| /* 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 <string.h> |
| #include <limits.h> |
| |
| #include "cryptlib.h" |
| |
| #include "ech_locl.h" |
| #include <openssl/err.h> |
| #include <openssl/sha.h> |
| #include <openssl/obj_mac.h> |
| #include <openssl/bn.h> |
| |
| 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, |
| #if 0 |
| NULL, /* init */ |
| NULL, /* finish */ |
| #endif |
| 0, /* 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 ((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: |
| if (tmp) |
| EC_POINT_free(tmp); |
| if (ctx) |
| BN_CTX_end(ctx); |
| if (ctx) |
| BN_CTX_free(ctx); |
| if (buf) |
| OPENSSL_free(buf); |
| return (ret); |
| } |
