blob: d7da650870d07d5fcce94a48e8d23acc23096e2a [file] [log] [blame]
// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "crypto/ec_signature_creator_impl.h"
#include <stddef.h>
#include <stdint.h>
#include "crypto/ec_private_key.h"
#include "crypto/openssl_util.h"
#include "third_party/boringssl/src/include/openssl/bn.h"
#include "third_party/boringssl/src/include/openssl/ec.h"
#include "third_party/boringssl/src/include/openssl/ecdsa.h"
#include "third_party/boringssl/src/include/openssl/evp.h"
#include "third_party/boringssl/src/include/openssl/sha.h"
namespace crypto {
ECSignatureCreatorImpl::ECSignatureCreatorImpl(ECPrivateKey* key)
: key_(key) {
EnsureOpenSSLInit();
}
ECSignatureCreatorImpl::~ECSignatureCreatorImpl() = default;
bool ECSignatureCreatorImpl::Sign(const uint8_t* data,
int data_len,
std::vector<uint8_t>* signature) {
OpenSSLErrStackTracer err_tracer(FROM_HERE);
bssl::ScopedEVP_MD_CTX ctx;
size_t sig_len = 0;
if (!ctx.get() ||
!EVP_DigestSignInit(ctx.get(), nullptr, EVP_sha256(), nullptr,
key_->key()) ||
!EVP_DigestSignUpdate(ctx.get(), data, data_len) ||
!EVP_DigestSignFinal(ctx.get(), nullptr, &sig_len)) {
return false;
}
signature->resize(sig_len);
if (!EVP_DigestSignFinal(ctx.get(), &signature->front(), &sig_len))
return false;
// NOTE: A call to EVP_DigestSignFinal() with a nullptr second parameter
// returns a maximum allocation size, while the call without a nullptr
// returns the real one, which may be smaller.
signature->resize(sig_len);
return true;
}
bool ECSignatureCreatorImpl::DecodeSignature(
const std::vector<uint8_t>& der_sig,
std::vector<uint8_t>* out_raw_sig) {
OpenSSLErrStackTracer err_tracer(FROM_HERE);
// Create ECDSA_SIG object from DER-encoded data.
bssl::UniquePtr<ECDSA_SIG> ecdsa_sig(
ECDSA_SIG_from_bytes(der_sig.data(), der_sig.size()));
if (!ecdsa_sig.get())
return false;
// The result is made of two 32-byte vectors.
const size_t kMaxBytesPerBN = 32;
std::vector<uint8_t> result(2 * kMaxBytesPerBN);
if (!BN_bn2bin_padded(&result[0], kMaxBytesPerBN, ecdsa_sig->r) ||
!BN_bn2bin_padded(&result[kMaxBytesPerBN], kMaxBytesPerBN,
ecdsa_sig->s)) {
return false;
}
out_raw_sig->swap(result);
return true;
}
} // namespace crypto