282 lines
8.6 KiB
C
282 lines
8.6 KiB
C
|
/*
|
||
|
|
* 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);
|
||
|
|
|
||
|
|
/**
|
||
|
|
* vli_num_bits() - Counts the number of bits required for vli.
|
||
|
|
*
|
||
|
|
* @vli: vli to check.
|
||
|
|
* @ndigits: Length of the @vli
|
||
|
|
*
|
||
|
|
* Return: The number of bits required to represent @vli.
|
||
|
|
*/
|
||
|
|
unsigned int vli_num_bits(const u64 *vli, unsigned int ndigits);
|
||
|
|
|
||
|
|
/**
|
||
|
|
* ecc_aloc_point() - Allocate ECC point.
|
||
|
|
*
|
||
|
|
* @ndigits: Length of vlis in u64 qwords.
|
||
|
|
*
|
||
|
|
* Return: Pointer to the allocated point or NULL if allocation failed.
|
||
|
|
*/
|
||
|
|
struct ecc_point *ecc_alloc_point(unsigned int ndigits);
|
||
|
|
|
||
|
|
/**
|
||
|
|
* ecc_free_point() - Free ECC point.
|
||
|
|
*
|
||
|
|
* @p: The point to free.
|
||
|
|
*/
|
||
|
|
void ecc_free_point(struct ecc_point *p);
|
||
|
|
|
||
|
|
/**
|
||
|
|
* ecc_point_is_zero() - Check if point is zero.
|
||
|
|
*
|
||
|
|
* @p: Point to check for zero.
|
||
|
|
*
|
||
|
|
* Return: true if point is the point at infinity, false otherwise.
|
||
|
|
*/
|
||
|
|
bool ecc_point_is_zero(const struct ecc_point *point);
|
||
|
|
|
||
|
|
/**
|
||
|
|
* 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
|