| // 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. |
| |
| #ifndef NET_QUIC_CRYPTO_QUIC_DECRYPTER_H_ |
| #define NET_QUIC_CRYPTO_QUIC_DECRYPTER_H_ |
| |
| #include "net/base/net_export.h" |
| #include "net/quic/quic_protocol.h" |
| |
| namespace net { |
| |
| class NET_EXPORT_PRIVATE QuicDecrypter { |
| public: |
| virtual ~QuicDecrypter() {} |
| |
| static QuicDecrypter* Create(QuicTag algorithm); |
| |
| // Sets the encryption key. Returns true on success, false on failure. |
| // |
| // NOTE: The key is the client_write_key or server_write_key derived from |
| // the master secret. |
| virtual bool SetKey(base::StringPiece key) = 0; |
| |
| // Sets the fixed initial bytes of the nonce. Returns true on success, |
| // false on failure. |
| // |
| // NOTE: The nonce prefix is the client_write_iv or server_write_iv |
| // derived from the master secret. A 64-bit packet sequence number will |
| // be appended to form the nonce. |
| // |
| // <------------ 64 bits -----------> |
| // +---------------------+----------------------------------+ |
| // | Fixed prefix | Packet sequence number | |
| // +---------------------+----------------------------------+ |
| // Nonce format |
| // |
| // The security of the nonce format requires that QUIC never reuse a |
| // packet sequence number, even when retransmitting a lost packet. |
| virtual bool SetNoncePrefix(base::StringPiece nonce_prefix) = 0; |
| |
| // Decrypt authenticates |associated_data| and |ciphertext| and then decrypts |
| // |ciphertext| into |output|, using |nonce|. |nonce| must be 8 bytes longer |
| // than the nonce prefix length returned by GetNoncePrefixSize() (of the |
| // encrypter). |output| must be as long as |ciphertext| on entry and, on |
| // successful return, the true length of the plaintext will be written to |
| // |*output_length|. |
| virtual bool Decrypt(base::StringPiece nonce, |
| base::StringPiece associated_data, |
| base::StringPiece ciphertext, |
| unsigned char* output, |
| size_t* output_length) = 0; |
| |
| // Returns a newly created QuicData object containing the decrypted |
| // |ciphertext| or nullptr if there is an error. |sequence_number| is |
| // appended to the |nonce_prefix| value provided in SetNoncePrefix() |
| // to form the nonce. |
| // TODO(wtc): add a way for DecryptPacket to report decryption failure due |
| // to non-authentic inputs, as opposed to other reasons for failure. |
| virtual QuicData* DecryptPacket(QuicPacketSequenceNumber sequence_number, |
| base::StringPiece associated_data, |
| base::StringPiece ciphertext) = 0; |
| |
| // For use by unit tests only. |
| virtual base::StringPiece GetKey() const = 0; |
| virtual base::StringPiece GetNoncePrefix() const = 0; |
| }; |
| |
| } // namespace net |
| |
| #endif // NET_QUIC_CRYPTO_QUIC_DECRYPTER_H_ |