[mirror_ubuntu-jammy-kernel.git] / crypto / ecc.h

/*
 * Copyright (c) 2013, Kenneth MacKay
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *  * Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 *  * Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
#ifndef _CRYPTO_ECC_H
#define _CRYPTO_ECC_H

#include <crypto/ecc_curve.h>
#include <asm/unaligned.h>

/* One digit is u64 qword. */
#define ECC_CURVE_NIST_P192_DIGITS  3
#define ECC_CURVE_NIST_P256_DIGITS  4
#define ECC_CURVE_NIST_P384_DIGITS  6
#define ECC_MAX_DIGITS              (512 / 64) /* due to ecrdsa */

#define ECC_DIGITS_TO_BYTES_SHIFT 3

#define ECC_MAX_BYTES (ECC_MAX_DIGITS << ECC_DIGITS_TO_BYTES_SHIFT)

#define ECC_POINT_INIT(x, y, ndigits)	(struct ecc_point) { x, y, ndigits }

/**
 * ecc_swap_digits() - Copy ndigits from big endian array to native array
 * @in:       Input array
 * @out:      Output array
 * @ndigits:  Number of digits to copy
 */
static inline void ecc_swap_digits(const void *in, u64 *out, unsigned int ndigits)
{
	const __be64 *src = (__force __be64 *)in;
	int i;

	for (i = 0; i < ndigits; i++)
		out[i] = get_unaligned_be64(&src[ndigits - 1 - i]);
}

/**
 * ecc_is_key_valid() - Validate a given ECDH private key
 *
 * @curve_id:		id representing the curve to use
 * @ndigits:		curve's number of digits
 * @private_key:	private key to be used for the given curve
 * @private_key_len:	private key length
 *
 * Returns 0 if the key is acceptable, a negative value otherwise
 */
int ecc_is_key_valid(unsigned int curve_id, unsigned int ndigits,
		     const u64 *private_key, unsigned int private_key_len);

/**
 * ecc_gen_privkey() -  Generates an ECC private key.
 * The private key is a random integer in the range 0 < random < n, where n is a
 * prime that is the order of the cyclic subgroup generated by the distinguished
 * point G.
 * @curve_id:		id representing the curve to use
 * @ndigits:		curve number of digits
 * @private_key:	buffer for storing the generated private key
 *
 * Returns 0 if the private key was generated successfully, a negative value
 * if an error occurred.
 */
int ecc_gen_privkey(unsigned int curve_id, unsigned int ndigits, u64 *privkey);

/**
 * ecc_make_pub_key() - Compute an ECC public key
 *
 * @curve_id:		id representing the curve to use
 * @ndigits:		curve's number of digits
 * @private_key:	pregenerated private key for the given curve
 * @public_key:		buffer for storing the generated public key
 *
 * Returns 0 if the public key was generated successfully, a negative value
 * if an error occurred.
 */
int ecc_make_pub_key(const unsigned int curve_id, unsigned int ndigits,
		     const u64 *private_key, u64 *public_key);

/**
 * crypto_ecdh_shared_secret() - Compute a shared secret
 *
 * @curve_id:		id representing the curve to use
 * @ndigits:		curve's number of digits
 * @private_key:	private key of part A
 * @public_key:		public key of counterpart B
 * @secret:		buffer for storing the calculated shared secret
 *
 * Note: It is recommended that you hash the result of crypto_ecdh_shared_secret
 * before using it for symmetric encryption or HMAC.
 *
 * Returns 0 if the shared secret was generated successfully, a negative value
 * if an error occurred.
 */
int crypto_ecdh_shared_secret(unsigned int curve_id, unsigned int ndigits,
			      const u64 *private_key, const u64 *public_key,
			      u64 *secret);

/**
 * ecc_is_pubkey_valid_partial() - Partial public key validation
 *
 * @curve:		elliptic curve domain parameters
 * @pk:			public key as a point
 *
 * Valdiate public key according to SP800-56A section 5.6.2.3.4 ECC Partial
 * Public-Key Validation Routine.
 *
 * Note: There is no check that the public key is in the correct elliptic curve
 * subgroup.
 *
 * Return: 0 if validation is successful, -EINVAL if validation is failed.
 */
int ecc_is_pubkey_valid_partial(const struct ecc_curve *curve,
				struct ecc_point *pk);

/**
 * ecc_is_pubkey_valid_full() - Full public key validation
 *
 * @curve:		elliptic curve domain parameters
 * @pk:			public key as a point
 *
 * Valdiate public key according to SP800-56A section 5.6.2.3.3 ECC Full
 * Public-Key Validation Routine.
 *
 * Return: 0 if validation is successful, -EINVAL if validation is failed.
 */
int ecc_is_pubkey_valid_full(const struct ecc_curve *curve,
			     struct ecc_point *pk);

/**
 * vli_is_zero() - Determine is vli is zero
 *
 * @vli:		vli to check.
 * @ndigits:		length of the @vli
 */
bool vli_is_zero(const u64 *vli, unsigned int ndigits);

/**
 * vli_cmp() - compare left and right vlis
 *
 * @left:		vli
 * @right:		vli
 * @ndigits:		length of both vlis
 *
 * Returns sign of @left - @right, i.e. -1 if @left < @right,
 * 0 if @left == @right, 1 if @left > @right.
 */
int vli_cmp(const u64 *left, const u64 *right, unsigned int ndigits);

/**
 * vli_sub() - Subtracts right from left
 *
 * @result:		where to write result
 * @left:		vli
 * @right		vli
 * @ndigits:		length of all vlis
 *
 * Note: can modify in-place.
 *
 * Return: carry bit.
 */
u64 vli_sub(u64 *result, const u64 *left, const u64 *right,
	    unsigned int ndigits);

/**
 * vli_from_be64() - Load vli from big-endian u64 array
 *
 * @dest:		destination vli
 * @src:		source array of u64 BE values
 * @ndigits:		length of both vli and array
 */
void vli_from_be64(u64 *dest, const void *src, unsigned int ndigits);

/**
 * vli_from_le64() - Load vli from little-endian u64 array
 *
 * @dest:		destination vli
 * @src:		source array of u64 LE values
 * @ndigits:		length of both vli and array
 */
void vli_from_le64(u64 *dest, const void *src, unsigned int ndigits);

/**
 * vli_mod_inv() - Modular inversion
 *
 * @result:		where to write vli number
 * @input:		vli value to operate on
 * @mod:		modulus
 * @ndigits:		length of all vlis
 */
void vli_mod_inv(u64 *result, const u64 *input, const u64 *mod,
		 unsigned int ndigits);

/**
 * vli_mod_mult_slow() - Modular multiplication
 *
 * @result:		where to write result value
 * @left:		vli number to multiply with @right
 * @right:		vli number to multiply with @left
 * @mod:		modulus
 * @ndigits:		length of all vlis
 *
 * Note: Assumes that mod is big enough curve order.
 */
void vli_mod_mult_slow(u64 *result, const u64 *left, const u64 *right,
		       const u64 *mod, unsigned int ndigits);

/**
 * ecc_point_mult_shamir() - Add two points multiplied by scalars
 *
 * @result:		resulting point
 * @x:			scalar to multiply with @p
 * @p:			point to multiply with @x
 * @y:			scalar to multiply with @q
 * @q:			point to multiply with @y
 * @curve:		curve
 *
 * Returns result = x * p + x * q over the curve.
 * This works faster than two multiplications and addition.
 */
void ecc_point_mult_shamir(const struct ecc_point *result,
			   const u64 *x, const struct ecc_point *p,
			   const u64 *y, const struct ecc_point *q,
			   const struct ecc_curve *curve);
#endif
Commit	Line	Data
3c4b2390 SB	1	/*
	2	* Copyright (c) 2013, Kenneth MacKay
	3	* All rights reserved.
	4	*
	5	* Redistribution and use in source and binary forms, with or without
	6	* modification, are permitted provided that the following conditions are
	7	* met:
	8	* * Redistributions of source code must retain the above copyright
	9	* notice, this list of conditions and the following disclaimer.
	10	* * Redistributions in binary form must reproduce the above copyright
	11	* notice, this list of conditions and the following disclaimer in the
	12	* documentation and/or other materials provided with the distribution.
	13	*
	14	* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
	15	* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
	16	* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
	17	* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
	18	* HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
	19	* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
	20	* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	21	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	22	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	23	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
	24	* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	25	*/
	26	#ifndef _CRYPTO_ECC_H
	27	#define _CRYPTO_ECC_H
	28
14bb7676	29	#include <crypto/ecc_curve.h>
0469dede	30	#include <asm/unaligned.h>
14bb7676	31
0d7a7864	32	/* One digit is u64 qword. */
d5c3b178 KC	33	#define ECC_CURVE_NIST_P192_DIGITS 3
d5c3b178 KC	34	#define ECC_CURVE_NIST_P256_DIGITS 4
149ca161 SA	35	#define ECC_CURVE_NIST_P384_DIGITS 6
149ca161 SA	36	#define ECC_MAX_DIGITS (512 / 64) /* due to ecrdsa */
3c4b2390 SB	37
	38	#define ECC_DIGITS_TO_BYTES_SHIFT 3
	39
4e660291 SB	40	#define ECC_MAX_BYTES (ECC_MAX_DIGITS << ECC_DIGITS_TO_BYTES_SHIFT)
4e660291 SB	41
0d7a7864 VC	42	#define ECC_POINT_INIT(x, y, ndigits) (struct ecc_point) { x, y, ndigits }
0d7a7864 VC	43
4e660291 SB	44	/**
	45	* ecc_swap_digits() - Copy ndigits from big endian array to native array
	46	* @in: Input array
	47	* @out: Output array
	48	* @ndigits: Number of digits to copy
	49	*/
0469dede	50	static inline void ecc_swap_digits(const void in, u64 out, unsigned int ndigits)
4e660291 SB	51	{
	52	const __be64 src = (__force __be64 )in;
	53	int i;
	54
	55	for (i = 0; i < ndigits; i++)
0469dede	56	out[i] = get_unaligned_be64(&src[ndigits - 1 - i]);
4e660291 SB	57	}
4e660291 SB	58
3c4b2390 SB	59	/**
	60	* ecc_is_key_valid() - Validate a given ECDH private key
	61	*
	62	* @curve_id: id representing the curve to use
c0ca1215	63	* @ndigits: curve's number of digits
3c4b2390	64	* @private_key: private key to be used for the given curve
c0ca1215	65	* @private_key_len: private key length
3c4b2390 SB	66	*
	67	* Returns 0 if the key is acceptable, a negative value otherwise
	68	*/
	69	int ecc_is_key_valid(unsigned int curve_id, unsigned int ndigits,
ad269597	70	const u64 *private_key, unsigned int private_key_len);
3c4b2390	71
6755fd26 TDA	72	/**
	73	* ecc_gen_privkey() - Generates an ECC private key.
	74	* The private key is a random integer in the range 0 < random < n, where n is a
	75	* prime that is the order of the cyclic subgroup generated by the distinguished
	76	* point G.
	77	* @curve_id: id representing the curve to use
	78	* @ndigits: curve number of digits
	79	* @private_key: buffer for storing the generated private key
	80	*
	81	* Returns 0 if the private key was generated successfully, a negative value
	82	* if an error occurred.
	83	*/
	84	int ecc_gen_privkey(unsigned int curve_id, unsigned int ndigits, u64 *privkey);
	85
3c4b2390	86	/**
7380c56d	87	* ecc_make_pub_key() - Compute an ECC public key
3c4b2390 SB	88	*
3c4b2390 SB	89	* @curve_id: id representing the curve to use
c0ca1215	90	* @ndigits: curve's number of digits
3c4b2390	91	* @private_key: pregenerated private key for the given curve
c0ca1215	92	* @public_key: buffer for storing the generated public key
3c4b2390 SB	93	*
	94	* Returns 0 if the public key was generated successfully, a negative value
	95	* if an error occurred.
	96	*/
7380c56d TDA	97	int ecc_make_pub_key(const unsigned int curve_id, unsigned int ndigits,
7380c56d TDA	98	const u64 private_key, u64 public_key);
3c4b2390 SB	99
3c4b2390 SB	100	/**
8f44df15	101	* crypto_ecdh_shared_secret() - Compute a shared secret
3c4b2390 SB	102	*
3c4b2390 SB	103	* @curve_id: id representing the curve to use
c0ca1215	104	* @ndigits: curve's number of digits
3c4b2390	105	* @private_key: private key of part A
3c4b2390	106	* @public_key: public key of counterpart B
3c4b2390	107	* @secret: buffer for storing the calculated shared secret
3c4b2390	108	*
8f44df15	109	* Note: It is recommended that you hash the result of crypto_ecdh_shared_secret
3c4b2390 SB	110	* before using it for symmetric encryption or HMAC.
	111	*
	112	* Returns 0 if the shared secret was generated successfully, a negative value
	113	* if an error occurred.
	114	*/
8f44df15	115	int crypto_ecdh_shared_secret(unsigned int curve_id, unsigned int ndigits,
ad269597 TDA	116	const u64 private_key, const u64 public_key,
ad269597 TDA	117	u64 *secret);
4a2289da VC	118
	119	/**
	120	* ecc_is_pubkey_valid_partial() - Partial public key validation
	121	*
	122	* @curve: elliptic curve domain parameters
	123	* @pk: public key as a point
	124	*
	125	* Valdiate public key according to SP800-56A section 5.6.2.3.4 ECC Partial
	126	* Public-Key Validation Routine.
	127	*
	128	* Note: There is no check that the public key is in the correct elliptic curve
	129	* subgroup.
	130	*
	131	* Return: 0 if validation is successful, -EINVAL if validation is failed.
	132	*/
	133	int ecc_is_pubkey_valid_partial(const struct ecc_curve *curve,
	134	struct ecc_point *pk);
	135
6914dd53 SM	136	/**
	137	* ecc_is_pubkey_valid_full() - Full public key validation
	138	*
	139	* @curve: elliptic curve domain parameters
	140	* @pk: public key as a point
	141	*
	142	* Valdiate public key according to SP800-56A section 5.6.2.3.3 ECC Full
	143	* Public-Key Validation Routine.
	144	*
	145	* Return: 0 if validation is successful, -EINVAL if validation is failed.
	146	*/
	147	int ecc_is_pubkey_valid_full(const struct ecc_curve *curve,
	148	struct ecc_point *pk);
	149
4a2289da VC	150	/**
	151	* vli_is_zero() - Determine is vli is zero
	152	*
	153	* @vli: vli to check.
	154	* @ndigits: length of the @vli
	155	*/
	156	bool vli_is_zero(const u64 *vli, unsigned int ndigits);
	157
	158	/**
	159	* vli_cmp() - compare left and right vlis
	160	*
	161	* @left: vli
	162	* @right: vli
	163	* @ndigits: length of both vlis
	164	*
	165	* Returns sign of @left - @right, i.e. -1 if @left < @right,
	166	* 0 if @left == @right, 1 if @left > @right.
	167	*/
	168	int vli_cmp(const u64 left, const u64 right, unsigned int ndigits);
	169
	170	/**
	171	* vli_sub() - Subtracts right from left
	172	*
	173	* @result: where to write result
	174	* @left: vli
	175	* @right vli
	176	* @ndigits: length of all vlis
	177	*
	178	* Note: can modify in-place.
	179	*
	180	* Return: carry bit.
	181	*/
	182	u64 vli_sub(u64 result, const u64 left, const u64 *right,
	183	unsigned int ndigits);
	184
0d7a7864 VC	185	/**
	186	* vli_from_be64() - Load vli from big-endian u64 array
	187	*
	188	* @dest: destination vli
	189	* @src: source array of u64 BE values
	190	* @ndigits: length of both vli and array
	191	*/
	192	void vli_from_be64(u64 dest, const void src, unsigned int ndigits);
	193
	194	/**
	195	* vli_from_le64() - Load vli from little-endian u64 array
	196	*
	197	* @dest: destination vli
	198	* @src: source array of u64 LE values
	199	* @ndigits: length of both vli and array
	200	*/
	201	void vli_from_le64(u64 dest, const void src, unsigned int ndigits);
	202
4a2289da VC	203	/**
	204	* vli_mod_inv() - Modular inversion
	205	*
	206	* @result: where to write vli number
	207	* @input: vli value to operate on
	208	* @mod: modulus
	209	* @ndigits: length of all vlis
	210	*/
	211	void vli_mod_inv(u64 result, const u64 input, const u64 *mod,
	212	unsigned int ndigits);
	213
0d7a7864 VC	214	/**
	215	* vli_mod_mult_slow() - Modular multiplication
	216	*
	217	* @result: where to write result value
	218	* @left: vli number to multiply with @right
	219	* @right: vli number to multiply with @left
	220	* @mod: modulus
	221	* @ndigits: length of all vlis
	222	*
	223	* Note: Assumes that mod is big enough curve order.
	224	*/
	225	void vli_mod_mult_slow(u64 result, const u64 left, const u64 *right,
	226	const u64 *mod, unsigned int ndigits);
	227
	228	/**
	229	* ecc_point_mult_shamir() - Add two points multiplied by scalars
	230	*
	231	* @result: resulting point
	232	* @x: scalar to multiply with @p
	233	* @p: point to multiply with @x
	234	* @y: scalar to multiply with @q
	235	* @q: point to multiply with @y
	236	* @curve: curve
	237	*
	238	* Returns result = x * p + x * q over the curve.
	239	* This works faster than two multiplications and addition.
	240	*/
	241	void ecc_point_mult_shamir(const struct ecc_point *result,
	242	const u64 x, const struct ecc_point p,
	243	const u64 y, const struct ecc_point q,
	244	const struct ecc_curve *curve);
3c4b2390	245	#endif