From 168e8374eeb7ae50816efcac23f65e7e1294360a Mon Sep 17 00:00:00 2001 From: "Dr. Stephen Henson" Date: Thu, 22 Oct 2015 18:35:56 +0100 Subject: move ECDH implementation to crypto/ec Reviewed-by: Richard Levitte --- crypto/ec/ecdh_ossl.c | 211 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 211 insertions(+) create mode 100644 crypto/ec/ecdh_ossl.c (limited to 'crypto/ec/ecdh_ossl.c') diff --git a/crypto/ec/ecdh_ossl.c b/crypto/ec/ecdh_ossl.c new file mode 100644 index 0000000000..ba66bd5af2 --- /dev/null +++ b/crypto/ec/ecdh_ossl.c @@ -0,0 +1,211 @@ +/* crypto/ecdh/ech_ossl.c */ +/* ==================================================================== + * Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED. + * + * The Elliptic Curve Public-Key Crypto Library (ECC Code) included + * herein is developed by SUN MICROSYSTEMS, INC., and is contributed + * to the OpenSSL project. + * + * The ECC Code is licensed pursuant to the OpenSSL open source + * license provided below. + * + * The ECDH software is originally written by Douglas Stebila of + * Sun Microsystems Laboratories. + * + */ +/* ==================================================================== + * Copyright (c) 1998-2003 The OpenSSL Project. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * + * 2. 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. + * + * 3. All advertising materials mentioning features or use of this + * software must display the following acknowledgment: + * "This product includes software developed by the OpenSSL Project + * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)" + * + * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to + * endorse or promote products derived from this software without + * prior written permission. For written permission, please contact + * openssl-core@OpenSSL.org. + * + * 5. Products derived from this software may not be called "OpenSSL" + * nor may "OpenSSL" appear in their names without prior written + * permission of the OpenSSL Project. + * + * 6. Redistributions of any form whatsoever must retain the following + * acknowledgment: + * "This product includes software developed by the OpenSSL Project + * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)" + * + * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY + * EXPRESSED 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 OpenSSL PROJECT OR + * ITS 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. + * ==================================================================== + * + * This product includes cryptographic software written by Eric Young + * (eay@cryptsoft.com). This product includes software written by Tim + * Hudson (tjh@cryptsoft.com). + * + */ + +#include +#include + +#include "internal/cryptlib.h" + +#include "ech_locl.h" +#include +#include +#include +#include + +static int ecdh_compute_key(void *out, size_t len, const EC_POINT *pub_key, + EC_KEY *ecdh, + void *(*KDF) (const void *in, size_t inlen, + void *out, size_t *outlen)); + +static ECDH_METHOD openssl_ecdh_meth = { + "OpenSSL ECDH method", + ecdh_compute_key, + ECDH_FLAG_FIPS_METHOD, /* flags */ + NULL /* app_data */ +}; + +const ECDH_METHOD *ECDH_OpenSSL(void) +{ + return &openssl_ecdh_meth; +} + +/*- + * This implementation is based on the following primitives in the IEEE 1363 standard: + * - ECKAS-DH1 + * - ECSVDP-DH + * Finally an optional KDF is applied. + */ +static int ecdh_compute_key(void *out, size_t outlen, const EC_POINT *pub_key, + EC_KEY *ecdh, + void *(*KDF) (const void *in, size_t inlen, + void *out, size_t *outlen)) +{ + BN_CTX *ctx; + EC_POINT *tmp = NULL; + BIGNUM *x = NULL, *y = NULL; + const BIGNUM *priv_key; + const EC_GROUP *group; + int ret = -1; + size_t buflen, len; + unsigned char *buf = NULL; + + if (outlen > INT_MAX) { + ECDHerr(ECDH_F_ECDH_COMPUTE_KEY, ERR_R_MALLOC_FAILURE); /* sort of, + * anyway */ + return -1; + } + + if ((ctx = BN_CTX_new()) == NULL) + goto err; + BN_CTX_start(ctx); + x = BN_CTX_get(ctx); + y = BN_CTX_get(ctx); + + priv_key = EC_KEY_get0_private_key(ecdh); + if (priv_key == NULL) { + ECDHerr(ECDH_F_ECDH_COMPUTE_KEY, ECDH_R_NO_PRIVATE_VALUE); + goto err; + } + + group = EC_KEY_get0_group(ecdh); + + if (EC_KEY_get_flags(ecdh) & EC_FLAG_COFACTOR_ECDH) { + if (!EC_GROUP_get_cofactor(group, x, ctx) || + !BN_mul(x, x, priv_key, ctx)) { + ECDHerr(ECDH_F_ECDH_COMPUTE_KEY, ERR_R_MALLOC_FAILURE); + goto err; + } + priv_key = x; + } + + if ((tmp = EC_POINT_new(group)) == NULL) { + ECDHerr(ECDH_F_ECDH_COMPUTE_KEY, ERR_R_MALLOC_FAILURE); + goto err; + } + + if (!EC_POINT_mul(group, tmp, NULL, pub_key, priv_key, ctx)) { + ECDHerr(ECDH_F_ECDH_COMPUTE_KEY, ECDH_R_POINT_ARITHMETIC_FAILURE); + goto err; + } + + if (EC_METHOD_get_field_type(EC_GROUP_method_of(group)) == + NID_X9_62_prime_field) { + if (!EC_POINT_get_affine_coordinates_GFp(group, tmp, x, y, ctx)) { + ECDHerr(ECDH_F_ECDH_COMPUTE_KEY, ECDH_R_POINT_ARITHMETIC_FAILURE); + goto err; + } + } +#ifndef OPENSSL_NO_EC2M + else { + if (!EC_POINT_get_affine_coordinates_GF2m(group, tmp, x, y, ctx)) { + ECDHerr(ECDH_F_ECDH_COMPUTE_KEY, ECDH_R_POINT_ARITHMETIC_FAILURE); + goto err; + } + } +#endif + + buflen = (EC_GROUP_get_degree(group) + 7) / 8; + len = BN_num_bytes(x); + if (len > buflen) { + ECDHerr(ECDH_F_ECDH_COMPUTE_KEY, ERR_R_INTERNAL_ERROR); + goto err; + } + if ((buf = OPENSSL_malloc(buflen)) == NULL) { + ECDHerr(ECDH_F_ECDH_COMPUTE_KEY, ERR_R_MALLOC_FAILURE); + goto err; + } + + memset(buf, 0, buflen - len); + if (len != (size_t)BN_bn2bin(x, buf + buflen - len)) { + ECDHerr(ECDH_F_ECDH_COMPUTE_KEY, ERR_R_BN_LIB); + goto err; + } + + if (KDF != 0) { + if (KDF(buf, buflen, out, &outlen) == NULL) { + ECDHerr(ECDH_F_ECDH_COMPUTE_KEY, ECDH_R_KDF_FAILED); + goto err; + } + ret = outlen; + } else { + /* no KDF, just copy as much as we can */ + if (outlen > buflen) + outlen = buflen; + memcpy(out, buf, outlen); + ret = outlen; + } + + err: + EC_POINT_free(tmp); + if (ctx) + BN_CTX_end(ctx); + BN_CTX_free(ctx); + OPENSSL_free(buf); + return (ret); +} -- cgit v1.2.3