ref: 4010db3078491baf3cb0d3d4e3a60c0cea114471
dir: /third_party/boringssl/src/crypto/ecdh_extra/ecdh_extra.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) 2000-2002 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
* licensing@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 <openssl/ecdh.h>
#include <limits.h>
#include <string.h>
#include <openssl/digest.h>
#include <openssl/err.h>
#include <openssl/mem.h>
#include "../fipsmodule/ec/internal.h"
#include "../internal.h"
int ECDH_compute_key(void *out, size_t out_len, const EC_POINT *pub_key,
const EC_KEY *priv_key,
void *(*kdf)(const void *in, size_t inlen, void *out,
size_t *out_len)) {
if (priv_key->priv_key == NULL) {
OPENSSL_PUT_ERROR(ECDH, ECDH_R_NO_PRIVATE_VALUE);
return -1;
}
const EC_SCALAR *const priv = &priv_key->priv_key->scalar;
const EC_GROUP *const group = EC_KEY_get0_group(priv_key);
if (EC_GROUP_cmp(group, pub_key->group, NULL) != 0) {
OPENSSL_PUT_ERROR(EC, EC_R_INCOMPATIBLE_OBJECTS);
return -1;
}
EC_RAW_POINT shared_point;
uint8_t buf[EC_MAX_BYTES];
size_t buf_len;
if (!ec_point_mul_scalar(group, &shared_point, &pub_key->raw, priv) ||
!ec_get_x_coordinate_as_bytes(group, buf, &buf_len, sizeof(buf),
&shared_point)) {
OPENSSL_PUT_ERROR(ECDH, ECDH_R_POINT_ARITHMETIC_FAILURE);
return -1;
}
if (kdf != NULL) {
if (kdf(buf, buf_len, out, &out_len) == NULL) {
OPENSSL_PUT_ERROR(ECDH, ECDH_R_KDF_FAILED);
return -1;
}
} else {
// no KDF, just copy as much as we can
if (buf_len < out_len) {
out_len = buf_len;
}
OPENSSL_memcpy(out, buf, out_len);
}
if (out_len > INT_MAX) {
OPENSSL_PUT_ERROR(ECDH, ERR_R_OVERFLOW);
return -1;
}
return (int)out_len;
}