blob: a8cb4c0f377590fb0ca2ff75821ee807332979e9 [file] [log] [blame]
// Copyright 2018 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 "quic/core/quic_connection_id.h"
#include <cstddef>
#include <cstdint>
#include <cstring>
#include <iomanip>
#include <string>
#include "absl/strings/escaping.h"
#include "third_party/boringssl/src/include/openssl/siphash.h"
#include "quic/core/crypto/quic_random.h"
#include "quic/core/quic_types.h"
#include "quic/platform/api/quic_bug_tracker.h"
#include "quic/platform/api/quic_flag_utils.h"
#include "quic/platform/api/quic_flags.h"
#include "quic/platform/api/quic_logging.h"
#include "common/quiche_endian.h"
namespace quic {
namespace {
// QuicConnectionIdHasher can be used to generate a stable connection ID hash
// function that will return the same value for two equal connection IDs for
// the duration of process lifetime. It is meant to be used as input to data
// structures that do not outlast process lifetime. A new key is generated once
// per process to prevent attackers from crafting connection IDs in such a way
// that they always land in the same hash bucket.
class QuicConnectionIdHasher {
public:
inline QuicConnectionIdHasher()
: QuicConnectionIdHasher(QuicRandom::GetInstance()) {}
explicit inline QuicConnectionIdHasher(QuicRandom* random) {
random->RandBytes(&sip_hash_key_, sizeof(sip_hash_key_));
}
inline size_t Hash(const char* input, size_t input_len) const {
return static_cast<size_t>(SIPHASH_24(
sip_hash_key_, reinterpret_cast<const uint8_t*>(input), input_len));
}
private:
uint64_t sip_hash_key_[2];
};
} // namespace
QuicConnectionId::QuicConnectionId() : QuicConnectionId(nullptr, 0) {
static_assert(offsetof(QuicConnectionId, padding_) ==
offsetof(QuicConnectionId, length_),
"bad offset");
static_assert(sizeof(QuicConnectionId) <= 16, "bad size");
}
QuicConnectionId::QuicConnectionId(const char* data, uint8_t length) {
length_ = length;
if (length_ == 0) {
return;
}
if (length_ <= sizeof(data_short_)) {
memcpy(data_short_, data, length_);
return;
}
data_long_ = reinterpret_cast<char*>(malloc(length_));
QUICHE_CHECK_NE(nullptr, data_long_);
memcpy(data_long_, data, length_);
}
QuicConnectionId::~QuicConnectionId() {
if (length_ > sizeof(data_short_)) {
free(data_long_);
data_long_ = nullptr;
}
}
QuicConnectionId::QuicConnectionId(const QuicConnectionId& other)
: QuicConnectionId(other.data(), other.length()) {}
QuicConnectionId& QuicConnectionId::operator=(const QuicConnectionId& other) {
set_length(other.length());
memcpy(mutable_data(), other.data(), length_);
return *this;
}
const char* QuicConnectionId::data() const {
if (length_ <= sizeof(data_short_)) {
return data_short_;
}
return data_long_;
}
char* QuicConnectionId::mutable_data() {
if (length_ <= sizeof(data_short_)) {
return data_short_;
}
return data_long_;
}
uint8_t QuicConnectionId::length() const {
return length_;
}
void QuicConnectionId::set_length(uint8_t length) {
char temporary_data[sizeof(data_short_)];
if (length > sizeof(data_short_)) {
if (length_ <= sizeof(data_short_)) {
// Copy data from data_short_ to data_long_.
memcpy(temporary_data, data_short_, length_);
data_long_ = reinterpret_cast<char*>(malloc(length));
QUICHE_CHECK_NE(nullptr, data_long_);
memcpy(data_long_, temporary_data, length_);
} else {
// Resize data_long_.
char* realloc_result =
reinterpret_cast<char*>(realloc(data_long_, length));
QUICHE_CHECK_NE(nullptr, realloc_result);
data_long_ = realloc_result;
}
} else if (length_ > sizeof(data_short_)) {
// Copy data from data_long_ to data_short_.
memcpy(temporary_data, data_long_, length);
free(data_long_);
data_long_ = nullptr;
memcpy(data_short_, temporary_data, length);
}
length_ = length;
}
bool QuicConnectionId::IsEmpty() const {
return length_ == 0;
}
size_t QuicConnectionId::Hash() const {
static const QuicConnectionIdHasher hasher = QuicConnectionIdHasher();
return hasher.Hash(data(), length_);
}
std::string QuicConnectionId::ToString() const {
if (IsEmpty()) {
return std::string("0");
}
return absl::BytesToHexString(absl::string_view(data(), length_));
}
std::ostream& operator<<(std::ostream& os, const QuicConnectionId& v) {
os << v.ToString();
return os;
}
bool QuicConnectionId::operator==(const QuicConnectionId& v) const {
return length_ == v.length_ && memcmp(data(), v.data(), length_) == 0;
}
bool QuicConnectionId::operator!=(const QuicConnectionId& v) const {
return !(v == *this);
}
bool QuicConnectionId::operator<(const QuicConnectionId& v) const {
if (length_ < v.length_) {
return true;
}
if (length_ > v.length_) {
return false;
}
return memcmp(data(), v.data(), length_) < 0;
}
QuicConnectionId EmptyQuicConnectionId() {
return QuicConnectionId();
}
static_assert(kQuicDefaultConnectionIdLength == sizeof(uint64_t),
"kQuicDefaultConnectionIdLength changed");
static_assert(kQuicDefaultConnectionIdLength == PACKET_8BYTE_CONNECTION_ID,
"kQuicDefaultConnectionIdLength changed");
} // namespace quic