diff options
Diffstat (limited to 'security/nss/gtests/ssl_gtest/ssl_recordsize_unittest.cc')
| -rw-r--r-- | security/nss/gtests/ssl_gtest/ssl_recordsize_unittest.cc | 431 |
1 files changed, 431 insertions, 0 deletions
diff --git a/security/nss/gtests/ssl_gtest/ssl_recordsize_unittest.cc b/security/nss/gtests/ssl_gtest/ssl_recordsize_unittest.cc new file mode 100644 index 000000000..00651aec5 --- /dev/null +++ b/security/nss/gtests/ssl_gtest/ssl_recordsize_unittest.cc @@ -0,0 +1,431 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim: set ts=2 et sw=2 tw=80: */ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this file, + * You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#include "secerr.h" +#include "ssl.h" +#include "sslerr.h" +#include "sslproto.h" + +#include "gtest_utils.h" +#include "scoped_ptrs.h" +#include "tls_connect.h" +#include "tls_filter.h" +#include "tls_parser.h" + +namespace nss_test { + +// This class tracks the maximum size of record that was sent, both cleartext +// and plain. It only tracks records that have an outer type of +// application_data. In TLS 1.3, this includes handshake messages. +class TlsRecordMaximum : public TlsRecordFilter { + public: + TlsRecordMaximum(const std::shared_ptr<TlsAgent>& a) + : TlsRecordFilter(a), max_ciphertext_(0), max_plaintext_(0) {} + + size_t max_ciphertext() const { return max_ciphertext_; } + size_t max_plaintext() const { return max_plaintext_; } + + protected: + PacketFilter::Action FilterRecord(const TlsRecordHeader& header, + const DataBuffer& record, size_t* offset, + DataBuffer* output) override { + std::cerr << "max: " << record << std::endl; + // Ignore unprotected packets. + if (header.content_type() != kTlsApplicationDataType) { + return KEEP; + } + + max_ciphertext_ = (std::max)(max_ciphertext_, record.len()); + return TlsRecordFilter::FilterRecord(header, record, offset, output); + } + + PacketFilter::Action FilterRecord(const TlsRecordHeader& header, + const DataBuffer& data, + DataBuffer* changed) override { + max_plaintext_ = (std::max)(max_plaintext_, data.len()); + return KEEP; + } + + private: + size_t max_ciphertext_; + size_t max_plaintext_; +}; + +void CheckRecordSizes(const std::shared_ptr<TlsAgent>& agent, + const std::shared_ptr<TlsRecordMaximum>& record_max, + size_t config) { + uint16_t cipher_suite; + ASSERT_TRUE(agent->cipher_suite(&cipher_suite)); + + size_t expansion; + size_t iv; + switch (cipher_suite) { + case TLS_AES_128_GCM_SHA256: + case TLS_AES_256_GCM_SHA384: + case TLS_CHACHA20_POLY1305_SHA256: + expansion = 16; + iv = 0; + break; + + case TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256: + expansion = 16; + iv = 8; + break; + + case TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA: + // Expansion is 20 for the MAC. Maximum block padding is 16. Maximum + // padding is added when the input plus the MAC is an exact multiple of + // the block size. + expansion = 20 + 16 - ((config + 20) % 16); + iv = 16; + break; + + default: + ADD_FAILURE() << "No expansion set for ciphersuite " + << agent->cipher_suite_name(); + return; + } + + switch (agent->version()) { + case SSL_LIBRARY_VERSION_TLS_1_3: + EXPECT_EQ(0U, iv) << "No IV for TLS 1.3"; + // We only have decryption in TLS 1.3. + EXPECT_EQ(config - 1, record_max->max_plaintext()) + << "bad plaintext length for " << agent->role_str(); + break; + + case SSL_LIBRARY_VERSION_TLS_1_2: + case SSL_LIBRARY_VERSION_TLS_1_1: + expansion += iv; + break; + + case SSL_LIBRARY_VERSION_TLS_1_0: + break; + + default: + ADD_FAILURE() << "Unexpected version " << agent->version(); + return; + } + + EXPECT_EQ(config + expansion, record_max->max_ciphertext()) + << "bad ciphertext length for " << agent->role_str(); +} + +TEST_P(TlsConnectGeneric, RecordSizeMaximum) { + uint16_t max_record_size = + (version_ >= SSL_LIBRARY_VERSION_TLS_1_3) ? 16385 : 16384; + size_t send_size = (version_ >= SSL_LIBRARY_VERSION_TLS_1_3) + ? max_record_size + : max_record_size + 1; + + EnsureTlsSetup(); + auto client_max = MakeTlsFilter<TlsRecordMaximum>(client_); + client_max->EnableDecryption(); + auto server_max = MakeTlsFilter<TlsRecordMaximum>(server_); + server_max->EnableDecryption(); + + Connect(); + client_->SendData(send_size, send_size); + server_->SendData(send_size, send_size); + server_->ReadBytes(send_size); + client_->ReadBytes(send_size); + + CheckRecordSizes(client_, client_max, max_record_size); + CheckRecordSizes(server_, server_max, max_record_size); +} + +TEST_P(TlsConnectGeneric, RecordSizeMinimumClient) { + EnsureTlsSetup(); + auto server_max = MakeTlsFilter<TlsRecordMaximum>(server_); + server_max->EnableDecryption(); + + client_->SetOption(SSL_RECORD_SIZE_LIMIT, 64); + Connect(); + SendReceive(127); // Big enough for one record, allowing for 1+N splitting. + + CheckRecordSizes(server_, server_max, 64); +} + +TEST_P(TlsConnectGeneric, RecordSizeMinimumServer) { + EnsureTlsSetup(); + auto client_max = MakeTlsFilter<TlsRecordMaximum>(client_); + client_max->EnableDecryption(); + + server_->SetOption(SSL_RECORD_SIZE_LIMIT, 64); + Connect(); + SendReceive(127); + + CheckRecordSizes(client_, client_max, 64); +} + +TEST_P(TlsConnectGeneric, RecordSizeAsymmetric) { + EnsureTlsSetup(); + auto client_max = MakeTlsFilter<TlsRecordMaximum>(client_); + client_max->EnableDecryption(); + auto server_max = MakeTlsFilter<TlsRecordMaximum>(server_); + server_max->EnableDecryption(); + + client_->SetOption(SSL_RECORD_SIZE_LIMIT, 64); + server_->SetOption(SSL_RECORD_SIZE_LIMIT, 100); + Connect(); + SendReceive(127); + + CheckRecordSizes(client_, client_max, 100); + CheckRecordSizes(server_, server_max, 64); +} + +// This just modifies the encrypted payload so to include a few extra zeros. +class TlsRecordExpander : public TlsRecordFilter { + public: + TlsRecordExpander(const std::shared_ptr<TlsAgent>& a, size_t expansion) + : TlsRecordFilter(a), expansion_(expansion) {} + + protected: + virtual PacketFilter::Action FilterRecord(const TlsRecordHeader& header, + const DataBuffer& data, + DataBuffer* changed) { + if (header.content_type() != kTlsApplicationDataType) { + return KEEP; + } + changed->Allocate(data.len() + expansion_); + changed->Write(0, data.data(), data.len()); + return CHANGE; + } + + private: + size_t expansion_; +}; + +// Tweak the plaintext of server records so that they exceed the client's limit. +TEST_P(TlsConnectTls13, RecordSizePlaintextExceed) { + EnsureTlsSetup(); + auto server_expand = MakeTlsFilter<TlsRecordExpander>(server_, 1); + server_expand->EnableDecryption(); + + client_->SetOption(SSL_RECORD_SIZE_LIMIT, 64); + Connect(); + + server_->SendData(100); + + client_->ExpectReadWriteError(); + ExpectAlert(client_, kTlsAlertRecordOverflow); + client_->ReadBytes(100); + EXPECT_EQ(SSL_ERROR_RX_RECORD_TOO_LONG, client_->error_code()); + + // Consume the alert at the server. + server_->Handshake(); + server_->CheckErrorCode(SSL_ERROR_RECORD_OVERFLOW_ALERT); +} + +// Tweak the ciphertext of server records so that they greatly exceed the limit. +// This requires a much larger expansion than for plaintext to trigger the +// guard, which runs before decryption (current allowance is 304 octets). +TEST_P(TlsConnectTls13, RecordSizeCiphertextExceed) { + EnsureTlsSetup(); + + client_->SetOption(SSL_RECORD_SIZE_LIMIT, 64); + Connect(); + + auto server_expand = MakeTlsFilter<TlsRecordExpander>(server_, 320); + server_->SendData(100); + + client_->ExpectReadWriteError(); + ExpectAlert(client_, kTlsAlertRecordOverflow); + client_->ReadBytes(100); + EXPECT_EQ(SSL_ERROR_RX_RECORD_TOO_LONG, client_->error_code()); + + // Consume the alert at the server. + server_->Handshake(); + server_->CheckErrorCode(SSL_ERROR_RECORD_OVERFLOW_ALERT); +} + +// This indiscriminately adds padding to application data records. +class TlsRecordPadder : public TlsRecordFilter { + public: + TlsRecordPadder(const std::shared_ptr<TlsAgent>& a, size_t padding) + : TlsRecordFilter(a), padding_(padding) {} + + protected: + PacketFilter::Action FilterRecord(const TlsRecordHeader& header, + const DataBuffer& record, size_t* offset, + DataBuffer* output) override { + if (header.content_type() != kTlsApplicationDataType) { + return KEEP; + } + + uint8_t inner_content_type; + DataBuffer plaintext; + if (!Unprotect(header, record, &inner_content_type, &plaintext)) { + return KEEP; + } + + if (inner_content_type != kTlsApplicationDataType) { + return KEEP; + } + + DataBuffer ciphertext; + bool ok = + Protect(header, inner_content_type, plaintext, &ciphertext, padding_); + EXPECT_TRUE(ok); + if (!ok) { + return KEEP; + } + *offset = header.Write(output, *offset, ciphertext); + return CHANGE; + } + + private: + size_t padding_; +}; + +TEST_P(TlsConnectTls13, RecordSizeExceedPad) { + EnsureTlsSetup(); + auto server_max = std::make_shared<TlsRecordMaximum>(server_); + auto server_expand = std::make_shared<TlsRecordPadder>(server_, 1); + server_->SetFilter(std::make_shared<ChainedPacketFilter>( + ChainedPacketFilterInit({server_max, server_expand}))); + server_expand->EnableDecryption(); + + client_->SetOption(SSL_RECORD_SIZE_LIMIT, 64); + Connect(); + + server_->SendData(100); + + client_->ExpectReadWriteError(); + ExpectAlert(client_, kTlsAlertRecordOverflow); + client_->ReadBytes(100); + EXPECT_EQ(SSL_ERROR_RX_RECORD_TOO_LONG, client_->error_code()); + + // Consume the alert at the server. + server_->Handshake(); + server_->CheckErrorCode(SSL_ERROR_RECORD_OVERFLOW_ALERT); +} + +TEST_P(TlsConnectGeneric, RecordSizeBadValues) { + EnsureTlsSetup(); + EXPECT_EQ(SECFailure, + SSL_OptionSet(client_->ssl_fd(), SSL_RECORD_SIZE_LIMIT, 63)); + EXPECT_EQ(SECFailure, + SSL_OptionSet(client_->ssl_fd(), SSL_RECORD_SIZE_LIMIT, -1)); + EXPECT_EQ(SECFailure, + SSL_OptionSet(server_->ssl_fd(), SSL_RECORD_SIZE_LIMIT, 16386)); + Connect(); +} + +TEST_P(TlsConnectGeneric, RecordSizeGetValues) { + EnsureTlsSetup(); + int v; + EXPECT_EQ(SECSuccess, + SSL_OptionGet(client_->ssl_fd(), SSL_RECORD_SIZE_LIMIT, &v)); + EXPECT_EQ(16385, v); + client_->SetOption(SSL_RECORD_SIZE_LIMIT, 300); + EXPECT_EQ(SECSuccess, + SSL_OptionGet(client_->ssl_fd(), SSL_RECORD_SIZE_LIMIT, &v)); + EXPECT_EQ(300, v); + Connect(); +} + +// The value of the extension is capped by the maximum version of the client. +TEST_P(TlsConnectGeneric, RecordSizeCapExtensionClient) { + EnsureTlsSetup(); + client_->SetOption(SSL_RECORD_SIZE_LIMIT, 16385); + auto capture = + MakeTlsFilter<TlsExtensionCapture>(client_, ssl_record_size_limit_xtn); + capture->EnableDecryption(); + Connect(); + + uint64_t val = 0; + EXPECT_TRUE(capture->extension().Read(0, 2, &val)); + if (version_ < SSL_LIBRARY_VERSION_TLS_1_3) { + EXPECT_EQ(16384U, val) << "Extension should be capped"; + } else { + EXPECT_EQ(16385U, val); + } +} + +// The value of the extension is capped by the maximum version of the server. +TEST_P(TlsConnectGeneric, RecordSizeCapExtensionServer) { + EnsureTlsSetup(); + server_->SetOption(SSL_RECORD_SIZE_LIMIT, 16385); + auto capture = + MakeTlsFilter<TlsExtensionCapture>(server_, ssl_record_size_limit_xtn); + capture->EnableDecryption(); + Connect(); + + uint64_t val = 0; + EXPECT_TRUE(capture->extension().Read(0, 2, &val)); + if (version_ < SSL_LIBRARY_VERSION_TLS_1_3) { + EXPECT_EQ(16384U, val) << "Extension should be capped"; + } else { + EXPECT_EQ(16385U, val); + } +} + +// Damage the client extension and the handshake fails, but the server +// doesn't generate a validation error. +TEST_P(TlsConnectGenericPre13, RecordSizeClientExtensionInvalid) { + EnsureTlsSetup(); + client_->SetOption(SSL_RECORD_SIZE_LIMIT, 1000); + static const uint8_t v[] = {0xf4, 0x1f}; + MakeTlsFilter<TlsExtensionReplacer>(client_, ssl_record_size_limit_xtn, + DataBuffer(v, sizeof(v))); + ConnectExpectAlert(server_, kTlsAlertDecryptError); +} + +// Special handling for TLS 1.3, where the alert isn't read. +TEST_F(TlsConnectStreamTls13, RecordSizeClientExtensionInvalid) { + EnsureTlsSetup(); + client_->SetOption(SSL_RECORD_SIZE_LIMIT, 1000); + static const uint8_t v[] = {0xf4, 0x1f}; + MakeTlsFilter<TlsExtensionReplacer>(client_, ssl_record_size_limit_xtn, + DataBuffer(v, sizeof(v))); + client_->ExpectSendAlert(kTlsAlertBadRecordMac); + server_->ExpectSendAlert(kTlsAlertBadRecordMac); + ConnectExpectFail(); +} + +TEST_P(TlsConnectGeneric, RecordSizeServerExtensionInvalid) { + EnsureTlsSetup(); + server_->SetOption(SSL_RECORD_SIZE_LIMIT, 1000); + static const uint8_t v[] = {0xf4, 0x1f}; + auto replace = MakeTlsFilter<TlsExtensionReplacer>( + server_, ssl_record_size_limit_xtn, DataBuffer(v, sizeof(v))); + replace->EnableDecryption(); + ConnectExpectAlert(client_, kTlsAlertIllegalParameter); +} + +class RecordSizeDefaultsTest : public ::testing::Test { + public: + void SetUp() { + EXPECT_EQ(SECSuccess, + SSL_OptionGetDefault(SSL_RECORD_SIZE_LIMIT, &default_)); + } + void TearDown() { + // Make sure to restore the default value at the end. + EXPECT_EQ(SECSuccess, + SSL_OptionSetDefault(SSL_RECORD_SIZE_LIMIT, default_)); + } + + private: + PRIntn default_ = 0; +}; + +TEST_F(RecordSizeDefaultsTest, RecordSizeBadValues) { + EXPECT_EQ(SECFailure, SSL_OptionSetDefault(SSL_RECORD_SIZE_LIMIT, 63)); + EXPECT_EQ(SECFailure, SSL_OptionSetDefault(SSL_RECORD_SIZE_LIMIT, -1)); + EXPECT_EQ(SECFailure, SSL_OptionSetDefault(SSL_RECORD_SIZE_LIMIT, 16386)); +} + +TEST_F(RecordSizeDefaultsTest, RecordSizeGetValue) { + int v; + EXPECT_EQ(SECSuccess, SSL_OptionGetDefault(SSL_RECORD_SIZE_LIMIT, &v)); + EXPECT_EQ(16385, v); + EXPECT_EQ(SECSuccess, SSL_OptionSetDefault(SSL_RECORD_SIZE_LIMIT, 3000)); + EXPECT_EQ(SECSuccess, SSL_OptionGetDefault(SSL_RECORD_SIZE_LIMIT, &v)); + EXPECT_EQ(3000, v); +} + +} // namespace nss_test |