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_LSKCIPHER 0x00000004
28 #define CRYPTO_ALG_TYPE_SKCIPHER 0x00000005
29 #define CRYPTO_ALG_TYPE_AKCIPHER 0x00000006
30 #define CRYPTO_ALG_TYPE_SIG 0x00000007
31 #define CRYPTO_ALG_TYPE_KPP 0x00000008
32 #define CRYPTO_ALG_TYPE_ACOMPRESS 0x0000000a
33 #define CRYPTO_ALG_TYPE_SCOMPRESS 0x0000000b
34 #define CRYPTO_ALG_TYPE_RNG 0x0000000c
35 #define CRYPTO_ALG_TYPE_HASH 0x0000000e
36 #define CRYPTO_ALG_TYPE_SHASH 0x0000000e
37 #define CRYPTO_ALG_TYPE_AHASH 0x0000000f
38
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 * - crypto_ahash_finup() must not be used unless the algorithm implements
114 * ->finup() natively.
115 */
116 #define CRYPTO_ALG_ALLOCATES_MEMORY 0x00010000
117
118 /*
119 * Mark an algorithm as a service implementation only usable by a
120 * template and never by a normal user of the kernel crypto API.
121 * This is intended to be used by algorithms that are themselves
122 * not FIPS-approved but may instead be used to implement parts of
123 * a FIPS-approved algorithm (e.g., dh vs. ffdhe2048(dh)).
124 */
125 #define CRYPTO_ALG_FIPS_INTERNAL 0x00020000
126
127 /*
128 * Transform masks and values (for crt_flags).
129 */
130 #define CRYPTO_TFM_NEED_KEY 0x00000001
131
132 #define CRYPTO_TFM_REQ_MASK 0x000fff00
133 #define CRYPTO_TFM_REQ_FORBID_WEAK_KEYS 0x00000100
134 #define CRYPTO_TFM_REQ_MAY_SLEEP 0x00000200
135 #define CRYPTO_TFM_REQ_MAY_BACKLOG 0x00000400
136
137 /*
138 * Miscellaneous stuff.
139 */
140 #define CRYPTO_MAX_ALG_NAME 128
141
142 /*
143 * The macro CRYPTO_MINALIGN_ATTR (along with the void * type in the actual
144 * declaration) is used to ensure that the crypto_tfm context structure is
145 * aligned correctly for the given architecture so that there are no alignment
146 * faults for C data types. On architectures that support non-cache coherent
147 * DMA, such as ARM or arm64, it also takes into account the minimal alignment
148 * that is required to ensure that the context struct member does not share any
149 * cachelines with the rest of the struct. This is needed to ensure that cache
150 * maintenance for non-coherent DMA (cache invalidation in particular) does not
151 * affect data that may be accessed by the CPU concurrently.
152 */
153 #define CRYPTO_MINALIGN ARCH_KMALLOC_MINALIGN
154
155 #define CRYPTO_MINALIGN_ATTR __attribute__ ((__aligned__(CRYPTO_MINALIGN)))
156
157 struct crypto_tfm;
158 struct crypto_type;
159 struct module;
160
161 typedef void (*crypto_completion_t)(void *req, int err);
162
163 /**
164 * DOC: Block Cipher Context Data Structures
165 *
166 * These data structures define the operating context for each block cipher
167 * type.
168 */
169
170 struct crypto_async_request {
171 struct list_head list;
172 crypto_completion_t complete;
173 void *data;
174 struct crypto_tfm *tfm;
175
176 u32 flags;
177 };
178
179 /**
180 * DOC: Block Cipher Algorithm Definitions
181 *
182 * These data structures define modular crypto algorithm implementations,
183 * managed via crypto_register_alg() and crypto_unregister_alg().
184 */
185
186 /**
187 * struct cipher_alg - single-block symmetric ciphers definition
188 * @cia_min_keysize: Minimum key size supported by the transformation. This is
189 * the smallest key length supported by this transformation
190 * algorithm. This must be set to one of the pre-defined
191 * values as this is not hardware specific. Possible values
192 * for this field can be found via git grep "_MIN_KEY_SIZE"
193 * include/crypto/
194 * @cia_max_keysize: Maximum key size supported by the transformation. This is
195 * the largest key length supported by this transformation
196 * algorithm. This must be set to one of the pre-defined values
197 * as this is not hardware specific. Possible values for this
198 * field can be found via git grep "_MAX_KEY_SIZE"
199 * include/crypto/
200 * @cia_setkey: Set key for the transformation. This function is used to either
201 * program a supplied key into the hardware or store the key in the
202 * transformation context for programming it later. Note that this
203 * function does modify the transformation context. This function
204 * can be called multiple times during the existence of the
205 * transformation object, so one must make sure the key is properly
206 * reprogrammed into the hardware. This function is also
207 * responsible for checking the key length for validity.
208 * @cia_encrypt: Encrypt a single block. This function is used to encrypt a
209 * single block of data, which must be @cra_blocksize big. This
210 * always operates on a full @cra_blocksize and it is not possible
211 * to encrypt a block of smaller size. The supplied buffers must
212 * therefore also be at least of @cra_blocksize size. Both the
213 * input and output buffers are always aligned to @cra_alignmask.
214 * In case either of the input or output buffer supplied by user
215 * of the crypto API is not aligned to @cra_alignmask, the crypto
216 * API will re-align the buffers. The re-alignment means that a
217 * new buffer will be allocated, the data will be copied into the
218 * new buffer, then the processing will happen on the new buffer,
219 * then the data will be copied back into the original buffer and
220 * finally the new buffer will be freed. In case a software
221 * fallback was put in place in the @cra_init call, this function
222 * might need to use the fallback if the algorithm doesn't support
223 * all of the key sizes. In case the key was stored in
224 * transformation context, the key might need to be re-programmed
225 * into the hardware in this function. This function shall not
226 * modify the transformation context, as this function may be
227 * called in parallel with the same transformation object.
228 * @cia_decrypt: Decrypt a single block. This is a reverse counterpart to
229 * @cia_encrypt, and the conditions are exactly the same.
230 *
231 * All fields are mandatory and must be filled.
232 */
233 struct cipher_alg {
234 unsigned int cia_min_keysize;
235 unsigned int cia_max_keysize;
236 int (*cia_setkey)(struct crypto_tfm *tfm, const u8 *key,
237 unsigned int keylen);
238 void (*cia_encrypt)(struct crypto_tfm *tfm, u8 *dst, const u8 *src);
239 void (*cia_decrypt)(struct crypto_tfm *tfm, u8 *dst, const u8 *src);
240 };
241
242 /**
243 * struct compress_alg - compression/decompression algorithm
244 * @coa_compress: Compress a buffer of specified length, storing the resulting
245 * data in the specified buffer. Return the length of the
246 * compressed data in dlen.
247 * @coa_decompress: Decompress the source buffer, storing the uncompressed
248 * data in the specified buffer. The length of the data is
249 * returned in dlen.
250 *
251 * All fields are mandatory.
252 */
253 struct compress_alg {
254 int (*coa_compress)(struct crypto_tfm *tfm, const u8 *src,
255 unsigned int slen, u8 *dst, unsigned int *dlen);
256 int (*coa_decompress)(struct crypto_tfm *tfm, const u8 *src,
257 unsigned int slen, u8 *dst, unsigned int *dlen);
258 };
259
260 #define cra_cipher cra_u.cipher
261 #define cra_compress cra_u.compress
262
263 /**
264 * struct crypto_alg - definition of a cryptograpic cipher algorithm
265 * @cra_flags: Flags describing this transformation. See include/linux/crypto.h
266 * CRYPTO_ALG_* flags for the flags which go in here. Those are
267 * used for fine-tuning the description of the transformation
268 * algorithm.
269 * @cra_blocksize: Minimum block size of this transformation. The size in bytes
270 * of the smallest possible unit which can be transformed with
271 * this algorithm. The users must respect this value.
272 * In case of HASH transformation, it is possible for a smaller
273 * block than @cra_blocksize to be passed to the crypto API for
274 * transformation, in case of any other transformation type, an
275 * error will be returned upon any attempt to transform smaller
276 * than @cra_blocksize chunks.
277 * @cra_ctxsize: Size of the operational context of the transformation. This
278 * value informs the kernel crypto API about the memory size
279 * needed to be allocated for the transformation context.
280 * @cra_alignmask: For cipher, skcipher, lskcipher, and aead algorithms this is
281 * 1 less than the alignment, in bytes, that the algorithm
282 * implementation requires for input and output buffers. When
283 * the crypto API is invoked with buffers that are not aligned
284 * to this alignment, the crypto API automatically utilizes
285 * appropriately aligned temporary buffers to comply with what
286 * the algorithm needs. (For scatterlists this happens only if
287 * the algorithm uses the skcipher_walk helper functions.) This
288 * misalignment handling carries a performance penalty, so it is
289 * preferred that algorithms do not set a nonzero alignmask.
290 * Also, crypto API users may wish to allocate buffers aligned
291 * to the alignmask of the algorithm being used, in order to
292 * avoid the API having to realign them. Note: the alignmask is
293 * not supported for hash algorithms and is always 0 for them.
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 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 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
545
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