openssl/crypto/sm2/sm2_pmeth.c
Matt Caswell d689f313cc Validate the SM2 digest len before use
Fixes a Coverity complaint.

Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/7170)
2018-09-10 17:28:33 +01:00

326 lines
7.8 KiB
C

/*
* Copyright 2006-2018 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the OpenSSL license (the "License"). You may not use
* this file except in compliance with the License. You can obtain a copy
* in the file LICENSE in the source distribution or at
* https://www.openssl.org/source/license.html
*/
#include "internal/cryptlib.h"
#include <openssl/asn1t.h>
#include <openssl/ec.h>
#include <openssl/evp.h>
#include "internal/evp_int.h"
#include "internal/sm2.h"
#include "internal/sm2err.h"
/* EC pkey context structure */
typedef struct {
/* Key and paramgen group */
EC_GROUP *gen_group;
/* message digest */
const EVP_MD *md;
/* Distinguishing Identifier, ISO/IEC 15946-3 */
uint8_t *id;
size_t id_len;
/* id_set indicates if the 'id' field is set (1) or not (0) */
int id_set;
} SM2_PKEY_CTX;
static int pkey_sm2_init(EVP_PKEY_CTX *ctx)
{
SM2_PKEY_CTX *smctx;
if ((smctx = OPENSSL_zalloc(sizeof(*smctx))) == NULL) {
SM2err(SM2_F_PKEY_SM2_INIT, ERR_R_MALLOC_FAILURE);
return 0;
}
ctx->data = smctx;
return 1;
}
static void pkey_sm2_cleanup(EVP_PKEY_CTX *ctx)
{
SM2_PKEY_CTX *smctx = ctx->data;
if (smctx != NULL) {
EC_GROUP_free(smctx->gen_group);
OPENSSL_free(smctx->id);
OPENSSL_free(smctx);
ctx->data = NULL;
}
}
static int pkey_sm2_copy(EVP_PKEY_CTX *dst, EVP_PKEY_CTX *src)
{
SM2_PKEY_CTX *dctx, *sctx;
if (!pkey_sm2_init(dst))
return 0;
sctx = src->data;
dctx = dst->data;
if (sctx->gen_group != NULL) {
dctx->gen_group = EC_GROUP_dup(sctx->gen_group);
if (dctx->gen_group == NULL) {
pkey_sm2_cleanup(dst);
return 0;
}
}
if (sctx->id != NULL) {
dctx->id = OPENSSL_malloc(sctx->id_len);
if (dctx->id == NULL) {
SM2err(SM2_F_PKEY_SM2_COPY, ERR_R_MALLOC_FAILURE);
pkey_sm2_cleanup(dst);
return 0;
}
memcpy(dctx->id, sctx->id, sctx->id_len);
}
dctx->id_len = sctx->id_len;
dctx->id_set = sctx->id_set;
dctx->md = sctx->md;
return 1;
}
static int pkey_sm2_sign(EVP_PKEY_CTX *ctx, unsigned char *sig, size_t *siglen,
const unsigned char *tbs, size_t tbslen)
{
int ret;
unsigned int sltmp;
EC_KEY *ec = ctx->pkey->pkey.ec;
const int sig_sz = ECDSA_size(ctx->pkey->pkey.ec);
if (sig_sz <= 0) {
return 0;
}
if (sig == NULL) {
*siglen = (size_t)sig_sz;
return 1;
}
if (*siglen < (size_t)sig_sz) {
SM2err(SM2_F_PKEY_SM2_SIGN, SM2_R_BUFFER_TOO_SMALL);
return 0;
}
ret = sm2_sign(tbs, tbslen, sig, &sltmp, ec);
if (ret <= 0)
return ret;
*siglen = (size_t)sltmp;
return 1;
}
static int pkey_sm2_verify(EVP_PKEY_CTX *ctx,
const unsigned char *sig, size_t siglen,
const unsigned char *tbs, size_t tbslen)
{
EC_KEY *ec = ctx->pkey->pkey.ec;
return sm2_verify(tbs, tbslen, sig, siglen, ec);
}
static int pkey_sm2_encrypt(EVP_PKEY_CTX *ctx,
unsigned char *out, size_t *outlen,
const unsigned char *in, size_t inlen)
{
EC_KEY *ec = ctx->pkey->pkey.ec;
SM2_PKEY_CTX *dctx = ctx->data;
const EVP_MD *md = (dctx->md == NULL) ? EVP_sm3() : dctx->md;
if (out == NULL) {
if (!sm2_ciphertext_size(ec, md, inlen, outlen))
return -1;
else
return 1;
}
return sm2_encrypt(ec, md, in, inlen, out, outlen);
}
static int pkey_sm2_decrypt(EVP_PKEY_CTX *ctx,
unsigned char *out, size_t *outlen,
const unsigned char *in, size_t inlen)
{
EC_KEY *ec = ctx->pkey->pkey.ec;
SM2_PKEY_CTX *dctx = ctx->data;
const EVP_MD *md = (dctx->md == NULL) ? EVP_sm3() : dctx->md;
if (out == NULL) {
if (!sm2_plaintext_size(ec, md, inlen, outlen))
return -1;
else
return 1;
}
return sm2_decrypt(ec, md, in, inlen, out, outlen);
}
static int pkey_sm2_ctrl(EVP_PKEY_CTX *ctx, int type, int p1, void *p2)
{
SM2_PKEY_CTX *smctx = ctx->data;
EC_GROUP *group;
uint8_t *tmp_id;
switch (type) {
case EVP_PKEY_CTRL_EC_PARAMGEN_CURVE_NID:
group = EC_GROUP_new_by_curve_name(p1);
if (group == NULL) {
SM2err(SM2_F_PKEY_SM2_CTRL, SM2_R_INVALID_CURVE);
return 0;
}
EC_GROUP_free(smctx->gen_group);
smctx->gen_group = group;
return 1;
case EVP_PKEY_CTRL_EC_PARAM_ENC:
if (smctx->gen_group == NULL) {
SM2err(SM2_F_PKEY_SM2_CTRL, SM2_R_NO_PARAMETERS_SET);
return 0;
}
EC_GROUP_set_asn1_flag(smctx->gen_group, p1);
return 1;
case EVP_PKEY_CTRL_MD:
smctx->md = p2;
return 1;
case EVP_PKEY_CTRL_GET_MD:
*(const EVP_MD **)p2 = smctx->md;
return 1;
case EVP_PKEY_CTRL_SET1_ID:
if (p1 > 0) {
tmp_id = OPENSSL_malloc(p1);
if (tmp_id == NULL) {
SM2err(SM2_F_PKEY_SM2_CTRL, ERR_R_MALLOC_FAILURE);
return 0;
}
memcpy(tmp_id, p2, p1);
OPENSSL_free(smctx->id);
smctx->id = tmp_id;
} else {
/* set null-ID */
OPENSSL_free(smctx->id);
smctx->id = NULL;
}
smctx->id_len = (size_t)p1;
smctx->id_set = 1;
return 1;
case EVP_PKEY_CTRL_GET1_ID:
memcpy(p2, smctx->id, smctx->id_len);
return 1;
case EVP_PKEY_CTRL_GET1_ID_LEN:
*(size_t *)p2 = smctx->id_len;
return 1;
default:
return -2;
}
}
static int pkey_sm2_ctrl_str(EVP_PKEY_CTX *ctx,
const char *type, const char *value)
{
if (strcmp(type, "ec_paramgen_curve") == 0) {
int nid = NID_undef;
if (((nid = EC_curve_nist2nid(value)) == NID_undef)
&& ((nid = OBJ_sn2nid(value)) == NID_undef)
&& ((nid = OBJ_ln2nid(value)) == NID_undef)) {
SM2err(SM2_F_PKEY_SM2_CTRL_STR, SM2_R_INVALID_CURVE);
return 0;
}
return EVP_PKEY_CTX_set_ec_paramgen_curve_nid(ctx, nid);
} else if (strcmp(type, "ec_param_enc") == 0) {
int param_enc;
if (strcmp(value, "explicit") == 0)
param_enc = 0;
else if (strcmp(value, "named_curve") == 0)
param_enc = OPENSSL_EC_NAMED_CURVE;
else
return -2;
return EVP_PKEY_CTX_set_ec_param_enc(ctx, param_enc);
}
return -2;
}
static int pkey_sm2_digest_custom(EVP_PKEY_CTX *ctx, EVP_MD_CTX *mctx)
{
uint8_t z[EVP_MAX_MD_SIZE];
SM2_PKEY_CTX *smctx = ctx->data;
EC_KEY *ec = ctx->pkey->pkey.ec;
const EVP_MD *md = EVP_MD_CTX_md(mctx);
int mdlen = EVP_MD_size(md);
if (!smctx->id_set) {
/*
* An ID value must be set. The specifications are not clear whether a
* NULL is allowed. We only allow it if set explicitly for maximum
* flexibility.
*/
SM2err(SM2_F_PKEY_SM2_DIGEST_CUSTOM, SM2_R_ID_NOT_SET);
return 0;
}
if (mdlen < 0) {
SM2err(SM2_F_PKEY_SM2_DIGEST_CUSTOM, SM2_R_INVALID_DIGEST);
return 0;
}
/* get hashed prefix 'z' of tbs message */
if (!sm2_compute_z_digest(z, md, smctx->id, smctx->id_len, ec))
return 0;
return EVP_DigestUpdate(mctx, z, (size_t)mdlen);
}
const EVP_PKEY_METHOD sm2_pkey_meth = {
EVP_PKEY_SM2,
0,
pkey_sm2_init,
pkey_sm2_copy,
pkey_sm2_cleanup,
0,
0,
0,
0,
0,
pkey_sm2_sign,
0,
pkey_sm2_verify,
0, 0,
0, 0, 0, 0,
0,
pkey_sm2_encrypt,
0,
pkey_sm2_decrypt,
0,
0,
pkey_sm2_ctrl,
pkey_sm2_ctrl_str,
0, 0,
0, 0, 0,
pkey_sm2_digest_custom
};