520 lines
12 KiB
C
Executable file
520 lines
12 KiB
C
Executable file
/* $OpenBSD: ec_pmeth.c,v 1.12 2019/09/09 18:06:25 jsing Exp $ */
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/* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
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* project 2006.
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*/
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/* ====================================================================
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* Copyright (c) 2006 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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*
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*/
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#include <stdio.h>
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#include <string.h>
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#include <openssl/asn1t.h>
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#include <openssl/ec.h>
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#include <openssl/ecdsa.h>
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#include <openssl/err.h>
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#include <openssl/evp.h>
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#include <openssl/x509.h>
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#include "ec_lcl.h"
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#include "ech_locl.h"
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#include "evp_locl.h"
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/* EC pkey context structure */
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typedef struct {
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/* Key and paramgen group */
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EC_GROUP *gen_group;
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/* message digest */
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const EVP_MD *md;
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/* Duplicate key if custom cofactor needed */
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EC_KEY *co_key;
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/* Cofactor mode */
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signed char cofactor_mode;
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/* KDF (if any) to use for ECDH */
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char kdf_type;
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/* Message digest to use for key derivation */
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const EVP_MD *kdf_md;
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/* User key material */
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unsigned char *kdf_ukm;
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size_t kdf_ukmlen;
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/* KDF output length */
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size_t kdf_outlen;
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} EC_PKEY_CTX;
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static int
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pkey_ec_init(EVP_PKEY_CTX * ctx)
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{
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EC_PKEY_CTX *dctx;
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if ((dctx = calloc(1, sizeof(EC_PKEY_CTX))) == NULL) {
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ECerror(ERR_R_MALLOC_FAILURE);
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return 0;
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}
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dctx->cofactor_mode = -1;
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dctx->kdf_type = EVP_PKEY_ECDH_KDF_NONE;
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ctx->data = dctx;
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return 1;
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}
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static int
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pkey_ec_copy(EVP_PKEY_CTX * dst, EVP_PKEY_CTX * src)
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{
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EC_PKEY_CTX *dctx, *sctx;
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if (!pkey_ec_init(dst))
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return 0;
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sctx = src->data;
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dctx = dst->data;
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if (sctx->gen_group) {
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dctx->gen_group = EC_GROUP_dup(sctx->gen_group);
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if (!dctx->gen_group)
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return 0;
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}
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dctx->md = sctx->md;
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if (sctx->co_key) {
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dctx->co_key = EC_KEY_dup(sctx->co_key);
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if (!dctx->co_key)
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return 0;
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}
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dctx->kdf_type = sctx->kdf_type;
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dctx->kdf_md = sctx->kdf_md;
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dctx->kdf_outlen = sctx->kdf_outlen;
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if (sctx->kdf_ukm) {
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if ((dctx->kdf_ukm = calloc(1, sctx->kdf_ukmlen)) == NULL)
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return 0;
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memcpy(dctx->kdf_ukm, sctx->kdf_ukm, sctx->kdf_ukmlen);
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} else
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dctx->kdf_ukm = NULL;
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dctx->kdf_ukmlen = sctx->kdf_ukmlen;
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return 1;
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}
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static void
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pkey_ec_cleanup(EVP_PKEY_CTX * ctx)
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{
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EC_PKEY_CTX *dctx = ctx->data;
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if (dctx != NULL) {
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EC_GROUP_free(dctx->gen_group);
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EC_KEY_free(dctx->co_key);
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free(dctx->kdf_ukm);
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free(dctx);
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ctx->data = NULL;
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}
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}
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static int
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pkey_ec_sign(EVP_PKEY_CTX * ctx, unsigned char *sig, size_t * siglen,
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const unsigned char *tbs, size_t tbslen)
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{
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int ret, type;
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unsigned int sltmp;
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EC_PKEY_CTX *dctx = ctx->data;
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EC_KEY *ec = ctx->pkey->pkey.ec;
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if (!sig) {
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*siglen = ECDSA_size(ec);
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return 1;
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} else if (*siglen < (size_t) ECDSA_size(ec)) {
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ECerror(EC_R_BUFFER_TOO_SMALL);
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return 0;
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}
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if (dctx->md)
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type = EVP_MD_type(dctx->md);
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else
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type = NID_sha1;
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ret = ECDSA_sign(type, tbs, tbslen, sig, &sltmp, ec);
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if (ret <= 0)
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return ret;
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*siglen = (size_t) sltmp;
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return 1;
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}
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static int
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pkey_ec_verify(EVP_PKEY_CTX * ctx,
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const unsigned char *sig, size_t siglen,
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const unsigned char *tbs, size_t tbslen)
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{
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int ret, type;
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EC_PKEY_CTX *dctx = ctx->data;
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EC_KEY *ec = ctx->pkey->pkey.ec;
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if (dctx->md)
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type = EVP_MD_type(dctx->md);
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else
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type = NID_sha1;
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ret = ECDSA_verify(type, tbs, tbslen, sig, siglen, ec);
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return ret;
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}
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static int
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pkey_ec_derive(EVP_PKEY_CTX * ctx, unsigned char *key, size_t * keylen)
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{
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int ret;
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size_t outlen;
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const EC_POINT *pubkey = NULL;
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EC_KEY *eckey;
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EC_PKEY_CTX *dctx = ctx->data;
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if (!ctx->pkey || !ctx->peerkey) {
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ECerror(EC_R_KEYS_NOT_SET);
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return 0;
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}
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eckey = dctx->co_key ? dctx->co_key : ctx->pkey->pkey.ec;
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if (!key) {
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const EC_GROUP *group;
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group = EC_KEY_get0_group(eckey);
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*keylen = (EC_GROUP_get_degree(group) + 7) / 8;
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return 1;
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}
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pubkey = EC_KEY_get0_public_key(ctx->peerkey->pkey.ec);
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/*
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* NB: unlike PKCS#3 DH, if *outlen is less than maximum size this is
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* not an error, the result is truncated.
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*/
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outlen = *keylen;
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ret = ECDH_compute_key(key, outlen, pubkey, eckey, 0);
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if (ret <= 0)
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return 0;
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*keylen = ret;
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return 1;
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}
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static int
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pkey_ec_kdf_derive(EVP_PKEY_CTX *ctx, unsigned char *key, size_t *keylen)
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{
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EC_PKEY_CTX *dctx = ctx->data;
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unsigned char *ktmp = NULL;
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size_t ktmplen;
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int rv = 0;
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if (dctx->kdf_type == EVP_PKEY_ECDH_KDF_NONE)
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return pkey_ec_derive(ctx, key, keylen);
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if (!key) {
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*keylen = dctx->kdf_outlen;
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return 1;
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}
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if (*keylen != dctx->kdf_outlen)
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return 0;
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if (!pkey_ec_derive(ctx, NULL, &ktmplen))
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return 0;
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if ((ktmp = calloc(1, ktmplen)) == NULL) {
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ECerror(ERR_R_MALLOC_FAILURE);
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return 0;
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}
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if (!pkey_ec_derive(ctx, ktmp, &ktmplen))
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goto err;
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/* Do KDF stuff */
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if (!ecdh_KDF_X9_63(key, *keylen, ktmp, ktmplen, dctx->kdf_ukm,
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dctx->kdf_ukmlen, dctx->kdf_md))
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goto err;
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rv = 1;
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err:
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freezero(ktmp, ktmplen);
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return rv;
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}
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static int
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pkey_ec_ctrl(EVP_PKEY_CTX * ctx, int type, int p1, void *p2)
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{
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EC_PKEY_CTX *dctx = ctx->data;
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EC_GROUP *group;
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switch (type) {
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case EVP_PKEY_CTRL_EC_PARAMGEN_CURVE_NID:
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group = EC_GROUP_new_by_curve_name(p1);
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if (group == NULL) {
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ECerror(EC_R_INVALID_CURVE);
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return 0;
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}
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EC_GROUP_free(dctx->gen_group);
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dctx->gen_group = group;
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return 1;
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case EVP_PKEY_CTRL_EC_PARAM_ENC:
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if (!dctx->gen_group) {
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ECerror(EC_R_NO_PARAMETERS_SET);
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return 0;
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}
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EC_GROUP_set_asn1_flag(dctx->gen_group, p1);
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return 1;
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case EVP_PKEY_CTRL_EC_ECDH_COFACTOR:
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if (p1 == -2) {
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if (dctx->cofactor_mode != -1)
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return dctx->cofactor_mode;
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else {
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EC_KEY *ec_key = ctx->pkey->pkey.ec;
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return EC_KEY_get_flags(ec_key) & EC_FLAG_COFACTOR_ECDH ? 1 : 0;
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}
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} else if (p1 < -1 || p1 > 1)
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return -2;
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dctx->cofactor_mode = p1;
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if (p1 != -1) {
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EC_KEY *ec_key = ctx->pkey->pkey.ec;
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if (!ec_key->group)
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return -2;
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/* If cofactor is 1 cofactor mode does nothing */
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if (BN_is_one(&ec_key->group->cofactor))
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return 1;
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if (!dctx->co_key) {
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dctx->co_key = EC_KEY_dup(ec_key);
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if (!dctx->co_key)
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return 0;
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}
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if (p1)
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EC_KEY_set_flags(dctx->co_key, EC_FLAG_COFACTOR_ECDH);
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else
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EC_KEY_clear_flags(dctx->co_key, EC_FLAG_COFACTOR_ECDH);
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} else {
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EC_KEY_free(dctx->co_key);
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dctx->co_key = NULL;
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}
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return 1;
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case EVP_PKEY_CTRL_EC_KDF_TYPE:
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if (p1 == -2)
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return dctx->kdf_type;
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if (p1 != EVP_PKEY_ECDH_KDF_NONE && p1 != EVP_PKEY_ECDH_KDF_X9_63)
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return -2;
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dctx->kdf_type = p1;
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return 1;
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case EVP_PKEY_CTRL_EC_KDF_MD:
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dctx->kdf_md = p2;
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return 1;
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case EVP_PKEY_CTRL_GET_EC_KDF_MD:
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*(const EVP_MD **)p2 = dctx->kdf_md;
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return 1;
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case EVP_PKEY_CTRL_EC_KDF_OUTLEN:
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if (p1 <= 0)
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return -2;
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dctx->kdf_outlen = (size_t)p1;
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return 1;
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case EVP_PKEY_CTRL_GET_EC_KDF_OUTLEN:
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*(int *)p2 = dctx->kdf_outlen;
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return 1;
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case EVP_PKEY_CTRL_EC_KDF_UKM:
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free(dctx->kdf_ukm);
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dctx->kdf_ukm = p2;
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if (p2)
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dctx->kdf_ukmlen = p1;
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else
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dctx->kdf_ukmlen = 0;
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return 1;
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case EVP_PKEY_CTRL_GET_EC_KDF_UKM:
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*(unsigned char **)p2 = dctx->kdf_ukm;
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return dctx->kdf_ukmlen;
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case EVP_PKEY_CTRL_MD:
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if (EVP_MD_type((const EVP_MD *) p2) != NID_sha1 &&
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EVP_MD_type((const EVP_MD *) p2) != NID_ecdsa_with_SHA1 &&
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EVP_MD_type((const EVP_MD *) p2) != NID_sha224 &&
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EVP_MD_type((const EVP_MD *) p2) != NID_sha256 &&
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EVP_MD_type((const EVP_MD *) p2) != NID_sha384 &&
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EVP_MD_type((const EVP_MD *) p2) != NID_sha512) {
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ECerror(EC_R_INVALID_DIGEST_TYPE);
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return 0;
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}
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dctx->md = p2;
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return 1;
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case EVP_PKEY_CTRL_GET_MD:
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*(const EVP_MD **)p2 = dctx->md;
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return 1;
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case EVP_PKEY_CTRL_PEER_KEY:
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/* Default behaviour is OK */
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case EVP_PKEY_CTRL_DIGESTINIT:
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case EVP_PKEY_CTRL_PKCS7_SIGN:
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case EVP_PKEY_CTRL_CMS_SIGN:
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return 1;
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default:
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return -2;
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}
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}
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static int
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pkey_ec_ctrl_str(EVP_PKEY_CTX * ctx, const char *type, const char *value)
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{
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if (!strcmp(type, "ec_paramgen_curve")) {
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int nid;
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nid = EC_curve_nist2nid(value);
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if (nid == NID_undef)
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nid = OBJ_sn2nid(value);
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if (nid == NID_undef)
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nid = OBJ_ln2nid(value);
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if (nid == NID_undef) {
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ECerror(EC_R_INVALID_CURVE);
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return 0;
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}
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return EVP_PKEY_CTX_set_ec_paramgen_curve_nid(ctx, nid);
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} else if (strcmp(type, "ec_param_enc") == 0) {
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int param_enc;
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if (strcmp(value, "explicit") == 0)
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param_enc = 0;
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else if (strcmp(value, "named_curve") == 0)
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param_enc = OPENSSL_EC_NAMED_CURVE;
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else
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return -2;
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return EVP_PKEY_CTX_set_ec_param_enc(ctx, param_enc);
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} else if (strcmp(type, "ecdh_kdf_md") == 0) {
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const EVP_MD *md;
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if ((md = EVP_get_digestbyname(value)) == NULL) {
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ECerror(EC_R_INVALID_DIGEST);
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return 0;
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}
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return EVP_PKEY_CTX_set_ecdh_kdf_md(ctx, md);
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} else if (strcmp(type, "ecdh_cofactor_mode") == 0) {
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int co_mode;
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co_mode = atoi(value);
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return EVP_PKEY_CTX_set_ecdh_cofactor_mode(ctx, co_mode);
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}
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return -2;
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}
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static int
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pkey_ec_paramgen(EVP_PKEY_CTX * ctx, EVP_PKEY * pkey)
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{
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EC_KEY *ec = NULL;
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EC_PKEY_CTX *dctx = ctx->data;
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int ret = 0;
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if (dctx->gen_group == NULL) {
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ECerror(EC_R_NO_PARAMETERS_SET);
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return 0;
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}
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ec = EC_KEY_new();
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if (!ec)
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return 0;
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ret = EC_KEY_set_group(ec, dctx->gen_group);
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if (ret)
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EVP_PKEY_assign_EC_KEY(pkey, ec);
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else
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EC_KEY_free(ec);
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return ret;
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}
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static int
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pkey_ec_keygen(EVP_PKEY_CTX * ctx, EVP_PKEY * pkey)
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{
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EC_KEY *ec = NULL;
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EC_PKEY_CTX *dctx = ctx->data;
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if (ctx->pkey == NULL && dctx->gen_group == NULL) {
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ECerror(EC_R_NO_PARAMETERS_SET);
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return 0;
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}
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ec = EC_KEY_new();
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if (ec == NULL)
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return 0;
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if (!EVP_PKEY_assign_EC_KEY(pkey, ec)) {
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EC_KEY_free(ec);
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return 0;
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}
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/* Note: if error is returned, we count on caller to free pkey->pkey.ec */
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if (ctx->pkey != NULL) {
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if (!EVP_PKEY_copy_parameters(pkey, ctx->pkey))
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return 0;
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} else {
|
|
if (!EC_KEY_set_group(ec, dctx->gen_group))
|
|
return 0;
|
|
}
|
|
|
|
return EC_KEY_generate_key(ec);
|
|
}
|
|
|
|
const EVP_PKEY_METHOD ec_pkey_meth = {
|
|
.pkey_id = EVP_PKEY_EC,
|
|
|
|
.init = pkey_ec_init,
|
|
.copy = pkey_ec_copy,
|
|
.cleanup = pkey_ec_cleanup,
|
|
|
|
.paramgen = pkey_ec_paramgen,
|
|
|
|
.keygen = pkey_ec_keygen,
|
|
|
|
.sign = pkey_ec_sign,
|
|
|
|
.verify = pkey_ec_verify,
|
|
|
|
.derive = pkey_ec_kdf_derive,
|
|
|
|
.ctrl = pkey_ec_ctrl,
|
|
.ctrl_str = pkey_ec_ctrl_str
|
|
};
|