boringssl/crypto/evp/p_ec.c
Adam Langley 95c29f3cd1 Inital import.
Initial fork from f2d678e6e89b6508147086610e985d4e8416e867 (1.0.2 beta).

(This change contains substantial changes from the original and
effectively starts a new history.)
2014-06-20 13:17:32 -07:00

424 lines
11 KiB
C

/* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
* project 2006.
*/
/* ====================================================================
* Copyright (c) 2006 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/evp.h>
#include <openssl/asn1.h>
#include <openssl/bn.h>
#include <openssl/buf.h>
#include <openssl/digest.h>
#include <openssl/ec.h>
#include <openssl/ec_key.h>
#include <openssl/ecdh.h>
#include <openssl/ecdsa.h>
#include <openssl/err.h>
#include <openssl/mem.h>
#include <openssl/obj.h>
#include "internal.h"
#include "../ec/internal.h"
typedef struct {
/* Key and paramgen group */
EC_GROUP *gen_group;
/* message digest */
const EVP_MD *md;
/* Duplicate key if custom cofactor needed */
EC_KEY *co_key;
/* Cofactor mode */
signed char cofactor_mode;
/* KDF (if any) to use for ECDH */
char kdf_type;
/* Message digest to use for key derivation */
const EVP_MD *kdf_md;
/* User key material */
unsigned char *kdf_ukm;
size_t kdf_ukmlen;
/* KDF output length */
size_t kdf_outlen;
} EC_PKEY_CTX;
static int pkey_ec_init(EVP_PKEY_CTX *ctx) {
EC_PKEY_CTX *dctx;
dctx = OPENSSL_malloc(sizeof(EC_PKEY_CTX));
if (!dctx) {
return 0;
}
memset(dctx, 0, sizeof(EC_PKEY_CTX));
dctx->cofactor_mode = -1;
dctx->kdf_type = EVP_PKEY_ECDH_KDF_NONE;
ctx->data = dctx;
return 1;
}
static int pkey_ec_copy(EVP_PKEY_CTX *dst, EVP_PKEY_CTX *src) {
EC_PKEY_CTX *dctx, *sctx;
if (!pkey_ec_init(dst)) {
return 0;
}
sctx = src->data;
dctx = dst->data;
if (sctx->gen_group) {
dctx->gen_group = EC_GROUP_dup(sctx->gen_group);
if (!dctx->gen_group) {
return 0;
}
}
dctx->md = sctx->md;
if (sctx->co_key) {
dctx->co_key = EC_KEY_dup(sctx->co_key);
if (!dctx->co_key) {
return 0;
}
}
dctx->kdf_type = sctx->kdf_type;
dctx->kdf_md = sctx->kdf_md;
dctx->kdf_outlen = sctx->kdf_outlen;
if (sctx->kdf_ukm) {
dctx->kdf_ukm = BUF_memdup(sctx->kdf_ukm, sctx->kdf_ukmlen);
if (!dctx->kdf_ukm) {
return 0;
}
} else {
dctx->kdf_ukm = NULL;
}
dctx->kdf_ukmlen = sctx->kdf_ukmlen;
return 1;
}
static void pkey_ec_cleanup(EVP_PKEY_CTX *ctx) {
EC_PKEY_CTX *dctx = ctx->data;
if (!dctx) {
return;
}
if (dctx->gen_group) {
EC_GROUP_free(dctx->gen_group);
}
if (dctx->co_key) {
EC_KEY_free(dctx->co_key);
}
if (dctx->kdf_ukm) {
OPENSSL_free(dctx->kdf_ukm);
}
OPENSSL_free(dctx);
}
static int pkey_ec_sign(EVP_PKEY_CTX *ctx, uint8_t *sig, size_t *siglen,
const uint8_t *tbs, size_t tbslen) {
int ret, type;
unsigned int sltmp;
EC_PKEY_CTX *dctx = ctx->data;
EC_KEY *ec = ctx->pkey->pkey.ec;
if (!sig) {
*siglen = ECDSA_size(ec);
return 1;
} else if (*siglen < (size_t)ECDSA_size(ec)) {
OPENSSL_PUT_ERROR(EVP, pkey_ec_sign, EVP_R_BUFFER_TOO_SMALL);
return 0;
}
type = NID_sha1;
if (dctx->md) {
type = EVP_MD_type(dctx->md);
}
ret = ECDSA_sign(type, tbs, tbslen, sig, &sltmp, ec);
if (ret <= 0) {
return ret;
}
*siglen = (size_t)sltmp;
return 1;
}
static int pkey_ec_verify(EVP_PKEY_CTX *ctx, const uint8_t *sig, size_t siglen,
const uint8_t *tbs, size_t tbslen) {
int type;
EC_PKEY_CTX *dctx = ctx->data;
EC_KEY *ec = ctx->pkey->pkey.ec;
type = NID_sha1;
if (dctx->md) {
type = EVP_MD_type(dctx->md);
}
return ECDSA_verify(type, tbs, tbslen, sig, siglen, ec);
}
static int pkey_ec_derive(EVP_PKEY_CTX *ctx, uint8_t *key,
size_t *keylen) {
int ret;
size_t outlen;
const EC_POINT *pubkey = NULL;
EC_KEY *eckey;
EC_PKEY_CTX *dctx = ctx->data;
if (!ctx->pkey || !ctx->peerkey) {
OPENSSL_PUT_ERROR(EVP, pkey_ec_derive, EVP_R_KEYS_NOT_SET);
return 0;
}
eckey = dctx->co_key ? dctx->co_key : ctx->pkey->pkey.ec;
if (!key) {
const EC_GROUP *group;
group = EC_KEY_get0_group(eckey);
*keylen = (EC_GROUP_get_degree(group) + 7) / 8;
return 1;
}
pubkey = EC_KEY_get0_public_key(ctx->peerkey->pkey.ec);
/* NB: unlike PKCS#3 DH, if *outlen is less than maximum size this is
* not an error, the result is truncated. */
outlen = *keylen;
ret = ECDH_compute_key(key, outlen, pubkey, eckey, 0);
if (ret < 0) {
return ret;
}
*keylen = ret;
return 1;
}
static int pkey_ec_kdf_derive(EVP_PKEY_CTX *ctx, uint8_t *key,
size_t *keylen) {
EC_PKEY_CTX *dctx = ctx->data;
uint8_t *ktmp = NULL;
size_t ktmplen;
int rv = 0;
if (dctx->kdf_type == EVP_PKEY_ECDH_KDF_NONE) {
return pkey_ec_derive(ctx, key, keylen);
}
if (!key) {
*keylen = dctx->kdf_outlen;
return 1;
}
if (*keylen != dctx->kdf_outlen ||
!pkey_ec_derive(ctx, NULL, &ktmplen)) {
return 0;
}
ktmp = OPENSSL_malloc(ktmplen);
if (!ktmp) {
return 0;
}
if (!pkey_ec_derive(ctx, ktmp, &ktmplen)) {
goto err;
}
if (!ECDH_KDF_X9_62(key, *keylen, ktmp, ktmplen, dctx->kdf_ukm,
dctx->kdf_ukmlen, dctx->kdf_md)) {
goto err;
}
rv = 1;
err:
if (ktmp) {
OPENSSL_cleanse(ktmp, ktmplen);
OPENSSL_free(ktmp);
}
return rv;
}
static int pkey_ec_ctrl(EVP_PKEY_CTX *ctx, int type, int p1, void *p2) {
EC_PKEY_CTX *dctx = ctx->data;
EC_GROUP *group;
switch (type) {
case EVP_PKEY_CTRL_EC_PARAMGEN_CURVE_NID:
group = EC_GROUP_new_by_curve_name(p1);
if (group == NULL) {
OPENSSL_PUT_ERROR(EVP, pkey_ec_ctrl, EVP_R_INVALID_CURVE);
return 0;
}
if (dctx->gen_group)
EC_GROUP_free(dctx->gen_group);
dctx->gen_group = group;
return 1;
case EVP_PKEY_CTRL_EC_KDF_TYPE:
if (p1 == -2)
return dctx->kdf_type;
if (p1 != EVP_PKEY_ECDH_KDF_NONE && p1 != EVP_PKEY_ECDH_KDF_X9_62)
return -2;
dctx->kdf_type = p1;
return 1;
case EVP_PKEY_CTRL_EC_KDF_MD:
dctx->kdf_md = p2;
return 1;
case EVP_PKEY_CTRL_GET_EC_KDF_MD:
*(const EVP_MD **)p2 = dctx->kdf_md;
return 1;
case EVP_PKEY_CTRL_EC_KDF_OUTLEN:
if (p1 <= 0)
return -2;
dctx->kdf_outlen = (size_t)p1;
return 1;
case EVP_PKEY_CTRL_GET_EC_KDF_OUTLEN:
*(int *)p2 = dctx->kdf_outlen;
return 1;
case EVP_PKEY_CTRL_EC_KDF_UKM:
if (dctx->kdf_ukm)
OPENSSL_free(dctx->kdf_ukm);
dctx->kdf_ukm = p2;
if (p2)
dctx->kdf_ukmlen = p1;
else
dctx->kdf_ukmlen = 0;
return 1;
case EVP_PKEY_CTRL_GET_EC_KDF_UKM:
*(unsigned char **)p2 = dctx->kdf_ukm;
return dctx->kdf_ukmlen;
case EVP_PKEY_CTRL_MD:
if (EVP_MD_type((const EVP_MD *)p2) != NID_sha1 &&
EVP_MD_type((const EVP_MD *)p2) != NID_ecdsa_with_SHA1 &&
EVP_MD_type((const EVP_MD *)p2) != NID_sha224 &&
EVP_MD_type((const EVP_MD *)p2) != NID_sha256 &&
EVP_MD_type((const EVP_MD *)p2) != NID_sha384 &&
EVP_MD_type((const EVP_MD *)p2) != NID_sha512) {
OPENSSL_PUT_ERROR(EVP, pkey_ec_ctrl, EVP_R_INVALID_DIGEST_TYPE);
return 0;
}
dctx->md = p2;
return 1;
case EVP_PKEY_CTRL_GET_MD:
*(const EVP_MD **)p2 = dctx->md;
return 1;
case EVP_PKEY_CTRL_PEER_KEY:
/* Default behaviour is OK */
case EVP_PKEY_CTRL_DIGESTINIT:
return 1;
default:
return -2;
}
}
static int pkey_ec_paramgen(EVP_PKEY_CTX *ctx, EVP_PKEY *pkey) {
EC_KEY *ec = NULL;
EC_PKEY_CTX *dctx = ctx->data;
int ret = 0;
if (dctx->gen_group == NULL) {
OPENSSL_PUT_ERROR(EVP, pkey_ec_paramgen, EVP_R_NO_PARAMETERS_SET);
return 0;
}
ec = EC_KEY_new();
if (!ec) {
return 0;
}
ret = EC_KEY_set_group(ec, dctx->gen_group);
if (ret) {
EVP_PKEY_assign_EC_KEY(pkey, ec);
} else {
EC_KEY_free(ec);
}
return ret;
}
static int pkey_ec_keygen(EVP_PKEY_CTX *ctx, EVP_PKEY *pkey) {
EC_KEY *ec = NULL;
EC_PKEY_CTX *dctx = ctx->data;
if (ctx->pkey == NULL && dctx->gen_group == NULL) {
OPENSSL_PUT_ERROR(EVP, pkey_ec_keygen, EVP_R_NO_PARAMETERS_SET);
return 0;
}
ec = EC_KEY_new();
if (!ec) {
return 0;
}
EVP_PKEY_assign_EC_KEY(pkey, ec);
if (ctx->pkey) {
/* Note: if error return, pkey is freed by parent routine */
if (!EVP_PKEY_copy_parameters(pkey, ctx->pkey)) {
return 0;
}
} else {
if (!EC_KEY_set_group(ec, dctx->gen_group)) {
return 0;
}
}
return EC_KEY_generate_key(pkey->pkey.ec);
}
const EVP_PKEY_METHOD ec_pkey_meth = {
EVP_PKEY_EC, 0 /* flags */, pkey_ec_init,
pkey_ec_copy, pkey_ec_cleanup, 0 /* paramgen_init */,
pkey_ec_paramgen, 0 /* keygen_init */, pkey_ec_keygen,
0 /* sign_init */, pkey_ec_sign, 0 /* verify_init */,
pkey_ec_verify, 0 /* signctx_init */, 0 /* signctx */,
0 /* verifyctx_init */, 0 /* verifyctx */, 0 /* encrypt_init */,
0 /* encrypt */, 0 /* decrypt_init */, 0 /* decrypt */,
0 /* derive_init */, pkey_ec_kdf_derive, pkey_ec_ctrl,
};