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// 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 <openssl/bytestring.h>
#include <openssl/ec.h>
#include <openssl/evp.h>
#include <openssl/mem.h>
#include <openssl/pkcs12.h>
#include <openssl/x509.h>
#include <stddef.h>
#include <stdint.h>
#include "base/logging.h"
#include "base/memory/scoped_ptr.h"
#include "crypto/auto_cbb.h"
#include "crypto/openssl_util.h"
#include "crypto/scoped_openssl_types.h"
namespace crypto {
namespace {
// Function pointer definition, for injecting the required key export function
// into ExportKeyWithBio, below. |bio| is a temporary memory BIO object, and
// |key| is a handle to the input key object. Return 1 on success, 0 otherwise.
// NOTE: Used with OpenSSL functions, which do not comply with the Chromium
// style guide, hence the unusual parameter placement / types.
typedef int (*ExportBioFunction)(BIO* bio, const void* key);
using ScopedPKCS8_PRIV_KEY_INFO =
ScopedOpenSSL<PKCS8_PRIV_KEY_INFO, PKCS8_PRIV_KEY_INFO_free>;
using ScopedX509_SIG = ScopedOpenSSL<X509_SIG, X509_SIG_free>;
// Helper to export |key| into |output| via the specified ExportBioFunction.
bool ExportKeyWithBio(const void* key,
ExportBioFunction export_fn,
std::vector<uint8_t>* output) {
if (!key)
return false;
ScopedBIO bio(BIO_new(BIO_s_mem()));
if (!bio.get())
return false;
if (!export_fn(bio.get(), key))
return false;
char* data = NULL;
long len = BIO_get_mem_data(bio.get(), &data);
if (!data || len < 0)
return false;
output->assign(data, data + len);
return true;
}
} // namespace
ECPrivateKey::~ECPrivateKey() {
if (key_)
EVP_PKEY_free(key_);
}
ECPrivateKey* ECPrivateKey::Copy() const {
scoped_ptr<ECPrivateKey> copy(new ECPrivateKey);
if (key_)
copy->key_ = EVP_PKEY_up_ref(key_);
return copy.release();
}
// static
ECPrivateKey* ECPrivateKey::Create() {
OpenSSLErrStackTracer err_tracer(FROM_HERE);
ScopedEC_KEY ec_key(EC_KEY_new_by_curve_name(NID_X9_62_prime256v1));
if (!ec_key.get() || !EC_KEY_generate_key(ec_key.get()))
return NULL;
scoped_ptr<ECPrivateKey> result(new ECPrivateKey());
result->key_ = EVP_PKEY_new();
if (!result->key_ || !EVP_PKEY_set1_EC_KEY(result->key_, ec_key.get()))
return NULL;
CHECK_EQ(EVP_PKEY_EC, EVP_PKEY_type(result->key_->type));
return result.release();
}
// static
ECPrivateKey* ECPrivateKey::CreateFromEncryptedPrivateKeyInfo(
const std::string& password,
const std::vector<uint8_t>& encrypted_private_key_info,
const std::vector<uint8_t>& subject_public_key_info) {
// NOTE: The |subject_public_key_info| can be ignored here, it is only
// useful for the NSS implementation (which uses the public key's SHA1
// as a lookup key when storing the private one in its store).
if (encrypted_private_key_info.empty())
return NULL;
OpenSSLErrStackTracer err_tracer(FROM_HERE);
const uint8_t* data = &encrypted_private_key_info[0];
const uint8_t* ptr = data;
ScopedX509_SIG p8_encrypted(
d2i_X509_SIG(NULL, &ptr, encrypted_private_key_info.size()));
if (!p8_encrypted || ptr != data + encrypted_private_key_info.size())
return NULL;
ScopedPKCS8_PRIV_KEY_INFO p8_decrypted;
if (password.empty()) {
// Hack for reading keys generated by an older version of the OpenSSL
// code. OpenSSL used to use "\0\0" rather than the empty string because it
// would treat the password as an ASCII string to be converted to UCS-2
// while NSS used a byte string.
p8_decrypted.reset(PKCS8_decrypt_pbe(
p8_encrypted.get(), reinterpret_cast<const uint8_t*>("\0\0"), 2));
}
if (!p8_decrypted) {
p8_decrypted.reset(PKCS8_decrypt_pbe(
p8_encrypted.get(),
reinterpret_cast<const uint8_t*>(password.data()),
password.size()));
}
if (!p8_decrypted)
return NULL;
// Create a new EVP_PKEY for it.
scoped_ptr<ECPrivateKey> result(new ECPrivateKey);
result->key_ = EVP_PKCS82PKEY(p8_decrypted.get());
if (!result->key_ || EVP_PKEY_type(result->key_->type) != EVP_PKEY_EC)
return NULL;
return result.release();
}
bool ECPrivateKey::ExportEncryptedPrivateKey(const std::string& password,
int iterations,
std::vector<uint8_t>* output) {
OpenSSLErrStackTracer err_tracer(FROM_HERE);
// Convert into a PKCS#8 object.
ScopedPKCS8_PRIV_KEY_INFO pkcs8(EVP_PKEY2PKCS8(key_));
if (!pkcs8.get())
return false;
// 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.
ScopedX509_SIG encrypted(PKCS8_encrypt_pbe(
NID_pbe_WithSHA1And3_Key_TripleDES_CBC,
nullptr,
reinterpret_cast<const uint8_t*>(password.data()),
password.size(),
nullptr,
0,
iterations,
pkcs8.get()));
if (!encrypted.get())
return false;
// Write it into |*output|
return ExportKeyWithBio(encrypted.get(),
reinterpret_cast<ExportBioFunction>(i2d_PKCS8_bio),
output);
}
bool ECPrivateKey::ExportPublicKey(std::vector<uint8_t>* output) {
OpenSSLErrStackTracer err_tracer(FROM_HERE);
uint8_t *der;
size_t der_len;
AutoCBB cbb;
if (!CBB_init(cbb.get(), 0) ||
!EVP_marshal_public_key(cbb.get(), key_) ||
!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) {
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_);
ScopedBIGNUM x(BN_new());
ScopedBIGNUM 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;
}
bool ECPrivateKey::ExportValueForTesting(std::vector<uint8_t>* output) {
OpenSSLErrStackTracer err_tracer(FROM_HERE);
EC_KEY* ec_key = EVP_PKEY_get0_EC_KEY(key_);
uint8_t *der;
size_t der_len;
AutoCBB cbb;
if (!CBB_init(cbb.get(), 0) ||
!EC_KEY_marshal_private_key(cbb.get(), ec_key, 0 /* enc_flags */) ||
!CBB_finish(cbb.get(), &der, &der_len)) {
return false;
}
output->assign(der, der + der_len);
OPENSSL_free(der);
return true;
}
ECPrivateKey::ECPrivateKey() : key_(NULL) {}
} // namespace crypto