1a745d3acSDaniele Alessandrelli /* 2a745d3acSDaniele Alessandrelli * Copyright (c) 2013, Kenneth MacKay 3a745d3acSDaniele Alessandrelli * All rights reserved. 4a745d3acSDaniele Alessandrelli * 5a745d3acSDaniele Alessandrelli * Redistribution and use in source and binary forms, with or without 6a745d3acSDaniele Alessandrelli * modification, are permitted provided that the following conditions are 7a745d3acSDaniele Alessandrelli * met: 8a745d3acSDaniele Alessandrelli * * Redistributions of source code must retain the above copyright 9a745d3acSDaniele Alessandrelli * notice, this list of conditions and the following disclaimer. 10a745d3acSDaniele Alessandrelli * * Redistributions in binary form must reproduce the above copyright 11a745d3acSDaniele Alessandrelli * notice, this list of conditions and the following disclaimer in the 12a745d3acSDaniele Alessandrelli * documentation and/or other materials provided with the distribution. 13a745d3acSDaniele Alessandrelli * 14a745d3acSDaniele Alessandrelli * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 15a745d3acSDaniele Alessandrelli * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 16a745d3acSDaniele Alessandrelli * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 17a745d3acSDaniele Alessandrelli * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 18a745d3acSDaniele Alessandrelli * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 19a745d3acSDaniele Alessandrelli * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 20a745d3acSDaniele Alessandrelli * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 21a745d3acSDaniele Alessandrelli * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 22a745d3acSDaniele Alessandrelli * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 23a745d3acSDaniele Alessandrelli * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 24a745d3acSDaniele Alessandrelli * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 25a745d3acSDaniele Alessandrelli */ 26a745d3acSDaniele Alessandrelli #ifndef _CRYPTO_ECC_H 27a745d3acSDaniele Alessandrelli #define _CRYPTO_ECC_H 28a745d3acSDaniele Alessandrelli 29a745d3acSDaniele Alessandrelli #include <crypto/ecc_curve.h> 30a745d3acSDaniele Alessandrelli #include <asm/unaligned.h> 31a745d3acSDaniele Alessandrelli 32a745d3acSDaniele Alessandrelli /* One digit is u64 qword. */ 33a745d3acSDaniele Alessandrelli #define ECC_CURVE_NIST_P192_DIGITS 3 34a745d3acSDaniele Alessandrelli #define ECC_CURVE_NIST_P256_DIGITS 4 35a745d3acSDaniele Alessandrelli #define ECC_CURVE_NIST_P384_DIGITS 6 36a745d3acSDaniele Alessandrelli #define ECC_MAX_DIGITS (512 / 64) /* due to ecrdsa */ 37a745d3acSDaniele Alessandrelli 38a745d3acSDaniele Alessandrelli #define ECC_DIGITS_TO_BYTES_SHIFT 3 39a745d3acSDaniele Alessandrelli 40a745d3acSDaniele Alessandrelli #define ECC_MAX_BYTES (ECC_MAX_DIGITS << ECC_DIGITS_TO_BYTES_SHIFT) 41a745d3acSDaniele Alessandrelli 42a745d3acSDaniele Alessandrelli #define ECC_POINT_INIT(x, y, ndigits) (struct ecc_point) { x, y, ndigits } 43a745d3acSDaniele Alessandrelli 44a745d3acSDaniele Alessandrelli /** 45a745d3acSDaniele Alessandrelli * ecc_swap_digits() - Copy ndigits from big endian array to native array 46a745d3acSDaniele Alessandrelli * @in: Input array 47a745d3acSDaniele Alessandrelli * @out: Output array 48a745d3acSDaniele Alessandrelli * @ndigits: Number of digits to copy 49a745d3acSDaniele Alessandrelli */ 50a745d3acSDaniele Alessandrelli static inline void ecc_swap_digits(const void *in, u64 *out, unsigned int ndigits) 51a745d3acSDaniele Alessandrelli { 52a745d3acSDaniele Alessandrelli const __be64 *src = (__force __be64 *)in; 53a745d3acSDaniele Alessandrelli int i; 54a745d3acSDaniele Alessandrelli 55a745d3acSDaniele Alessandrelli for (i = 0; i < ndigits; i++) 56a745d3acSDaniele Alessandrelli out[i] = get_unaligned_be64(&src[ndigits - 1 - i]); 57a745d3acSDaniele Alessandrelli } 58a745d3acSDaniele Alessandrelli 59a745d3acSDaniele Alessandrelli /** 60*d67c96fbSStefan Berger * ecc_digits_from_bytes() - Create ndigits-sized digits array from byte array 61*d67c96fbSStefan Berger * @in: Input byte array 62*d67c96fbSStefan Berger * @nbytes Size of input byte array 63*d67c96fbSStefan Berger * @out Output digits array 64*d67c96fbSStefan Berger * @ndigits: Number of digits to create from byte array 65*d67c96fbSStefan Berger */ 66*d67c96fbSStefan Berger static inline void ecc_digits_from_bytes(const u8 *in, unsigned int nbytes, 67*d67c96fbSStefan Berger u64 *out, unsigned int ndigits) 68*d67c96fbSStefan Berger { 69*d67c96fbSStefan Berger unsigned int o = nbytes & 7; 70*d67c96fbSStefan Berger __be64 msd = 0; 71*d67c96fbSStefan Berger 72*d67c96fbSStefan Berger if (o) { 73*d67c96fbSStefan Berger memcpy((u8 *)&msd + sizeof(msd) - o, in, o); 74*d67c96fbSStefan Berger out[--ndigits] = be64_to_cpu(msd); 75*d67c96fbSStefan Berger in += o; 76*d67c96fbSStefan Berger } 77*d67c96fbSStefan Berger ecc_swap_digits(in, out, ndigits); 78*d67c96fbSStefan Berger } 79*d67c96fbSStefan Berger 80*d67c96fbSStefan Berger /** 81a745d3acSDaniele Alessandrelli * ecc_is_key_valid() - Validate a given ECDH private key 82a745d3acSDaniele Alessandrelli * 83a745d3acSDaniele Alessandrelli * @curve_id: id representing the curve to use 84a745d3acSDaniele Alessandrelli * @ndigits: curve's number of digits 85a745d3acSDaniele Alessandrelli * @private_key: private key to be used for the given curve 86a745d3acSDaniele Alessandrelli * @private_key_len: private key length 87a745d3acSDaniele Alessandrelli * 88a745d3acSDaniele Alessandrelli * Returns 0 if the key is acceptable, a negative value otherwise 89a745d3acSDaniele Alessandrelli */ 90a745d3acSDaniele Alessandrelli int ecc_is_key_valid(unsigned int curve_id, unsigned int ndigits, 91a745d3acSDaniele Alessandrelli const u64 *private_key, unsigned int private_key_len); 92a745d3acSDaniele Alessandrelli 93a745d3acSDaniele Alessandrelli /** 94a745d3acSDaniele Alessandrelli * ecc_gen_privkey() - Generates an ECC private key. 95a745d3acSDaniele Alessandrelli * The private key is a random integer in the range 0 < random < n, where n is a 96a745d3acSDaniele Alessandrelli * prime that is the order of the cyclic subgroup generated by the distinguished 97a745d3acSDaniele Alessandrelli * point G. 98a745d3acSDaniele Alessandrelli * @curve_id: id representing the curve to use 99a745d3acSDaniele Alessandrelli * @ndigits: curve number of digits 100a745d3acSDaniele Alessandrelli * @private_key: buffer for storing the generated private key 101a745d3acSDaniele Alessandrelli * 102a745d3acSDaniele Alessandrelli * Returns 0 if the private key was generated successfully, a negative value 103a745d3acSDaniele Alessandrelli * if an error occurred. 104a745d3acSDaniele Alessandrelli */ 105a745d3acSDaniele Alessandrelli int ecc_gen_privkey(unsigned int curve_id, unsigned int ndigits, u64 *privkey); 106a745d3acSDaniele Alessandrelli 107a745d3acSDaniele Alessandrelli /** 108a745d3acSDaniele Alessandrelli * ecc_make_pub_key() - Compute an ECC public key 109a745d3acSDaniele Alessandrelli * 110a745d3acSDaniele Alessandrelli * @curve_id: id representing the curve to use 111a745d3acSDaniele Alessandrelli * @ndigits: curve's number of digits 112a745d3acSDaniele Alessandrelli * @private_key: pregenerated private key for the given curve 113a745d3acSDaniele Alessandrelli * @public_key: buffer for storing the generated public key 114a745d3acSDaniele Alessandrelli * 115a745d3acSDaniele Alessandrelli * Returns 0 if the public key was generated successfully, a negative value 116a745d3acSDaniele Alessandrelli * if an error occurred. 117a745d3acSDaniele Alessandrelli */ 118a745d3acSDaniele Alessandrelli int ecc_make_pub_key(const unsigned int curve_id, unsigned int ndigits, 119a745d3acSDaniele Alessandrelli const u64 *private_key, u64 *public_key); 120a745d3acSDaniele Alessandrelli 121a745d3acSDaniele Alessandrelli /** 122a745d3acSDaniele Alessandrelli * crypto_ecdh_shared_secret() - Compute a shared secret 123a745d3acSDaniele Alessandrelli * 124a745d3acSDaniele Alessandrelli * @curve_id: id representing the curve to use 125a745d3acSDaniele Alessandrelli * @ndigits: curve's number of digits 126a745d3acSDaniele Alessandrelli * @private_key: private key of part A 127a745d3acSDaniele Alessandrelli * @public_key: public key of counterpart B 128a745d3acSDaniele Alessandrelli * @secret: buffer for storing the calculated shared secret 129a745d3acSDaniele Alessandrelli * 130a745d3acSDaniele Alessandrelli * Note: It is recommended that you hash the result of crypto_ecdh_shared_secret 131a745d3acSDaniele Alessandrelli * before using it for symmetric encryption or HMAC. 132a745d3acSDaniele Alessandrelli * 133a745d3acSDaniele Alessandrelli * Returns 0 if the shared secret was generated successfully, a negative value 134a745d3acSDaniele Alessandrelli * if an error occurred. 135a745d3acSDaniele Alessandrelli */ 136a745d3acSDaniele Alessandrelli int crypto_ecdh_shared_secret(unsigned int curve_id, unsigned int ndigits, 137a745d3acSDaniele Alessandrelli const u64 *private_key, const u64 *public_key, 138a745d3acSDaniele Alessandrelli u64 *secret); 139a745d3acSDaniele Alessandrelli 140a745d3acSDaniele Alessandrelli /** 141a745d3acSDaniele Alessandrelli * ecc_is_pubkey_valid_partial() - Partial public key validation 142a745d3acSDaniele Alessandrelli * 143a745d3acSDaniele Alessandrelli * @curve: elliptic curve domain parameters 144a745d3acSDaniele Alessandrelli * @pk: public key as a point 145a745d3acSDaniele Alessandrelli * 146a745d3acSDaniele Alessandrelli * Valdiate public key according to SP800-56A section 5.6.2.3.4 ECC Partial 147a745d3acSDaniele Alessandrelli * Public-Key Validation Routine. 148a745d3acSDaniele Alessandrelli * 149a745d3acSDaniele Alessandrelli * Note: There is no check that the public key is in the correct elliptic curve 150a745d3acSDaniele Alessandrelli * subgroup. 151a745d3acSDaniele Alessandrelli * 152a745d3acSDaniele Alessandrelli * Return: 0 if validation is successful, -EINVAL if validation is failed. 153a745d3acSDaniele Alessandrelli */ 154a745d3acSDaniele Alessandrelli int ecc_is_pubkey_valid_partial(const struct ecc_curve *curve, 155a745d3acSDaniele Alessandrelli struct ecc_point *pk); 156a745d3acSDaniele Alessandrelli 157a745d3acSDaniele Alessandrelli /** 158a745d3acSDaniele Alessandrelli * ecc_is_pubkey_valid_full() - Full public key validation 159a745d3acSDaniele Alessandrelli * 160a745d3acSDaniele Alessandrelli * @curve: elliptic curve domain parameters 161a745d3acSDaniele Alessandrelli * @pk: public key as a point 162a745d3acSDaniele Alessandrelli * 163a745d3acSDaniele Alessandrelli * Valdiate public key according to SP800-56A section 5.6.2.3.3 ECC Full 164a745d3acSDaniele Alessandrelli * Public-Key Validation Routine. 165a745d3acSDaniele Alessandrelli * 166a745d3acSDaniele Alessandrelli * Return: 0 if validation is successful, -EINVAL if validation is failed. 167a745d3acSDaniele Alessandrelli */ 168a745d3acSDaniele Alessandrelli int ecc_is_pubkey_valid_full(const struct ecc_curve *curve, 169a745d3acSDaniele Alessandrelli struct ecc_point *pk); 170a745d3acSDaniele Alessandrelli 171a745d3acSDaniele Alessandrelli /** 172a745d3acSDaniele Alessandrelli * vli_is_zero() - Determine is vli is zero 173a745d3acSDaniele Alessandrelli * 174a745d3acSDaniele Alessandrelli * @vli: vli to check. 175a745d3acSDaniele Alessandrelli * @ndigits: length of the @vli 176a745d3acSDaniele Alessandrelli */ 177a745d3acSDaniele Alessandrelli bool vli_is_zero(const u64 *vli, unsigned int ndigits); 178a745d3acSDaniele Alessandrelli 179a745d3acSDaniele Alessandrelli /** 180a745d3acSDaniele Alessandrelli * vli_cmp() - compare left and right vlis 181a745d3acSDaniele Alessandrelli * 182a745d3acSDaniele Alessandrelli * @left: vli 183a745d3acSDaniele Alessandrelli * @right: vli 184a745d3acSDaniele Alessandrelli * @ndigits: length of both vlis 185a745d3acSDaniele Alessandrelli * 186a745d3acSDaniele Alessandrelli * Returns sign of @left - @right, i.e. -1 if @left < @right, 187a745d3acSDaniele Alessandrelli * 0 if @left == @right, 1 if @left > @right. 188a745d3acSDaniele Alessandrelli */ 189a745d3acSDaniele Alessandrelli int vli_cmp(const u64 *left, const u64 *right, unsigned int ndigits); 190a745d3acSDaniele Alessandrelli 191a745d3acSDaniele Alessandrelli /** 192a745d3acSDaniele Alessandrelli * vli_sub() - Subtracts right from left 193a745d3acSDaniele Alessandrelli * 194a745d3acSDaniele Alessandrelli * @result: where to write result 195a745d3acSDaniele Alessandrelli * @left: vli 196a745d3acSDaniele Alessandrelli * @right vli 197a745d3acSDaniele Alessandrelli * @ndigits: length of all vlis 198a745d3acSDaniele Alessandrelli * 199a745d3acSDaniele Alessandrelli * Note: can modify in-place. 200a745d3acSDaniele Alessandrelli * 201a745d3acSDaniele Alessandrelli * Return: carry bit. 202a745d3acSDaniele Alessandrelli */ 203a745d3acSDaniele Alessandrelli u64 vli_sub(u64 *result, const u64 *left, const u64 *right, 204a745d3acSDaniele Alessandrelli unsigned int ndigits); 205a745d3acSDaniele Alessandrelli 206a745d3acSDaniele Alessandrelli /** 207a745d3acSDaniele Alessandrelli * vli_from_be64() - Load vli from big-endian u64 array 208a745d3acSDaniele Alessandrelli * 209a745d3acSDaniele Alessandrelli * @dest: destination vli 210a745d3acSDaniele Alessandrelli * @src: source array of u64 BE values 211a745d3acSDaniele Alessandrelli * @ndigits: length of both vli and array 212a745d3acSDaniele Alessandrelli */ 213a745d3acSDaniele Alessandrelli void vli_from_be64(u64 *dest, const void *src, unsigned int ndigits); 214a745d3acSDaniele Alessandrelli 215a745d3acSDaniele Alessandrelli /** 216a745d3acSDaniele Alessandrelli * vli_from_le64() - Load vli from little-endian u64 array 217a745d3acSDaniele Alessandrelli * 218a745d3acSDaniele Alessandrelli * @dest: destination vli 219a745d3acSDaniele Alessandrelli * @src: source array of u64 LE values 220a745d3acSDaniele Alessandrelli * @ndigits: length of both vli and array 221a745d3acSDaniele Alessandrelli */ 222a745d3acSDaniele Alessandrelli void vli_from_le64(u64 *dest, const void *src, unsigned int ndigits); 223a745d3acSDaniele Alessandrelli 224a745d3acSDaniele Alessandrelli /** 225a745d3acSDaniele Alessandrelli * vli_mod_inv() - Modular inversion 226a745d3acSDaniele Alessandrelli * 227a745d3acSDaniele Alessandrelli * @result: where to write vli number 228a745d3acSDaniele Alessandrelli * @input: vli value to operate on 229a745d3acSDaniele Alessandrelli * @mod: modulus 230a745d3acSDaniele Alessandrelli * @ndigits: length of all vlis 231a745d3acSDaniele Alessandrelli */ 232a745d3acSDaniele Alessandrelli void vli_mod_inv(u64 *result, const u64 *input, const u64 *mod, 233a745d3acSDaniele Alessandrelli unsigned int ndigits); 234a745d3acSDaniele Alessandrelli 235a745d3acSDaniele Alessandrelli /** 236a745d3acSDaniele Alessandrelli * vli_mod_mult_slow() - Modular multiplication 237a745d3acSDaniele Alessandrelli * 238a745d3acSDaniele Alessandrelli * @result: where to write result value 239a745d3acSDaniele Alessandrelli * @left: vli number to multiply with @right 240a745d3acSDaniele Alessandrelli * @right: vli number to multiply with @left 241a745d3acSDaniele Alessandrelli * @mod: modulus 242a745d3acSDaniele Alessandrelli * @ndigits: length of all vlis 243a745d3acSDaniele Alessandrelli * 244a745d3acSDaniele Alessandrelli * Note: Assumes that mod is big enough curve order. 245a745d3acSDaniele Alessandrelli */ 246a745d3acSDaniele Alessandrelli void vli_mod_mult_slow(u64 *result, const u64 *left, const u64 *right, 247a745d3acSDaniele Alessandrelli const u64 *mod, unsigned int ndigits); 248a745d3acSDaniele Alessandrelli 249a745d3acSDaniele Alessandrelli /** 250eaffe377SDaniele Alessandrelli * vli_num_bits() - Counts the number of bits required for vli. 251eaffe377SDaniele Alessandrelli * 252eaffe377SDaniele Alessandrelli * @vli: vli to check. 253eaffe377SDaniele Alessandrelli * @ndigits: Length of the @vli 254eaffe377SDaniele Alessandrelli * 255eaffe377SDaniele Alessandrelli * Return: The number of bits required to represent @vli. 256eaffe377SDaniele Alessandrelli */ 257eaffe377SDaniele Alessandrelli unsigned int vli_num_bits(const u64 *vli, unsigned int ndigits); 258eaffe377SDaniele Alessandrelli 259eaffe377SDaniele Alessandrelli /** 260eaffe377SDaniele Alessandrelli * ecc_aloc_point() - Allocate ECC point. 261eaffe377SDaniele Alessandrelli * 262eaffe377SDaniele Alessandrelli * @ndigits: Length of vlis in u64 qwords. 263eaffe377SDaniele Alessandrelli * 264eaffe377SDaniele Alessandrelli * Return: Pointer to the allocated point or NULL if allocation failed. 265eaffe377SDaniele Alessandrelli */ 266eaffe377SDaniele Alessandrelli struct ecc_point *ecc_alloc_point(unsigned int ndigits); 267eaffe377SDaniele Alessandrelli 268eaffe377SDaniele Alessandrelli /** 269eaffe377SDaniele Alessandrelli * ecc_free_point() - Free ECC point. 270eaffe377SDaniele Alessandrelli * 271eaffe377SDaniele Alessandrelli * @p: The point to free. 272eaffe377SDaniele Alessandrelli */ 273eaffe377SDaniele Alessandrelli void ecc_free_point(struct ecc_point *p); 274eaffe377SDaniele Alessandrelli 275eaffe377SDaniele Alessandrelli /** 276eaffe377SDaniele Alessandrelli * ecc_point_is_zero() - Check if point is zero. 277eaffe377SDaniele Alessandrelli * 278eaffe377SDaniele Alessandrelli * @p: Point to check for zero. 279eaffe377SDaniele Alessandrelli * 280eaffe377SDaniele Alessandrelli * Return: true if point is the point at infinity, false otherwise. 281eaffe377SDaniele Alessandrelli */ 282eaffe377SDaniele Alessandrelli bool ecc_point_is_zero(const struct ecc_point *point); 283eaffe377SDaniele Alessandrelli 284eaffe377SDaniele Alessandrelli /** 285a745d3acSDaniele Alessandrelli * ecc_point_mult_shamir() - Add two points multiplied by scalars 286a745d3acSDaniele Alessandrelli * 287a745d3acSDaniele Alessandrelli * @result: resulting point 288a745d3acSDaniele Alessandrelli * @x: scalar to multiply with @p 289a745d3acSDaniele Alessandrelli * @p: point to multiply with @x 290a745d3acSDaniele Alessandrelli * @y: scalar to multiply with @q 291a745d3acSDaniele Alessandrelli * @q: point to multiply with @y 292a745d3acSDaniele Alessandrelli * @curve: curve 293a745d3acSDaniele Alessandrelli * 294a745d3acSDaniele Alessandrelli * Returns result = x * p + x * q over the curve. 295a745d3acSDaniele Alessandrelli * This works faster than two multiplications and addition. 296a745d3acSDaniele Alessandrelli */ 297a745d3acSDaniele Alessandrelli void ecc_point_mult_shamir(const struct ecc_point *result, 298a745d3acSDaniele Alessandrelli const u64 *x, const struct ecc_point *p, 299a745d3acSDaniele Alessandrelli const u64 *y, const struct ecc_point *q, 300a745d3acSDaniele Alessandrelli const struct ecc_curve *curve); 301eaffe377SDaniele Alessandrelli 302a745d3acSDaniele Alessandrelli #endif 303