mdw@git.distorted.org.uk Git - sgt/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.
 170      */
 171     filename = make_filename(INDEX_DIR, NULL);
 172     if (mkdir(filename, 0700) < 0 && errno != EEXIST) {
 173         *errmsg = dupprintf("Unable to save session: mkdir(\"%s\") "
 174                             "returned '%s'", filename, strerror(errno));
 175         sfree(filename);
 176         return NULL;
 177     }
 178     sfree(filename);
 179
 180     filename = make_filename(INDEX_SESSIONDIR, NULL);
 181     if (mkdir(filename, 0700) < 0 && errno != EEXIST) {
 182         *errmsg = dupprintf("Unable to save session: mkdir(\"%s\") "
 183                             "returned '%s'", filename, strerror(errno));
 184         sfree(filename);
 185         return NULL;
 186     }
 187     sfree(filename);
 188
 189     filename = make_filename(INDEX_SESSION, sessionname);
 190     fp = fopen(filename, "w");
 191     if (!fp) {
 192         *errmsg = dupprintf("Unable to save session: open(\"%s\") "
 193                             "returned '%s'", filename, strerror(errno));
 194         sfree(filename);
 195         return NULL;                   /* can't open */
 196     }
 197     sfree(filename);
 198     return fp;
 199 }
 200
 201 void write_setting_s(void *handle, const char *key, const char *value)
 202 {
 203     FILE *fp = (FILE *)handle;
 204     fprintf(fp, "%s=%s\n", key, value);
 205 }
 206
 207 void write_setting_i(void *handle, const char *key, int value)
 208 {
 209     FILE *fp = (FILE *)handle;
 210     fprintf(fp, "%s=%d\n", key, value);
 211 }
 212
 213 void close_settings_w(void *handle)
 214 {
 215     FILE *fp = (FILE *)handle;
 216     fclose(fp);
 217 }
 218
 219 /*
 220  * Reading settings, for the moment, is done by retrieving X
 221  * resources from the X display. When we introduce disk files, I
 222  * think what will happen is that the X resources will override
 223  * PuTTY's inbuilt defaults, but that the disk files will then
 224  * override those. This isn't optimal, but it's the best I can
 225  * immediately work out.
 226  * FIXME: the above comment is a bit out of date. Did it happen?
 227  */
 228
 229 struct skeyval {
 230     const char *key;
 231     const char *value;
 232 };
 233
 234 static tree234 *xrmtree = NULL;
 235
 236 int keycmp(void *av, void *bv)
 237 {
 238     struct skeyval *a = (struct skeyval *)av;
 239     struct skeyval *b = (struct skeyval *)bv;
 240     return strcmp(a->key, b->key);
 241 }
 242
 243 void provide_xrm_string(char *string)
 244 {
 245     char *p, *q, *key;
 246     struct skeyval *xrms, *ret;
 247
 248     p = q = strchr(string, ':');
 249     if (!q) {
 250         fprintf(stderr, "pterm: expected a colon in resource string"
 251                 " \"%s\"\n", string);
 252         return;
 253     }
 254     q++;
 255     while (p > string && p[-1] != '.' && p[-1] != '*')
 256         p--;
 257     xrms = snew(struct skeyval);
 258     key = snewn(q-p, char);
 259     memcpy(key, p, q-p);
 260     key[q-p-1] = '\0';
 261     xrms->key = key;
 262     while (*q && isspace((unsigned char)*q))
 263         q++;
 264     xrms->value = dupstr(q);
 265
 266     if (!xrmtree)
 267         xrmtree = newtree234(keycmp);
 268
 269     ret = add234(xrmtree, xrms);
 270     if (ret) {
 271         /* Override an existing string. */
 272         del234(xrmtree, ret);
 273         add234(xrmtree, xrms);
 274     }
 275 }
 276
 277 const char *get_setting(const char *key)
 278 {
 279     struct skeyval tmp, *ret;
 280     tmp.key = key;
 281     if (xrmtree) {
 282         ret = find234(xrmtree, &tmp, NULL);
 283         if (ret)
 284             return ret->value;
 285     }
 286     return x_get_default(key);
 287 }
 288
 289 void *open_settings_r(const char *sessionname)
 290 {
 291     char *filename;
 292     FILE *fp;
 293     char *line;
 294     tree234 *ret;
 295
 296     filename = make_filename(INDEX_SESSION, sessionname);
 297     fp = fopen(filename, "r");
 298     sfree(filename);
 299     if (!fp)
 300         return NULL;                   /* can't open */
 301
 302     ret = newtree234(keycmp);
 303
 304     while ( (line = fgetline(fp)) ) {
 305         char *value = strchr(line, '=');
 306         struct skeyval *kv;
 307
 308         if (!value) {
 309             sfree(line);
 310             continue;
 311         }
 312         *value++ = '\0';
 313         value[strcspn(value, "\r\n")] = '\0';   /* trim trailing NL */
 314
 315         kv = snew(struct skeyval);
 316         kv->key = dupstr(line);
 317         kv->value = dupstr(value);
 318         add234(ret, kv);
 319
 320         sfree(line);
 321     }
 322
 323     fclose(fp);
 324
 325     return ret;
 326 }
 327
 328 char *read_setting_s(void *handle, const char *key)
 329 {
 330     tree234 *tree = (tree234 *)handle;
 331     const char *val;
 332     struct skeyval tmp, *kv;
 333
 334     tmp.key = key;
 335     if (tree != NULL &&
 336         (kv = find234(tree, &tmp, NULL)) != NULL) {
 337         val = kv->value;
 338         assert(val != NULL);
 339     } else
 340         val = get_setting(key);
 341
 342     if (!val)
 343         return NULL;
 344     else
 345         return dupstr(val);
 346 }
 347
 348 int read_setting_i(void *handle, const char *key, int defvalue)
 349 {
 350     tree234 *tree = (tree234 *)handle;
 351     const char *val;
 352     struct skeyval tmp, *kv;
 353
 354     tmp.key = key;
 355     if (tree != NULL &&
 356         (kv = find234(tree, &tmp, NULL)) != NULL) {
 357         val = kv->value;
 358         assert(val != NULL);
 359     } else
 360         val = get_setting(key);
 361
 362     if (!val)
 363         return defvalue;
 364     else
 365         return atoi(val);
 366 }
 367
 368 FontSpec *read_setting_fontspec(void *handle, const char *name)
 369 {
 370     /*
 371      * In GTK1-only PuTTY, we used to store font names simply as a
 372      * valid X font description string (logical or alias), under a
 373      * bare key such as "Font".
 374      *
 375      * In GTK2 PuTTY, we have a prefix system where "client:"
 376      * indicates a Pango font and "server:" an X one; existing
 377      * configuration needs to be reinterpreted as having the
 378      * "server:" prefix, so we change the storage key from the
 379      * provided name string (e.g. "Font") to a suffixed one
 380      * ("FontName").
 381      */
 382     char *suffname = dupcat(name, "Name", NULL);
 383     char *tmp;
 384
 385     if ((tmp = read_setting_s(handle, suffname)) != NULL) {
 386         FontSpec *fs = fontspec_new(tmp);
 387         sfree(suffname);
 388         sfree(tmp);
 389         return fs;                     /* got new-style name */
 390     }
 391     sfree(suffname);
 392
 393     /* Fall back to old-style name. */
 394     tmp = read_setting_s(handle, name);
 395     if (tmp && *tmp) {
 396         char *tmp2 = dupcat("server:", tmp, NULL);
 397         FontSpec *fs = fontspec_new(tmp2);
 398         sfree(tmp2);
 399         sfree(tmp);
 400         return fs;
 401     } else {
 402         sfree(tmp);
 403         return NULL;
 404     }
 405 }
 406 Filename *read_setting_filename(void *handle, const char *name)
 407 {
 408     char *tmp = read_setting_s(handle, name);
 409     if (tmp) {
 410         Filename *ret = filename_from_str(tmp);
 411         sfree(tmp);
 412         return ret;
 413     } else
 414         return NULL;
 415 }
 416
 417 void write_setting_fontspec(void *handle, const char *name, FontSpec *fs)
 418 {
 419     /*
 420      * read_setting_fontspec had to handle two cases, but when
 421      * writing our settings back out we simply always generate the
 422      * new-style name.
 423      */
 424     char *suffname = dupcat(name, "Name", NULL);
 425     write_setting_s(handle, suffname, fs->name);
 426     sfree(suffname);
 427 }
 428 void write_setting_filename(void *handle, const char *name, Filename *result)
 429 {
 430     write_setting_s(handle, name, result->path);
 431 }
 432
 433 void close_settings_r(void *handle)
 434 {
 435     tree234 *tree = (tree234 *)handle;
 436     struct skeyval *kv;
 437
 438     if (!tree)
 439         return;
 440
 441     while ( (kv = index234(tree, 0)) != NULL) {
 442         del234(tree, kv);
 443         sfree((char *)kv->key);
 444         sfree((char *)kv->value);
 445         sfree(kv);
 446     }
 447
 448     freetree234(tree);
 449 }
 450
 451 void del_settings(const char *sessionname)
 452 {
 453     char *filename;
 454     filename = make_filename(INDEX_SESSION, sessionname);
 455     unlink(filename);
 456     sfree(filename);
 457 }
 458
 459 void *enum_settings_start(void)
 460 {
 461     DIR *dp;
 462     char *filename;
 463
 464     filename = make_filename(INDEX_SESSIONDIR, NULL);
 465     dp = opendir(filename);
 466     sfree(filename);
 467
 468     return dp;
 469 }
 470
 471 char *enum_settings_next(void *handle, char *buffer, int buflen)
 472 {
 473     DIR *dp = (DIR *)handle;
 474     struct dirent *de;
 475     struct stat st;
 476     char *fullpath;
 477     int maxlen, thislen, len;
 478     char *unmunged;
 479
 480     fullpath = make_filename(INDEX_SESSIONDIR, NULL);
 481     maxlen = len = strlen(fullpath);
 482
 483     while ( (de = readdir(dp)) != NULL ) {
 484         thislen = len + 1 + strlen(de->d_name);
 485         if (maxlen < thislen) {
 486             maxlen = thislen;
 487             fullpath = sresize(fullpath, maxlen+1, char);
 488         }
 489         fullpath[len] = '/';
 490         strncpy(fullpath+len+1, de->d_name, thislen - (len+1));
 491         fullpath[thislen] = '\0';
 492
 493         if (stat(fullpath, &st) < 0 || !S_ISREG(st.st_mode))
 494             continue;                  /* try another one */
 495
 496         unmunged = unmungestr(de->d_name);
 497         strncpy(buffer, unmunged, buflen);
 498         buffer[buflen-1] = '\0';
 499         sfree(unmunged);
 500         sfree(fullpath);
 501         return buffer;
 502     }
 503
 504     sfree(fullpath);
 505     return NULL;
 506 }
 507
 508 void enum_settings_finish(void *handle)
 509 {
 510     DIR *dp = (DIR *)handle;
 511     closedir(dp);
 512 }
 513
 514 /*
 515  * Lines in the host keys file are of the form
 516  *
 517  *   type@port:hostname keydata
 518  *
 519  * e.g.
 520  *
 521  *   rsa@22:foovax.example.org 0x23,0x293487364395345345....2343
 522  */
 523 int verify_host_key(const char *hostname, int port,
 524                     const char *keytype, const char *key)
 525 {
 526     FILE *fp;
 527     char *filename;
 528     char *line;
 529     int ret;
 530
 531     filename = make_filename(INDEX_HOSTKEYS, NULL);
 532     fp = fopen(filename, "r");
 533     sfree(filename);
 534     if (!fp)
 535         return 1;                      /* key does not exist */
 536
 537     ret = 1;
 538     while ( (line = fgetline(fp)) ) {
 539         int i;
 540         char *p = line;
 541         char porttext[20];
 542
 543         line[strcspn(line, "\n")] = '\0';   /* strip trailing newline */
 544
 545         i = strlen(keytype);
 546         if (strncmp(p, keytype, i))
 547             goto done;
 548         p += i;
 549
 550         if (*p != '@')
 551             goto done;
 552         p++;
 553
 554         sprintf(porttext, "%d", port);
 555         i = strlen(porttext);
 556         if (strncmp(p, porttext, i))
 557             goto done;
 558         p += i;
 559
 560         if (*p != ':')
 561             goto done;
 562         p++;
 563
 564         i = strlen(hostname);
 565         if (strncmp(p, hostname, i))
 566             goto done;
 567         p += i;
 568
 569         if (*p != ' ')
 570             goto done;
 571         p++;
 572
 573         /*
 574          * Found the key. Now just work out whether it's the right
 575          * one or not.
 576          */
 577         if (!strcmp(p, key))
 578             ret = 0;                   /* key matched OK */
 579         else
 580             ret = 2;                   /* key mismatch */
 581
 582         done:
 583         sfree(line);
 584         if (ret != 1)
 585             break;
 586     }
 587
 588     fclose(fp);
 589     return ret;
 590 }
 591
 592 void store_host_key(const char *hostname, int port,
 593                     const char *keytype, const char *key)
 594 {
 595     FILE *rfp, *wfp;
 596     char *newtext, *line;
 597     int headerlen;
 598     char *filename, *tmpfilename;
 599
 600     /*
 601      * Open both the old file and a new file.
 602      */
 603     tmpfilename = make_filename(INDEX_HOSTKEYS_TMP, NULL);
 604     wfp = fopen(tmpfilename, "w");
 605     if (!wfp && errno == ENOENT) {
 606         char *dir;
 607
 608         dir = make_filename(INDEX_DIR, NULL);
 609         if (mkdir(dir, 0700) < 0) {
 610             char *msg = dupprintf("Unable to store host key: mkdir(\"%s\") "
 611                                   "returned '%s'", dir, strerror(errno));
 612             nonfatal(msg);
 613             sfree(dir);
 614             sfree(tmpfilename);
 615             return;
 616         }
 617         sfree(dir);
 618
 619         wfp = fopen(tmpfilename, "w");
 620     }
 621     if (!wfp) {
 622         char *msg = dupprintf("Unable to store host key: open(\"%s\") "
 623                               "returned '%s'", tmpfilename, strerror(errno));
 624         nonfatal(msg);
 625         sfree(tmpfilename);
 626         return;
 627     }
 628     filename = make_filename(INDEX_HOSTKEYS, NULL);
 629     rfp = fopen(filename, "r");
 630
 631     newtext = dupprintf("%s@%d:%s %s\n", keytype, port, hostname, key);
 632     headerlen = 1 + strcspn(newtext, " ");   /* count the space too */
 633
 634     /*
 635      * Copy all lines from the old file to the new one that _don't_
 636      * involve the same host key identifier as the one we're adding.
 637      */
 638     if (rfp) {
 639         while ( (line = fgetline(rfp)) ) {
 640             if (strncmp(line, newtext, headerlen))
 641                 fputs(line, wfp);
 642             sfree(line);
 643         }
 644         fclose(rfp);
 645     }
 646
 647     /*
 648      * Now add the new line at the end.
 649      */
 650     fputs(newtext, wfp);
 651
 652     fclose(wfp);
 653
 654     rename(tmpfilename, filename);
 655
 656     sfree(tmpfilename);
 657     sfree(filename);
 658     sfree(newtext);
 659 }
 660
 661 void read_random_seed(noise_consumer_t consumer)
 662 {
 663     int fd;
 664     char *fname;
 665
 666     fname = make_filename(INDEX_RANDSEED, NULL);
 667     fd = open(fname, O_RDONLY);
 668     sfree(fname);
 669     if (fd >= 0) {
 670         char buf[512];
 671         int ret;
 672         while ( (ret = read(fd, buf, sizeof(buf))) > 0)
 673             consumer(buf, ret);
 674         close(fd);
 675     }
 676 }
 677
 678 void write_random_seed(void *data, int len)
 679 {
 680     int fd;
 681     char *fname;
 682
 683     fname = make_filename(INDEX_RANDSEED, NULL);
 684     /*
 685      * Don't truncate the random seed file if it already exists; if
 686      * something goes wrong half way through writing it, it would
 687      * be better to leave the old data there than to leave it empty.
 688      */
 689     fd = open(fname, O_CREAT | O_WRONLY, 0600);
 690     if (fd < 0) {
 691         if (errno != ENOENT) {
 692             char *msg = dupprintf("Unable to write random seed: open(\"%s\") "
 693                                   "returned '%s'", fname, strerror(errno));
 694             nonfatal(msg);
 695             sfree(msg);
 696             sfree(fname);
 697             return;
 698         }
 699         char *dir;
 700
 701         dir = make_filename(INDEX_DIR, NULL);
 702         if (mkdir(dir, 0700) < 0) {
 703             char *msg = dupprintf("Unable to write random seed: mkdir(\"%s\") "
 704                                   "returned '%s'", dir, strerror(errno));
 705             nonfatal(msg);
 706             sfree(msg);
 707             sfree(fname);
 708             sfree(dir);
 709             return;
 710         }
 711         sfree(dir);
 712
 713         fd = open(fname, O_CREAT | O_WRONLY, 0600);
 714         if (errno != ENOENT) {
 715             char *msg = dupprintf("Unable to write random seed: open(\"%s\") "
 716                                   "returned '%s'", fname, strerror(errno));
 717             nonfatal(msg);
 718             sfree(msg);
 719             sfree(fname);
 720             return;
 721         }
 722     }
 723
 724     while (len > 0) {
 725         int ret = write(fd, data, len);
 726         if (ret < 0) {
 727             char *msg = dupprintf("Unable to write random seed: write "
 728                                   "returned '%s'", strerror(errno));
 729             nonfatal(msg);
 730             sfree(msg);
 731             break;
 732         }
 733         len -= ret;
 734         data = (char *)data + len;
 735     }
 736
 737     close(fd);
 738     sfree(fname);
 739 }
 740
 741 void cleanup_all(void)
 742 {
 743 }