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// Copyright 2013 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 "net/quic/test_tools/crypto_test_utils.h"
#include <openssl/bn.h>
#include <openssl/ec.h>
#include <openssl/ecdsa.h>
#include <openssl/evp.h>
#include <openssl/obj_mac.h>
#include <openssl/sha.h>
#include "crypto/openssl_util.h"
#include "crypto/secure_hash.h"
#include "net/quic/crypto/channel_id.h"
using base::StringPiece;
using std::string;
namespace {
void EvpMdCtxCleanUp(EVP_MD_CTX* ctx) {
(void)EVP_MD_CTX_cleanup(ctx);
}
} // namespace anonymous
namespace net {
namespace test {
class TestChannelIDSigner : public ChannelIDSigner {
public:
virtual ~TestChannelIDSigner() { }
// ChannelIDSigner implementation.
virtual bool Sign(const string& hostname,
StringPiece signed_data,
string* out_key,
string* out_signature) OVERRIDE {
crypto::ScopedOpenSSL<EVP_PKEY, EVP_PKEY_free> ecdsa_key(
HostnameToKey(hostname));
*out_key = SerializeKey(ecdsa_key.get());
if (out_key->empty()) {
return false;
}
EVP_MD_CTX md_ctx;
EVP_MD_CTX_init(&md_ctx);
crypto::ScopedOpenSSL<EVP_MD_CTX, EvpMdCtxCleanUp>
md_ctx_cleanup(&md_ctx);
if (EVP_DigestSignInit(&md_ctx, NULL, EVP_sha256(), NULL,
ecdsa_key.get()) != 1) {
return false;
}
EVP_DigestUpdate(&md_ctx, ChannelIDVerifier::kContextStr,
strlen(ChannelIDVerifier::kContextStr) + 1);
EVP_DigestUpdate(&md_ctx, ChannelIDVerifier::kClientToServerStr,
strlen(ChannelIDVerifier::kClientToServerStr) + 1);
EVP_DigestUpdate(&md_ctx, signed_data.data(), signed_data.size());
size_t sig_len;
if (!EVP_DigestSignFinal(&md_ctx, NULL, &sig_len)) {
return false;
}
scoped_ptr<uint8[]> der_sig(new uint8[sig_len]);
if (!EVP_DigestSignFinal(&md_ctx, der_sig.get(), &sig_len)) {
return false;
}
uint8* derp = der_sig.get();
crypto::ScopedOpenSSL<ECDSA_SIG, ECDSA_SIG_free> sig(
d2i_ECDSA_SIG(NULL, const_cast<const uint8**>(&derp), sig_len));
if (sig.get() == NULL) {
return false;
}
// The signature consists of a pair of 32-byte numbers.
static const size_t kSignatureLength = 32 * 2;
scoped_ptr<uint8[]> signature(new uint8[kSignatureLength]);
memset(signature.get(), 0, kSignatureLength);
BN_bn2bin(sig.get()->r, signature.get() + 32 - BN_num_bytes(sig.get()->r));
BN_bn2bin(sig.get()->s, signature.get() + 64 - BN_num_bytes(sig.get()->s));
*out_signature = string(reinterpret_cast<char*>(signature.get()),
kSignatureLength);
return true;
}
virtual string GetKeyForHostname(const string& hostname) OVERRIDE {
crypto::ScopedOpenSSL<EVP_PKEY, EVP_PKEY_free> ecdsa_key(
HostnameToKey(hostname));
return SerializeKey(ecdsa_key.get());
}
private:
static EVP_PKEY* HostnameToKey(const string& hostname) {
// In order to generate a deterministic key for a given hostname the
// hostname is hashed with SHA-256 and the resulting digest is treated as a
// big-endian number. The most-significant bit is cleared to ensure that
// the resulting value is less than the order of the group and then it's
// taken as a private key. Given the private key, the public key is
// calculated with a group multiplication.
SHA256_CTX sha256;
SHA256_Init(&sha256);
SHA256_Update(&sha256, hostname.data(), hostname.size());
unsigned char digest[SHA256_DIGEST_LENGTH];
SHA256_Final(digest, &sha256);
// Ensure that the digest is less than the order of the P-256 group by
// clearing the most-significant bit.
digest[0] &= 0x7f;
crypto::ScopedOpenSSL<BIGNUM, BN_free> k(BN_new());
CHECK(BN_bin2bn(digest, sizeof(digest), k.get()) != NULL);
crypto::ScopedOpenSSL<EC_GROUP, EC_GROUP_free> p256(
EC_GROUP_new_by_curve_name(NID_X9_62_prime256v1));
CHECK(p256.get());
crypto::ScopedOpenSSL<EC_KEY, EC_KEY_free> ecdsa_key(EC_KEY_new());
CHECK(ecdsa_key.get() != NULL &&
EC_KEY_set_group(ecdsa_key.get(), p256.get()));
crypto::ScopedOpenSSL<EC_POINT, EC_POINT_free> point(
EC_POINT_new(p256.get()));
CHECK(EC_POINT_mul(p256.get(), point.get(), k.get(), NULL, NULL, NULL));
EC_KEY_set_private_key(ecdsa_key.get(), k.get());
EC_KEY_set_public_key(ecdsa_key.get(), point.get());
crypto::ScopedOpenSSL<EVP_PKEY, EVP_PKEY_free> pkey(EVP_PKEY_new());
// EVP_PKEY_set1_EC_KEY takes a reference so no |release| here.
EVP_PKEY_set1_EC_KEY(pkey.get(), ecdsa_key.get());
return pkey.release();
}
static string SerializeKey(EVP_PKEY* key) {
// i2d_PublicKey will produce an ANSI X9.62 public key which, for a P-256
// key, is 0x04 (meaning uncompressed) followed by the x and y field
// elements as 32-byte, big-endian numbers.
static const int kExpectedKeyLength = 65;
int len = i2d_PublicKey(key, NULL);
if (len != kExpectedKeyLength) {
return "";
}
uint8 buf[kExpectedKeyLength];
uint8* derp = buf;
i2d_PublicKey(key, &derp);
return string(reinterpret_cast<char*>(buf + 1), kExpectedKeyLength - 1);
}
};
// static
ChannelIDSigner* CryptoTestUtils::ChannelIDSignerForTesting() {
return new TestChannelIDSigner();
}
} // namespace test
} // namespace net
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