tls: improve wildcard matching (#11921) (#11927)

Patching in 11885 with runtime guards and release notes Risk Level: Medium (changes to cert matching) Testing: new unit test Docs Changes: n/a Release Notes: inline Runtime guard: envoy.reloadable_features.fix_wildcard_matching Signed-off-by: Yann Soubeyrand <yann.soubeyrand@camptocamp.com> Signed-off-by: Alyssa Wilk <alyssar@chromium.org> Signed-off-by: Piotr Sikora <piotrsikora@google.com>
envoyproxy · Jul 7, 2020 · b2ffdd8 · b2ffdd8
1 parent a59ef68
commit b2ffdd8
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Showing 7 changed files with 53 additions and 3 deletions.
diff --git a/VERSION b/VERSION
@@ -1 +1 @@
-1.12.5
+1.12.6
diff --git a/docs/root/intro/version_history.rst b/docs/root/intro/version_history.rst
@@ -1,6 +1,10 @@
 Version history
 ---------------
 
+1.12.6 (July 7, 2020)
+=====================
+* tls: fixed a bug where wilcard matching for "\*.foo.com" also matched domains of the form "a.b.foo.com". This behavior can be temporarily reverted by setting runtime feature `envoy.reloadable_features.fix_wildcard_matching` to false.
+
 1.12.5 (June 30, 2020)
 ======================
 * buffer: fixed CVE-2020-12603 by avoiding fragmentation, and tracking of HTTP/2 data and control frames in the output buffer.

diff --git a/source/common/runtime/runtime_features.cc b/source/common/runtime/runtime_features.cc
@@ -31,6 +31,7 @@ constexpr const char* runtime_features[] = {
     "envoy.reloadable_features.outlier_detection_support_for_grpc_status",
     "envoy.reloadable_features.strict_header_validation",
     "envoy.reloadable_features.strict_authority_validation",
+    "envoy.reloadable_features.fix_wildcard_matching",
 };
 
 // This is a list of configuration fields which are disallowed by default in Envoy

diff --git a/source/extensions/transport_sockets/tls/BUILD b/source/extensions/transport_sockets/tls/BUILD
@@ -101,6 +101,7 @@ envoy_cc_library(
         "//source/common/common:utility_lib",
         "//source/common/network:address_lib",
         "//source/common/protobuf:utility_lib",
+        "//source/common/runtime:runtime_lib",
         "//source/common/stats:symbol_table_lib",
         "//source/extensions/transport_sockets/tls/private_key:private_key_manager_lib",
         "@envoy_api//envoy/admin/v2alpha:pkg_cc_proto",

diff --git a/source/extensions/transport_sockets/tls/context_impl.cc b/source/extensions/transport_sockets/tls/context_impl.cc
@@ -17,6 +17,7 @@
 #include "common/common/utility.h"
 #include "common/network/address_impl.h"
 #include "common/protobuf/utility.h"
+#include "common/runtime/runtime_impl.h"
 
 #include "extensions/transport_sockets/tls/utility.h"
 
@@ -635,8 +636,13 @@ bool ContextImpl::dnsNameMatch(const std::string& dns_name, const char* pattern)
   size_t pattern_len = strlen(pattern);
   if (pattern_len > 1 && pattern[0] == '*' && pattern[1] == '.') {
     if (dns_name.length() > pattern_len - 1) {
-      size_t off = dns_name.length() - pattern_len + 1;
-      return dns_name.compare(off, pattern_len - 1, pattern + 1) == 0;
+      const size_t off = dns_name.length() - pattern_len + 1;
+      if (Runtime::runtimeFeatureEnabled("envoy.reloadable_features.fix_wildcard_matching")) {
+        return dns_name.substr(0, off).find('.') == std::string::npos &&
+               dns_name.compare(off, pattern_len - 1, pattern + 1) == 0;
+      } else {
+        return dns_name.compare(off, pattern_len - 1, pattern + 1) == 0;
+      }
     }
   }
 

diff --git a/test/extensions/transport_sockets/tls/BUILD b/test/extensions/transport_sockets/tls/BUILD
@@ -82,6 +82,7 @@ envoy_cc_test(
         "//test/mocks/ssl:ssl_mocks",
         "//test/test_common:environment_lib",
         "//test/test_common:simulated_time_system_lib",
+        "//test/test_common:test_runtime_lib",
     ],
 )
 

diff --git a/test/extensions/transport_sockets/tls/context_impl_test.cc b/test/extensions/transport_sockets/tls/context_impl_test.cc
@@ -20,6 +20,7 @@
 #include "test/mocks/ssl/mocks.h"
 #include "test/test_common/environment.h"
 #include "test/test_common/simulated_time_system.h"
+#include "test/test_common/test_runtime.h"
 #include "test/test_common/utility.h"
 
 #include "gtest/gtest.h"
@@ -44,6 +45,23 @@ class SslContextImplTest : public SslCertsTest {
 TEST_F(SslContextImplTest, TestDnsNameMatching) {
   EXPECT_TRUE(ContextImpl::dnsNameMatch("lyft.com", "lyft.com"));
   EXPECT_TRUE(ContextImpl::dnsNameMatch("a.lyft.com", "*.lyft.com"));
+  EXPECT_FALSE(ContextImpl::dnsNameMatch("a.b.lyft.com", "*.lyft.com"));
+  EXPECT_FALSE(ContextImpl::dnsNameMatch("foo.test.com", "*.lyft.com"));
+  EXPECT_FALSE(ContextImpl::dnsNameMatch("lyft.com", "*.lyft.com"));
+  EXPECT_FALSE(ContextImpl::dnsNameMatch("alyft.com", "*.lyft.com"));
+  EXPECT_FALSE(ContextImpl::dnsNameMatch("alyft.com", "*lyft.com"));
+  EXPECT_FALSE(ContextImpl::dnsNameMatch("lyft.com", "*lyft.com"));
+  EXPECT_FALSE(ContextImpl::dnsNameMatch("", "*lyft.com"));
+  EXPECT_FALSE(ContextImpl::dnsNameMatch("lyft.com", ""));
+}
+
+TEST_F(SslContextImplTest, TestDnsNameMatchingLegacy) {
+  TestScopedRuntime scoped_runtime;
+  Runtime::LoaderSingleton::getExisting()->mergeValues(
+      {{"envoy.reloadable_features.fix_wildcard_matching", "false"}});
+  EXPECT_TRUE(ContextImpl::dnsNameMatch("lyft.com", "lyft.com"));
+  EXPECT_TRUE(ContextImpl::dnsNameMatch("a.lyft.com", "*.lyft.com"));
+  // Legacy behavior
   EXPECT_TRUE(ContextImpl::dnsNameMatch("a.b.lyft.com", "*.lyft.com"));
   EXPECT_FALSE(ContextImpl::dnsNameMatch("foo.test.com", "*.lyft.com"));
   EXPECT_FALSE(ContextImpl::dnsNameMatch("lyft.com", "*.lyft.com"));
@@ -70,6 +88,25 @@ TEST_F(SslContextImplTest, TestVerifySubjectAltNameURIMatched) {
   EXPECT_TRUE(ContextImpl::verifySubjectAltName(cert.get(), verify_subject_alt_name_list));
 }
 
+TEST_F(SslContextImplTest, TestVerifySubjectAltMultiDomain) {
+  bssl::UniquePtr<X509> cert = readCertFromFile(TestEnvironment::substitute(
+      "{{ test_rundir "
+      "}}/test/extensions/transport_sockets/tls/test_data/san_multiple_dns_cert.pem"));
+  std::vector<std::string> verify_subject_alt_name_list = {"https://a.www.example.com"};
+  EXPECT_FALSE(ContextImpl::verifySubjectAltName(cert.get(), verify_subject_alt_name_list));
+}
+
+TEST_F(SslContextImplTest, TestVerifySubjectAltMultiDomainLegacy) {
+  TestScopedRuntime scoped_runtime;
+  Runtime::LoaderSingleton::getExisting()->mergeValues(
+      {{"envoy.reloadable_features.fix_wildcard_matching", "false"}});
+  bssl::UniquePtr<X509> cert = readCertFromFile(TestEnvironment::substitute(
+      "{{ test_rundir "
+      "}}/test/extensions/transport_sockets/tls/test_data/san_multiple_dns_cert.pem"));
+  std::vector<std::string> verify_subject_alt_name_list = {"https://a.www.example.com"};
+  EXPECT_TRUE(ContextImpl::verifySubjectAltName(cert.get(), verify_subject_alt_name_list));
+}
+
 TEST_F(SslContextImplTest, TestVerifySubjectAltNameNotMatched) {
   bssl::UniquePtr<X509> cert = readCertFromFile(TestEnvironment::substitute(
       "{{ test_rundir }}/test/extensions/transport_sockets/tls/test_data/san_dns_cert.pem"));