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 29 #define ECC_CURVE_NIST_P192_DIGITS 3 30 #define ECC_CURVE_NIST_P256_DIGITS 4 31 #define ECC_MAX_DIGITS ECC_CURVE_NIST_P256_DIGITS 32 33 #define ECC_DIGITS_TO_BYTES_SHIFT 3 34 35 /** 36 * ecc_is_key_valid() - Validate a given ECDH private key 37 * 38 * @curve_id: id representing the curve to use 39 * @ndigits: curve's number of digits 40 * @private_key: private key to be used for the given curve 41 * @private_key_len: private key length 42 * 43 * Returns 0 if the key is acceptable, a negative value otherwise 44 */ 45 int ecc_is_key_valid(unsigned int curve_id, unsigned int ndigits, 46 const u64 *private_key, unsigned int private_key_len); 47 48 /** 49 * ecc_gen_privkey() - Generates an ECC private key. 50 * The private key is a random integer in the range 0 < random < n, where n is a 51 * prime that is the order of the cyclic subgroup generated by the distinguished 52 * point G. 53 * @curve_id: id representing the curve to use 54 * @ndigits: curve number of digits 55 * @private_key: buffer for storing the generated private key 56 * 57 * Returns 0 if the private key was generated successfully, a negative value 58 * if an error occurred. 59 */ 60 int ecc_gen_privkey(unsigned int curve_id, unsigned int ndigits, u64 *privkey); 61 62 /** 63 * ecc_make_pub_key() - Compute an ECC public key 64 * 65 * @curve_id: id representing the curve to use 66 * @ndigits: curve's number of digits 67 * @private_key: pregenerated private key for the given curve 68 * @public_key: buffer for storing the generated public key 69 * 70 * Returns 0 if the public key was generated successfully, a negative value 71 * if an error occurred. 72 */ 73 int ecc_make_pub_key(const unsigned int curve_id, unsigned int ndigits, 74 const u64 *private_key, u64 *public_key); 75 76 /** 77 * crypto_ecdh_shared_secret() - Compute a shared secret 78 * 79 * @curve_id: id representing the curve to use 80 * @ndigits: curve's number of digits 81 * @private_key: private key of part A 82 * @public_key: public key of counterpart B 83 * @secret: buffer for storing the calculated shared secret 84 * 85 * Note: It is recommended that you hash the result of crypto_ecdh_shared_secret 86 * before using it for symmetric encryption or HMAC. 87 * 88 * Returns 0 if the shared secret was generated successfully, a negative value 89 * if an error occurred. 90 */ 91 int crypto_ecdh_shared_secret(unsigned int curve_id, unsigned int ndigits, 92 const u64 *private_key, const u64 *public_key, 93 u64 *secret); 94 #endif 95