blob: ddfa96535de07b9ded55335ae5deb9b1aee5c249 [file] [log] [blame]
// Copyright (c) 2013 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/strike_register.h"
#include <set>
#include <string>
#include "base/basictypes.h"
#include "testing/gtest/include/gtest/gtest.h"
namespace {
using net::StrikeRegister;
using std::set;
using std::string;
const uint8 kOrbit[8] = { 1, 2, 3, 4, 5, 6, 7, 8 };
// StrikeRegisterTests don't look at the random bytes so this function can
// simply set the random bytes to 0.
void SetNonce(uint8 nonce[32], unsigned time, const uint8 orbit[8]) {
nonce[0] = time >> 24;
nonce[1] = time >> 16;
nonce[2] = time >> 8;
nonce[3] = time;
memcpy(nonce + 4, orbit, 8);
memset(nonce + 12, 0, 20);
}
TEST(StrikeRegisterTest, SimpleHorizon) {
// The set must reject values created on or before its own creation time.
StrikeRegister set(10 /* max size */, 1000 /* current time */,
100 /* window secs */, kOrbit,
StrikeRegister::DENY_REQUESTS_AT_STARTUP);
uint8 nonce[32];
SetNonce(nonce, 999, kOrbit);
ASSERT_FALSE(set.Insert(nonce, 1000));
SetNonce(nonce, 1000, kOrbit);
ASSERT_FALSE(set.Insert(nonce, 1000));
}
TEST(StrikeRegisterTest, NoStartupMode) {
// Check that a strike register works immediately if NO_STARTUP_PERIOD_NEEDED
// is specified.
StrikeRegister set(10 /* max size */, 0 /* current time */,
100 /* window secs */, kOrbit,
StrikeRegister::NO_STARTUP_PERIOD_NEEDED);
uint8 nonce[32];
SetNonce(nonce, 0, kOrbit);
ASSERT_TRUE(set.Insert(nonce, 0));
ASSERT_FALSE(set.Insert(nonce, 0));
}
TEST(StrikeRegisterTest, WindowFuture) {
// The set must reject values outside the window.
StrikeRegister set(10 /* max size */, 1000 /* current time */,
100 /* window secs */, kOrbit,
StrikeRegister::DENY_REQUESTS_AT_STARTUP);
uint8 nonce[32];
SetNonce(nonce, 1101, kOrbit);
ASSERT_FALSE(set.Insert(nonce, 1000));
SetNonce(nonce, 999, kOrbit);
ASSERT_FALSE(set.Insert(nonce, 1100));
}
TEST(StrikeRegisterTest, BadOrbit) {
// The set must reject values with the wrong orbit
StrikeRegister set(10 /* max size */, 1000 /* current time */,
100 /* window secs */, kOrbit,
StrikeRegister::DENY_REQUESTS_AT_STARTUP);
uint8 nonce[32];
static const uint8 kBadOrbit[8] = { 0, 0, 0, 0, 1, 1, 1, 1 };
SetNonce(nonce, 1101, kBadOrbit);
ASSERT_FALSE(set.Insert(nonce, 1100));
}
TEST(StrikeRegisterTest, OneValue) {
StrikeRegister set(10 /* max size */, 1000 /* current time */,
100 /* window secs */, kOrbit,
StrikeRegister::DENY_REQUESTS_AT_STARTUP);
uint8 nonce[32];
SetNonce(nonce, 1101, kOrbit);
ASSERT_TRUE(set.Insert(nonce, 1100));
}
TEST(StrikeRegisterTest, RejectDuplicate) {
// The set must reject values with the wrong orbit
StrikeRegister set(10 /* max size */, 1000 /* current time */,
100 /* window secs */, kOrbit,
StrikeRegister::DENY_REQUESTS_AT_STARTUP);
uint8 nonce[32];
SetNonce(nonce, 1101, kOrbit);
ASSERT_TRUE(set.Insert(nonce, 1100));
ASSERT_FALSE(set.Insert(nonce, 1100));
}
TEST(StrikeRegisterTest, HorizonUpdating) {
StrikeRegister set(5 /* max size */, 1000 /* current time */,
100 /* window secs */, kOrbit,
StrikeRegister::DENY_REQUESTS_AT_STARTUP);
uint8 nonce[6][32];
for (unsigned i = 0; i < 5; i++) {
SetNonce(nonce[i], 1101, kOrbit);
nonce[i][31] = i;
ASSERT_TRUE(set.Insert(nonce[i], 1100));
}
// This should push the oldest value out and force the horizon to be updated.
SetNonce(nonce[5], 1102, kOrbit);
ASSERT_TRUE(set.Insert(nonce[5], 1100));
// This should be behind the horizon now:
SetNonce(nonce[5], 1101, kOrbit);
nonce[5][31] = 10;
ASSERT_FALSE(set.Insert(nonce[5], 1100));
}
TEST(StrikeRegisterTest, InsertMany) {
StrikeRegister set(5000 /* max size */, 1000 /* current time */,
500 /* window secs */, kOrbit,
StrikeRegister::DENY_REQUESTS_AT_STARTUP);
uint8 nonce[32];
SetNonce(nonce, 1101, kOrbit);
for (unsigned i = 0; i < 100000; i++) {
SetNonce(nonce, 1101 + i/500, kOrbit);
memcpy(nonce + 12, &i, sizeof(i));
set.Insert(nonce, 1100);
}
}
// For the following test we create a slow, but simple, version of a
// StrikeRegister. The behaviour of this object is much easier to understand
// than the fully fledged version. We then create a test to show, empirically,
// that the two objects have identical behaviour.
// A SlowStrikeRegister has the same public interface as a StrikeRegister, but
// is much slower. Hopefully it is also more obviously correct and we can
// empirically test that their behaviours are identical.
class SlowStrikeRegister {
public:
SlowStrikeRegister(unsigned max_entries, uint32 current_time,
uint32 window_secs, const uint8 orbit[8])
: max_entries_(max_entries),
window_secs_(window_secs),
creation_time_(current_time),
horizon_(ExternalTimeToInternal(current_time + window_secs)) {
memcpy(orbit_, orbit, sizeof(orbit_));
}
bool Insert(const uint8 nonce_bytes[32], const uint32 current_time_external) {
const uint32 current_time = ExternalTimeToInternal(current_time_external);
// Check to see if the orbit is correct.
if (memcmp(nonce_bytes + 4, orbit_, sizeof(orbit_))) {
return false;
}
const uint32 nonce_time =
ExternalTimeToInternal(TimeFromBytes(nonce_bytes));
// We have dropped one or more nonces with a time value of |horizon_|, so
// we have to reject anything with a timestamp less than or equal to that.
if (nonce_time <= horizon_) {
return false;
}
// Check that the timestamp is in the current window.
if ((current_time > window_secs_ &&
nonce_time < (current_time - window_secs_)) ||
nonce_time > (current_time + window_secs_)) {
return false;
}
string nonce;
nonce.reserve(32);
nonce +=
string(reinterpret_cast<const char*>(&nonce_time), sizeof(nonce_time));
nonce +=
string(reinterpret_cast<const char*>(nonce_bytes) + sizeof(nonce_time),
32 - sizeof(nonce_time));
set<string>::const_iterator it = nonces_.find(nonce);
if (it != nonces_.end()) {
return false;
}
if (nonces_.size() == max_entries_) {
DropOldestEntry();
}
nonces_.insert(nonce);
return true;
}
private:
// TimeFromBytes returns a big-endian uint32 from |d|.
static uint32 TimeFromBytes(const uint8 d[4]) {
return static_cast<uint32>(d[0]) << 24 |
static_cast<uint32>(d[1]) << 16 |
static_cast<uint32>(d[2]) << 8 |
static_cast<uint32>(d[3]);
}
uint32 ExternalTimeToInternal(uint32 external_time) {
static const uint32 kCreationTimeFromInternalEpoch = 63115200.0;
uint32 internal_epoch = 0;
if (creation_time_ > kCreationTimeFromInternalEpoch) {
internal_epoch = creation_time_ - kCreationTimeFromInternalEpoch;
}
return external_time - internal_epoch;
}
void DropOldestEntry() {
set<string>::iterator oldest = nonces_.begin(), it;
uint32 oldest_time =
TimeFromBytes(reinterpret_cast<const uint8*>(oldest->data()));
for (it = oldest; it != nonces_.end(); it++) {
uint32 t = TimeFromBytes(reinterpret_cast<const uint8*>(it->data()));
if (t < oldest_time ||
(t == oldest_time && memcmp(it->data(), oldest->data(), 32) < 0)) {
oldest_time = t;
oldest = it;
}
}
nonces_.erase(oldest);
horizon_ = oldest_time;
}
const unsigned max_entries_;
const unsigned window_secs_;
const uint32 creation_time_;
uint8 orbit_[8];
uint32 horizon_;
set<string> nonces_;
};
TEST(StrikeRegisterStressTest, Stress) {
// Fixed seed gives reproducibility for this test.
srand(42);
unsigned max_entries = 64;
uint32 current_time = 10000, window = 200;
scoped_ptr<StrikeRegister> s1(
new StrikeRegister(max_entries, current_time, window, kOrbit,
StrikeRegister::DENY_REQUESTS_AT_STARTUP));
scoped_ptr<SlowStrikeRegister> s2(
new SlowStrikeRegister(max_entries, current_time, window, kOrbit));
uint64 i;
// When making changes it's worth removing the limit on this test and running
// it for a while. For the initial development an opt binary was left running
// for 10 minutes.
const uint64 kMaxIterations = 10000;
for (i = 0; i < kMaxIterations; i++) {
if (rand() % 1000 == 0) {
// 0.1% chance of resetting the sets.
max_entries = rand() % 300 + 2;
current_time = rand() % 10000;
window = rand() % 500;
s1.reset(new StrikeRegister(max_entries, current_time, window, kOrbit,
StrikeRegister::DENY_REQUESTS_AT_STARTUP));
s2.reset(
new SlowStrikeRegister(max_entries, current_time, window, kOrbit));
}
int32 time_delta = rand() % (window * 4);
time_delta -= window * 2;
const uint32 time = current_time + time_delta;
if (time_delta < 0 && time > current_time) {
continue; // overflow
}
uint8 nonce[32];
SetNonce(nonce, time, kOrbit);
// There are 2048 possible nonce values:
const uint32 v = rand() % 2048;
nonce[30] = v >> 8;
nonce[31] = v;
const bool r2 = s2->Insert(nonce, time);
const bool r1 = s1->Insert(nonce, time);
if (r1 != r2) {
break;
}
if (i % 10 == 0) {
s1->Validate();
}
}
if (i != kMaxIterations) {
FAIL() << "Failed after " << i << " iterations";
}
}
} // anonymous namespace