| // 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_encrypter.h" |
| |
| #include <algorithm> |
| #include <limits> |
| #include <string> |
| |
| #include "absl/numeric/int128.h" |
| #include "absl/strings/string_view.h" |
| #include "quiche/quic/core/quic_data_writer.h" |
| #include "quiche/quic/core/quic_utils.h" |
| |
| namespace quic { |
| |
| const size_t kHashSizeShort = 12; // size of uint128 serialized short |
| |
| NullEncrypter::NullEncrypter(Perspective perspective) |
| : perspective_(perspective) {} |
| |
| bool NullEncrypter::SetKey(absl::string_view key) { return key.empty(); } |
| |
| bool NullEncrypter::SetNoncePrefix(absl::string_view nonce_prefix) { |
| return nonce_prefix.empty(); |
| } |
| |
| bool NullEncrypter::SetIV(absl::string_view iv) { return iv.empty(); } |
| |
| bool NullEncrypter::SetHeaderProtectionKey(absl::string_view key) { |
| return key.empty(); |
| } |
| |
| bool NullEncrypter::EncryptPacket(uint64_t /*packet_number*/, |
| absl::string_view associated_data, |
| absl::string_view plaintext, char* output, |
| size_t* output_length, |
| size_t max_output_length) { |
| const size_t len = plaintext.size() + GetHashLength(); |
| if (max_output_length < len) { |
| return false; |
| } |
| absl::uint128 hash; |
| if (perspective_ == Perspective::IS_SERVER) { |
| hash = |
| QuicUtils::FNV1a_128_Hash_Three(associated_data, plaintext, "Server"); |
| } else { |
| hash = |
| QuicUtils::FNV1a_128_Hash_Three(associated_data, plaintext, "Client"); |
| } |
| // TODO(ianswett): memmove required for in place encryption. Placing the |
| // hash at the end would allow use of memcpy, doing nothing for in place. |
| memmove(output + GetHashLength(), plaintext.data(), plaintext.length()); |
| QuicUtils::SerializeUint128Short(hash, |
| reinterpret_cast<unsigned char*>(output)); |
| *output_length = len; |
| return true; |
| } |
| |
| std::string NullEncrypter::GenerateHeaderProtectionMask( |
| absl::string_view /*sample*/) { |
| return std::string(5, 0); |
| } |
| |
| size_t NullEncrypter::GetKeySize() const { return 0; } |
| |
| size_t NullEncrypter::GetNoncePrefixSize() const { return 0; } |
| |
| size_t NullEncrypter::GetIVSize() const { return 0; } |
| |
| size_t NullEncrypter::GetMaxPlaintextSize(size_t ciphertext_size) const { |
| return ciphertext_size - std::min(ciphertext_size, GetHashLength()); |
| } |
| |
| size_t NullEncrypter::GetCiphertextSize(size_t plaintext_size) const { |
| return plaintext_size + GetHashLength(); |
| } |
| |
| QuicPacketCount NullEncrypter::GetConfidentialityLimit() const { |
| return std::numeric_limits<QuicPacketCount>::max(); |
| } |
| |
| absl::string_view NullEncrypter::GetKey() const { return absl::string_view(); } |
| |
| absl::string_view NullEncrypter::GetNoncePrefix() const { |
| return absl::string_view(); |
| } |
| |
| size_t NullEncrypter::GetHashLength() const { return kHashSizeShort; } |
| |
| } // namespace quic |