xref: /freebsd/contrib/wpa/src/crypto/crypto.h (revision 63a938566d524836885917d95bd491aa4400b181)
1 /*
2  * Wrapper functions for crypto libraries
3  * Copyright (c) 2004-2013, Jouni Malinen <j@w1.fi>
4  *
5  * This software may be distributed under the terms of the BSD license.
6  * See README for more details.
7  *
8  * This file defines the cryptographic functions that need to be implemented
9  * for wpa_supplicant and hostapd. When TLS is not used, internal
10  * implementation of MD5, SHA1, and AES is used and no external libraries are
11  * required. When TLS is enabled (e.g., by enabling EAP-TLS or EAP-PEAP), the
12  * crypto library used by the TLS implementation is expected to be used for
13  * non-TLS needs, too, in order to save space by not implementing these
14  * functions twice.
15  *
16  * Wrapper code for using each crypto library is in its own file (crypto*.c)
17  * and one of these files is build and linked in to provide the functions
18  * defined here.
19  */
20 
21 #ifndef CRYPTO_H
22 #define CRYPTO_H
23 
24 /**
25  * md4_vector - MD4 hash for data vector
26  * @num_elem: Number of elements in the data vector
27  * @addr: Pointers to the data areas
28  * @len: Lengths of the data blocks
29  * @mac: Buffer for the hash
30  * Returns: 0 on success, -1 on failure
31  */
32 int md4_vector(size_t num_elem, const u8 *addr[], const size_t *len, u8 *mac);
33 
34 /**
35  * md5_vector - MD5 hash for data vector
36  * @num_elem: Number of elements in the data vector
37  * @addr: Pointers to the data areas
38  * @len: Lengths of the data blocks
39  * @mac: Buffer for the hash
40  * Returns: 0 on success, -1 on failure
41  */
42 int md5_vector(size_t num_elem, const u8 *addr[], const size_t *len, u8 *mac);
43 
44 
45 /**
46  * sha1_vector - SHA-1 hash for data vector
47  * @num_elem: Number of elements in the data vector
48  * @addr: Pointers to the data areas
49  * @len: Lengths of the data blocks
50  * @mac: Buffer for the hash
51  * Returns: 0 on success, -1 on failure
52  */
53 int sha1_vector(size_t num_elem, const u8 *addr[], const size_t *len,
54 		u8 *mac);
55 
56 /**
57  * fips186_2-prf - NIST FIPS Publication 186-2 change notice 1 PRF
58  * @seed: Seed/key for the PRF
59  * @seed_len: Seed length in bytes
60  * @x: Buffer for PRF output
61  * @xlen: Output length in bytes
62  * Returns: 0 on success, -1 on failure
63  *
64  * This function implements random number generation specified in NIST FIPS
65  * Publication 186-2 for EAP-SIM. This PRF uses a function that is similar to
66  * SHA-1, but has different message padding.
67  */
68 int __must_check fips186_2_prf(const u8 *seed, size_t seed_len, u8 *x,
69 			       size_t xlen);
70 
71 /**
72  * sha256_vector - SHA256 hash for data vector
73  * @num_elem: Number of elements in the data vector
74  * @addr: Pointers to the data areas
75  * @len: Lengths of the data blocks
76  * @mac: Buffer for the hash
77  * Returns: 0 on success, -1 on failure
78  */
79 int sha256_vector(size_t num_elem, const u8 *addr[], const size_t *len,
80 		  u8 *mac);
81 
82 /**
83  * des_encrypt - Encrypt one block with DES
84  * @clear: 8 octets (in)
85  * @key: 7 octets (in) (no parity bits included)
86  * @cypher: 8 octets (out)
87  */
88 void des_encrypt(const u8 *clear, const u8 *key, u8 *cypher);
89 
90 /**
91  * aes_encrypt_init - Initialize AES for encryption
92  * @key: Encryption key
93  * @len: Key length in bytes (usually 16, i.e., 128 bits)
94  * Returns: Pointer to context data or %NULL on failure
95  */
96 void * aes_encrypt_init(const u8 *key, size_t len);
97 
98 /**
99  * aes_encrypt - Encrypt one AES block
100  * @ctx: Context pointer from aes_encrypt_init()
101  * @plain: Plaintext data to be encrypted (16 bytes)
102  * @crypt: Buffer for the encrypted data (16 bytes)
103  */
104 void aes_encrypt(void *ctx, const u8 *plain, u8 *crypt);
105 
106 /**
107  * aes_encrypt_deinit - Deinitialize AES encryption
108  * @ctx: Context pointer from aes_encrypt_init()
109  */
110 void aes_encrypt_deinit(void *ctx);
111 
112 /**
113  * aes_decrypt_init - Initialize AES for decryption
114  * @key: Decryption key
115  * @len: Key length in bytes (usually 16, i.e., 128 bits)
116  * Returns: Pointer to context data or %NULL on failure
117  */
118 void * aes_decrypt_init(const u8 *key, size_t len);
119 
120 /**
121  * aes_decrypt - Decrypt one AES block
122  * @ctx: Context pointer from aes_encrypt_init()
123  * @crypt: Encrypted data (16 bytes)
124  * @plain: Buffer for the decrypted data (16 bytes)
125  */
126 void aes_decrypt(void *ctx, const u8 *crypt, u8 *plain);
127 
128 /**
129  * aes_decrypt_deinit - Deinitialize AES decryption
130  * @ctx: Context pointer from aes_encrypt_init()
131  */
132 void aes_decrypt_deinit(void *ctx);
133 
134 
135 enum crypto_hash_alg {
136 	CRYPTO_HASH_ALG_MD5, CRYPTO_HASH_ALG_SHA1,
137 	CRYPTO_HASH_ALG_HMAC_MD5, CRYPTO_HASH_ALG_HMAC_SHA1,
138 	CRYPTO_HASH_ALG_SHA256, CRYPTO_HASH_ALG_HMAC_SHA256
139 };
140 
141 struct crypto_hash;
142 
143 /**
144  * crypto_hash_init - Initialize hash/HMAC function
145  * @alg: Hash algorithm
146  * @key: Key for keyed hash (e.g., HMAC) or %NULL if not needed
147  * @key_len: Length of the key in bytes
148  * Returns: Pointer to hash context to use with other hash functions or %NULL
149  * on failure
150  *
151  * This function is only used with internal TLSv1 implementation
152  * (CONFIG_TLS=internal). If that is not used, the crypto wrapper does not need
153  * to implement this.
154  */
155 struct crypto_hash * crypto_hash_init(enum crypto_hash_alg alg, const u8 *key,
156 				      size_t key_len);
157 
158 /**
159  * crypto_hash_update - Add data to hash calculation
160  * @ctx: Context pointer from crypto_hash_init()
161  * @data: Data buffer to add
162  * @len: Length of the buffer
163  *
164  * This function is only used with internal TLSv1 implementation
165  * (CONFIG_TLS=internal). If that is not used, the crypto wrapper does not need
166  * to implement this.
167  */
168 void crypto_hash_update(struct crypto_hash *ctx, const u8 *data, size_t len);
169 
170 /**
171  * crypto_hash_finish - Complete hash calculation
172  * @ctx: Context pointer from crypto_hash_init()
173  * @hash: Buffer for hash value or %NULL if caller is just freeing the hash
174  * context
175  * @len: Pointer to length of the buffer or %NULL if caller is just freeing the
176  * hash context; on return, this is set to the actual length of the hash value
177  * Returns: 0 on success, -1 if buffer is too small (len set to needed length),
178  * or -2 on other failures (including failed crypto_hash_update() operations)
179  *
180  * This function calculates the hash value and frees the context buffer that
181  * was used for hash calculation.
182  *
183  * This function is only used with internal TLSv1 implementation
184  * (CONFIG_TLS=internal). If that is not used, the crypto wrapper does not need
185  * to implement this.
186  */
187 int crypto_hash_finish(struct crypto_hash *ctx, u8 *hash, size_t *len);
188 
189 
190 enum crypto_cipher_alg {
191 	CRYPTO_CIPHER_NULL = 0, CRYPTO_CIPHER_ALG_AES, CRYPTO_CIPHER_ALG_3DES,
192 	CRYPTO_CIPHER_ALG_DES, CRYPTO_CIPHER_ALG_RC2, CRYPTO_CIPHER_ALG_RC4
193 };
194 
195 struct crypto_cipher;
196 
197 /**
198  * crypto_cipher_init - Initialize block/stream cipher function
199  * @alg: Cipher algorithm
200  * @iv: Initialization vector for block ciphers or %NULL for stream ciphers
201  * @key: Cipher key
202  * @key_len: Length of key in bytes
203  * Returns: Pointer to cipher context to use with other cipher functions or
204  * %NULL on failure
205  *
206  * This function is only used with internal TLSv1 implementation
207  * (CONFIG_TLS=internal). If that is not used, the crypto wrapper does not need
208  * to implement this.
209  */
210 struct crypto_cipher * crypto_cipher_init(enum crypto_cipher_alg alg,
211 					  const u8 *iv, const u8 *key,
212 					  size_t key_len);
213 
214 /**
215  * crypto_cipher_encrypt - Cipher encrypt
216  * @ctx: Context pointer from crypto_cipher_init()
217  * @plain: Plaintext to cipher
218  * @crypt: Resulting ciphertext
219  * @len: Length of the plaintext
220  * Returns: 0 on success, -1 on failure
221  *
222  * This function is only used with internal TLSv1 implementation
223  * (CONFIG_TLS=internal). If that is not used, the crypto wrapper does not need
224  * to implement this.
225  */
226 int __must_check crypto_cipher_encrypt(struct crypto_cipher *ctx,
227 				       const u8 *plain, u8 *crypt, size_t len);
228 
229 /**
230  * crypto_cipher_decrypt - Cipher decrypt
231  * @ctx: Context pointer from crypto_cipher_init()
232  * @crypt: Ciphertext to decrypt
233  * @plain: Resulting plaintext
234  * @len: Length of the cipher text
235  * Returns: 0 on success, -1 on failure
236  *
237  * This function is only used with internal TLSv1 implementation
238  * (CONFIG_TLS=internal). If that is not used, the crypto wrapper does not need
239  * to implement this.
240  */
241 int __must_check crypto_cipher_decrypt(struct crypto_cipher *ctx,
242 				       const u8 *crypt, u8 *plain, size_t len);
243 
244 /**
245  * crypto_cipher_decrypt - Free cipher context
246  * @ctx: Context pointer from crypto_cipher_init()
247  *
248  * This function is only used with internal TLSv1 implementation
249  * (CONFIG_TLS=internal). If that is not used, the crypto wrapper does not need
250  * to implement this.
251  */
252 void crypto_cipher_deinit(struct crypto_cipher *ctx);
253 
254 
255 struct crypto_public_key;
256 struct crypto_private_key;
257 
258 /**
259  * crypto_public_key_import - Import an RSA public key
260  * @key: Key buffer (DER encoded RSA public key)
261  * @len: Key buffer length in bytes
262  * Returns: Pointer to the public key or %NULL on failure
263  *
264  * This function can just return %NULL if the crypto library supports X.509
265  * parsing. In that case, crypto_public_key_from_cert() is used to import the
266  * public key from a certificate.
267  *
268  * This function is only used with internal TLSv1 implementation
269  * (CONFIG_TLS=internal). If that is not used, the crypto wrapper does not need
270  * to implement this.
271  */
272 struct crypto_public_key * crypto_public_key_import(const u8 *key, size_t len);
273 
274 struct crypto_public_key *
275 crypto_public_key_import_parts(const u8 *n, size_t n_len,
276 			       const u8 *e, size_t e_len);
277 
278 /**
279  * crypto_private_key_import - Import an RSA private key
280  * @key: Key buffer (DER encoded RSA private key)
281  * @len: Key buffer length in bytes
282  * @passwd: Key encryption password or %NULL if key is not encrypted
283  * Returns: Pointer to the private key or %NULL on failure
284  *
285  * This function is only used with internal TLSv1 implementation
286  * (CONFIG_TLS=internal). If that is not used, the crypto wrapper does not need
287  * to implement this.
288  */
289 struct crypto_private_key * crypto_private_key_import(const u8 *key,
290 						      size_t len,
291 						      const char *passwd);
292 
293 /**
294  * crypto_public_key_from_cert - Import an RSA public key from a certificate
295  * @buf: DER encoded X.509 certificate
296  * @len: Certificate buffer length in bytes
297  * Returns: Pointer to public key or %NULL on failure
298  *
299  * This function can just return %NULL if the crypto library does not support
300  * X.509 parsing. In that case, internal code will be used to parse the
301  * certificate and public key is imported using crypto_public_key_import().
302  *
303  * This function is only used with internal TLSv1 implementation
304  * (CONFIG_TLS=internal). If that is not used, the crypto wrapper does not need
305  * to implement this.
306  */
307 struct crypto_public_key * crypto_public_key_from_cert(const u8 *buf,
308 						       size_t len);
309 
310 /**
311  * crypto_public_key_encrypt_pkcs1_v15 - Public key encryption (PKCS #1 v1.5)
312  * @key: Public key
313  * @in: Plaintext buffer
314  * @inlen: Length of plaintext buffer in bytes
315  * @out: Output buffer for encrypted data
316  * @outlen: Length of output buffer in bytes; set to used length on success
317  * Returns: 0 on success, -1 on failure
318  *
319  * This function is only used with internal TLSv1 implementation
320  * (CONFIG_TLS=internal). If that is not used, the crypto wrapper does not need
321  * to implement this.
322  */
323 int __must_check crypto_public_key_encrypt_pkcs1_v15(
324 	struct crypto_public_key *key, const u8 *in, size_t inlen,
325 	u8 *out, size_t *outlen);
326 
327 /**
328  * crypto_private_key_decrypt_pkcs1_v15 - Private key decryption (PKCS #1 v1.5)
329  * @key: Private key
330  * @in: Encrypted buffer
331  * @inlen: Length of encrypted buffer in bytes
332  * @out: Output buffer for encrypted data
333  * @outlen: Length of output buffer in bytes; set to used length on success
334  * Returns: 0 on success, -1 on failure
335  *
336  * This function is only used with internal TLSv1 implementation
337  * (CONFIG_TLS=internal). If that is not used, the crypto wrapper does not need
338  * to implement this.
339  */
340 int __must_check crypto_private_key_decrypt_pkcs1_v15(
341 	struct crypto_private_key *key, const u8 *in, size_t inlen,
342 	u8 *out, size_t *outlen);
343 
344 /**
345  * crypto_private_key_sign_pkcs1 - Sign with private key (PKCS #1)
346  * @key: Private key from crypto_private_key_import()
347  * @in: Plaintext buffer
348  * @inlen: Length of plaintext buffer in bytes
349  * @out: Output buffer for encrypted (signed) data
350  * @outlen: Length of output buffer in bytes; set to used length on success
351  * Returns: 0 on success, -1 on failure
352  *
353  * This function is only used with internal TLSv1 implementation
354  * (CONFIG_TLS=internal). If that is not used, the crypto wrapper does not need
355  * to implement this.
356  */
357 int __must_check crypto_private_key_sign_pkcs1(struct crypto_private_key *key,
358 					       const u8 *in, size_t inlen,
359 					       u8 *out, size_t *outlen);
360 
361 /**
362  * crypto_public_key_free - Free public key
363  * @key: Public key
364  *
365  * This function is only used with internal TLSv1 implementation
366  * (CONFIG_TLS=internal). If that is not used, the crypto wrapper does not need
367  * to implement this.
368  */
369 void crypto_public_key_free(struct crypto_public_key *key);
370 
371 /**
372  * crypto_private_key_free - Free private key
373  * @key: Private key from crypto_private_key_import()
374  *
375  * This function is only used with internal TLSv1 implementation
376  * (CONFIG_TLS=internal). If that is not used, the crypto wrapper does not need
377  * to implement this.
378  */
379 void crypto_private_key_free(struct crypto_private_key *key);
380 
381 /**
382  * crypto_public_key_decrypt_pkcs1 - Decrypt PKCS #1 signature
383  * @key: Public key
384  * @crypt: Encrypted signature data (using the private key)
385  * @crypt_len: Encrypted signature data length
386  * @plain: Buffer for plaintext (at least crypt_len bytes)
387  * @plain_len: Plaintext length (max buffer size on input, real len on output);
388  * Returns: 0 on success, -1 on failure
389  */
390 int __must_check crypto_public_key_decrypt_pkcs1(
391 	struct crypto_public_key *key, const u8 *crypt, size_t crypt_len,
392 	u8 *plain, size_t *plain_len);
393 
394 /**
395  * crypto_global_init - Initialize crypto wrapper
396  *
397  * This function is only used with internal TLSv1 implementation
398  * (CONFIG_TLS=internal). If that is not used, the crypto wrapper does not need
399  * to implement this.
400  */
401 int __must_check crypto_global_init(void);
402 
403 /**
404  * crypto_global_deinit - Deinitialize crypto wrapper
405  *
406  * This function is only used with internal TLSv1 implementation
407  * (CONFIG_TLS=internal). If that is not used, the crypto wrapper does not need
408  * to implement this.
409  */
410 void crypto_global_deinit(void);
411 
412 /**
413  * crypto_mod_exp - Modular exponentiation of large integers
414  * @base: Base integer (big endian byte array)
415  * @base_len: Length of base integer in bytes
416  * @power: Power integer (big endian byte array)
417  * @power_len: Length of power integer in bytes
418  * @modulus: Modulus integer (big endian byte array)
419  * @modulus_len: Length of modulus integer in bytes
420  * @result: Buffer for the result
421  * @result_len: Result length (max buffer size on input, real len on output)
422  * Returns: 0 on success, -1 on failure
423  *
424  * This function calculates result = base ^ power mod modulus. modules_len is
425  * used as the maximum size of modulus buffer. It is set to the used size on
426  * success.
427  *
428  * This function is only used with internal TLSv1 implementation
429  * (CONFIG_TLS=internal). If that is not used, the crypto wrapper does not need
430  * to implement this.
431  */
432 int __must_check crypto_mod_exp(const u8 *base, size_t base_len,
433 				const u8 *power, size_t power_len,
434 				const u8 *modulus, size_t modulus_len,
435 				u8 *result, size_t *result_len);
436 
437 /**
438  * rc4_skip - XOR RC4 stream to given data with skip-stream-start
439  * @key: RC4 key
440  * @keylen: RC4 key length
441  * @skip: number of bytes to skip from the beginning of the RC4 stream
442  * @data: data to be XOR'ed with RC4 stream
443  * @data_len: buf length
444  * Returns: 0 on success, -1 on failure
445  *
446  * Generate RC4 pseudo random stream for the given key, skip beginning of the
447  * stream, and XOR the end result with the data buffer to perform RC4
448  * encryption/decryption.
449  */
450 int rc4_skip(const u8 *key, size_t keylen, size_t skip,
451 	     u8 *data, size_t data_len);
452 
453 /**
454  * crypto_get_random - Generate cryptographically strong pseudy-random bytes
455  * @buf: Buffer for data
456  * @len: Number of bytes to generate
457  * Returns: 0 on success, -1 on failure
458  *
459  * If the PRNG does not have enough entropy to ensure unpredictable byte
460  * sequence, this functions must return -1.
461  */
462 int crypto_get_random(void *buf, size_t len);
463 
464 
465 /**
466  * struct crypto_bignum - bignum
467  *
468  * Internal data structure for bignum implementation. The contents is specific
469  * to the used crypto library.
470  */
471 struct crypto_bignum;
472 
473 /**
474  * crypto_bignum_init - Allocate memory for bignum
475  * Returns: Pointer to allocated bignum or %NULL on failure
476  */
477 struct crypto_bignum * crypto_bignum_init(void);
478 
479 /**
480  * crypto_bignum_init_set - Allocate memory for bignum and set the value
481  * @buf: Buffer with unsigned binary value
482  * @len: Length of buf in octets
483  * Returns: Pointer to allocated bignum or %NULL on failure
484  */
485 struct crypto_bignum * crypto_bignum_init_set(const u8 *buf, size_t len);
486 
487 /**
488  * crypto_bignum_deinit - Free bignum
489  * @n: Bignum from crypto_bignum_init() or crypto_bignum_init_set()
490  * @clear: Whether to clear the value from memory
491  */
492 void crypto_bignum_deinit(struct crypto_bignum *n, int clear);
493 
494 /**
495  * crypto_bignum_to_bin - Set binary buffer to unsigned bignum
496  * @a: Bignum
497  * @buf: Buffer for the binary number
498  * @len: Length of @buf in octets
499  * @padlen: Length in octets to pad the result to or 0 to indicate no padding
500  * Returns: Number of octets written on success, -1 on failure
501  */
502 int crypto_bignum_to_bin(const struct crypto_bignum *a,
503 			 u8 *buf, size_t buflen, size_t padlen);
504 
505 /**
506  * crypto_bignum_add - c = a + b
507  * @a: Bignum
508  * @b: Bignum
509  * @c: Bignum; used to store the result of a + b
510  * Returns: 0 on success, -1 on failure
511  */
512 int crypto_bignum_add(const struct crypto_bignum *a,
513 		      const struct crypto_bignum *b,
514 		      struct crypto_bignum *c);
515 
516 /**
517  * crypto_bignum_mod - c = a % b
518  * @a: Bignum
519  * @b: Bignum
520  * @c: Bignum; used to store the result of a % b
521  * Returns: 0 on success, -1 on failure
522  */
523 int crypto_bignum_mod(const struct crypto_bignum *a,
524 		      const struct crypto_bignum *b,
525 		      struct crypto_bignum *c);
526 
527 /**
528  * crypto_bignum_exptmod - Modular exponentiation: d = a^b (mod c)
529  * @a: Bignum; base
530  * @b: Bignum; exponent
531  * @c: Bignum; modulus
532  * @d: Bignum; used to store the result of a^b (mod c)
533  * Returns: 0 on success, -1 on failure
534  */
535 int crypto_bignum_exptmod(const struct crypto_bignum *a,
536 			  const struct crypto_bignum *b,
537 			  const struct crypto_bignum *c,
538 			  struct crypto_bignum *d);
539 
540 /**
541  * crypto_bignum_inverse - Inverse a bignum so that a * c = 1 (mod b)
542  * @a: Bignum
543  * @b: Bignum
544  * @c: Bignum; used to store the result
545  * Returns: 0 on success, -1 on failure
546  */
547 int crypto_bignum_inverse(const struct crypto_bignum *a,
548 			  const struct crypto_bignum *b,
549 			  struct crypto_bignum *c);
550 
551 /**
552  * crypto_bignum_sub - c = a - b
553  * @a: Bignum
554  * @b: Bignum
555  * @c: Bignum; used to store the result of a - b
556  * Returns: 0 on success, -1 on failure
557  */
558 int crypto_bignum_sub(const struct crypto_bignum *a,
559 		      const struct crypto_bignum *b,
560 		      struct crypto_bignum *c);
561 
562 /**
563  * crypto_bignum_div - c = a / b
564  * @a: Bignum
565  * @b: Bignum
566  * @c: Bignum; used to store the result of a / b
567  * Returns: 0 on success, -1 on failure
568  */
569 int crypto_bignum_div(const struct crypto_bignum *a,
570 		      const struct crypto_bignum *b,
571 		      struct crypto_bignum *c);
572 
573 /**
574  * crypto_bignum_mulmod - d = a * b (mod c)
575  * @a: Bignum
576  * @b: Bignum
577  * @c: Bignum
578  * @d: Bignum; used to store the result of (a * b) % c
579  * Returns: 0 on success, -1 on failure
580  */
581 int crypto_bignum_mulmod(const struct crypto_bignum *a,
582 			 const struct crypto_bignum *b,
583 			 const struct crypto_bignum *c,
584 			 struct crypto_bignum *d);
585 
586 /**
587  * crypto_bignum_cmp - Compare two bignums
588  * @a: Bignum
589  * @b: Bignum
590  * Returns: -1 if a < b, 0 if a == b, or 1 if a > b
591  */
592 int crypto_bignum_cmp(const struct crypto_bignum *a,
593 		      const struct crypto_bignum *b);
594 
595 /**
596  * crypto_bignum_bits - Get size of a bignum in bits
597  * @a: Bignum
598  * Returns: Number of bits in the bignum
599  */
600 int crypto_bignum_bits(const struct crypto_bignum *a);
601 
602 /**
603  * crypto_bignum_is_zero - Is the given bignum zero
604  * @a: Bignum
605  * Returns: 1 if @a is zero or 0 if not
606  */
607 int crypto_bignum_is_zero(const struct crypto_bignum *a);
608 
609 /**
610  * crypto_bignum_is_one - Is the given bignum one
611  * @a: Bignum
612  * Returns: 1 if @a is one or 0 if not
613  */
614 int crypto_bignum_is_one(const struct crypto_bignum *a);
615 
616 /**
617  * crypto_bignum_legendre - Compute the Legendre symbol (a/p)
618  * @a: Bignum
619  * @p: Bignum
620  * Returns: Legendre symbol -1,0,1 on success; -2 on calculation failure
621  */
622 int crypto_bignum_legendre(const struct crypto_bignum *a,
623 			   const struct crypto_bignum *p);
624 
625 /**
626  * struct crypto_ec - Elliptic curve context
627  *
628  * Internal data structure for EC implementation. The contents is specific
629  * to the used crypto library.
630  */
631 struct crypto_ec;
632 
633 /**
634  * crypto_ec_init - Initialize elliptic curve context
635  * @group: Identifying number for the ECC group (IANA "Group Description"
636  *	attribute registrty for RFC 2409)
637  * Returns: Pointer to EC context or %NULL on failure
638  */
639 struct crypto_ec * crypto_ec_init(int group);
640 
641 /**
642  * crypto_ec_deinit - Deinitialize elliptic curve context
643  * @e: EC context from crypto_ec_init()
644  */
645 void crypto_ec_deinit(struct crypto_ec *e);
646 
647 /**
648  * crypto_ec_prime_len - Get length of the prime in octets
649  * @e: EC context from crypto_ec_init()
650  * Returns: Length of the prime defining the group
651  */
652 size_t crypto_ec_prime_len(struct crypto_ec *e);
653 
654 /**
655  * crypto_ec_prime_len_bits - Get length of the prime in bits
656  * @e: EC context from crypto_ec_init()
657  * Returns: Length of the prime defining the group in bits
658  */
659 size_t crypto_ec_prime_len_bits(struct crypto_ec *e);
660 
661 /**
662  * crypto_ec_get_prime - Get prime defining an EC group
663  * @e: EC context from crypto_ec_init()
664  * Returns: Prime (bignum) defining the group
665  */
666 const struct crypto_bignum * crypto_ec_get_prime(struct crypto_ec *e);
667 
668 /**
669  * crypto_ec_get_order - Get order of an EC group
670  * @e: EC context from crypto_ec_init()
671  * Returns: Order (bignum) of the group
672  */
673 const struct crypto_bignum * crypto_ec_get_order(struct crypto_ec *e);
674 
675 /**
676  * struct crypto_ec_point - Elliptic curve point
677  *
678  * Internal data structure for EC implementation to represent a point. The
679  * contents is specific to the used crypto library.
680  */
681 struct crypto_ec_point;
682 
683 /**
684  * crypto_ec_point_init - Initialize data for an EC point
685  * @e: EC context from crypto_ec_init()
686  * Returns: Pointer to EC point data or %NULL on failure
687  */
688 struct crypto_ec_point * crypto_ec_point_init(struct crypto_ec *e);
689 
690 /**
691  * crypto_ec_point_deinit - Deinitialize EC point data
692  * @p: EC point data from crypto_ec_point_init()
693  * @clear: Whether to clear the EC point value from memory
694  */
695 void crypto_ec_point_deinit(struct crypto_ec_point *p, int clear);
696 
697 /**
698  * crypto_ec_point_to_bin - Write EC point value as binary data
699  * @e: EC context from crypto_ec_init()
700  * @p: EC point data from crypto_ec_point_init()
701  * @x: Buffer for writing the binary data for x coordinate or %NULL if not used
702  * @y: Buffer for writing the binary data for y coordinate or %NULL if not used
703  * Returns: 0 on success, -1 on failure
704  *
705  * This function can be used to write an EC point as binary data in a format
706  * that has the x and y coordinates in big endian byte order fields padded to
707  * the length of the prime defining the group.
708  */
709 int crypto_ec_point_to_bin(struct crypto_ec *e,
710 			   const struct crypto_ec_point *point, u8 *x, u8 *y);
711 
712 /**
713  * crypto_ec_point_from_bin - Create EC point from binary data
714  * @e: EC context from crypto_ec_init()
715  * @val: Binary data to read the EC point from
716  * Returns: Pointer to EC point data or %NULL on failure
717  *
718  * This function readers x and y coordinates of the EC point from the provided
719  * buffer assuming the values are in big endian byte order with fields padded to
720  * the length of the prime defining the group.
721  */
722 struct crypto_ec_point * crypto_ec_point_from_bin(struct crypto_ec *e,
723 						  const u8 *val);
724 
725 /**
726  * crypto_bignum_add - c = a + b
727  * @e: EC context from crypto_ec_init()
728  * @a: Bignum
729  * @b: Bignum
730  * @c: Bignum; used to store the result of a + b
731  * Returns: 0 on success, -1 on failure
732  */
733 int crypto_ec_point_add(struct crypto_ec *e, const struct crypto_ec_point *a,
734 			const struct crypto_ec_point *b,
735 			struct crypto_ec_point *c);
736 
737 /**
738  * crypto_bignum_mul - res = b * p
739  * @e: EC context from crypto_ec_init()
740  * @p: EC point
741  * @b: Bignum
742  * @res: EC point; used to store the result of b * p
743  * Returns: 0 on success, -1 on failure
744  */
745 int crypto_ec_point_mul(struct crypto_ec *e, const struct crypto_ec_point *p,
746 			const struct crypto_bignum *b,
747 			struct crypto_ec_point *res);
748 
749 /**
750  * crypto_ec_point_invert - Compute inverse of an EC point
751  * @e: EC context from crypto_ec_init()
752  * @p: EC point to invert (and result of the operation)
753  * Returns: 0 on success, -1 on failure
754  */
755 int crypto_ec_point_invert(struct crypto_ec *e, struct crypto_ec_point *p);
756 
757 /**
758  * crypto_ec_point_solve_y_coord - Solve y coordinate for an x coordinate
759  * @e: EC context from crypto_ec_init()
760  * @p: EC point to use for the returning the result
761  * @x: x coordinate
762  * @y_bit: y-bit (0 or 1) for selecting the y value to use
763  * Returns: 0 on success, -1 on failure
764  */
765 int crypto_ec_point_solve_y_coord(struct crypto_ec *e,
766 				  struct crypto_ec_point *p,
767 				  const struct crypto_bignum *x, int y_bit);
768 
769 /**
770  * crypto_ec_point_compute_y_sqr - Compute y^2 = x^3 + ax + b
771  * @e: EC context from crypto_ec_init()
772  * @x: x coordinate
773  * Returns: y^2 on success, %NULL failure
774  */
775 struct crypto_bignum *
776 crypto_ec_point_compute_y_sqr(struct crypto_ec *e,
777 			      const struct crypto_bignum *x);
778 
779 /**
780  * crypto_ec_point_is_at_infinity - Check whether EC point is neutral element
781  * @e: EC context from crypto_ec_init()
782  * @p: EC point
783  * Returns: 1 if the specified EC point is the neutral element of the group or
784  *	0 if not
785  */
786 int crypto_ec_point_is_at_infinity(struct crypto_ec *e,
787 				   const struct crypto_ec_point *p);
788 
789 /**
790  * crypto_ec_point_is_on_curve - Check whether EC point is on curve
791  * @e: EC context from crypto_ec_init()
792  * @p: EC point
793  * Returns: 1 if the specified EC point is on the curve or 0 if not
794  */
795 int crypto_ec_point_is_on_curve(struct crypto_ec *e,
796 				const struct crypto_ec_point *p);
797 
798 /**
799  * crypto_ec_point_cmp - Compare two EC points
800  * @e: EC context from crypto_ec_init()
801  * @a: EC point
802  * @b: EC point
803  * Returns: 0 on equal, non-zero otherwise
804  */
805 int crypto_ec_point_cmp(const struct crypto_ec *e,
806 			const struct crypto_ec_point *a,
807 			const struct crypto_ec_point *b);
808 
809 #endif /* CRYPTO_H */
810