| /* |
| * |
| * 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 <grpc/support/alloc.h> |
| #include <grpc/support/log.h> |
| #include <grpc/support/sync.h> |
| |
| #include "src/core/httpcli/httpcli.h" |
| #include "src/core/support/env.h" |
| #include "src/core/support/file.h" |
| |
| /* -- Constants. -- */ |
| |
| #define GRPC_COMPUTE_ENGINE_DETECTION_HOST "metadata.google.internal" |
| #define GRPC_GOOGLE_CREDENTIALS_ENV_VAR "GOOGLE_APPLICATION_CREDENTIALS" |
| |
| /* -- Default credentials. -- */ |
| |
| static grpc_credentials *default_credentials = NULL; |
| static int compute_engine_detection_done = 0; |
| static gpr_mu g_mu; |
| static gpr_once g_once = GPR_ONCE_INIT; |
| |
| static void init_default_credentials(void) { |
| gpr_mu_init(&g_mu); |
| } |
| |
| typedef struct { |
| gpr_cv cv; |
| gpr_mu mu; |
| int is_done; |
| int success; |
| } compute_engine_detector; |
| |
| static void on_compute_engine_detection_http_response( |
| void *user_data, const grpc_httpcli_response *response) { |
| compute_engine_detector *detector = (compute_engine_detector *)user_data; |
| if (response != NULL && response->status == 200 && response->hdr_count > 0) { |
| /* Internet providers can return a generic response to all requests, so |
| it is necessary to check that metadata header is present also. */ |
| size_t i; |
| for (i = 0; i < response->hdr_count; i++) { |
| grpc_httpcli_header *header = &response->hdrs[i]; |
| if (!strcmp(header->key, "Metadata-Flavor") && |
| !strcmp(header->value, "Google")) { |
| detector->success = 1; |
| break; |
| } |
| } |
| } |
| gpr_mu_lock(&detector->mu); |
| detector->is_done = 1; |
| gpr_mu_unlock(&detector->mu); |
| gpr_cv_signal(&detector->cv); |
| } |
| |
| static int is_stack_running_on_compute_engine(void) { |
| compute_engine_detector detector; |
| grpc_httpcli_request request; |
| |
| /* The http call is local. If it takes more than one sec, it is for sure not |
| on compute engine. */ |
| gpr_timespec max_detection_delay = {1, 0}; |
| |
| gpr_mu_init(&detector.mu); |
| gpr_cv_init(&detector.cv); |
| detector.is_done = 0; |
| detector.success = 0; |
| |
| memset(&request, 0, sizeof(grpc_httpcli_request)); |
| request.host = GRPC_COMPUTE_ENGINE_DETECTION_HOST; |
| request.path = "/"; |
| |
| grpc_httpcli_get(&request, gpr_time_add(gpr_now(), max_detection_delay), |
| on_compute_engine_detection_http_response, &detector); |
| |
| /* Block until we get the response. This is not ideal but this should only be |
| called once for the lifetime of the process by the default credentials. */ |
| gpr_mu_lock(&detector.mu); |
| while (!detector.is_done) { |
| gpr_cv_wait(&detector.cv, &detector.mu, gpr_inf_future); |
| } |
| gpr_mu_unlock(&detector.mu); |
| |
| gpr_mu_destroy(&detector.mu); |
| gpr_cv_destroy(&detector.cv); |
| return detector.success; |
| } |
| |
| /* Takes ownership of creds_path if not NULL. */ |
| static grpc_credentials *create_jwt_creds_from_path(char *creds_path) { |
| grpc_credentials *result = NULL; |
| gpr_slice creds_data; |
| int file_ok = 0; |
| if (creds_path == NULL) return NULL; |
| creds_data = gpr_load_file(creds_path, &file_ok); |
| gpr_free(creds_path); |
| if (file_ok) { |
| result = grpc_jwt_credentials_create( |
| (const char *)GPR_SLICE_START_PTR(creds_data), |
| grpc_max_auth_token_lifetime); |
| gpr_slice_unref(creds_data); |
| } |
| return result; |
| } |
| |
| grpc_credentials *grpc_google_default_credentials_create(void) { |
| grpc_credentials *result = NULL; |
| int serving_cached_credentials = 0; |
| gpr_once_init(&g_once, init_default_credentials); |
| |
| gpr_mu_lock(&g_mu); |
| |
| if (default_credentials != NULL) { |
| result = default_credentials; |
| serving_cached_credentials = 1; |
| goto end; |
| } |
| |
| /* First, try the environment variable. */ |
| result = |
| create_jwt_creds_from_path(gpr_getenv(GRPC_GOOGLE_CREDENTIALS_ENV_VAR)); |
| if (result != NULL) goto end; |
| |
| /* Then the well-known file. */ |
| result = create_jwt_creds_from_path( |
| grpc_get_well_known_google_credentials_file_path()); |
| if (result != NULL) goto end; |
| |
| /* At last try to see if we're on compute engine (do the detection only once |
| since it requires a network test). */ |
| if (!compute_engine_detection_done) { |
| int need_compute_engine_creds = is_stack_running_on_compute_engine(); |
| compute_engine_detection_done = 1; |
| if (need_compute_engine_creds) { |
| result = grpc_compute_engine_credentials_create(); |
| } |
| } |
| |
| end: |
| if (!serving_cached_credentials && result != NULL) { |
| /* Blend with default ssl credentials and add a global reference so that it |
| can be cached and re-served. */ |
| result = grpc_composite_credentials_create( |
| grpc_ssl_credentials_create(NULL, NULL), result); |
| GPR_ASSERT(result != NULL); |
| default_credentials = grpc_credentials_ref(result); |
| } |
| gpr_mu_unlock(&g_mu); |
| return result; |
| } |