| // 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 "net/quic/crypto/null_decrypter.h" |
| |
| #include <stdint.h> |
| |
| #include "net/quic/quic_bug_tracker.h" |
| #include "net/quic/quic_data_reader.h" |
| #include "net/quic/quic_utils.h" |
| |
| using base::StringPiece; |
| using std::string; |
| |
| namespace net { |
| |
| NullDecrypter::NullDecrypter() {} |
| |
| bool NullDecrypter::SetKey(StringPiece key) { |
| return key.empty(); |
| } |
| |
| bool NullDecrypter::SetNoncePrefix(StringPiece nonce_prefix) { |
| return nonce_prefix.empty(); |
| } |
| |
| bool NullDecrypter::SetPreliminaryKey(StringPiece key) { |
| QUIC_BUG << "Should not be called"; |
| return false; |
| } |
| |
| bool NullDecrypter::SetDiversificationNonce(DiversificationNonce nonce) { |
| QUIC_BUG << "Should not be called"; |
| return true; |
| } |
| |
| bool NullDecrypter::DecryptPacket(QuicPathId /*path_id*/, |
| QuicPacketNumber /*packet_number*/, |
| StringPiece associated_data, |
| StringPiece ciphertext, |
| char* output, |
| size_t* output_length, |
| size_t max_output_length) { |
| QuicDataReader reader(ciphertext.data(), ciphertext.length()); |
| uint128 hash; |
| |
| if (!ReadHash(&reader, &hash)) { |
| return false; |
| } |
| |
| StringPiece plaintext = reader.ReadRemainingPayload(); |
| if (plaintext.length() > max_output_length) { |
| QUIC_BUG << "Output buffer must be larger than the plaintext."; |
| return false; |
| } |
| if (hash != ComputeHash(associated_data, plaintext)) { |
| return false; |
| } |
| // Copy the plaintext to output. |
| memcpy(output, plaintext.data(), plaintext.length()); |
| *output_length = plaintext.length(); |
| return true; |
| } |
| |
| StringPiece NullDecrypter::GetKey() const { |
| return StringPiece(); |
| } |
| |
| StringPiece NullDecrypter::GetNoncePrefix() const { |
| return StringPiece(); |
| } |
| |
| const char* NullDecrypter::cipher_name() const { |
| return "NULL"; |
| } |
| |
| uint32_t NullDecrypter::cipher_id() const { |
| return 0; |
| } |
| |
| bool NullDecrypter::ReadHash(QuicDataReader* reader, uint128* hash) { |
| uint64_t lo; |
| uint32_t hi; |
| if (!reader->ReadUInt64(&lo) || !reader->ReadUInt32(&hi)) { |
| return false; |
| } |
| *hash = hi; |
| *hash <<= 64; |
| *hash += lo; |
| return true; |
| } |
| |
| uint128 NullDecrypter::ComputeHash(const StringPiece data1, |
| const StringPiece data2) const { |
| uint128 correct_hash = QuicUtils::FNV1a_128_Hash_Two( |
| data1.data(), data1.length(), data2.data(), data2.length()); |
| uint128 mask(UINT64_C(0x0), UINT64_C(0xffffffff)); |
| mask <<= 96; |
| correct_hash &= ~mask; |
| return correct_hash; |
| } |
| |
| } // namespace net |