blob: 28bbe3f3e09cb3f61e3cd327fe1d2fc3d7f5d9b1 [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_private_key.h"
#include <stddef.h>
#include <stdint.h>
#include <utility>
#include "base/check_op.h"
#include "crypto/openssl_util.h"
#include "third_party/boringssl/src/include/openssl/bn.h"
#include "third_party/boringssl/src/include/openssl/bytestring.h"
#include "third_party/boringssl/src/include/openssl/ec.h"
#include "third_party/boringssl/src/include/openssl/ec_key.h"
#include "third_party/boringssl/src/include/openssl/evp.h"
#include "third_party/boringssl/src/include/openssl/mem.h"
#include "third_party/boringssl/src/include/openssl/pkcs8.h"
namespace crypto {
ECPrivateKey::~ECPrivateKey() = default;
// static
std::unique_ptr<ECPrivateKey> ECPrivateKey::Create() {
OpenSSLErrStackTracer err_tracer(FROM_HERE);
bssl::UniquePtr<EC_KEY> ec_key(
EC_KEY_new_by_curve_name(NID_X9_62_prime256v1));
if (!ec_key || !EC_KEY_generate_key(ec_key.get()))
return nullptr;
std::unique_ptr<ECPrivateKey> result(new ECPrivateKey());
result->key_.reset(EVP_PKEY_new());
if (!result->key_ || !EVP_PKEY_set1_EC_KEY(result->key_.get(), ec_key.get()))
return nullptr;
CHECK_EQ(EVP_PKEY_EC, EVP_PKEY_id(result->key_.get()));
return result;
}
// static
std::unique_ptr<ECPrivateKey> ECPrivateKey::CreateFromPrivateKeyInfo(
base::span<const uint8_t> input) {
OpenSSLErrStackTracer err_tracer(FROM_HERE);
CBS cbs;
CBS_init(&cbs, input.data(), input.size());
bssl::UniquePtr<EVP_PKEY> pkey(EVP_parse_private_key(&cbs));
if (!pkey || CBS_len(&cbs) != 0 || EVP_PKEY_id(pkey.get()) != EVP_PKEY_EC)
return nullptr;
std::unique_ptr<ECPrivateKey> result(new ECPrivateKey());
result->key_ = std::move(pkey);
return result;
}
// static
std::unique_ptr<ECPrivateKey> ECPrivateKey::CreateFromEncryptedPrivateKeyInfo(
base::span<const uint8_t> encrypted_private_key_info) {
OpenSSLErrStackTracer err_tracer(FROM_HERE);
CBS cbs;
CBS_init(&cbs, encrypted_private_key_info.data(),
encrypted_private_key_info.size());
bssl::UniquePtr<EVP_PKEY> pkey(
PKCS8_parse_encrypted_private_key(&cbs, "", 0));
// Hack for reading keys generated by an older version of the OpenSSL code.
// Some implementations encode the empty password as "\0\0" (passwords are
// normally encoded in big-endian UCS-2 with a NUL terminator) and some
// encode as the empty string. PKCS8_parse_encrypted_private_key
// distinguishes the two by whether the password is nullptr.
if (!pkey) {
CBS_init(&cbs, encrypted_private_key_info.data(),
encrypted_private_key_info.size());
pkey.reset(PKCS8_parse_encrypted_private_key(&cbs, nullptr, 0));
}
if (!pkey || CBS_len(&cbs) != 0 || EVP_PKEY_id(pkey.get()) != EVP_PKEY_EC)
return nullptr;
std::unique_ptr<ECPrivateKey> result(new ECPrivateKey());
result->key_ = std::move(pkey);
return result;
}
// static
std::unique_ptr<ECPrivateKey> ECPrivateKey::DeriveFromSecret(
base::span<const uint8_t> secret) {
bssl::UniquePtr<EC_GROUP> group(
EC_GROUP_new_by_curve_name(NID_X9_62_prime256v1));
if (!group)
return nullptr;
bssl::UniquePtr<EC_KEY> ec_key(
EC_KEY_derive_from_secret(group.get(), secret.data(), secret.size()));
if (!ec_key)
return nullptr;
std::unique_ptr<ECPrivateKey> result(new ECPrivateKey());
result->key_.reset(EVP_PKEY_new());
if (!result->key_ || !EVP_PKEY_set1_EC_KEY(result->key_.get(), ec_key.get()))
return nullptr;
CHECK_EQ(EVP_PKEY_EC, EVP_PKEY_id(result->key_.get()));
return result;
}
std::unique_ptr<ECPrivateKey> ECPrivateKey::Copy() const {
std::unique_ptr<ECPrivateKey> copy(new ECPrivateKey());
copy->key_ = bssl::UpRef(key_);
return copy;
}
bool ECPrivateKey::ExportPrivateKey(std::vector<uint8_t>* output) const {
OpenSSLErrStackTracer err_tracer(FROM_HERE);
uint8_t* der;
size_t der_len;
bssl::ScopedCBB cbb;
if (!CBB_init(cbb.get(), 0) ||
!EVP_marshal_private_key(cbb.get(), key_.get()) ||
!CBB_finish(cbb.get(), &der, &der_len)) {
return false;
}
output->assign(der, der + der_len);
OPENSSL_free(der);
return true;
}
bool ECPrivateKey::ExportEncryptedPrivateKey(
std::vector<uint8_t>* output) const {
OpenSSLErrStackTracer err_tracer(FROM_HERE);
// Encrypt the object.
// NOTE: NSS uses SEC_OID_PKCS12_V2_PBE_WITH_SHA1_AND_3KEY_TRIPLE_DES_CBC
// so use NID_pbe_WithSHA1And3_Key_TripleDES_CBC which should be the OpenSSL
// equivalent.
uint8_t* der;
size_t der_len;
bssl::ScopedCBB cbb;
if (!CBB_init(cbb.get(), 0) ||
!PKCS8_marshal_encrypted_private_key(
cbb.get(), NID_pbe_WithSHA1And3_Key_TripleDES_CBC,
nullptr /* cipher */, nullptr /* no password */, 0 /* pass_len */,
nullptr /* salt */, 0 /* salt_len */, 1 /* iterations */,
key_.get()) ||
!CBB_finish(cbb.get(), &der, &der_len)) {
return false;
}
output->assign(der, der + der_len);
OPENSSL_free(der);
return true;
}
bool ECPrivateKey::ExportPublicKey(std::vector<uint8_t>* output) const {
OpenSSLErrStackTracer err_tracer(FROM_HERE);
uint8_t* der;
size_t der_len;
bssl::ScopedCBB cbb;
if (!CBB_init(cbb.get(), 0) ||
!EVP_marshal_public_key(cbb.get(), key_.get()) ||
!CBB_finish(cbb.get(), &der, &der_len)) {
return false;
}
output->assign(der, der + der_len);
OPENSSL_free(der);
return true;
}
bool ECPrivateKey::ExportRawPublicKey(std::string* output) const {
OpenSSLErrStackTracer err_tracer(FROM_HERE);
// Export the x and y field elements as 32-byte, big-endian numbers. (This is
// the same as X9.62 uncompressed form without the leading 0x04 byte.)
EC_KEY* ec_key = EVP_PKEY_get0_EC_KEY(key_.get());
bssl::UniquePtr<BIGNUM> x(BN_new());
bssl::UniquePtr<BIGNUM> y(BN_new());
uint8_t buf[64];
if (!x || !y ||
!EC_POINT_get_affine_coordinates_GFp(EC_KEY_get0_group(ec_key),
EC_KEY_get0_public_key(ec_key),
x.get(), y.get(), nullptr) ||
!BN_bn2bin_padded(buf, 32, x.get()) ||
!BN_bn2bin_padded(buf + 32, 32, y.get())) {
return false;
}
output->assign(reinterpret_cast<const char*>(buf), sizeof(buf));
return true;
}
ECPrivateKey::ECPrivateKey() = default;
} // namespace crypto