puttygen.c

   1 /*
   2  * PuTTY key generation front end.
   3  */
   4
   5 #include <windows.h>
   6 #include <commctrl.h>
   7 #include <time.h>
   8 #include <stdio.h>
   9 #include <stdlib.h>
  10
  11 #define PUTTY_DO_GLOBALS
  12
  13 #include "putty.h"
  14 #include "ssh.h"
  15 #include "winstuff.h"
  16
  17 #define WM_DONEKEY (WM_XUSER + 1)
  18
  19 #define DEFAULT_KEYSIZE 1024
  20
  21 /* ----------------------------------------------------------------------
  22  * Progress report code. This is really horrible :-)
  23  */
  24 #define PHASE1TOTAL 0x10000
  25 #define PHASE2TOTAL 0x10000
  26 #define PHASE3TOTAL 0x04000
  27 #define PHASE1START 0
  28 #define PHASE2START (PHASE1TOTAL)
  29 #define PHASE3START (PHASE1TOTAL + PHASE2TOTAL)
  30 #define TOTALTOTAL  (PHASE1TOTAL + PHASE2TOTAL + PHASE3TOTAL)
  31 #define PROGRESSBIGRANGE 65535
  32 #define DIVISOR     ((TOTALTOTAL + PROGRESSBIGRANGE - 1) / PROGRESSBIGRANGE)
  33 #define PROGRESSRANGE (TOTALTOTAL / DIVISOR)
  34 struct progress {
  35     unsigned phase1param, phase1current, phase1n;
  36     unsigned phase2param, phase2current, phase2n;
  37     unsigned phase3mult;
  38     HWND progbar;
  39 };
  40
  41 static void progress_update(void *param, int phase, int iprogress) {
  42     struct progress *p = (struct progress *)param;
  43     unsigned progress = iprogress;
  44     int position;
  45
  46     switch (phase) {
  47       case -1:
  48         p->phase1param = 0x10000 + progress;
  49         p->phase1current = 0x10000; p->phase1n = 0;
  50         return;
  51       case -2:
  52         p->phase2param = 0x10000 + progress;
  53         p->phase2current = 0x10000; p->phase2n = 0;
  54         return;
  55       case -3:
  56         p->phase3mult = PHASE3TOTAL / progress;
  57         return;
  58       case 1:
  59         while (p->phase1n < progress) {
  60             p->phase1n++;
  61             p->phase1current *= p->phase1param;
  62             p->phase1current /= 0x10000;
  63         }
  64         position = PHASE1START + 0x10000 - p->phase1current;
  65         break;
  66       case 2:
  67         while (p->phase2n < progress) {
  68             p->phase2n++;
  69             p->phase2current *= p->phase2param;
  70             p->phase2current /= 0x10000;
  71         }
  72         position = PHASE2START + 0x10000 - p->phase2current;
  73         break;
  74       case 3:
  75         position = PHASE3START + progress * p->phase3mult;
  76         break;
  77     }
  78
  79     SendMessage(p->progbar, PBM_SETPOS, position / DIVISOR, 0);
  80 }
  81
  82 extern char ver[];
  83
  84 #define PASSPHRASE_MAXLEN 512
  85
  86 struct PassphraseProcStruct {
  87     char *passphrase;
  88     char *comment;
  89 };
  90
  91 /*
  92  * Dialog-box function for the passphrase box.
  93  */
  94 static int CALLBACK PassphraseProc(HWND hwnd, UINT msg,
  95                                    WPARAM wParam, LPARAM lParam) {
  96     static char *passphrase = NULL;
  97     struct PassphraseProcStruct *p;
  98
  99     switch (msg) {
 100       case WM_INITDIALOG:
 101         SetForegroundWindow(hwnd);
 102         SetWindowPos (hwnd, HWND_TOP, 0, 0, 0, 0,
 103                       SWP_NOMOVE | SWP_NOSIZE | SWP_SHOWWINDOW);
 104
 105         /*
 106          * Centre the window.
 107          */
 108         {                              /* centre the window */
 109             RECT rs, rd;
 110             HWND hw;
 111
 112             hw = GetDesktopWindow();
 113             if (GetWindowRect (hw, &rs) && GetWindowRect (hwnd, &rd))
 114                 MoveWindow (hwnd, (rs.right + rs.left + rd.left - rd.right)/2,
 115                             (rs.bottom + rs.top + rd.top - rd.bottom)/2,
 116                             rd.right-rd.left, rd.bottom-rd.top, TRUE);
 117         }
 118
 119         p = (struct PassphraseProcStruct *)lParam;
 120         passphrase = p->passphrase;
 121         if (p->comment)
 122             SetDlgItemText(hwnd, 101, p->comment);
 123         *passphrase = 0;
 124         SetDlgItemText(hwnd, 102, passphrase);
 125         return 0;
 126       case WM_COMMAND:
 127         switch (LOWORD(wParam)) {
 128           case IDOK:
 129             if (*passphrase)
 130                 EndDialog (hwnd, 1);
 131             else
 132                 MessageBeep (0);
 133             return 0;
 134           case IDCANCEL:
 135             EndDialog (hwnd, 0);
 136             return 0;
 137           case 102:                    /* edit box */
 138             if ((HIWORD(wParam) == EN_CHANGE) && passphrase) {
 139                 GetDlgItemText (hwnd, 102, passphrase, PASSPHRASE_MAXLEN-1);
 140                 passphrase[PASSPHRASE_MAXLEN-1] = '\0';
 141             }
 142             return 0;
 143         }
 144         return 0;
 145       case WM_CLOSE:
 146         EndDialog (hwnd, 0);
 147         return 0;
 148     }
 149     return 0;
 150 }
 151
 152 /*
 153  * Prompt for a key file. Assumes the filename buffer is of size
 154  * FILENAME_MAX.
 155  */
 156 static int prompt_keyfile(HWND hwnd, char *dlgtitle,
 157                           char *filename, int save) {
 158     OPENFILENAME of;
 159     memset(&of, 0, sizeof(of));
 160 #ifdef OPENFILENAME_SIZE_VERSION_400
 161     of.lStructSize = OPENFILENAME_SIZE_VERSION_400;
 162 #else
 163     of.lStructSize = sizeof(of);
 164 #endif
 165     of.hwndOwner = hwnd;
 166     of.lpstrFilter = "All Files\0*\0\0\0";
 167     of.lpstrCustomFilter = NULL;
 168     of.nFilterIndex = 1;
 169     of.lpstrFile = filename; *filename = '\0';
 170     of.nMaxFile = FILENAME_MAX;
 171     of.lpstrFileTitle = NULL;
 172     of.lpstrInitialDir = NULL;
 173     of.lpstrTitle = dlgtitle;
 174     of.Flags = 0;
 175     if (save)
 176         return GetSaveFileName(&of);
 177     else
 178         return GetOpenFileName(&of);
 179 }
 180
 181 /*
 182  * This function is needed to link with the DES code. We need not
 183  * have it do anything at all.
 184  */
 185 void logevent(char *msg) {
 186 }
 187
 188 /*
 189  * Dialog-box function for the Licence box.
 190  */
 191 static int CALLBACK LicenceProc (HWND hwnd, UINT msg,
 192                                  WPARAM wParam, LPARAM lParam) {
 193     switch (msg) {
 194       case WM_INITDIALOG:
 195         /*
 196          * Centre the window.
 197          */
 198         {                              /* centre the window */
 199             RECT rs, rd;
 200             HWND hw;
 201
 202             hw = GetDesktopWindow();
 203             if (GetWindowRect (hw, &rs) && GetWindowRect (hwnd, &rd))
 204                 MoveWindow (hwnd, (rs.right + rs.left + rd.left - rd.right)/2,
 205                             (rs.bottom + rs.top + rd.top - rd.bottom)/2,
 206                             rd.right-rd.left, rd.bottom-rd.top, TRUE);
 207         }
 208
 209         return 1;
 210       case WM_COMMAND:
 211         switch (LOWORD(wParam)) {
 212           case IDOK:
 213             EndDialog(hwnd, 1);
 214             return 0;
 215         }
 216         return 0;
 217       case WM_CLOSE:
 218         EndDialog(hwnd, 1);
 219         return 0;
 220     }
 221     return 0;
 222 }
 223
 224 /*
 225  * Dialog-box function for the About box.
 226  */
 227 static int CALLBACK AboutProc (HWND hwnd, UINT msg,
 228                                WPARAM wParam, LPARAM lParam) {
 229     switch (msg) {
 230       case WM_INITDIALOG:
 231         /*
 232          * Centre the window.
 233          */
 234         {                              /* centre the window */
 235             RECT rs, rd;
 236             HWND hw;
 237
 238             hw = GetDesktopWindow();
 239             if (GetWindowRect (hw, &rs) && GetWindowRect (hwnd, &rd))
 240                 MoveWindow (hwnd, (rs.right + rs.left + rd.left - rd.right)/2,
 241                             (rs.bottom + rs.top + rd.top - rd.bottom)/2,
 242                             rd.right-rd.left, rd.bottom-rd.top, TRUE);
 243         }
 244
 245         SetDlgItemText (hwnd, 100, ver);
 246         return 1;
 247       case WM_COMMAND:
 248         switch (LOWORD(wParam)) {
 249           case IDOK:
 250             EndDialog(hwnd, 1);
 251             return 0;
 252           case 101:
 253             EnableWindow(hwnd, 0);
 254             DialogBox (hinst, MAKEINTRESOURCE(214), NULL, LicenceProc);
 255             EnableWindow(hwnd, 1);
 256             SetActiveWindow(hwnd);
 257             return 0;
 258         }
 259         return 0;
 260       case WM_CLOSE:
 261         EndDialog(hwnd, 1);
 262         return 0;
 263     }
 264     return 0;
 265 }
 266
 267 /*
 268  * Thread to generate a key.
 269  */
 270 struct rsa_key_thread_params {
 271     HWND progressbar;                  /* notify this with progress */
 272     HWND dialog;                       /* notify this on completion */
 273     int keysize;                       /* bits in key */
 274     struct RSAKey *key;
 275 };
 276 static DWORD WINAPI generate_rsa_key_thread(void *param) {
 277     struct rsa_key_thread_params *params =
 278         (struct rsa_key_thread_params *)param;
 279     struct progress prog;
 280     prog.progbar = params->progressbar;
 281
 282     rsa_generate(params->key, params->keysize, progress_update, &prog);
 283
 284     PostMessage(params->dialog, WM_DONEKEY, 0, 0);
 285
 286     sfree(params);
 287     return 0;
 288 }
 289
 290 struct MainDlgState {
 291     int collecting_entropy;
 292     int generation_thread_exists;
 293     int key_exists;
 294     int entropy_got, entropy_required, entropy_size;
 295     int keysize;
 296     int ssh2;
 297     char **commentptr;                 /* points to key.comment or ssh2key.comment */
 298     struct ssh2_userkey ssh2key;
 299     unsigned *entropy;
 300     struct RSAKey key;
 301 };
 302
 303 static void hidemany(HWND hwnd, const int *ids, int hideit) {
 304     while (*ids) {
 305         ShowWindow(GetDlgItem(hwnd, *ids++), (hideit ? SW_HIDE : SW_SHOW));
 306     }
 307 }
 308
 309 static void setupbigedit1(HWND hwnd, int id, struct RSAKey *key) {
 310     char *buffer;
 311     char *dec1, *dec2;
 312
 313     dec1 = bignum_decimal(key->exponent);
 314     dec2 = bignum_decimal(key->modulus);
 315     buffer = smalloc(strlen(dec1)+strlen(dec2)+
 316                      strlen(key->comment)+30);
 317     sprintf(buffer, "%d %s %s %s",
 318             bignum_bitcount(key->modulus),
 319             dec1, dec2, key->comment);
 320     SetDlgItemText(hwnd, id, buffer);
 321     sfree(dec1);
 322     sfree(dec2);
 323     sfree(buffer);
 324 }
 325
 326 static void setupbigedit2(HWND hwnd, int id, struct ssh2_userkey *key) {
 327     unsigned char *pub_blob;
 328     char *buffer, *p;
 329     int pub_len;
 330     int i;
 331
 332     pub_blob = key->alg->public_blob(key->data, &pub_len);
 333     buffer = smalloc(strlen(key->alg->name) + 4*((pub_len+2)/3) +
 334                      strlen(key->comment) + 3);
 335     strcpy(buffer, key->alg->name);
 336     p = buffer + strlen(buffer);
 337     *p++ = ' ';
 338     i = 0;
 339     while (i < pub_len) {
 340         int n = (pub_len-i < 3 ? pub_len-i : 3);
 341         base64_encode_atom(pub_blob+i, n, p);
 342         i += n;
 343         p += 4;
 344     }
 345     *p++ = ' ';
 346     strcpy(p, key->comment);
 347     SetDlgItemText(hwnd, id, buffer);
 348     sfree(pub_blob);
 349     sfree(buffer);
 350 }
 351
 352 /*
 353  * Dialog-box function for the main PuTTYgen dialog box.
 354  */
 355 static int CALLBACK MainDlgProc (HWND hwnd, UINT msg,
 356                                  WPARAM wParam, LPARAM lParam) {
 357     enum {
 358         controlidstart = 100,
 359         IDC_TITLE,
 360         IDC_BOX_KEY,
 361         IDC_NOKEY,
 362         IDC_GENERATING,
 363         IDC_PROGRESS,
 364         IDC_PKSTATIC, IDC_KEYDISPLAY,
 365         IDC_FPSTATIC, IDC_FINGERPRINT,
 366         IDC_COMMENTSTATIC, IDC_COMMENTEDIT,
 367         IDC_PASSPHRASE1STATIC, IDC_PASSPHRASE1EDIT,
 368         IDC_PASSPHRASE2STATIC, IDC_PASSPHRASE2EDIT,
 369         IDC_BOX_ACTIONS,
 370         IDC_GENSTATIC, IDC_GENERATE,
 371         IDC_LOADSTATIC, IDC_LOAD,
 372         IDC_SAVESTATIC, IDC_SAVE,
 373         IDC_BOX_PARAMS,
 374         IDC_TYPESTATIC, IDC_KEYSSH1, IDC_KEYSSH2RSA,
 375         IDC_BITSSTATIC, IDC_BITS,
 376         IDC_ABOUT,
 377     };
 378     static const int nokey_ids[] = { IDC_NOKEY, 0 };
 379     static const int generating_ids[] = { IDC_GENERATING, IDC_PROGRESS, 0 };
 380     static const int gotkey_ids[] = {
 381         IDC_PKSTATIC, IDC_KEYDISPLAY,
 382         IDC_FPSTATIC, IDC_FINGERPRINT,
 383         IDC_COMMENTSTATIC, IDC_COMMENTEDIT,
 384         IDC_PASSPHRASE1STATIC, IDC_PASSPHRASE1EDIT,
 385         IDC_PASSPHRASE2STATIC, IDC_PASSPHRASE2EDIT, 0 };
 386     static const char generating_msg[] =
 387         "Please wait while a key is generated...";
 388     static const char entropy_msg[] =
 389         "Please generate some randomness by moving the mouse over the blank area.";
 390     struct MainDlgState *state;
 391
 392     switch (msg) {
 393       case WM_INITDIALOG:
 394         /*
 395          * Centre the window.
 396          */
 397         {                              /* centre the window */
 398             RECT rs, rd;
 399             HWND hw;
 400
 401             hw = GetDesktopWindow();
 402             if (GetWindowRect (hw, &rs) && GetWindowRect (hwnd, &rd))
 403                 MoveWindow (hwnd, (rs.right + rs.left + rd.left - rd.right)/2,
 404                             (rs.bottom + rs.top + rd.top - rd.bottom)/2,
 405                             rd.right-rd.left, rd.bottom-rd.top, TRUE);
 406         }
 407
 408         state = smalloc(sizeof(*state));
 409         state->generation_thread_exists = FALSE;
 410         state->collecting_entropy = FALSE;
 411         state->entropy = NULL;
 412         state->key_exists = FALSE;
 413         SetWindowLong(hwnd, GWL_USERDATA, (LONG)state);
 414         {
 415             struct ctlpos cp, cp2;
 416
 417             /* Accelerators used: acglops */
 418
 419             ctlposinit(&cp, hwnd, 10, 10, 10);
 420             bartitle(&cp, "Public and private key generation for PuTTY",
 421                     IDC_TITLE);
 422             beginbox(&cp, "Key",
 423                      IDC_BOX_KEY);
 424             cp2 = cp;
 425             statictext(&cp2, "No key.", IDC_NOKEY);
 426             cp2 = cp;
 427             statictext(&cp2, "",
 428                        IDC_GENERATING);
 429             progressbar(&cp2, IDC_PROGRESS);
 430             bigeditctrl(&cp,
 431                         "&Public key for pasting into authorized_keys file:",
 432                         IDC_PKSTATIC, IDC_KEYDISPLAY, 7);
 433             SendDlgItemMessage(hwnd, IDC_KEYDISPLAY, EM_SETREADONLY, 1, 0);
 434             staticedit(&cp, "Key fingerprint:", IDC_FPSTATIC,
 435                        IDC_FINGERPRINT, 75);
 436             SendDlgItemMessage(hwnd, IDC_FINGERPRINT, EM_SETREADONLY, 1, 0);
 437             staticedit(&cp, "Key &comment:", IDC_COMMENTSTATIC,
 438                        IDC_COMMENTEDIT, 75);
 439             staticpassedit(&cp, "Key p&assphrase:", IDC_PASSPHRASE1STATIC,
 440                            IDC_PASSPHRASE1EDIT, 75);
 441             staticpassedit(&cp, "C&onfirm passphrase:", IDC_PASSPHRASE2STATIC,
 442                            IDC_PASSPHRASE2EDIT, 75);
 443             endbox(&cp);
 444             beginbox(&cp, "Actions",
 445                      IDC_BOX_ACTIONS);
 446             staticbtn(&cp, "Generate a public/private key pair",
 447                       IDC_GENSTATIC, "&Generate", IDC_GENERATE);
 448             staticbtn(&cp, "Load an existing private key file",
 449                       IDC_LOADSTATIC, "&Load", IDC_LOAD);
 450             staticbtn(&cp, "Save the generated key to a new file",
 451                       IDC_SAVESTATIC, "&Save", IDC_SAVE);
 452             endbox(&cp);
 453             beginbox(&cp, "Parameters",
 454                      IDC_BOX_PARAMS);
 455             radioline(&cp, "Type of key to generate:", IDC_TYPESTATIC, 2,
 456                           "SSH&1 (RSA)", IDC_KEYSSH1,
 457                           "SSH2 &RSA", IDC_KEYSSH2RSA, NULL);
 458             staticedit(&cp, "Number of &bits in a generated key:",
 459                        IDC_BITSSTATIC, IDC_BITS, 20);
 460             endbox(&cp);
 461         }
 462         CheckRadioButton(hwnd, IDC_KEYSSH1, IDC_KEYSSH2RSA, IDC_KEYSSH1);
 463         SetDlgItemInt(hwnd, IDC_BITS, DEFAULT_KEYSIZE, FALSE);
 464
 465         /*
 466          * Initially, hide the progress bar and the key display,
 467          * and show the no-key display. Also disable the Save
 468          * button, because with no key we obviously can't save
 469          * anything.
 470          */
 471         hidemany(hwnd, nokey_ids, FALSE);
 472         hidemany(hwnd, generating_ids, TRUE);
 473         hidemany(hwnd, gotkey_ids, TRUE);
 474         EnableWindow(GetDlgItem(hwnd, IDC_SAVE), 0);
 475
 476         return 1;
 477       case WM_MOUSEMOVE:
 478         state = (struct MainDlgState *)GetWindowLong(hwnd, GWL_USERDATA);
 479         if (state->collecting_entropy &&
 480             state->entropy &&
 481             state->entropy_got < state->entropy_required) {
 482             state->entropy[state->entropy_got++] = lParam;
 483             state->entropy[state->entropy_got++] = GetMessageTime();
 484             SendDlgItemMessage(hwnd, IDC_PROGRESS, PBM_SETPOS,
 485                                state->entropy_got, 0);
 486             if (state->entropy_got >= state->entropy_required) {
 487                 struct rsa_key_thread_params *params;
 488                 DWORD threadid;
 489
 490                 /*
 491                  * Seed the entropy pool
 492                  */
 493                 random_add_heavynoise(state->entropy, state->entropy_size);
 494                 memset(state->entropy, 0, state->entropy_size);
 495                 sfree(state->entropy);
 496                 state->collecting_entropy = FALSE;
 497
 498                 SetDlgItemText(hwnd, IDC_GENERATING, generating_msg);
 499                 SendDlgItemMessage(hwnd, IDC_PROGRESS, PBM_SETRANGE, 0,
 500                                    MAKELPARAM(0, PROGRESSRANGE));
 501                 SendDlgItemMessage(hwnd, IDC_PROGRESS, PBM_SETPOS, 0, 0);
 502
 503                 params = smalloc(sizeof(*params));
 504                 params->progressbar = GetDlgItem(hwnd, IDC_PROGRESS);
 505                 params->dialog = hwnd;
 506                 params->keysize = state->keysize;
 507                 params->key = &state->key;
 508
 509                 if (!CreateThread(NULL, 0, generate_rsa_key_thread,
 510                                   params, 0, &threadid)) {
 511                     MessageBox(hwnd, "Out of thread resources",
 512                                "Key generation error",
 513                                MB_OK | MB_ICONERROR);
 514                     sfree(params);
 515                 } else {
 516                     state->generation_thread_exists = TRUE;
 517                 }
 518             }
 519         }
 520         break;
 521       case WM_COMMAND:
 522         switch (LOWORD(wParam)) {
 523           case IDC_COMMENTEDIT:
 524             if (HIWORD(wParam) == EN_CHANGE) {
 525                 state = (struct MainDlgState *)
 526                     GetWindowLong(hwnd, GWL_USERDATA);
 527                 if (state->key_exists) {
 528                     HWND editctl = GetDlgItem(hwnd, IDC_COMMENTEDIT);
 529                     int len = GetWindowTextLength(editctl);
 530                     if (*state->commentptr)
 531                         sfree(*state->commentptr);
 532                     *state->commentptr = smalloc(len+1);
 533                     GetWindowText(editctl, *state->commentptr, len+1);
 534                     if (state->ssh2) {
 535                         setupbigedit2(hwnd, IDC_KEYDISPLAY, &state->ssh2key);
 536                     } else {
 537                         setupbigedit1(hwnd, IDC_KEYDISPLAY, &state->key);
 538                     }
 539                 }
 540             }
 541             break;
 542           case IDC_ABOUT:
 543             EnableWindow(hwnd, 0);
 544             DialogBox (hinst, MAKEINTRESOURCE(213), NULL, AboutProc);
 545             EnableWindow(hwnd, 1);
 546             SetActiveWindow(hwnd);
 547             return 0;
 548           case IDC_GENERATE:
 549             state = (struct MainDlgState *)GetWindowLong(hwnd, GWL_USERDATA);
 550             if (!state->generation_thread_exists) {
 551                 BOOL ok;
 552                 state->keysize = GetDlgItemInt(hwnd, IDC_BITS,
 553                                                &ok, FALSE);
 554                 if (!ok) state->keysize = DEFAULT_KEYSIZE;
 555                 /* If we ever introduce a new key type, check it here! */
 556                 state->ssh2 = !IsDlgButtonChecked(hwnd, IDC_KEYSSH1);
 557                 if (state->keysize < 256) {
 558                     int ret = MessageBox(hwnd,
 559                                          "PuTTYgen will not generate a key"
 560                                          " smaller than 256 bits.\n"
 561                                          "Key length reset to 256. Continue?",
 562                                          "PuTTYgen Warning",
 563                                          MB_ICONWARNING | MB_OKCANCEL);
 564                     if (ret != IDOK)
 565                         break;
 566                     state->keysize = 256;
 567                     SetDlgItemInt(hwnd, IDC_BITS, 256, FALSE);
 568                 }
 569                 hidemany(hwnd, nokey_ids, TRUE);
 570                 hidemany(hwnd, generating_ids, FALSE);
 571                 hidemany(hwnd, gotkey_ids, TRUE);
 572                 EnableWindow(GetDlgItem(hwnd, IDC_GENERATE), 0);
 573                 EnableWindow(GetDlgItem(hwnd, IDC_LOAD), 0);
 574                 EnableWindow(GetDlgItem(hwnd, IDC_SAVE), 0);
 575                 state->key_exists = FALSE;
 576                 SetDlgItemText(hwnd, IDC_GENERATING, entropy_msg);
 577                 state->collecting_entropy = TRUE;
 578
 579                 /*
 580                  * My brief statistical tests on mouse movements
 581                  * suggest that there are about 2.5 bits of
 582                  * randomness in the x position, 2.5 in the y
 583                  * position, and 1.7 in the message time, making
 584                  * 5.7 bits of unpredictability per mouse movement.
 585                  * However, other people have told me it's far less
 586                  * than that, so I'm going to be stupidly cautious
 587                  * and knock that down to a nice round 2. With this
 588                  * method, we require two words per mouse movement,
 589                  * so with 2 bits per mouse movement we expect 2
 590                  * bits every 2 words.
 591                  */
 592                 state->entropy_required = (state->keysize/2) * 2;
 593                 state->entropy_got = 0;
 594                 state->entropy_size = (state->entropy_required *
 595                                        sizeof(*state->entropy));
 596                 state->entropy = smalloc(state->entropy_size);
 597
 598                 SendDlgItemMessage(hwnd, IDC_PROGRESS, PBM_SETRANGE, 0,
 599                                    MAKELPARAM(0, state->entropy_required));
 600                 SendDlgItemMessage(hwnd, IDC_PROGRESS, PBM_SETPOS, 0, 0);
 601             }
 602             break;
 603           case IDC_SAVE:
 604             state = (struct MainDlgState *)GetWindowLong(hwnd, GWL_USERDATA);
 605             if (state->key_exists) {
 606                 char filename[FILENAME_MAX];
 607                 char passphrase[PASSPHRASE_MAXLEN];
 608                 char passphrase2[PASSPHRASE_MAXLEN];
 609                 GetDlgItemText(hwnd, IDC_PASSPHRASE1EDIT,
 610                                passphrase, sizeof(passphrase));
 611                 GetDlgItemText(hwnd, IDC_PASSPHRASE2EDIT,
 612                                passphrase2, sizeof(passphrase2));
 613                 if (strcmp(passphrase, passphrase2)) {
 614                     MessageBox(hwnd,
 615                                "The two passphrases given do not match.",
 616                                "PuTTYgen Error",
 617                                MB_OK | MB_ICONERROR);
 618                     break;
 619                 }
 620                 if (!*passphrase) {
 621                     int ret;
 622                     ret = MessageBox(hwnd,
 623                                      "Are you sure you want to save this key\n"
 624                                      "without a passphrase to protect it?",
 625                                      "PuTTYgen Warning",
 626                                      MB_YESNO | MB_ICONWARNING);
 627                     if (ret != IDYES)
 628                         break;
 629                 }
 630                 if (prompt_keyfile(hwnd, "Save private key as:",
 631                                    filename, 1)) {
 632                     int ret;
 633                     FILE *fp = fopen(filename, "r");
 634                     if (fp) {
 635                         char buffer[FILENAME_MAX+80];
 636                         fclose(fp);
 637                         sprintf(buffer, "Overwrite existing file\n%.*s?",
 638                                 FILENAME_MAX, filename);
 639                         ret = MessageBox(hwnd, buffer, "PuTTYgen Warning",
 640                                          MB_YESNO | MB_ICONWARNING);
 641                         if (ret != IDYES)
 642                             break;
 643                     }
 644                     if (state->ssh2) {
 645                         ret = ssh2_save_userkey(filename, &state->ssh2key,
 646                                                 *passphrase ? passphrase : NULL);
 647                     } else {
 648                         ret = saversakey(filename, &state->key,
 649                                          *passphrase ? passphrase : NULL);
 650                     }
 651                     if (ret <= 0) {
 652                         MessageBox(hwnd, "Unable to save key file",
 653                                    "PuTTYgen Error",
 654                                    MB_OK | MB_ICONERROR);
 655                     }
 656                 }
 657             }
 658             break;
 659           case IDC_LOAD:
 660             state = (struct MainDlgState *)GetWindowLong(hwnd, GWL_USERDATA);
 661             if (!state->generation_thread_exists) {
 662                 char filename[FILENAME_MAX];
 663                 if (prompt_keyfile(hwnd, "Load private key:",
 664                                    filename, 0)) {
 665                     char passphrase[PASSPHRASE_MAXLEN];
 666                     int needs_pass;
 667                     int ver;
 668                     int ret;
 669                     char *comment;
 670                     struct PassphraseProcStruct pps;
 671                     struct RSAKey newkey1;
 672                     struct ssh2_userkey *newkey2;
 673
 674                     ver = keyfile_version(filename);
 675                     if (ver == 0) {
 676                         MessageBox(NULL, "Couldn't load private key.",
 677                                    "PuTTYgen Error", MB_OK | MB_ICONERROR);
 678                         break;
 679                     }
 680
 681                     comment = NULL;
 682                     if (ver == 1)
 683                         needs_pass = rsakey_encrypted(filename, &comment);
 684                     else
 685                         needs_pass = ssh2_userkey_encrypted(filename, &comment);
 686                     pps.passphrase = passphrase;
 687                     pps.comment = comment;
 688                     do {
 689                         if (needs_pass) {
 690                             int dlgret;
 691                             dlgret = DialogBoxParam(hinst,
 692                                                     MAKEINTRESOURCE(210),
 693                                                     NULL, PassphraseProc,
 694                                                     (LPARAM)&pps);
 695                             if (!dlgret) {
 696                                 ret = -2;
 697                                 break;
 698                             }
 699                         } else
 700                             *passphrase = '\0';
 701                         if (ver == 1)
 702                             ret = loadrsakey(filename, &newkey1, passphrase);
 703                         else {
 704                             newkey2 = ssh2_load_userkey(filename, passphrase);
 705                             if (newkey2 == SSH2_WRONG_PASSPHRASE)
 706                                 ret = -1;
 707                             else if (!newkey2)
 708                                 ret = 0;
 709                             else
 710                                 ret = 1;
 711                         }
 712                     } while (ret == -1);
 713                     if (comment) sfree(comment);
 714                     if (ret == 0) {
 715                         MessageBox(NULL, "Couldn't load private key.",
 716                                    "PuTTYgen Error", MB_OK | MB_ICONERROR);
 717                     } else if (ret == 1) {
 718                         EnableWindow(GetDlgItem(hwnd, IDC_GENERATE), 1);
 719                         EnableWindow(GetDlgItem(hwnd, IDC_LOAD), 1);
 720                         EnableWindow(GetDlgItem(hwnd, IDC_SAVE), 1);
 721                         /*
 722                          * Now update the key controls with all the
 723                          * key data.
 724                          */
 725                         {
 726                             SetDlgItemText(hwnd, IDC_PASSPHRASE1EDIT,
 727                                            passphrase);
 728                             SetDlgItemText(hwnd, IDC_PASSPHRASE2EDIT,
 729                                            passphrase);
 730                             if (ver == 1) {
 731                                 char buf[128];
 732                                 char *savecomment;
 733
 734                                 state->ssh2 = FALSE;
 735                                 state->commentptr = &state->key.comment;
 736                                 state->key = newkey1;
 737
 738                                 /*
 739                                  * Set the key fingerprint.
 740                                  */
 741                                 savecomment = state->key.comment;
 742                                 state->key.comment = NULL;
 743                                 rsa_fingerprint(buf, sizeof(buf), &state->key);
 744                                 state->key.comment = savecomment;
 745
 746                                 SetDlgItemText(hwnd, IDC_FINGERPRINT, buf);
 747                                 /*
 748                                  * Construct a decimal representation
 749                                  * of the key, for pasting into
 750                                  * .ssh/authorized_keys on a Unix box.
 751                                  */
 752                                 setupbigedit1(hwnd, IDC_KEYDISPLAY, &state->key);
 753                             } else {
 754                                 char *fp;
 755                                 char *savecomment;
 756
 757                                 state->ssh2 = TRUE;
 758                                 state->commentptr = &state->ssh2key.comment;
 759                                 state->ssh2key = *newkey2;   /* structure copy */
 760                                 sfree(newkey2);
 761
 762                                 savecomment = state->ssh2key.comment;
 763                                 state->ssh2key.comment = NULL;
 764                                 fp = state->
 765                                     ssh2key.alg->fingerprint(state->ssh2key.data);
 766                                 state->ssh2key.comment = savecomment;
 767
 768                                 SetDlgItemText(hwnd, IDC_FINGERPRINT, fp);
 769                                 sfree(fp);
 770
 771                                 setupbigedit2(hwnd, IDC_KEYDISPLAY, &state->ssh2key);
 772                             }
 773                             SetDlgItemText(hwnd, IDC_COMMENTEDIT,
 774                                            *state->commentptr);
 775                         }
 776                         /*
 777                          * Finally, hide the progress bar and show
 778                          * the key data.
 779                          */
 780                         hidemany(hwnd, nokey_ids, TRUE);
 781                         hidemany(hwnd, generating_ids, TRUE);
 782                         hidemany(hwnd, gotkey_ids, FALSE);
 783                         state->key_exists = TRUE;
 784                     }
 785                 }
 786             }
 787             break;
 788         }
 789         return 0;
 790       case WM_DONEKEY:
 791         state = (struct MainDlgState *)GetWindowLong(hwnd, GWL_USERDATA);
 792         state->generation_thread_exists = FALSE;
 793         state->key_exists = TRUE;
 794         SendDlgItemMessage(hwnd, IDC_PROGRESS, PBM_SETPOS, PROGRESSRANGE, 0);
 795         EnableWindow(GetDlgItem(hwnd, IDC_GENERATE), 1);
 796         EnableWindow(GetDlgItem(hwnd, IDC_LOAD), 1);
 797         EnableWindow(GetDlgItem(hwnd, IDC_SAVE), 1);
 798         if (state->ssh2) {
 799             state->ssh2key.data = &state->key;
 800             state->ssh2key.alg = &ssh_rsa;
 801             state->commentptr = &state->ssh2key.comment;
 802         } else {
 803             state->commentptr = &state->key.comment;
 804         }
 805         /*
 806          * Invent a comment for the key. We'll do this by including
 807          * the date in it. This will be so horrifyingly ugly that
 808          * the user will immediately want to change it, which is
 809          * what we want :-)
 810          */
 811         *state->commentptr = smalloc(30);
 812         {
 813             time_t t;
 814             struct tm *tm;
 815             time(&t);
 816             tm = localtime(&t);
 817             strftime(*state->commentptr, 30, "rsa-key-%Y%m%d", tm);
 818         }
 819
 820         /*
 821          * Now update the key controls with all the key data.
 822          */
 823         {
 824             char *savecomment;
 825             /*
 826              * Blank passphrase, initially. This isn't dangerous,
 827              * because we will warn (Are You Sure?) before allowing
 828              * the user to save an unprotected private key.
 829              */
 830             SetDlgItemText(hwnd, IDC_PASSPHRASE1EDIT, "");
 831             SetDlgItemText(hwnd, IDC_PASSPHRASE2EDIT, "");
 832             /*
 833              * Set the comment.
 834              */
 835             SetDlgItemText(hwnd, IDC_COMMENTEDIT, *state->commentptr);
 836             /*
 837              * Set the key fingerprint.
 838              */
 839             savecomment = *state->commentptr;
 840             *state->commentptr = NULL;
 841             if (state->ssh2) {
 842                 char *fp;
 843                 fp = state->ssh2key.alg->fingerprint(state->ssh2key.data);
 844                 SetDlgItemText(hwnd, IDC_FINGERPRINT, fp);
 845                 sfree(fp);
 846             } else {
 847                 char buf[128];
 848                 rsa_fingerprint(buf, sizeof(buf), &state->key);
 849                 SetDlgItemText(hwnd, IDC_FINGERPRINT, buf);
 850             }
 851             *state->commentptr = savecomment;
 852             /*
 853              * Construct a decimal representation of the key, for
 854              * pasting into .ssh/authorized_keys on a Unix box.
 855              */
 856             if (state->ssh2) {
 857                 setupbigedit2(hwnd, IDC_KEYDISPLAY, &state->ssh2key);
 858             } else {
 859                 setupbigedit1(hwnd, IDC_KEYDISPLAY, &state->key);
 860             }
 861         }
 862         /*
 863          * Finally, hide the progress bar and show the key data.
 864          */
 865         hidemany(hwnd, nokey_ids, TRUE);
 866         hidemany(hwnd, generating_ids, TRUE);
 867         hidemany(hwnd, gotkey_ids, FALSE);
 868         break;
 869       case WM_CLOSE:
 870         state = (struct MainDlgState *)GetWindowLong(hwnd, GWL_USERDATA);
 871         sfree(state);
 872         EndDialog(hwnd, 1);
 873         return 0;
 874     }
 875     return 0;
 876 }
 877
 878 int WINAPI WinMain(HINSTANCE inst, HINSTANCE prev, LPSTR cmdline, int show) {
 879     InitCommonControls();
 880     hinst = inst;
 881     random_init();
 882     return DialogBox(hinst, MAKEINTRESOURCE(201), NULL, MainDlgProc) != IDOK;
 883 }