/* * 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 /* One digit is u64 qword. */#define ECC_CURVE_NIST_P192_DIGITS 3#define ECC_CURVE_NIST_P256_DIGITS 4#define ECC_MAX_DIGITS (512 / 64) #define ECC_DIGITS_TO_BYTES_SHIFT 3 /** * struct ecc_point - elliptic curve point in affine coordinates * * @x: X coordinate in vli form. * @y: Y coordinate in vli form. * @ndigits: Length of vlis in u64 qwords. */struct ecc_point { u64 *x; u64 *y; u8 ndigits;}; #define ECC_POINT_INIT(x, y, ndigits) (struct ecc_point) { x, y, ndigits } /** * struct ecc_curve - definition of elliptic curve * * @name: Short name of the curve. * @g: Generator point of the curve. * @p: Prime number, if Barrett's reduction is used for this curve * pre-calculated value 'mu' is appended to the @p after ndigits. * Use of Barrett's reduction is heuristically determined in * vli_mmod_fast(). * @n: Order of the curve group. * @a: Curve parameter a. * @b: Curve parameter b. */struct ecc_curve { char *name; struct ecc_point g; u64 *p; u64 *n; u64 *a; u64 *b;}; /** * 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
/*
* 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
/* One digit is u64 qword. */
#define ECC_CURVE_NIST_P192_DIGITS 3
#define ECC_CURVE_NIST_P256_DIGITS 4
#define ECC_MAX_DIGITS (512 / 64)
#define ECC_DIGITS_TO_BYTES_SHIFT 3
/**
* struct ecc_point - elliptic curve point in affine coordinates
*
* @x: X coordinate in vli form.
* @y: Y coordinate in vli form.
* @ndigits: Length of vlis in u64 qwords.
*/
struct ecc_point {
u64 *x;
u64 *y;
u8 ndigits;
};
#define ECC_POINT_INIT(x, y, ndigits) (struct ecc_point) { x, y, ndigits }
/**
* struct ecc_curve - definition of elliptic curve
*
* @name: Short name of the curve.
* @g: Generator point of the curve.
* @p: Prime number, if Barrett's reduction is used for this curve
* pre-calculated value 'mu' is appended to the @p after ndigits.
* Use of Barrett's reduction is heuristically determined in
* vli_mmod_fast().
* @n: Order of the curve group.
* @a: Curve parameter a.
* @b: Curve parameter b.
*/
struct ecc_curve {
char *name;
struct ecc_point g;
u64 *p;
u64 *n;
u64 *a;
u64 *b;
};
/**
* 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