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743edf57 HX |
1 | /* |
2 | * AEAD: Authenticated Encryption with Associated Data | |
3 | * | |
b0d955ba | 4 | * Copyright (c) 2007-2015 Herbert Xu <herbert@gondor.apana.org.au> |
743edf57 HX |
5 | * |
6 | * This program is free software; you can redistribute it and/or modify it | |
7 | * under the terms of the GNU General Public License as published by the Free | |
8 | * Software Foundation; either version 2 of the License, or (at your option) | |
9 | * any later version. | |
10 | * | |
11 | */ | |
12 | ||
13 | #ifndef _CRYPTO_AEAD_H | |
14 | #define _CRYPTO_AEAD_H | |
15 | ||
16 | #include <linux/crypto.h> | |
17 | #include <linux/kernel.h> | |
3a282bd2 | 18 | #include <linux/slab.h> |
743edf57 | 19 | |
5d1d65f8 HX |
20 | /** |
21 | * DOC: Authenticated Encryption With Associated Data (AEAD) Cipher API | |
22 | * | |
23 | * The AEAD cipher API is used with the ciphers of type CRYPTO_ALG_TYPE_AEAD | |
24 | * (listed as type "aead" in /proc/crypto) | |
25 | * | |
26 | * The most prominent examples for this type of encryption is GCM and CCM. | |
27 | * However, the kernel supports other types of AEAD ciphers which are defined | |
28 | * with the following cipher string: | |
29 | * | |
30 | * authenc(keyed message digest, block cipher) | |
31 | * | |
32 | * For example: authenc(hmac(sha256), cbc(aes)) | |
33 | * | |
3981d37f SM |
34 | * The example code provided for the symmetric key cipher operation |
35 | * applies here as well. Naturally all *skcipher* symbols must be exchanged | |
12f7c14a | 36 | * the *aead* pendants discussed in the following. In addition, for the AEAD |
3981d37f | 37 | * operation, the aead_request_set_ad function must be used to set the |
5d1d65f8 HX |
38 | * pointer to the associated data memory location before performing the |
39 | * encryption or decryption operation. In case of an encryption, the associated | |
40 | * data memory is filled during the encryption operation. For decryption, the | |
41 | * associated data memory must contain data that is used to verify the integrity | |
42 | * of the decrypted data. Another deviation from the asynchronous block cipher | |
43 | * operation is that the caller should explicitly check for -EBADMSG of the | |
44 | * crypto_aead_decrypt. That error indicates an authentication error, i.e. | |
45 | * a breach in the integrity of the message. In essence, that -EBADMSG error | |
46 | * code is the key bonus an AEAD cipher has over "standard" block chaining | |
47 | * modes. | |
f6e45c24 SM |
48 | * |
49 | * Memory Structure: | |
50 | * | |
51 | * To support the needs of the most prominent user of AEAD ciphers, namely | |
52 | * IPSEC, the AEAD ciphers have a special memory layout the caller must adhere | |
53 | * to. | |
54 | * | |
55 | * The scatter list pointing to the input data must contain: | |
56 | * | |
57 | * * for RFC4106 ciphers, the concatenation of | |
0184cfe7 SM |
58 | * associated authentication data || IV || plaintext or ciphertext. Note, the |
59 | * same IV (buffer) is also set with the aead_request_set_crypt call. Note, | |
60 | * the API call of aead_request_set_ad must provide the length of the AAD and | |
61 | * the IV. The API call of aead_request_set_crypt only points to the size of | |
62 | * the input plaintext or ciphertext. | |
f6e45c24 SM |
63 | * |
64 | * * for "normal" AEAD ciphers, the concatenation of | |
0184cfe7 | 65 | * associated authentication data || plaintext or ciphertext. |
f6e45c24 SM |
66 | * |
67 | * It is important to note that if multiple scatter gather list entries form | |
68 | * the input data mentioned above, the first entry must not point to a NULL | |
69 | * buffer. If there is any potential where the AAD buffer can be NULL, the | |
70 | * calling code must contain a precaution to ensure that this does not result | |
71 | * in the first scatter gather list entry pointing to a NULL buffer. | |
5d1d65f8 HX |
72 | */ |
73 | ||
b0d955ba HX |
74 | struct crypto_aead; |
75 | ||
5d1d65f8 HX |
76 | /** |
77 | * struct aead_request - AEAD request | |
78 | * @base: Common attributes for async crypto requests | |
79 | * @assoclen: Length in bytes of associated data for authentication | |
80 | * @cryptlen: Length of data to be encrypted or decrypted | |
81 | * @iv: Initialisation vector | |
5d1d65f8 HX |
82 | * @src: Source data |
83 | * @dst: Destination data | |
84 | * @__ctx: Start of private context data | |
85 | */ | |
86 | struct aead_request { | |
87 | struct crypto_async_request base; | |
88 | ||
89 | unsigned int assoclen; | |
90 | unsigned int cryptlen; | |
91 | ||
92 | u8 *iv; | |
93 | ||
5d1d65f8 HX |
94 | struct scatterlist *src; |
95 | struct scatterlist *dst; | |
96 | ||
97 | void *__ctx[] CRYPTO_MINALIGN_ATTR; | |
98 | }; | |
99 | ||
63293c61 HX |
100 | /** |
101 | * struct aead_alg - AEAD cipher definition | |
102 | * @maxauthsize: Set the maximum authentication tag size supported by the | |
103 | * transformation. A transformation may support smaller tag sizes. | |
104 | * As the authentication tag is a message digest to ensure the | |
105 | * integrity of the encrypted data, a consumer typically wants the | |
106 | * largest authentication tag possible as defined by this | |
107 | * variable. | |
108 | * @setauthsize: Set authentication size for the AEAD transformation. This | |
109 | * function is used to specify the consumer requested size of the | |
110 | * authentication tag to be either generated by the transformation | |
111 | * during encryption or the size of the authentication tag to be | |
112 | * supplied during the decryption operation. This function is also | |
113 | * responsible for checking the authentication tag size for | |
114 | * validity. | |
7a530aa9 HX |
115 | * @setkey: see struct skcipher_alg |
116 | * @encrypt: see struct skcipher_alg | |
117 | * @decrypt: see struct skcipher_alg | |
118 | * @geniv: see struct skcipher_alg | |
119 | * @ivsize: see struct skcipher_alg | |
120 | * @chunksize: see struct skcipher_alg | |
5eb8ec6d HX |
121 | * @init: Initialize the cryptographic transformation object. This function |
122 | * is used to initialize the cryptographic transformation object. | |
123 | * This function is called only once at the instantiation time, right | |
124 | * after the transformation context was allocated. In case the | |
125 | * cryptographic hardware has some special requirements which need to | |
126 | * be handled by software, this function shall check for the precise | |
127 | * requirement of the transformation and put any software fallbacks | |
128 | * in place. | |
129 | * @exit: Deinitialize the cryptographic transformation object. This is a | |
130 | * counterpart to @init, used to remove various changes set in | |
131 | * @init. | |
70e088fe | 132 | * @base: Definition of a generic crypto cipher algorithm. |
63293c61 HX |
133 | * |
134 | * All fields except @ivsize is mandatory and must be filled. | |
135 | */ | |
136 | struct aead_alg { | |
137 | int (*setkey)(struct crypto_aead *tfm, const u8 *key, | |
138 | unsigned int keylen); | |
139 | int (*setauthsize)(struct crypto_aead *tfm, unsigned int authsize); | |
140 | int (*encrypt)(struct aead_request *req); | |
141 | int (*decrypt)(struct aead_request *req); | |
5eb8ec6d HX |
142 | int (*init)(struct crypto_aead *tfm); |
143 | void (*exit)(struct crypto_aead *tfm); | |
63293c61 HX |
144 | |
145 | const char *geniv; | |
146 | ||
147 | unsigned int ivsize; | |
148 | unsigned int maxauthsize; | |
7a530aa9 | 149 | unsigned int chunksize; |
63293c61 HX |
150 | |
151 | struct crypto_alg base; | |
152 | }; | |
153 | ||
5d1d65f8 | 154 | struct crypto_aead { |
5d1d65f8 HX |
155 | unsigned int authsize; |
156 | unsigned int reqsize; | |
157 | ||
158 | struct crypto_tfm base; | |
159 | }; | |
160 | ||
161 | static inline struct crypto_aead *__crypto_aead_cast(struct crypto_tfm *tfm) | |
162 | { | |
163 | return container_of(tfm, struct crypto_aead, base); | |
164 | } | |
165 | ||
166 | /** | |
167 | * crypto_alloc_aead() - allocate AEAD cipher handle | |
168 | * @alg_name: is the cra_name / name or cra_driver_name / driver name of the | |
169 | * AEAD cipher | |
170 | * @type: specifies the type of the cipher | |
171 | * @mask: specifies the mask for the cipher | |
172 | * | |
173 | * Allocate a cipher handle for an AEAD. The returned struct | |
174 | * crypto_aead is the cipher handle that is required for any subsequent | |
175 | * API invocation for that AEAD. | |
176 | * | |
177 | * Return: allocated cipher handle in case of success; IS_ERR() is true in case | |
178 | * of an error, PTR_ERR() returns the error code. | |
179 | */ | |
180 | struct crypto_aead *crypto_alloc_aead(const char *alg_name, u32 type, u32 mask); | |
181 | ||
182 | static inline struct crypto_tfm *crypto_aead_tfm(struct crypto_aead *tfm) | |
183 | { | |
184 | return &tfm->base; | |
185 | } | |
186 | ||
187 | /** | |
188 | * crypto_free_aead() - zeroize and free aead handle | |
189 | * @tfm: cipher handle to be freed | |
190 | */ | |
191 | static inline void crypto_free_aead(struct crypto_aead *tfm) | |
192 | { | |
193 | crypto_destroy_tfm(tfm, crypto_aead_tfm(tfm)); | |
194 | } | |
195 | ||
30e4c010 HX |
196 | static inline struct aead_alg *crypto_aead_alg(struct crypto_aead *tfm) |
197 | { | |
198 | return container_of(crypto_aead_tfm(tfm)->__crt_alg, | |
199 | struct aead_alg, base); | |
200 | } | |
201 | ||
202 | static inline unsigned int crypto_aead_alg_ivsize(struct aead_alg *alg) | |
203 | { | |
b0d955ba | 204 | return alg->ivsize; |
30e4c010 HX |
205 | } |
206 | ||
5d1d65f8 HX |
207 | /** |
208 | * crypto_aead_ivsize() - obtain IV size | |
209 | * @tfm: cipher handle | |
210 | * | |
211 | * The size of the IV for the aead referenced by the cipher handle is | |
212 | * returned. This IV size may be zero if the cipher does not need an IV. | |
213 | * | |
214 | * Return: IV size in bytes | |
215 | */ | |
216 | static inline unsigned int crypto_aead_ivsize(struct crypto_aead *tfm) | |
217 | { | |
30e4c010 | 218 | return crypto_aead_alg_ivsize(crypto_aead_alg(tfm)); |
5d1d65f8 HX |
219 | } |
220 | ||
221 | /** | |
222 | * crypto_aead_authsize() - obtain maximum authentication data size | |
223 | * @tfm: cipher handle | |
224 | * | |
225 | * The maximum size of the authentication data for the AEAD cipher referenced | |
226 | * by the AEAD cipher handle is returned. The authentication data size may be | |
227 | * zero if the cipher implements a hard-coded maximum. | |
228 | * | |
229 | * The authentication data may also be known as "tag value". | |
230 | * | |
231 | * Return: authentication data size / tag size in bytes | |
232 | */ | |
233 | static inline unsigned int crypto_aead_authsize(struct crypto_aead *tfm) | |
234 | { | |
235 | return tfm->authsize; | |
236 | } | |
237 | ||
238 | /** | |
239 | * crypto_aead_blocksize() - obtain block size of cipher | |
240 | * @tfm: cipher handle | |
241 | * | |
242 | * The block size for the AEAD referenced with the cipher handle is returned. | |
243 | * The caller may use that information to allocate appropriate memory for the | |
244 | * data returned by the encryption or decryption operation | |
245 | * | |
246 | * Return: block size of cipher | |
247 | */ | |
248 | static inline unsigned int crypto_aead_blocksize(struct crypto_aead *tfm) | |
249 | { | |
250 | return crypto_tfm_alg_blocksize(crypto_aead_tfm(tfm)); | |
251 | } | |
252 | ||
253 | static inline unsigned int crypto_aead_alignmask(struct crypto_aead *tfm) | |
254 | { | |
255 | return crypto_tfm_alg_alignmask(crypto_aead_tfm(tfm)); | |
256 | } | |
257 | ||
258 | static inline u32 crypto_aead_get_flags(struct crypto_aead *tfm) | |
259 | { | |
260 | return crypto_tfm_get_flags(crypto_aead_tfm(tfm)); | |
261 | } | |
262 | ||
263 | static inline void crypto_aead_set_flags(struct crypto_aead *tfm, u32 flags) | |
264 | { | |
265 | crypto_tfm_set_flags(crypto_aead_tfm(tfm), flags); | |
266 | } | |
267 | ||
268 | static inline void crypto_aead_clear_flags(struct crypto_aead *tfm, u32 flags) | |
269 | { | |
270 | crypto_tfm_clear_flags(crypto_aead_tfm(tfm), flags); | |
271 | } | |
272 | ||
273 | /** | |
274 | * crypto_aead_setkey() - set key for cipher | |
275 | * @tfm: cipher handle | |
276 | * @key: buffer holding the key | |
277 | * @keylen: length of the key in bytes | |
278 | * | |
279 | * The caller provided key is set for the AEAD referenced by the cipher | |
280 | * handle. | |
281 | * | |
282 | * Note, the key length determines the cipher type. Many block ciphers implement | |
283 | * different cipher modes depending on the key size, such as AES-128 vs AES-192 | |
284 | * vs. AES-256. When providing a 16 byte key for an AES cipher handle, AES-128 | |
285 | * is performed. | |
286 | * | |
287 | * Return: 0 if the setting of the key was successful; < 0 if an error occurred | |
288 | */ | |
289 | int crypto_aead_setkey(struct crypto_aead *tfm, | |
290 | const u8 *key, unsigned int keylen); | |
291 | ||
292 | /** | |
293 | * crypto_aead_setauthsize() - set authentication data size | |
294 | * @tfm: cipher handle | |
295 | * @authsize: size of the authentication data / tag in bytes | |
296 | * | |
297 | * Set the authentication data size / tag size. AEAD requires an authentication | |
298 | * tag (or MAC) in addition to the associated data. | |
299 | * | |
300 | * Return: 0 if the setting of the key was successful; < 0 if an error occurred | |
301 | */ | |
302 | int crypto_aead_setauthsize(struct crypto_aead *tfm, unsigned int authsize); | |
303 | ||
304 | static inline struct crypto_aead *crypto_aead_reqtfm(struct aead_request *req) | |
305 | { | |
306 | return __crypto_aead_cast(req->base.tfm); | |
307 | } | |
308 | ||
cac5818c CL |
309 | static inline void crypto_stat_aead_encrypt(struct aead_request *req, int ret) |
310 | { | |
311 | #ifdef CONFIG_CRYPTO_STATS | |
312 | struct crypto_aead *tfm = crypto_aead_reqtfm(req); | |
313 | ||
314 | if (ret && ret != -EINPROGRESS && ret != -EBUSY) { | |
315 | atomic_inc(&tfm->base.__crt_alg->aead_err_cnt); | |
316 | } else { | |
317 | atomic_inc(&tfm->base.__crt_alg->encrypt_cnt); | |
318 | atomic64_add(req->cryptlen, &tfm->base.__crt_alg->encrypt_tlen); | |
319 | } | |
320 | #endif | |
321 | } | |
322 | ||
323 | static inline void crypto_stat_aead_decrypt(struct aead_request *req, int ret) | |
324 | { | |
325 | #ifdef CONFIG_CRYPTO_STATS | |
326 | struct crypto_aead *tfm = crypto_aead_reqtfm(req); | |
327 | ||
328 | if (ret && ret != -EINPROGRESS && ret != -EBUSY) { | |
329 | atomic_inc(&tfm->base.__crt_alg->aead_err_cnt); | |
330 | } else { | |
331 | atomic_inc(&tfm->base.__crt_alg->decrypt_cnt); | |
332 | atomic64_add(req->cryptlen, &tfm->base.__crt_alg->decrypt_tlen); | |
333 | } | |
334 | #endif | |
335 | } | |
336 | ||
5d1d65f8 HX |
337 | /** |
338 | * crypto_aead_encrypt() - encrypt plaintext | |
339 | * @req: reference to the aead_request handle that holds all information | |
340 | * needed to perform the cipher operation | |
341 | * | |
342 | * Encrypt plaintext data using the aead_request handle. That data structure | |
343 | * and how it is filled with data is discussed with the aead_request_* | |
344 | * functions. | |
345 | * | |
346 | * IMPORTANT NOTE The encryption operation creates the authentication data / | |
347 | * tag. That data is concatenated with the created ciphertext. | |
348 | * The ciphertext memory size is therefore the given number of | |
349 | * block cipher blocks + the size defined by the | |
350 | * crypto_aead_setauthsize invocation. The caller must ensure | |
351 | * that sufficient memory is available for the ciphertext and | |
352 | * the authentication tag. | |
353 | * | |
354 | * Return: 0 if the cipher operation was successful; < 0 if an error occurred | |
355 | */ | |
356 | static inline int crypto_aead_encrypt(struct aead_request *req) | |
357 | { | |
dc26c17f | 358 | struct crypto_aead *aead = crypto_aead_reqtfm(req); |
cac5818c | 359 | int ret; |
dc26c17f EB |
360 | |
361 | if (crypto_aead_get_flags(aead) & CRYPTO_TFM_NEED_KEY) | |
cac5818c CL |
362 | ret = -ENOKEY; |
363 | else | |
364 | ret = crypto_aead_alg(aead)->encrypt(req); | |
365 | crypto_stat_aead_encrypt(req, ret); | |
366 | return ret; | |
5d1d65f8 HX |
367 | } |
368 | ||
369 | /** | |
370 | * crypto_aead_decrypt() - decrypt ciphertext | |
371 | * @req: reference to the ablkcipher_request handle that holds all information | |
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 | */ | |
391 | static inline int crypto_aead_decrypt(struct aead_request *req) | |
392 | { | |
b0d955ba | 393 | struct crypto_aead *aead = crypto_aead_reqtfm(req); |
cac5818c | 394 | int ret; |
b0d955ba | 395 | |
dc26c17f | 396 | if (crypto_aead_get_flags(aead) & CRYPTO_TFM_NEED_KEY) |
cac5818c CL |
397 | ret = -ENOKEY; |
398 | else if (req->cryptlen < crypto_aead_authsize(aead)) | |
399 | ret = -EINVAL; | |
400 | else | |
401 | ret = crypto_aead_alg(aead)->decrypt(req); | |
402 | crypto_stat_aead_decrypt(req, ret); | |
403 | return ret; | |
5d1d65f8 HX |
404 | } |
405 | ||
406 | /** | |
407 | * DOC: Asynchronous AEAD Request Handle | |
408 | * | |
409 | * The aead_request data structure contains all pointers to data required for | |
410 | * the AEAD cipher operation. This includes the cipher handle (which can be | |
411 | * used by multiple aead_request instances), pointer to plaintext and | |
412 | * ciphertext, asynchronous callback function, etc. It acts as a handle to the | |
413 | * aead_request_* API calls in a similar way as AEAD handle to the | |
414 | * crypto_aead_* API calls. | |
415 | */ | |
416 | ||
417 | /** | |
418 | * crypto_aead_reqsize() - obtain size of the request data structure | |
419 | * @tfm: cipher handle | |
420 | * | |
421 | * Return: number of bytes | |
422 | */ | |
b0d955ba HX |
423 | static inline unsigned int crypto_aead_reqsize(struct crypto_aead *tfm) |
424 | { | |
425 | return tfm->reqsize; | |
426 | } | |
5d1d65f8 HX |
427 | |
428 | /** | |
429 | * aead_request_set_tfm() - update cipher handle reference in request | |
430 | * @req: request handle to be modified | |
431 | * @tfm: cipher handle that shall be added to the request handle | |
432 | * | |
433 | * Allow the caller to replace the existing aead handle in the request | |
434 | * data structure with a different one. | |
435 | */ | |
436 | static inline void aead_request_set_tfm(struct aead_request *req, | |
437 | struct crypto_aead *tfm) | |
438 | { | |
b0d955ba | 439 | req->base.tfm = crypto_aead_tfm(tfm); |
5d1d65f8 HX |
440 | } |
441 | ||
442 | /** | |
443 | * aead_request_alloc() - allocate request data structure | |
444 | * @tfm: cipher handle to be registered with the request | |
445 | * @gfp: memory allocation flag that is handed to kmalloc by the API call. | |
446 | * | |
447 | * Allocate the request data structure that must be used with the AEAD | |
448 | * encrypt and decrypt API calls. During the allocation, the provided aead | |
449 | * handle is registered in the request data structure. | |
450 | * | |
6eae29e7 | 451 | * Return: allocated request handle in case of success, or NULL if out of memory |
5d1d65f8 HX |
452 | */ |
453 | static inline struct aead_request *aead_request_alloc(struct crypto_aead *tfm, | |
454 | gfp_t gfp) | |
455 | { | |
456 | struct aead_request *req; | |
457 | ||
458 | req = kmalloc(sizeof(*req) + crypto_aead_reqsize(tfm), gfp); | |
459 | ||
460 | if (likely(req)) | |
461 | aead_request_set_tfm(req, tfm); | |
462 | ||
463 | return req; | |
464 | } | |
465 | ||
466 | /** | |
467 | * aead_request_free() - zeroize and free request data structure | |
468 | * @req: request data structure cipher handle to be freed | |
469 | */ | |
470 | static inline void aead_request_free(struct aead_request *req) | |
471 | { | |
472 | kzfree(req); | |
473 | } | |
474 | ||
475 | /** | |
476 | * aead_request_set_callback() - set asynchronous callback function | |
477 | * @req: request handle | |
478 | * @flags: specify zero or an ORing of the flags | |
479 | * CRYPTO_TFM_REQ_MAY_BACKLOG the request queue may back log and | |
480 | * increase the wait queue beyond the initial maximum size; | |
481 | * CRYPTO_TFM_REQ_MAY_SLEEP the request processing may sleep | |
482 | * @compl: callback function pointer to be registered with the request handle | |
483 | * @data: The data pointer refers to memory that is not used by the kernel | |
484 | * crypto API, but provided to the callback function for it to use. Here, | |
485 | * the caller can provide a reference to memory the callback function can | |
486 | * operate on. As the callback function is invoked asynchronously to the | |
487 | * related functionality, it may need to access data structures of the | |
488 | * related functionality which can be referenced using this pointer. The | |
489 | * callback function can access the memory via the "data" field in the | |
490 | * crypto_async_request data structure provided to the callback function. | |
491 | * | |
492 | * Setting the callback function that is triggered once the cipher operation | |
493 | * completes | |
494 | * | |
495 | * The callback function is registered with the aead_request handle and | |
0184cfe7 | 496 | * must comply with the following template:: |
5d1d65f8 HX |
497 | * |
498 | * void callback_function(struct crypto_async_request *req, int error) | |
499 | */ | |
500 | static inline void aead_request_set_callback(struct aead_request *req, | |
501 | u32 flags, | |
502 | crypto_completion_t compl, | |
503 | void *data) | |
504 | { | |
505 | req->base.complete = compl; | |
506 | req->base.data = data; | |
507 | req->base.flags = flags; | |
508 | } | |
509 | ||
510 | /** | |
511 | * aead_request_set_crypt - set data buffers | |
512 | * @req: request handle | |
513 | * @src: source scatter / gather list | |
514 | * @dst: destination scatter / gather list | |
515 | * @cryptlen: number of bytes to process from @src | |
516 | * @iv: IV for the cipher operation which must comply with the IV size defined | |
517 | * by crypto_aead_ivsize() | |
518 | * | |
addfda2f SM |
519 | * Setting the source data and destination data scatter / gather lists which |
520 | * hold the associated data concatenated with the plaintext or ciphertext. See | |
521 | * below for the authentication tag. | |
5d1d65f8 HX |
522 | * |
523 | * For encryption, the source is treated as the plaintext and the | |
524 | * destination is the ciphertext. For a decryption operation, the use is | |
525 | * reversed - the source is the ciphertext and the destination is the plaintext. | |
526 | * | |
3f692d5f SM |
527 | * The memory structure for cipher operation has the following structure: |
528 | * | |
529 | * - AEAD encryption input: assoc data || plaintext | |
530 | * - AEAD encryption output: assoc data || cipherntext || auth tag | |
531 | * - AEAD decryption input: assoc data || ciphertext || auth tag | |
532 | * - AEAD decryption output: assoc data || plaintext | |
533 | * | |
534 | * Albeit the kernel requires the presence of the AAD buffer, however, | |
535 | * the kernel does not fill the AAD buffer in the output case. If the | |
536 | * caller wants to have that data buffer filled, the caller must either | |
537 | * use an in-place cipher operation (i.e. same memory location for | |
538 | * input/output memory location). | |
5d1d65f8 HX |
539 | */ |
540 | static inline void aead_request_set_crypt(struct aead_request *req, | |
541 | struct scatterlist *src, | |
542 | struct scatterlist *dst, | |
543 | unsigned int cryptlen, u8 *iv) | |
544 | { | |
545 | req->src = src; | |
546 | req->dst = dst; | |
547 | req->cryptlen = cryptlen; | |
548 | req->iv = iv; | |
549 | } | |
550 | ||
996d98d8 HX |
551 | /** |
552 | * aead_request_set_ad - set associated data information | |
553 | * @req: request handle | |
554 | * @assoclen: number of bytes in associated data | |
996d98d8 HX |
555 | * |
556 | * Setting the AD information. This function sets the length of | |
693b549d | 557 | * the associated data. |
996d98d8 HX |
558 | */ |
559 | static inline void aead_request_set_ad(struct aead_request *req, | |
374d4ad1 | 560 | unsigned int assoclen) |
996d98d8 HX |
561 | { |
562 | req->assoclen = assoclen; | |
3a282bd2 HX |
563 | } |
564 | ||
743edf57 | 565 | #endif /* _CRYPTO_AEAD_H */ |