Refactor end2end_test. Make the credentials a separate library.
diff --git a/test/cpp/end2end/end2end_test.cc b/test/cpp/end2end/end2end_test.cc
index c852384..df9aae7 100644
--- a/test/cpp/end2end/end2end_test.cc
+++ b/test/cpp/end2end/end2end_test.cc
@@ -51,11 +51,11 @@
 #include "src/core/security/credentials.h"
 #include "src/proto/grpc/testing/duplicate/echo_duplicate.grpc.pb.h"
 #include "src/proto/grpc/testing/echo.grpc.pb.h"
-#include "test/core/end2end/data/ssl_test_data.h"
 #include "test/core/util/port.h"
 #include "test/core/util/test_config.h"
 #include "test/cpp/end2end/test_service_impl.h"
 #include "test/cpp/util/string_ref_helper.h"
+#include "test/cpp/util/test_credentials_provider.h"
 
 using grpc::testing::EchoRequest;
 using grpc::testing::EchoResponse;
@@ -191,12 +191,14 @@
 
 class TestScenario {
  public:
-  TestScenario(bool proxy, bool tls) : use_proxy(proxy), use_tls(tls) {}
+  TestScenario(bool proxy, const grpc::string& creds_type)
+      : use_proxy(proxy), credentials_type(creds_type) {}
   void Log() const {
-    gpr_log(GPR_INFO, "Scenario: proxy %d, tls %d", use_proxy, use_tls);
+    gpr_log(GPR_INFO, "Scenario: proxy %d, credentials %s", use_proxy,
+            credentials_type.c_str());
   }
   bool use_proxy;
-  bool use_tls;
+  const grpc::string credentials_type;
 };
 
 class End2endTest : public ::testing::TestWithParam<TestScenario> {
@@ -220,14 +222,8 @@
     server_address_ << "127.0.0.1:" << port;
     // Setup server
     ServerBuilder builder;
-    auto server_creds = InsecureServerCredentials();
-    if (GetParam().use_tls) {
-      SslServerCredentialsOptions::PemKeyCertPair pkcp = {test_server1_key,
-                                                          test_server1_cert};
-      SslServerCredentialsOptions ssl_opts;
-      ssl_opts.pem_root_certs = "";
-      ssl_opts.pem_key_cert_pairs.push_back(pkcp);
-      server_creds = SslServerCredentials(ssl_opts);
+    auto server_creds = GetServerCredentials(GetParam().credentials_type);
+    if (GetParam().credentials_type != kInsecureCredentialsType) {
       server_creds->SetAuthMetadataProcessor(processor);
     }
     builder.AddListeningPort(server_address_.str(), server_creds);
@@ -246,12 +242,8 @@
     }
     EXPECT_TRUE(is_server_started_);
     ChannelArguments args;
-    auto channel_creds = InsecureChannelCredentials();
-    if (GetParam().use_tls) {
-      SslCredentialsOptions ssl_opts = {test_root_cert, "", ""};
-      args.SetSslTargetNameOverride("foo.test.google.fr");
-      channel_creds = SslCredentials(ssl_opts);
-    }
+    auto channel_creds =
+        GetChannelCredentials(GetParam().credentials_type, &args);
     if (!user_agent_prefix_.empty()) {
       args.SetUserAgentPrefix(user_agent_prefix_);
     }
@@ -941,7 +933,7 @@
 
 // Takes 10s.
 TEST_P(End2endTest, ChannelStateTimeout) {
-  if (GetParam().use_tls) {
+  if (GetParam().credentials_type != kInsecureCredentialsType) {
     return;
   }
   int port = grpc_pick_unused_port_or_die();
@@ -1150,7 +1142,7 @@
  protected:
   SecureEnd2endTest() {
     GPR_ASSERT(!GetParam().use_proxy);
-    GPR_ASSERT(GetParam().use_tls);
+    GPR_ASSERT(GetParam().credentials_type != kInsecureCredentialsType);
   }
 };
 
@@ -1373,21 +1365,25 @@
   EXPECT_EQ("*.test.youtube.com", ToString(auth_ctx->GetPeerIdentity()[2]));
 }
 
-INSTANTIATE_TEST_CASE_P(End2end, End2endTest,
-                        ::testing::Values(TestScenario(false, false),
-                                          TestScenario(false, true)));
+INSTANTIATE_TEST_CASE_P(
+    End2end, End2endTest,
+    ::testing::Values(TestScenario(false, kInsecureCredentialsType),
+                      TestScenario(false, kTlsCredentialsType)));
 
-INSTANTIATE_TEST_CASE_P(End2endServerTryCancel, End2endServerTryCancelTest,
-                        ::testing::Values(TestScenario(false, false)));
+INSTANTIATE_TEST_CASE_P(
+    End2endServerTryCancel, End2endServerTryCancelTest,
+    ::testing::Values(TestScenario(false, kInsecureCredentialsType)));
 
-INSTANTIATE_TEST_CASE_P(ProxyEnd2end, ProxyEnd2endTest,
-                        ::testing::Values(TestScenario(false, false),
-                                          TestScenario(false, true),
-                                          TestScenario(true, false),
-                                          TestScenario(true, true)));
+INSTANTIATE_TEST_CASE_P(
+    ProxyEnd2end, ProxyEnd2endTest,
+    ::testing::Values(TestScenario(false, kInsecureCredentialsType),
+                      TestScenario(false, kTlsCredentialsType),
+                      TestScenario(true, kInsecureCredentialsType),
+                      TestScenario(true, kTlsCredentialsType)));
 
 INSTANTIATE_TEST_CASE_P(SecureEnd2end, SecureEnd2endTest,
-                        ::testing::Values(TestScenario(false, true)));
+                        ::testing::Values(TestScenario(false,
+                                                       kTlsCredentialsType)));
 
 }  // namespace
 }  // namespace testing
diff --git a/test/cpp/util/test_credentials_provider.cc b/test/cpp/util/test_credentials_provider.cc
new file mode 100644
index 0000000..f8380cd
--- /dev/null
+++ b/test/cpp/util/test_credentials_provider.cc
@@ -0,0 +1,74 @@
+
+/*
+ *
+ * Copyright 2016, 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.
+ *
+ */
+
+#include "test/cpp/util/test_credentials_provider.h"
+
+#include "test/core/end2end/data/ssl_test_data.h"
+
+namespace grpc {
+namespace testing {
+
+std::shared_ptr<ChannelCredentials> GetChannelCredentials(
+    const grpc::string& type, ChannelArguments* args) {
+  if (type == kInsecureCredentialsType) {
+    return InsecureChannelCredentials();
+  } else if (type == kTlsCredentialsType) {
+    SslCredentialsOptions ssl_opts = {test_root_cert, "", ""};
+    args->SetSslTargetNameOverride("foo.test.google.fr");
+    return SslCredentials(ssl_opts);
+  } else {
+    gpr_log(GPR_ERROR, "Unsupported credentials type %s.", type.c_str());
+  }
+  return nullptr;
+}
+
+std::shared_ptr<ServerCredentials> GetServerCredentials(
+    const grpc::string& type) {
+  if (type == kInsecureCredentialsType) {
+    return InsecureServerCredentials();
+  } else if (type == kTlsCredentialsType) {
+    SslServerCredentialsOptions::PemKeyCertPair pkcp = {test_server1_key,
+                                                        test_server1_cert};
+    SslServerCredentialsOptions ssl_opts;
+    ssl_opts.pem_root_certs = "";
+    ssl_opts.pem_key_cert_pairs.push_back(pkcp);
+    return SslServerCredentials(ssl_opts);
+  } else {
+    gpr_log(GPR_ERROR, "Unsupported credentials type %s.", type.c_str());
+  }
+  return nullptr;
+}
+
+}  // namespace testing
+}  // namespace grpc
diff --git a/test/cpp/util/test_credentials_provider.h b/test/cpp/util/test_credentials_provider.h
new file mode 100644
index 0000000..4f25e3b
--- /dev/null
+++ b/test/cpp/util/test_credentials_provider.h
@@ -0,0 +1,61 @@
+/*
+ *
+ * Copyright 2016, 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 GRPC_TEST_CPP_UTIL_TEST_CREDENTIALS_PROVIDER_H
+#define GRPC_TEST_CPP_UTIL_TEST_CREDENTIALS_PROVIDER_H
+
+#include <memory>
+
+#include <grpc++/security/credentials.h>
+#include <grpc++/security/server_credentials.h>
+#include <grpc++/support/channel_arguments.h>
+
+namespace grpc {
+namespace testing {
+
+const char kInsecureCredentialsType[] = "INSECURE_CREDENTIALS";
+const char kTlsCredentialsType[] = "TLS_CREDENTIALS";
+
+// Provide channel credentials according to the given type. Alter the channel
+// arguments if needed.
+std::shared_ptr<ChannelCredentials> GetChannelCredentials(
+    const grpc::string& type, ChannelArguments* args);
+
+// Provide server credentials according to the given type.
+std::shared_ptr<ServerCredentials> GetServerCredentials(
+    const grpc::string& type);
+
+}  // namespace testing
+}  // namespace grpc
+
+#endif  // GRPC_TEST_CPP_UTIL_TEST_CREDENTIALS_PROVIDER_H