Added support for default credentials.

- Tested with new tool (print_default_creds_token) on:
  - workstation for env var and well known place.
  - GCE for compute engine default creds.
- I'd prefer the grpc_default_credentials_create() API to remain
  synchronous even though there may be an async call for gce detection
  on which we block.

1 files changed, 107 insertions, 0 deletions

diff --git a/test/core/security/print_default_creds_token.c b/test/core/security/print_default_creds_token.c
new file mode 100644
index 0000000000..b11acace40
--- /dev/null
+++ b/test/core/security/print_default_creds_token.c
@@ -0,0 +1,107 @@
+/*
+ *
+ * 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.
+ *
+ */
+
+#include <stdio.h>
+#include <string.h>
+
+#include "src/core/security/credentials.h"
+#include <grpc/grpc.h>
+#include <grpc/grpc_security.h>
+#include <grpc/support/alloc.h>
+#include <grpc/support/cmdline.h>
+#include <grpc/support/log.h>
+#include <grpc/support/slice.h>
+#include <grpc/support/sync.h>
+
+typedef struct {
+  gpr_cv cv;
+  gpr_mu mu;
+  int is_done;
+} synchronizer;
+
+static void on_metadata_response(void *user_data, grpc_mdelem **md_elems,
+                                 size_t num_md,
+                                 grpc_credentials_status status) {
+  synchronizer *sync = user_data;
+  if (status == GRPC_CREDENTIALS_ERROR) {
+    fprintf(stderr, "Fetching token failed.\n");
+  } else {
+    GPR_ASSERT(num_md == 1);
+    printf("\nGot token: %s\n\n",
+           (const char *)GPR_SLICE_START_PTR(md_elems[0]->value->slice));
+  }
+  gpr_mu_lock(&sync->mu);
+  sync->is_done = 1;
+  gpr_mu_unlock(&sync->mu);
+  gpr_cv_signal(&sync->cv);
+}
+
+int main(int argc, char **argv) {
+  int result = 0;
+  synchronizer sync;
+  grpc_credentials *creds = NULL;
+  char *service_url = "https://test.foo.google.com/Foo";
+  gpr_cmdline *cl = gpr_cmdline_create("print_default_creds_token");
+  gpr_cmdline_add_string(cl, "service_url",
+                         "Service URL for the token request.",
+                         &service_url);
+  gpr_cmdline_parse(cl, argc, argv);
+
+  grpc_init();
+
+  creds = grpc_default_credentials_create();
+  if (creds == NULL) {
+    fprintf(stderr, "\nCould not find default credentials.\n\n");
+    result = 1;
+    goto end;
+  }
+
+  gpr_mu_init(&sync.mu);
+  gpr_cv_init(&sync.cv);
+  sync.is_done = 0;
+
+  grpc_credentials_get_request_metadata(creds, "", on_metadata_response, &sync);
+
+  gpr_mu_lock(&sync.mu);
+  while (!sync.is_done) gpr_cv_wait(&sync.cv, &sync.mu, gpr_inf_future);
+  gpr_mu_unlock(&sync.mu);
+
+  gpr_mu_destroy(&sync.mu);
+  gpr_cv_destroy(&sync.cv);
+  grpc_credentials_release(creds);
+
+end:
+  gpr_cmdline_destroy(cl);
+  grpc_shutdown();
+  return result;
+}