1 /* SPDX-License-Identifier: GPL-2.0-or-later */ 2 /* 3 * Scatterlist Cryptographic API. 4 * 5 * Copyright (c) 2002 James Morris <[email protected]> 6 * Copyright (c) 2002 David S. Miller ([email protected]) 7 * Copyright (c) 2005 Herbert Xu <[email protected]> 8 * 9 * Portions derived from Cryptoapi, by Alexander Kjeldaas <[email protected]> 10 * and Nettle, by Niels Möller. 11 */ 12 #ifndef _LINUX_CRYPTO_H 13 #define _LINUX_CRYPTO_H 14 15 #include <linux/completion.h> 16 #include <linux/errno.h> 17 #include <linux/list.h> 18 #include <linux/refcount.h> 19 #include <linux/slab.h> 20 #include <linux/types.h> 21 22 /* 23 * Algorithm masks and types. 24 */ 25 #define CRYPTO_ALG_TYPE_MASK 0x0000000f 26 #define CRYPTO_ALG_TYPE_CIPHER 0x00000001 27 #define CRYPTO_ALG_TYPE_COMPRESS 0x00000002 28 #define CRYPTO_ALG_TYPE_AEAD 0x00000003 29 #define CRYPTO_ALG_TYPE_LSKCIPHER 0x00000004 30 #define CRYPTO_ALG_TYPE_SKCIPHER 0x00000005 31 #define CRYPTO_ALG_TYPE_AKCIPHER 0x00000006 32 #define CRYPTO_ALG_TYPE_SIG 0x00000007 33 #define CRYPTO_ALG_TYPE_KPP 0x00000008 34 #define CRYPTO_ALG_TYPE_ACOMPRESS 0x0000000a 35 #define CRYPTO_ALG_TYPE_SCOMPRESS 0x0000000b 36 #define CRYPTO_ALG_TYPE_RNG 0x0000000c 37 #define CRYPTO_ALG_TYPE_HASH 0x0000000e 38 #define CRYPTO_ALG_TYPE_SHASH 0x0000000e 39 #define CRYPTO_ALG_TYPE_AHASH 0x0000000f 40 41 #define CRYPTO_ALG_TYPE_ACOMPRESS_MASK 0x0000000e 42 43 #define CRYPTO_ALG_LARVAL 0x00000010 44 #define CRYPTO_ALG_DEAD 0x00000020 45 #define CRYPTO_ALG_DYING 0x00000040 46 #define CRYPTO_ALG_ASYNC 0x00000080 47 48 /* 49 * Set if the algorithm (or an algorithm which it uses) requires another 50 * algorithm of the same type to handle corner cases. 51 */ 52 #define CRYPTO_ALG_NEED_FALLBACK 0x00000100 53 54 /* 55 * Set if the algorithm has passed automated run-time testing. Note that 56 * if there is no run-time testing for a given algorithm it is considered 57 * to have passed. 58 */ 59 60 #define CRYPTO_ALG_TESTED 0x00000400 61 62 /* 63 * Set if the algorithm is an instance that is built from templates. 64 */ 65 #define CRYPTO_ALG_INSTANCE 0x00000800 66 67 /* Set this bit if the algorithm provided is hardware accelerated but 68 * not available to userspace via instruction set or so. 69 */ 70 #define CRYPTO_ALG_KERN_DRIVER_ONLY 0x00001000 71 72 /* 73 * Mark a cipher as a service implementation only usable by another 74 * cipher and never by a normal user of the kernel crypto API 75 */ 76 #define CRYPTO_ALG_INTERNAL 0x00002000 77 78 /* 79 * Set if the algorithm has a ->setkey() method but can be used without 80 * calling it first, i.e. there is a default key. 81 */ 82 #define CRYPTO_ALG_OPTIONAL_KEY 0x00004000 83 84 /* 85 * Don't trigger module loading 86 */ 87 #define CRYPTO_NOLOAD 0x00008000 88 89 /* 90 * The algorithm may allocate memory during request processing, i.e. during 91 * encryption, decryption, or hashing. Users can request an algorithm with this 92 * flag unset if they can't handle memory allocation failures. 93 * 94 * This flag is currently only implemented for algorithms of type "skcipher", 95 * "aead", "ahash", "shash", and "cipher". Algorithms of other types might not 96 * have this flag set even if they allocate memory. 97 * 98 * In some edge cases, algorithms can allocate memory regardless of this flag. 99 * To avoid these cases, users must obey the following usage constraints: 100 * skcipher: 101 * - The IV buffer and all scatterlist elements must be aligned to the 102 * algorithm's alignmask. 103 * - If the data were to be divided into chunks of size 104 * crypto_skcipher_walksize() (with any remainder going at the end), no 105 * chunk can cross a page boundary or a scatterlist element boundary. 106 * aead: 107 * - The IV buffer and all scatterlist elements must be aligned to the 108 * algorithm's alignmask. 109 * - The first scatterlist element must contain all the associated data, 110 * and its pages must be !PageHighMem. 111 * - If the plaintext/ciphertext were to be divided into chunks of size 112 * crypto_aead_walksize() (with the remainder going at the end), no chunk 113 * can cross a page boundary or a scatterlist element boundary. 114 * ahash: 115 * - crypto_ahash_finup() must not be used unless the algorithm implements 116 * ->finup() natively. 117 */ 118 #define CRYPTO_ALG_ALLOCATES_MEMORY 0x00010000 119 120 /* 121 * Mark an algorithm as a service implementation only usable by a 122 * template and never by a normal user of the kernel crypto API. 123 * This is intended to be used by algorithms that are themselves 124 * not FIPS-approved but may instead be used to implement parts of 125 * a FIPS-approved algorithm (e.g., dh vs. ffdhe2048(dh)). 126 */ 127 #define CRYPTO_ALG_FIPS_INTERNAL 0x00020000 128 129 /* Set if the algorithm supports request chains and virtual addresses. */ 130 #define CRYPTO_ALG_REQ_CHAIN 0x00040000 131 132 /* 133 * Transform masks and values (for crt_flags). 134 */ 135 #define CRYPTO_TFM_NEED_KEY 0x00000001 136 137 #define CRYPTO_TFM_REQ_MASK 0x000fff00 138 #define CRYPTO_TFM_REQ_FORBID_WEAK_KEYS 0x00000100 139 #define CRYPTO_TFM_REQ_MAY_SLEEP 0x00000200 140 #define CRYPTO_TFM_REQ_MAY_BACKLOG 0x00000400 141 #define CRYPTO_TFM_REQ_ON_STACK 0x00000800 142 143 /* 144 * Miscellaneous stuff. 145 */ 146 #define CRYPTO_MAX_ALG_NAME 128 147 148 /* 149 * The macro CRYPTO_MINALIGN_ATTR (along with the void * type in the actual 150 * declaration) is used to ensure that the crypto_tfm context structure is 151 * aligned correctly for the given architecture so that there are no alignment 152 * faults for C data types. On architectures that support non-cache coherent 153 * DMA, such as ARM or arm64, it also takes into account the minimal alignment 154 * that is required to ensure that the context struct member does not share any 155 * cachelines with the rest of the struct. This is needed to ensure that cache 156 * maintenance for non-coherent DMA (cache invalidation in particular) does not 157 * affect data that may be accessed by the CPU concurrently. 158 */ 159 #define CRYPTO_MINALIGN ARCH_KMALLOC_MINALIGN 160 161 #define CRYPTO_MINALIGN_ATTR __attribute__ ((__aligned__(CRYPTO_MINALIGN))) 162 163 struct crypto_tfm; 164 struct crypto_type; 165 struct module; 166 167 typedef void (*crypto_completion_t)(void *req, int err); 168 169 /** 170 * DOC: Block Cipher Context Data Structures 171 * 172 * These data structures define the operating context for each block cipher 173 * type. 174 */ 175 176 struct crypto_async_request { 177 struct list_head list; 178 crypto_completion_t complete; 179 void *data; 180 struct crypto_tfm *tfm; 181 182 u32 flags; 183 int err; 184 }; 185 186 /** 187 * DOC: Block Cipher Algorithm Definitions 188 * 189 * These data structures define modular crypto algorithm implementations, 190 * managed via crypto_register_alg() and crypto_unregister_alg(). 191 */ 192 193 /** 194 * struct cipher_alg - single-block symmetric ciphers definition 195 * @cia_min_keysize: Minimum key size supported by the transformation. This is 196 * the smallest key length supported by this transformation 197 * algorithm. This must be set to one of the pre-defined 198 * values as this is not hardware specific. Possible values 199 * for this field can be found via git grep "_MIN_KEY_SIZE" 200 * include/crypto/ 201 * @cia_max_keysize: Maximum key size supported by the transformation. This is 202 * the largest key length supported by this transformation 203 * algorithm. This must be set to one of the pre-defined values 204 * as this is not hardware specific. Possible values for this 205 * field can be found via git grep "_MAX_KEY_SIZE" 206 * include/crypto/ 207 * @cia_setkey: Set key for the transformation. This function is used to either 208 * program a supplied key into the hardware or store the key in the 209 * transformation context for programming it later. Note that this 210 * function does modify the transformation context. This function 211 * can be called multiple times during the existence of the 212 * transformation object, so one must make sure the key is properly 213 * reprogrammed into the hardware. This function is also 214 * responsible for checking the key length for validity. 215 * @cia_encrypt: Encrypt a single block. This function is used to encrypt a 216 * single block of data, which must be @cra_blocksize big. This 217 * always operates on a full @cra_blocksize and it is not possible 218 * to encrypt a block of smaller size. The supplied buffers must 219 * therefore also be at least of @cra_blocksize size. Both the 220 * input and output buffers are always aligned to @cra_alignmask. 221 * In case either of the input or output buffer supplied by user 222 * of the crypto API is not aligned to @cra_alignmask, the crypto 223 * API will re-align the buffers. The re-alignment means that a 224 * new buffer will be allocated, the data will be copied into the 225 * new buffer, then the processing will happen on the new buffer, 226 * then the data will be copied back into the original buffer and 227 * finally the new buffer will be freed. In case a software 228 * fallback was put in place in the @cra_init call, this function 229 * might need to use the fallback if the algorithm doesn't support 230 * all of the key sizes. In case the key was stored in 231 * transformation context, the key might need to be re-programmed 232 * into the hardware in this function. This function shall not 233 * modify the transformation context, as this function may be 234 * called in parallel with the same transformation object. 235 * @cia_decrypt: Decrypt a single block. This is a reverse counterpart to 236 * @cia_encrypt, and the conditions are exactly the same. 237 * 238 * All fields are mandatory and must be filled. 239 */ 240 struct cipher_alg { 241 unsigned int cia_min_keysize; 242 unsigned int cia_max_keysize; 243 int (*cia_setkey)(struct crypto_tfm *tfm, const u8 *key, 244 unsigned int keylen); 245 void (*cia_encrypt)(struct crypto_tfm *tfm, u8 *dst, const u8 *src); 246 void (*cia_decrypt)(struct crypto_tfm *tfm, u8 *dst, const u8 *src); 247 }; 248 249 /** 250 * struct compress_alg - compression/decompression algorithm 251 * @coa_compress: Compress a buffer of specified length, storing the resulting 252 * data in the specified buffer. Return the length of the 253 * compressed data in dlen. 254 * @coa_decompress: Decompress the source buffer, storing the uncompressed 255 * data in the specified buffer. The length of the data is 256 * returned in dlen. 257 * 258 * All fields are mandatory. 259 */ 260 struct compress_alg { 261 int (*coa_compress)(struct crypto_tfm *tfm, const u8 *src, 262 unsigned int slen, u8 *dst, unsigned int *dlen); 263 int (*coa_decompress)(struct crypto_tfm *tfm, const u8 *src, 264 unsigned int slen, u8 *dst, unsigned int *dlen); 265 }; 266 267 #define cra_cipher cra_u.cipher 268 #define cra_compress cra_u.compress 269 270 /** 271 * struct crypto_alg - definition of a cryptograpic cipher algorithm 272 * @cra_flags: Flags describing this transformation. See include/linux/crypto.h 273 * CRYPTO_ALG_* flags for the flags which go in here. Those are 274 * used for fine-tuning the description of the transformation 275 * algorithm. 276 * @cra_blocksize: Minimum block size of this transformation. The size in bytes 277 * of the smallest possible unit which can be transformed with 278 * this algorithm. The users must respect this value. 279 * In case of HASH transformation, it is possible for a smaller 280 * block than @cra_blocksize to be passed to the crypto API for 281 * transformation, in case of any other transformation type, an 282 * error will be returned upon any attempt to transform smaller 283 * than @cra_blocksize chunks. 284 * @cra_ctxsize: Size of the operational context of the transformation. This 285 * value informs the kernel crypto API about the memory size 286 * needed to be allocated for the transformation context. 287 * @cra_alignmask: For cipher, skcipher, lskcipher, and aead algorithms this is 288 * 1 less than the alignment, in bytes, that the algorithm 289 * implementation requires for input and output buffers. When 290 * the crypto API is invoked with buffers that are not aligned 291 * to this alignment, the crypto API automatically utilizes 292 * appropriately aligned temporary buffers to comply with what 293 * the algorithm needs. (For scatterlists this happens only if 294 * the algorithm uses the skcipher_walk helper functions.) This 295 * misalignment handling carries a performance penalty, so it is 296 * preferred that algorithms do not set a nonzero alignmask. 297 * Also, crypto API users may wish to allocate buffers aligned 298 * to the alignmask of the algorithm being used, in order to 299 * avoid the API having to realign them. Note: the alignmask is 300 * not supported for hash algorithms and is always 0 for them. 301 * @cra_priority: Priority of this transformation implementation. In case 302 * multiple transformations with same @cra_name are available to 303 * the Crypto API, the kernel will use the one with highest 304 * @cra_priority. 305 * @cra_name: Generic name (usable by multiple implementations) of the 306 * transformation algorithm. This is the name of the transformation 307 * itself. This field is used by the kernel when looking up the 308 * providers of particular transformation. 309 * @cra_driver_name: Unique name of the transformation provider. This is the 310 * name of the provider of the transformation. This can be any 311 * arbitrary value, but in the usual case, this contains the 312 * name of the chip or provider and the name of the 313 * transformation algorithm. 314 * @cra_type: Type of the cryptographic transformation. This is a pointer to 315 * struct crypto_type, which implements callbacks common for all 316 * transformation types. There are multiple options, such as 317 * &crypto_skcipher_type, &crypto_ahash_type, &crypto_rng_type. 318 * This field might be empty. In that case, there are no common 319 * callbacks. This is the case for: cipher, compress, shash. 320 * @cra_u: Callbacks implementing the transformation. This is a union of 321 * multiple structures. Depending on the type of transformation selected 322 * by @cra_type and @cra_flags above, the associated structure must be 323 * filled with callbacks. This field might be empty. This is the case 324 * for ahash, shash. 325 * @cra_init: Initialize the cryptographic transformation object. This function 326 * is used to initialize the cryptographic transformation object. 327 * This function is called only once at the instantiation time, right 328 * after the transformation context was allocated. In case the 329 * cryptographic hardware has some special requirements which need to 330 * be handled by software, this function shall check for the precise 331 * requirement of the transformation and put any software fallbacks 332 * in place. 333 * @cra_exit: Deinitialize the cryptographic transformation object. This is a 334 * counterpart to @cra_init, used to remove various changes set in 335 * @cra_init. 336 * @cra_u.cipher: Union member which contains a single-block symmetric cipher 337 * definition. See @struct @cipher_alg. 338 * @cra_u.compress: Union member which contains a (de)compression algorithm. 339 * See @struct @compress_alg. 340 * @cra_module: Owner of this transformation implementation. Set to THIS_MODULE 341 * @cra_list: internally used 342 * @cra_users: internally used 343 * @cra_refcnt: internally used 344 * @cra_destroy: internally used 345 * 346 * The struct crypto_alg describes a generic Crypto API algorithm and is common 347 * for all of the transformations. Any variable not documented here shall not 348 * be used by a cipher implementation as it is internal to the Crypto API. 349 */ 350 struct crypto_alg { 351 struct list_head cra_list; 352 struct list_head cra_users; 353 354 u32 cra_flags; 355 unsigned int cra_blocksize; 356 unsigned int cra_ctxsize; 357 unsigned int cra_alignmask; 358 359 int cra_priority; 360 refcount_t cra_refcnt; 361 362 char cra_name[CRYPTO_MAX_ALG_NAME]; 363 char cra_driver_name[CRYPTO_MAX_ALG_NAME]; 364 365 const struct crypto_type *cra_type; 366 367 union { 368 struct cipher_alg cipher; 369 struct compress_alg compress; 370 } cra_u; 371 372 int (*cra_init)(struct crypto_tfm *tfm); 373 void (*cra_exit)(struct crypto_tfm *tfm); 374 void (*cra_destroy)(struct crypto_alg *alg); 375 376 struct module *cra_module; 377 } CRYPTO_MINALIGN_ATTR; 378 379 /* 380 * A helper struct for waiting for completion of async crypto ops 381 */ 382 struct crypto_wait { 383 struct completion completion; 384 int err; 385 }; 386 387 /* 388 * Macro for declaring a crypto op async wait object on stack 389 */ 390 #define DECLARE_CRYPTO_WAIT(_wait) \ 391 struct crypto_wait _wait = { \ 392 COMPLETION_INITIALIZER_ONSTACK((_wait).completion), 0 } 393 394 /* 395 * Async ops completion helper functioons 396 */ 397 void crypto_req_done(void *req, int err); 398 399 static inline int crypto_wait_req(int err, struct crypto_wait *wait) 400 { 401 switch (err) { 402 case -EINPROGRESS: 403 case -EBUSY: 404 wait_for_completion(&wait->completion); 405 reinit_completion(&wait->completion); 406 err = wait->err; 407 break; 408 } 409 410 return err; 411 } 412 413 static inline void crypto_init_wait(struct crypto_wait *wait) 414 { 415 init_completion(&wait->completion); 416 } 417 418 /* 419 * Algorithm query interface. 420 */ 421 int crypto_has_alg(const char *name, u32 type, u32 mask); 422 423 /* 424 * Transforms: user-instantiated objects which encapsulate algorithms 425 * and core processing logic. Managed via crypto_alloc_*() and 426 * crypto_free_*(), as well as the various helpers below. 427 */ 428 429 struct crypto_tfm { 430 refcount_t refcnt; 431 432 u32 crt_flags; 433 434 int node; 435 436 void (*exit)(struct crypto_tfm *tfm); 437 438 struct crypto_alg *__crt_alg; 439 440 void *__crt_ctx[] CRYPTO_MINALIGN_ATTR; 441 }; 442 443 struct crypto_comp { 444 struct crypto_tfm base; 445 }; 446 447 /* 448 * Transform user interface. 449 */ 450 451 struct crypto_tfm *crypto_alloc_base(const char *alg_name, u32 type, u32 mask); 452 void crypto_destroy_tfm(void *mem, struct crypto_tfm *tfm); 453 454 static inline void crypto_free_tfm(struct crypto_tfm *tfm) 455 { 456 return crypto_destroy_tfm(tfm, tfm); 457 } 458 459 /* 460 * Transform helpers which query the underlying algorithm. 461 */ 462 static inline const char *crypto_tfm_alg_name(struct crypto_tfm *tfm) 463 { 464 return tfm->__crt_alg->cra_name; 465 } 466 467 static inline const char *crypto_tfm_alg_driver_name(struct crypto_tfm *tfm) 468 { 469 return tfm->__crt_alg->cra_driver_name; 470 } 471 472 static inline unsigned int crypto_tfm_alg_blocksize(struct crypto_tfm *tfm) 473 { 474 return tfm->__crt_alg->cra_blocksize; 475 } 476 477 static inline unsigned int crypto_tfm_alg_alignmask(struct crypto_tfm *tfm) 478 { 479 return tfm->__crt_alg->cra_alignmask; 480 } 481 482 static inline u32 crypto_tfm_get_flags(struct crypto_tfm *tfm) 483 { 484 return tfm->crt_flags; 485 } 486 487 static inline void crypto_tfm_set_flags(struct crypto_tfm *tfm, u32 flags) 488 { 489 tfm->crt_flags |= flags; 490 } 491 492 static inline void crypto_tfm_clear_flags(struct crypto_tfm *tfm, u32 flags) 493 { 494 tfm->crt_flags &= ~flags; 495 } 496 497 static inline unsigned int crypto_tfm_ctx_alignment(void) 498 { 499 struct crypto_tfm *tfm; 500 return __alignof__(tfm->__crt_ctx); 501 } 502 503 static inline struct crypto_comp *__crypto_comp_cast(struct crypto_tfm *tfm) 504 { 505 return (struct crypto_comp *)tfm; 506 } 507 508 static inline struct crypto_comp *crypto_alloc_comp(const char *alg_name, 509 u32 type, u32 mask) 510 { 511 type &= ~CRYPTO_ALG_TYPE_MASK; 512 type |= CRYPTO_ALG_TYPE_COMPRESS; 513 mask |= CRYPTO_ALG_TYPE_MASK; 514 515 return __crypto_comp_cast(crypto_alloc_base(alg_name, type, mask)); 516 } 517 518 static inline struct crypto_tfm *crypto_comp_tfm(struct crypto_comp *tfm) 519 { 520 return &tfm->base; 521 } 522 523 static inline void crypto_free_comp(struct crypto_comp *tfm) 524 { 525 crypto_free_tfm(crypto_comp_tfm(tfm)); 526 } 527 528 static inline int crypto_has_comp(const char *alg_name, u32 type, u32 mask) 529 { 530 type &= ~CRYPTO_ALG_TYPE_MASK; 531 type |= CRYPTO_ALG_TYPE_COMPRESS; 532 mask |= CRYPTO_ALG_TYPE_MASK; 533 534 return crypto_has_alg(alg_name, type, mask); 535 } 536 537 static inline const char *crypto_comp_name(struct crypto_comp *tfm) 538 { 539 return crypto_tfm_alg_name(crypto_comp_tfm(tfm)); 540 } 541 542 int crypto_comp_compress(struct crypto_comp *tfm, 543 const u8 *src, unsigned int slen, 544 u8 *dst, unsigned int *dlen); 545 546 int crypto_comp_decompress(struct crypto_comp *tfm, 547 const u8 *src, unsigned int slen, 548 u8 *dst, unsigned int *dlen); 549 550 static inline void crypto_reqchain_init(struct crypto_async_request *req) 551 { 552 req->err = -EINPROGRESS; 553 INIT_LIST_HEAD(&req->list); 554 } 555 556 static inline void crypto_request_chain(struct crypto_async_request *req, 557 struct crypto_async_request *head) 558 { 559 req->err = -EINPROGRESS; 560 list_add_tail(&req->list, &head->list); 561 } 562 563 static inline bool crypto_tfm_is_async(struct crypto_tfm *tfm) 564 { 565 return tfm->__crt_alg->cra_flags & CRYPTO_ALG_ASYNC; 566 } 567 568 #endif /* _LINUX_CRYPTO_H */ 569 570