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