src/common/ssl_certificate.c

   1 /*
   2  * Sylpheed -- a GTK+ based, lightweight, and fast e-mail client
   3  * Copyright (C) 1999-2006 Hiroyuki Yamamoto
   4  * This file Copyright (C) 2002-2005 Colin Leroy <colin@colino.net>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU 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, write to the Free Software
  18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  19  */
  20
  21 #ifdef HAVE_CONFIG_H
  22 #  include "config.h"
  23 #endif
  24
  25 #if USE_OPENSSL
  26
  27 #include <openssl/ssl.h>
  28 #include <glib.h>
  29 #include <glib/gi18n.h>
  30
  31 #include "ssl_certificate.h"
  32 #include "utils.h"
  33 #include "log.h"
  34 #include "socket.h"
  35 #include "hooks.h"
  36
  37 static GHashTable *warned_expired = NULL;
  38
  39 static SSLCertificate *ssl_certificate_new_lookup(X509 *x509_cert, gchar *host, gushort port, gboolean lookup);
  40
  41 /* from Courier */
  42 time_t asn1toTime(ASN1_TIME *asn1Time)
  43 {
  44         struct tm tm;
  45         int offset;
  46
  47         if (asn1Time == NULL || asn1Time->length < 13)
  48                 return 0;
  49
  50         memset(&tm, 0, sizeof(tm));
  51
  52 #define N2(n)   ((asn1Time->data[n]-'0')*10 + asn1Time->data[(n)+1]-'0')
  53
  54 #define CPY(f,n) (tm.f=N2(n))
  55
  56         CPY(tm_year,0);
  57
  58         if(tm.tm_year < 50)
  59                 tm.tm_year += 100; /* Sux */
  60
  61         CPY(tm_mon, 2);
  62         --tm.tm_mon;
  63         CPY(tm_mday, 4);
  64         CPY(tm_hour, 6);
  65         CPY(tm_min, 8);
  66         CPY(tm_sec, 10);
  67
  68         offset=0;
  69
  70         if (asn1Time->data[12] != 'Z')
  71         {
  72                 if (asn1Time->length < 17)
  73                         return 0;
  74
  75                 offset=N2(13)*3600+N2(15)*60;
  76
  77                 if (asn1Time->data[12] == '-')
  78                         offset= -offset;
  79         }
  80
  81 #undef N2
  82 #undef CPY
  83
  84         return mktime(&tm)-offset;
  85 }
  86
  87 static char * get_fqdn(char *host)
  88 {
  89         struct hostent *hp;
  90
  91         if (host == NULL || strlen(host) == 0)
  92                 return g_strdup("");
  93
  94         hp = my_gethostbyname(host);
  95         if (hp == NULL)
  96                 return g_strdup(host); /*caller should free*/
  97         else
  98                 return g_strdup(hp->h_name);
  99 }
 100
 101 char * readable_fingerprint(unsigned char *src, int len)
 102 {
 103         int i=0;
 104         char * ret;
 105
 106         if (src == NULL)
 107                 return NULL;
 108         ret = g_strdup("");
 109         while (i < len) {
 110                 char *tmp2;
 111                 if(i>0)
 112                         tmp2 = g_strdup_printf("%s:%02X", ret, src[i]);
 113                 else
 114                         tmp2 = g_strdup_printf("%02X", src[i]);
 115                 g_free(ret);
 116                 ret = g_strdup(tmp2);
 117                 g_free(tmp2);
 118                 i++;
 119         }
 120         return ret;
 121 }
 122
 123 SSLCertificate *ssl_certificate_new(X509 *x509_cert, gchar *host, gushort port)
 124 {
 125         return ssl_certificate_new_lookup(x509_cert, host, port, TRUE);
 126 }
 127
 128 static SSLCertificate *ssl_certificate_new_lookup(X509 *x509_cert, gchar *host, gushort port, gboolean lookup)
 129 {
 130         SSLCertificate *cert = g_new0(SSLCertificate, 1);
 131
 132         if (host == NULL || x509_cert == NULL) {
 133                 ssl_certificate_destroy(cert);
 134                 return NULL;
 135         }
 136         cert->x509_cert = X509_dup(x509_cert);
 137         if (lookup)
 138                 cert->host = get_fqdn(host);
 139         else
 140                 cert->host = g_strdup(host);
 141         cert->port = port;
 142         return cert;
 143 }
 144
 145 static void ssl_certificate_save (SSLCertificate *cert)
 146 {
 147         gchar *file, *port;
 148         FILE *fp;
 149
 150         file = g_strconcat(get_rc_dir(), G_DIR_SEPARATOR_S,
 151                           "certs", G_DIR_SEPARATOR_S, NULL);
 152
 153         if (!is_dir_exist(file))
 154                 make_dir_hier(file);
 155         g_free(file);
 156
 157         port = g_strdup_printf("%d", cert->port);
 158         file = g_strconcat(get_rc_dir(), G_DIR_SEPARATOR_S,
 159                           "certs", G_DIR_SEPARATOR_S,
 160                           cert->host, ".", port, ".cert", NULL);
 161
 162         g_free(port);
 163         fp = g_fopen(file, "wb");
 164         if (fp == NULL) {
 165                 g_free(file);
 166                 debug_print("Can't save certificate !\n");
 167                 return;
 168         }
 169         i2d_X509_fp(fp, cert->x509_cert);
 170         g_free(file);
 171         fclose(fp);
 172
 173 }
 174
 175 char* ssl_certificate_to_string(SSLCertificate *cert)
 176 {
 177         char *ret, buf[100];
 178         char *issuer_commonname, *issuer_location, *issuer_organization;
 179         char *subject_commonname, *subject_location, *subject_organization;
 180         char *fingerprint, *sig_status;
 181         unsigned int n;
 182         unsigned char md[EVP_MAX_MD_SIZE];
 183
 184         /* issuer */
 185         if (X509_NAME_get_text_by_NID(X509_get_issuer_name(cert->x509_cert),
 186                                        NID_commonName, buf, 100) >= 0)
 187                 issuer_commonname = g_strdup(buf);
 188         else
 189                 issuer_commonname = g_strdup(_("<not in certificate>"));
 190         if (X509_NAME_get_text_by_NID(X509_get_issuer_name(cert->x509_cert),
 191                                        NID_localityName, buf, 100) >= 0) {
 192                 issuer_location = g_strdup(buf);
 193                 if (X509_NAME_get_text_by_NID(X509_get_issuer_name(cert->x509_cert),
 194                                        NID_countryName, buf, 100) >= 0)
 195                         issuer_location = g_strconcat(issuer_location,", ",buf, NULL);
 196         } else if (X509_NAME_get_text_by_NID(X509_get_issuer_name(cert->x509_cert),
 197                                        NID_countryName, buf, 100) >= 0)
 198                 issuer_location = g_strdup(buf);
 199         else
 200                 issuer_location = g_strdup(_("<not in certificate>"));
 201
 202         if (X509_NAME_get_text_by_NID(X509_get_issuer_name(cert->x509_cert),
 203                                        NID_organizationName, buf, 100) >= 0)
 204                 issuer_organization = g_strdup(buf);
 205         else
 206                 issuer_organization = g_strdup(_("<not in certificate>"));
 207
 208         /* subject */
 209         if (X509_NAME_get_text_by_NID(X509_get_subject_name(cert->x509_cert),
 210                                        NID_commonName, buf, 100) >= 0)
 211                 subject_commonname = g_strdup(buf);
 212         else
 213                 subject_commonname = g_strdup(_("<not in certificate>"));
 214         if (X509_NAME_get_text_by_NID(X509_get_subject_name(cert->x509_cert),
 215                                        NID_localityName, buf, 100) >= 0) {
 216                 subject_location = g_strdup(buf);
 217                 if (X509_NAME_get_text_by_NID(X509_get_subject_name(cert->x509_cert),
 218                                        NID_countryName, buf, 100) >= 0)
 219                         subject_location = g_strconcat(subject_location,", ",buf, NULL);
 220         } else if (X509_NAME_get_text_by_NID(X509_get_subject_name(cert->x509_cert),
 221                                        NID_countryName, buf, 100) >= 0)
 222                 subject_location = g_strdup(buf);
 223         else
 224                 subject_location = g_strdup(_("<not in certificate>"));
 225
 226         if (X509_NAME_get_text_by_NID(X509_get_subject_name(cert->x509_cert),
 227                                        NID_organizationName, buf, 100) >= 0)
 228                 subject_organization = g_strdup(buf);
 229         else
 230                 subject_organization = g_strdup(_("<not in certificate>"));
 231
 232         /* fingerprint */
 233         X509_digest(cert->x509_cert, EVP_md5(), md, &n);
 234         fingerprint = readable_fingerprint(md, (int)n);
 235
 236         /* signature */
 237         sig_status = ssl_certificate_check_signer(cert->x509_cert);
 238
 239         ret = g_strdup_printf(_("  Owner: %s (%s) in %s\n  Signed by: %s (%s) in %s\n  Fingerprint: %s\n  Signature status: %s"),
 240                                 subject_commonname, subject_organization, subject_location,
 241                                 issuer_commonname, issuer_organization, issuer_location,
 242                                 fingerprint,
 243                                 (sig_status==NULL ? "correct":sig_status));
 244
 245         g_free(issuer_commonname);
 246         g_free(issuer_location);
 247         g_free(issuer_organization);
 248         g_free(subject_commonname);
 249         g_free(subject_location);
 250         g_free(subject_organization);
 251         g_free(fingerprint);
 252         g_free(sig_status);
 253         return ret;
 254 }
 255
 256 void ssl_certificate_destroy(SSLCertificate *cert)
 257 {
 258         if (cert == NULL)
 259                 return;
 260
 261         if (cert->x509_cert)
 262                 X509_free(cert->x509_cert);
 263         g_free(cert->host);
 264         g_free(cert);
 265         cert = NULL;
 266 }
 267
 268 void ssl_certificate_delete_from_disk(SSLCertificate *cert)
 269 {
 270         gchar *buf;
 271         gchar *file;
 272         buf = g_strdup_printf("%d", cert->port);
 273         file = g_strconcat(get_rc_dir(), G_DIR_SEPARATOR_S,
 274                           "certs", G_DIR_SEPARATOR_S,
 275                           cert->host, ".", buf, ".cert", NULL);
 276         g_unlink (file);
 277         g_free(buf);
 278         g_free(file);
 279 }
 280
 281 SSLCertificate *ssl_certificate_find (gchar *host, gushort port)
 282 {
 283         return ssl_certificate_find_lookup (host, port, TRUE);
 284 }
 285
 286 SSLCertificate *ssl_certificate_find_lookup (gchar *host, gushort port, gboolean lookup)
 287 {
 288         gchar *file;
 289         gchar *buf;
 290         gchar *fqdn_host;
 291         SSLCertificate *cert = NULL;
 292         X509 *tmp_x509;
 293         FILE *fp;
 294
 295         if (lookup)
 296                 fqdn_host = get_fqdn(host);
 297         else
 298                 fqdn_host = g_strdup(host);
 299
 300         buf = g_strdup_printf("%d", port);
 301         file = g_strconcat(get_rc_dir(), G_DIR_SEPARATOR_S,
 302                           "certs", G_DIR_SEPARATOR_S,
 303                           fqdn_host, ".", buf, ".cert", NULL);
 304
 305         g_free(buf);
 306         fp = g_fopen(file, "rb");
 307         if (fp == NULL) {
 308                 g_free(file);
 309                 g_free(fqdn_host);
 310                 return NULL;
 311         }
 312
 313
 314         if ((tmp_x509 = d2i_X509_fp(fp, 0)) != NULL) {
 315                 cert = ssl_certificate_new_lookup(tmp_x509, fqdn_host, port, lookup);
 316                 X509_free(tmp_x509);
 317         }
 318         fclose(fp);
 319         g_free(file);
 320         g_free(fqdn_host);
 321
 322         return cert;
 323 }
 324
 325 static gboolean ssl_certificate_compare (SSLCertificate *cert_a, SSLCertificate *cert_b)
 326 {
 327         if (cert_a == NULL || cert_b == NULL)
 328                 return FALSE;
 329         else if (!X509_cmp(cert_a->x509_cert, cert_b->x509_cert))
 330                 return TRUE;
 331         else
 332                 return FALSE;
 333 }
 334
 335 char *ssl_certificate_check_signer (X509 *cert)
 336 {
 337         X509_STORE_CTX store_ctx;
 338         X509_STORE *store;
 339         char *err_msg = NULL;
 340
 341         store = X509_STORE_new();
 342         if (store == NULL) {
 343                 printf("Can't create X509_STORE\n");
 344                 return NULL;
 345         }
 346         if (!X509_STORE_set_default_paths(store)) {
 347                 X509_STORE_free (store);
 348                 return g_strdup(_("Couldn't load X509 default paths"));
 349         }
 350
 351         X509_STORE_CTX_init (&store_ctx, store, cert, NULL);
 352
 353         if(!X509_verify_cert (&store_ctx)) {
 354                 err_msg = g_strdup(X509_verify_cert_error_string(
 355                                         X509_STORE_CTX_get_error(&store_ctx)));
 356                 debug_print("Can't check signer: %s\n", err_msg);
 357                 X509_STORE_CTX_cleanup (&store_ctx);
 358                 X509_STORE_free (store);
 359                 return err_msg;
 360
 361         }
 362         X509_STORE_CTX_cleanup (&store_ctx);
 363         X509_STORE_free (store);
 364         return NULL;
 365 }
 366
 367 gboolean ssl_certificate_check (X509 *x509_cert, gchar *fqdn, gchar *host, gushort port)
 368 {
 369         SSLCertificate *current_cert = NULL;
 370         SSLCertificate *known_cert;
 371         SSLCertHookData cert_hook_data;
 372         gchar *fqdn_host = NULL;
 373
 374         if (fqdn)
 375                 fqdn_host = g_strdup(fqdn);
 376         else if (host)
 377                 fqdn_host = get_fqdn(host);
 378         else {
 379                 g_warning("no host!\n");
 380                 return FALSE;
 381         }
 382
 383         current_cert = ssl_certificate_new_lookup(x509_cert, fqdn_host, port, FALSE);
 384
 385         if (current_cert == NULL) {
 386                 debug_print("Buggy certificate !\n");
 387                 g_free(fqdn_host);
 388                 return FALSE;
 389         }
 390
 391         known_cert = ssl_certificate_find_lookup (fqdn_host, port, FALSE);
 392
 393         g_free(fqdn_host);
 394
 395         if (known_cert == NULL) {
 396                 cert_hook_data.cert = current_cert;
 397                 cert_hook_data.old_cert = NULL;
 398                 cert_hook_data.expired = FALSE;
 399                 cert_hook_data.accept = FALSE;
 400
 401                 hooks_invoke(SSLCERT_ASK_HOOKLIST, &cert_hook_data);
 402
 403                 if (!cert_hook_data.accept) {
 404                         ssl_certificate_destroy(current_cert);
 405                         return FALSE;
 406                 } else {
 407                         ssl_certificate_save(current_cert);
 408                         ssl_certificate_destroy(current_cert);
 409                         return TRUE;
 410                 }
 411         } else if (!ssl_certificate_compare (current_cert, known_cert)) {
 412                 cert_hook_data.cert = current_cert;
 413                 cert_hook_data.old_cert = known_cert;
 414                 cert_hook_data.expired = FALSE;
 415                 cert_hook_data.accept = FALSE;
 416
 417                 hooks_invoke(SSLCERT_ASK_HOOKLIST, &cert_hook_data);
 418
 419                 if (!cert_hook_data.accept) {
 420                         ssl_certificate_destroy(current_cert);
 421                         ssl_certificate_destroy(known_cert);
 422                         return FALSE;
 423                 } else {
 424                         ssl_certificate_save(current_cert);
 425                         ssl_certificate_destroy(current_cert);
 426                         ssl_certificate_destroy(known_cert);
 427                         return TRUE;
 428                 }
 429         } else if (asn1toTime(X509_get_notAfter(current_cert->x509_cert)) < time(NULL)) {
 430                 gchar *tmp = g_strdup_printf("%s:%d", current_cert->host, current_cert->port);
 431
 432                 if (warned_expired == NULL)
 433                         warned_expired = g_hash_table_new(g_str_hash, g_str_equal);
 434
 435                 if (g_hash_table_lookup(warned_expired, tmp)) {
 436                         g_free(tmp);
 437                         ssl_certificate_destroy(current_cert);
 438                         ssl_certificate_destroy(known_cert);
 439                         return TRUE;
 440                 }
 441
 442                 cert_hook_data.cert = current_cert;
 443                 cert_hook_data.old_cert = NULL;
 444                 cert_hook_data.expired = TRUE;
 445                 cert_hook_data.accept = FALSE;
 446
 447                 hooks_invoke(SSLCERT_ASK_HOOKLIST, &cert_hook_data);
 448
 449                 if (!cert_hook_data.accept) {
 450                         g_free(tmp);
 451                         ssl_certificate_destroy(current_cert);
 452                         ssl_certificate_destroy(known_cert);
 453                         return FALSE;
 454                 } else {
 455                         g_hash_table_insert(warned_expired, tmp, GINT_TO_POINTER(1));
 456                         ssl_certificate_destroy(current_cert);
 457                         ssl_certificate_destroy(known_cert);
 458                         return TRUE;
 459                 }
 460         }
 461
 462         ssl_certificate_destroy(current_cert);
 463         ssl_certificate_destroy(known_cert);
 464         return TRUE;
 465 }
 466
 467 #endif /* USE_OPENSSL */