Files
cromite/build/patches/Disable-TLS-resumption.patch
2026-05-19 10:48:25 +02:00

262 lines
11 KiB
Diff

From: uazo <uazo@users.noreply.github.com>
Date: Thu, 24 Mar 2022 10:08:00 +0000
Subject: Disable TLS resumption
Disable resumption feature for all HTTPS and QUIC connections;
the feature could be used to track users even without cookies.
Sessions are not currently saved to disk in Chromium (although
there is support for it) but are long enough to constitute a
privacy risk (2h for TLS 1.2 and 7 days for TLS 1.3) if user
does not frequently close the browser.
Since session information is not kept in the HTTP cache it is
not cleared when deleting navigation data (although it is possible
to clear it by selecting "passwords").
Two new user configurable flags are introduced:
* kDisableTLSResumption, active by default
* kLogTLSResumption, that would allow to find in logcat reused
sessions in lines matching "SSL Log:"
See also:
* https://arxiv.org/abs/1810.07304
Original License: GPL-2.0-or-later - https://spdx.org/licenses/GPL-2.0-or-later.html
License: GPL-3.0-only - https://spdx.org/licenses/GPL-3.0-only.html
---
.../about_flags_cc/Disable-TLS-resumption.inc | 12 ++++
.../features_cc/Disable-TLS-resumption.inc | 7 ++
.../features_h/Disable-TLS-resumption.inc | 5 ++
net/http/http_network_session.cc | 1 +
net/quic/quic_session_pool.cc | 35 +++++++++-
net/socket/ssl_client_socket_impl.cc | 68 +++++++++++++++++++
net/socket/ssl_client_socket_impl.h | 2 +
7 files changed, 128 insertions(+), 2 deletions(-)
create mode 100644 cromite_flags/chrome/browser/about_flags_cc/Disable-TLS-resumption.inc
create mode 100644 cromite_flags/net/base/features_cc/Disable-TLS-resumption.inc
create mode 100644 cromite_flags/net/base/features_h/Disable-TLS-resumption.inc
diff --git a/cromite_flags/chrome/browser/about_flags_cc/Disable-TLS-resumption.inc b/cromite_flags/chrome/browser/about_flags_cc/Disable-TLS-resumption.inc
new file mode 100644
--- /dev/null
+++ b/cromite_flags/chrome/browser/about_flags_cc/Disable-TLS-resumption.inc
@@ -0,0 +1,12 @@
+#ifdef FLAG_SECTION
+
+ {"disable-tls-resumption",
+ "Disable TLS Session Resumption",
+ "Disable TLS session resumption.", kOsAll,
+ FEATURE_VALUE_TYPE(net::features::kDisableTLSResumption)},
+ {"log-tls-resumption",
+ "Log TLS Session Resumption",
+ "Log TLS Session Resumption", kOsAll,
+ FEATURE_VALUE_TYPE(net::features::kLogTLSResumption)},
+
+#endif
diff --git a/cromite_flags/net/base/features_cc/Disable-TLS-resumption.inc b/cromite_flags/net/base/features_cc/Disable-TLS-resumption.inc
new file mode 100644
--- /dev/null
+++ b/cromite_flags/net/base/features_cc/Disable-TLS-resumption.inc
@@ -0,0 +1,7 @@
+CROMITE_FEATURE(kDisableTLSResumption,
+ "DisableTLSResumption",
+ base::FEATURE_ENABLED_BY_DEFAULT);
+
+CROMITE_FEATURE(kLogTLSResumption,
+ "LogTLSResumption",
+ base::FEATURE_DISABLED_BY_DEFAULT);
diff --git a/cromite_flags/net/base/features_h/Disable-TLS-resumption.inc b/cromite_flags/net/base/features_h/Disable-TLS-resumption.inc
new file mode 100644
--- /dev/null
+++ b/cromite_flags/net/base/features_h/Disable-TLS-resumption.inc
@@ -0,0 +1,5 @@
+// Disables TLS resumption.
+NET_EXPORT BASE_DECLARE_FEATURE(kDisableTLSResumption);
+
+// Log TLS resumption.
+NET_EXPORT BASE_DECLARE_FEATURE(kLogTLSResumption);
diff --git a/net/http/http_network_session.cc b/net/http/http_network_session.cc
--- a/net/http/http_network_session.cc
+++ b/net/http/http_network_session.cc
@@ -217,6 +217,7 @@ HttpNetworkSession::HttpNetworkSession(const HttpNetworkSessionParams& params,
next_protos_.push_back(NextProto::kProtoHTTP11);
+ DCHECK(context.quic_context->params()->max_server_configs_stored_in_properties == 0);
http_server_properties_->SetMaxServerConfigsStoredInProperties(
context.quic_context->params()->max_server_configs_stored_in_properties);
http_server_properties_->SetBrokenAlternativeServicesDelayParams(
diff --git a/net/quic/quic_session_pool.cc b/net/quic/quic_session_pool.cc
--- a/net/quic/quic_session_pool.cc
+++ b/net/quic/quic_session_pool.cc
@@ -384,6 +384,38 @@ base::TimeDelta GetAdditionalDelayForMainJob() {
} // namespace
+class BromiteSessionCache : public quic::QuicClientSessionCache {
+ public:
+ BromiteSessionCache() = default;
+ ~BromiteSessionCache() override = default;
+
+ void Insert(const quic::QuicServerId& server_id,
+ bssl::UniquePtr<SSL_SESSION> session,
+ const quic::TransportParameters& params,
+ const quic::ApplicationState* application_state) override {
+ if (base::FeatureList::IsEnabled(net::features::kDisableTLSResumption))
+ SSL_SESSION_set_timeout(session.get(), 0);
+ if (base::FeatureList::IsEnabled(net::features::kLogTLSResumption)) {
+ LOG(INFO) << "SSL Log: new quic session created "
+ << server_id.host();
+ }
+ quic::QuicClientSessionCache::Insert(server_id,
+ std::move(session), params, application_state);
+ }
+
+ std::unique_ptr<quic::QuicResumptionState> Lookup(
+ const quic::QuicServerId& server_id, quic::QuicWallTime now,
+ const SSL_CTX* ctx) override {
+ auto value = quic::QuicClientSessionCache::Lookup(server_id, now, ctx);
+ if (value != nullptr &&
+ base::FeatureList::IsEnabled(net::features::kLogTLSResumption)) {
+ LOG(INFO) << "SSL Log: QUIC session resumed "
+ << server_id.host();
+ }
+ return value;
+ }
+};
+
QuicSessionRequest::QuicSessionRequest(QuicSessionPool* pool) : pool_(pool) {}
QuicSessionRequest::~QuicSessionRequest() {
@@ -2484,8 +2516,7 @@ QuicSessionPool::CreateCryptoConfigHandle(QuicCryptoClientConfigKey key) {
cert_verifier_, transport_security_state_, sct_auditing_delegate_,
std::move(hostnames_to_allow_unknown_roots),
key.network_anonymization_key),
- std::make_unique<quic::QuicClientSessionCache>(
- kDefaultQuicSessionCacheSize),
+ std::make_unique<BromiteSessionCache>(),
kDefaultQuicSessionCacheSize, this);
quic::QuicCryptoClientConfig* crypto_config = crypto_config_owner->config();
diff --git a/net/socket/ssl_client_socket_impl.cc b/net/socket/ssl_client_socket_impl.cc
--- a/net/socket/ssl_client_socket_impl.cc
+++ b/net/socket/ssl_client_socket_impl.cc
@@ -31,6 +31,7 @@
#include "base/strings/string_view_util.h"
#include "base/synchronization/lock.h"
#include "base/task/sequenced_task_runner.h"
+#include "base/types/fixed_array.h"
#include "base/trace_event/trace_event.h"
#include "base/values.h"
#include "build/build_config.h"
@@ -292,7 +293,41 @@ SSLClientSocketImpl::SSLClientSocketImpl(
CHECK(context_);
}
+void SSLClientSocketImpl::Log_ssl_session_data(const std::string& tag, SSL_SESSION* session) {
+ if (session == NULL) {
+ LOG(INFO) << "SSL Log: "
+ << tag
+ << " host: " << host_and_port_.ToString()
+ << " NIK: " << ssl_config_.network_anonymization_key.ToDebugString();
+ return;
+ }
+
+ unsigned len;
+ const uint8_t *session_id = SSL_SESSION_get_id(session, &len);
+ base::FixedArray<uint8_t> session_id_bytes(len);
+ for (unsigned i = 0; i < len; i++) {
+ session_id_bytes[i] = UNSAFE_TODO(session_id[i]);
+ }
+
+ const uint8_t *ticket;
+ size_t ticklen;
+ SSL_SESSION_get0_ticket(session, &ticket, &ticklen);
+ base::FixedArray<uint8_t> ticket_bytes(ticklen);
+ for (size_t i = 0; i < ticklen; i++) {
+ ticket_bytes[i] = UNSAFE_TODO(ticket[i]);
+ }
+
+ LOG(INFO) << "SSL Log: "
+ << tag
+ << " host: " << host_and_port_.ToString()
+ << " NIK: " << ssl_config_.network_anonymization_key.ToDebugString()
+ << " sessionid: " << base::HexEncode(base::span<uint8_t>(session_id_bytes))
+ << (ticklen > 0 ? " ticket:" + base::HexEncode(ticket_bytes) : "");
+}
+
SSLClientSocketImpl::~SSLClientSocketImpl() {
+ if (base::FeatureList::IsEnabled(net::features::kLogTLSResumption))
+ Log_ssl_session_data("Disconnect", NULL);
Disconnect();
}
@@ -710,6 +745,8 @@ int SSLClientSocketImpl::Init() {
}
if (session)
SSL_set_session(ssl_.get(), session.get());
+ if (session && base::FeatureList::IsEnabled(net::features::kLogTLSResumption))
+ Log_ssl_session_data("Old session resumed", session.get());
}
transport_adapter_ = std::make_unique<SocketBIOAdapter>(
@@ -994,6 +1031,35 @@ int SSLClientSocketImpl::DoHandshakeComplete(int result) {
: SSLHandshakeDetails::kTLS13Full;
}
}
+ if (base::FeatureList::IsEnabled(net::features::kLogTLSResumption)) {
+ switch(details)
+ {
+ case SSLHandshakeDetails::kTLS13Early:
+ Log_ssl_session_data("SSL Log: session reused: kTLS13Early mode", NULL);
+ break;
+ case SSLHandshakeDetails::kTLS13ResumeWithHelloRetryRequest:
+ Log_ssl_session_data("SSL Log: session reused: kTLS13ResumeWithHelloRetryRequest mode", NULL);
+ break;
+ case SSLHandshakeDetails::kTLS13Resume:
+ Log_ssl_session_data("SSL Log: session reused: kTLS13Resume mode", NULL);
+ break;
+ case SSLHandshakeDetails::kTLS12Resume:
+ Log_ssl_session_data("SSL Log: session reused: kTLS12Resume mode", NULL);
+ break;
+ case SSLHandshakeDetails::kTLS12Full:
+ Log_ssl_session_data("SSL Log: session reused: kTLS12Full mode", NULL);
+ break;
+ case SSLHandshakeDetails::kTLS12FalseStart:
+ Log_ssl_session_data("SSL Log: session reused: kTLS12FalseStart mode", NULL);
+ break;
+ case SSLHandshakeDetails::kTLS13Full:
+ Log_ssl_session_data("SSL Log: session reused: kTLS13Full mode", NULL);
+ break;
+ case SSLHandshakeDetails::kTLS13FullWithHelloRetryRequest:
+ Log_ssl_session_data("SSL Log: session reused: kTLS13FullWithHelloRetryRequest mode", NULL);
+ break;
+ }
+ }
UMA_HISTOGRAM_ENUMERATION("Net.SSLHandshakeDetails", details);
// Measure TLS connections that implement the renegotiation_info and EMS
@@ -1624,6 +1690,8 @@ bool SSLClientSocketImpl::IsRenegotiationAllowed() const {
}
bool SSLClientSocketImpl::IsCachingEnabled() const {
+ if (base::FeatureList::IsEnabled(net::features::kDisableTLSResumption))
+ return false;
return context_->ssl_client_session_cache() != nullptr;
}
diff --git a/net/socket/ssl_client_socket_impl.h b/net/socket/ssl_client_socket_impl.h
--- a/net/socket/ssl_client_socket_impl.h
+++ b/net/socket/ssl_client_socket_impl.h
@@ -128,6 +128,8 @@ class NET_EXPORT_PRIVATE SSLClientSocketImpl
friend class SSLContext;
FRIEND_TEST_ALL_PREFIXES(SSLClientSocketTest, ParseServerTrustAnchorIDs);
+ void Log_ssl_session_data(const std::string& tag, SSL_SESSION* session);
+
int Init();
void DoReadCallback(int result);
void DoWriteCallback(int result);
--