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/*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
* ANY EXPRESS 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 COPYRIGHT OWNER OR 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.
*/
#include "ecdsa.h"
#include "utils.h"
#include <string.h>
#include "ec_ossl.h"
#include <openssl/evp.h>
#include <openssl/err.h>
#include <openssl/ec.h>
namespace pgp {
namespace ecdsa {
static bool
decode_sig(const uint8_t *data, size_t len, ec::Signature &sig)
{
rnp::ossl::ECDSASig esig(d2i_ECDSA_SIG(NULL, &data, len));
if (!esig.get()) {
RNP_LOG("Failed to parse ECDSA sig: %lu", ERR_peek_last_error());
return false;
}
rnp::bn r, s;
ECDSA_SIG_get0(esig.get(), r.cptr(), s.cptr());
r.mpi(sig.r);
s.mpi(sig.s);
return true;
}
static bool
encode_sig(uint8_t *data, size_t *len, const ec::Signature &sig)
{
ECDSA_SIG *dsig = ECDSA_SIG_new();
rnp::bn r(sig.r);
rnp::bn s(sig.s);
if (!dsig || !r || !s) {
RNP_LOG("Allocation failed.");
ECDSA_SIG_free(dsig);
return false;
}
ECDSA_SIG_set0(dsig, r.own(), s.own());
int outlen = i2d_ECDSA_SIG(dsig, &data);
ECDSA_SIG_free(dsig);
if (outlen < 0) {
RNP_LOG("Failed to encode signature.");
return false;
}
*len = outlen;
return true;
}
rnp_result_t
validate_key(rnp::RNG &rng, const ec::Key &key, bool secret)
{
return ec::validate_key(key, secret);
}
rnp_result_t
sign(rnp::RNG & rng,
ec::Signature & sig,
pgp_hash_alg_t hash_alg,
const rnp::secure_bytes &hash,
const ec::Key & key)
{
if (!key.x.size()) {
RNP_LOG("private key not set");
return RNP_ERROR_BAD_PARAMETERS;
}
/* Load secret key to DSA structure*/
auto evpkey = ec::load_key(key.p, &key.x, key.curve);
if (!evpkey) {
RNP_LOG("Failed to load key");
return RNP_ERROR_BAD_PARAMETERS;
}
/* init context and sign */
rnp::ossl::evp::PKeyCtx ctx(EVP_PKEY_CTX_new(evpkey.get(), NULL));
if (!ctx) {
RNP_LOG("Context allocation failed: %lu", ERR_peek_last_error());
return RNP_ERROR_GENERIC;
}
if (EVP_PKEY_sign_init(ctx.get()) <= 0) {
RNP_LOG("Failed to initialize signing: %lu", ERR_peek_last_error());
return RNP_ERROR_GENERIC;
}
/* DER encoded {r, s} pair, 16 bytes of overhead is enough */
std::vector<uint8_t> dersig(2 * MAX_CURVE_BYTELEN + 16, 0);
size_t siglen = dersig.size();
if (EVP_PKEY_sign(ctx.get(), dersig.data(), &siglen, hash.data(), hash.size()) <= 0) {
RNP_LOG("Signing failed: %lu", ERR_peek_last_error());
return RNP_ERROR_GENERIC;
}
if (!decode_sig(dersig.data(), siglen, sig)) {
RNP_LOG("Failed to parse ECDSA sig: %lu", ERR_peek_last_error());
return RNP_ERROR_GENERIC;
}
return RNP_SUCCESS;
}
rnp_result_t
verify(const ec::Signature & sig,
pgp_hash_alg_t hash_alg,
const rnp::secure_bytes &hash,
const ec::Key & key)
{
/* Load secret key to DSA structure*/
auto evpkey = ec::load_key(key.p, NULL, key.curve);
if (!evpkey) {
RNP_LOG("Failed to load key");
return RNP_ERROR_BAD_PARAMETERS;
}
/* init context and sign */
rnp::ossl::evp::PKeyCtx ctx(EVP_PKEY_CTX_new(evpkey.get(), NULL));
if (!ctx) {
RNP_LOG("Context allocation failed: %lu", ERR_peek_last_error());
return RNP_ERROR_SIGNATURE_INVALID;
}
if (EVP_PKEY_verify_init(ctx.get()) <= 0) {
RNP_LOG("Failed to initialize verify: %lu", ERR_peek_last_error());
return RNP_ERROR_SIGNATURE_INVALID;
}
/* signature is two coordinates + DER encoding, 16 is safe enough */
std::vector<uint8_t> sigbuf(sig.r.size() + sig.s.size() + 16);
size_t siglen = sigbuf.size();
if (!encode_sig(sigbuf.data(), &siglen, sig)) {
return RNP_ERROR_SIGNATURE_INVALID;
}
if (EVP_PKEY_verify(ctx.get(), sigbuf.data(), siglen, hash.data(), hash.size()) < 1) {
return RNP_ERROR_SIGNATURE_INVALID;
}
return RNP_SUCCESS;
}
} // namespace ecdsa
} // namespace pgp