blob: af0c444769078405399cce712b7d4d530f8b8bfd [file] [log] [blame]
// 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 "quiche/quic/core/crypto/null_decrypter.h"
#include <cstdint>
#include "absl/numeric/int128.h"
#include "absl/strings/string_view.h"
#include "quiche/quic/core/quic_data_reader.h"
#include "quiche/quic/core/quic_utils.h"
#include "quiche/quic/platform/api/quic_bug_tracker.h"
#include "quiche/common/quiche_endian.h"
namespace quic {
NullDecrypter::NullDecrypter(Perspective perspective)
: perspective_(perspective) {}
bool NullDecrypter::SetKey(absl::string_view key) { return key.empty(); }
bool NullDecrypter::SetNoncePrefix(absl::string_view nonce_prefix) {
return nonce_prefix.empty();
}
bool NullDecrypter::SetIV(absl::string_view iv) { return iv.empty(); }
bool NullDecrypter::SetHeaderProtectionKey(absl::string_view key) {
return key.empty();
}
bool NullDecrypter::SetPreliminaryKey(absl::string_view /*key*/) {
QUIC_BUG(quic_bug_10652_1) << "Should not be called";
return false;
}
bool NullDecrypter::SetDiversificationNonce(
const DiversificationNonce& /*nonce*/) {
QUIC_BUG(quic_bug_10652_2) << "Should not be called";
return true;
}
bool NullDecrypter::DecryptPacket(uint64_t /*packet_number*/,
absl::string_view associated_data,
absl::string_view ciphertext, char* output,
size_t* output_length,
size_t max_output_length) {
QuicDataReader reader(ciphertext.data(), ciphertext.length(),
quiche::HOST_BYTE_ORDER);
absl::uint128 hash;
if (!ReadHash(&reader, &hash)) {
return false;
}
absl::string_view plaintext = reader.ReadRemainingPayload();
if (plaintext.length() > max_output_length) {
QUIC_BUG(quic_bug_10652_3)
<< "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;
}
std::string NullDecrypter::GenerateHeaderProtectionMask(
QuicDataReader* /*sample_reader*/) {
return std::string(5, 0);
}
size_t NullDecrypter::GetKeySize() const { return 0; }
size_t NullDecrypter::GetNoncePrefixSize() const { return 0; }
size_t NullDecrypter::GetIVSize() const { return 0; }
absl::string_view NullDecrypter::GetKey() const { return absl::string_view(); }
absl::string_view NullDecrypter::GetNoncePrefix() const {
return absl::string_view();
}
uint32_t NullDecrypter::cipher_id() const { return 0; }
QuicPacketCount NullDecrypter::GetIntegrityLimit() const {
return std::numeric_limits<QuicPacketCount>::max();
}
bool NullDecrypter::ReadHash(QuicDataReader* reader, absl::uint128* hash) {
uint64_t lo;
uint32_t hi;
if (!reader->ReadUInt64(&lo) || !reader->ReadUInt32(&hi)) {
return false;
}
*hash = absl::MakeUint128(hi, lo);
return true;
}
absl::uint128 NullDecrypter::ComputeHash(const absl::string_view data1,
const absl::string_view data2) const {
absl::uint128 correct_hash;
if (perspective_ == Perspective::IS_CLIENT) {
// Peer is a server.
correct_hash = QuicUtils::FNV1a_128_Hash_Three(data1, data2, "Server");
} else {
// Peer is a client.
correct_hash = QuicUtils::FNV1a_128_Hash_Three(data1, data2, "Client");
}
absl::uint128 mask = absl::MakeUint128(UINT64_C(0x0), UINT64_C(0xffffffff));
mask <<= 96;
correct_hash &= ~mask;
return correct_hash;
}
} // namespace quic