1 /* SPDX-License-Identifier: GPL-2.0-or-later */ 2 /* 3 * Symmetric key ciphers. 4 * 5 * Copyright (c) 2007-2015 Herbert Xu <herbert@gondor.apana.org.au> 6 */ 7 8 #ifndef _CRYPTO_SKCIPHER_H 9 #define _CRYPTO_SKCIPHER_H 10 11 #include <linux/crypto.h> 12 #include <linux/kernel.h> 13 #include <linux/slab.h> 14 15 /** 16 * struct skcipher_request - Symmetric key cipher request 17 * @cryptlen: Number of bytes to encrypt or decrypt 18 * @iv: Initialisation Vector 19 * @src: Source SG list 20 * @dst: Destination SG list 21 * @base: Underlying async request request 22 * @__ctx: Start of private context data 23 */ 24 struct skcipher_request { 25 unsigned int cryptlen; 26 27 u8 *iv; 28 29 struct scatterlist *src; 30 struct scatterlist *dst; 31 32 struct crypto_async_request base; 33 34 void *__ctx[] CRYPTO_MINALIGN_ATTR; 35 }; 36 37 struct crypto_skcipher { 38 int (*setkey)(struct crypto_skcipher *tfm, const u8 *key, 39 unsigned int keylen); 40 int (*encrypt)(struct skcipher_request *req); 41 int (*decrypt)(struct skcipher_request *req); 42 43 unsigned int ivsize; 44 unsigned int reqsize; 45 unsigned int keysize; 46 47 struct crypto_tfm base; 48 }; 49 50 struct crypto_sync_skcipher { 51 struct crypto_skcipher base; 52 }; 53 54 /** 55 * struct skcipher_alg - symmetric key cipher definition 56 * @min_keysize: Minimum key size supported by the transformation. This is the 57 * smallest key length supported by this transformation algorithm. 58 * This must be set to one of the pre-defined values as this is 59 * not hardware specific. Possible values for this field can be 60 * found via git grep "_MIN_KEY_SIZE" include/crypto/ 61 * @max_keysize: Maximum key size supported by the transformation. This is the 62 * largest key length supported by this transformation algorithm. 63 * This must be set to one of the pre-defined values as this is 64 * not hardware specific. Possible values for this field can be 65 * found via git grep "_MAX_KEY_SIZE" include/crypto/ 66 * @setkey: Set key for the transformation. This function is used to either 67 * program a supplied key into the hardware or store the key in the 68 * transformation context for programming it later. Note that this 69 * function does modify the transformation context. This function can 70 * be called multiple times during the existence of the transformation 71 * object, so one must make sure the key is properly reprogrammed into 72 * the hardware. This function is also responsible for checking the key 73 * length for validity. In case a software fallback was put in place in 74 * the @cra_init call, this function might need to use the fallback if 75 * the algorithm doesn't support all of the key sizes. 76 * @encrypt: Encrypt a scatterlist of blocks. This function is used to encrypt 77 * the supplied scatterlist containing the blocks of data. The crypto 78 * API consumer is responsible for aligning the entries of the 79 * scatterlist properly and making sure the chunks are correctly 80 * sized. In case a software fallback was put in place in the 81 * @cra_init call, this function might need to use the fallback if 82 * the algorithm doesn't support all of the key sizes. In case the 83 * key was stored in transformation context, the key might need to be 84 * re-programmed into the hardware in this function. This function 85 * shall not modify the transformation context, as this function may 86 * be called in parallel with the same transformation object. 87 * @decrypt: Decrypt a single block. This is a reverse counterpart to @encrypt 88 * and the conditions are exactly the same. 89 * @init: Initialize the cryptographic transformation object. This function 90 * is used to initialize the cryptographic transformation object. 91 * This function is called only once at the instantiation time, right 92 * after the transformation context was allocated. In case the 93 * cryptographic hardware has some special requirements which need to 94 * be handled by software, this function shall check for the precise 95 * requirement of the transformation and put any software fallbacks 96 * in place. 97 * @exit: Deinitialize the cryptographic transformation object. This is a 98 * counterpart to @init, used to remove various changes set in 99 * @init. 100 * @ivsize: IV size applicable for transformation. The consumer must provide an 101 * IV of exactly that size to perform the encrypt or decrypt operation. 102 * @chunksize: Equal to the block size except for stream ciphers such as 103 * CTR where it is set to the underlying block size. 104 * @walksize: Equal to the chunk size except in cases where the algorithm is 105 * considerably more efficient if it can operate on multiple chunks 106 * in parallel. Should be a multiple of chunksize. 107 * @base: Definition of a generic crypto algorithm. 108 * 109 * All fields except @ivsize are mandatory and must be filled. 110 */ 111 struct skcipher_alg { 112 int (*setkey)(struct crypto_skcipher *tfm, const u8 *key, 113 unsigned int keylen); 114 int (*encrypt)(struct skcipher_request *req); 115 int (*decrypt)(struct skcipher_request *req); 116 int (*init)(struct crypto_skcipher *tfm); 117 void (*exit)(struct crypto_skcipher *tfm); 118 119 unsigned int min_keysize; 120 unsigned int max_keysize; 121 unsigned int ivsize; 122 unsigned int chunksize; 123 unsigned int walksize; 124 125 struct crypto_alg base; 126 }; 127 128 #define MAX_SYNC_SKCIPHER_REQSIZE 384 129 /* 130 * This performs a type-check against the "tfm" argument to make sure 131 * all users have the correct skcipher tfm for doing on-stack requests. 132 */ 133 #define SYNC_SKCIPHER_REQUEST_ON_STACK(name, tfm) \ 134 char __##name##_desc[sizeof(struct skcipher_request) + \ 135 MAX_SYNC_SKCIPHER_REQSIZE + \ 136 (!(sizeof((struct crypto_sync_skcipher *)1 == \ 137 (typeof(tfm))1))) \ 138 ] CRYPTO_MINALIGN_ATTR; \ 139 struct skcipher_request *name = (void *)__##name##_desc 140 141 /** 142 * DOC: Symmetric Key Cipher API 143 * 144 * Symmetric key cipher API is used with the ciphers of type 145 * CRYPTO_ALG_TYPE_SKCIPHER (listed as type "skcipher" in /proc/crypto). 146 * 147 * Asynchronous cipher operations imply that the function invocation for a 148 * cipher request returns immediately before the completion of the operation. 149 * The cipher request is scheduled as a separate kernel thread and therefore 150 * load-balanced on the different CPUs via the process scheduler. To allow 151 * the kernel crypto API to inform the caller about the completion of a cipher 152 * request, the caller must provide a callback function. That function is 153 * invoked with the cipher handle when the request completes. 154 * 155 * To support the asynchronous operation, additional information than just the 156 * cipher handle must be supplied to the kernel crypto API. That additional 157 * information is given by filling in the skcipher_request data structure. 158 * 159 * For the symmetric key cipher API, the state is maintained with the tfm 160 * cipher handle. A single tfm can be used across multiple calls and in 161 * parallel. For asynchronous block cipher calls, context data supplied and 162 * only used by the caller can be referenced the request data structure in 163 * addition to the IV used for the cipher request. The maintenance of such 164 * state information would be important for a crypto driver implementer to 165 * have, because when calling the callback function upon completion of the 166 * cipher operation, that callback function may need some information about 167 * which operation just finished if it invoked multiple in parallel. This 168 * state information is unused by the kernel crypto API. 169 */ 170 171 static inline struct crypto_skcipher *__crypto_skcipher_cast( 172 struct crypto_tfm *tfm) 173 { 174 return container_of(tfm, struct crypto_skcipher, base); 175 } 176 177 /** 178 * crypto_alloc_skcipher() - allocate symmetric key cipher handle 179 * @alg_name: is the cra_name / name or cra_driver_name / driver name of the 180 * skcipher cipher 181 * @type: specifies the type of the cipher 182 * @mask: specifies the mask for the cipher 183 * 184 * Allocate a cipher handle for an skcipher. The returned struct 185 * crypto_skcipher is the cipher handle that is required for any subsequent 186 * API invocation for that skcipher. 187 * 188 * Return: allocated cipher handle in case of success; IS_ERR() is true in case 189 * of an error, PTR_ERR() returns the error code. 190 */ 191 struct crypto_skcipher *crypto_alloc_skcipher(const char *alg_name, 192 u32 type, u32 mask); 193 194 struct crypto_sync_skcipher *crypto_alloc_sync_skcipher(const char *alg_name, 195 u32 type, u32 mask); 196 197 static inline struct crypto_tfm *crypto_skcipher_tfm( 198 struct crypto_skcipher *tfm) 199 { 200 return &tfm->base; 201 } 202 203 /** 204 * crypto_free_skcipher() - zeroize and free cipher handle 205 * @tfm: cipher handle to be freed 206 */ 207 static inline void crypto_free_skcipher(struct crypto_skcipher *tfm) 208 { 209 crypto_destroy_tfm(tfm, crypto_skcipher_tfm(tfm)); 210 } 211 212 static inline void crypto_free_sync_skcipher(struct crypto_sync_skcipher *tfm) 213 { 214 crypto_free_skcipher(&tfm->base); 215 } 216 217 /** 218 * crypto_has_skcipher() - Search for the availability of an skcipher. 219 * @alg_name: is the cra_name / name or cra_driver_name / driver name of the 220 * skcipher 221 * @type: specifies the type of the cipher 222 * @mask: specifies the mask for the cipher 223 * 224 * Return: true when the skcipher is known to the kernel crypto API; false 225 * otherwise 226 */ 227 static inline int crypto_has_skcipher(const char *alg_name, u32 type, 228 u32 mask) 229 { 230 return crypto_has_alg(alg_name, crypto_skcipher_type(type), 231 crypto_skcipher_mask(mask)); 232 } 233 234 /** 235 * crypto_has_skcipher2() - Search for the availability of an skcipher. 236 * @alg_name: is the cra_name / name or cra_driver_name / driver name of the 237 * skcipher 238 * @type: specifies the type of the skcipher 239 * @mask: specifies the mask for the skcipher 240 * 241 * Return: true when the skcipher is known to the kernel crypto API; false 242 * otherwise 243 */ 244 int crypto_has_skcipher2(const char *alg_name, u32 type, u32 mask); 245 246 static inline const char *crypto_skcipher_driver_name( 247 struct crypto_skcipher *tfm) 248 { 249 return crypto_tfm_alg_driver_name(crypto_skcipher_tfm(tfm)); 250 } 251 252 static inline struct skcipher_alg *crypto_skcipher_alg( 253 struct crypto_skcipher *tfm) 254 { 255 return container_of(crypto_skcipher_tfm(tfm)->__crt_alg, 256 struct skcipher_alg, base); 257 } 258 259 static inline unsigned int crypto_skcipher_alg_ivsize(struct skcipher_alg *alg) 260 { 261 if ((alg->base.cra_flags & CRYPTO_ALG_TYPE_MASK) == 262 CRYPTO_ALG_TYPE_BLKCIPHER) 263 return alg->base.cra_blkcipher.ivsize; 264 265 if (alg->base.cra_ablkcipher.encrypt) 266 return alg->base.cra_ablkcipher.ivsize; 267 268 return alg->ivsize; 269 } 270 271 /** 272 * crypto_skcipher_ivsize() - obtain IV size 273 * @tfm: cipher handle 274 * 275 * The size of the IV for the skcipher referenced by the cipher handle is 276 * returned. This IV size may be zero if the cipher does not need an IV. 277 * 278 * Return: IV size in bytes 279 */ 280 static inline unsigned int crypto_skcipher_ivsize(struct crypto_skcipher *tfm) 281 { 282 return tfm->ivsize; 283 } 284 285 static inline unsigned int crypto_sync_skcipher_ivsize( 286 struct crypto_sync_skcipher *tfm) 287 { 288 return crypto_skcipher_ivsize(&tfm->base); 289 } 290 291 static inline unsigned int crypto_skcipher_alg_chunksize( 292 struct skcipher_alg *alg) 293 { 294 if ((alg->base.cra_flags & CRYPTO_ALG_TYPE_MASK) == 295 CRYPTO_ALG_TYPE_BLKCIPHER) 296 return alg->base.cra_blocksize; 297 298 if (alg->base.cra_ablkcipher.encrypt) 299 return alg->base.cra_blocksize; 300 301 return alg->chunksize; 302 } 303 304 static inline unsigned int crypto_skcipher_alg_walksize( 305 struct skcipher_alg *alg) 306 { 307 if ((alg->base.cra_flags & CRYPTO_ALG_TYPE_MASK) == 308 CRYPTO_ALG_TYPE_BLKCIPHER) 309 return alg->base.cra_blocksize; 310 311 if (alg->base.cra_ablkcipher.encrypt) 312 return alg->base.cra_blocksize; 313 314 return alg->walksize; 315 } 316 317 /** 318 * crypto_skcipher_chunksize() - obtain chunk size 319 * @tfm: cipher handle 320 * 321 * The block size is set to one for ciphers such as CTR. However, 322 * you still need to provide incremental updates in multiples of 323 * the underlying block size as the IV does not have sub-block 324 * granularity. This is known in this API as the chunk size. 325 * 326 * Return: chunk size in bytes 327 */ 328 static inline unsigned int crypto_skcipher_chunksize( 329 struct crypto_skcipher *tfm) 330 { 331 return crypto_skcipher_alg_chunksize(crypto_skcipher_alg(tfm)); 332 } 333 334 /** 335 * crypto_skcipher_walksize() - obtain walk size 336 * @tfm: cipher handle 337 * 338 * In some cases, algorithms can only perform optimally when operating on 339 * multiple blocks in parallel. This is reflected by the walksize, which 340 * must be a multiple of the chunksize (or equal if the concern does not 341 * apply) 342 * 343 * Return: walk size in bytes 344 */ 345 static inline unsigned int crypto_skcipher_walksize( 346 struct crypto_skcipher *tfm) 347 { 348 return crypto_skcipher_alg_walksize(crypto_skcipher_alg(tfm)); 349 } 350 351 /** 352 * crypto_skcipher_blocksize() - obtain block size of cipher 353 * @tfm: cipher handle 354 * 355 * The block size for the skcipher referenced with the cipher handle is 356 * returned. The caller may use that information to allocate appropriate 357 * memory for the data returned by the encryption or decryption operation 358 * 359 * Return: block size of cipher 360 */ 361 static inline unsigned int crypto_skcipher_blocksize( 362 struct crypto_skcipher *tfm) 363 { 364 return crypto_tfm_alg_blocksize(crypto_skcipher_tfm(tfm)); 365 } 366 367 static inline unsigned int crypto_sync_skcipher_blocksize( 368 struct crypto_sync_skcipher *tfm) 369 { 370 return crypto_skcipher_blocksize(&tfm->base); 371 } 372 373 static inline unsigned int crypto_skcipher_alignmask( 374 struct crypto_skcipher *tfm) 375 { 376 return crypto_tfm_alg_alignmask(crypto_skcipher_tfm(tfm)); 377 } 378 379 static inline u32 crypto_skcipher_get_flags(struct crypto_skcipher *tfm) 380 { 381 return crypto_tfm_get_flags(crypto_skcipher_tfm(tfm)); 382 } 383 384 static inline void crypto_skcipher_set_flags(struct crypto_skcipher *tfm, 385 u32 flags) 386 { 387 crypto_tfm_set_flags(crypto_skcipher_tfm(tfm), flags); 388 } 389 390 static inline void crypto_skcipher_clear_flags(struct crypto_skcipher *tfm, 391 u32 flags) 392 { 393 crypto_tfm_clear_flags(crypto_skcipher_tfm(tfm), flags); 394 } 395 396 static inline u32 crypto_sync_skcipher_get_flags( 397 struct crypto_sync_skcipher *tfm) 398 { 399 return crypto_skcipher_get_flags(&tfm->base); 400 } 401 402 static inline void crypto_sync_skcipher_set_flags( 403 struct crypto_sync_skcipher *tfm, u32 flags) 404 { 405 crypto_skcipher_set_flags(&tfm->base, flags); 406 } 407 408 static inline void crypto_sync_skcipher_clear_flags( 409 struct crypto_sync_skcipher *tfm, u32 flags) 410 { 411 crypto_skcipher_clear_flags(&tfm->base, flags); 412 } 413 414 /** 415 * crypto_skcipher_setkey() - set key for cipher 416 * @tfm: cipher handle 417 * @key: buffer holding the key 418 * @keylen: length of the key in bytes 419 * 420 * The caller provided key is set for the skcipher referenced by the cipher 421 * handle. 422 * 423 * Note, the key length determines the cipher type. Many block ciphers implement 424 * different cipher modes depending on the key size, such as AES-128 vs AES-192 425 * vs. AES-256. When providing a 16 byte key for an AES cipher handle, AES-128 426 * is performed. 427 * 428 * Return: 0 if the setting of the key was successful; < 0 if an error occurred 429 */ 430 static inline int crypto_skcipher_setkey(struct crypto_skcipher *tfm, 431 const u8 *key, unsigned int keylen) 432 { 433 return tfm->setkey(tfm, key, keylen); 434 } 435 436 static inline int crypto_sync_skcipher_setkey(struct crypto_sync_skcipher *tfm, 437 const u8 *key, unsigned int keylen) 438 { 439 return crypto_skcipher_setkey(&tfm->base, key, keylen); 440 } 441 442 static inline unsigned int crypto_skcipher_default_keysize( 443 struct crypto_skcipher *tfm) 444 { 445 return tfm->keysize; 446 } 447 448 /** 449 * crypto_skcipher_reqtfm() - obtain cipher handle from request 450 * @req: skcipher_request out of which the cipher handle is to be obtained 451 * 452 * Return the crypto_skcipher handle when furnishing an skcipher_request 453 * data structure. 454 * 455 * Return: crypto_skcipher handle 456 */ 457 static inline struct crypto_skcipher *crypto_skcipher_reqtfm( 458 struct skcipher_request *req) 459 { 460 return __crypto_skcipher_cast(req->base.tfm); 461 } 462 463 static inline struct crypto_sync_skcipher *crypto_sync_skcipher_reqtfm( 464 struct skcipher_request *req) 465 { 466 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); 467 468 return container_of(tfm, struct crypto_sync_skcipher, base); 469 } 470 471 /** 472 * crypto_skcipher_encrypt() - encrypt plaintext 473 * @req: reference to the skcipher_request handle that holds all information 474 * needed to perform the cipher operation 475 * 476 * Encrypt plaintext data using the skcipher_request handle. That data 477 * structure and how it is filled with data is discussed with the 478 * skcipher_request_* functions. 479 * 480 * Return: 0 if the cipher operation was successful; < 0 if an error occurred 481 */ 482 static inline int crypto_skcipher_encrypt(struct skcipher_request *req) 483 { 484 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); 485 struct crypto_alg *alg = tfm->base.__crt_alg; 486 unsigned int cryptlen = req->cryptlen; 487 int ret; 488 489 crypto_stats_get(alg); 490 if (crypto_skcipher_get_flags(tfm) & CRYPTO_TFM_NEED_KEY) 491 ret = -ENOKEY; 492 else 493 ret = tfm->encrypt(req); 494 crypto_stats_skcipher_encrypt(cryptlen, ret, alg); 495 return ret; 496 } 497 498 /** 499 * crypto_skcipher_decrypt() - decrypt ciphertext 500 * @req: reference to the skcipher_request handle that holds all information 501 * needed to perform the cipher operation 502 * 503 * Decrypt ciphertext data using the skcipher_request handle. That data 504 * structure and how it is filled with data is discussed with the 505 * skcipher_request_* functions. 506 * 507 * Return: 0 if the cipher operation was successful; < 0 if an error occurred 508 */ 509 static inline int crypto_skcipher_decrypt(struct skcipher_request *req) 510 { 511 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); 512 struct crypto_alg *alg = tfm->base.__crt_alg; 513 unsigned int cryptlen = req->cryptlen; 514 int ret; 515 516 crypto_stats_get(alg); 517 if (crypto_skcipher_get_flags(tfm) & CRYPTO_TFM_NEED_KEY) 518 ret = -ENOKEY; 519 else 520 ret = tfm->decrypt(req); 521 crypto_stats_skcipher_decrypt(cryptlen, ret, alg); 522 return ret; 523 } 524 525 /** 526 * DOC: Symmetric Key Cipher Request Handle 527 * 528 * The skcipher_request data structure contains all pointers to data 529 * required for the symmetric key cipher operation. This includes the cipher 530 * handle (which can be used by multiple skcipher_request instances), pointer 531 * to plaintext and ciphertext, asynchronous callback function, etc. It acts 532 * as a handle to the skcipher_request_* API calls in a similar way as 533 * skcipher handle to the crypto_skcipher_* API calls. 534 */ 535 536 /** 537 * crypto_skcipher_reqsize() - obtain size of the request data structure 538 * @tfm: cipher handle 539 * 540 * Return: number of bytes 541 */ 542 static inline unsigned int crypto_skcipher_reqsize(struct crypto_skcipher *tfm) 543 { 544 return tfm->reqsize; 545 } 546 547 /** 548 * skcipher_request_set_tfm() - update cipher handle reference in request 549 * @req: request handle to be modified 550 * @tfm: cipher handle that shall be added to the request handle 551 * 552 * Allow the caller to replace the existing skcipher handle in the request 553 * data structure with a different one. 554 */ 555 static inline void skcipher_request_set_tfm(struct skcipher_request *req, 556 struct crypto_skcipher *tfm) 557 { 558 req->base.tfm = crypto_skcipher_tfm(tfm); 559 } 560 561 static inline void skcipher_request_set_sync_tfm(struct skcipher_request *req, 562 struct crypto_sync_skcipher *tfm) 563 { 564 skcipher_request_set_tfm(req, &tfm->base); 565 } 566 567 static inline struct skcipher_request *skcipher_request_cast( 568 struct crypto_async_request *req) 569 { 570 return container_of(req, struct skcipher_request, base); 571 } 572 573 /** 574 * skcipher_request_alloc() - allocate request data structure 575 * @tfm: cipher handle to be registered with the request 576 * @gfp: memory allocation flag that is handed to kmalloc by the API call. 577 * 578 * Allocate the request data structure that must be used with the skcipher 579 * encrypt and decrypt API calls. During the allocation, the provided skcipher 580 * handle is registered in the request data structure. 581 * 582 * Return: allocated request handle in case of success, or NULL if out of memory 583 */ 584 static inline struct skcipher_request *skcipher_request_alloc( 585 struct crypto_skcipher *tfm, gfp_t gfp) 586 { 587 struct skcipher_request *req; 588 589 req = kmalloc(sizeof(struct skcipher_request) + 590 crypto_skcipher_reqsize(tfm), gfp); 591 592 if (likely(req)) 593 skcipher_request_set_tfm(req, tfm); 594 595 return req; 596 } 597 598 /** 599 * skcipher_request_free() - zeroize and free request data structure 600 * @req: request data structure cipher handle to be freed 601 */ 602 static inline void skcipher_request_free(struct skcipher_request *req) 603 { 604 kzfree(req); 605 } 606 607 static inline void skcipher_request_zero(struct skcipher_request *req) 608 { 609 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); 610 611 memzero_explicit(req, sizeof(*req) + crypto_skcipher_reqsize(tfm)); 612 } 613 614 /** 615 * skcipher_request_set_callback() - set asynchronous callback function 616 * @req: request handle 617 * @flags: specify zero or an ORing of the flags 618 * CRYPTO_TFM_REQ_MAY_BACKLOG the request queue may back log and 619 * increase the wait queue beyond the initial maximum size; 620 * CRYPTO_TFM_REQ_MAY_SLEEP the request processing may sleep 621 * @compl: callback function pointer to be registered with the request handle 622 * @data: The data pointer refers to memory that is not used by the kernel 623 * crypto API, but provided to the callback function for it to use. Here, 624 * the caller can provide a reference to memory the callback function can 625 * operate on. As the callback function is invoked asynchronously to the 626 * related functionality, it may need to access data structures of the 627 * related functionality which can be referenced using this pointer. The 628 * callback function can access the memory via the "data" field in the 629 * crypto_async_request data structure provided to the callback function. 630 * 631 * This function allows setting the callback function that is triggered once the 632 * cipher operation completes. 633 * 634 * The callback function is registered with the skcipher_request handle and 635 * must comply with the following template:: 636 * 637 * void callback_function(struct crypto_async_request *req, int error) 638 */ 639 static inline void skcipher_request_set_callback(struct skcipher_request *req, 640 u32 flags, 641 crypto_completion_t compl, 642 void *data) 643 { 644 req->base.complete = compl; 645 req->base.data = data; 646 req->base.flags = flags; 647 } 648 649 /** 650 * skcipher_request_set_crypt() - set data buffers 651 * @req: request handle 652 * @src: source scatter / gather list 653 * @dst: destination scatter / gather list 654 * @cryptlen: number of bytes to process from @src 655 * @iv: IV for the cipher operation which must comply with the IV size defined 656 * by crypto_skcipher_ivsize 657 * 658 * This function allows setting of the source data and destination data 659 * scatter / gather lists. 660 * 661 * For encryption, the source is treated as the plaintext and the 662 * destination is the ciphertext. For a decryption operation, the use is 663 * reversed - the source is the ciphertext and the destination is the plaintext. 664 */ 665 static inline void skcipher_request_set_crypt( 666 struct skcipher_request *req, 667 struct scatterlist *src, struct scatterlist *dst, 668 unsigned int cryptlen, void *iv) 669 { 670 req->src = src; 671 req->dst = dst; 672 req->cryptlen = cryptlen; 673 req->iv = iv; 674 } 675 676 #endif /* _CRYPTO_SKCIPHER_H */ 677 678