git.distorted.org.uk Git - u/mdw/putty/blob - unix/uxstore.c

   1 /*
   2  * uxstore.c: Unix-specific implementation of the interface defined
   3  * in storage.h.
   4  */
   5
   6 #include <stdio.h>
   7 #include <stdlib.h>
   8 #include <string.h>
   9 #include <assert.h>
  10 #include <errno.h>
  11 #include <ctype.h>
  12 #include <limits.h>
  13 #include <unistd.h>
  14 #include <fcntl.h>
  15 #include <dirent.h>
  16 #include <sys/stat.h>
  17 #include <sys/types.h>
  18 #include <pwd.h>
  19 #include "putty.h"
  20 #include "storage.h"
  21 #include "tree234.h"
  22
  23 #ifdef PATH_MAX
  24 #define FNLEN PATH_MAX
  25 #else
  26 #define FNLEN 1024 /* XXX */
  27 #endif
  28
  29 enum {
  30     INDEX_DIR, INDEX_HOSTKEYS, INDEX_HOSTKEYS_TMP, INDEX_RANDSEED,
  31     INDEX_SESSIONDIR, INDEX_SESSION,
  32 };
  33
  34 static const char hex[16] = "0123456789ABCDEF";
  35
  36 static char *mungestr(const char *in)
  37 {
  38     char *out, *ret;
  39
  40     if (!in || !*in)
  41         in = "Default Settings";
  42
  43     ret = out = snewn(3*strlen(in)+1, char);
  44
  45     while (*in) {
  46         /*
  47          * There are remarkably few punctuation characters that
  48          * aren't shell-special in some way or likely to be used as
  49          * separators in some file format or another! Hence we use
  50          * opt-in for safe characters rather than opt-out for
  51          * specific unsafe ones...
  52          */
  53         if (*in!='+' && *in!='-' && *in!='.' && *in!='@' && *in!='_' &&
  54             !(*in >= '0' && *in <= '9') &&
  55             !(*in >= 'A' && *in <= 'Z') &&
  56             !(*in >= 'a' && *in <= 'z')) {
  57             *out++ = '%';
  58             *out++ = hex[((unsigned char) *in) >> 4];
  59             *out++ = hex[((unsigned char) *in) & 15];
  60         } else
  61             *out++ = *in;
  62         in++;
  63     }
  64     *out = '\0';
  65     return ret;
  66 }
  67
  68 static char *unmungestr(const char *in)
  69 {
  70     char *out, *ret;
  71     out = ret = snewn(strlen(in)+1, char);
  72     while (*in) {
  73         if (*in == '%' && in[1] && in[2]) {
  74             int i, j;
  75
  76             i = in[1] - '0';
  77             i -= (i > 9 ? 7 : 0);
  78             j = in[2] - '0';
  79             j -= (j > 9 ? 7 : 0);
  80
  81             *out++ = (i << 4) + j;
  82             in += 3;
  83         } else {
  84             *out++ = *in++;
  85         }
  86     }
  87     *out = '\0';
  88     return ret;
  89 }
  90
  91 static char *make_filename(int index, const char *subname)
  92 {
  93     char *env, *tmp, *ret;
  94
  95     /*
  96      * Allow override of the PuTTY configuration location, and of
  97      * specific subparts of it, by means of environment variables.
  98      */
  99     if (index == INDEX_DIR) {
 100         struct passwd *pwd;
 101
 102         env = getenv("PUTTYDIR");
 103         if (env)
 104             return dupstr(env);
 105         env = getenv("HOME");
 106         if (env)
 107             return dupprintf("%s/.putty", env);
 108         pwd = getpwuid(getuid());
 109         if (pwd && pwd->pw_dir)
 110             return dupprintf("%s/.putty", pwd->pw_dir);
 111         return dupstr("/.putty");
 112     }
 113     if (index == INDEX_SESSIONDIR) {
 114         env = getenv("PUTTYSESSIONS");
 115         if (env)
 116             return dupstr(env);
 117         tmp = make_filename(INDEX_DIR, NULL);
 118         ret = dupprintf("%s/sessions", tmp);
 119         sfree(tmp);
 120         return ret;
 121     }
 122     if (index == INDEX_SESSION) {
 123         char *munged = mungestr(subname);
 124         tmp = make_filename(INDEX_SESSIONDIR, NULL);
 125         ret = dupprintf("%s/%s", tmp, munged);
 126         sfree(tmp);
 127         sfree(munged);
 128         return ret;
 129     }
 130     if (index == INDEX_HOSTKEYS) {
 131         env = getenv("PUTTYSSHHOSTKEYS");
 132         if (env)
 133             return dupstr(env);
 134         tmp = make_filename(INDEX_DIR, NULL);
 135         ret = dupprintf("%s/sshhostkeys", tmp);
 136         sfree(tmp);
 137         return ret;
 138     }
 139     if (index == INDEX_HOSTKEYS_TMP) {
 140         tmp = make_filename(INDEX_HOSTKEYS, NULL);
 141         ret = dupprintf("%s.tmp", tmp);
 142         sfree(tmp);
 143         return ret;
 144     }
 145     if (index == INDEX_RANDSEED) {
 146         env = getenv("PUTTYRANDOMSEED");
 147         if (env)
 148             return dupstr(env);
 149         tmp = make_filename(INDEX_DIR, NULL);
 150         ret = dupprintf("%s/randomseed", tmp);
 151         sfree(tmp);
 152         return ret;
 153     }
 154     tmp = make_filename(INDEX_DIR, NULL);
 155     ret = dupprintf("%s/ERROR", tmp);
 156     sfree(tmp);
 157     return ret;
 158 }
 159
 160 void *open_settings_w(const char *sessionname, char **errmsg)
 161 {
 162     char *filename;
 163     FILE *fp;
 164
 165     *errmsg = NULL;
 166
 167     /*
 168      * Start by making sure the .putty directory and its sessions
 169      * subdir actually exist. Ignore error returns from mkdir since
 170      * they're perfectly likely to be `already exists', and any
 171      * other error will trip us up later on so there's no real need
 172      * to catch it now.
 173      */
 174     filename = make_filename(INDEX_SESSIONDIR, NULL);
 175     if (mkdir(filename, 0700) != 0) {
 176         char *filename2 = make_filename(INDEX_DIR, NULL);
 177         mkdir(filename2, 0700);
 178         sfree(filename2);
 179         mkdir(filename, 0700);
 180     }
 181     sfree(filename);
 182
 183     filename = make_filename(INDEX_SESSION, sessionname);
 184     fp = fopen(filename, "w");
 185     if (!fp) {
 186         *errmsg = dupprintf("Unable to create %s: %s",
 187                             filename, strerror(errno));
 188         sfree(filename);
 189         return NULL;                   /* can't open */
 190     }
 191     sfree(filename);
 192     return fp;
 193 }
 194
 195 void write_setting_s(void *handle, const char *key, const char *value)
 196 {
 197     FILE *fp = (FILE *)handle;
 198     fprintf(fp, "%s=%s\n", key, value);
 199 }
 200
 201 void write_setting_i(void *handle, const char *key, int value)
 202 {
 203     FILE *fp = (FILE *)handle;
 204     fprintf(fp, "%s=%d\n", key, value);
 205 }
 206
 207 void close_settings_w(void *handle)
 208 {
 209     FILE *fp = (FILE *)handle;
 210     fclose(fp);
 211 }
 212
 213 /*
 214  * Reading settings, for the moment, is done by retrieving X
 215  * resources from the X display. When we introduce disk files, I
 216  * think what will happen is that the X resources will override
 217  * PuTTY's inbuilt defaults, but that the disk files will then
 218  * override those. This isn't optimal, but it's the best I can
 219  * immediately work out.
 220  * FIXME: the above comment is a bit out of date. Did it happen?
 221  */
 222
 223 struct skeyval {
 224     const char *key;
 225     const char *value;
 226 };
 227
 228 static tree234 *xrmtree = NULL;
 229
 230 int keycmp(void *av, void *bv)
 231 {
 232     struct skeyval *a = (struct skeyval *)av;
 233     struct skeyval *b = (struct skeyval *)bv;
 234     return strcmp(a->key, b->key);
 235 }
 236
 237 void provide_xrm_string(char *string)
 238 {
 239     char *p, *q, *key;
 240     struct skeyval *xrms, *ret;
 241
 242     p = q = strchr(string, ':');
 243     if (!q) {
 244         fprintf(stderr, "pterm: expected a colon in resource string"
 245                 " \"%s\"\n", string);
 246         return;
 247     }
 248     q++;
 249     while (p > string && p[-1] != '.' && p[-1] != '*')
 250         p--;
 251     xrms = snew(struct skeyval);
 252     key = snewn(q-p, char);
 253     memcpy(key, p, q-p);
 254     key[q-p-1] = '\0';
 255     xrms->key = key;
 256     while (*q && isspace((unsigned char)*q))
 257         q++;
 258     xrms->value = dupstr(q);
 259
 260     if (!xrmtree)
 261         xrmtree = newtree234(keycmp);
 262
 263     ret = add234(xrmtree, xrms);
 264     if (ret) {
 265         /* Override an existing string. */
 266         del234(xrmtree, ret);
 267         add234(xrmtree, xrms);
 268     }
 269 }
 270
 271 const char *get_setting(const char *key)
 272 {
 273     struct skeyval tmp, *ret;
 274     tmp.key = key;
 275     if (xrmtree) {
 276         ret = find234(xrmtree, &tmp, NULL);
 277         if (ret)
 278             return ret->value;
 279     }
 280     return x_get_default(key);
 281 }
 282
 283 void *open_settings_r(const char *sessionname)
 284 {
 285     char *filename;
 286     FILE *fp;
 287     char *line;
 288     tree234 *ret;
 289
 290     filename = make_filename(INDEX_SESSION, sessionname);
 291     fp = fopen(filename, "r");
 292     sfree(filename);
 293     if (!fp)
 294         return NULL;                   /* can't open */
 295
 296     ret = newtree234(keycmp);
 297
 298     while ( (line = fgetline(fp)) ) {
 299         char *value = strchr(line, '=');
 300         struct skeyval *kv;
 301
 302         if (!value) {
 303             sfree(line);
 304             continue;
 305         }
 306         *value++ = '\0';
 307         value[strcspn(value, "\r\n")] = '\0';   /* trim trailing NL */
 308
 309         kv = snew(struct skeyval);
 310         kv->key = dupstr(line);
 311         kv->value = dupstr(value);
 312         add234(ret, kv);
 313
 314         sfree(line);
 315     }
 316
 317     fclose(fp);
 318
 319     return ret;
 320 }
 321
 322 char *read_setting_s(void *handle, const char *key)
 323 {
 324     tree234 *tree = (tree234 *)handle;
 325     const char *val;
 326     struct skeyval tmp, *kv;
 327
 328     tmp.key = key;
 329     if (tree != NULL &&
 330         (kv = find234(tree, &tmp, NULL)) != NULL) {
 331         val = kv->value;
 332         assert(val != NULL);
 333     } else
 334         val = get_setting(key);
 335
 336     if (!val)
 337         return NULL;
 338     else
 339         return dupstr(val);
 340 }
 341
 342 int read_setting_i(void *handle, const char *key, int defvalue)
 343 {
 344     tree234 *tree = (tree234 *)handle;
 345     const char *val;
 346     struct skeyval tmp, *kv;
 347
 348     tmp.key = key;
 349     if (tree != NULL &&
 350         (kv = find234(tree, &tmp, NULL)) != NULL) {
 351         val = kv->value;
 352         assert(val != NULL);
 353     } else
 354         val = get_setting(key);
 355
 356     if (!val)
 357         return defvalue;
 358     else
 359         return atoi(val);
 360 }
 361
 362 FontSpec *read_setting_fontspec(void *handle, const char *name)
 363 {
 364     /*
 365      * In GTK1-only PuTTY, we used to store font names simply as a
 366      * valid X font description string (logical or alias), under a
 367      * bare key such as "Font".
 368      *
 369      * In GTK2 PuTTY, we have a prefix system where "client:"
 370      * indicates a Pango font and "server:" an X one; existing
 371      * configuration needs to be reinterpreted as having the
 372      * "server:" prefix, so we change the storage key from the
 373      * provided name string (e.g. "Font") to a suffixed one
 374      * ("FontName").
 375      */
 376     char *suffname = dupcat(name, "Name", NULL);
 377     char *tmp;
 378
 379     if ((tmp = read_setting_s(handle, suffname)) != NULL) {
 380         FontSpec *fs = fontspec_new(tmp);
 381         sfree(suffname);
 382         sfree(tmp);
 383         return fs;                     /* got new-style name */
 384     }
 385     sfree(suffname);
 386
 387     /* Fall back to old-style name. */
 388     tmp = read_setting_s(handle, name);
 389     if (tmp && *tmp) {
 390         char *tmp2 = dupcat("server:", tmp, NULL);
 391         FontSpec *fs = fontspec_new(tmp2);
 392         sfree(tmp2);
 393         sfree(tmp);
 394         return fs;
 395     } else {
 396         sfree(tmp);
 397         return NULL;
 398     }
 399 }
 400 Filename *read_setting_filename(void *handle, const char *name)
 401 {
 402     char *tmp = read_setting_s(handle, name);
 403     if (tmp) {
 404         Filename *ret = filename_from_str(tmp);
 405         sfree(tmp);
 406         return ret;
 407     } else
 408         return NULL;
 409 }
 410
 411 void write_setting_fontspec(void *handle, const char *name, FontSpec *fs)
 412 {
 413     /*
 414      * read_setting_fontspec had to handle two cases, but when
 415      * writing our settings back out we simply always generate the
 416      * new-style name.
 417      */
 418     char *suffname = dupcat(name, "Name", NULL);
 419     write_setting_s(handle, suffname, fs->name);
 420     sfree(suffname);
 421 }
 422 void write_setting_filename(void *handle, const char *name, Filename *result)
 423 {
 424     write_setting_s(handle, name, result->path);
 425 }
 426
 427 void close_settings_r(void *handle)
 428 {
 429     tree234 *tree = (tree234 *)handle;
 430     struct skeyval *kv;
 431
 432     if (!tree)
 433         return;
 434
 435     while ( (kv = index234(tree, 0)) != NULL) {
 436         del234(tree, kv);
 437         sfree((char *)kv->key);
 438         sfree((char *)kv->value);
 439         sfree(kv);
 440     }
 441
 442     freetree234(tree);
 443 }
 444
 445 void del_settings(const char *sessionname)
 446 {
 447     char *filename;
 448     filename = make_filename(INDEX_SESSION, sessionname);
 449     unlink(filename);
 450     sfree(filename);
 451 }
 452
 453 void *enum_settings_start(void)
 454 {
 455     DIR *dp;
 456     char *filename;
 457
 458     filename = make_filename(INDEX_SESSIONDIR, NULL);
 459     dp = opendir(filename);
 460     sfree(filename);
 461
 462     return dp;
 463 }
 464
 465 char *enum_settings_next(void *handle, char *buffer, int buflen)
 466 {
 467     DIR *dp = (DIR *)handle;
 468     struct dirent *de;
 469     struct stat st;
 470     char *fullpath;
 471     int maxlen, thislen, len;
 472     char *unmunged;
 473
 474     fullpath = make_filename(INDEX_SESSIONDIR, NULL);
 475     maxlen = len = strlen(fullpath);
 476
 477     while ( (de = readdir(dp)) != NULL ) {
 478         thislen = len + 1 + strlen(de->d_name);
 479         if (maxlen < thislen) {
 480             maxlen = thislen;
 481             fullpath = sresize(fullpath, maxlen+1, char);
 482         }
 483         fullpath[len] = '/';
 484         strncpy(fullpath+len+1, de->d_name, thislen - (len+1));
 485         fullpath[thislen] = '\0';
 486
 487         if (stat(fullpath, &st) < 0 || !S_ISREG(st.st_mode))
 488             continue;                  /* try another one */
 489
 490         unmunged = unmungestr(de->d_name);
 491         strncpy(buffer, unmunged, buflen);
 492         buffer[buflen-1] = '\0';
 493         sfree(unmunged);
 494         sfree(fullpath);
 495         return buffer;
 496     }
 497
 498     sfree(fullpath);
 499     return NULL;
 500 }
 501
 502 void enum_settings_finish(void *handle)
 503 {
 504     DIR *dp = (DIR *)handle;
 505     closedir(dp);
 506 }
 507
 508 /*
 509  * Lines in the host keys file are of the form
 510  *
 511  *   type@port:hostname keydata
 512  *
 513  * e.g.
 514  *
 515  *   rsa@22:foovax.example.org 0x23,0x293487364395345345....2343
 516  */
 517 int verify_host_key(const char *hostname, int port,
 518                     const char *keytype, const char *key)
 519 {
 520     FILE *fp;
 521     char *filename;
 522     char *line;
 523     int ret;
 524
 525     filename = make_filename(INDEX_HOSTKEYS, NULL);
 526     fp = fopen(filename, "r");
 527     sfree(filename);
 528     if (!fp)
 529         return 1;                      /* key does not exist */
 530
 531     ret = 1;
 532     while ( (line = fgetline(fp)) ) {
 533         int i;
 534         char *p = line;
 535         char porttext[20];
 536
 537         line[strcspn(line, "\n")] = '\0';   /* strip trailing newline */
 538
 539         i = strlen(keytype);
 540         if (strncmp(p, keytype, i))
 541             goto done;
 542         p += i;
 543
 544         if (*p != '@')
 545             goto done;
 546         p++;
 547
 548         sprintf(porttext, "%d", port);
 549         i = strlen(porttext);
 550         if (strncmp(p, porttext, i))
 551             goto done;
 552         p += i;
 553
 554         if (*p != ':')
 555             goto done;
 556         p++;
 557
 558         i = strlen(hostname);
 559         if (strncmp(p, hostname, i))
 560             goto done;
 561         p += i;
 562
 563         if (*p != ' ')
 564             goto done;
 565         p++;
 566
 567         /*
 568          * Found the key. Now just work out whether it's the right
 569          * one or not.
 570          */
 571         if (!strcmp(p, key))
 572             ret = 0;                   /* key matched OK */
 573         else
 574             ret = 2;                   /* key mismatch */
 575
 576         done:
 577         sfree(line);
 578         if (ret != 1)
 579             break;
 580     }
 581
 582     fclose(fp);
 583     return ret;
 584 }
 585
 586 void store_host_key(const char *hostname, int port,
 587                     const char *keytype, const char *key)
 588 {
 589     FILE *rfp, *wfp;
 590     char *newtext, *line;
 591     int headerlen;
 592     char *filename, *tmpfilename;
 593
 594     /*
 595      * Open both the old file and a new file.
 596      */
 597     tmpfilename = make_filename(INDEX_HOSTKEYS_TMP, NULL);
 598     wfp = fopen(tmpfilename, "w");
 599     if (!wfp && errno == ENOENT) {
 600         char *dir;
 601
 602         dir = make_filename(INDEX_DIR, NULL);
 603         if (mkdir(dir, 0700) < 0) {
 604             char *msg = dupprintf("Unable to store host key: mkdir(\"%s\") "
 605                                   "returned '%s'", dir, strerror(errno));
 606             nonfatal(msg);
 607             sfree(dir);
 608             sfree(tmpfilename);
 609             return;
 610         }
 611         sfree(dir);
 612
 613         wfp = fopen(tmpfilename, "w");
 614     }
 615     if (!wfp) {
 616         char *msg = dupprintf("Unable to store host key: open(\"%s\") "
 617                               "returned '%s'", tmpfilename, strerror(errno));
 618         nonfatal(msg);
 619         sfree(tmpfilename);
 620         return;
 621     }
 622     filename = make_filename(INDEX_HOSTKEYS, NULL);
 623     rfp = fopen(filename, "r");
 624
 625     newtext = dupprintf("%s@%d:%s %s\n", keytype, port, hostname, key);
 626     headerlen = 1 + strcspn(newtext, " ");   /* count the space too */
 627
 628     /*
 629      * Copy all lines from the old file to the new one that _don't_
 630      * involve the same host key identifier as the one we're adding.
 631      */
 632     if (rfp) {
 633         while ( (line = fgetline(rfp)) ) {
 634             if (strncmp(line, newtext, headerlen))
 635                 fputs(line, wfp);
 636             sfree(line);
 637         }
 638         fclose(rfp);
 639     }
 640
 641     /*
 642      * Now add the new line at the end.
 643      */
 644     fputs(newtext, wfp);
 645
 646     fclose(wfp);
 647
 648     rename(tmpfilename, filename);
 649
 650     sfree(tmpfilename);
 651     sfree(filename);
 652     sfree(newtext);
 653 }
 654
 655 void read_random_seed(noise_consumer_t consumer)
 656 {
 657     int fd;
 658     char *fname;
 659
 660     fname = make_filename(INDEX_RANDSEED, NULL);
 661     fd = open(fname, O_RDONLY);
 662     sfree(fname);
 663     if (fd >= 0) {
 664         char buf[512];
 665         int ret;
 666         while ( (ret = read(fd, buf, sizeof(buf))) > 0)
 667             consumer(buf, ret);
 668         close(fd);
 669     }
 670 }
 671
 672 void write_random_seed(void *data, int len)
 673 {
 674     int fd;
 675     char *fname;
 676
 677     fname = make_filename(INDEX_RANDSEED, NULL);
 678     /*
 679      * Don't truncate the random seed file if it already exists; if
 680      * something goes wrong half way through writing it, it would
 681      * be better to leave the old data there than to leave it empty.
 682      */
 683     fd = open(fname, O_CREAT | O_WRONLY, 0600);
 684     if (fd < 0) {
 685         if (errno != ENOENT) {
 686             char *msg = dupprintf("Unable to write random seed: open(\"%s\") "
 687                                   "returned '%s'", fname, strerror(errno));
 688             nonfatal(msg);
 689             sfree(msg);
 690             return;
 691         }
 692         char *dir;
 693
 694         dir = make_filename(INDEX_DIR, NULL);
 695         if (mkdir(dir, 0700) < 0) {
 696             char *msg = dupprintf("Unable to write random seed: mkdir(\"%s\") "
 697                                   "returned '%s'", dir, strerror(errno));
 698             nonfatal(msg);
 699             sfree(msg);
 700             sfree(dir);
 701             return;
 702         }
 703         sfree(dir);
 704
 705         fd = open(fname, O_CREAT | O_WRONLY, 0600);
 706         if (errno != ENOENT) {
 707             char *msg = dupprintf("Unable to write random seed: open(\"%s\") "
 708                                   "returned '%s'", fname, strerror(errno));
 709             nonfatal(msg);
 710             sfree(msg);
 711             return;
 712         }
 713     }
 714
 715     while (len > 0) {
 716         int ret = write(fd, data, len);
 717         if (ret < 0) {
 718             char *msg = dupprintf("Unable to write random seed: write "
 719                                   "returned '%s'", strerror(errno));
 720             nonfatal(msg);
 721             sfree(msg);
 722             break;
 723         }
 724         len -= ret;
 725         data = (char *)data + len;
 726     }
 727
 728     close(fd);
 729     sfree(fname);
 730 }
 731
 732 void cleanup_all(void)
 733 {
 734 }