1 // Copyright (c) 2012 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.
5 #include "net/quic/crypto/null_decrypter.h"
6 #include "net/quic/quic_utils.h"
7 #include "net/quic/quic_data_reader.h"
9 using base::StringPiece;
14 NullDecrypter::NullDecrypter() {}
16 bool NullDecrypter::SetKey(StringPiece key) { return key.empty(); }
18 bool NullDecrypter::SetNoncePrefix(StringPiece nonce_prefix) {
19 return nonce_prefix.empty();
22 bool NullDecrypter::Decrypt(StringPiece /*nonce*/,
23 StringPiece associated_data,
24 StringPiece ciphertext,
25 unsigned char* output,
26 size_t* output_length) {
27 QuicDataReader reader(ciphertext.data(), ciphertext.length());
30 if (!ReadHash(&reader, &hash)) {
34 StringPiece plaintext = reader.ReadRemainingPayload();
36 // TODO(rch): avoid buffer copy here
37 string buffer = associated_data.as_string();
38 plaintext.AppendToString(&buffer);
39 if (hash != ComputeHash(buffer)) {
42 memcpy(output, plaintext.data(), plaintext.length());
43 *output_length = plaintext.length();
47 QuicData* NullDecrypter::DecryptPacket(QuicPacketSequenceNumber /*seq_number*/,
48 StringPiece associated_data,
49 StringPiece ciphertext) {
50 // It's worth duplicating |Decrypt|, above, in order to save a copy by using
51 // the shared-data QuicData constructor directly.
52 QuicDataReader reader(ciphertext.data(), ciphertext.length());
55 if (!ReadHash(&reader, &hash)) {
59 StringPiece plaintext = reader.ReadRemainingPayload();
61 // TODO(rch): avoid buffer copy here
62 string buffer = associated_data.as_string();
63 plaintext.AppendToString(&buffer);
65 if (hash != ComputeHash(buffer)) {
68 return new QuicData(plaintext.data(), plaintext.length());
71 StringPiece NullDecrypter::GetKey() const { return StringPiece(); }
73 StringPiece NullDecrypter::GetNoncePrefix() const { return StringPiece(); }
75 bool NullDecrypter::ReadHash(QuicDataReader* reader, uint128* hash) {
78 if (!reader->ReadUInt64(&lo) ||
79 !reader->ReadUInt32(&hi)) {
88 uint128 NullDecrypter::ComputeHash(const string& data) const {
89 uint128 correct_hash = QuicUtils::FNV1a_128_Hash(data.data(), data.length());
90 uint128 mask(GG_UINT64_C(0x0), GG_UINT64_C(0xffffffff));
92 correct_hash &= ~mask;