatically from list of ciphers.
231  * This should be kept in sync with MBEDTLS_SSL_MAX_IV_LENGTH defined
232  * in ssl_internal.h. */
233 #define MBEDTLS_MAX_IV_LENGTH      16
234 
235 /** Maximum block size of any cipher, in Bytes. */
236 /* This should ideally be derived automatically from list of ciphers.
237  * This should be kept in sync with MBEDTLS_SSL_MAX_BLOCK_LENGTH defined
238  * in ssl_internal.h. */
239 #define MBEDTLS_MAX_BLOCK_LENGTH   16
240 
241 /** Maximum key length, in Bytes. */
242 /* This should ideally be derived automatically from list of ciphers.
243  * For now, only check whether XTS is enabled which uses 64 Byte keys,
244  * and use 32 Bytes as an upper bound for the maximum key length otherwise.
245  * This should be kept in sync with MBEDTLS_SSL_MAX_BLOCK_LENGTH defined
246  * in ssl_internal.h, which however deliberately ignores the case of XTS
247  * since the latter isn't used in SSL/TLS. */
248 #if defined(MBEDTLS_CIPHER_MODE_XTS)
249 #define MBEDTLS_MAX_KEY_LENGTH     64
250 #else
251 #define MBEDTLS_MAX_KEY_LENGTH     32
252 #endif /* MBEDTLS_CIPHER_MODE_XTS */
253 
254 /**
255  * Base cipher information (opaque struct).
256  */
257 typedef struct mbedtls_cipher_base_t mbedtls_cipher_base_t;
258 
259 /**
260  * CMAC context (opaque struct).
261  */
262 typedef struct mbedtls_cmac_context_t mbedtls_cmac_context_t;
263 
264 /**
265  * Cipher information. Allows calling cipher functions
266  * in a generic way.
267  */
268 typedef struct mbedtls_cipher_info_t
269 {
270     /** Full cipher identifier. For example,
271      * MBEDTLS_CIPHER_AES_256_CBC.
272      */
273     mbedtls_cipher_type_t type;
274 
275     /** The cipher mode. For example, MBEDTLS_MODE_CBC. */
276     mbedtls_cipher_mode_t mode;
277 
278     /** The cipher key length, in bits. This is the
279      * default length for variable sized ciphers.
280      * Includes parity bits for ciphers like DES.
281      */
282     unsigned int key_bitlen;
283 
284     /** Name of the cipher. */
285     const char * name;
286 
287     /** IV or nonce size, in Bytes.
288      * For ciphers that accept variable IV sizes,
289      * this is the recommended size.
290      */
291     unsigned int iv_size;
292 
293     /** Bitflag comprised of MBEDTLS_CIPHER_VARIABLE_IV_LEN and
294      *  MBEDTLS_CIPHER_VARIABLE_KEY_LEN indicating whether the
295      *  cipher supports variable IV or variable key sizes, respectively.
296      */
297     int flags;
298 
299     /** The block size, in Bytes. */
300     unsigned int block_size;
301 
302     /** Struct for base cipher information and functions. */
303     const mbedtls_cipher_base_t *base;
304 
305 } mbedtls_cipher_info_t;
306 
307 /**
308  * Generic cipher context.
309  */
310 typedef struct mbedtls_cipher_context_t
311 {
312     /** Information about the associated cipher. */
313     const mbedtls_cipher_info_t *cipher_info;
314 
315     /** Key length to use. */
316     int key_bitlen;
317 
318     /** Operation that the key of the context has been
319      * initialized for.
320      */
321     mbedtls_operation_t operation;
322 
323 #if defined(MBEDTLS_CIPHER_MODE_WITH_PADDING)
324     /** Padding functions to use, if relevant for
325      * the specific cipher mode.
326      */
327     void (*add_padding)( unsigned char *output, size_t olen, size_t data_len );
328     int (*get_padding)( unsigned char *input, size_t ilen, size_t *data_len );
329 #endif
330 
331     /** Buffer for input that has not been processed yet. */
332     unsigned char unprocessed_data[MBEDTLS_MAX_BLOCK_LENGTH];
333 
334     /** Number of Bytes that have not been processed yet. */
335     size_t unprocessed_len;
336 
337     /** Current IV or NONCE_COUNTER for CTR-mode, data unit (or sector) number
338      * for XTS-mode. */
339     unsigned char iv[MBEDTLS_MAX_IV_LENGTH];
340 
341     /** IV size in Bytes, for ciphers with variable-length IVs. */
342     size_t iv_size;
343 
344     /** The cipher-specific context. */
345     void *cipher_ctx;
346 
347 #if defined(MBEDTLS_CMAC_C)
348     /** CMAC-specific context. */
349     mbedtls_cmac_context_t *cmac_ctx;
350 #endif
351 
352 #if defined(MBEDTLS_USE_PSA_CRYPTO)
353     /** Indicates whether the cipher operations should be performed
354      *  by Mbed TLS' own crypto library or an external implementation
355      *  of the PSA Crypto API.
356      *  This is unset if the cipher context was established through
357      *  mbedtls_cipher_setup(), and set if it was established through
358      *  mbedtls_cipher_setup_psa().
359      */
360     unsigned char psa_enabled;
361 #endif /* MBEDTLS_USE_PSA_CRYPTO */
362 
363 } mbedtls_cipher_context_t;
364 
365 /**
366  * \brief This function retrieves the list of ciphers supported
367  *        by the generic cipher module.
368  *
369  *        For any cipher identifier in the returned list, you can
370  *        obtain the corresponding generic cipher information structure
371  *        via mbedtls_cipher_info_from_type(), which can then be used
372  *        to prepare a cipher context via mbedtls_cipher_setup().
373  *
374  *
375  * \return      A statically-allocated array of cipher identifiers
376  *              of type cipher_type_t. The last entry is zero.
377  */
378 const int *mbedtls_cipher_list( void );
379 
380 /**
381  * \brief               This function retrieves the cipher-information
382  *                      structure associated with the given cipher name.
383  *
384  * \param cipher_name   Name of the cipher to search for. This must not be
385  *                      \c NULL.
386  *
387  * \return              The cipher information structure associated with the
388  *                      given \p cipher_name.
389  * \return              \c NULL if the associated cipher information is not found.
390  */
391 const mbedtls_cipher_info_t *mbedtls_cipher_info_from_string( const char *cipher_name );
392 
393 /**
394  * \brief               This function retrieves the cipher-information
395  *                      structure associated with the given cipher type.
396  *
397  * \param cipher_type   Type of the cipher to search for.
398  *
399  * \return              The cipher information structure associated with the
400  *                      given \p cipher_type.
401  * \return              \c NULL if the associated cipher information is not found.
402  */
403 const mbedtls_cipher_info_t *mbedtls_cipher_info_from_type( const mbedtls_cipher_type_t cipher_type );
404 
405 /**
406  * \brief               This function retrieves the cipher-information
407  *                      structure associated with the given cipher ID,
408  *                      key size and mode.
409  *
410  * \param cipher_id     The ID of the cipher to search for. For example,
411  *                      #MBEDTLS_CIPHER_ID_AES.
412  * \param key_bitlen    The length of the key in bits.
413  * \param mode          The cipher mode. For example, #MBEDTLS_MODE_CBC.
414  *
415  * \return              The cipher information structure associated with the
416  *                      given \p cipher_id.
417  * \return              \c NULL if the associated cipher information is not found.
418  */
419 const mbedtls_cipher_info_t *mbedtls_cipher_info_from_values( const mbedtls_cipher_id_t cipher_id,
420                                               int key_bitlen,
421                                               const mbedtls_cipher_mode_t mode );
422 
423 /**
424  * \brief               This function initializes a \p cipher_context as NONE.
425  *
426  * \param ctx           The context to be initialized. This must not be \c NULL.
427  */
428 void mbedtls_cipher_init( mbedtls_cipher_context_t *ctx );
429 
430 /**
431  * \brief               This function frees and clears the cipher-specific
432  *                      context of \p ctx. Freeing \p ctx itself remains the
433  *                      responsibility of the caller.
434  *
435  * \param ctx           The context to be freed. If this is \c NULL, the
436  *                      function has no effect, otherwise this must point to an
437  *                      initialized context.
438  */
439 void mbedtls_cipher_free( mbedtls_cipher_context_t *ctx );
440 
441 /**
442  * \brief           Clone the state of an cipher context
443  *
444  * \note            The two contexts must have been setup to the same type
445  *                  (cloning from AES to DES make no sense).
446  *
447  * \param dst       The destination context
448  * \param src       The context to be cloned
449  *
450  * \return          \c 0 on success,
451  *                  \c MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on parameter failure.
452  */
453 int mbedtls_cipher_clone( mbedtls_cipher_context_t *dst,
454                           const mbedtls_cipher_context_t *src );
455 
456 /**
457  * \brief               This function initializes a cipher context for
458  *                      use with the given cipher primitive.
459  *
460  * \param ctx           The context to initialize. This must be initialized.
461  * \param cipher_info   The cipher to use.
462  *
463  * \return              \c 0 on success.
464  * \return              #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
465  *                      parameter-verification failure.
466  * \return              #MBEDTLS_ERR_CIPHER_ALLOC_FAILED if allocation of the
467  *                      cipher-specific context fails.
468  *
469  * \internal Currently, the function also clears the structure.
470  * In future versions, the caller will be required to call
471  * mbedtls_cipher_init() on the structure first.
472  */
473 int mbedtls_cipher_setup( mbedtls_cipher_context_t *ctx,
474                           const mbedtls_cipher_info_t *cipher_info );
475 
476 #if defined(MBEDTLS_USE_PSA_CRYPTO)
477 /**
478  * \brief               This function initializes a cipher context for
479  *                      PSA-based use with the given cipher primitive.
480  *
481  * \note                See #MBEDTLS_USE_PSA_CRYPTO for information on PSA.
482  *
483  * \param ctx           The context to initialize. May not be \c NULL.
484  * \param cipher_info   The cipher to use.
485  * \param taglen        For AEAD ciphers, the length in bytes of the
486  *                      authentication tag to use. Subsequent uses of
487  *                      mbedtls_cipher_auth_encrypt() or
488  *                      mbedtls_cipher_auth_decrypt() must provide
489  *                      the same tag length.
490  *                      For non-AEAD ciphers, the value must be \c 0.
491  *
492  * \return              \c 0 on success.
493  * \return              #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
494  *                      parameter-verification failure.
495  * \return              #MBEDTLS_ERR_CIPHER_ALLOC_FAILED if allocation of the
496  *                      cipher-specific context fails.
497  */
498 int mbedtls_cipher_setup_psa( mbedtls_cipher_context_t *ctx,
499                               const mbedtls_cipher_info_t *cipher_info,
500                               size_t taglen );
501 #endif /* MBEDTLS_USE_PSA_CRYPTO */
502 
503 /**
504  * \brief               setup the cipher info structure.
505  *
506  * \param ctx           cipher's context. Must have been initialised.
507  * \param cipher_info   cipher to use.
508  *
509  * \return              0 on success,
510  *                      MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on parameter failure
511  */
512 int mbedtls_cipher_setup_info( mbedtls_cipher_context_t *ctx, const mbedtls_cipher_info_t *cipher_info );
513 
514 /**
515  * \brief        This function returns the block size of the given cipher.
516  *
517  * \param ctx    The context of the cipher. This must be initialized.
518  *
519  * \return       The block size of the underlying cipher.
520  * \return       \c 0 if \p ctx has not been initialized.
521  */
mbedtls_cipher_get_block_size(const mbedtls_cipher_context_t * ctx)522 static inline unsigned int mbedtls_cipher_get_block_size(
523     const mbedtls_cipher_context_t *ctx )
524 {
525     MBEDTLS_INTERNAL_VALIDATE_RET( ctx != NULL, 0 );
526     if( ctx->cipher_info == NULL )
527         return 0;
528 
529     return ctx->cipher_info->block_size;
530 }
531 
532 /**
533  * \brief        This function returns the mode of operation for
534  *               the cipher. For example, MBEDTLS_MODE_CBC.
535  *
536  * \param ctx    The context of the cipher. This must be initialized.
537  *
538  * \return       The mode of operation.
539  * \return       #MBEDTLS_MODE_NONE if \p ctx has not been initialized.
540  */
mbedtls_cipher_get_cipher_mode(const mbedtls_cipher_context_t * ctx)541 static inline mbedtls_cipher_mode_t mbedtls_cipher_get_cipher_mode(
542     const mbedtls_cipher_context_t *ctx )
543 {
544     MBEDTLS_INTERNAL_VALIDATE_RET( ctx != NULL, MBEDTLS_MODE_NONE );
545     if( ctx->cipher_info == NULL )
546         return MBEDTLS_MODE_NONE;
547 
548     return ctx->cipher_info->mode;
549 }
550 
551 /**
552  * \brief       This function returns the size of the IV or nonce
553  *              of the cipher, in Bytes.
554  *
555  * \param ctx   The context of the cipher. This must be initialized.
556  *
557  * \return      The recommended IV size if no IV has been set.
558  * \return      \c 0 for ciphers not using an IV or a nonce.
559  * \return      The actual size if an IV has been set.
560  */
mbedtls_cipher_get_iv_size(const mbedtls_cipher_context_t * ctx)561 static inline int mbedtls_cipher_get_iv_size(
562     const mbedtls_cipher_context_t *ctx )
563 {
564     MBEDTLS_INTERNAL_VALIDATE_RET( ctx != NULL, 0 );
565     if( ctx->cipher_info == NULL )
566         return 0;
567 
568     if( ctx->iv_size != 0 )
569         return (int) ctx->iv_size;
570 
571     return (int) ctx->cipher_info->iv_size;
572 }
573 
574 /**
575  * \brief               This function returns the type of the given cipher.
576  *
577  * \param ctx           The context of the cipher. This must be initialized.
578  *
579  * \return              The type of the cipher.
580  * \return              #MBEDTLS_CIPHER_NONE if \p ctx has not been initialized.
581  */
mbedtls_cipher_get_type(const mbedtls_cipher_context_t * ctx)582 static inline mbedtls_cipher_type_t mbedtls_cipher_get_type(
583     const mbedtls_cipher_context_t *ctx )
584 {
585     MBEDTLS_INTERNAL_VALIDATE_RET(
586         ctx != NULL, MBEDTLS_CIPHER_NONE );
587     if( ctx->cipher_info == NULL )
588         return MBEDTLS_CIPHER_NONE;
589 
590     return ctx->cipher_info->type;
591 }
592 
593 /**
594  * \brief               This function returns the name of the given cipher
595  *                      as a string.
596  *
597  * \param ctx           The context of the cipher. This must be initialized.
598  *
599  * \return              The name of the cipher.
600  * \return              NULL if \p ctx has not been not initialized.
601  */
mbedtls_cipher_get_name(const mbedtls_cipher_context_t * ctx)602 static inline const char *mbedtls_cipher_get_name(
603     const mbedtls_cipher_context_t *ctx )
604 {
605     MBEDTLS_INTERNAL_VALIDATE_RET( ctx != NULL, 0 );
606     if( ctx->cipher_info == NULL )
607         return 0;
608 
609     return ctx->cipher_info->name;
610 }
611 
612 /**
613  * \brief               This function returns the key length of the cipher.
614  *
615  * \param ctx           The context of the cipher. This must be initialized.
616  *
617  * \return              The key length of the cipher in bits.
618  * \return              #MBEDTLS_KEY_LENGTH_NONE if ctx \p has not been
619  *                      initialized.
620  */
mbedtls_cipher_get_key_bitlen(const mbedtls_cipher_context_t * ctx)621 static inline int mbedtls_cipher_get_key_bitlen(
622     const mbedtls_cipher_context_t *ctx )
623 {
624     MBEDTLS_INTERNAL_VALIDATE_RET(
625         ctx != NULL, MBEDTLS_KEY_LENGTH_NONE );
626     if( ctx->cipher_info == NULL )
627         return MBEDTLS_KEY_LENGTH_NONE;
628 
629     return (int) ctx->cipher_info->key_bitlen;
630 }
631 
632 /**
633  * \brief          This function returns the operation of the given cipher.
634  *
635  * \param ctx      The context of the cipher. This must be initialized.
636  *
637  * \return         The type of operation: #MBEDTLS_ENCRYPT or #MBEDTLS_DECRYPT.
638  * \return         #MBEDTLS_OPERATION_NONE if \p ctx has not been initialized.
639  */
mbedtls_cipher_get_operation(const mbedtls_cipher_context_t * ctx)640 static inline mbedtls_operation_t mbedtls_cipher_get_operation(
641     const mbedtls_cipher_context_t *ctx )
642 {
643     MBEDTLS_INTERNAL_VALIDATE_RET(
644         ctx != NULL, MBEDTLS_OPERATION_NONE );
645     if( ctx->cipher_info == NULL )
646         return MBEDTLS_OPERATION_NONE;
647 
648     return ctx->operation;
649 }
650 
651 /**
652  * \brief               This function sets the key to use with the given context.
653  *
654  * \param ctx           The generic cipher context. This must be initialized and
655  *                      bound to a cipher information structure.
656  * \param key           The key to use. This must be a readable buffer of at
657  *                      least \p key_bitlen Bits.
658  * \param key_bitlen    The key length to use, in Bits.
659  * \param operation     The operation that the key will be used for:
660  *                      #MBEDTLS_ENCRYPT or #MBEDTLS_DECRYPT.
661  *
662  * \return              \c 0 on success.
663  * \return              #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
664  *                      parameter-verification failure.
665  * \return              A cipher-specific error code on failure.
666  */
667 int mbedtls_cipher_setkey( mbedtls_cipher_context_t *ctx,
668                            const unsigned char *key,
669                            int key_bitlen,
670                            const mbedtls_operation_t operation );
671 
672 #if defined(MBEDTLS_CIPHER_MODE_WITH_PADDING)
673 /**
674  * \brief               This function sets the padding mode, for cipher modes
675  *                      that use padding.
676  *
677  *                      The default passing mode is PKCS7 padding.
678  *
679  * \param ctx           The generic cipher context. This must be initialized and
680  *                      bound to a cipher information structure.
681  * \param mode          The padding mode.
682  *
683  * \return              \c 0 on success.
684  * \return              #MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE
685  *                      if the selected padding mode is not supported.
686  * \return              #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA if the cipher mode
687  *                      does not support padding.
688  */
689 int mbedtls_cipher_set_padding_mode( mbedtls_cipher_context_t *ctx,
690                                      mbedtls_cipher_padding_t mode );
691 #endif /* MBEDTLS_CIPHER_MODE_WITH_PADDING */
692 
693 /**
694  * \brief           This function sets the initialization vector (IV)
695  *                  or nonce.
696  *
697  * \note            Some ciphers do not use IVs nor nonce. For these
698  *                  ciphers, this function has no effect.
699  *
700  * \param ctx       The generic cipher context. This must be initialized and
701  *                  bound to a cipher information structure.
702  * \param iv        The IV to use, or NONCE_COUNTER for CTR-mode ciphers. This
703  *                  must be a readable buffer of at least \p iv_len Bytes.
704  * \param iv_len    The IV length for ciphers with variable-size IV.
705  *                  This parameter is discarded by ciphers with fixed-size IV.
706  *
707  * \return          \c 0 on success.
708  * \return          #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
709  *                  parameter-verification failure.
710  */
711 int mbedtls_cipher_set_iv( mbedtls_cipher_context_t *ctx,
712                            const unsigned char *iv,
713                            size_t iv_len );
714 
715 /**
716  * \brief         This function resets the cipher state.
717  *
718  * \param ctx     The generic cipher context. This must be initialized.
719  *
720  * \return        \c 0 on success.
721  * \return        #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
722  *                parameter-verification failure.
723  */
724 int mbedtls_cipher_reset( mbedtls_cipher_context_t *ctx );
725 
726 #if defined(MBEDTLS_GCM_C) || defined(MBEDTLS_CHACHAPOLY_C)
727 /**
728  * \brief               This function adds additional data for AEAD ciphers.
729  *                      Currently supported with GCM and ChaCha20+Poly1305.
730  *                      This must be called exactly once, after
731  *                      mbedtls_cipher_reset().
732  *
733  * \param ctx           The generic cipher context. This must be initialized.
734  * \param ad            The additional data to use. This must be a readable
735  *                      buffer of at least \p ad_len Bytes.
736  * \param ad_len        The length of \p ad in Bytes.
737  *
738  * \return              \c 0 on success.
739  * \return              A specific error code on failure.
740  */
741 int mbedtls_cipher_update_ad( mbedtls_cipher_context_t *ctx,
742                       const unsigned char *ad, size_t ad_len );
743 #endif /* MBEDTLS_GCM_C || MBEDTLS_CHACHAPOLY_C */
744 
745 /**
746  * \brief               The generic cipher update function. It encrypts or
747  *                      decrypts using the given cipher context. Writes as
748  *                      many block-sized blocks of data as possible to output.
749  *                      Any data that cannot be written immediately is either
750  *                      added to the next block, or flushed when
751  *                      mbedtls_cipher_finish() is called.
752  *                      Exception: For MBEDTLS_MODE_ECB, expects a single block
753  *                      in size. For example, 16 Bytes for AES.
754  *
755  * \note                If the underlying cipher is used in GCM mode, all calls
756  *                      to this function, except for the last one before
757  *                      mbedtls_cipher_finish(), must have \p ilen as a
758  *                      multiple of the block size of the cipher.
759  *
760  * \param ctx           The generic cipher context. This must be initialized and
761  *                      bound to a key.
762  * \param input         The buffer holding the input data. This must be a
763  *                      readable buffer of at least \p ilen Bytes.
764  * \param ilen          The length of the input data.
765  * \param output        The buffer for the output data. This must be able to
766  *                      hold at least `ilen + block_size`. This must not be the
767  *                      same buffer as \p input.
768  * \param olen          The length of the output data, to be updated with the
769  *                      actual number of Bytes written. This must not be
770  *                      \c NULL.
771  *
772  * \return              \c 0 on success.
773  * \return              #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
774  *                      parameter-verification failure.
775  * \return              #MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE on an
776  *                      unsupported mode for a cipher.
777  * \return              A cipher-specific error code on failure.
778  */
779 int mbedtls_cipher_update( mbedtls_cipher_context_t *ctx,
780                            const unsigned char *input,
781                            size_t ilen, unsigned char *output,
782                            size_t *olen );
783 
784 /**
785  * \brief               The generic cipher finalization function. If data still
786  *                      needs to be flushed from an incomplete block, the data
787  *                      contained in it is padded to the size of
788  *                      the last block, and written to the \p output buffer.
789  *
790  * \param ctx           The generic cipher context. This must be initialized and
791  *                      bound to a key.
792  * \param output        The buffer to write data to. This needs to be a writable
793  *                      buffer of at least \p block_size Bytes.
794  * \param olen          The length of the data written to the \p output buffer.
795  *                      This may not be \c NULL.
796  *
797  * \return              \c 0 on success.
798  * \return              #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
799  *                      parameter-verification failure.
800  * \return              #MBEDTLS_ERR_CIPHER_FULL_BLOCK_EXPECTED on decryption
801  *                      expecting a full block but not receiving one.
802  * \return              #MBEDTLS_ERR_CIPHER_INVALID_PADDING on invalid padding
803  *                      while decrypting.
804  * \return              A cipher-specific error code on failure.
805  */
806 int mbedtls_cipher_finish( mbedtls_cipher_context_t *ctx,
807                    unsigned char *output, size_t *olen );
808 
809 #if defined(MBEDTLS_GCM_C) || defined(MBEDTLS_CHACHAPOLY_C)
810 /**
811  * \brief               This function writes a tag for AEAD ciphers.
812  *                      Currently supported with GCM and ChaCha20+Poly1305.
813  *                      This must be called after mbedtls_cipher_finish().
814  *
815  * \param ctx           The generic cipher context. This must be initialized,
816  *                      bound to a key, and have just completed a cipher
817  *                      operation through mbedtls_cipher_finish() the tag for
818  *                      which should be written.
819  * \param tag           The buffer to write the tag to. This must be a writable
820  *                      buffer of at least \p tag_len Bytes.
821  * \param tag_len       The length of the tag to write.
822  *
823  * \return              \c 0 on success.
824  * \return              A specific error code on failure.
825  */
826 int mbedtls_cipher_write_tag( mbedtls_cipher_context_t *ctx,
827                       unsigned char *tag, size_t tag_len );
828 
829 /**
830  * \brief               This function checks the tag for AEAD ciphers.
831  *                      Currently supported with GCM and ChaCha20+Poly1305.
832  *                      This must be called after mbedtls_cipher_finish().
833  *
834  * \param ctx           The generic cipher context. This must be initialized.
835  * \param tag           The buffer holding the tag. This must be a readable
836  *                      buffer of at least \p tag_len Bytes.
837  * \param tag_len       The length of the tag to check.
838  *
839  * \return              \c 0 on success.
840  * \return              A specific error code on failure.
841  */
842 int mbedtls_cipher_check_tag( mbedtls_cipher_context_t *ctx,
843                       const unsigned char *tag, size_t tag_len );
844 #endif /* MBEDTLS_GCM_C || MBEDTLS_CHACHAPOLY_C */
845 
846 /**
847  * \brief               The generic all-in-one encryption/decryption function,
848  *                      for all ciphers except AEAD constructs.
849  *
850  * \param ctx           The generic cipher context. This must be initialized.
851  * \param iv            The IV to use, or NONCE_COUNTER for CTR-mode ciphers.
852  *                      This must be a readable buffer of at least \p iv_len
853  *                      Bytes.
854  * \param iv_len        The IV length for ciphers with variable-size IV.
855  *                      This parameter is discarded by ciphers with fixed-size
856  *                      IV.
857  * \param input         The buffer holding the input data. This must be a
858  *                      readable buffer of at least \p ilen Bytes.
859  * \param ilen          The length of the input data in Bytes.
860  * \param output        The buffer for the output data. This must be able to
861  *                      hold at least `ilen + block_size`. This must not be the
862  *                      same buffer as \p input.
863  * \param olen          The length of the output data, to be updated with the
864  *                      actual number of Bytes written. This must not be
865  *                      \c NULL.
866  *
867  * \note                Some ciphers do not use IVs nor nonce. For these
868  *                      ciphers, use \p iv = NULL and \p iv_len = 0.
869  *
870  * \return              \c 0 on success.
871  * \return              #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
872  *                      parameter-verification failure.
873  * \return              #MBEDTLS_ERR_CIPHER_FULL_BLOCK_EXPECTED on decryption
874  *                      expecting a full block but not receiving one.
875  * \return              #MBEDTLS_ERR_CIPHER_INVALID_PADDING on invalid padding
876  *                      while decrypting.
877  * \return              A cipher-specific error code on failure.
878  */
879 int mbedtls_cipher_crypt( mbedtls_cipher_context_t *ctx,
880                   const unsigned char *iv, size_t iv_len,
881                   const unsigned char *input, size_t ilen,
882                   unsigned char *output, size_t *olen );
883 
884 #if defined(MBEDTLS_CIPHER_MODE_AEAD)
885 #if ! defined(MBEDTLS_DEPRECATED_REMOVED)
886 #if defined(MBEDTLS_DEPRECATED_WARNING)
887 #define MBEDTLS_DEPRECATED    __attribute__((deprecated))
888 #else
889 #define MBEDTLS_DEPRECATED
890 #endif /* MBEDTLS_DEPRECATED_WARNING */
891 /**
892  * \brief               The generic authenticated encryption (AEAD) function.
893  *
894  * \deprecated          Superseded by mbedtls_cipher_auth_encrypt_ext().
895  *
896  * \note                This function only supports AEAD algorithms, not key
897  *                      wrapping algorithms such as NIST_KW; for this, see
898  *                      mbedtls_cipher_auth_encrypt_ext().
899  *
900  * \param ctx           The generic cipher context. This must be initialized and
901  *                      bound to a key associated with an AEAD algorithm.
902  * \param iv            The nonce to use. This must be a readable buffer of
903  *                      at least \p iv_len Bytes and must not be \c NULL.
904  * \param iv_len        The length of the nonce. This must satisfy the
905  *                      constraints imposed by the AEAD cipher used.
906  * \param ad            The additional data to authenticate. This must be a
907  *                      readable buffer of at least \p ad_len Bytes, and may
908  *                      be \c NULL is \p ad_len is \c 0.
909  * \param ad_len        The length of \p ad.
910  * \param input         The buffer holding the input data. This must be a
911  *                      readable buffer of at least \p ilen Bytes, and may be
912  *                      \c NULL if \p ilen is \c 0.
913  * \param ilen          The length of the input data.
914  * \param output        The buffer for the output data. This must be a
915  *                      writable buffer of at least \p ilen Bytes, and must
916  *                      not be \c NULL.
917  * \param olen          This will be filled with the actual number of Bytes
918  *                      written to the \p output buffer. This must point to a
919  *                      writable object of type \c size_t.
920  * \param tag           The buffer for the authentication tag. This must be a
921  *                      writable buffer of at least \p tag_len Bytes. See note
922  *                      below regarding restrictions with PSA-based contexts.
923  * \param tag_len       The desired length of the authentication tag. This
924  *                      must match the constraints imposed by the AEAD cipher
925  *                      used, and in particular must not be \c 0.
926  *
927  * \note                If the context is based on PSA (that is, it was set up
928  *                      with mbedtls_cipher_setup_psa()), then it is required
929  *                      that \c tag == output + ilen. That is, the tag must be
930  *                      appended to the ciphertext as recommended by RFC 5116.
931  *
932  * \return              \c 0 on success.
933  * \return              #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
934  *                      parameter-verification failure.
935  * \return              A cipher-specific error code on failure.
936  */
937 int mbedtls_cipher_auth_encrypt( mbedtls_cipher_context_t *ctx,
938                          const unsigned char *iv, size_t iv_len,
939                          const unsigned char *ad, size_t ad_len,
940                          const unsigned char *input, size_t ilen,
941                          unsigned char *output, size_t *olen,
942                          unsigned char *tag, size_t tag_len )
943                          MBEDTLS_DEPRECATED;
944 
945 /**
946  * \brief               The generic authenticated decryption (AEAD) function.
947  *
948  * \deprecated          Superseded by mbedtls_cipher_auth_decrypt_ext().
949  *
950  * \note                This function only supports AEAD algorithms, not key
951  *                      wrapping algorithms such as NIST_KW; for this, see
952  *                      mbedtls_cipher_auth_decrypt_ext().
953  *
954  * \note                If the data is not authentic, then the output buffer
955  *                      is zeroed out to prevent the unauthentic plaintext being
956  *                      used, making this interface safer.
957  *
958  * \param ctx           The generic cipher context. This must be initialized and
959  *                      bound to a key associated with an AEAD algorithm.
960  * \param iv            The nonce to use. This must be a readable buffer of
961  *                      at least \p iv_len Bytes and must not be \c NULL.
962  * \param iv_len        The length of the nonce. This must satisfy the
963  *                      constraints imposed by the AEAD cipher used.
964  * \param ad            The additional data to authenticate. This must be a
965  *                      readable buffer of at least \p ad_len Bytes, and may
966  *                      be \c NULL is \p ad_len is \c 0.
967  * \param ad_len        The length of \p ad.
968  * \param input         The buffer holding the input data. This must be a
969  *                      readable buffer of at least \p ilen Bytes, and may be
970  *                      \c NULL if \p ilen is \c 0.
971  * \param ilen          The length of the input data.
972  * \param output        The buffer for the output data. This must be a
973  *                      writable buffer of at least \p ilen Bytes, and must
974  *                      not be \c NULL.
975  * \param olen          This will be filled with the actual number of Bytes
976  *                      written to the \p output buffer. This must point to a
977  *                      writable object of type \c size_t.
978  * \param tag           The buffer for the authentication tag. This must be a
979  *                      readable buffer of at least \p tag_len Bytes. See note
980  *                      below regarding restrictions with PSA-based contexts.
981  * \param tag_len       The length of the authentication tag. This must match
982  *                      the constraints imposed by the AEAD cipher used, and in
983  *                      particular must not be \c 0.
984  *
985  * \note                If the context is based on PSA (that is, it was set up
986  *                      with mbedtls_cipher_setup_psa()), then it is required
987  *                      that \c tag == input + len. That is, the tag must be
988  *                      appended to the ciphertext as recommended by RFC 5116.
989  *
990  * \return              \c 0 on success.
991  * \return              #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
992  *                      parameter-verification failure.
993  * \return              #MBEDTLS_ERR_CIPHER_AUTH_FAILED if data is not authentic.
994  * \return              A cipher-specific error code on failure.
995  */
996 int mbedtls_cipher_auth_decrypt( mbedtls_cipher_context_t *ctx,
997                          const unsigned char *iv, size_t iv_len,
998                          const unsigned char *ad, size_t ad_len,
999                          const unsigned char *input, size_t ilen,
1000                          unsigned char *output, size_t *olen,
1001                          const unsigned char *tag, size_t tag_len )
1002                          MBEDTLS_DEPRECATED;
1003 #undef MBEDTLS_DEPRECATED
1004 #endif /* MBEDTLS_DEPRECATED_REMOVED */
1005 #endif /* MBEDTLS_CIPHER_MODE_AEAD */
1006 
1007 #if defined(MBEDTLS_CIPHER_MODE_AEAD) || defined(MBEDTLS_NIST_KW_C)
1008 /**
1009  * \brief               The authenticated encryption (AEAD/NIST_KW) function.
1010  *
1011  * \note                For AEAD modes, the tag will be appended to the
1012  *                      ciphertext, as recommended by RFC 5116.
1013  *                      (NIST_KW doesn't have a separate tag.)
1014  *
1015  * \param ctx           The generic cipher context. This must be initialized and
1016  *                      bound to a key, with an AEAD algorithm or NIST_KW.
1017  * \param iv            The nonce to use. This must be a readable buffer of
1018  *                      at least \p iv_len Bytes and may be \c NULL if \p
1019  *                      iv_len is \c 0.
1020  * \param iv_len        The length of the nonce. For AEAD ciphers, this must
1021  *                      satisfy the constraints imposed by the cipher used.
1022  *                      For NIST_KW, this must be \c 0.
1023  * \param ad            The additional data to authenticate. This must be a
1024  *                      readable buffer of at least \p ad_len Bytes, and may
1025  *                      be \c NULL is \p ad_len is \c 0.
1026  * \param ad_len        The length of \p ad. For NIST_KW, this must be \c 0.
1027  * \param input         The buffer holding the input data. This must be a
1028  *                      readable buffer of at least \p ilen Bytes, and may be
1029  *                      \c NULL if \p ilen is \c 0.
1030  * \param ilen          The length of the input data.
1031  * \param output        The buffer for the output data. This must be a
1032  *                      writable buffer of at least \p output_len Bytes, and
1033  *                      must not be \c NULL.
1034  * \param output_len    The length of the \p output buffer in Bytes. For AEAD
1035  *                      ciphers, this must be at least \p ilen + \p tag_len.
1036  *                      For NIST_KW, this must be at least \p ilen + 8
1037  *                      (rounded up to a multiple of 8 if KWP is used);
1038  *                      \p ilen + 15 is always a safe value.
1039  * \param olen          This will be filled with the actual number of Bytes
1040  *                      written to the \p output buffer. This must point to a
1041  *                      writable object of type \c size_t.
1042  * \param tag_len       The desired length of the authentication tag. For AEAD
1043  *                      ciphers, this must match the constraints imposed by
1044  *                      the cipher used, and in particular must not be \c 0.
1045  *                      For NIST_KW, this must be \c 0.
1046  *
1047  * \return              \c 0 on success.
1048  * \return              #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
1049  *                      parameter-verification failure.
1050  * \return              A cipher-specific error code on failure.
1051  */
1052 int mbedtls_cipher_auth_encrypt_ext( mbedtls_cipher_context_t *ctx,
1053                          const unsigned char *iv, size_t iv_len,
1054                          const unsigned char *ad, size_t ad_len,
1055                          const unsigned char *input, size_t ilen,
1056                          unsigned char *output, size_t output_len,
1057                          size_t *olen, size_t tag_len );
1058 
1059 /**
1060  * \brief               The authenticated encryption (AEAD/NIST_KW) function.
1061  *
1062  * \note                If the data is not authentic, then the output buffer
1063  *                      is zeroed out to prevent the unauthentic plaintext being
1064  *                      used, making this interface safer.
1065  *
1066  * \note                For AEAD modes, the tag must be appended to the
1067  *                      ciphertext, as recommended by RFC 5116.
1068  *                      (NIST_KW doesn't have a separate tag.)
1069  *
1070  * \param ctx           The generic cipher context. This must be initialized and
1071  *                      bound to a key, with an AEAD algorithm or NIST_KW.
1072  * \param iv            The nonce to use. This must be a readable buffer of
1073  *                      at least \p iv_len Bytes and may be \c NULL if \p
1074  *                      iv_len is \c 0.
1075  * \param iv_len        The length of the nonce. For AEAD ciphers, this must
1076  *                      satisfy the constraints imposed by the cipher used.
1077  *                      For NIST_KW, this must be \c 0.
1078  * \param ad            The additional data to authenticate. This must be a
1079  *                      readable buffer of at least \p ad_len Bytes, and may
1080  *                      be \c NULL is \p ad_len is \c 0.
1081  * \param ad_len        The length of \p ad. For NIST_KW, this must be \c 0.
1082  * \param input         The buffer holding the input data. This must be a
1083  *                      readable buffer of at least \p ilen Bytes, and may be
1084  *                      \c NULL if \p ilen is \c 0.
1085  * \param ilen          The length of the input data. For AEAD ciphers this
1086  *                      must be at least \p tag_len. For NIST_KW this must be
1087  *                      at least \c 8.
1088  * \param output        The buffer for the output data. This must be a
1089  *                      writable buffer of at least \p output_len Bytes, and
1090  *                      may be \c NULL if \p output_len is \c 0.
1091  * \param output_len    The length of the \p output buffer in Bytes. For AEAD
1092  *                      ciphers, this must be at least \p ilen - \p tag_len.
1093  *                      For NIST_KW, this must be at least \p ilen - 8.
1094  * \param olen          This will be filled with the actual number of Bytes
1095  *                      written to the \p output buffer. This must point to a
1096  *                      writable object of type \c size_t.
1097  * \param tag_len       The actual length of the authentication tag. For AEAD
1098  *                      ciphers, this must match the constraints imposed by
1099  *                      the cipher used, and in particular must not be \c 0.
1100  *                      For NIST_KW, this must be \c 0.
1101  *
1102  * \return              \c 0 on success.
1103  * \return              #MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA on
1104  *                      parameter-verification failure.
1105  * \return              #MBEDTLS_ERR_CIPHER_AUTH_FAILED if data is not authentic.
1106  * \return              A cipher-specific error code on failure.
1107  */
1108 int mbedtls_cipher_auth_decrypt_ext( mbedtls_cipher_context_t *ctx,
1109                          const unsigned char *iv, size_t iv_len,
1110                          const unsigned char *ad, size_t ad_len,
1111                          const unsigned char *input, size_t ilen,
1112                          unsigned char *output, size_t output_len,
1113                          size_t *olen, size_t tag_len );
1114 #endif /* MBEDTLS_CIPHER_MODE_AEAD || MBEDTLS_NIST_KW_C */
1115 #ifdef __cplusplus
1116 }
1117 #endif
1118 
1119 #endif /* MBEDTLS_CIPHER_H */
1120