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_MAX_DIGITS 4 /* 256 */ 30 31 #define ECC_DIGITS_TO_BYTES_SHIFT 3 32 33 /** 34 * ecc_is_key_valid() - Validate a given ECDH private key 35 * 36 * @curve_id: id representing the curve to use 37 * @ndigits: curve number of digits 38 * @private_key: private key to be used for the given curve 39 * @private_key_len: private key len 40 * 41 * Returns 0 if the key is acceptable, a negative value otherwise 42 */ 43 int ecc_is_key_valid(unsigned int curve_id, unsigned int ndigits, 44 const u8 *private_key, unsigned int private_key_len); 45 46 /** 47 * ecdh_make_pub_key() - Compute an ECC public key 48 * 49 * @curve_id: id representing the curve to use 50 * @private_key: pregenerated private key for the given curve 51 * @private_key_len: length of private_key 52 * @public_key: buffer for storing the public key generated 53 * @public_key_len: length of the public_key buffer 54 * 55 * Returns 0 if the public key was generated successfully, a negative value 56 * if an error occurred. 57 */ 58 int ecdh_make_pub_key(const unsigned int curve_id, unsigned int ndigits, 59 const u8 *private_key, unsigned int private_key_len, 60 u8 *public_key, unsigned int public_key_len); 61 62 /** 63 * crypto_ecdh_shared_secret() - Compute a shared secret 64 * 65 * @curve_id: id representing the curve to use 66 * @private_key: private key of part A 67 * @private_key_len: length of private_key 68 * @public_key: public key of counterpart B 69 * @public_key_len: length of public_key 70 * @secret: buffer for storing the calculated shared secret 71 * @secret_len: length of the secret buffer 72 * 73 * Note: It is recommended that you hash the result of crypto_ecdh_shared_secret 74 * before using it for symmetric encryption or HMAC. 75 * 76 * Returns 0 if the shared secret was generated successfully, a negative value 77 * if an error occurred. 78 */ 79 int crypto_ecdh_shared_secret(unsigned int curve_id, unsigned int ndigits, 80 const u8 *private_key, unsigned int private_key_len, 81 const u8 *public_key, unsigned int public_key_len, 82 u8 *secret, unsigned int secret_len); 83 #endif 84