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- /*
- * 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
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