git.distorted.org.uk Git - u/mdw/putty/blob - windows/winstore.c

   1 /*
   2  * winstore.c: Windows-specific implementation of the interface
   3  * defined in storage.h.
   4  */
   5
   6 #include <stdio.h>
   7 #include <stdlib.h>
   8 #include <limits.h>
   9 #include "putty.h"
  10 #include "storage.h"
  11
  12 #include <shlobj.h>
  13 #ifndef CSIDL_APPDATA
  14 #define CSIDL_APPDATA 0x001a
  15 #endif
  16 #ifndef CSIDL_LOCAL_APPDATA
  17 #define CSIDL_LOCAL_APPDATA 0x001c
  18 #endif
  19
  20 static const char *const reg_jumplist_key = PUTTY_REG_POS "\\Jumplist";
  21 static const char *const reg_jumplist_value = "Recent sessions";
  22 static const char *const puttystr = PUTTY_REG_POS "\\Sessions";
  23
  24 static const char hex[16] = "0123456789ABCDEF";
  25
  26 static int tried_shgetfolderpath = FALSE;
  27 static HMODULE shell32_module = NULL;
  28 DECL_WINDOWS_FUNCTION(static, HRESULT, SHGetFolderPathA,
  29                       (HWND, int, HANDLE, DWORD, LPSTR));
  30
  31 static void mungestr(const char *in, char *out)
  32 {
  33     int candot = 0;
  34
  35     while (*in) {
  36         if (*in == ' ' || *in == '\\' || *in == '*' || *in == '?' ||
  37             *in == '%' || *in < ' ' || *in > '~' || (*in == '.'
  38                                                      && !candot)) {
  39             *out++ = '%';
  40             *out++ = hex[((unsigned char) *in) >> 4];
  41             *out++ = hex[((unsigned char) *in) & 15];
  42         } else
  43             *out++ = *in;
  44         in++;
  45         candot = 1;
  46     }
  47     *out = '\0';
  48     return;
  49 }
  50
  51 static void unmungestr(const char *in, char *out, int outlen)
  52 {
  53     while (*in) {
  54         if (*in == '%' && in[1] && in[2]) {
  55             int i, j;
  56
  57             i = in[1] - '0';
  58             i -= (i > 9 ? 7 : 0);
  59             j = in[2] - '0';
  60             j -= (j > 9 ? 7 : 0);
  61
  62             *out++ = (i << 4) + j;
  63             if (!--outlen)
  64                 return;
  65             in += 3;
  66         } else {
  67             *out++ = *in++;
  68             if (!--outlen)
  69                 return;
  70         }
  71     }
  72     *out = '\0';
  73     return;
  74 }
  75
  76 void *open_settings_w(const char *sessionname, char **errmsg)
  77 {
  78     HKEY subkey1, sesskey;
  79     int ret;
  80     char *p;
  81
  82     *errmsg = NULL;
  83
  84     if (!sessionname || !*sessionname)
  85         sessionname = "Default Settings";
  86
  87     p = snewn(3 * strlen(sessionname) + 1, char);
  88     mungestr(sessionname, p);
  89
  90     ret = RegCreateKey(HKEY_CURRENT_USER, puttystr, &subkey1);
  91     if (ret != ERROR_SUCCESS) {
  92         sfree(p);
  93         *errmsg = dupprintf("Unable to create registry key\n"
  94                             "HKEY_CURRENT_USER\\%s", puttystr);
  95         return NULL;
  96     }
  97     ret = RegCreateKey(subkey1, p, &sesskey);
  98     RegCloseKey(subkey1);
  99     if (ret != ERROR_SUCCESS) {
 100         *errmsg = dupprintf("Unable to create registry key\n"
 101                             "HKEY_CURRENT_USER\\%s\\%s", puttystr, p);
 102         sfree(p);
 103         return NULL;
 104     }
 105     sfree(p);
 106     return (void *) sesskey;
 107 }
 108
 109 void write_setting_s(void *handle, const char *key, const char *value)
 110 {
 111     if (handle)
 112         RegSetValueEx((HKEY) handle, key, 0, REG_SZ, value,
 113                       1 + strlen(value));
 114 }
 115
 116 void write_setting_i(void *handle, const char *key, int value)
 117 {
 118     if (handle)
 119         RegSetValueEx((HKEY) handle, key, 0, REG_DWORD,
 120                       (CONST BYTE *) &value, sizeof(value));
 121 }
 122
 123 void close_settings_w(void *handle)
 124 {
 125     RegCloseKey((HKEY) handle);
 126 }
 127
 128 void *open_settings_r(const char *sessionname)
 129 {
 130     HKEY subkey1, sesskey;
 131     char *p;
 132
 133     if (!sessionname || !*sessionname)
 134         sessionname = "Default Settings";
 135
 136     p = snewn(3 * strlen(sessionname) + 1, char);
 137     mungestr(sessionname, p);
 138
 139     if (RegOpenKey(HKEY_CURRENT_USER, puttystr, &subkey1) != ERROR_SUCCESS) {
 140         sesskey = NULL;
 141     } else {
 142         if (RegOpenKey(subkey1, p, &sesskey) != ERROR_SUCCESS) {
 143             sesskey = NULL;
 144         }
 145         RegCloseKey(subkey1);
 146     }
 147
 148     sfree(p);
 149
 150     return (void *) sesskey;
 151 }
 152
 153 char *read_setting_s(void *handle, const char *key)
 154 {
 155     DWORD type, size;
 156     char *ret;
 157
 158     if (!handle)
 159         return NULL;
 160
 161     /* Find out the type and size of the data. */
 162     if (RegQueryValueEx((HKEY) handle, key, 0,
 163                         &type, NULL, &size) != ERROR_SUCCESS ||
 164         type != REG_SZ)
 165         return NULL;
 166
 167     ret = snewn(size+1, char);
 168     if (RegQueryValueEx((HKEY) handle, key, 0,
 169                         &type, ret, &size) != ERROR_SUCCESS ||
 170         type != REG_SZ) return NULL;
 171
 172     return ret;
 173 }
 174
 175 int read_setting_i(void *handle, const char *key, int defvalue)
 176 {
 177     DWORD type, val, size;
 178     size = sizeof(val);
 179
 180     if (!handle ||
 181         RegQueryValueEx((HKEY) handle, key, 0, &type,
 182                         (BYTE *) &val, &size) != ERROR_SUCCESS ||
 183         size != sizeof(val) || type != REG_DWORD)
 184         return defvalue;
 185     else
 186         return val;
 187 }
 188
 189 FontSpec *read_setting_fontspec(void *handle, const char *name)
 190 {
 191     char *settingname;
 192     char *fontname;
 193     int isbold, height, charset;
 194
 195     fontname = read_setting_s(handle, name);
 196     if (!fontname)
 197         return NULL;
 198
 199     settingname = dupcat(name, "IsBold", NULL);
 200     isbold = read_setting_i(handle, settingname, -1);
 201     sfree(settingname);
 202     if (isbold == -1) return NULL;
 203
 204     settingname = dupcat(name, "CharSet", NULL);
 205     charset = read_setting_i(handle, settingname, -1);
 206     sfree(settingname);
 207     if (charset == -1) return NULL;
 208
 209     settingname = dupcat(name, "Height", NULL);
 210     height = read_setting_i(handle, settingname, INT_MIN);
 211     sfree(settingname);
 212     if (height == INT_MIN) return NULL;
 213
 214     return fontspec_new(fontname, isbold, height, charset);
 215 }
 216
 217 void write_setting_fontspec(void *handle, const char *name, FontSpec *font)
 218 {
 219     char *settingname;
 220
 221     write_setting_s(handle, name, font->name);
 222     settingname = dupcat(name, "IsBold", NULL);
 223     write_setting_i(handle, settingname, font->isbold);
 224     sfree(settingname);
 225     settingname = dupcat(name, "CharSet", NULL);
 226     write_setting_i(handle, settingname, font->charset);
 227     sfree(settingname);
 228     settingname = dupcat(name, "Height", NULL);
 229     write_setting_i(handle, settingname, font->height);
 230     sfree(settingname);
 231 }
 232
 233 int read_setting_filename(void *handle, const char *name, Filename *result)
 234 {
 235     char *tmp = read_setting_s(handle, name);
 236     if (tmp) {
 237         strncpy(result->path, tmp, sizeof(result->path)-1);
 238         result->path[sizeof(result->path)-1] = '\0';
 239         sfree(tmp);
 240         return TRUE;
 241     } else
 242         return FALSE;
 243 }
 244
 245 void write_setting_filename(void *handle, const char *name, Filename result)
 246 {
 247     write_setting_s(handle, name, result.path);
 248 }
 249
 250 void close_settings_r(void *handle)
 251 {
 252     RegCloseKey((HKEY) handle);
 253 }
 254
 255 void del_settings(const char *sessionname)
 256 {
 257     HKEY subkey1;
 258     char *p;
 259
 260     if (RegOpenKey(HKEY_CURRENT_USER, puttystr, &subkey1) != ERROR_SUCCESS)
 261         return;
 262
 263     p = snewn(3 * strlen(sessionname) + 1, char);
 264     mungestr(sessionname, p);
 265     RegDeleteKey(subkey1, p);
 266     sfree(p);
 267
 268     RegCloseKey(subkey1);
 269
 270     remove_session_from_jumplist(sessionname);
 271 }
 272
 273 struct enumsettings {
 274     HKEY key;
 275     int i;
 276 };
 277
 278 void *enum_settings_start(void)
 279 {
 280     struct enumsettings *ret;
 281     HKEY key;
 282
 283     if (RegOpenKey(HKEY_CURRENT_USER, puttystr, &key) != ERROR_SUCCESS)
 284         return NULL;
 285
 286     ret = snew(struct enumsettings);
 287     if (ret) {
 288         ret->key = key;
 289         ret->i = 0;
 290     }
 291
 292     return ret;
 293 }
 294
 295 char *enum_settings_next(void *handle, char *buffer, int buflen)
 296 {
 297     struct enumsettings *e = (struct enumsettings *) handle;
 298     char *otherbuf;
 299     otherbuf = snewn(3 * buflen, char);
 300     if (RegEnumKey(e->key, e->i++, otherbuf, 3 * buflen) == ERROR_SUCCESS) {
 301         unmungestr(otherbuf, buffer, buflen);
 302         sfree(otherbuf);
 303         return buffer;
 304     } else {
 305         sfree(otherbuf);
 306         return NULL;
 307     }
 308 }
 309
 310 void enum_settings_finish(void *handle)
 311 {
 312     struct enumsettings *e = (struct enumsettings *) handle;
 313     RegCloseKey(e->key);
 314     sfree(e);
 315 }
 316
 317 static void hostkey_regname(char *buffer, const char *hostname,
 318                             int port, const char *keytype)
 319 {
 320     int len;
 321     strcpy(buffer, keytype);
 322     strcat(buffer, "@");
 323     len = strlen(buffer);
 324     len += sprintf(buffer + len, "%d:", port);
 325     mungestr(hostname, buffer + strlen(buffer));
 326 }
 327
 328 int verify_host_key(const char *hostname, int port,
 329                     const char *keytype, const char *key)
 330 {
 331     char *otherstr, *regname;
 332     int len;
 333     HKEY rkey;
 334     DWORD readlen;
 335     DWORD type;
 336     int ret, compare;
 337
 338     len = 1 + strlen(key);
 339
 340     /*
 341      * Now read a saved key in from the registry and see what it
 342      * says.
 343      */
 344     otherstr = snewn(len, char);
 345     regname = snewn(3 * (strlen(hostname) + strlen(keytype)) + 15, char);
 346
 347     hostkey_regname(regname, hostname, port, keytype);
 348
 349     if (RegOpenKey(HKEY_CURRENT_USER, PUTTY_REG_POS "\\SshHostKeys",
 350                    &rkey) != ERROR_SUCCESS)
 351         return 1;                      /* key does not exist in registry */
 352
 353     readlen = len;
 354     ret = RegQueryValueEx(rkey, regname, NULL, &type, otherstr, &readlen);
 355
 356     if (ret != ERROR_SUCCESS && ret != ERROR_MORE_DATA &&
 357         !strcmp(keytype, "rsa")) {
 358         /*
 359          * Key didn't exist. If the key type is RSA, we'll try
 360          * another trick, which is to look up the _old_ key format
 361          * under just the hostname and translate that.
 362          */
 363         char *justhost = regname + 1 + strcspn(regname, ":");
 364         char *oldstyle = snewn(len + 10, char); /* safety margin */
 365         readlen = len;
 366         ret = RegQueryValueEx(rkey, justhost, NULL, &type,
 367                               oldstyle, &readlen);
 368
 369         if (ret == ERROR_SUCCESS && type == REG_SZ) {
 370             /*
 371              * The old format is two old-style bignums separated by
 372              * a slash. An old-style bignum is made of groups of
 373              * four hex digits: digits are ordered in sensible
 374              * (most to least significant) order within each group,
 375              * but groups are ordered in silly (least to most)
 376              * order within the bignum. The new format is two
 377              * ordinary C-format hex numbers (0xABCDEFG...XYZ, with
 378              * A nonzero except in the special case 0x0, which
 379              * doesn't appear anyway in RSA keys) separated by a
 380              * comma. All hex digits are lowercase in both formats.
 381              */
 382             char *p = otherstr;
 383             char *q = oldstyle;
 384             int i, j;
 385
 386             for (i = 0; i < 2; i++) {
 387                 int ndigits, nwords;
 388                 *p++ = '0';
 389                 *p++ = 'x';
 390                 ndigits = strcspn(q, "/");      /* find / or end of string */
 391                 nwords = ndigits / 4;
 392                 /* now trim ndigits to remove leading zeros */
 393                 while (q[(ndigits - 1) ^ 3] == '0' && ndigits > 1)
 394                     ndigits--;
 395                 /* now move digits over to new string */
 396                 for (j = 0; j < ndigits; j++)
 397                     p[ndigits - 1 - j] = q[j ^ 3];
 398                 p += ndigits;
 399                 q += nwords * 4;
 400                 if (*q) {
 401                     q++;               /* eat the slash */
 402                     *p++ = ',';        /* add a comma */
 403                 }
 404                 *p = '\0';             /* terminate the string */
 405             }
 406
 407             /*
 408              * Now _if_ this key matches, we'll enter it in the new
 409              * format. If not, we'll assume something odd went
 410              * wrong, and hyper-cautiously do nothing.
 411              */
 412             if (!strcmp(otherstr, key))
 413                 RegSetValueEx(rkey, regname, 0, REG_SZ, otherstr,
 414                               strlen(otherstr) + 1);
 415         }
 416     }
 417
 418     RegCloseKey(rkey);
 419
 420     compare = strcmp(otherstr, key);
 421
 422     sfree(otherstr);
 423     sfree(regname);
 424
 425     if (ret == ERROR_MORE_DATA ||
 426         (ret == ERROR_SUCCESS && type == REG_SZ && compare))
 427         return 2;                      /* key is different in registry */
 428     else if (ret != ERROR_SUCCESS || type != REG_SZ)
 429         return 1;                      /* key does not exist in registry */
 430     else
 431         return 0;                      /* key matched OK in registry */
 432 }
 433
 434 void store_host_key(const char *hostname, int port,
 435                     const char *keytype, const char *key)
 436 {
 437     char *regname;
 438     HKEY rkey;
 439
 440     regname = snewn(3 * (strlen(hostname) + strlen(keytype)) + 15, char);
 441
 442     hostkey_regname(regname, hostname, port, keytype);
 443
 444     if (RegCreateKey(HKEY_CURRENT_USER, PUTTY_REG_POS "\\SshHostKeys",
 445                      &rkey) == ERROR_SUCCESS) {
 446         RegSetValueEx(rkey, regname, 0, REG_SZ, key, strlen(key) + 1);
 447         RegCloseKey(rkey);
 448     } /* else key does not exist in registry */
 449
 450     sfree(regname);
 451 }
 452
 453 /*
 454  * Open (or delete) the random seed file.
 455  */
 456 enum { DEL, OPEN_R, OPEN_W };
 457 static int try_random_seed(char const *path, int action, HANDLE *ret)
 458 {
 459     if (action == DEL) {
 460         remove(path);
 461         *ret = INVALID_HANDLE_VALUE;
 462         return FALSE;                  /* so we'll do the next ones too */
 463     }
 464
 465     *ret = CreateFile(path,
 466                       action == OPEN_W ? GENERIC_WRITE : GENERIC_READ,
 467                       action == OPEN_W ? 0 : (FILE_SHARE_READ |
 468                                               FILE_SHARE_WRITE),
 469                       NULL,
 470                       action == OPEN_W ? CREATE_ALWAYS : OPEN_EXISTING,
 471                       action == OPEN_W ? FILE_ATTRIBUTE_NORMAL : 0,
 472                       NULL);
 473
 474     return (*ret != INVALID_HANDLE_VALUE);
 475 }
 476
 477 static HANDLE access_random_seed(int action)
 478 {
 479     HKEY rkey;
 480     DWORD type, size;
 481     HANDLE rethandle;
 482     char seedpath[2 * MAX_PATH + 10] = "\0";
 483
 484     /*
 485      * Iterate over a selection of possible random seed paths until
 486      * we find one that works.
 487      *
 488      * We do this iteration separately for reading and writing,
 489      * meaning that we will automatically migrate random seed files
 490      * if a better location becomes available (by reading from the
 491      * best location in which we actually find one, and then
 492      * writing to the best location in which we can _create_ one).
 493      */
 494
 495     /*
 496      * First, try the location specified by the user in the
 497      * Registry, if any.
 498      */
 499     size = sizeof(seedpath);
 500     if (RegOpenKey(HKEY_CURRENT_USER, PUTTY_REG_POS, &rkey) ==
 501         ERROR_SUCCESS) {
 502         int ret = RegQueryValueEx(rkey, "RandSeedFile",
 503                                   0, &type, seedpath, &size);
 504         if (ret != ERROR_SUCCESS || type != REG_SZ)
 505             seedpath[0] = '\0';
 506         RegCloseKey(rkey);
 507
 508         if (*seedpath && try_random_seed(seedpath, action, &rethandle))
 509             return rethandle;
 510     }
 511
 512     /*
 513      * Next, try the user's local Application Data directory,
 514      * followed by their non-local one. This is found using the
 515      * SHGetFolderPath function, which won't be present on all
 516      * versions of Windows.
 517      */
 518     if (!tried_shgetfolderpath) {
 519         /* This is likely only to bear fruit on systems with IE5+
 520          * installed, or WinMe/2K+. There is some faffing with
 521          * SHFOLDER.DLL we could do to try to find an equivalent
 522          * on older versions of Windows if we cared enough.
 523          * However, the invocation below requires IE5+ anyway,
 524          * so stuff that. */
 525         shell32_module = load_system32_dll("shell32.dll");
 526         GET_WINDOWS_FUNCTION(shell32_module, SHGetFolderPathA);
 527         tried_shgetfolderpath = TRUE;
 528     }
 529     if (p_SHGetFolderPathA) {
 530         if (SUCCEEDED(p_SHGetFolderPathA(NULL, CSIDL_LOCAL_APPDATA,
 531                                          NULL, SHGFP_TYPE_CURRENT, seedpath))) {
 532             strcat(seedpath, "\\PUTTY.RND");
 533             if (try_random_seed(seedpath, action, &rethandle))
 534                 return rethandle;
 535         }
 536
 537         if (SUCCEEDED(p_SHGetFolderPathA(NULL, CSIDL_APPDATA,
 538                                          NULL, SHGFP_TYPE_CURRENT, seedpath))) {
 539             strcat(seedpath, "\\PUTTY.RND");
 540             if (try_random_seed(seedpath, action, &rethandle))
 541                 return rethandle;
 542         }
 543     }
 544
 545     /*
 546      * Failing that, try %HOMEDRIVE%%HOMEPATH% as a guess at the
 547      * user's home directory.
 548      */
 549     {
 550         int len, ret;
 551
 552         len =
 553             GetEnvironmentVariable("HOMEDRIVE", seedpath,
 554                                    sizeof(seedpath));
 555         ret =
 556             GetEnvironmentVariable("HOMEPATH", seedpath + len,
 557                                    sizeof(seedpath) - len);
 558         if (ret != 0) {
 559             strcat(seedpath, "\\PUTTY.RND");
 560             if (try_random_seed(seedpath, action, &rethandle))
 561                 return rethandle;
 562         }
 563     }
 564
 565     /*
 566      * And finally, fall back to C:\WINDOWS.
 567      */
 568     GetWindowsDirectory(seedpath, sizeof(seedpath));
 569     strcat(seedpath, "\\PUTTY.RND");
 570     if (try_random_seed(seedpath, action, &rethandle))
 571         return rethandle;
 572
 573     /*
 574      * If even that failed, give up.
 575      */
 576     return INVALID_HANDLE_VALUE;
 577 }
 578
 579 void read_random_seed(noise_consumer_t consumer)
 580 {
 581     HANDLE seedf = access_random_seed(OPEN_R);
 582
 583     if (seedf != INVALID_HANDLE_VALUE) {
 584         while (1) {
 585             char buf[1024];
 586             DWORD len;
 587
 588             if (ReadFile(seedf, buf, sizeof(buf), &len, NULL) && len)
 589                 consumer(buf, len);
 590             else
 591                 break;
 592         }
 593         CloseHandle(seedf);
 594     }
 595 }
 596
 597 void write_random_seed(void *data, int len)
 598 {
 599     HANDLE seedf = access_random_seed(OPEN_W);
 600
 601     if (seedf != INVALID_HANDLE_VALUE) {
 602         DWORD lenwritten;
 603
 604         WriteFile(seedf, data, len, &lenwritten, NULL);
 605         CloseHandle(seedf);
 606     }
 607 }
 608
 609 /*
 610  * Internal function supporting the jump list registry code. All the
 611  * functions to add, remove and read the list have substantially
 612  * similar content, so this is a generalisation of all of them which
 613  * transforms the list in the registry by prepending 'add' (if
 614  * non-null), removing 'rem' from what's left (if non-null), and
 615  * returning the resulting concatenated list of strings in 'out' (if
 616  * non-null).
 617  */
 618 static int transform_jumplist_registry
 619     (const char *add, const char *rem, char **out)
 620 {
 621     int ret;
 622     HKEY pjumplist_key, psettings_tmp;
 623     DWORD type;
 624     int value_length;
 625     char *old_value, *new_value;
 626     char *piterator_old, *piterator_new, *piterator_tmp;
 627
 628     ret = RegCreateKeyEx(HKEY_CURRENT_USER, reg_jumplist_key, 0, NULL,
 629                          REG_OPTION_NON_VOLATILE, (KEY_READ | KEY_WRITE), NULL,
 630                          &pjumplist_key, NULL);
 631     if (ret != ERROR_SUCCESS) {
 632         return JUMPLISTREG_ERROR_KEYOPENCREATE_FAILURE;
 633     }
 634
 635     /* Get current list of saved sessions in the registry. */
 636     value_length = 200;
 637     old_value = snewn(value_length, char);
 638     ret = RegQueryValueEx(pjumplist_key, reg_jumplist_value, NULL, &type,
 639                           old_value, &value_length);
 640     /* When the passed buffer is too small, ERROR_MORE_DATA is
 641      * returned and the required size is returned in the length
 642      * argument. */
 643     if (ret == ERROR_MORE_DATA) {
 644         sfree(old_value);
 645         old_value = snewn(value_length, char);
 646         ret = RegQueryValueEx(pjumplist_key, reg_jumplist_value, NULL, &type,
 647                               old_value, &value_length);
 648     }
 649
 650     if (ret == ERROR_FILE_NOT_FOUND) {
 651         /* Value doesn't exist yet. Start from an empty value. */
 652         *old_value = '\0';
 653         *(old_value + 1) = '\0';
 654     } else if (ret != ERROR_SUCCESS) {
 655         /* Some non-recoverable error occurred. */
 656         sfree(old_value);
 657         RegCloseKey(pjumplist_key);
 658         return JUMPLISTREG_ERROR_VALUEREAD_FAILURE;
 659     } else if (type != REG_MULTI_SZ) {
 660         /* The value present in the registry has the wrong type: we
 661          * try to delete it and start from an empty value. */
 662         ret = RegDeleteValue(pjumplist_key, reg_jumplist_value);
 663         if (ret != ERROR_SUCCESS) {
 664             sfree(old_value);
 665             RegCloseKey(pjumplist_key);
 666             return JUMPLISTREG_ERROR_VALUEREAD_FAILURE;
 667         }
 668
 669         *old_value = '\0';
 670         *(old_value + 1) = '\0';
 671     }
 672
 673     /* Check validity of registry data: REG_MULTI_SZ value must end
 674      * with \0\0. */
 675     piterator_tmp = old_value;
 676     while (((piterator_tmp - old_value) < (value_length - 1)) &&
 677            !(*piterator_tmp == '\0' && *(piterator_tmp+1) == '\0')) {
 678         ++piterator_tmp;
 679     }
 680
 681     if ((piterator_tmp - old_value) >= (value_length-1)) {
 682         /* Invalid value. Start from an empty value. */
 683         *old_value = '\0';
 684         *(old_value + 1) = '\0';
 685     }
 686
 687     /*
 688      * Modify the list, if we're modifying.
 689      */
 690     if (add || rem) {
 691         /* Walk through the existing list and construct the new list of
 692          * saved sessions. */
 693         new_value = snewn(value_length + (add ? strlen(add) + 1 : 0), char);
 694         piterator_new = new_value;
 695         piterator_old = old_value;
 696
 697         /* First add the new item to the beginning of the list. */
 698         if (add) {
 699             strcpy(piterator_new, add);
 700             piterator_new += strlen(piterator_new) + 1;
 701         }
 702         /* Now add the existing list, taking care to leave out the removed
 703          * item, if it was already in the existing list. */
 704         while (*piterator_old != '\0') {
 705             if (!rem || strcmp(piterator_old, rem) != 0) {
 706                 /* Check if this is a valid session, otherwise don't add. */
 707                 psettings_tmp = open_settings_r(piterator_old);
 708                 if (psettings_tmp != NULL) {
 709                     close_settings_r(psettings_tmp);
 710                     strcpy(piterator_new, piterator_old);
 711                     piterator_new += strlen(piterator_new) + 1;
 712                 }
 713             }
 714             piterator_old += strlen(piterator_old) + 1;
 715         }
 716         *piterator_new = '\0';
 717         ++piterator_new;
 718
 719         /* Save the new list to the registry. */
 720         ret = RegSetValueEx(pjumplist_key, reg_jumplist_value, 0, REG_MULTI_SZ,
 721                             new_value, piterator_new - new_value);
 722
 723         sfree(old_value);
 724         old_value = new_value;
 725     } else
 726         ret = ERROR_SUCCESS;
 727
 728     /*
 729      * Either return or free the result.
 730      */
 731     if (out)
 732         *out = old_value;
 733     else
 734         sfree(old_value);
 735
 736     /* Clean up and return. */
 737     RegCloseKey(pjumplist_key);
 738
 739     if (ret != ERROR_SUCCESS) {
 740         return JUMPLISTREG_ERROR_VALUEWRITE_FAILURE;
 741     } else {
 742         return JUMPLISTREG_OK;
 743     }
 744 }
 745
 746 /* Adds a new entry to the jumplist entries in the registry. */
 747 int add_to_jumplist_registry(const char *item)
 748 {
 749     return transform_jumplist_registry(item, item, NULL);
 750 }
 751
 752 /* Removes an item from the jumplist entries in the registry. */
 753 int remove_from_jumplist_registry(const char *item)
 754 {
 755     return transform_jumplist_registry(NULL, item, NULL);
 756 }
 757
 758 /* Returns the jumplist entries from the registry. Caller must free
 759  * the returned pointer. */
 760 char *get_jumplist_registry_entries (void)
 761 {
 762     char *list_value;
 763
 764     if (transform_jumplist_registry(NULL,NULL,&list_value) != ERROR_SUCCESS) {
 765         list_value = snewn(2, char);
 766         *list_value = '\0';
 767         *(list_value + 1) = '\0';
 768     }
 769     return list_value;
 770 }
 771
 772 /*
 773  * Recursively delete a registry key and everything under it.
 774  */
 775 static void registry_recursive_remove(HKEY key)
 776 {
 777     DWORD i;
 778     char name[MAX_PATH + 1];
 779     HKEY subkey;
 780
 781     i = 0;
 782     while (RegEnumKey(key, i, name, sizeof(name)) == ERROR_SUCCESS) {
 783         if (RegOpenKey(key, name, &subkey) == ERROR_SUCCESS) {
 784             registry_recursive_remove(subkey);
 785             RegCloseKey(subkey);
 786         }
 787         RegDeleteKey(key, name);
 788     }
 789 }
 790
 791 void cleanup_all(void)
 792 {
 793     HKEY key;
 794     int ret;
 795     char name[MAX_PATH + 1];
 796
 797     /* ------------------------------------------------------------
 798      * Wipe out the random seed file, in all of its possible
 799      * locations.
 800      */
 801     access_random_seed(DEL);
 802
 803     /* ------------------------------------------------------------
 804      * Ask Windows to delete any jump list information associated
 805      * with this installation of PuTTY.
 806      */
 807     clear_jumplist();
 808
 809     /* ------------------------------------------------------------
 810      * Destroy all registry information associated with PuTTY.
 811      */
 812
 813     /*
 814      * Open the main PuTTY registry key and remove everything in it.
 815      */
 816     if (RegOpenKey(HKEY_CURRENT_USER, PUTTY_REG_POS, &key) ==
 817         ERROR_SUCCESS) {
 818         registry_recursive_remove(key);
 819         RegCloseKey(key);
 820     }
 821     /*
 822      * Now open the parent key and remove the PuTTY main key. Once
 823      * we've done that, see if the parent key has any other
 824      * children.
 825      */
 826     if (RegOpenKey(HKEY_CURRENT_USER, PUTTY_REG_PARENT,
 827                    &key) == ERROR_SUCCESS) {
 828         RegDeleteKey(key, PUTTY_REG_PARENT_CHILD);
 829         ret = RegEnumKey(key, 0, name, sizeof(name));
 830         RegCloseKey(key);
 831         /*
 832          * If the parent key had no other children, we must delete
 833          * it in its turn. That means opening the _grandparent_
 834          * key.
 835          */
 836         if (ret != ERROR_SUCCESS) {
 837             if (RegOpenKey(HKEY_CURRENT_USER, PUTTY_REG_GPARENT,
 838                            &key) == ERROR_SUCCESS) {
 839                 RegDeleteKey(key, PUTTY_REG_GPARENT_CHILD);
 840                 RegCloseKey(key);
 841             }
 842         }
 843     }
 844     /*
 845      * Now we're done.
 846      */
 847 }