blob: 1341331f5841518da86c4b829362d20d6f4f1e54 [file] [log] [blame]
// Copyright (c) 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 <cstdint>
#include <string>
#include "absl/strings/string_view.h"
#include "openssl/base.h"
#include "quiche/quic/core/crypto/key_exchange.h"
#include "quiche/quic/platform/api/quic_export.h"
namespace quic {
// P256KeyExchange implements a SynchronousKeyExchange using elliptic-curve
// Diffie-Hellman on NIST P-256.
class QUIC_EXPORT_PRIVATE P256KeyExchange : public SynchronousKeyExchange {
~P256KeyExchange() override;
// New generates a private key and then creates new key-exchange object.
static std::unique_ptr<P256KeyExchange> New();
// New creates a new key-exchange object from a private key. If |private_key|
// is invalid, nullptr is returned.
static std::unique_ptr<P256KeyExchange> New(absl::string_view private_key);
// NewPrivateKey returns a private key, suitable for passing to |New|.
// If |NewPrivateKey| can't generate a private key, it returns an empty
// string.
static std::string NewPrivateKey();
// SynchronousKeyExchange interface.
bool CalculateSharedKeySync(absl::string_view peer_public_value,
std::string* shared_key) const override;
absl::string_view public_value() const override;
QuicTag type() const override { return kP256; }
enum {
// A P-256 field element consists of 32 bytes.
kP256FieldBytes = 32,
// A P-256 point in uncompressed form consists of 0x04 (to denote
// that the point is uncompressed) followed by two, 32-byte field
// elements.
kUncompressedP256PointBytes = 1 + 2 * kP256FieldBytes,
// The first byte in an uncompressed P-256 point.
kUncompressedECPointForm = 0x04,
// P256KeyExchange wraps |private_key|, and expects |public_key| consists of
// |kUncompressedP256PointBytes| bytes.
P256KeyExchange(bssl::UniquePtr<EC_KEY> private_key,
const uint8_t* public_key);
P256KeyExchange(const P256KeyExchange&) = delete;
P256KeyExchange& operator=(const P256KeyExchange&) = delete;
bssl::UniquePtr<EC_KEY> private_key_;
// The public key stored as an uncompressed P-256 point.
uint8_t public_key_[kUncompressedP256PointBytes];
} // namespace quic