src/ocsptool-common.c

   1 /*
   2  * Copyright (C) 2012 Free Software Foundation, Inc.
   3  *
   4  * This file is part of GnuTLS.
   5  *
   6  * GnuTLS is free software: you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation, either version 3 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * GnuTLS is distributed in the hope that it will be useful, but
  12  * WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program.  If not, see
  18  * <http://www.gnu.org/licenses/>.
  19  */
  20
  21 #include <config.h>
  22
  23 #include <stdio.h>
  24 #include <stdlib.h>
  25 #include <string.h>
  26 #include <errno.h>
  27
  28 #include <gnutls/gnutls.h>
  29 #include <gnutls/ocsp.h>
  30 #include <gnutls/x509.h>
  31 #include <gnutls/crypto.h>
  32
  33 /* Gnulib portability files. */
  34 #include <error.h>
  35 #include <progname.h>
  36 #include <version-etc.h>
  37 #include <read-file.h>
  38 #include <socket.h>
  39
  40 #include <ocsptool-common.h>
  41
  42 #define MAX_BUF 4*1024
  43 #define HEADER_PATTERN "POST / HTTP/1.1\r\n" \
  44   "Host: %s\r\n" \
  45   "Accept: */*\r\n" \
  46   "Content-Type: application/ocsp-request\r\n" \
  47   "Content-Length: %u\r\n" \
  48   "Connection: close\r\n\r\n"
  49 static char buffer[MAX_BUF + 1];
  50
  51 /* returns the host part of a URL */
  52 static const char* host_from_url(const char* url, unsigned int* port)
  53 {
  54 static char hostname[512];
  55 char * p;
  56
  57   *port = 0;
  58
  59   if ((p=strstr(url, "http://")) != NULL)
  60     {
  61       snprintf(hostname, sizeof(hostname), "%s", p+7);
  62       p = strchr(hostname, '/');
  63       if (p != NULL) *p = 0;
  64
  65       p = strchr(hostname, ':');
  66       if (p != NULL) {
  67         *p = 0;
  68         *port = atoi(p+1);
  69       }
  70
  71       return hostname;
  72     }
  73   else
  74     {
  75       return url;
  76     }
  77 }
  78
  79 void
  80 _generate_request (gnutls_x509_crt_t cert, gnutls_x509_crt_t issuer,
  81                    gnutls_datum_t * rdata, int nonce)
  82 {
  83   gnutls_ocsp_req_t req;
  84   int ret;
  85
  86   ret = gnutls_ocsp_req_init (&req);
  87   if (ret < 0)
  88     error (EXIT_FAILURE, 0, "ocsp_req_init: %s", gnutls_strerror (ret));
  89
  90   ret = gnutls_ocsp_req_add_cert (req, GNUTLS_DIG_SHA1,
  91                                       issuer, cert);
  92   if (ret < 0)
  93     error (EXIT_FAILURE, 0, "ocsp_req_add_cert: %s", gnutls_strerror (ret));
  94
  95   if (nonce)
  96     {
  97       unsigned char noncebuf[23];
  98       gnutls_datum_t nonce = { noncebuf, sizeof (noncebuf) };
  99
 100       ret = gnutls_rnd (GNUTLS_RND_RANDOM, nonce.data, nonce.size);
 101       if (ret < 0)
 102         error (EXIT_FAILURE, 0, "gnutls_rnd: %s", gnutls_strerror (ret));
 103
 104       ret = gnutls_ocsp_req_set_nonce (req, 0, &nonce);
 105       if (ret < 0)
 106         error (EXIT_FAILURE, 0, "ocsp_req_set_nonce: %s",
 107                gnutls_strerror (ret));
 108     }
 109
 110   ret = gnutls_ocsp_req_export (req, rdata);
 111   if (ret != 0)
 112     error (EXIT_FAILURE, 0, "ocsp_req_export: %s", gnutls_strerror (ret));
 113
 114   gnutls_ocsp_req_deinit (req);
 115   return;
 116 }
 117
 118 static size_t get_data(void *buffer, size_t size, size_t nmemb, void *userp)
 119 {
 120 gnutls_datum_t *ud = userp;
 121
 122   size *= nmemb;
 123
 124   ud->data = realloc(ud->data, size+ud->size);
 125   if (ud->data == NULL)
 126     {
 127       fprintf(stderr, "Not enough memory for the request\n");
 128       exit(1);
 129     }
 130
 131   memcpy(&ud->data[ud->size], buffer, size);
 132   ud->size += size;
 133
 134   return size;
 135 }
 136
 137 /* Returns 0 on ok, and -1 on error */
 138 int send_ocsp_request(const char* server,
 139                        gnutls_x509_crt_t cert, gnutls_x509_crt_t issuer,
 140                        gnutls_datum_t * resp_data, int nonce)
 141 {
 142 gnutls_datum_t ud;
 143 int ret;
 144 gnutls_datum_t req;
 145 char* url = (void*)server;
 146 char headers[1024];
 147 char service[16];
 148 unsigned char * p;
 149 const char *hostname;
 150 unsigned int headers_size = 0, port;
 151 socket_st hd;
 152
 153   sockets_init ();
 154
 155   if (url == NULL)
 156     {
 157       /* try to read URL from issuer certificate */
 158       gnutls_datum_t data;
 159
 160       ret = gnutls_x509_crt_get_authority_info_access(cert, 0,
 161                                   GNUTLS_IA_OCSP_URI, &data, NULL);
 162
 163       if (ret < 0)
 164         ret = gnutls_x509_crt_get_authority_info_access(issuer, 0,
 165                                     GNUTLS_IA_OCSP_URI, &data, NULL);
 166       if (ret < 0)
 167         {
 168           fprintf(stderr, "Cannot find URL from issuer: %s\n", gnutls_strerror(ret));
 169           return -1;
 170         }
 171
 172       url = malloc(data.size+1);
 173       memcpy(url, data.data, data.size);
 174       url[data.size] = 0;
 175
 176       gnutls_free(data.data);
 177     }
 178
 179   hostname = host_from_url(url, &port);
 180   if (port != 0)
 181     snprintf(service, sizeof(service), "%u", port);
 182   else strcpy(service, "80");
 183
 184   fprintf(stderr, "Connecting to OCSP server: %s...\n", hostname);
 185
 186   memset(&ud, 0, sizeof(ud));
 187
 188   _generate_request(cert, issuer, &req, nonce);
 189
 190   snprintf(headers, sizeof(headers), HEADER_PATTERN, hostname, (unsigned int)req.size);
 191   headers_size = strlen(headers);
 192
 193   socket_open(&hd, hostname, service, 0);
 194   socket_connect (&hd);
 195
 196   socket_send(&hd, headers, headers_size);
 197   socket_send(&hd, req.data, req.size);
 198
 199   do {
 200     ret = socket_recv(&hd, buffer, sizeof(buffer));
 201     if (ret > 0) get_data(buffer, ret, 1, &ud);
 202   } while(ret > 0);
 203
 204   if (ret < 0 || ud.size == 0)
 205     {
 206       perror("recv");
 207       return -1;
 208     }
 209
 210   socket_bye(&hd);
 211
 212   p = memmem(ud.data, ud.size, "\r\n\r\n", 4);
 213   if (p == NULL)
 214     {
 215       fprintf(stderr, "Cannot interpret HTTP response\n");
 216       return -1;
 217     }
 218
 219   p += 4;
 220   resp_data->size = ud.size - (p - ud.data);
 221   resp_data->data = malloc(resp_data->size);
 222   if (resp_data->data == NULL)
 223     return -1;
 224
 225   memcpy(resp_data->data, p, resp_data->size);
 226
 227   free(ud.data);
 228
 229   return 0;
 230 }
 231
 232 void
 233 print_ocsp_verify_res (unsigned int output)
 234 {
 235   int comma = 0;
 236
 237   if (output)
 238     {
 239       printf ("Failure");
 240       comma = 1;
 241     }
 242   else
 243     {
 244       printf ("Success");
 245       comma = 1;
 246     }
 247
 248   if (output & GNUTLS_OCSP_VERIFY_SIGNER_NOT_FOUND)
 249     {
 250       if (comma)
 251         printf (", ");
 252       printf ("Signer cert not found");
 253       comma = 1;
 254     }
 255
 256   if (output & GNUTLS_OCSP_VERIFY_SIGNER_KEYUSAGE_ERROR)
 257     {
 258       if (comma)
 259         printf (", ");
 260       printf ("Signer cert keyusage error");
 261       comma = 1;
 262     }
 263
 264   if (output & GNUTLS_OCSP_VERIFY_UNTRUSTED_SIGNER)
 265     {
 266       if (comma)
 267         printf (", ");
 268       printf ("Signer cert is not trusted");
 269       comma = 1;
 270     }
 271
 272   if (output & GNUTLS_OCSP_VERIFY_INSECURE_ALGORITHM)
 273     {
 274       if (comma)
 275         printf (", ");
 276       printf ("Insecure algorithm");
 277       comma = 1;
 278     }
 279
 280   if (output & GNUTLS_OCSP_VERIFY_SIGNATURE_FAILURE)
 281     {
 282       if (comma)
 283         printf (", ");
 284       printf ("Signature failure");
 285       comma = 1;
 286     }
 287
 288   if (output & GNUTLS_OCSP_VERIFY_CERT_NOT_ACTIVATED)
 289     {
 290       if (comma)
 291         printf (", ");
 292       printf ("Signer cert not yet activated");
 293       comma = 1;
 294     }
 295
 296   if (output & GNUTLS_OCSP_VERIFY_CERT_EXPIRED)
 297     {
 298       if (comma)
 299         printf (", ");
 300       printf ("Signer cert expired");
 301       comma = 1;
 302     }
 303 }
 304
 305 /* Returns:
 306  *  0: certificate is revoked
 307  *  1: certificate is ok
 308  *  -1: dunno
 309  */
 310 int
 311 check_ocsp_response (gnutls_x509_crt_t issuer,
 312                      gnutls_datum_t *data)
 313 {
 314   gnutls_ocsp_resp_t resp;
 315   int ret;
 316   unsigned int status, cert_status;
 317   time_t rtime, ttime;
 318
 319   ret = gnutls_ocsp_resp_init (&resp);
 320   if (ret < 0)
 321     error (EXIT_FAILURE, 0, "ocsp_resp_init: %s", gnutls_strerror (ret));
 322
 323   ret = gnutls_ocsp_resp_import (resp, data);
 324   if (ret < 0)
 325     error (EXIT_FAILURE, 0, "importing response: %s", gnutls_strerror (ret));
 326
 327   ret = gnutls_ocsp_resp_verify_direct( resp, issuer, &status, 0);
 328   if (ret < 0)
 329     error (EXIT_FAILURE, 0, "gnutls_ocsp_resp_verify_direct: %s",
 330       gnutls_strerror (ret));
 331
 332   if (status != 0)
 333     {
 334       printf ("*** Verifying OCSP Response: ");
 335       print_ocsp_verify_res (status);
 336       printf (".\n");
 337     }
 338
 339   /* do not print revocation data if response was not verified */
 340   if (status != 0)
 341     {
 342       ret = -1;
 343       goto cleanup;
 344     }
 345
 346   ret = gnutls_ocsp_resp_get_single(resp, 0, NULL, NULL, NULL, NULL,
 347         &cert_status, &ttime, NULL, &rtime, NULL);
 348   if (ret < 0)
 349     error (EXIT_FAILURE, 0, "reading response: %s", gnutls_strerror (ret));
 350
 351   if (cert_status == GNUTLS_OCSP_CERT_REVOKED)
 352     {
 353       printf("*** Certificate was revoked at %s", ctime(&rtime));
 354       ret = 0;
 355       goto cleanup;
 356     }
 357
 358   printf("- OCSP server flags certificate not revoked as of %s", ctime(&ttime));
 359   ret = 1;
 360 cleanup:
 361   gnutls_ocsp_resp_deinit (resp);
 362
 363   return ret;
 364 }
 365