text: /*
   * Copyright 1995-2017 The OpenSSL Project Authors. All Rights Reserved.
   *
   * Licensed under the OpenSSL license (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 <stdio.h>
  #include <stdlib.h>
  #include <string.h>
  #include "apps.h"
  #include <openssl/bio.h>
  #include <openssl/err.h>
  #include <openssl/x509.h>
  #include <openssl/x509v3.h>
  #include <openssl/pem.h>
  
  static int cb(int ok, X509_STORE_CTX *ctx);
  static int check(X509_STORE *ctx, const char *file,
                   STACK_OF(X509) *uchain, STACK_OF(X509) *tchain,
                   STACK_OF(X509_CRL) *crls, int show_chain);
  static int v_verbose = 0, vflags = 0;
  
  typedef enum OPTION_choice {
      OPT_ERR = -1, OPT_EOF = 0, OPT_HELP,
      OPT_ENGINE, OPT_CAPATH, OPT_CAFILE, OPT_NOCAPATH, OPT_NOCAFILE,
      OPT_UNTRUSTED, OPT_TRUSTED, OPT_CRLFILE, OPT_CRL_DOWNLOAD, OPT_SHOW_CHAIN,
      OPT_V_ENUM, OPT_NAMEOPT,
      OPT_VERBOSE
  } OPTION_CHOICE;
  
  const OPTIONS verify_options[] = {
      {OPT_HELP_STR, 1, '-', "Usage: %s [options] cert.pem...\n"},
      {OPT_HELP_STR, 1, '-', "Valid options are:\n"},
      {"help", OPT_HELP, '-', "Display this summary"},
      {"verbose", OPT_VERBOSE, '-',
          "Print extra information about the operations being performed."},
      {"CApath", OPT_CAPATH, '/', "A directory of trusted certificates"},
      {"CAfile", OPT_CAFILE, '<', "A file of trusted certificates"},
      {"no-CAfile", OPT_NOCAFILE, '-',
       "Do not load the default certificates file"},
      {"no-CApath", OPT_NOCAPATH, '-',
       "Do not load certificates from the default certificates directory"},
      {"untrusted", OPT_UNTRUSTED, '<', "A file of untrusted certificates"},
      {"trusted", OPT_TRUSTED, '<', "A file of trusted certificates"},
      {"CRLfile", OPT_CRLFILE, '<',
          "File containing one or more CRL's (in PEM format) to load"},
      {"crl_download", OPT_CRL_DOWNLOAD, '-',
          "Attempt to download CRL information for this certificate"},
      {"show_chain", OPT_SHOW_CHAIN, '-',
          "Display information about the certificate chain"},
      {"nameopt", OPT_NAMEOPT, 's', "Various certificate name options"},
      OPT_V_OPTIONS,
  #ifndef OPENSSL_NO_ENGINE
      {"engine", OPT_ENGINE, 's', "Use engine, possibly a hardware device"},
  #endif
      {NULL}
  };
  
  int verify_main(int argc, char **argv)
  {
      ENGINE *e = NULL;
      STACK_OF(X509) *untrusted = NULL, *trusted = NULL;
      STACK_OF(X509_CRL) *crls = NULL;
      X509_STORE *store = NULL;
      X509_VERIFY_PARAM *vpm = NULL;
      const char *prog, *CApath = NULL, *CAfile = NULL;
      int noCApath = 0, noCAfile = 0;
      int vpmtouched = 0, crl_download = 0, show_chain = 0, i = 0, ret = 1;
      OPTION_CHOICE o;
  
      if ((vpm = X509_VERIFY_PARAM_new()) == NULL)
          goto end;
  
      prog = opt_init(argc, argv, verify_options);
      while ((o = opt_next()) != OPT_EOF) {
          switch (o) {
          case OPT_EOF:
          case OPT_ERR:
              BIO_printf(bio_err, "%s: Use -help for summary.\n", prog);
              goto end;
          case OPT_HELP:
              opt_help(verify_options);
              BIO_printf(bio_err, "Recognized usages:\n");
              for (i = 0; i < X509_PURPOSE_get_count(); i++) {
                  X509_PURPOSE *ptmp;
                  ptmp = X509_PURPOSE_get0(i);
                  BIO_printf(bio_err, "\t%-10s\t%s\n",
                          X509_PURPOSE_get0_sname(ptmp),
                          X509_PURPOSE_get0_name(ptmp));
              }
  
              BIO_printf(bio_err, "Recognized verify names:\n");
              for (i = 0; i < X509_VERIFY_PARAM_get_count(); i++) {
                  const X509_VERIFY_PARAM *vptmp;
                  vptmp = X509_VERIFY_PARAM_get0(i);
                  BIO_printf(bio_err, "\t%-10s\n",
                          X509_VERIFY_PARAM_get0_name(vptmp));
              }
              ret = 0;
              goto end;
          case OPT_V_CASES:
              if (!opt_verify(o, vpm))
                  goto end;
              vpmtouched++;
              break;
          case OPT_CAPATH:
              CApath = opt_arg();
              break;
          case OPT_CAFILE:
              CAfile = opt_arg();
              break;
          case OPT_NOCAPATH:
              noCApath = 1;
              break;
          case OPT_NOCAFILE:
              noCAfile = 1;
              break;
          case OPT_UNTRUSTED:
              /* Zero or more times */
              if (!load_certs(opt_arg(), &untrusted, FORMAT_PEM, NULL,
                              "untrusted certificates"))
                  goto end;
              break;
          case OPT_TRUSTED:
              /* Zero or more times */
              noCAfile = 1;
              noCApath = 1;
              if (!load_certs(opt_arg(), &trusted, FORMAT_PEM, NULL,
                              "trusted certificates"))
                  goto end;
              break;
          case OPT_CRLFILE:
              /* Zero or more times */
              if (!load_crls(opt_arg(), &crls, FORMAT_PEM, NULL,
                             "other CRLs"))
                  goto end;
              break;
          case OPT_CRL_DOWNLOAD:
              crl_download = 1;
              break;
          case OPT_ENGINE:
              if ((e = setup_engine(opt_arg(), 0)) == NULL) {
                  /* Failure message already displayed */
                  goto end;
              }
              break;
          case OPT_SHOW_CHAIN:
              show_chain = 1;
              break;
          case OPT_NAMEOPT:
              if (!set_nameopt(opt_arg()))
                  goto end;
              break;
          case OPT_VERBOSE:
              v_verbose = 1;
              break;
          }
      }
      argc = opt_num_rest();
      argv = opt_rest();
      if (trusted != NULL && (CAfile || CApath)) {
          BIO_printf(bio_err,
                     "%s: Cannot use -trusted with -CAfile or -CApath\n",
                     prog);
          goto end;
      }
  
      if ((store = setup_verify(CAfile, CApath, noCAfile, noCApath)) == NULL)
          goto end;
      X509_STORE_set_verify_cb(store, cb);
  
      if (vpmtouched)
          X509_STORE_set1_param(store, vpm);
  
      ERR_clear_error();
  
      if (crl_download)
          store_setup_crl_download(store);
  
      ret = 0;
      if (argc < 1) {
          if (check(store, NULL, untrusted, trusted, crls, show_chain) != 1)
              ret = -1;
      } else {
          for (i = 0; i < argc; i++)
              if (check(store, argv[i], untrusted, trusted, crls,
                        show_chain) != 1)
                  ret = -1;
      }
  
   end:
      X509_VERIFY_PARAM_free(vpm);
      X509_STORE_free(store);
      sk_X509_pop_free(untrusted, X509_free);
      sk_X509_pop_free(trusted, X509_free);
      sk_X509_CRL_pop_free(crls, X509_CRL_free);
      release_engine(e);
      return (ret < 0 ? 2 : ret);
  }
  
  static int check(X509_STORE *ctx, const char *file,
                   STACK_OF(X509) *uchain, STACK_OF(X509) *tchain,
                   STACK_OF(X509_CRL) *crls, int show_chain)
  {
      X509 *x = NULL;
      int i = 0, ret = 0;
      X509_STORE_CTX *csc;
      STACK_OF(X509) *chain = NULL;
      int num_untrusted;
  
      x = load_cert(file, FORMAT_PEM, "certificate file");
      if (x == NULL)
          goto end;
  
      csc = X509_STORE_CTX_new();
      if (csc == NULL) {
          printf("error %s: X.509 store context allocation failed\n",
                 (file == NULL) ? "stdin" : file);
          goto end;
      }
  
      X509_STORE_set_flags(ctx, vflags);
      if (!X509_STORE_CTX_init(csc, ctx, x, uchain)) {
          printf("error %s: X.509 store context initialization failed\n",
                 (file == NULL) ? "stdin" : file);
          goto end;
      }
      if (tchain != NULL)
          X509_STORE_CTX_set0_trusted_stack(csc, tchain);
      if (crls != NULL)
          X509_STORE_CTX_set0_crls(csc, crls);
      i = X509_verify_cert(csc);
      if (i > 0 && X509_STORE_CTX_get_error(csc) == X509_V_OK) {
          printf("%s: OK\n", (file == NULL) ? "stdin" : file);
          ret = 1;
          if (show_chain) {
              int j;
  
              chain = X509_STORE_CTX_get1_chain(csc);
              num_untrusted = X509_STORE_CTX_get_num_untrusted(csc);
              printf("Chain:\n");
              for (j = 0; j < sk_X509_num(chain); j++) {
                  X509 *cert = sk_X509_value(chain, j);
                  printf("depth=%d: ", j);
                  X509_NAME_print_ex_fp(stdout,
                                        X509_get_subject_name(cert),
                                        0, get_nameopt());
                  if (j < num_untrusted)
                      printf(" (untrusted)");
                  printf("\n");
              }
              sk_X509_pop_free(chain, X509_free);
          }
      } else {
          printf("error %s: verification failed\n", (file == NULL) ? "stdin" : file);
      }
      X509_STORE_CTX_free(csc);
  
   end:
      if (i <= 0)
          ERR_print_errors(bio_err);
      X509_free(x);
  
      return ret;
  }
  
  static int cb(int ok, X509_STORE_CTX *ctx)
  {
      int cert_error = X509_STORE_CTX_get_error(ctx);
      X509 *current_cert = X509_STORE_CTX_get_current_cert(ctx);
  
      if (!ok) {
          if (current_cert != NULL) {
              X509_NAME_print_ex(bio_err,
                              X509_get_subject_name(current_cert),
                              0, get_nameopt());
              BIO_printf(bio_err, "\n");
          }
          BIO_printf(bio_err, "%serror %d at %d depth lookup: %s\n",
                 X509_STORE_CTX_get0_parent_ctx(ctx) ? "[CRL path] " : "",
                 cert_error,
                 X509_STORE_CTX_get_error_depth(ctx),
                 X509_verify_cert_error_string(cert_error));
          switch (cert_error) {
          case X509_V_ERR_NO_EXPLICIT_POLICY:
              policies_print(ctx);
              /* fall thru */
          case X509_V_ERR_CERT_HAS_EXPIRED:
  
              /*
               * since we are just checking the certificates, it is ok if they
               * are self signed. But we should still warn the user.
               */
          case X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT:
              /* Continue after extension errors too */
          case X509_V_ERR_INVALID_CA:
          case X509_V_ERR_INVALID_NON_CA:
          case X509_V_ERR_PATH_LENGTH_EXCEEDED:
          case X509_V_ERR_INVALID_PURPOSE:
          case X509_V_ERR_CRL_HAS_EXPIRED:
          case X509_V_ERR_CRL_NOT_YET_VALID:
          case X509_V_ERR_UNHANDLED_CRITICAL_EXTENSION:
              ok = 1;
          }
  
          return ok;
  
      }
      if (cert_error == X509_V_OK && ok == 2)
          policies_print(ctx);
      if (!v_verbose)
          ERR_clear_error();
      return (ok);
  }
  