code: /*
   * Copyright 2018-2020 The OpenSSL Project Authors. All Rights Reserved.
   *
   * Licensed under the Apache License 2.0 (the "License").  You may not use
   * this file except in compliance with the License.  You can obtain a copy
   * in the file LICENSE in the source distribution or at
   * https://www.openssl.org/source/license.html
   */
  
  #include "../testutil.h"
  #include <openssl/provider.h>
  #include <string.h>
  
  int test_get_libctx(OSSL_LIB_CTX **libctx, OSSL_PROVIDER **default_null_prov,
                      const char *config_file,
                      OSSL_PROVIDER **provider, const char *module_name)
  {
      if ((*libctx = OSSL_LIB_CTX_new()) == NULL) {
          opt_printf_stderr("Failed to create libctx\n");
          goto err;
      }
  
      if (default_null_prov != NULL
          && (*default_null_prov = OSSL_PROVIDER_load(NULL, "null")) == NULL) {
          opt_printf_stderr("Failed to load null provider into default libctx\n");
          goto err;
      }
  
      if (config_file != NULL
              && !OSSL_LIB_CTX_load_config(*libctx, config_file)) {
          opt_printf_stderr("Error loading config from file %s\n", config_file);
          goto err;
      }
  
      if (module_name != NULL
              && (*provider = OSSL_PROVIDER_load(*libctx, module_name)) == NULL) {
          opt_printf_stderr("Failed to load provider %s\n", module_name);
          goto err;
      }
      return 1;
  
   err:
      ERR_print_errors_fp(stderr);
      return 0;
  }
  
  int test_arg_libctx(OSSL_LIB_CTX **libctx, OSSL_PROVIDER **default_null_prov,
                      OSSL_PROVIDER **provider, int argn, const char *usage)
  {
      const char *module_name;
  
      if (!TEST_ptr(module_name = test_get_argument(argn))) {
          TEST_error("usage: <prog> %s", usage);
          return 0;
      }
      if (strcmp(module_name, "none") == 0)
          return 1;
      return test_get_libctx(libctx, default_null_prov,
                             test_get_argument(argn + 1), provider, module_name);
  }
  