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 
crypto_wait_req(int err,struct crypto_wait * wait)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 
crypto_init_wait(struct crypto_wait * wait)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 
crypto_free_tfm(struct crypto_tfm * tfm)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  */
crypto_tfm_alg_name(struct crypto_tfm * tfm)455 static inline const char *crypto_tfm_alg_name(struct crypto_tfm *tfm)
456 {
457 	return tfm->__crt_alg->cra_name;
458 }
459 
crypto_tfm_alg_driver_name(struct crypto_tfm * tfm)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 
crypto_tfm_alg_blocksize(struct crypto_tfm * tfm)465 static inline unsigned int crypto_tfm_alg_blocksize(struct crypto_tfm *tfm)
466 {
467 	return tfm->__crt_alg->cra_blocksize;
468 }
469 
crypto_tfm_alg_alignmask(struct crypto_tfm * tfm)470 static inline unsigned int crypto_tfm_alg_alignmask(struct crypto_tfm *tfm)
471 {
472 	return tfm->__crt_alg->cra_alignmask;
473 }
474 
crypto_tfm_get_flags(struct crypto_tfm * tfm)475 static inline u32 crypto_tfm_get_flags(struct crypto_tfm *tfm)
476 {
477 	return tfm->crt_flags;
478 }
479 
crypto_tfm_set_flags(struct crypto_tfm * tfm,u32 flags)480 static inline void crypto_tfm_set_flags(struct crypto_tfm *tfm, u32 flags)
481 {
482 	tfm->crt_flags |= flags;
483 }
484 
crypto_tfm_clear_flags(struct crypto_tfm * tfm,u32 flags)485 static inline void crypto_tfm_clear_flags(struct crypto_tfm *tfm, u32 flags)
486 {
487 	tfm->crt_flags &= ~flags;
488 }
489 
crypto_tfm_ctx_alignment(void)490 static inline unsigned int crypto_tfm_ctx_alignment(void)
491 {
492 	struct crypto_tfm *tfm;
493 	return __alignof__(tfm->__crt_ctx);
494 }
495 
__crypto_comp_cast(struct crypto_tfm * tfm)496 static inline struct crypto_comp *__crypto_comp_cast(struct crypto_tfm *tfm)
497 {
498 	return (struct crypto_comp *)tfm;
499 }
500 
crypto_alloc_comp(const char * alg_name,u32 type,u32 mask)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 
crypto_comp_tfm(struct crypto_comp * tfm)511 static inline struct crypto_tfm *crypto_comp_tfm(struct crypto_comp *tfm)
512 {
513 	return &tfm->base;
514 }
515 
crypto_free_comp(struct crypto_comp * tfm)516 static inline void crypto_free_comp(struct crypto_comp *tfm)
517 {
518 	crypto_free_tfm(crypto_comp_tfm(tfm));
519 }
520 
crypto_has_comp(const char * alg_name,u32 type,u32 mask)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 
crypto_comp_name(struct crypto_comp * tfm)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