Commit | Line | Data |
---|---|---|
2874c5fd | 1 | /* SPDX-License-Identifier: GPL-2.0-or-later */ |
743edf57 HX |
2 | /* |
3 | * AEAD: Authenticated Encryption with Associated Data | |
4 | * | |
b0d955ba | 5 | * Copyright (c) 2007-2015 Herbert Xu <herbert@gondor.apana.org.au> |
743edf57 HX |
6 | */ |
7 | ||
8 | #ifndef _CRYPTO_AEAD_H | |
9 | #define _CRYPTO_AEAD_H | |
10 | ||
0df4adf8 | 11 | #include <linux/atomic.h> |
244d22ff | 12 | #include <linux/container_of.h> |
743edf57 | 13 | #include <linux/crypto.h> |
3a282bd2 | 14 | #include <linux/slab.h> |
244d22ff | 15 | #include <linux/types.h> |
743edf57 | 16 | |
5d1d65f8 HX |
17 | /** |
18 | * DOC: Authenticated Encryption With Associated Data (AEAD) Cipher API | |
19 | * | |
20 | * The AEAD cipher API is used with the ciphers of type CRYPTO_ALG_TYPE_AEAD | |
21 | * (listed as type "aead" in /proc/crypto) | |
22 | * | |
23 | * The most prominent examples for this type of encryption is GCM and CCM. | |
24 | * However, the kernel supports other types of AEAD ciphers which are defined | |
25 | * with the following cipher string: | |
26 | * | |
27 | * authenc(keyed message digest, block cipher) | |
28 | * | |
29 | * For example: authenc(hmac(sha256), cbc(aes)) | |
30 | * | |
2b0c9540 AB |
31 | * The example code provided for the symmetric key cipher operation applies |
32 | * here as well. Naturally all *skcipher* symbols must be exchanged the *aead* | |
33 | * pendants discussed in the following. In addition, for the AEAD operation, | |
34 | * the aead_request_set_ad function must be used to set the pointer to the | |
35 | * associated data memory location before performing the encryption or | |
36 | * decryption operation. Another deviation from the asynchronous block cipher | |
5d1d65f8 HX |
37 | * operation is that the caller should explicitly check for -EBADMSG of the |
38 | * crypto_aead_decrypt. That error indicates an authentication error, i.e. | |
39 | * a breach in the integrity of the message. In essence, that -EBADMSG error | |
40 | * code is the key bonus an AEAD cipher has over "standard" block chaining | |
41 | * modes. | |
f6e45c24 SM |
42 | * |
43 | * Memory Structure: | |
44 | * | |
3cd54a4c EB |
45 | * The source scatterlist must contain the concatenation of |
46 | * associated data || plaintext or ciphertext. | |
f6e45c24 | 47 | * |
3cd54a4c EB |
48 | * The destination scatterlist has the same layout, except that the plaintext |
49 | * (resp. ciphertext) will grow (resp. shrink) by the authentication tag size | |
2b0c9540 AB |
50 | * during encryption (resp. decryption). The authentication tag is generated |
51 | * during the encryption operation and appended to the ciphertext. During | |
52 | * decryption, the authentication tag is consumed along with the ciphertext and | |
53 | * used to verify the integrity of the plaintext and the associated data. | |
f6e45c24 | 54 | * |
3cd54a4c EB |
55 | * In-place encryption/decryption is enabled by using the same scatterlist |
56 | * pointer for both the source and destination. | |
f6e45c24 | 57 | * |
3cd54a4c EB |
58 | * Even in the out-of-place case, space must be reserved in the destination for |
59 | * the associated data, even though it won't be written to. This makes the | |
60 | * in-place and out-of-place cases more consistent. It is permissible for the | |
61 | * "destination" associated data to alias the "source" associated data. | |
f6e45c24 | 62 | * |
3cd54a4c EB |
63 | * As with the other scatterlist crypto APIs, zero-length scatterlist elements |
64 | * are not allowed in the used part of the scatterlist. Thus, if there is no | |
65 | * associated data, the first element must point to the plaintext/ciphertext. | |
66 | * | |
67 | * To meet the needs of IPsec, a special quirk applies to rfc4106, rfc4309, | |
68 | * rfc4543, and rfc7539esp ciphers. For these ciphers, the final 'ivsize' bytes | |
69 | * of the associated data buffer must contain a second copy of the IV. This is | |
70 | * in addition to the copy passed to aead_request_set_crypt(). These two IV | |
71 | * copies must not differ; different implementations of the same algorithm may | |
72 | * behave differently in that case. Note that the algorithm might not actually | |
73 | * treat the IV as associated data; nevertheless the length passed to | |
74 | * aead_request_set_ad() must include it. | |
5d1d65f8 HX |
75 | */ |
76 | ||
b0d955ba | 77 | struct crypto_aead; |
244d22ff | 78 | struct scatterlist; |
b0d955ba | 79 | |
5d1d65f8 HX |
80 | /** |
81 | * struct aead_request - AEAD request | |
82 | * @base: Common attributes for async crypto requests | |
83 | * @assoclen: Length in bytes of associated data for authentication | |
84 | * @cryptlen: Length of data to be encrypted or decrypted | |
85 | * @iv: Initialisation vector | |
5d1d65f8 HX |
86 | * @src: Source data |
87 | * @dst: Destination data | |
88 | * @__ctx: Start of private context data | |
89 | */ | |
90 | struct aead_request { | |
91 | struct crypto_async_request base; | |
92 | ||
93 | unsigned int assoclen; | |
94 | unsigned int cryptlen; | |
95 | ||
96 | u8 *iv; | |
97 | ||
5d1d65f8 HX |
98 | struct scatterlist *src; |
99 | struct scatterlist *dst; | |
100 | ||
101 | void *__ctx[] CRYPTO_MINALIGN_ATTR; | |
102 | }; | |
103 | ||
0df4adf8 HX |
104 | /* |
105 | * struct crypto_istat_aead - statistics for AEAD algorithm | |
106 | * @encrypt_cnt: number of encrypt requests | |
107 | * @encrypt_tlen: total data size handled by encrypt requests | |
108 | * @decrypt_cnt: number of decrypt requests | |
109 | * @decrypt_tlen: total data size handled by decrypt requests | |
110 | * @err_cnt: number of error for AEAD requests | |
111 | */ | |
112 | struct crypto_istat_aead { | |
113 | atomic64_t encrypt_cnt; | |
114 | atomic64_t encrypt_tlen; | |
115 | atomic64_t decrypt_cnt; | |
116 | atomic64_t decrypt_tlen; | |
117 | atomic64_t err_cnt; | |
118 | }; | |
119 | ||
63293c61 HX |
120 | /** |
121 | * struct aead_alg - AEAD cipher definition | |
122 | * @maxauthsize: Set the maximum authentication tag size supported by the | |
123 | * transformation. A transformation may support smaller tag sizes. | |
124 | * As the authentication tag is a message digest to ensure the | |
125 | * integrity of the encrypted data, a consumer typically wants the | |
126 | * largest authentication tag possible as defined by this | |
127 | * variable. | |
128 | * @setauthsize: Set authentication size for the AEAD transformation. This | |
129 | * function is used to specify the consumer requested size of the | |
130 | * authentication tag to be either generated by the transformation | |
131 | * during encryption or the size of the authentication tag to be | |
132 | * supplied during the decryption operation. This function is also | |
133 | * responsible for checking the authentication tag size for | |
134 | * validity. | |
7a530aa9 HX |
135 | * @setkey: see struct skcipher_alg |
136 | * @encrypt: see struct skcipher_alg | |
137 | * @decrypt: see struct skcipher_alg | |
0df4adf8 | 138 | * @stat: statistics for AEAD algorithm |
7a530aa9 HX |
139 | * @ivsize: see struct skcipher_alg |
140 | * @chunksize: see struct skcipher_alg | |
5eb8ec6d HX |
141 | * @init: Initialize the cryptographic transformation object. This function |
142 | * is used to initialize the cryptographic transformation object. | |
143 | * This function is called only once at the instantiation time, right | |
144 | * after the transformation context was allocated. In case the | |
145 | * cryptographic hardware has some special requirements which need to | |
146 | * be handled by software, this function shall check for the precise | |
147 | * requirement of the transformation and put any software fallbacks | |
148 | * in place. | |
149 | * @exit: Deinitialize the cryptographic transformation object. This is a | |
150 | * counterpart to @init, used to remove various changes set in | |
151 | * @init. | |
70e088fe | 152 | * @base: Definition of a generic crypto cipher algorithm. |
63293c61 HX |
153 | * |
154 | * All fields except @ivsize is mandatory and must be filled. | |
155 | */ | |
156 | struct aead_alg { | |
157 | int (*setkey)(struct crypto_aead *tfm, const u8 *key, | |
158 | unsigned int keylen); | |
159 | int (*setauthsize)(struct crypto_aead *tfm, unsigned int authsize); | |
160 | int (*encrypt)(struct aead_request *req); | |
161 | int (*decrypt)(struct aead_request *req); | |
5eb8ec6d HX |
162 | int (*init)(struct crypto_aead *tfm); |
163 | void (*exit)(struct crypto_aead *tfm); | |
63293c61 | 164 | |
0df4adf8 HX |
165 | #ifdef CONFIG_CRYPTO_STATS |
166 | struct crypto_istat_aead stat; | |
167 | #endif | |
168 | ||
63293c61 HX |
169 | unsigned int ivsize; |
170 | unsigned int maxauthsize; | |
7a530aa9 | 171 | unsigned int chunksize; |
63293c61 HX |
172 | |
173 | struct crypto_alg base; | |
174 | }; | |
175 | ||
5d1d65f8 | 176 | struct crypto_aead { |
5d1d65f8 HX |
177 | unsigned int authsize; |
178 | unsigned int reqsize; | |
179 | ||
180 | struct crypto_tfm base; | |
181 | }; | |
182 | ||
183 | static inline struct crypto_aead *__crypto_aead_cast(struct crypto_tfm *tfm) | |
184 | { | |
185 | return container_of(tfm, struct crypto_aead, base); | |
186 | } | |
187 | ||
188 | /** | |
189 | * crypto_alloc_aead() - allocate AEAD cipher handle | |
190 | * @alg_name: is the cra_name / name or cra_driver_name / driver name of the | |
191 | * AEAD cipher | |
192 | * @type: specifies the type of the cipher | |
193 | * @mask: specifies the mask for the cipher | |
194 | * | |
195 | * Allocate a cipher handle for an AEAD. The returned struct | |
196 | * crypto_aead is the cipher handle that is required for any subsequent | |
197 | * API invocation for that AEAD. | |
198 | * | |
199 | * Return: allocated cipher handle in case of success; IS_ERR() is true in case | |
200 | * of an error, PTR_ERR() returns the error code. | |
201 | */ | |
202 | struct crypto_aead *crypto_alloc_aead(const char *alg_name, u32 type, u32 mask); | |
203 | ||
204 | static inline struct crypto_tfm *crypto_aead_tfm(struct crypto_aead *tfm) | |
205 | { | |
206 | return &tfm->base; | |
207 | } | |
208 | ||
209 | /** | |
210 | * crypto_free_aead() - zeroize and free aead handle | |
211 | * @tfm: cipher handle to be freed | |
83681f2b AB |
212 | * |
213 | * If @tfm is a NULL or error pointer, this function does nothing. | |
5d1d65f8 HX |
214 | */ |
215 | static inline void crypto_free_aead(struct crypto_aead *tfm) | |
216 | { | |
217 | crypto_destroy_tfm(tfm, crypto_aead_tfm(tfm)); | |
218 | } | |
219 | ||
da094e0f EB |
220 | static inline const char *crypto_aead_driver_name(struct crypto_aead *tfm) |
221 | { | |
222 | return crypto_tfm_alg_driver_name(crypto_aead_tfm(tfm)); | |
223 | } | |
224 | ||
30e4c010 HX |
225 | static inline struct aead_alg *crypto_aead_alg(struct crypto_aead *tfm) |
226 | { | |
227 | return container_of(crypto_aead_tfm(tfm)->__crt_alg, | |
228 | struct aead_alg, base); | |
229 | } | |
230 | ||
231 | static inline unsigned int crypto_aead_alg_ivsize(struct aead_alg *alg) | |
232 | { | |
b0d955ba | 233 | return alg->ivsize; |
30e4c010 HX |
234 | } |
235 | ||
5d1d65f8 HX |
236 | /** |
237 | * crypto_aead_ivsize() - obtain IV size | |
238 | * @tfm: cipher handle | |
239 | * | |
240 | * The size of the IV for the aead referenced by the cipher handle is | |
241 | * returned. This IV size may be zero if the cipher does not need an IV. | |
242 | * | |
243 | * Return: IV size in bytes | |
244 | */ | |
245 | static inline unsigned int crypto_aead_ivsize(struct crypto_aead *tfm) | |
246 | { | |
30e4c010 | 247 | return crypto_aead_alg_ivsize(crypto_aead_alg(tfm)); |
5d1d65f8 HX |
248 | } |
249 | ||
250 | /** | |
251 | * crypto_aead_authsize() - obtain maximum authentication data size | |
252 | * @tfm: cipher handle | |
253 | * | |
254 | * The maximum size of the authentication data for the AEAD cipher referenced | |
255 | * by the AEAD cipher handle is returned. The authentication data size may be | |
256 | * zero if the cipher implements a hard-coded maximum. | |
257 | * | |
258 | * The authentication data may also be known as "tag value". | |
259 | * | |
260 | * Return: authentication data size / tag size in bytes | |
261 | */ | |
262 | static inline unsigned int crypto_aead_authsize(struct crypto_aead *tfm) | |
263 | { | |
264 | return tfm->authsize; | |
265 | } | |
266 | ||
095be695 EB |
267 | static inline unsigned int crypto_aead_alg_maxauthsize(struct aead_alg *alg) |
268 | { | |
269 | return alg->maxauthsize; | |
270 | } | |
271 | ||
272 | static inline unsigned int crypto_aead_maxauthsize(struct crypto_aead *aead) | |
273 | { | |
274 | return crypto_aead_alg_maxauthsize(crypto_aead_alg(aead)); | |
275 | } | |
276 | ||
5d1d65f8 HX |
277 | /** |
278 | * crypto_aead_blocksize() - obtain block size of cipher | |
279 | * @tfm: cipher handle | |
280 | * | |
281 | * The block size for the AEAD referenced with the cipher handle is returned. | |
282 | * The caller may use that information to allocate appropriate memory for the | |
283 | * data returned by the encryption or decryption operation | |
284 | * | |
285 | * Return: block size of cipher | |
286 | */ | |
287 | static inline unsigned int crypto_aead_blocksize(struct crypto_aead *tfm) | |
288 | { | |
289 | return crypto_tfm_alg_blocksize(crypto_aead_tfm(tfm)); | |
290 | } | |
291 | ||
292 | static inline unsigned int crypto_aead_alignmask(struct crypto_aead *tfm) | |
293 | { | |
294 | return crypto_tfm_alg_alignmask(crypto_aead_tfm(tfm)); | |
295 | } | |
296 | ||
297 | static inline u32 crypto_aead_get_flags(struct crypto_aead *tfm) | |
298 | { | |
299 | return crypto_tfm_get_flags(crypto_aead_tfm(tfm)); | |
300 | } | |
301 | ||
302 | static inline void crypto_aead_set_flags(struct crypto_aead *tfm, u32 flags) | |
303 | { | |
304 | crypto_tfm_set_flags(crypto_aead_tfm(tfm), flags); | |
305 | } | |
306 | ||
307 | static inline void crypto_aead_clear_flags(struct crypto_aead *tfm, u32 flags) | |
308 | { | |
309 | crypto_tfm_clear_flags(crypto_aead_tfm(tfm), flags); | |
310 | } | |
311 | ||
312 | /** | |
313 | * crypto_aead_setkey() - set key for cipher | |
314 | * @tfm: cipher handle | |
315 | * @key: buffer holding the key | |
316 | * @keylen: length of the key in bytes | |
317 | * | |
318 | * The caller provided key is set for the AEAD referenced by the cipher | |
319 | * handle. | |
320 | * | |
321 | * Note, the key length determines the cipher type. Many block ciphers implement | |
322 | * different cipher modes depending on the key size, such as AES-128 vs AES-192 | |
323 | * vs. AES-256. When providing a 16 byte key for an AES cipher handle, AES-128 | |
324 | * is performed. | |
325 | * | |
326 | * Return: 0 if the setting of the key was successful; < 0 if an error occurred | |
327 | */ | |
328 | int crypto_aead_setkey(struct crypto_aead *tfm, | |
329 | const u8 *key, unsigned int keylen); | |
330 | ||
331 | /** | |
332 | * crypto_aead_setauthsize() - set authentication data size | |
333 | * @tfm: cipher handle | |
334 | * @authsize: size of the authentication data / tag in bytes | |
335 | * | |
336 | * Set the authentication data size / tag size. AEAD requires an authentication | |
337 | * tag (or MAC) in addition to the associated data. | |
338 | * | |
339 | * Return: 0 if the setting of the key was successful; < 0 if an error occurred | |
340 | */ | |
341 | int crypto_aead_setauthsize(struct crypto_aead *tfm, unsigned int authsize); | |
342 | ||
343 | static inline struct crypto_aead *crypto_aead_reqtfm(struct aead_request *req) | |
344 | { | |
345 | return __crypto_aead_cast(req->base.tfm); | |
346 | } | |
347 | ||
348 | /** | |
349 | * crypto_aead_encrypt() - encrypt plaintext | |
350 | * @req: reference to the aead_request handle that holds all information | |
351 | * needed to perform the cipher operation | |
352 | * | |
353 | * Encrypt plaintext data using the aead_request handle. That data structure | |
354 | * and how it is filled with data is discussed with the aead_request_* | |
355 | * functions. | |
356 | * | |
357 | * IMPORTANT NOTE The encryption operation creates the authentication data / | |
358 | * tag. That data is concatenated with the created ciphertext. | |
359 | * The ciphertext memory size is therefore the given number of | |
360 | * block cipher blocks + the size defined by the | |
361 | * crypto_aead_setauthsize invocation. The caller must ensure | |
362 | * that sufficient memory is available for the ciphertext and | |
363 | * the authentication tag. | |
364 | * | |
365 | * Return: 0 if the cipher operation was successful; < 0 if an error occurred | |
366 | */ | |
f2fe1154 | 367 | int crypto_aead_encrypt(struct aead_request *req); |
5d1d65f8 HX |
368 | |
369 | /** | |
370 | * crypto_aead_decrypt() - decrypt ciphertext | |
d63007eb | 371 | * @req: reference to the aead_request handle that holds all information |
5d1d65f8 HX |
372 | * needed to perform the cipher operation |
373 | * | |
374 | * Decrypt ciphertext data using the aead_request handle. That data structure | |
375 | * and how it is filled with data is discussed with the aead_request_* | |
376 | * functions. | |
377 | * | |
378 | * IMPORTANT NOTE The caller must concatenate the ciphertext followed by the | |
379 | * authentication data / tag. That authentication data / tag | |
380 | * must have the size defined by the crypto_aead_setauthsize | |
381 | * invocation. | |
382 | * | |
383 | * | |
384 | * Return: 0 if the cipher operation was successful; -EBADMSG: The AEAD | |
385 | * cipher operation performs the authentication of the data during the | |
386 | * decryption operation. Therefore, the function returns this error if | |
387 | * the authentication of the ciphertext was unsuccessful (i.e. the | |
388 | * integrity of the ciphertext or the associated data was violated); | |
389 | * < 0 if an error occurred. | |
390 | */ | |
f2fe1154 | 391 | int crypto_aead_decrypt(struct aead_request *req); |
5d1d65f8 HX |
392 | |
393 | /** | |
394 | * DOC: Asynchronous AEAD Request Handle | |
395 | * | |
396 | * The aead_request data structure contains all pointers to data required for | |
397 | * the AEAD cipher operation. This includes the cipher handle (which can be | |
398 | * used by multiple aead_request instances), pointer to plaintext and | |
399 | * ciphertext, asynchronous callback function, etc. It acts as a handle to the | |
400 | * aead_request_* API calls in a similar way as AEAD handle to the | |
401 | * crypto_aead_* API calls. | |
402 | */ | |
403 | ||
404 | /** | |
405 | * crypto_aead_reqsize() - obtain size of the request data structure | |
406 | * @tfm: cipher handle | |
407 | * | |
408 | * Return: number of bytes | |
409 | */ | |
b0d955ba HX |
410 | static inline unsigned int crypto_aead_reqsize(struct crypto_aead *tfm) |
411 | { | |
412 | return tfm->reqsize; | |
413 | } | |
5d1d65f8 HX |
414 | |
415 | /** | |
416 | * aead_request_set_tfm() - update cipher handle reference in request | |
417 | * @req: request handle to be modified | |
418 | * @tfm: cipher handle that shall be added to the request handle | |
419 | * | |
420 | * Allow the caller to replace the existing aead handle in the request | |
421 | * data structure with a different one. | |
422 | */ | |
423 | static inline void aead_request_set_tfm(struct aead_request *req, | |
424 | struct crypto_aead *tfm) | |
425 | { | |
b0d955ba | 426 | req->base.tfm = crypto_aead_tfm(tfm); |
5d1d65f8 HX |
427 | } |
428 | ||
429 | /** | |
430 | * aead_request_alloc() - allocate request data structure | |
431 | * @tfm: cipher handle to be registered with the request | |
432 | * @gfp: memory allocation flag that is handed to kmalloc by the API call. | |
433 | * | |
434 | * Allocate the request data structure that must be used with the AEAD | |
435 | * encrypt and decrypt API calls. During the allocation, the provided aead | |
436 | * handle is registered in the request data structure. | |
437 | * | |
6eae29e7 | 438 | * Return: allocated request handle in case of success, or NULL if out of memory |
5d1d65f8 HX |
439 | */ |
440 | static inline struct aead_request *aead_request_alloc(struct crypto_aead *tfm, | |
441 | gfp_t gfp) | |
442 | { | |
443 | struct aead_request *req; | |
444 | ||
445 | req = kmalloc(sizeof(*req) + crypto_aead_reqsize(tfm), gfp); | |
446 | ||
447 | if (likely(req)) | |
448 | aead_request_set_tfm(req, tfm); | |
449 | ||
450 | return req; | |
451 | } | |
452 | ||
453 | /** | |
454 | * aead_request_free() - zeroize and free request data structure | |
455 | * @req: request data structure cipher handle to be freed | |
456 | */ | |
457 | static inline void aead_request_free(struct aead_request *req) | |
458 | { | |
453431a5 | 459 | kfree_sensitive(req); |
5d1d65f8 HX |
460 | } |
461 | ||
462 | /** | |
463 | * aead_request_set_callback() - set asynchronous callback function | |
464 | * @req: request handle | |
465 | * @flags: specify zero or an ORing of the flags | |
466 | * CRYPTO_TFM_REQ_MAY_BACKLOG the request queue may back log and | |
467 | * increase the wait queue beyond the initial maximum size; | |
468 | * CRYPTO_TFM_REQ_MAY_SLEEP the request processing may sleep | |
469 | * @compl: callback function pointer to be registered with the request handle | |
470 | * @data: The data pointer refers to memory that is not used by the kernel | |
471 | * crypto API, but provided to the callback function for it to use. Here, | |
472 | * the caller can provide a reference to memory the callback function can | |
473 | * operate on. As the callback function is invoked asynchronously to the | |
474 | * related functionality, it may need to access data structures of the | |
475 | * related functionality which can be referenced using this pointer. The | |
476 | * callback function can access the memory via the "data" field in the | |
477 | * crypto_async_request data structure provided to the callback function. | |
478 | * | |
479 | * Setting the callback function that is triggered once the cipher operation | |
480 | * completes | |
481 | * | |
482 | * The callback function is registered with the aead_request handle and | |
0184cfe7 | 483 | * must comply with the following template:: |
5d1d65f8 HX |
484 | * |
485 | * void callback_function(struct crypto_async_request *req, int error) | |
486 | */ | |
487 | static inline void aead_request_set_callback(struct aead_request *req, | |
488 | u32 flags, | |
489 | crypto_completion_t compl, | |
490 | void *data) | |
491 | { | |
492 | req->base.complete = compl; | |
493 | req->base.data = data; | |
494 | req->base.flags = flags; | |
495 | } | |
496 | ||
497 | /** | |
498 | * aead_request_set_crypt - set data buffers | |
499 | * @req: request handle | |
500 | * @src: source scatter / gather list | |
501 | * @dst: destination scatter / gather list | |
502 | * @cryptlen: number of bytes to process from @src | |
503 | * @iv: IV for the cipher operation which must comply with the IV size defined | |
504 | * by crypto_aead_ivsize() | |
505 | * | |
addfda2f SM |
506 | * Setting the source data and destination data scatter / gather lists which |
507 | * hold the associated data concatenated with the plaintext or ciphertext. See | |
508 | * below for the authentication tag. | |
5d1d65f8 HX |
509 | * |
510 | * For encryption, the source is treated as the plaintext and the | |
511 | * destination is the ciphertext. For a decryption operation, the use is | |
512 | * reversed - the source is the ciphertext and the destination is the plaintext. | |
513 | * | |
3f692d5f SM |
514 | * The memory structure for cipher operation has the following structure: |
515 | * | |
516 | * - AEAD encryption input: assoc data || plaintext | |
155f7d32 | 517 | * - AEAD encryption output: assoc data || ciphertext || auth tag |
3f692d5f SM |
518 | * - AEAD decryption input: assoc data || ciphertext || auth tag |
519 | * - AEAD decryption output: assoc data || plaintext | |
520 | * | |
521 | * Albeit the kernel requires the presence of the AAD buffer, however, | |
522 | * the kernel does not fill the AAD buffer in the output case. If the | |
523 | * caller wants to have that data buffer filled, the caller must either | |
524 | * use an in-place cipher operation (i.e. same memory location for | |
525 | * input/output memory location). | |
5d1d65f8 HX |
526 | */ |
527 | static inline void aead_request_set_crypt(struct aead_request *req, | |
528 | struct scatterlist *src, | |
529 | struct scatterlist *dst, | |
530 | unsigned int cryptlen, u8 *iv) | |
531 | { | |
532 | req->src = src; | |
533 | req->dst = dst; | |
534 | req->cryptlen = cryptlen; | |
535 | req->iv = iv; | |
536 | } | |
537 | ||
996d98d8 HX |
538 | /** |
539 | * aead_request_set_ad - set associated data information | |
540 | * @req: request handle | |
541 | * @assoclen: number of bytes in associated data | |
996d98d8 HX |
542 | * |
543 | * Setting the AD information. This function sets the length of | |
693b549d | 544 | * the associated data. |
996d98d8 HX |
545 | */ |
546 | static inline void aead_request_set_ad(struct aead_request *req, | |
374d4ad1 | 547 | unsigned int assoclen) |
996d98d8 HX |
548 | { |
549 | req->assoclen = assoclen; | |
3a282bd2 HX |
550 | } |
551 | ||
743edf57 | 552 | #endif /* _CRYPTO_AEAD_H */ |