Adding C++ auth metadata processor.

- We always do the processing asynchronously but maintain a synchronous
  API for the implementor of the processor.
- there are a lot of string copies right now. Having a StringPiece
  object in grpc++ would really help with that (as we would use it for
  C++ metadata).
- Please review the API carefully and if you're happy with it, I'll
  proceed with tests.

3 files changed, 70 insertions, 0 deletions

diff --git a/include/grpc++/auth_context.h b/include/grpc++/auth_context.h
index f8ea8ad6f4..0b5f856d3f 100644
--- a/include/grpc++/auth_context.h
+++ b/include/grpc++/auth_context.h
@@ -87,6 +87,11 @@ class AuthContext {
   // Iteration over all the properties.
   virtual AuthPropertyIterator begin() const = 0;
   virtual AuthPropertyIterator end() const = 0;
+
+  // Mutation functions: should only be used by an AuthMetadataProcessor.
+  virtual void AddProperty(const grpc::string& key,
+                           const grpc::string& value) = 0;
+  virtual bool SetPeerIdentityPropertyName(const grpc::string& name) = 0;
 };
 
 }  // namespace grpc
diff --git a/include/grpc++/auth_metadata_processor.h b/include/grpc++/auth_metadata_processor.h
new file mode 100644
index 0000000000..e077ec0c60
--- /dev/null
+++ b/include/grpc++/auth_metadata_processor.h
@@ -0,0 +1,60 @@
+/*
+ *
+ * Copyright 2015, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPCXX_AUTH_METADATA_PROCESSOR_H_
+#define GRPCXX_AUTH_METADATA_PROCESSOR_H_
+
+#include <map>
+#include <string>
+
+#include <grpc++/auth_context.h>
+
+namespace grpc {
+
+class AuthMetadataProcessor {
+ public:
+  virtual ~AuthMetadataProcessor() {}
+
+  // context is read/write: it contains the properties of the channel peer and
+  // it is the job of the Process method to augment it with properties derived
+  // from the passed-in auth_metadata.
+  virtual bool Process(
+      std::multimap<grpc::string, grpc::string>& auth_metadata,
+      AuthContext* context,
+      std::multimap<grpc::string, grpc::string>* consumed_auth_metadata) = 0;
+};
+
+}  // namespace grpc
+
+#endif  // GRPCXX_AUTH_METADATA_PROCESSOR_H_
+
diff --git a/include/grpc++/server_credentials.h b/include/grpc++/server_credentials.h
index 11acd67e8a..d540b95e21 100644
--- a/include/grpc++/server_credentials.h
+++ b/include/grpc++/server_credentials.h
@@ -38,6 +38,7 @@
 #include <vector>
 
 #include <grpc++/config.h>
+#include <grpc++/auth_metadata_processor.h>
 
 struct grpc_server;
 
@@ -54,6 +55,10 @@ class ServerCredentials {
 
   virtual int AddPortToServer(const grpc::string& addr,
                               grpc_server* server) = 0;
+
+  // Has to be called before the server is started.
+  virtual void SetAuthMetadataProcessor(
+      const std::shared_ptr<AuthMetadataProcessor>& processor) = 0;
 };
 
 // Options to create ServerCredentials with SSL