1 files changed, 120 insertions, 0 deletions
diff --git a/test/core/security/alts_credentials_fuzzer.cc b/test/core/security/alts_credentials_fuzzer.cc
new file mode 100644
index 0000000000..bf18f0a589
--- /dev/null
+++ b/test/core/security/alts_credentials_fuzzer.cc
@@ -0,0 +1,120 @@
+/*
+ *
+ * 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 <string.h>
+
+#include <grpc/grpc.h>
+#include <grpc/grpc_security.h>
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+#include <grpc/support/string_util.h>
+#include "test/core/util/fuzzer_util.h"
+#include "test/core/util/memory_counters.h"
+
+#include "src/core/lib/gpr/env.h"
+#include "src/core/lib/security/credentials/alts/alts_credentials.h"
+#include "src/core/lib/security/credentials/alts/check_gcp_environment.h"
+#include "src/core/lib/security/credentials/alts/grpc_alts_credentials_options.h"
+
+using grpc_core::testing::grpc_fuzzer_get_next_byte;
+using grpc_core::testing::grpc_fuzzer_get_next_string;
+using grpc_core::testing::input_stream;
+
+// Logging
+bool squelch = true;
+bool leak_check = true;
+
+static void dont_log(gpr_log_func_args* args) {}
+
+// Add a random number of target service accounts to client options.
+static void read_target_service_accounts(
+    input_stream* inp, grpc_alts_credentials_options* options) {
+  size_t n = grpc_fuzzer_get_next_byte(inp);
+  for (size_t i = 0; i < n; i++) {
+    char* service_account = grpc_fuzzer_get_next_string(inp, nullptr);
+    if (service_account != nullptr) {
+      grpc_alts_credentials_client_options_add_target_service_account(
+          options, service_account);
+      gpr_free(service_account);
+    }
+  }
+  // Added to improve code coverage.
+  grpc_alts_credentials_client_options_add_target_service_account(options,
+                                                                  nullptr);
+  grpc_alts_credentials_client_options_add_target_service_account(
+      nullptr, "this is service account");
+}
+
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
+  char* grpc_trace_fuzzer = gpr_getenv("GRPC_TRACE_FUZZER");
+  if (squelch && grpc_trace_fuzzer == nullptr) {
+    gpr_set_log_function(dont_log);
+  }
+  gpr_free(grpc_trace_fuzzer);
+  struct grpc_memory_counters counters;
+  if (leak_check) {
+    grpc_memory_counters_init();
+  }
+  input_stream inp = {data, data + size};
+  grpc_init();
+  bool is_on_gcp = grpc_alts_is_running_on_gcp();
+  while (inp.cur != inp.end) {
+    bool enable_untrusted_alts = grpc_fuzzer_get_next_byte(&inp) & 0x01;
+    char* handshaker_service_url =
+        grpc_fuzzer_get_next_byte(&inp) & 0x01
+            ? grpc_fuzzer_get_next_string(&inp, nullptr)
+            : nullptr;
+    if (grpc_fuzzer_get_next_byte(&inp) & 0x01) {
+      // Test ALTS channel credentials.
+      grpc_alts_credentials_options* options =
+          grpc_alts_credentials_client_options_create();
+      read_target_service_accounts(&inp, options);
+      grpc_channel_credentials* cred = grpc_alts_credentials_create_customized(
+          options, handshaker_service_url, enable_untrusted_alts);
+      if (!enable_untrusted_alts && !is_on_gcp) {
+        GPR_ASSERT(cred == nullptr);
+      } else {
+        GPR_ASSERT(cred != nullptr);
+      }
+      grpc_channel_credentials_release(cred);
+      grpc_alts_credentials_options_destroy(options);
+    } else {
+      // Test ALTS server credentials.
+      grpc_alts_credentials_options* options =
+          grpc_alts_credentials_server_options_create();
+      grpc_server_credentials* cred =
+          grpc_alts_server_credentials_create_customized(
+              options, handshaker_service_url, enable_untrusted_alts);
+      if (!enable_untrusted_alts && !is_on_gcp) {
+        GPR_ASSERT(cred == nullptr);
+      } else {
+        GPR_ASSERT(cred != nullptr);
+      }
+      grpc_server_credentials_release(cred);
+      grpc_alts_credentials_options_destroy(options);
+    }
+    gpr_free(handshaker_service_url);
+  }
+  grpc_shutdown();
+  if (leak_check) {
+    counters = grpc_memory_counters_snapshot();
+    grpc_memory_counters_destroy();
+    GPR_ASSERT(counters.total_size_relative == 0);
+  }
+  return 0;
+}