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