1 /* 2 * Copyright 2018 The OpenSSL Project Authors. All Rights Reserved. 3 * 4 * Licensed under the OpenSSL license (the "License"). You may not use 5 * this file except in compliance with the License. You can obtain a copy 6 * in the file LICENSE in the source distribution or at 7 * https://www.openssl.org/source/license.html 8 */ 9 10 /* Internal EC functions for other submodules: not for application use */ 11 12 #ifndef OSSL_CRYPTO_EC_H 13 # define OSSL_CRYPTO_EC_H 14 # include <openssl/opensslconf.h> 15 16 # ifndef OPENSSL_NO_EC 17 18 # include <openssl/ec.h> 19 20 /*- 21 * Computes the multiplicative inverse of x in the range 22 * [1,EC_GROUP::order), where EC_GROUP::order is the cardinality of the 23 * subgroup generated by the generator G: 24 * 25 * res := x^(-1) (mod EC_GROUP::order). 26 * 27 * This function expects the following two conditions to hold: 28 * - the EC_GROUP order is prime, and 29 * - x is included in the range [1, EC_GROUP::order). 30 * 31 * This function returns 1 on success, 0 on error. 32 * 33 * If the EC_GROUP order is even, this function explicitly returns 0 as 34 * an error. 35 * In case any of the two conditions stated above is not satisfied, 36 * the correctness of its output is not guaranteed, even if the return 37 * value could still be 1 (as primality testing and a conditional modular 38 * reduction round on the input can be omitted by the underlying 39 * implementations for better SCA properties on regular input values). 40 */ 41 __owur int ec_group_do_inverse_ord(const EC_GROUP *group, BIGNUM *res, 42 const BIGNUM *x, BN_CTX *ctx); 43 44 /*- 45 * ECDH Key Derivation Function as defined in ANSI X9.63 46 */ 47 int ecdh_KDF_X9_63(unsigned char *out, size_t outlen, 48 const unsigned char *Z, size_t Zlen, 49 const unsigned char *sinfo, size_t sinfolen, 50 const EVP_MD *md); 51 52 # endif /* OPENSSL_NO_EC */ 53 #endif 54