5279ef5769
With the allocations and BN_CTX gone, ECDH and point2oct are much, much shorter. Bug: 242 Change-Id: I3421822e94100f7eb2f5f2373df7fb3b3311365e Reviewed-on: https://boringssl-review.googlesource.com/c/33071 Commit-Queue: David Benjamin <davidben@google.com> CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org> Reviewed-by: Adam Langley <agl@google.com>
125 lines
4.6 KiB
C
125 lines
4.6 KiB
C
/* ====================================================================
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* Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED.
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*
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* The Elliptic Curve Public-Key Crypto Library (ECC Code) included
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* herein is developed by SUN MICROSYSTEMS, INC., and is contributed
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* to the OpenSSL project.
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*
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* The ECC Code is licensed pursuant to the OpenSSL open source
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* license provided below.
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*
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* The ECDH software is originally written by Douglas Stebila of
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* Sun Microsystems Laboratories.
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*
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*/
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/* ====================================================================
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* Copyright (c) 2000-2002 The OpenSSL Project. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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*
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in
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* the documentation and/or other materials provided with the
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* distribution.
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*
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* 3. All advertising materials mentioning features or use of this
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* software must display the following acknowledgment:
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* "This product includes software developed by the OpenSSL Project
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* for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
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*
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* 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
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* endorse or promote products derived from this software without
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* prior written permission. For written permission, please contact
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* licensing@OpenSSL.org.
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*
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* 5. Products derived from this software may not be called "OpenSSL"
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* nor may "OpenSSL" appear in their names without prior written
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* permission of the OpenSSL Project.
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*
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* 6. Redistributions of any form whatsoever must retain the following
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* acknowledgment:
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* "This product includes software developed by the OpenSSL Project
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* for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
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*
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* THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
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* EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
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* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
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* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
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* OF THE POSSIBILITY OF SUCH DAMAGE.
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* ====================================================================
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*
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* This product includes cryptographic software written by Eric Young
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* (eay@cryptsoft.com). This product includes software written by Tim
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* Hudson (tjh@cryptsoft.com). */
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#include <openssl/ecdh.h>
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#include <limits.h>
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#include <string.h>
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#include <openssl/digest.h>
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#include <openssl/err.h>
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#include <openssl/mem.h>
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#include "../fipsmodule/ec/internal.h"
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#include "../internal.h"
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int ECDH_compute_key(void *out, size_t out_len, const EC_POINT *pub_key,
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const EC_KEY *priv_key,
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void *(*kdf)(const void *in, size_t inlen, void *out,
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size_t *out_len)) {
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if (priv_key->priv_key == NULL) {
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OPENSSL_PUT_ERROR(ECDH, ECDH_R_NO_PRIVATE_VALUE);
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return -1;
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}
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const EC_SCALAR *const priv = &priv_key->priv_key->scalar;
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const EC_GROUP *const group = EC_KEY_get0_group(priv_key);
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if (EC_GROUP_cmp(group, pub_key->group, NULL) != 0) {
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OPENSSL_PUT_ERROR(EC, EC_R_INCOMPATIBLE_OBJECTS);
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return -1;
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}
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EC_RAW_POINT shared_point;
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uint8_t buf[EC_MAX_BYTES];
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size_t buf_len;
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if (!ec_point_mul_scalar(group, &shared_point, NULL, &pub_key->raw, priv) ||
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!ec_point_get_affine_coordinate_bytes(group, buf, NULL, &buf_len,
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sizeof(buf), &shared_point)) {
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OPENSSL_PUT_ERROR(ECDH, ECDH_R_POINT_ARITHMETIC_FAILURE);
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return -1;
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}
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if (kdf != NULL) {
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if (kdf(buf, buf_len, out, &out_len) == NULL) {
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OPENSSL_PUT_ERROR(ECDH, ECDH_R_KDF_FAILED);
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return -1;
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}
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} else {
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// no KDF, just copy as much as we can
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if (buf_len < out_len) {
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out_len = buf_len;
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}
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OPENSSL_memcpy(out, buf, out_len);
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}
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if (out_len > INT_MAX) {
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OPENSSL_PUT_ERROR(ECDH, ERR_R_OVERFLOW);
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return -1;
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}
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return (int)out_len;
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}
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