1 // Copyright (c) 2013 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef NET_QUIC_CRYPTO_P256_KEY_EXCHANGE_H_ 6 #define NET_QUIC_CRYPTO_P256_KEY_EXCHANGE_H_ 7 8 #include <string> 9 10 #include "base/memory/scoped_ptr.h" 11 #include "base/strings/string_piece.h" 12 #include "net/base/net_export.h" 13 #include "net/quic/crypto/key_exchange.h" 14 15 #if defined(USE_OPENSSL) 16 #include "crypto/openssl_util.h" 17 // Forward declaration for openssl/*.h 18 typedef struct ec_key_st EC_KEY; 19 extern "C" void EC_KEY_free(EC_KEY* key); 20 #else 21 #include "crypto/ec_private_key.h" 22 #include "crypto/scoped_nss_types.h" 23 #endif 24 25 namespace net { 26 27 // P256KeyExchange implements a KeyExchange using elliptic-curve 28 // Diffie-Hellman on NIST P-256. 29 class NET_EXPORT_PRIVATE P256KeyExchange : public KeyExchange { 30 public: 31 virtual ~P256KeyExchange(); 32 33 // New creates a new key exchange object from a private key. If 34 // |private_key| is invalid, NULL is returned. 35 static P256KeyExchange* New(base::StringPiece private_key); 36 37 // |NewPrivateKey| returns a private key, suitable for passing to |New|. 38 // If |NewPrivateKey| can't generate a private key, it returns an empty 39 // string. 40 static std::string NewPrivateKey(); 41 42 // KeyExchange interface. 43 virtual KeyExchange* NewKeyPair(QuicRandom* rand) const OVERRIDE; 44 virtual bool CalculateSharedKey(const base::StringPiece& peer_public_value, 45 std::string* shared_key) const OVERRIDE; 46 virtual base::StringPiece public_value() const OVERRIDE; 47 virtual QuicTag tag() const OVERRIDE; 48 49 private: 50 enum { 51 // A P-256 field element consists of 32 bytes. 52 kP256FieldBytes = 32, 53 // A P-256 point in uncompressed form consists of 0x04 (to denote 54 // that the point is uncompressed) followed by two, 32-byte field 55 // elements. 56 kUncompressedP256PointBytes = 1 + 2 * kP256FieldBytes, 57 // The first byte in an uncompressed P-256 point. 58 kUncompressedECPointForm = 0x04, 59 }; 60 61 #if defined(USE_OPENSSL) 62 // P256KeyExchange takes ownership of |private_key|, and expects 63 // |public_key| consists of |kUncompressedP256PointBytes| bytes. 64 P256KeyExchange(EC_KEY* private_key, const uint8* public_key); 65 66 crypto::ScopedOpenSSL<EC_KEY, EC_KEY_free> private_key_; 67 #else 68 // P256KeyExchange takes ownership of |key_pair|, and expects 69 // |public_key| consists of |kUncompressedP256PointBytes| bytes. 70 P256KeyExchange(crypto::ECPrivateKey* key_pair, const uint8* public_key); 71 72 scoped_ptr<crypto::ECPrivateKey> key_pair_; 73 #endif 74 // The public key stored as an uncompressed P-256 point. 75 uint8 public_key_[kUncompressedP256PointBytes]; 76 77 DISALLOW_COPY_AND_ASSIGN(P256KeyExchange); 78 }; 79 80 } // namespace net 81 #endif // NET_QUIC_CRYPTO_P256_KEY_EXCHANGE_H_ 82 83
