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/atomic.h> 16 #include <linux/kernel.h> 17 #include <linux/list.h> 18 #include <linux/bug.h> 19 #include <linux/refcount.h> 20 #include <linux/slab.h> 21 #include <linux/completion.h> 22 23 /* 24 * Autoloaded crypto modules should only use a prefixed name to avoid allowing 25 * arbitrary modules to be loaded. Loading from userspace may still need the 26 * unprefixed names, so retains those aliases as well. 27 * This uses __MODULE_INFO directly instead of MODULE_ALIAS because pre-4.3 28 * gcc (e.g. avr32 toolchain) uses __LINE__ for uniqueness, and this macro 29 * expands twice on the same line. Instead, use a separate base name for the 30 * alias. 31 */ 32 #define MODULE_ALIAS_CRYPTO(name) \ 33 __MODULE_INFO(alias, alias_userspace, name); \ 34 __MODULE_INFO(alias, alias_crypto, "crypto-" name) 35 36 /* 37 * Algorithm masks and types. 38 */ 39 #define CRYPTO_ALG_TYPE_MASK 0x0000000f 40 #define CRYPTO_ALG_TYPE_CIPHER 0x00000001 41 #define CRYPTO_ALG_TYPE_COMPRESS 0x00000002 42 #define CRYPTO_ALG_TYPE_AEAD 0x00000003 43 #define CRYPTO_ALG_TYPE_SKCIPHER 0x00000005 44 #define CRYPTO_ALG_TYPE_KPP 0x00000008 45 #define CRYPTO_ALG_TYPE_ACOMPRESS 0x0000000a 46 #define CRYPTO_ALG_TYPE_SCOMPRESS 0x0000000b 47 #define CRYPTO_ALG_TYPE_RNG 0x0000000c 48 #define CRYPTO_ALG_TYPE_AKCIPHER 0x0000000d 49 #define CRYPTO_ALG_TYPE_HASH 0x0000000e 50 #define CRYPTO_ALG_TYPE_SHASH 0x0000000e 51 #define CRYPTO_ALG_TYPE_AHASH 0x0000000f 52 53 #define CRYPTO_ALG_TYPE_HASH_MASK 0x0000000e 54 #define CRYPTO_ALG_TYPE_AHASH_MASK 0x0000000e 55 #define CRYPTO_ALG_TYPE_ACOMPRESS_MASK 0x0000000e 56 57 #define CRYPTO_ALG_LARVAL 0x00000010 58 #define CRYPTO_ALG_DEAD 0x00000020 59 #define CRYPTO_ALG_DYING 0x00000040 60 #define CRYPTO_ALG_ASYNC 0x00000080 61 62 /* 63 * Set if the algorithm (or an algorithm which it uses) requires another 64 * algorithm of the same type to handle corner cases. 65 */ 66 #define CRYPTO_ALG_NEED_FALLBACK 0x00000100 67 68 /* 69 * Set if the algorithm has passed automated run-time testing. Note that 70 * if there is no run-time testing for a given algorithm it is considered 71 * to have passed. 72 */ 73 74 #define CRYPTO_ALG_TESTED 0x00000400 75 76 /* 77 * Set if the algorithm is an instance that is built from templates. 78 */ 79 #define CRYPTO_ALG_INSTANCE 0x00000800 80 81 /* Set this bit if the algorithm provided is hardware accelerated but 82 * not available to userspace via instruction set or so. 83 */ 84 #define CRYPTO_ALG_KERN_DRIVER_ONLY 0x00001000 85 86 /* 87 * Mark a cipher as a service implementation only usable by another 88 * cipher and never by a normal user of the kernel crypto API 89 */ 90 #define CRYPTO_ALG_INTERNAL 0x00002000 91 92 /* 93 * Set if the algorithm has a ->setkey() method but can be used without 94 * calling it first, i.e. there is a default key. 95 */ 96 #define CRYPTO_ALG_OPTIONAL_KEY 0x00004000 97 98 /* 99 * Don't trigger module loading 100 */ 101 #define CRYPTO_NOLOAD 0x00008000 102 103 /* 104 * The algorithm may allocate memory during request processing, i.e. during 105 * encryption, decryption, or hashing. Users can request an algorithm with this 106 * flag unset if they can't handle memory allocation failures. 107 * 108 * This flag is currently only implemented for algorithms of type "skcipher", 109 * "aead", "ahash", "shash", and "cipher". Algorithms of other types might not 110 * have this flag set even if they allocate memory. 111 * 112 * In some edge cases, algorithms can allocate memory regardless of this flag. 113 * To avoid these cases, users must obey the following usage constraints: 114 * skcipher: 115 * - The IV buffer and all scatterlist elements must be aligned to the 116 * algorithm's alignmask. 117 * - If the data were to be divided into chunks of size 118 * crypto_skcipher_walksize() (with any remainder going at the end), no 119 * chunk can cross a page boundary or a scatterlist element boundary. 120 * aead: 121 * - The IV buffer and all scatterlist elements must be aligned to the 122 * algorithm's alignmask. 123 * - The first scatterlist element must contain all the associated data, 124 * and its pages must be !PageHighMem. 125 * - If the plaintext/ciphertext were to be divided into chunks of size 126 * crypto_aead_walksize() (with the remainder going at the end), no chunk 127 * can cross a page boundary or a scatterlist element boundary. 128 * ahash: 129 * - The result buffer must be aligned to the algorithm's alignmask. 130 * - crypto_ahash_finup() must not be used unless the algorithm implements 131 * ->finup() natively. 132 */ 133 #define CRYPTO_ALG_ALLOCATES_MEMORY 0x00010000 134 135 /* 136 * Mark an algorithm as a service implementation only usable by a 137 * template and never by a normal user of the kernel crypto API. 138 * This is intended to be used by algorithms that are themselves 139 * not FIPS-approved but may instead be used to implement parts of 140 * a FIPS-approved algorithm (e.g., dh vs. ffdhe2048(dh)). 141 */ 142 #define CRYPTO_ALG_FIPS_INTERNAL 0x00020000 143 144 /* 145 * Transform masks and values (for crt_flags). 146 */ 147 #define CRYPTO_TFM_NEED_KEY 0x00000001 148 149 #define CRYPTO_TFM_REQ_MASK 0x000fff00 150 #define CRYPTO_TFM_REQ_FORBID_WEAK_KEYS 0x00000100 151 #define CRYPTO_TFM_REQ_MAY_SLEEP 0x00000200 152 #define CRYPTO_TFM_REQ_MAY_BACKLOG 0x00000400 153 154 /* 155 * Miscellaneous stuff. 156 */ 157 #define CRYPTO_MAX_ALG_NAME 128 158 159 /* 160 * The macro CRYPTO_MINALIGN_ATTR (along with the void * type in the actual 161 * declaration) is used to ensure that the crypto_tfm context structure is 162 * aligned correctly for the given architecture so that there are no alignment 163 * faults for C data types. On architectures that support non-cache coherent 164 * DMA, such as ARM or arm64, it also takes into account the minimal alignment 165 * that is required to ensure that the context struct member does not share any 166 * cachelines with the rest of the struct. This is needed to ensure that cache 167 * maintenance for non-coherent DMA (cache invalidation in particular) does not 168 * affect data that may be accessed by the CPU concurrently. 169 */ 170 #define CRYPTO_MINALIGN ARCH_KMALLOC_MINALIGN 171 172 #define CRYPTO_MINALIGN_ATTR __attribute__ ((__aligned__(CRYPTO_MINALIGN))) 173 174 struct scatterlist; 175 struct crypto_async_request; 176 struct crypto_tfm; 177 struct crypto_type; 178 179 typedef void (*crypto_completion_t)(void *req, int err); 180 181 /** 182 * DOC: Block Cipher Context Data Structures 183 * 184 * These data structures define the operating context for each block cipher 185 * type. 186 */ 187 188 struct crypto_async_request { 189 struct list_head list; 190 crypto_completion_t complete; 191 void *data; 192 struct crypto_tfm *tfm; 193 194 u32 flags; 195 }; 196 197 /** 198 * DOC: Block Cipher Algorithm Definitions 199 * 200 * These data structures define modular crypto algorithm implementations, 201 * managed via crypto_register_alg() and crypto_unregister_alg(). 202 */ 203 204 /** 205 * struct cipher_alg - single-block symmetric ciphers definition 206 * @cia_min_keysize: Minimum key size supported by the transformation. This is 207 * the smallest key length supported by this transformation 208 * algorithm. This must be set to one of the pre-defined 209 * values as this is not hardware specific. Possible values 210 * for this field can be found via git grep "_MIN_KEY_SIZE" 211 * include/crypto/ 212 * @cia_max_keysize: Maximum key size supported by the transformation. This is 213 * the largest key length supported by this transformation 214 * algorithm. This must be set to one of the pre-defined values 215 * as this is not hardware specific. Possible values for this 216 * field can be found via git grep "_MAX_KEY_SIZE" 217 * include/crypto/ 218 * @cia_setkey: Set key for the transformation. This function is used to either 219 * program a supplied key into the hardware or store the key in the 220 * transformation context for programming it later. Note that this 221 * function does modify the transformation context. This function 222 * can be called multiple times during the existence of the 223 * transformation object, so one must make sure the key is properly 224 * reprogrammed into the hardware. This function is also 225 * responsible for checking the key length for validity. 226 * @cia_encrypt: Encrypt a single block. This function is used to encrypt a 227 * single block of data, which must be @cra_blocksize big. This 228 * always operates on a full @cra_blocksize and it is not possible 229 * to encrypt a block of smaller size. The supplied buffers must 230 * therefore also be at least of @cra_blocksize size. Both the 231 * input and output buffers are always aligned to @cra_alignmask. 232 * In case either of the input or output buffer supplied by user 233 * of the crypto API is not aligned to @cra_alignmask, the crypto 234 * API will re-align the buffers. The re-alignment means that a 235 * new buffer will be allocated, the data will be copied into the 236 * new buffer, then the processing will happen on the new buffer, 237 * then the data will be copied back into the original buffer and 238 * finally the new buffer will be freed. In case a software 239 * fallback was put in place in the @cra_init call, this function 240 * might need to use the fallback if the algorithm doesn't support 241 * all of the key sizes. In case the key was stored in 242 * transformation context, the key might need to be re-programmed 243 * into the hardware in this function. This function shall not 244 * modify the transformation context, as this function may be 245 * called in parallel with the same transformation object. 246 * @cia_decrypt: Decrypt a single block. This is a reverse counterpart to 247 * @cia_encrypt, and the conditions are exactly the same. 248 * 249 * All fields are mandatory and must be filled. 250 */ 251 struct cipher_alg { 252 unsigned int cia_min_keysize; 253 unsigned int cia_max_keysize; 254 int (*cia_setkey)(struct crypto_tfm *tfm, const u8 *key, 255 unsigned int keylen); 256 void (*cia_encrypt)(struct crypto_tfm *tfm, u8 *dst, const u8 *src); 257 void (*cia_decrypt)(struct crypto_tfm *tfm, u8 *dst, const u8 *src); 258 }; 259 260 /** 261 * struct compress_alg - compression/decompression algorithm 262 * @coa_compress: Compress a buffer of specified length, storing the resulting 263 * data in the specified buffer. Return the length of the 264 * compressed data in dlen. 265 * @coa_decompress: Decompress the source buffer, storing the uncompressed 266 * data in the specified buffer. The length of the data is 267 * returned in dlen. 268 * 269 * All fields are mandatory. 270 */ 271 struct compress_alg { 272 int (*coa_compress)(struct crypto_tfm *tfm, const u8 *src, 273 unsigned int slen, u8 *dst, unsigned int *dlen); 274 int (*coa_decompress)(struct crypto_tfm *tfm, const u8 *src, 275 unsigned int slen, u8 *dst, unsigned int *dlen); 276 }; 277 278 #define cra_cipher cra_u.cipher 279 #define cra_compress cra_u.compress 280 281 /** 282 * struct crypto_alg - definition of a cryptograpic cipher algorithm 283 * @cra_flags: Flags describing this transformation. See include/linux/crypto.h 284 * CRYPTO_ALG_* flags for the flags which go in here. Those are 285 * used for fine-tuning the description of the transformation 286 * algorithm. 287 * @cra_blocksize: Minimum block size of this transformation. The size in bytes 288 * of the smallest possible unit which can be transformed with 289 * this algorithm. The users must respect this value. 290 * In case of HASH transformation, it is possible for a smaller 291 * block than @cra_blocksize to be passed to the crypto API for 292 * transformation, in case of any other transformation type, an 293 * error will be returned upon any attempt to transform smaller 294 * than @cra_blocksize chunks. 295 * @cra_ctxsize: Size of the operational context of the transformation. This 296 * value informs the kernel crypto API about the memory size 297 * needed to be allocated for the transformation context. 298 * @cra_alignmask: Alignment mask for the input and output data buffer. The data 299 * buffer containing the input data for the algorithm must be 300 * aligned to this alignment mask. The data buffer for the 301 * output data must be aligned to this alignment mask. Note that 302 * the Crypto API will do the re-alignment in software, but 303 * only under special conditions and there is a performance hit. 304 * The re-alignment happens at these occasions for different 305 * @cra_u types: cipher -- For both input data and output data 306 * buffer; ahash -- For output hash destination buf; shash -- 307 * For output hash destination buf. 308 * This is needed on hardware which is flawed by design and 309 * cannot pick data from arbitrary addresses. 310 * @cra_priority: Priority of this transformation implementation. In case 311 * multiple transformations with same @cra_name are available to 312 * the Crypto API, the kernel will use the one with highest 313 * @cra_priority. 314 * @cra_name: Generic name (usable by multiple implementations) of the 315 * transformation algorithm. This is the name of the transformation 316 * itself. This field is used by the kernel when looking up the 317 * providers of particular transformation. 318 * @cra_driver_name: Unique name of the transformation provider. This is the 319 * name of the provider of the transformation. This can be any 320 * arbitrary value, but in the usual case, this contains the 321 * name of the chip or provider and the name of the 322 * transformation algorithm. 323 * @cra_type: Type of the cryptographic transformation. This is a pointer to 324 * struct crypto_type, which implements callbacks common for all 325 * transformation types. There are multiple options, such as 326 * &crypto_skcipher_type, &crypto_ahash_type, &crypto_rng_type. 327 * This field might be empty. In that case, there are no common 328 * callbacks. This is the case for: cipher, compress, shash. 329 * @cra_u: Callbacks implementing the transformation. This is a union of 330 * multiple structures. Depending on the type of transformation selected 331 * by @cra_type and @cra_flags above, the associated structure must be 332 * filled with callbacks. This field might be empty. This is the case 333 * for ahash, shash. 334 * @cra_init: Initialize the cryptographic transformation object. This function 335 * is used to initialize the cryptographic transformation object. 336 * This function is called only once at the instantiation time, right 337 * after the transformation context was allocated. In case the 338 * cryptographic hardware has some special requirements which need to 339 * be handled by software, this function shall check for the precise 340 * requirement of the transformation and put any software fallbacks 341 * in place. 342 * @cra_exit: Deinitialize the cryptographic transformation object. This is a 343 * counterpart to @cra_init, used to remove various changes set in 344 * @cra_init. 345 * @cra_u.cipher: Union member which contains a single-block symmetric cipher 346 * definition. See @struct @cipher_alg. 347 * @cra_u.compress: Union member which contains a (de)compression algorithm. 348 * See @struct @compress_alg. 349 * @cra_module: Owner of this transformation implementation. Set to THIS_MODULE 350 * @cra_list: internally used 351 * @cra_users: internally used 352 * @cra_refcnt: internally used 353 * @cra_destroy: internally used 354 * 355 * The struct crypto_alg describes a generic Crypto API algorithm and is common 356 * for all of the transformations. Any variable not documented here shall not 357 * be used by a cipher implementation as it is internal to the Crypto API. 358 */ 359 struct crypto_alg { 360 struct list_head cra_list; 361 struct list_head cra_users; 362 363 u32 cra_flags; 364 unsigned int cra_blocksize; 365 unsigned int cra_ctxsize; 366 unsigned int cra_alignmask; 367 368 int cra_priority; 369 refcount_t cra_refcnt; 370 371 char cra_name[CRYPTO_MAX_ALG_NAME]; 372 char cra_driver_name[CRYPTO_MAX_ALG_NAME]; 373 374 const struct crypto_type *cra_type; 375 376 union { 377 struct cipher_alg cipher; 378 struct compress_alg compress; 379 } cra_u; 380 381 int (*cra_init)(struct crypto_tfm *tfm); 382 void (*cra_exit)(struct crypto_tfm *tfm); 383 void (*cra_destroy)(struct crypto_alg *alg); 384 385 struct module *cra_module; 386 } CRYPTO_MINALIGN_ATTR; 387 388 /* 389 * A helper struct for waiting for completion of async crypto ops 390 */ 391 struct crypto_wait { 392 struct completion completion; 393 int err; 394 }; 395 396 /* 397 * Macro for declaring a crypto op async wait object on stack 398 */ 399 #define DECLARE_CRYPTO_WAIT(_wait) \ 400 struct crypto_wait _wait = { \ 401 COMPLETION_INITIALIZER_ONSTACK((_wait).completion), 0 } 402 403 /* 404 * Async ops completion helper functioons 405 */ 406 void crypto_req_done(void *req, int err); 407 408 static inline int crypto_wait_req(int err, struct crypto_wait *wait) 409 { 410 switch (err) { 411 case -EINPROGRESS: 412 case -EBUSY: 413 wait_for_completion(&wait->completion); 414 reinit_completion(&wait->completion); 415 err = wait->err; 416 break; 417 } 418 419 return err; 420 } 421 422 static inline void crypto_init_wait(struct crypto_wait *wait) 423 { 424 init_completion(&wait->completion); 425 } 426 427 /* 428 * Algorithm registration interface. 429 */ 430 int crypto_register_alg(struct crypto_alg *alg); 431 void crypto_unregister_alg(struct crypto_alg *alg); 432 int crypto_register_algs(struct crypto_alg *algs, int count); 433 void crypto_unregister_algs(struct crypto_alg *algs, int count); 434 435 /* 436 * Algorithm query interface. 437 */ 438 int crypto_has_alg(const char *name, u32 type, u32 mask); 439 440 /* 441 * Transforms: user-instantiated objects which encapsulate algorithms 442 * and core processing logic. Managed via crypto_alloc_*() and 443 * crypto_free_*(), as well as the various helpers below. 444 */ 445 446 struct crypto_tfm { 447 448 u32 crt_flags; 449 450 int node; 451 452 void (*exit)(struct crypto_tfm *tfm); 453 454 struct crypto_alg *__crt_alg; 455 456 void *__crt_ctx[] CRYPTO_MINALIGN_ATTR; 457 }; 458 459 struct crypto_comp { 460 struct crypto_tfm base; 461 }; 462 463 /* 464 * Transform user interface. 465 */ 466 467 struct crypto_tfm *crypto_alloc_base(const char *alg_name, u32 type, u32 mask); 468 void crypto_destroy_tfm(void *mem, struct crypto_tfm *tfm); 469 470 static inline void crypto_free_tfm(struct crypto_tfm *tfm) 471 { 472 return crypto_destroy_tfm(tfm, tfm); 473 } 474 475 int alg_test(const char *driver, const char *alg, u32 type, u32 mask); 476 477 /* 478 * Transform helpers which query the underlying algorithm. 479 */ 480 static inline const char *crypto_tfm_alg_name(struct crypto_tfm *tfm) 481 { 482 return tfm->__crt_alg->cra_name; 483 } 484 485 static inline const char *crypto_tfm_alg_driver_name(struct crypto_tfm *tfm) 486 { 487 return tfm->__crt_alg->cra_driver_name; 488 } 489 490 static inline int crypto_tfm_alg_priority(struct crypto_tfm *tfm) 491 { 492 return tfm->__crt_alg->cra_priority; 493 } 494 495 static inline u32 crypto_tfm_alg_type(struct crypto_tfm *tfm) 496 { 497 return tfm->__crt_alg->cra_flags & CRYPTO_ALG_TYPE_MASK; 498 } 499 500 static inline unsigned int crypto_tfm_alg_blocksize(struct crypto_tfm *tfm) 501 { 502 return tfm->__crt_alg->cra_blocksize; 503 } 504 505 static inline unsigned int crypto_tfm_alg_alignmask(struct crypto_tfm *tfm) 506 { 507 return tfm->__crt_alg->cra_alignmask; 508 } 509 510 static inline u32 crypto_tfm_get_flags(struct crypto_tfm *tfm) 511 { 512 return tfm->crt_flags; 513 } 514 515 static inline void crypto_tfm_set_flags(struct crypto_tfm *tfm, u32 flags) 516 { 517 tfm->crt_flags |= flags; 518 } 519 520 static inline void crypto_tfm_clear_flags(struct crypto_tfm *tfm, u32 flags) 521 { 522 tfm->crt_flags &= ~flags; 523 } 524 525 static inline unsigned int crypto_tfm_ctx_alignment(void) 526 { 527 struct crypto_tfm *tfm; 528 return __alignof__(tfm->__crt_ctx); 529 } 530 531 static inline struct crypto_comp *__crypto_comp_cast(struct crypto_tfm *tfm) 532 { 533 return (struct crypto_comp *)tfm; 534 } 535 536 static inline struct crypto_comp *crypto_alloc_comp(const char *alg_name, 537 u32 type, u32 mask) 538 { 539 type &= ~CRYPTO_ALG_TYPE_MASK; 540 type |= CRYPTO_ALG_TYPE_COMPRESS; 541 mask |= CRYPTO_ALG_TYPE_MASK; 542 543 return __crypto_comp_cast(crypto_alloc_base(alg_name, type, mask)); 544 } 545 546 static inline struct crypto_tfm *crypto_comp_tfm(struct crypto_comp *tfm) 547 { 548 return &tfm->base; 549 } 550 551 static inline void crypto_free_comp(struct crypto_comp *tfm) 552 { 553 crypto_free_tfm(crypto_comp_tfm(tfm)); 554 } 555 556 static inline int crypto_has_comp(const char *alg_name, u32 type, u32 mask) 557 { 558 type &= ~CRYPTO_ALG_TYPE_MASK; 559 type |= CRYPTO_ALG_TYPE_COMPRESS; 560 mask |= CRYPTO_ALG_TYPE_MASK; 561 562 return crypto_has_alg(alg_name, type, mask); 563 } 564 565 static inline const char *crypto_comp_name(struct crypto_comp *tfm) 566 { 567 return crypto_tfm_alg_name(crypto_comp_tfm(tfm)); 568 } 569 570 int crypto_comp_compress(struct crypto_comp *tfm, 571 const u8 *src, unsigned int slen, 572 u8 *dst, unsigned int *dlen); 573 574 int crypto_comp_decompress(struct crypto_comp *tfm, 575 const u8 *src, unsigned int slen, 576 u8 *dst, unsigned int *dlen); 577 578 #endif /* _LINUX_CRYPTO_H */ 579 580