Line data Source code
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/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_AKCIPHER 0x00000006
29 : #define CRYPTO_ALG_TYPE_SIG 0x00000007
30 : #define CRYPTO_ALG_TYPE_KPP 0x00000008
31 : #define CRYPTO_ALG_TYPE_ACOMPRESS 0x0000000a
32 : #define CRYPTO_ALG_TYPE_SCOMPRESS 0x0000000b
33 : #define CRYPTO_ALG_TYPE_RNG 0x0000000c
34 : #define CRYPTO_ALG_TYPE_HASH 0x0000000e
35 : #define CRYPTO_ALG_TYPE_SHASH 0x0000000e
36 : #define CRYPTO_ALG_TYPE_AHASH 0x0000000f
37 :
38 : #define CRYPTO_ALG_TYPE_HASH_MASK 0x0000000e
39 : #define CRYPTO_ALG_TYPE_AHASH_MASK 0x0000000e
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 : * - The result buffer must be aligned to the algorithm's alignmask.
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 : /*
130 : * Transform masks and values (for crt_flags).
131 : */
132 : #define CRYPTO_TFM_NEED_KEY 0x00000001
133 :
134 : #define CRYPTO_TFM_REQ_MASK 0x000fff00
135 : #define CRYPTO_TFM_REQ_FORBID_WEAK_KEYS 0x00000100
136 : #define CRYPTO_TFM_REQ_MAY_SLEEP 0x00000200
137 : #define CRYPTO_TFM_REQ_MAY_BACKLOG 0x00000400
138 :
139 : /*
140 : * Miscellaneous stuff.
141 : */
142 : #define CRYPTO_MAX_ALG_NAME 128
143 :
144 : /*
145 : * The macro CRYPTO_MINALIGN_ATTR (along with the void * type in the actual
146 : * declaration) is used to ensure that the crypto_tfm context structure is
147 : * aligned correctly for the given architecture so that there are no alignment
148 : * faults for C data types. On architectures that support non-cache coherent
149 : * DMA, such as ARM or arm64, it also takes into account the minimal alignment
150 : * that is required to ensure that the context struct member does not share any
151 : * cachelines with the rest of the struct. This is needed to ensure that cache
152 : * maintenance for non-coherent DMA (cache invalidation in particular) does not
153 : * affect data that may be accessed by the CPU concurrently.
154 : */
155 : #define CRYPTO_MINALIGN ARCH_KMALLOC_MINALIGN
156 :
157 : #define CRYPTO_MINALIGN_ATTR __attribute__ ((__aligned__(CRYPTO_MINALIGN)))
158 :
159 : struct crypto_tfm;
160 : struct crypto_type;
161 : struct module;
162 :
163 : typedef void (*crypto_completion_t)(void *req, int err);
164 :
165 : /**
166 : * DOC: Block Cipher Context Data Structures
167 : *
168 : * These data structures define the operating context for each block cipher
169 : * type.
170 : */
171 :
172 : struct crypto_async_request {
173 : struct list_head list;
174 : crypto_completion_t complete;
175 : void *data;
176 : struct crypto_tfm *tfm;
177 :
178 : u32 flags;
179 : };
180 :
181 : /**
182 : * DOC: Block Cipher Algorithm Definitions
183 : *
184 : * These data structures define modular crypto algorithm implementations,
185 : * managed via crypto_register_alg() and crypto_unregister_alg().
186 : */
187 :
188 : /**
189 : * struct cipher_alg - single-block symmetric ciphers definition
190 : * @cia_min_keysize: Minimum key size supported by the transformation. This is
191 : * the smallest key length supported by this transformation
192 : * algorithm. This must be set to one of the pre-defined
193 : * values as this is not hardware specific. Possible values
194 : * for this field can be found via git grep "_MIN_KEY_SIZE"
195 : * include/crypto/
196 : * @cia_max_keysize: Maximum key size supported by the transformation. This is
197 : * the largest key length supported by this transformation
198 : * algorithm. This must be set to one of the pre-defined values
199 : * as this is not hardware specific. Possible values for this
200 : * field can be found via git grep "_MAX_KEY_SIZE"
201 : * include/crypto/
202 : * @cia_setkey: Set key for the transformation. This function is used to either
203 : * program a supplied key into the hardware or store the key in the
204 : * transformation context for programming it later. Note that this
205 : * function does modify the transformation context. This function
206 : * can be called multiple times during the existence of the
207 : * transformation object, so one must make sure the key is properly
208 : * reprogrammed into the hardware. This function is also
209 : * responsible for checking the key length for validity.
210 : * @cia_encrypt: Encrypt a single block. This function is used to encrypt a
211 : * single block of data, which must be @cra_blocksize big. This
212 : * always operates on a full @cra_blocksize and it is not possible
213 : * to encrypt a block of smaller size. The supplied buffers must
214 : * therefore also be at least of @cra_blocksize size. Both the
215 : * input and output buffers are always aligned to @cra_alignmask.
216 : * In case either of the input or output buffer supplied by user
217 : * of the crypto API is not aligned to @cra_alignmask, the crypto
218 : * API will re-align the buffers. The re-alignment means that a
219 : * new buffer will be allocated, the data will be copied into the
220 : * new buffer, then the processing will happen on the new buffer,
221 : * then the data will be copied back into the original buffer and
222 : * finally the new buffer will be freed. In case a software
223 : * fallback was put in place in the @cra_init call, this function
224 : * might need to use the fallback if the algorithm doesn't support
225 : * all of the key sizes. In case the key was stored in
226 : * transformation context, the key might need to be re-programmed
227 : * into the hardware in this function. This function shall not
228 : * modify the transformation context, as this function may be
229 : * called in parallel with the same transformation object.
230 : * @cia_decrypt: Decrypt a single block. This is a reverse counterpart to
231 : * @cia_encrypt, and the conditions are exactly the same.
232 : *
233 : * All fields are mandatory and must be filled.
234 : */
235 : struct cipher_alg {
236 : unsigned int cia_min_keysize;
237 : unsigned int cia_max_keysize;
238 : int (*cia_setkey)(struct crypto_tfm *tfm, const u8 *key,
239 : unsigned int keylen);
240 : void (*cia_encrypt)(struct crypto_tfm *tfm, u8 *dst, const u8 *src);
241 : void (*cia_decrypt)(struct crypto_tfm *tfm, u8 *dst, const u8 *src);
242 : };
243 :
244 : /**
245 : * struct compress_alg - compression/decompression algorithm
246 : * @coa_compress: Compress a buffer of specified length, storing the resulting
247 : * data in the specified buffer. Return the length of the
248 : * compressed data in dlen.
249 : * @coa_decompress: Decompress the source buffer, storing the uncompressed
250 : * data in the specified buffer. The length of the data is
251 : * returned in dlen.
252 : *
253 : * All fields are mandatory.
254 : */
255 : struct compress_alg {
256 : int (*coa_compress)(struct crypto_tfm *tfm, const u8 *src,
257 : unsigned int slen, u8 *dst, unsigned int *dlen);
258 : int (*coa_decompress)(struct crypto_tfm *tfm, const u8 *src,
259 : unsigned int slen, u8 *dst, unsigned int *dlen);
260 : };
261 :
262 : #define cra_cipher cra_u.cipher
263 : #define cra_compress cra_u.compress
264 :
265 : /**
266 : * struct crypto_alg - definition of a cryptograpic cipher algorithm
267 : * @cra_flags: Flags describing this transformation. See include/linux/crypto.h
268 : * CRYPTO_ALG_* flags for the flags which go in here. Those are
269 : * used for fine-tuning the description of the transformation
270 : * algorithm.
271 : * @cra_blocksize: Minimum block size of this transformation. The size in bytes
272 : * of the smallest possible unit which can be transformed with
273 : * this algorithm. The users must respect this value.
274 : * In case of HASH transformation, it is possible for a smaller
275 : * block than @cra_blocksize to be passed to the crypto API for
276 : * transformation, in case of any other transformation type, an
277 : * error will be returned upon any attempt to transform smaller
278 : * than @cra_blocksize chunks.
279 : * @cra_ctxsize: Size of the operational context of the transformation. This
280 : * value informs the kernel crypto API about the memory size
281 : * needed to be allocated for the transformation context.
282 : * @cra_alignmask: Alignment mask for the input and output data buffer. The data
283 : * buffer containing the input data for the algorithm must be
284 : * aligned to this alignment mask. The data buffer for the
285 : * output data must be aligned to this alignment mask. Note that
286 : * the Crypto API will do the re-alignment in software, but
287 : * only under special conditions and there is a performance hit.
288 : * The re-alignment happens at these occasions for different
289 : * @cra_u types: cipher -- For both input data and output data
290 : * buffer; ahash -- For output hash destination buf; shash --
291 : * For output hash destination buf.
292 : * This is needed on hardware which is flawed by design and
293 : * cannot pick data from arbitrary addresses.
294 : * @cra_priority: Priority of this transformation implementation. In case
295 : * multiple transformations with same @cra_name are available to
296 : * the Crypto API, the kernel will use the one with highest
297 : * @cra_priority.
298 : * @cra_name: Generic name (usable by multiple implementations) of the
299 : * transformation algorithm. This is the name of the transformation
300 : * itself. This field is used by the kernel when looking up the
301 : * providers of particular transformation.
302 : * @cra_driver_name: Unique name of the transformation provider. This is the
303 : * name of the provider of the transformation. This can be any
304 : * arbitrary value, but in the usual case, this contains the
305 : * name of the chip or provider and the name of the
306 : * transformation algorithm.
307 : * @cra_type: Type of the cryptographic transformation. This is a pointer to
308 : * struct crypto_type, which implements callbacks common for all
309 : * transformation types. There are multiple options, such as
310 : * &crypto_skcipher_type, &crypto_ahash_type, &crypto_rng_type.
311 : * This field might be empty. In that case, there are no common
312 : * callbacks. This is the case for: cipher, compress, shash.
313 : * @cra_u: Callbacks implementing the transformation. This is a union of
314 : * multiple structures. Depending on the type of transformation selected
315 : * by @cra_type and @cra_flags above, the associated structure must be
316 : * filled with callbacks. This field might be empty. This is the case
317 : * for ahash, shash.
318 : * @cra_init: Initialize the cryptographic transformation object. This function
319 : * is used to initialize the cryptographic transformation object.
320 : * This function is called only once at the instantiation time, right
321 : * after the transformation context was allocated. In case the
322 : * cryptographic hardware has some special requirements which need to
323 : * be handled by software, this function shall check for the precise
324 : * requirement of the transformation and put any software fallbacks
325 : * in place.
326 : * @cra_exit: Deinitialize the cryptographic transformation object. This is a
327 : * counterpart to @cra_init, used to remove various changes set in
328 : * @cra_init.
329 : * @cra_u.cipher: Union member which contains a single-block symmetric cipher
330 : * definition. See @struct @cipher_alg.
331 : * @cra_u.compress: Union member which contains a (de)compression algorithm.
332 : * See @struct @compress_alg.
333 : * @cra_module: Owner of this transformation implementation. Set to THIS_MODULE
334 : * @cra_list: internally used
335 : * @cra_users: internally used
336 : * @cra_refcnt: internally used
337 : * @cra_destroy: internally used
338 : *
339 : * The struct crypto_alg describes a generic Crypto API algorithm and is common
340 : * for all of the transformations. Any variable not documented here shall not
341 : * be used by a cipher implementation as it is internal to the Crypto API.
342 : */
343 : struct crypto_alg {
344 : struct list_head cra_list;
345 : struct list_head cra_users;
346 :
347 : u32 cra_flags;
348 : unsigned int cra_blocksize;
349 : unsigned int cra_ctxsize;
350 : unsigned int cra_alignmask;
351 :
352 : int cra_priority;
353 : refcount_t cra_refcnt;
354 :
355 : char cra_name[CRYPTO_MAX_ALG_NAME];
356 : char cra_driver_name[CRYPTO_MAX_ALG_NAME];
357 :
358 : const struct crypto_type *cra_type;
359 :
360 : union {
361 : struct cipher_alg cipher;
362 : struct compress_alg compress;
363 : } cra_u;
364 :
365 : int (*cra_init)(struct crypto_tfm *tfm);
366 : void (*cra_exit)(struct crypto_tfm *tfm);
367 : void (*cra_destroy)(struct crypto_alg *alg);
368 :
369 : struct module *cra_module;
370 : } CRYPTO_MINALIGN_ATTR;
371 :
372 : /*
373 : * A helper struct for waiting for completion of async crypto ops
374 : */
375 : struct crypto_wait {
376 : struct completion completion;
377 : int err;
378 : };
379 :
380 : /*
381 : * Macro for declaring a crypto op async wait object on stack
382 : */
383 : #define DECLARE_CRYPTO_WAIT(_wait) \
384 : struct crypto_wait _wait = { \
385 : COMPLETION_INITIALIZER_ONSTACK((_wait).completion), 0 }
386 :
387 : /*
388 : * Async ops completion helper functioons
389 : */
390 : void crypto_req_done(void *req, int err);
391 :
392 : static inline int crypto_wait_req(int err, struct crypto_wait *wait)
393 : {
394 : switch (err) {
395 : case -EINPROGRESS:
396 : case -EBUSY:
397 : wait_for_completion(&wait->completion);
398 : reinit_completion(&wait->completion);
399 : err = wait->err;
400 : break;
401 : }
402 :
403 : return err;
404 : }
405 :
406 : static inline void crypto_init_wait(struct crypto_wait *wait)
407 : {
408 : init_completion(&wait->completion);
409 : }
410 :
411 : /*
412 : * Algorithm query interface.
413 : */
414 : int crypto_has_alg(const char *name, u32 type, u32 mask);
415 :
416 : /*
417 : * Transforms: user-instantiated objects which encapsulate algorithms
418 : * and core processing logic. Managed via crypto_alloc_*() and
419 : * crypto_free_*(), as well as the various helpers below.
420 : */
421 :
422 : struct crypto_tfm {
423 : refcount_t refcnt;
424 :
425 : u32 crt_flags;
426 :
427 : int node;
428 :
429 : void (*exit)(struct crypto_tfm *tfm);
430 :
431 : struct crypto_alg *__crt_alg;
432 :
433 : void *__crt_ctx[] CRYPTO_MINALIGN_ATTR;
434 : };
435 :
436 : struct crypto_comp {
437 : struct crypto_tfm base;
438 : };
439 :
440 : /*
441 : * Transform user interface.
442 : */
443 :
444 : struct crypto_tfm *crypto_alloc_base(const char *alg_name, u32 type, u32 mask);
445 : void crypto_destroy_tfm(void *mem, struct crypto_tfm *tfm);
446 :
447 : static inline void crypto_free_tfm(struct crypto_tfm *tfm)
448 : {
449 : return crypto_destroy_tfm(tfm, tfm);
450 : }
451 :
452 : /*
453 : * Transform helpers which query the underlying algorithm.
454 : */
455 : static inline const char *crypto_tfm_alg_name(struct crypto_tfm *tfm)
456 : {
457 : return tfm->__crt_alg->cra_name;
458 : }
459 :
460 : static inline const char *crypto_tfm_alg_driver_name(struct crypto_tfm *tfm)
461 : {
462 0 : return tfm->__crt_alg->cra_driver_name;
463 : }
464 :
465 : static inline unsigned int crypto_tfm_alg_blocksize(struct crypto_tfm *tfm)
466 : {
467 : return tfm->__crt_alg->cra_blocksize;
468 : }
469 :
470 : static inline unsigned int crypto_tfm_alg_alignmask(struct crypto_tfm *tfm)
471 : {
472 : return tfm->__crt_alg->cra_alignmask;
473 : }
474 :
475 : static inline u32 crypto_tfm_get_flags(struct crypto_tfm *tfm)
476 : {
477 0 : return tfm->crt_flags;
478 : }
479 :
480 : static inline void crypto_tfm_set_flags(struct crypto_tfm *tfm, u32 flags)
481 : {
482 : tfm->crt_flags |= flags;
483 : }
484 :
485 : static inline void crypto_tfm_clear_flags(struct crypto_tfm *tfm, u32 flags)
486 : {
487 : tfm->crt_flags &= ~flags;
488 : }
489 :
490 : static inline unsigned int crypto_tfm_ctx_alignment(void)
491 : {
492 : struct crypto_tfm *tfm;
493 : return __alignof__(tfm->__crt_ctx);
494 : }
495 :
496 : static inline struct crypto_comp *__crypto_comp_cast(struct crypto_tfm *tfm)
497 : {
498 : return (struct crypto_comp *)tfm;
499 : }
500 :
501 : static inline struct crypto_comp *crypto_alloc_comp(const char *alg_name,
502 : u32 type, u32 mask)
503 : {
504 : type &= ~CRYPTO_ALG_TYPE_MASK;
505 : type |= CRYPTO_ALG_TYPE_COMPRESS;
506 : mask |= CRYPTO_ALG_TYPE_MASK;
507 :
508 : return __crypto_comp_cast(crypto_alloc_base(alg_name, type, mask));
509 : }
510 :
511 : static inline struct crypto_tfm *crypto_comp_tfm(struct crypto_comp *tfm)
512 : {
513 : return &tfm->base;
514 : }
515 :
516 : static inline void crypto_free_comp(struct crypto_comp *tfm)
517 : {
518 : crypto_free_tfm(crypto_comp_tfm(tfm));
519 : }
520 :
521 : static inline int crypto_has_comp(const char *alg_name, u32 type, u32 mask)
522 : {
523 : type &= ~CRYPTO_ALG_TYPE_MASK;
524 : type |= CRYPTO_ALG_TYPE_COMPRESS;
525 : mask |= CRYPTO_ALG_TYPE_MASK;
526 :
527 : return crypto_has_alg(alg_name, type, mask);
528 : }
529 :
530 : static inline const char *crypto_comp_name(struct crypto_comp *tfm)
531 : {
532 : return crypto_tfm_alg_name(crypto_comp_tfm(tfm));
533 : }
534 :
535 : int crypto_comp_compress(struct crypto_comp *tfm,
536 : const u8 *src, unsigned int slen,
537 : u8 *dst, unsigned int *dlen);
538 :
539 : int crypto_comp_decompress(struct crypto_comp *tfm,
540 : const u8 *src, unsigned int slen,
541 : u8 *dst, unsigned int *dlen);
542 :
543 : #endif /* _LINUX_CRYPTO_H */
544 :
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