1 files changed, 76 insertions, 0 deletions
diff --git a/src/core/tsi/ssl/session_cache/ssl_session_openssl.cc b/src/core/tsi/ssl/session_cache/ssl_session_openssl.cc
new file mode 100644
index 0000000000..61c036c7eb
--- /dev/null
+++ b/src/core/tsi/ssl/session_cache/ssl_session_openssl.cc
@@ -0,0 +1,76 @@
+/*
+ *
+ * Copyright 2018 gRPC authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ */
+
+#include <grpc/support/port_platform.h>
+
+#include "src/core/tsi/ssl/session_cache/ssl_session.h"
+
+#include <grpc/support/log.h>
+
+#ifndef OPENSSL_IS_BORINGSSL
+
+// OpenSSL invalidates SSL_SESSION on SSL destruction making it pointless
+// to cache sessions. The workaround is to serialize (relatively expensive)
+// session into binary blob and re-create it from blob on every handshake.
+// Note that it's safe to keep serialized session outside of SSL lifetime
+// as openssl performs all necessary validation while attempting to use a
+// session and creates a new one if something is wrong (e.g. server changed
+// set of allowed codecs).
+
+namespace tsi {
+namespace {
+
+class OpenSslCachedSession : public SslCachedSession {
+ public:
+  OpenSslCachedSession(SslSessionPtr session) {
+    int size = i2d_SSL_SESSION(session.get(), nullptr);
+    GPR_ASSERT(size > 0);
+    grpc_slice slice = grpc_slice_malloc(size_t(size));
+    unsigned char* start = GRPC_SLICE_START_PTR(slice);
+    int second_size = i2d_SSL_SESSION(session.get(), &start);
+    GPR_ASSERT(size == second_size);
+    serialized_session_ = slice;
+  }
+
+  virtual ~OpenSslCachedSession() { grpc_slice_unref(serialized_session_); }
+
+  SslSessionPtr CopySession() const override {
+    const unsigned char* data = GRPC_SLICE_START_PTR(serialized_session_);
+    size_t length = GRPC_SLICE_LENGTH(serialized_session_);
+    SSL_SESSION* session = d2i_SSL_SESSION(nullptr, &data, length);
+    if (session == nullptr) {
+      return SslSessionPtr();
+    }
+    return SslSessionPtr(session);
+  }
+
+ private:
+  grpc_slice serialized_session_;
+};
+
+}  // namespace
+
+grpc_core::UniquePtr<SslCachedSession> SslCachedSession::Create(
+    SslSessionPtr session) {
+  return grpc_core::UniquePtr<SslCachedSession>(
+      grpc_core::New<OpenSslCachedSession>(std::move(session)));
+}
+
+}  // namespace tsi
+
+#endif /* OPENSSL_IS_BORINGSSL */