/*
 *
 * 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 "src/core/security/credentials.h"

#include <string.h>

#include "src/core/httpcli/httpcli.h"
#include "src/core/security/json_token.h"
#include "src/core/support/env.h"
#include "src/core/support/file.h"
#include "src/core/support/string.h"

#include "test/core/util/test_config.h"

#include <grpc/support/alloc.h>
#include <grpc/support/log.h>
#include <grpc/support/string_util.h>
#include <grpc/support/time.h>

#include <openssl/rsa.h>

static const char test_google_iam_authorization_token[] = "blahblahblhahb";
static const char test_google_iam_authority_selector[] = "respectmyauthoritah";
static const char test_oauth2_bearer_token[] = "Bearer blaaslkdjfaslkdfasdsfasf";
static const char test_root_cert[] = "I am the root!";

/* This JSON key was generated with the GCE console and revoked immediately.
   The identifiers have been changed as well.
   Maximum size for a string literal is 509 chars in C89, yay!  */
static const char test_json_key_str_part1[] = "{ \"private_key\": \"-----BEGIN PRIVATE KEY-----" "\\nMIICeAIBADANBgkqhkiG9w0BAQEFAASCAmIwggJeAgEAAoGBAOEvJsnoHnyHkXcp\\n7mJE" "qg" "WGjiw71NfXByguekSKho65FxaGbsnSM9SMQAqVk7Q2rG+I0OpsT0LrWQtZ\\nyjSeg/" "rWBQvS4hle4LfijkP3J5BG+" "IXDMP8RfziNRQsenAXDNPkY4kJCvKux2xdD\\nOnVF6N7dL3nTYZg+" "uQrNsMTz9UxVAgMBAAECgYEAzbLewe1xe9vy+2GoSsfib+28\\nDZgSE6Bu/" "zuFoPrRc6qL9p2SsnV7txrunTyJkkOnPLND9ABAXybRTlcVKP/sGgza\\n/" "8HpCqFYM9V8f34SBWfD4fRFT+n/" "73cfRUtGXdXpseva2lh8RilIQfPhNZAncenU\\ngqXjDvpkypEusgXAykECQQD+";
static const char test_json_key_str_part2[] = "53XxNVnxBHsYb+AYEfklR96yVi8HywjVHP34+OQZ\\nCslxoHQM8s+" "dBnjfScLu22JqkPv04xyxmt0QAKm9+vTdAkEA4ib7YvEAn2jXzcCI\\nEkoy2L/" "XydR1GCHoacdfdAwiL2npOdnbvi4ZmdYRPY1LSTO058tQHKVXV7NLeCa3\\nAARh2QJBAMKeDA" "G" "W303SQv2cZTdbeaLKJbB5drz3eo3j7dDKjrTD9JupixFbzcGw\\n8FZi5c8idxiwC36kbAL6Hz" "A" "ZoX+ofI0CQE6KCzPJTtYNqyShgKAZdJ8hwOcvCZtf\\n6z8RJm0+" "6YBd38lfh5j8mZd7aHFf6I17j5AQY7oPEc47TjJj/" "5nZ68ECQQDvYuI3\\nLyK5fS8g0SYbmPOL9TlcHDOqwG0mrX9qpg5DC2fniXNSrrZ64GTDKdzZ" "Y" "Ap6LI9W\\nIqv4vr6y38N79TTC\\n-----END PRIVATE KEY-----\\n\", ";
static const char test_json_key_str_part3[] = "\"private_key_id\": \"e6b5137873db8d2ef81e06a47289e6434ec8a165\", " "\"client_email\": " "\"777-abaslkan11hlb6nmim3bpspl31ud@developer.gserviceaccount." "com\", \"client_id\": " "\"777-abaslkan11hlb6nmim3bpspl31ud.apps.googleusercontent." "com\", \"type\": \"service_account\" }";

/* Test refresh token. */
static const char test_refresh_token_str[] = "{ \"client_id\": \"32555999999.apps.googleusercontent.com\"," "  \"client_secret\": \"EmssLNjJy1332hD4KFsecret\"," "  \"refresh_token\": \"1/Blahblasj424jladJDSGNf-u4Sua3HDA2ngjd42\"," "  \"type\": \"authorized_user\"}";

static const char valid_oauth2_json_response[] = "{\"access_token\":\"ya29.AHES6ZRN3-HlhAPya30GnW_bHSb_\"," " \"expires_in\":3599, " " \"token_type\":\"Bearer\"}";

static const char test_user_data[] = "user data";

static const char test_scope[] = "perm1 perm2";

static const char test_signed_jwt[] = "eyJhbGciOiJSUzI1NiIsInR5cCI6IkpXVCIsImtpZCI6ImY0OTRkN2M1YWU2MGRmOTcyNmM4YW" "U0MDcyZTViYTdmZDkwODg2YzcifQ";

static const char test_service_url[] = "https://foo.com/foo.v1";
static const char other_test_service_url[] = "https://bar.com/bar.v1";

static char *
test_json_key_str (void)
{
  size_t result_len = strlen (test_json_key_str_part1) + strlen (test_json_key_str_part2) + strlen (test_json_key_str_part3);
  char *result = gpr_malloc (result_len + 1);
  char *current = result;
  strcpy (result, test_json_key_str_part1);
  current += strlen (test_json_key_str_part1);
  strcpy (current, test_json_key_str_part2);
  current += strlen (test_json_key_str_part2);
  strcpy (current, test_json_key_str_part3);
  return result;
}

typedef struct
{
  const char *key;
  const char *value;
} expected_md;

static grpc_httpcli_response
http_response (int status, const char *body)
{
  grpc_httpcli_response response;
  memset (&response, 0, sizeof (grpc_httpcli_response));
  response.status = status;
  response.body = (char *) body;
  response.body_length = strlen (body);
  return response;
}

static void
test_empty_md_store (void)
{
  grpc_credentials_md_store *store = grpc_credentials_md_store_create (0);
  GPR_ASSERT (store->num_entries == 0);
  GPR_ASSERT (store->allocated == 0);
  grpc_credentials_md_store_unref (store);
}

static void
test_ref_unref_empty_md_store (void)
{
  grpc_credentials_md_store *store = grpc_credentials_md_store_create (0);
  grpc_credentials_md_store_ref (store);
  grpc_credentials_md_store_ref (store);
  GPR_ASSERT (store->num_entries == 0);
  GPR_ASSERT (store->allocated == 0);
  grpc_credentials_md_store_unref (store);
  grpc_credentials_md_store_unref (store);
  grpc_credentials_md_store_unref (store);
}

static void
test_add_to_empty_md_store (void)
{
  grpc_credentials_md_store *store = grpc_credentials_md_store_create (0);
  const char *key_str = "hello";
  const char *value_str = "there blah blah blah blah blah blah blah";
  gpr_slice key = gpr_slice_from_copied_string (key_str);
  gpr_slice value = gpr_slice_from_copied_string (value_str);
  grpc_credentials_md_store_add (store, key, value);
  GPR_ASSERT (store->num_entries == 1);
  GPR_ASSERT (gpr_slice_cmp (key, store->entries[0].key) == 0);
  GPR_ASSERT (gpr_slice_cmp (value, store->entries[0].value) == 0);
  gpr_slice_unref (key);
  gpr_slice_unref (value);
  grpc_credentials_md_store_unref (store);
}

static void
test_add_cstrings_to_empty_md_store (void)
{
  grpc_credentials_md_store *store = grpc_credentials_md_store_create (0);
  const char *key_str = "hello";
  const char *value_str = "there blah blah blah blah blah blah blah";
  grpc_credentials_md_store_add_cstrings (store, key_str, value_str);
  GPR_ASSERT (store->num_entries == 1);
  GPR_ASSERT (gpr_slice_str_cmp (store->entries[0].key, key_str) == 0);
  GPR_ASSERT (gpr_slice_str_cmp (store->entries[0].value, value_str) == 0);
  grpc_credentials_md_store_unref (store);
}

static void
test_empty_preallocated_md_store (void)
{
  grpc_credentials_md_store *store = grpc_credentials_md_store_create (4);
  GPR_ASSERT (store->num_entries == 0);
  GPR_ASSERT (store->allocated == 4);
  GPR_ASSERT (store->entries != NULL);
  grpc_credentials_md_store_unref (store);
}

static void
test_add_abunch_to_md_store (void)
{
  grpc_credentials_md_store *store = grpc_credentials_md_store_create (4);
  size_t num_entries = 1000;
  const char *key_str = "hello";
  const char *value_str = "there blah blah blah blah blah blah blah";
  size_t i;
  for (i = 0; i < num_entries; i++)
    {
      grpc_credentials_md_store_add_cstrings (store, key_str, value_str);
    }
  for (i = 0; i < num_entries; i++)
    {
      GPR_ASSERT (gpr_slice_str_cmp (store->entries[i].key, key_str) == 0);
      GPR_ASSERT (gpr_slice_str_cmp (store->entries[i].value, value_str) == 0);
    }
  grpc_credentials_md_store_unref (store);
}

static void
test_oauth2_token_fetcher_creds_parsing_ok (void)
{
  grpc_credentials_md_store *token_md = NULL;
  gpr_timespec token_lifetime;
  grpc_httpcli_response response = http_response (200, valid_oauth2_json_response);
  GPR_ASSERT (grpc_oauth2_token_fetcher_credentials_parse_server_response (&response, &token_md, &token_lifetime) == GRPC_CREDENTIALS_OK);
  GPR_ASSERT (token_lifetime.tv_sec == 3599);
  GPR_ASSERT (token_lifetime.tv_nsec == 0);
  GPR_ASSERT (token_md->num_entries == 1);
  GPR_ASSERT (gpr_slice_str_cmp (token_md->entries[0].key, "Authorization") == 0);
  GPR_ASSERT (gpr_slice_str_cmp (token_md->entries[0].value, "Bearer ya29.AHES6ZRN3-HlhAPya30GnW_bHSb_") == 0);
  grpc_credentials_md_store_unref (token_md);
}

static void
test_oauth2_token_fetcher_creds_parsing_bad_http_status (void)
{
  grpc_credentials_md_store *token_md = NULL;
  gpr_timespec token_lifetime;
  grpc_httpcli_response response = http_response (401, valid_oauth2_json_response);
  GPR_ASSERT (grpc_oauth2_token_fetcher_credentials_parse_server_response (&response, &token_md, &token_lifetime) == GRPC_CREDENTIALS_ERROR);
}

static void
test_oauth2_token_fetcher_creds_parsing_empty_http_body (void)
{
  grpc_credentials_md_store *token_md = NULL;
  gpr_timespec token_lifetime;
  grpc_httpcli_response response = http_response (200, "");
  GPR_ASSERT (grpc_oauth2_token_fetcher_credentials_parse_server_response (&response, &token_md, &token_lifetime) == GRPC_CREDENTIALS_ERROR);
}

static void
test_oauth2_token_fetcher_creds_parsing_invalid_json (void)
{
  grpc_credentials_md_store *token_md = NULL;
  gpr_timespec token_lifetime;
  grpc_httpcli_response response = http_response (200,
						  "{\"access_token\":\"ya29.AHES6ZRN3-HlhAPya30GnW_bHSb_\"," " \"expires_in\":3599, " " \"token_type\":\"Bearer\"");
  GPR_ASSERT (grpc_oauth2_token_fetcher_credentials_parse_server_response (&response, &token_md, &token_lifetime) == GRPC_CREDENTIALS_ERROR);
}

static void
test_oauth2_token_fetcher_creds_parsing_missing_token (void)
{
  grpc_credentials_md_store *token_md = NULL;
  gpr_timespec token_lifetime;
  grpc_httpcli_response response = http_response (200,
						  "{" " \"expires_in\":3599, " " \"token_type\":\"Bearer\"}");
  GPR_ASSERT (grpc_oauth2_token_fetcher_credentials_parse_server_response (&response, &token_md, &token_lifetime) == GRPC_CREDENTIALS_ERROR);
}

static void
test_oauth2_token_fetcher_creds_parsing_missing_token_type (void)
{
  grpc_credentials_md_store *token_md = NULL;
  gpr_timespec token_lifetime;
  grpc_httpcli_response response = http_response (200,
						  "{\"access_token\":\"ya29.AHES6ZRN3-HlhAPya30GnW_bHSb_\"," " \"expires_in\":3599, " "}");
  GPR_ASSERT (grpc_oauth2_token_fetcher_credentials_parse_server_response (&response, &token_md, &token_lifetime) == GRPC_CREDENTIALS_ERROR);
}

static void
test_oauth2_token_fetcher_creds_parsing_missing_token_lifetime (void)
{
  grpc_credentials_md_store *token_md = NULL;
  gpr_timespec token_lifetime;
  grpc_httpcli_response response = http_response (200,
						  "{\"access_token\":\"ya29.AHES6ZRN3-HlhAPya30GnW_bHSb_\"," " \"token_type\":\"Bearer\"}");
  GPR_ASSERT (grpc_oauth2_token_fetcher_credentials_parse_server_response (&response, &token_md, &token_lifetime) == GRPC_CREDENTIALS_ERROR);
}

static void
check_metadata (expected_md * expected, grpc_credentials_md * md_elems, size_t num_md)
{
  size_t i;
  for (i = 0; i < num_md; i++)
    {
      size_t j;
      for (j = 0; j < num_md; j++)
	{
	  if (0 == gpr_slice_str_cmp (md_elems[j].key, expected[i].key))
	    {
	      GPR_ASSERT (gpr_slice_str_cmp (md_elems[j].value, expected[i].value) == 0);
	      break;
	    }
	}
      if (j == num_md)
	{
	  gpr_log (GPR_ERROR, "key %s not found", expected[i].key);
	  GPR_ASSERT (0);
	}
    }
}

static void
check_google_iam_metadata (void *user_data, grpc_credentials_md * md_elems, size_t num_md, grpc_credentials_status status, grpc_closure_list * closure_list)
{
  grpc_credentials *c = (grpc_credentials *) user_data;
  expected_md emd[] = { {GRPC_IAM_AUTHORIZATION_TOKEN_METADATA_KEY,
			 test_google_iam_authorization_token},
  {GRPC_IAM_AUTHORITY_SELECTOR_METADATA_KEY,
   test_google_iam_authority_selector}
  };
  GPR_ASSERT (status == GRPC_CREDENTIALS_OK);
  GPR_ASSERT (num_md == 2);
  check_metadata (emd, md_elems, num_md);
  grpc_credentials_unref (c);
}

static void
test_google_iam_creds (void)
{
  grpc_closure_list closure_list = GRPC_CLOSURE_LIST_INIT;
  grpc_credentials *creds = grpc_google_iam_credentials_create (test_google_iam_authorization_token, test_google_iam_authority_selector,
								NULL);
  GPR_ASSERT (grpc_credentials_has_request_metadata (creds));
  GPR_ASSERT (grpc_credentials_has_request_metadata_only (creds));
  grpc_credentials_get_request_metadata (creds, NULL, test_service_url, check_google_iam_metadata, creds, &closure_list);
  grpc_closure_list_run (&closure_list);
}

static void
check_access_token_metadata (void *user_data, grpc_credentials_md * md_elems, size_t num_md, grpc_credentials_status status, grpc_closure_list * closure_list)
{
  grpc_credentials *c = (grpc_credentials *) user_data;
  expected_md emd[] = { {GRPC_AUTHORIZATION_METADATA_KEY, "Bearer blah"} };
  GPR_ASSERT (status == GRPC_CREDENTIALS_OK);
  GPR_ASSERT (num_md == 1);
  check_metadata (emd, md_elems, num_md);
  grpc_credentials_unref (c);
}

static void
test_access_token_creds (void)
{
  grpc_closure_list closure_list = GRPC_CLOSURE_LIST_INIT;
  grpc_credentials *creds = grpc_access_token_credentials_create ("blah", NULL);
  GPR_ASSERT (grpc_credentials_has_request_metadata (creds));
  GPR_ASSERT (grpc_credentials_has_request_metadata_only (creds));
  GPR_ASSERT (strcmp (creds->type, GRPC_CREDENTIALS_TYPE_OAUTH2) == 0);
  grpc_credentials_get_request_metadata (creds, NULL, test_service_url, check_access_token_metadata, creds, &closure_list);
  grpc_closure_list_run (&closure_list);
}

static void
check_ssl_oauth2_composite_metadata (void *user_data, grpc_credentials_md * md_elems, size_t num_md, grpc_credentials_status status, grpc_closure_list * closure_list)
{
  grpc_credentials *c = (grpc_credentials *) user_data;
  expected_md emd[] = {
    {GRPC_AUTHORIZATION_METADATA_KEY, test_oauth2_bearer_token}
  };
  GPR_ASSERT (status == GRPC_CREDENTIALS_OK);
  GPR_ASSERT (num_md == 1);
  check_metadata (emd, md_elems, num_md);
  grpc_credentials_unref (c);
}

static void
test_ssl_oauth2_composite_creds (void)
{
  grpc_closure_list closure_list = GRPC_CLOSURE_LIST_INIT;
  grpc_credentials *ssl_creds = grpc_ssl_credentials_create (test_root_cert, NULL, NULL);
  const grpc_credentials_array *creds_array;
  grpc_credentials *oauth2_creds = grpc_md_only_test_credentials_create ("Authorization", test_oauth2_bearer_token, 0);
  grpc_credentials *composite_creds = grpc_composite_credentials_create (ssl_creds, oauth2_creds, NULL);
  grpc_credentials_unref (ssl_creds);
  grpc_credentials_unref (oauth2_creds);
  GPR_ASSERT (strcmp (composite_creds->type, GRPC_CREDENTIALS_TYPE_COMPOSITE) == 0);
  GPR_ASSERT (grpc_credentials_has_request_metadata (composite_creds));
  GPR_ASSERT (!grpc_credentials_has_request_metadata_only (composite_creds));
  creds_array = grpc_composite_credentials_get_credentials (composite_creds);
  GPR_ASSERT (creds_array->num_creds == 2);
  GPR_ASSERT (strcmp (creds_array->creds_array[0]->type, GRPC_CREDENTIALS_TYPE_SSL) == 0);
  GPR_ASSERT (strcmp (creds_array->creds_array[1]->type, GRPC_CREDENTIALS_TYPE_OAUTH2) == 0);
  grpc_credentials_get_request_metadata (composite_creds, NULL, test_service_url, check_ssl_oauth2_composite_metadata, composite_creds, &closure_list);
  grpc_closure_list_run (&closure_list);
}

void
test_ssl_fake_transport_security_composite_creds_failure (void)
{
  grpc_credentials *ssl_creds = grpc_ssl_credentials_create (NULL, NULL, NULL);
  grpc_credentials *fake_transport_security_creds = grpc_fake_transport_security_credentials_create ();

  /* 2 connector credentials: should not work. */
  GPR_ASSERT (grpc_composite_credentials_create (ssl_creds, fake_transport_security_creds, NULL) == NULL);
  grpc_credentials_unref (ssl_creds);
  grpc_credentials_unref (fake_transport_security_creds);
}

static void
check_ssl_oauth2_google_iam_composite_metadata (void *user_data, grpc_credentials_md * md_elems, size_t num_md, grpc_credentials_status status, grpc_closure_list * closure_list)
{
  grpc_credentials *c = (grpc_credentials *) user_data;
  expected_md emd[] = {
    {GRPC_AUTHORIZATION_METADATA_KEY, test_oauth2_bearer_token},
    {GRPC_IAM_AUTHORIZATION_TOKEN_METADATA_KEY,
     test_google_iam_authorization_token},
    {GRPC_IAM_AUTHORITY_SELECTOR_METADATA_KEY,
     test_google_iam_authority_selector}
  };
  GPR_ASSERT (status == GRPC_CREDENTIALS_OK);
  GPR_ASSERT (num_md == 3);
  check_metadata (emd, md_elems, num_md);
  grpc_credentials_unref (c);
}

static void
test_ssl_oauth2_google_iam_composite_creds (void)
{
  grpc_closure_list closure_list = GRPC_CLOSURE_LIST_INIT;
  grpc_credentials *ssl_creds = grpc_ssl_credentials_create (test_root_cert, NULL, NULL);
  const grpc_credentials_array *creds_array;
  grpc_credentials *oauth2_creds = grpc_md_only_test_credentials_create ("Authorization", test_oauth2_bearer_token, 0);
  grpc_credentials *aux_creds = grpc_composite_credentials_create (ssl_creds, oauth2_creds, NULL);
  grpc_credentials *google_iam_creds = grpc_google_iam_credentials_create (test_google_iam_authorization_token, test_google_iam_authority_selector,
									   NULL);
  grpc_credentials *composite_creds = grpc_composite_credentials_create (aux_creds, google_iam_creds, NULL);
  grpc_credentials_unref (ssl_creds);
  grpc_credentials_unref (oauth2_creds);
  grpc_credentials_unref (aux_creds);
  grpc_credentials_unref (google_iam_creds);
  GPR_ASSERT (strcmp (composite_creds->type, GRPC_CREDENTIALS_TYPE_COMPOSITE) == 0);
  GPR_ASSERT (grpc_credentials_has_request_metadata (composite_creds));
  GPR_ASSERT (!grpc_credentials_has_request_metadata_only (composite_creds));
  creds_array = grpc_composite_credentials_get_credentials (composite_creds);
  GPR_ASSERT (creds_array->num_creds == 3);
  GPR_ASSERT (strcmp (creds_array->creds_array[0]->type, GRPC_CREDENTIALS_TYPE_SSL) == 0);
  GPR_ASSERT (strcmp (creds_array->creds_array[1]->type, GRPC_CREDENTIALS_TYPE_OAUTH2) == 0);
  GPR_ASSERT (strcmp (creds_array->creds_array[2]->type, GRPC_CREDENTIALS_TYPE_IAM) == 0);
  grpc_credentials_get_request_metadata (composite_creds, NULL, test_service_url, check_ssl_oauth2_google_iam_composite_metadata, composite_creds, &closure_list);
  grpc_closure_list_run (&closure_list);
}

static void
on_oauth2_creds_get_metadata_success (void *user_data, grpc_credentials_md * md_elems, size_t num_md, grpc_credentials_status status, grpc_closure_list * closure_list)
{
  GPR_ASSERT (status == GRPC_CREDENTIALS_OK);
  GPR_ASSERT (num_md == 1);
  GPR_ASSERT (gpr_slice_str_cmp (md_elems[0].key, "Authorization") == 0);
  GPR_ASSERT (gpr_slice_str_cmp (md_elems[0].value, "Bearer ya29.AHES6ZRN3-HlhAPya30GnW_bHSb_") == 0);
  GPR_ASSERT (user_data != NULL);
  GPR_ASSERT (strcmp ((const char *) user_data, test_user_data) == 0);
}

static void
on_oauth2_creds_get_metadata_failure (void *user_data, grpc_credentials_md * md_elems, size_t num_md, grpc_credentials_status status, grpc_closure_list * closure_list)
{
  GPR_ASSERT (status == GRPC_CREDENTIALS_ERROR);
  GPR_ASSERT (num_md == 0);
  GPR_ASSERT (user_data != NULL);
  GPR_ASSERT (strcmp ((const char *) user_data, test_user_data) == 0);
}

static void
validate_compute_engine_http_request (const grpc_httpcli_request * request)
{
  GPR_ASSERT (request->handshaker != &grpc_httpcli_ssl);
  GPR_ASSERT (strcmp (request->host, "metadata") == 0);
  GPR_ASSERT (strcmp (request->path, "/computeMetadata/v1/instance/service-accounts/default/token") == 0);
  GPR_ASSERT (request->hdr_count == 1);
  GPR_ASSERT (strcmp (request->hdrs[0].key, "Metadata-Flavor") == 0);
  GPR_ASSERT (strcmp (request->hdrs[0].value, "Google") == 0);
}

static int
compute_engine_httpcli_get_success_override (const grpc_httpcli_request * request, gpr_timespec deadline, grpc_httpcli_response_cb on_response, void *user_data, grpc_closure_list * closure_list)
{
  grpc_httpcli_response response = http_response (200, valid_oauth2_json_response);
  validate_compute_engine_http_request (request);
  on_response (user_data, &response, closure_list);
  return 1;
}

static int
compute_engine_httpcli_get_failure_override (const grpc_httpcli_request * request, gpr_timespec deadline, grpc_httpcli_response_cb on_response, void *user_data, grpc_closure_list * closure_list)
{
  grpc_httpcli_response response = http_response (403, "Not Authorized.");
  validate_compute_engine_http_request (request);
  on_response (user_data, &response, closure_list);
  return 1;
}

static int
httpcli_post_should_not_be_called (const grpc_httpcli_request * request, const char *body_bytes, size_t body_size, gpr_timespec deadline, grpc_httpcli_response_cb on_response, void *user_data, grpc_closure_list * closure_list)
{
  GPR_ASSERT ("HTTP POST should not be called" == NULL);
  return 1;
}

static int
httpcli_get_should_not_be_called (const grpc_httpcli_request * request, gpr_timespec deadline, grpc_httpcli_response_cb on_response, void *user_data, grpc_closure_list * closure_list)
{
  GPR_ASSERT ("HTTP GET should not be called" == NULL);
  return 1;
}

static void
test_compute_engine_creds_success (void)
{
  grpc_closure_list closure_list = GRPC_CLOSURE_LIST_INIT;
  grpc_credentials *compute_engine_creds = grpc_google_compute_engine_credentials_create (NULL);
  GPR_ASSERT (grpc_credentials_has_request_metadata (compute_engine_creds));
  GPR_ASSERT (grpc_credentials_has_request_metadata_only (compute_engine_creds));

  /* First request: http get should be called. */
  grpc_httpcli_set_override (compute_engine_httpcli_get_success_override, httpcli_post_should_not_be_called);
  grpc_credentials_get_request_metadata (compute_engine_creds, NULL, test_service_url, on_oauth2_creds_get_metadata_success, (void *) test_user_data, &closure_list);
  grpc_closure_list_run (&closure_list);

  /* Second request: the cached token should be served directly. */
  grpc_httpcli_set_override (httpcli_get_should_not_be_called, httpcli_post_should_not_be_called);
  grpc_credentials_get_request_metadata (compute_engine_creds, NULL, test_service_url, on_oauth2_creds_get_metadata_success, (void *) test_user_data, &closure_list);
  grpc_closure_list_run (&closure_list);

  grpc_credentials_unref (compute_engine_creds);
  grpc_httpcli_set_override (NULL, NULL);
}

static void
test_compute_engine_creds_failure (void)
{
  grpc_closure_list closure_list = GRPC_CLOSURE_LIST_INIT;
  grpc_credentials *compute_engine_creds = grpc_google_compute_engine_credentials_create (NULL);
  grpc_httpcli_set_override (compute_engine_httpcli_get_failure_override, httpcli_post_should_not_be_called);
  GPR_ASSERT (grpc_credentials_has_request_metadata (compute_engine_creds));
  GPR_ASSERT (grpc_credentials_has_request_metadata_only (compute_engine_creds));
  grpc_credentials_get_request_metadata (compute_engine_creds, NULL, test_service_url, on_oauth2_creds_get_metadata_failure, (void *) test_user_data, &closure_list);
  grpc_credentials_unref (compute_engine_creds);
  grpc_httpcli_set_override (NULL, NULL);
  grpc_closure_list_run (&closure_list);
}

static void
validate_refresh_token_http_request (const grpc_httpcli_request * request, const char *body, size_t body_size)
{
  /* The content of the assertion is tested extensively in json_token_test. */
  char *expected_body = NULL;
  GPR_ASSERT (body != NULL);
  GPR_ASSERT (body_size != 0);
  gpr_asprintf (&expected_body, GRPC_REFRESH_TOKEN_POST_BODY_FORMAT_STRING, "32555999999.apps.googleusercontent.com", "EmssLNjJy1332hD4KFsecret", "1/Blahblasj424jladJDSGNf-u4Sua3HDA2ngjd42");
  GPR_ASSERT (strlen (expected_body) == body_size);
  GPR_ASSERT (memcmp (expected_body, body, body_size) == 0);
  gpr_free (expected_body);
  GPR_ASSERT (request->handshaker == &grpc_httpcli_ssl);
  GPR_ASSERT (strcmp (request->host, GRPC_GOOGLE_OAUTH2_SERVICE_HOST) == 0);
  GPR_ASSERT (strcmp (request->path, GRPC_GOOGLE_OAUTH2_SERVICE_TOKEN_PATH) == 0);
  GPR_ASSERT (request->hdr_count == 1);
  GPR_ASSERT (strcmp (request->hdrs[0].key, "Content-Type") == 0);
  GPR_ASSERT (strcmp (request->hdrs[0].value, "application/x-www-form-urlencoded") == 0);
}

static int
refresh_token_httpcli_post_success (const grpc_httpcli_request * request, const char *body, size_t body_size, gpr_timespec deadline, grpc_httpcli_response_cb on_response, void *user_data, grpc_closure_list * closure_list)
{
  grpc_httpcli_response response = http_response (200, valid_oauth2_json_response);
  validate_refresh_token_http_request (request, body, body_size);
  on_response (user_data, &response, closure_list);
  return 1;
}

static int
refresh_token_httpcli_post_failure (const grpc_httpcli_request * request, const char *body, size_t body_size, gpr_timespec deadline, grpc_httpcli_response_cb on_response, void *user_data, grpc_closure_list * closure_list)
{
  grpc_httpcli_response response = http_response (403, "Not Authorized.");
  validate_refresh_token_http_request (request, body, body_size);
  on_response (user_data, &response, closure_list);
  return 1;
}

static void
test_refresh_token_creds_success (void)
{
  grpc_closure_list closure_list = GRPC_CLOSURE_LIST_INIT;
  grpc_credentials *refresh_token_creds = grpc_google_refresh_token_credentials_create (test_refresh_token_str,
											NULL);
  GPR_ASSERT (grpc_credentials_has_request_metadata (refresh_token_creds));
  GPR_ASSERT (grpc_credentials_has_request_metadata_only (refresh_token_creds));

  /* First request: http get should be called. */
  grpc_httpcli_set_override (httpcli_get_should_not_be_called, refresh_token_httpcli_post_success);
  grpc_credentials_get_request_metadata (refresh_token_creds, NULL, test_service_url, on_oauth2_creds_get_metadata_success, (void *) test_user_data, &closure_list);
  grpc_closure_list_run (&closure_list);

  /* Second request: the cached token should be served directly. */
  grpc_httpcli_set_override (httpcli_get_should_not_be_called, httpcli_post_should_not_be_called);
  grpc_credentials_get_request_metadata (refresh_token_creds, NULL, test_service_url, on_oauth2_creds_get_metadata_success, (void *) test_user_data, &closure_list);
  grpc_closure_list_run (&closure_list);

  grpc_credentials_unref (refresh_token_creds);
  grpc_httpcli_set_override (NULL, NULL);
  grpc_closure_list_run (&closure_list);
}

static void
test_refresh_token_creds_failure (void)
{
  grpc_closure_list closure_list = GRPC_CLOSURE_LIST_INIT;
  grpc_credentials *refresh_token_creds = grpc_google_refresh_token_credentials_create (test_refresh_token_str,
											NULL);
  grpc_httpcli_set_override (httpcli_get_should_not_be_called, refresh_token_httpcli_post_failure);
  GPR_ASSERT (grpc_credentials_has_request_metadata (refresh_token_creds));
  GPR_ASSERT (grpc_credentials_has_request_metadata_only (refresh_token_creds));
  grpc_credentials_get_request_metadata (refresh_token_creds, NULL, test_service_url, on_oauth2_creds_get_metadata_failure, (void *) test_user_data, &closure_list);
  grpc_credentials_unref (refresh_token_creds);
  grpc_httpcli_set_override (NULL, NULL);
  grpc_closure_list_run (&closure_list);
}

static void
validate_jwt_encode_and_sign_params (const grpc_auth_json_key * json_key, const char *scope, gpr_timespec token_lifetime)
{
  GPR_ASSERT (grpc_auth_json_key_is_valid (json_key));
  GPR_ASSERT (json_key->private_key != NULL);
  GPR_ASSERT (RSA_check_key (json_key->private_key));
  GPR_ASSERT (json_key->type != NULL && strcmp (json_key->type, "service_account") == 0);
  GPR_ASSERT (json_key->private_key_id != NULL && strcmp (json_key->private_key_id, "e6b5137873db8d2ef81e06a47289e6434ec8a165") == 0);
  GPR_ASSERT (json_key->client_id != NULL && strcmp (json_key->client_id, "777-abaslkan11hlb6nmim3bpspl31ud.apps." "googleusercontent.com") == 0);
  GPR_ASSERT (json_key->client_email != NULL && strcmp (json_key->client_email, "777-abaslkan11hlb6nmim3bpspl31ud@developer." "gserviceaccount.com") == 0);
  if (scope != NULL)
    GPR_ASSERT (strcmp (scope, test_scope) == 0);
  GPR_ASSERT (!gpr_time_cmp (token_lifetime, grpc_max_auth_token_lifetime));
}

static char *
encode_and_sign_jwt_success (const grpc_auth_json_key * json_key, const char *audience, gpr_timespec token_lifetime, const char *scope)
{
  validate_jwt_encode_and_sign_params (json_key, scope, token_lifetime);
  return gpr_strdup (test_signed_jwt);
}

static char *
encode_and_sign_jwt_failure (const grpc_auth_json_key * json_key, const char *audience, gpr_timespec token_lifetime, const char *scope)
{
  validate_jwt_encode_and_sign_params (json_key, scope, token_lifetime);
  return NULL;
}

static char *
encode_and_sign_jwt_should_not_be_called (const grpc_auth_json_key * json_key, const char *audience, gpr_timespec token_lifetime, const char *scope)
{
  GPR_ASSERT ("grpc_jwt_encode_and_sign should not be called" == NULL);
}

static void
on_jwt_creds_get_metadata_success (void *user_data, grpc_credentials_md * md_elems, size_t num_md, grpc_credentials_status status, grpc_closure_list * closure_list)
{
  char *expected_md_value;
  gpr_asprintf (&expected_md_value, "Bearer %s", test_signed_jwt);
  GPR_ASSERT (status == GRPC_CREDENTIALS_OK);
  GPR_ASSERT (num_md == 1);
  GPR_ASSERT (gpr_slice_str_cmp (md_elems[0].key, "Authorization") == 0);
  GPR_ASSERT (gpr_slice_str_cmp (md_elems[0].value, expected_md_value) == 0);
  GPR_ASSERT (user_data != NULL);
  GPR_ASSERT (strcmp ((const char *) user_data, test_user_data) == 0);
  gpr_free (expected_md_value);
}

static void
on_jwt_creds_get_metadata_failure (void *user_data, grpc_credentials_md * md_elems, size_t num_md, grpc_credentials_status status, grpc_closure_list * closure_list)
{
  GPR_ASSERT (status == GRPC_CREDENTIALS_ERROR);
  GPR_ASSERT (num_md == 0);
  GPR_ASSERT (user_data != NULL);
  GPR_ASSERT (strcmp ((const char *) user_data, test_user_data) == 0);
}

static void
test_jwt_creds_success (void)
{
  char *json_key_string = test_json_key_str ();
  grpc_closure_list closure_list = GRPC_CLOSURE_LIST_INIT;
  grpc_credentials *jwt_creds = grpc_service_account_jwt_access_credentials_create (json_key_string, grpc_max_auth_token_lifetime, NULL);
  GPR_ASSERT (grpc_credentials_has_request_metadata (jwt_creds));
  GPR_ASSERT (grpc_credentials_has_request_metadata_only (jwt_creds));

  /* First request: jwt_encode_and_sign should be called. */
  grpc_jwt_encode_and_sign_set_override (encode_and_sign_jwt_success);
  grpc_credentials_get_request_metadata (jwt_creds, NULL, test_service_url, on_jwt_creds_get_metadata_success, (void *) test_user_data, &closure_list);
  grpc_closure_list_run (&closure_list);

  /* Second request: the cached token should be served directly. */
  grpc_jwt_encode_and_sign_set_override (encode_and_sign_jwt_should_not_be_called);
  grpc_credentials_get_request_metadata (jwt_creds, NULL, test_service_url, on_jwt_creds_get_metadata_success, (void *) test_user_data, &closure_list);
  grpc_closure_list_run (&closure_list);

  /* Third request: Different service url so jwt_encode_and_sign should be
     called again (no caching). */
  grpc_jwt_encode_and_sign_set_override (encode_and_sign_jwt_success);
  grpc_credentials_get_request_metadata (jwt_creds, NULL, other_test_service_url, on_jwt_creds_get_metadata_success, (void *) test_user_data, &closure_list);
  grpc_closure_list_run (&closure_list);

  gpr_free (json_key_string);
  grpc_credentials_unref (jwt_creds);
  grpc_jwt_encode_and_sign_set_override (NULL);
}

static void
test_jwt_creds_signing_failure (void)
{
  char *json_key_string = test_json_key_str ();
  grpc_closure_list closure_list = GRPC_CLOSURE_LIST_INIT;
  grpc_credentials *jwt_creds = grpc_service_account_jwt_access_credentials_create (json_key_string, grpc_max_auth_token_lifetime, NULL);
  GPR_ASSERT (grpc_credentials_has_request_metadata (jwt_creds));
  GPR_ASSERT (grpc_credentials_has_request_metadata_only (jwt_creds));

  grpc_jwt_encode_and_sign_set_override (encode_and_sign_jwt_failure);
  grpc_credentials_get_request_metadata (jwt_creds, NULL, test_service_url, on_jwt_creds_get_metadata_failure, (void *) test_user_data, &closure_list);

  gpr_free (json_key_string);
  grpc_credentials_unref (jwt_creds);
  grpc_jwt_encode_and_sign_set_override (NULL);
  grpc_closure_list_run (&closure_list);
}

static void
set_google_default_creds_env_var_with_file_contents (const char *file_prefix, const char *contents)
{
  size_t contents_len = strlen (contents);
  char *creds_file_name;
  FILE *creds_file = gpr_tmpfile (file_prefix, &creds_file_name);
  GPR_ASSERT (creds_file_name != NULL);
  GPR_ASSERT (creds_file != NULL);
  GPR_ASSERT (fwrite (contents, 1, contents_len, creds_file) == contents_len);
  fclose (creds_file);
  gpr_setenv (GRPC_GOOGLE_CREDENTIALS_ENV_VAR, creds_file_name);
  gpr_free (creds_file_name);
}

static grpc_credentials *
composite_inner_creds (grpc_credentials * creds, const char *inner_creds_type)
{
  size_t i;
  grpc_composite_credentials *composite;
  GPR_ASSERT (strcmp (creds->type, GRPC_CREDENTIALS_TYPE_COMPOSITE) == 0);
  composite = (grpc_composite_credentials *) creds;
  for (i = 0; i < composite->inner.num_creds; i++)
    {
      grpc_credentials *c = composite->inner.creds_array[i];
      if (strcmp (c->type, inner_creds_type) == 0)
	return c;
    }
  GPR_ASSERT (0);		/* Not found. */
}

static void
test_google_default_creds_auth_key (void)
{
  grpc_service_account_jwt_access_credentials *jwt;
  grpc_credentials *creds;
  char *json_key = test_json_key_str ();
  grpc_flush_cached_google_default_credentials ();
  set_google_default_creds_env_var_with_file_contents ("json_key_google_default_creds", json_key);
  gpr_free (json_key);
  creds = grpc_google_default_credentials_create ();
  GPR_ASSERT (creds != NULL);
  jwt = (grpc_service_account_jwt_access_credentials *) composite_inner_creds (creds, GRPC_CREDENTIALS_TYPE_JWT);
  GPR_ASSERT (strcmp (jwt->key.client_id, "777-abaslkan11hlb6nmim3bpspl31ud.apps.googleusercontent.com") == 0);
  grpc_credentials_unref (creds);
  gpr_setenv (GRPC_GOOGLE_CREDENTIALS_ENV_VAR, "");	/* Reset. */
}

static void
test_google_default_creds_access_token (void)
{
  grpc_google_refresh_token_credentials *refresh;
  grpc_credentials *creds;
  grpc_flush_cached_google_default_credentials ();
  set_google_default_creds_env_var_with_file_contents ("refresh_token_google_default_creds", test_refresh_token_str);
  creds = grpc_google_default_credentials_create ();
  GPR_ASSERT (creds != NULL);
  refresh = (grpc_google_refresh_token_credentials *) composite_inner_creds (creds, GRPC_CREDENTIALS_TYPE_OAUTH2);
  GPR_ASSERT (strcmp (refresh->refresh_token.client_id, "32555999999.apps.googleusercontent.com") == 0);
  grpc_credentials_unref (creds);
  gpr_setenv (GRPC_GOOGLE_CREDENTIALS_ENV_VAR, "");	/* Reset. */
}

typedef enum
{
  PLUGIN_INITIAL_STATE,
  PLUGIN_GET_METADATA_CALLED_STATE,
  PLUGIN_DESTROY_CALLED_STATE
} plugin_state;

typedef struct
{
  const char *key;
  const char *value;
} plugin_metadata;

static const plugin_metadata plugin_md[] = { {"foo", "bar"}, {"hi", "there"} };

static void
plugin_get_metadata_success (void *state, const char *service_url, grpc_credentials_plugin_metadata_cb cb, void *user_data)
{
  size_t i;
  grpc_metadata md[GPR_ARRAY_SIZE (plugin_md)];
  plugin_state *s = (plugin_state *) state;
  GPR_ASSERT (strcmp (service_url, test_service_url) == 0);
  *s = PLUGIN_GET_METADATA_CALLED_STATE;
  for (i = 0; i < GPR_ARRAY_SIZE (plugin_md); i++)
    {
      memset (&md[i], 0, sizeof (grpc_metadata));
      md[i].key = plugin_md[i].key;
      md[i].value = plugin_md[i].value;
      md[i].value_length = strlen (plugin_md[i].value);
    }
  cb (user_data, md, GPR_ARRAY_SIZE (md), GRPC_STATUS_OK, NULL);
}

static void
plugin_get_metadata_failure (void *state, const char *service_url, grpc_credentials_plugin_metadata_cb cb, void *user_data)
{
  plugin_state *s = (plugin_state *) state;
  GPR_ASSERT (strcmp (service_url, test_service_url) == 0);
  *s = PLUGIN_GET_METADATA_CALLED_STATE;
  cb (user_data, NULL, 0, GRPC_STATUS_UNAUTHENTICATED, "Could not get metadata for plugin.");
}

static void
on_plugin_metadata_received_success (void *user_data, grpc_credentials_md * md_elems, size_t num_md, grpc_credentials_status status, grpc_closure_list * closure_list)
{
  size_t i = 0;
  GPR_ASSERT (user_data == NULL);
  GPR_ASSERT (md_elems != NULL);
  GPR_ASSERT (num_md == GPR_ARRAY_SIZE (plugin_md));
  for (i = 0; i < num_md; i++)
    {
      GPR_ASSERT (gpr_slice_str_cmp (md_elems[i].key, plugin_md[i].key) == 0);
      GPR_ASSERT (gpr_slice_str_cmp (md_elems[i].value, plugin_md[i].value) == 0);
    }
}

static void
on_plugin_metadata_received_failure (void *user_data, grpc_credentials_md * md_elems, size_t num_md, grpc_credentials_status status, grpc_closure_list * closure_list)
{
  GPR_ASSERT (user_data == NULL);
  GPR_ASSERT (md_elems == NULL);
  GPR_ASSERT (num_md == 0);
  GPR_ASSERT (status == GRPC_CREDENTIALS_ERROR);
}

static void
plugin_destroy (void *state)
{
  plugin_state *s = (plugin_state *) state;
  *s = PLUGIN_DESTROY_CALLED_STATE;
}

static void
test_metadata_plugin_success (void)
{
  grpc_credentials *creds;
  plugin_state state = PLUGIN_INITIAL_STATE;
  grpc_metadata_credentials_plugin plugin;
  grpc_closure_list closure_list = GRPC_CLOSURE_LIST_INIT;

  plugin.state = &state;
  plugin.get_metadata = plugin_get_metadata_success;
  plugin.destroy = plugin_destroy;

  creds = grpc_metadata_credentials_create_from_plugin (plugin, NULL);
  GPR_ASSERT (state == PLUGIN_INITIAL_STATE);
  grpc_credentials_get_request_metadata (creds, NULL, test_service_url, on_plugin_metadata_received_success, NULL, &closure_list);
  GPR_ASSERT (state == PLUGIN_GET_METADATA_CALLED_STATE);
  grpc_credentials_release (creds);
  GPR_ASSERT (state == PLUGIN_DESTROY_CALLED_STATE);
  grpc_closure_list_run (&closure_list);
}

static void
test_metadata_plugin_failure (void)
{
  grpc_credentials *creds;
  plugin_state state = PLUGIN_INITIAL_STATE;
  grpc_metadata_credentials_plugin plugin;
  grpc_closure_list closure_list = GRPC_CLOSURE_LIST_INIT;

  plugin.state = &state;
  plugin.get_metadata = plugin_get_metadata_failure;
  plugin.destroy = plugin_destroy;

  creds = grpc_metadata_credentials_create_from_plugin (plugin, NULL);
  GPR_ASSERT (state == PLUGIN_INITIAL_STATE);
  grpc_credentials_get_request_metadata (creds, NULL, test_service_url, on_plugin_metadata_received_failure, NULL, &closure_list);
  GPR_ASSERT (state == PLUGIN_GET_METADATA_CALLED_STATE);
  grpc_credentials_release (creds);
  GPR_ASSERT (state == PLUGIN_DESTROY_CALLED_STATE);
  grpc_closure_list_run (&closure_list);
}

int
main (int argc, char **argv)
{
  grpc_test_init (argc, argv);
  test_empty_md_store ();
  test_ref_unref_empty_md_store ();
  test_add_to_empty_md_store ();
  test_add_cstrings_to_empty_md_store ();
  test_empty_preallocated_md_store ();
  test_add_abunch_to_md_store ();
  test_oauth2_token_fetcher_creds_parsing_ok ();
  test_oauth2_token_fetcher_creds_parsing_bad_http_status ();
  test_oauth2_token_fetcher_creds_parsing_empty_http_body ();
  test_oauth2_token_fetcher_creds_parsing_invalid_json ();
  test_oauth2_token_fetcher_creds_parsing_missing_token ();
  test_oauth2_token_fetcher_creds_parsing_missing_token_type ();
  test_oauth2_token_fetcher_creds_parsing_missing_token_lifetime ();
  test_google_iam_creds ();
  test_access_token_creds ();
  test_ssl_oauth2_composite_creds ();
  test_ssl_oauth2_google_iam_composite_creds ();
  test_compute_engine_creds_success ();
  test_compute_engine_creds_failure ();
  test_refresh_token_creds_success ();
  test_refresh_token_creds_failure ();
  test_jwt_creds_success ();
  test_jwt_creds_signing_failure ();
  test_google_default_creds_auth_key ();
  test_google_default_creds_access_token ();
  test_metadata_plugin_success ();
  test_metadata_plugin_failure ();
  return 0;
}