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 {
  43     struct progress *p = (struct progress *) param;
  44     unsigned progress = iprogress;
  45     int position;
  46
  47     switch (phase) {
  48       case -1:
  49         p->phase1param = 0x10000 + progress;
  50         p->phase1current = 0x10000;
  51         p->phase1n = 0;
  52         return;
  53       case -2:
  54         p->phase2param = 0x10000 + progress;
  55         p->phase2current = 0x10000;
  56         p->phase2n = 0;
  57         return;
  58       case -3:
  59         p->phase3mult = PHASE3TOTAL / progress;
  60         return;
  61       case 1:
  62         while (p->phase1n < progress) {
  63             p->phase1n++;
  64             p->phase1current *= p->phase1param;
  65             p->phase1current /= 0x10000;
  66         }
  67         position = PHASE1START + 0x10000 - p->phase1current;
  68         break;
  69       case 2:
  70         while (p->phase2n < progress) {
  71             p->phase2n++;
  72             p->phase2current *= p->phase2param;
  73             p->phase2current /= 0x10000;
  74         }
  75         position = PHASE2START + 0x10000 - p->phase2current;
  76         break;
  77       case 3:
  78         position = PHASE3START + progress * p->phase3mult;
  79         break;
  80     }
  81
  82     SendMessage(p->progbar, PBM_SETPOS, position / DIVISOR, 0);
  83 }
  84
  85 extern char ver[];
  86
  87 #define PASSPHRASE_MAXLEN 512
  88
  89 struct PassphraseProcStruct {
  90     char *passphrase;
  91     char *comment;
  92 };
  93
  94 /*
  95  * Dialog-box function for the passphrase box.
  96  */
  97 static int CALLBACK PassphraseProc(HWND hwnd, UINT msg,
  98                                    WPARAM wParam, LPARAM lParam)
  99 {
 100     static char *passphrase = NULL;
 101     struct PassphraseProcStruct *p;
 102
 103     switch (msg) {
 104       case WM_INITDIALOG:
 105         SetForegroundWindow(hwnd);
 106         SetWindowPos(hwnd, HWND_TOP, 0, 0, 0, 0,
 107                      SWP_NOMOVE | SWP_NOSIZE | SWP_SHOWWINDOW);
 108
 109         /*
 110          * Centre the window.
 111          */
 112         {                              /* centre the window */
 113             RECT rs, rd;
 114             HWND hw;
 115
 116             hw = GetDesktopWindow();
 117             if (GetWindowRect(hw, &rs) && GetWindowRect(hwnd, &rd))
 118                 MoveWindow(hwnd,
 119                            (rs.right + rs.left + rd.left - rd.right) / 2,
 120                            (rs.bottom + rs.top + rd.top - rd.bottom) / 2,
 121                            rd.right - rd.left, rd.bottom - rd.top, TRUE);
 122         }
 123
 124         p = (struct PassphraseProcStruct *) lParam;
 125         passphrase = p->passphrase;
 126         if (p->comment)
 127             SetDlgItemText(hwnd, 101, p->comment);
 128         *passphrase = 0;
 129         SetDlgItemText(hwnd, 102, passphrase);
 130         return 0;
 131       case WM_COMMAND:
 132         switch (LOWORD(wParam)) {
 133           case IDOK:
 134             if (*passphrase)
 135                 EndDialog(hwnd, 1);
 136             else
 137                 MessageBeep(0);
 138             return 0;
 139           case IDCANCEL:
 140             EndDialog(hwnd, 0);
 141             return 0;
 142           case 102:                    /* edit box */
 143             if ((HIWORD(wParam) == EN_CHANGE) && passphrase) {
 144                 GetDlgItemText(hwnd, 102, passphrase,
 145                                PASSPHRASE_MAXLEN - 1);
 146                 passphrase[PASSPHRASE_MAXLEN - 1] = '\0';
 147             }
 148             return 0;
 149         }
 150         return 0;
 151       case WM_CLOSE:
 152         EndDialog(hwnd, 0);
 153         return 0;
 154     }
 155     return 0;
 156 }
 157
 158 /*
 159  * Prompt for a key file. Assumes the filename buffer is of size
 160  * FILENAME_MAX.
 161  */
 162 static int prompt_keyfile(HWND hwnd, char *dlgtitle,
 163                           char *filename, int save)
 164 {
 165     OPENFILENAME of;
 166     memset(&of, 0, sizeof(of));
 167 #ifdef OPENFILENAME_SIZE_VERSION_400
 168     of.lStructSize = OPENFILENAME_SIZE_VERSION_400;
 169 #else
 170     of.lStructSize = sizeof(of);
 171 #endif
 172     of.hwndOwner = hwnd;
 173     of.lpstrFilter = "All Files\0*\0\0\0";
 174     of.lpstrCustomFilter = NULL;
 175     of.nFilterIndex = 1;
 176     of.lpstrFile = filename;
 177     *filename = '\0';
 178     of.nMaxFile = FILENAME_MAX;
 179     of.lpstrFileTitle = NULL;
 180     of.lpstrInitialDir = NULL;
 181     of.lpstrTitle = dlgtitle;
 182     of.Flags = 0;
 183     if (save)
 184         return GetSaveFileName(&of);
 185     else
 186         return GetOpenFileName(&of);
 187 }
 188
 189 /*
 190  * This function is needed to link with the DES code. We need not
 191  * have it do anything at all.
 192  */
 193 void logevent(char *msg)
 194 {
 195 }
 196
 197 /*
 198  * Dialog-box function for the Licence box.
 199  */
 200 static int CALLBACK LicenceProc(HWND hwnd, UINT msg,
 201                                 WPARAM wParam, LPARAM lParam)
 202 {
 203     switch (msg) {
 204       case WM_INITDIALOG:
 205         /*
 206          * Centre the window.
 207          */
 208         {                              /* centre the window */
 209             RECT rs, rd;
 210             HWND hw;
 211
 212             hw = GetDesktopWindow();
 213             if (GetWindowRect(hw, &rs) && GetWindowRect(hwnd, &rd))
 214                 MoveWindow(hwnd,
 215                            (rs.right + rs.left + rd.left - rd.right) / 2,
 216                            (rs.bottom + rs.top + rd.top - rd.bottom) / 2,
 217                            rd.right - rd.left, rd.bottom - rd.top, TRUE);
 218         }
 219
 220         return 1;
 221       case WM_COMMAND:
 222         switch (LOWORD(wParam)) {
 223           case IDOK:
 224             EndDialog(hwnd, 1);
 225             return 0;
 226         }
 227         return 0;
 228       case WM_CLOSE:
 229         EndDialog(hwnd, 1);
 230         return 0;
 231     }
 232     return 0;
 233 }
 234
 235 /*
 236  * Dialog-box function for the About box.
 237  */
 238 static int CALLBACK AboutProc(HWND hwnd, UINT msg,
 239                               WPARAM wParam, LPARAM lParam)
 240 {
 241     switch (msg) {
 242       case WM_INITDIALOG:
 243         /*
 244          * Centre the window.
 245          */
 246         {                              /* centre the window */
 247             RECT rs, rd;
 248             HWND hw;
 249
 250             hw = GetDesktopWindow();
 251             if (GetWindowRect(hw, &rs) && GetWindowRect(hwnd, &rd))
 252                 MoveWindow(hwnd,
 253                            (rs.right + rs.left + rd.left - rd.right) / 2,
 254                            (rs.bottom + rs.top + rd.top - rd.bottom) / 2,
 255                            rd.right - rd.left, rd.bottom - rd.top, TRUE);
 256         }
 257
 258         SetDlgItemText(hwnd, 100, ver);
 259         return 1;
 260       case WM_COMMAND:
 261         switch (LOWORD(wParam)) {
 262           case IDOK:
 263             EndDialog(hwnd, 1);
 264             return 0;
 265           case 101:
 266             EnableWindow(hwnd, 0);
 267             DialogBox(hinst, MAKEINTRESOURCE(214), NULL, LicenceProc);
 268             EnableWindow(hwnd, 1);
 269             SetActiveWindow(hwnd);
 270             return 0;
 271         }
 272         return 0;
 273       case WM_CLOSE:
 274         EndDialog(hwnd, 1);
 275         return 0;
 276     }
 277     return 0;
 278 }
 279
 280 /*
 281  * Thread to generate a key.
 282  */
 283 struct rsa_key_thread_params {
 284     HWND progressbar;                  /* notify this with progress */
 285     HWND dialog;                       /* notify this on completion */
 286     int keysize;                       /* bits in key */
 287     struct RSAKey *key;
 288 };
 289 static DWORD WINAPI generate_rsa_key_thread(void *param)
 290 {
 291     struct rsa_key_thread_params *params =
 292         (struct rsa_key_thread_params *) param;
 293     struct progress prog;
 294     prog.progbar = params->progressbar;
 295
 296     rsa_generate(params->key, params->keysize, progress_update, &prog);
 297
 298     PostMessage(params->dialog, WM_DONEKEY, 0, 0);
 299
 300     sfree(params);
 301     return 0;
 302 }
 303
 304 struct MainDlgState {
 305     int collecting_entropy;
 306     int generation_thread_exists;
 307     int key_exists;
 308     int entropy_got, entropy_required, entropy_size;
 309     int keysize;
 310     int ssh2;
 311     char **commentptr;                 /* points to key.comment or ssh2key.comment */
 312     struct ssh2_userkey ssh2key;
 313     unsigned *entropy;
 314     struct RSAKey key;
 315 };
 316
 317 static void hidemany(HWND hwnd, const int *ids, int hideit)
 318 {
 319     while (*ids) {
 320         ShowWindow(GetDlgItem(hwnd, *ids++), (hideit ? SW_HIDE : SW_SHOW));
 321     }
 322 }
 323
 324 static void setupbigedit1(HWND hwnd, int id, struct RSAKey *key)
 325 {
 326     char *buffer;
 327     char *dec1, *dec2;
 328
 329     dec1 = bignum_decimal(key->exponent);
 330     dec2 = bignum_decimal(key->modulus);
 331     buffer = smalloc(strlen(dec1) + strlen(dec2) +
 332                      strlen(key->comment) + 30);
 333     sprintf(buffer, "%d %s %s %s",
 334             bignum_bitcount(key->modulus), dec1, dec2, key->comment);
 335     SetDlgItemText(hwnd, id, buffer);
 336     sfree(dec1);
 337     sfree(dec2);
 338     sfree(buffer);
 339 }
 340
 341 static void setupbigedit2(HWND hwnd, int id, struct ssh2_userkey *key)
 342 {
 343     unsigned char *pub_blob;
 344     char *buffer, *p;
 345     int pub_len;
 346     int i;
 347
 348     pub_blob = key->alg->public_blob(key->data, &pub_len);
 349     buffer = smalloc(strlen(key->alg->name) + 4 * ((pub_len + 2) / 3) +
 350                      strlen(key->comment) + 3);
 351     strcpy(buffer, key->alg->name);
 352     p = buffer + strlen(buffer);
 353     *p++ = ' ';
 354     i = 0;
 355     while (i < pub_len) {
 356         int n = (pub_len - i < 3 ? pub_len - i : 3);
 357         base64_encode_atom(pub_blob + i, n, p);
 358         i += n;
 359         p += 4;
 360     }
 361     *p++ = ' ';
 362     strcpy(p, key->comment);
 363     SetDlgItemText(hwnd, id, buffer);
 364     sfree(pub_blob);
 365     sfree(buffer);
 366 }
 367
 368 /*
 369  * Dialog-box function for the main PuTTYgen dialog box.
 370  */
 371 static int CALLBACK MainDlgProc(HWND hwnd, UINT msg,
 372                                 WPARAM wParam, LPARAM lParam)
 373 {
 374     enum {
 375         controlidstart = 100,
 376         IDC_TITLE,
 377         IDC_BOX_KEY,
 378         IDC_NOKEY,
 379         IDC_GENERATING,
 380         IDC_PROGRESS,
 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,
 386         IDC_BOX_ACTIONS,
 387         IDC_GENSTATIC, IDC_GENERATE,
 388         IDC_LOADSTATIC, IDC_LOAD,
 389         IDC_SAVESTATIC, IDC_SAVE,
 390         IDC_BOX_PARAMS,
 391         IDC_TYPESTATIC, IDC_KEYSSH1, IDC_KEYSSH2RSA,
 392         IDC_BITSSTATIC, IDC_BITS,
 393         IDC_ABOUT,
 394     };
 395     static const int nokey_ids[] = { IDC_NOKEY, 0 };
 396     static const int generating_ids[] =
 397         { IDC_GENERATING, IDC_PROGRESS, 0 };
 398     static const int gotkey_ids[] = {
 399         IDC_PKSTATIC, IDC_KEYDISPLAY,
 400         IDC_FPSTATIC, IDC_FINGERPRINT,
 401         IDC_COMMENTSTATIC, IDC_COMMENTEDIT,
 402         IDC_PASSPHRASE1STATIC, IDC_PASSPHRASE1EDIT,
 403         IDC_PASSPHRASE2STATIC, IDC_PASSPHRASE2EDIT, 0
 404     };
 405     static const char generating_msg[] =
 406         "Please wait while a key is generated...";
 407     static const char entropy_msg[] =
 408         "Please generate some randomness by moving the mouse over the blank area.";
 409     struct MainDlgState *state;
 410
 411     switch (msg) {
 412       case WM_INITDIALOG:
 413         /*
 414          * Centre the window.
 415          */
 416         {                              /* centre the window */
 417             RECT rs, rd;
 418             HWND hw;
 419
 420             hw = GetDesktopWindow();
 421             if (GetWindowRect(hw, &rs) && GetWindowRect(hwnd, &rd))
 422                 MoveWindow(hwnd,
 423                            (rs.right + rs.left + rd.left - rd.right) / 2,
 424                            (rs.bottom + rs.top + rd.top - rd.bottom) / 2,
 425                            rd.right - rd.left, rd.bottom - rd.top, TRUE);
 426         }
 427
 428         state = smalloc(sizeof(*state));
 429         state->generation_thread_exists = FALSE;
 430         state->collecting_entropy = FALSE;
 431         state->entropy = NULL;
 432         state->key_exists = FALSE;
 433         SetWindowLong(hwnd, GWL_USERDATA, (LONG) state);
 434         {
 435             struct ctlpos cp, cp2;
 436
 437             /* Accelerators used: acglops */
 438
 439             ctlposinit(&cp, hwnd, 10, 10, 10);
 440             bartitle(&cp, "Public and private key generation for PuTTY",
 441                      IDC_TITLE);
 442             beginbox(&cp, "Key", IDC_BOX_KEY);
 443             cp2 = cp;
 444             statictext(&cp2, "No key.", IDC_NOKEY);
 445             cp2 = cp;
 446             statictext(&cp2, "", IDC_GENERATING);
 447             progressbar(&cp2, IDC_PROGRESS);
 448             bigeditctrl(&cp,
 449                         "&Public key for pasting into authorized_keys file:",
 450                         IDC_PKSTATIC, IDC_KEYDISPLAY, 7);
 451             SendDlgItemMessage(hwnd, IDC_KEYDISPLAY, EM_SETREADONLY, 1, 0);
 452             staticedit(&cp, "Key fingerprint:", IDC_FPSTATIC,
 453                        IDC_FINGERPRINT, 75);
 454             SendDlgItemMessage(hwnd, IDC_FINGERPRINT, EM_SETREADONLY, 1,
 455                                0);
 456             staticedit(&cp, "Key &comment:", IDC_COMMENTSTATIC,
 457                        IDC_COMMENTEDIT, 75);
 458             staticpassedit(&cp, "Key p&assphrase:", IDC_PASSPHRASE1STATIC,
 459                            IDC_PASSPHRASE1EDIT, 75);
 460             staticpassedit(&cp, "C&onfirm passphrase:",
 461                            IDC_PASSPHRASE2STATIC, IDC_PASSPHRASE2EDIT, 75);
 462             endbox(&cp);
 463             beginbox(&cp, "Actions", IDC_BOX_ACTIONS);
 464             staticbtn(&cp, "Generate a public/private key pair",
 465                       IDC_GENSTATIC, "&Generate", IDC_GENERATE);
 466             staticbtn(&cp, "Load an existing private key file",
 467                       IDC_LOADSTATIC, "&Load", IDC_LOAD);
 468             staticbtn(&cp, "Save the generated key to a new file",
 469                       IDC_SAVESTATIC, "&Save", IDC_SAVE);
 470             endbox(&cp);
 471             beginbox(&cp, "Parameters", IDC_BOX_PARAMS);
 472             radioline(&cp, "Type of key to generate:", IDC_TYPESTATIC, 2,
 473                       "SSH&1 (RSA)", IDC_KEYSSH1,
 474                       "SSH2 &RSA", IDC_KEYSSH2RSA, NULL);
 475             staticedit(&cp, "Number of &bits in a generated key:",
 476                        IDC_BITSSTATIC, IDC_BITS, 20);
 477             endbox(&cp);
 478         }
 479         CheckRadioButton(hwnd, IDC_KEYSSH1, IDC_KEYSSH2RSA, IDC_KEYSSH1);
 480         SetDlgItemInt(hwnd, IDC_BITS, DEFAULT_KEYSIZE, FALSE);
 481
 482         /*
 483          * Initially, hide the progress bar and the key display,
 484          * and show the no-key display. Also disable the Save
 485          * button, because with no key we obviously can't save
 486          * anything.
 487          */
 488         hidemany(hwnd, nokey_ids, FALSE);
 489         hidemany(hwnd, generating_ids, TRUE);
 490         hidemany(hwnd, gotkey_ids, TRUE);
 491         EnableWindow(GetDlgItem(hwnd, IDC_SAVE), 0);
 492
 493         return 1;
 494       case WM_MOUSEMOVE:
 495         state = (struct MainDlgState *) GetWindowLong(hwnd, GWL_USERDATA);
 496         if (state->collecting_entropy &&
 497             state->entropy && state->entropy_got < state->entropy_required) {
 498             state->entropy[state->entropy_got++] = lParam;
 499             state->entropy[state->entropy_got++] = GetMessageTime();
 500             SendDlgItemMessage(hwnd, IDC_PROGRESS, PBM_SETPOS,
 501                                state->entropy_got, 0);
 502             if (state->entropy_got >= state->entropy_required) {
 503                 struct rsa_key_thread_params *params;
 504                 DWORD threadid;
 505
 506                 /*
 507                  * Seed the entropy pool
 508                  */
 509                 random_add_heavynoise(state->entropy, state->entropy_size);
 510                 memset(state->entropy, 0, state->entropy_size);
 511                 sfree(state->entropy);
 512                 state->collecting_entropy = FALSE;
 513
 514                 SetDlgItemText(hwnd, IDC_GENERATING, generating_msg);
 515                 SendDlgItemMessage(hwnd, IDC_PROGRESS, PBM_SETRANGE, 0,
 516                                    MAKELPARAM(0, PROGRESSRANGE));
 517                 SendDlgItemMessage(hwnd, IDC_PROGRESS, PBM_SETPOS, 0, 0);
 518
 519                 params = smalloc(sizeof(*params));
 520                 params->progressbar = GetDlgItem(hwnd, IDC_PROGRESS);
 521                 params->dialog = hwnd;
 522                 params->keysize = state->keysize;
 523                 params->key = &state->key;
 524
 525                 if (!CreateThread(NULL, 0, generate_rsa_key_thread,
 526                                   params, 0, &threadid)) {
 527                     MessageBox(hwnd, "Out of thread resources",
 528                                "Key generation error",
 529                                MB_OK | MB_ICONERROR);
 530                     sfree(params);
 531                 } else {
 532                     state->generation_thread_exists = TRUE;
 533                 }
 534             }
 535         }
 536         break;
 537       case WM_COMMAND:
 538         switch (LOWORD(wParam)) {
 539           case IDC_COMMENTEDIT:
 540             if (HIWORD(wParam) == EN_CHANGE) {
 541                 state = (struct MainDlgState *)
 542                     GetWindowLong(hwnd, GWL_USERDATA);
 543                 if (state->key_exists) {
 544                     HWND editctl = GetDlgItem(hwnd, IDC_COMMENTEDIT);
 545                     int len = GetWindowTextLength(editctl);
 546                     if (*state->commentptr)
 547                         sfree(*state->commentptr);
 548                     *state->commentptr = smalloc(len + 1);
 549                     GetWindowText(editctl, *state->commentptr, len + 1);
 550                     if (state->ssh2) {
 551                         setupbigedit2(hwnd, IDC_KEYDISPLAY,
 552                                       &state->ssh2key);
 553                     } else {
 554                         setupbigedit1(hwnd, IDC_KEYDISPLAY, &state->key);
 555                     }
 556                 }
 557             }
 558             break;
 559           case IDC_ABOUT:
 560             EnableWindow(hwnd, 0);
 561             DialogBox(hinst, MAKEINTRESOURCE(213), NULL, AboutProc);
 562             EnableWindow(hwnd, 1);
 563             SetActiveWindow(hwnd);
 564             return 0;
 565           case IDC_GENERATE:
 566             state =
 567                 (struct MainDlgState *) GetWindowLong(hwnd, GWL_USERDATA);
 568             if (!state->generation_thread_exists) {
 569                 BOOL ok;
 570                 state->keysize = GetDlgItemInt(hwnd, IDC_BITS, &ok, FALSE);
 571                 if (!ok)
 572                     state->keysize = DEFAULT_KEYSIZE;
 573                 /* If we ever introduce a new key type, check it here! */
 574                 state->ssh2 = !IsDlgButtonChecked(hwnd, IDC_KEYSSH1);
 575                 if (state->keysize < 256) {
 576                     int ret = MessageBox(hwnd,
 577                                          "PuTTYgen will not generate a key"
 578                                          " smaller than 256 bits.\n"
 579                                          "Key length reset to 256. Continue?",
 580                                          "PuTTYgen Warning",
 581                                          MB_ICONWARNING | MB_OKCANCEL);
 582                     if (ret != IDOK)
 583                         break;
 584                     state->keysize = 256;
 585                     SetDlgItemInt(hwnd, IDC_BITS, 256, FALSE);
 586                 }
 587                 hidemany(hwnd, nokey_ids, TRUE);
 588                 hidemany(hwnd, generating_ids, FALSE);
 589                 hidemany(hwnd, gotkey_ids, TRUE);
 590                 EnableWindow(GetDlgItem(hwnd, IDC_GENERATE), 0);
 591                 EnableWindow(GetDlgItem(hwnd, IDC_LOAD), 0);
 592                 EnableWindow(GetDlgItem(hwnd, IDC_SAVE), 0);
 593                 state->key_exists = FALSE;
 594                 SetDlgItemText(hwnd, IDC_GENERATING, entropy_msg);
 595                 state->collecting_entropy = TRUE;
 596
 597                 /*
 598                  * My brief statistical tests on mouse movements
 599                  * suggest that there are about 2.5 bits of
 600                  * randomness in the x position, 2.5 in the y
 601                  * position, and 1.7 in the message time, making
 602                  * 5.7 bits of unpredictability per mouse movement.
 603                  * However, other people have told me it's far less
 604                  * than that, so I'm going to be stupidly cautious
 605                  * and knock that down to a nice round 2. With this
 606                  * method, we require two words per mouse movement,
 607                  * so with 2 bits per mouse movement we expect 2
 608                  * bits every 2 words.
 609                  */
 610                 state->entropy_required = (state->keysize / 2) * 2;
 611                 state->entropy_got = 0;
 612                 state->entropy_size = (state->entropy_required *
 613                                        sizeof(*state->entropy));
 614                 state->entropy = smalloc(state->entropy_size);
 615
 616                 SendDlgItemMessage(hwnd, IDC_PROGRESS, PBM_SETRANGE, 0,
 617                                    MAKELPARAM(0, state->entropy_required));
 618                 SendDlgItemMessage(hwnd, IDC_PROGRESS, PBM_SETPOS, 0, 0);
 619             }
 620             break;
 621           case IDC_SAVE:
 622             state =
 623                 (struct MainDlgState *) GetWindowLong(hwnd, GWL_USERDATA);
 624             if (state->key_exists) {
 625                 char filename[FILENAME_MAX];
 626                 char passphrase[PASSPHRASE_MAXLEN];
 627                 char passphrase2[PASSPHRASE_MAXLEN];
 628                 GetDlgItemText(hwnd, IDC_PASSPHRASE1EDIT,
 629                                passphrase, sizeof(passphrase));
 630                 GetDlgItemText(hwnd, IDC_PASSPHRASE2EDIT,
 631                                passphrase2, sizeof(passphrase2));
 632                 if (strcmp(passphrase, passphrase2)) {
 633                     MessageBox(hwnd,
 634                                "The two passphrases given do not match.",
 635                                "PuTTYgen Error", MB_OK | MB_ICONERROR);
 636                     break;
 637                 }
 638                 if (!*passphrase) {
 639                     int ret;
 640                     ret = MessageBox(hwnd,
 641                                      "Are you sure you want to save this key\n"
 642                                      "without a passphrase to protect it?",
 643                                      "PuTTYgen Warning",
 644                                      MB_YESNO | MB_ICONWARNING);
 645                     if (ret != IDYES)
 646                         break;
 647                 }
 648                 if (prompt_keyfile(hwnd, "Save private key as:",
 649                                    filename, 1)) {
 650                     int ret;
 651                     FILE *fp = fopen(filename, "r");
 652                     if (fp) {
 653                         char buffer[FILENAME_MAX + 80];
 654                         fclose(fp);
 655                         sprintf(buffer, "Overwrite existing file\n%.*s?",
 656                                 FILENAME_MAX, filename);
 657                         ret = MessageBox(hwnd, buffer, "PuTTYgen Warning",
 658                                          MB_YESNO | MB_ICONWARNING);
 659                         if (ret != IDYES)
 660                             break;
 661                     }
 662                     if (state->ssh2) {
 663                         ret = ssh2_save_userkey(filename, &state->ssh2key,
 664                                                 *passphrase ? passphrase :
 665                                                 NULL);
 666                     } else {
 667                         ret = saversakey(filename, &state->key,
 668                                          *passphrase ? passphrase : NULL);
 669                     }
 670                     if (ret <= 0) {
 671                         MessageBox(hwnd, "Unable to save key file",
 672                                    "PuTTYgen Error", MB_OK | MB_ICONERROR);
 673                     }
 674                 }
 675             }
 676             break;
 677           case IDC_LOAD:
 678             state =
 679                 (struct MainDlgState *) GetWindowLong(hwnd, GWL_USERDATA);
 680             if (!state->generation_thread_exists) {
 681                 char filename[FILENAME_MAX];
 682                 if (prompt_keyfile(hwnd, "Load private key:", filename, 0)) {
 683                     char passphrase[PASSPHRASE_MAXLEN];
 684                     int needs_pass;
 685                     int ver;
 686                     int ret;
 687                     char *comment;
 688                     struct PassphraseProcStruct pps;
 689                     struct RSAKey newkey1;
 690                     struct ssh2_userkey *newkey2;
 691
 692                     ver = keyfile_version(filename);
 693                     if (ver == 0) {
 694                         MessageBox(NULL, "Couldn't load private key.",
 695                                    "PuTTYgen Error", MB_OK | MB_ICONERROR);
 696                         break;
 697                     }
 698
 699                     comment = NULL;
 700                     if (ver == 1)
 701                         needs_pass = rsakey_encrypted(filename, &comment);
 702                     else
 703                         needs_pass =
 704                             ssh2_userkey_encrypted(filename, &comment);
 705                     pps.passphrase = passphrase;
 706                     pps.comment = comment;
 707                     do {
 708                         if (needs_pass) {
 709                             int dlgret;
 710                             dlgret = DialogBoxParam(hinst,
 711                                                     MAKEINTRESOURCE(210),
 712                                                     NULL, PassphraseProc,
 713                                                     (LPARAM) & pps);
 714                             if (!dlgret) {
 715                                 ret = -2;
 716                                 break;
 717                             }
 718                         } else
 719                             *passphrase = '\0';
 720                         if (ver == 1)
 721                             ret =
 722                                 loadrsakey(filename, &newkey1, passphrase);
 723                         else {
 724                             newkey2 =
 725                                 ssh2_load_userkey(filename, passphrase);
 726                             if (newkey2 == SSH2_WRONG_PASSPHRASE)
 727                                 ret = -1;
 728                             else if (!newkey2)
 729                                 ret = 0;
 730                             else
 731                                 ret = 1;
 732                         }
 733                     } while (ret == -1);
 734                     if (comment)
 735                         sfree(comment);
 736                     if (ret == 0) {
 737                         MessageBox(NULL, "Couldn't load private key.",
 738                                    "PuTTYgen Error", MB_OK | MB_ICONERROR);
 739                     } else if (ret == 1) {
 740                         EnableWindow(GetDlgItem(hwnd, IDC_GENERATE), 1);
 741                         EnableWindow(GetDlgItem(hwnd, IDC_LOAD), 1);
 742                         EnableWindow(GetDlgItem(hwnd, IDC_SAVE), 1);
 743                         /*
 744                          * Now update the key controls with all the
 745                          * key data.
 746                          */
 747                         {
 748                             SetDlgItemText(hwnd, IDC_PASSPHRASE1EDIT,
 749                                            passphrase);
 750                             SetDlgItemText(hwnd, IDC_PASSPHRASE2EDIT,
 751                                            passphrase);
 752                             if (ver == 1) {
 753                                 char buf[128];
 754                                 char *savecomment;
 755
 756                                 state->ssh2 = FALSE;
 757                                 state->commentptr = &state->key.comment;
 758                                 state->key = newkey1;
 759
 760                                 /*
 761                                  * Set the key fingerprint.
 762                                  */
 763                                 savecomment = state->key.comment;
 764                                 state->key.comment = NULL;
 765                                 rsa_fingerprint(buf, sizeof(buf),
 766                                                 &state->key);
 767                                 state->key.comment = savecomment;
 768
 769                                 SetDlgItemText(hwnd, IDC_FINGERPRINT, buf);
 770                                 /*
 771                                  * Construct a decimal representation
 772                                  * of the key, for pasting into
 773                                  * .ssh/authorized_keys on a Unix box.
 774                                  */
 775                                 setupbigedit1(hwnd, IDC_KEYDISPLAY,
 776                                               &state->key);
 777                             } else {
 778                                 char *fp;
 779                                 char *savecomment;
 780
 781                                 state->ssh2 = TRUE;
 782                                 state->commentptr =
 783                                     &state->ssh2key.comment;
 784                                 state->ssh2key = *newkey2;      /* structure copy */
 785                                 sfree(newkey2);
 786
 787                                 savecomment = state->ssh2key.comment;
 788                                 state->ssh2key.comment = NULL;
 789                                 fp =
 790                                     state->ssh2key.alg->
 791                                     fingerprint(state->ssh2key.data);
 792                                 state->ssh2key.comment = savecomment;
 793
 794                                 SetDlgItemText(hwnd, IDC_FINGERPRINT, fp);
 795                                 sfree(fp);
 796
 797                                 setupbigedit2(hwnd, IDC_KEYDISPLAY,
 798                                               &state->ssh2key);
 799                             }
 800                             SetDlgItemText(hwnd, IDC_COMMENTEDIT,
 801                                            *state->commentptr);
 802                         }
 803                         /*
 804                          * Finally, hide the progress bar and show
 805                          * the key data.
 806                          */
 807                         hidemany(hwnd, nokey_ids, TRUE);
 808                         hidemany(hwnd, generating_ids, TRUE);
 809                         hidemany(hwnd, gotkey_ids, FALSE);
 810                         state->key_exists = TRUE;
 811                     }
 812                 }
 813             }
 814             break;
 815         }
 816         return 0;
 817       case WM_DONEKEY:
 818         state = (struct MainDlgState *) GetWindowLong(hwnd, GWL_USERDATA);
 819         state->generation_thread_exists = FALSE;
 820         state->key_exists = TRUE;
 821         SendDlgItemMessage(hwnd, IDC_PROGRESS, PBM_SETPOS, PROGRESSRANGE,
 822                            0);
 823         EnableWindow(GetDlgItem(hwnd, IDC_GENERATE), 1);
 824         EnableWindow(GetDlgItem(hwnd, IDC_LOAD), 1);
 825         EnableWindow(GetDlgItem(hwnd, IDC_SAVE), 1);
 826         if (state->ssh2) {
 827             state->ssh2key.data = &state->key;
 828             state->ssh2key.alg = &ssh_rsa;
 829             state->commentptr = &state->ssh2key.comment;
 830         } else {
 831             state->commentptr = &state->key.comment;
 832         }
 833         /*
 834          * Invent a comment for the key. We'll do this by including
 835          * the date in it. This will be so horrifyingly ugly that
 836          * the user will immediately want to change it, which is
 837          * what we want :-)
 838          */
 839         *state->commentptr = smalloc(30);
 840         {
 841             time_t t;
 842             struct tm *tm;
 843             time(&t);
 844             tm = localtime(&t);
 845             strftime(*state->commentptr, 30, "rsa-key-%Y%m%d", tm);
 846         }
 847
 848         /*
 849          * Now update the key controls with all the key data.
 850          */
 851         {
 852             char *savecomment;
 853             /*
 854              * Blank passphrase, initially. This isn't dangerous,
 855              * because we will warn (Are You Sure?) before allowing
 856              * the user to save an unprotected private key.
 857              */
 858             SetDlgItemText(hwnd, IDC_PASSPHRASE1EDIT, "");
 859             SetDlgItemText(hwnd, IDC_PASSPHRASE2EDIT, "");
 860             /*
 861              * Set the comment.
 862              */
 863             SetDlgItemText(hwnd, IDC_COMMENTEDIT, *state->commentptr);
 864             /*
 865              * Set the key fingerprint.
 866              */
 867             savecomment = *state->commentptr;
 868             *state->commentptr = NULL;
 869             if (state->ssh2) {
 870                 char *fp;
 871                 fp = state->ssh2key.alg->fingerprint(state->ssh2key.data);
 872                 SetDlgItemText(hwnd, IDC_FINGERPRINT, fp);
 873                 sfree(fp);
 874             } else {
 875                 char buf[128];
 876                 rsa_fingerprint(buf, sizeof(buf), &state->key);
 877                 SetDlgItemText(hwnd, IDC_FINGERPRINT, buf);
 878             }
 879             *state->commentptr = savecomment;
 880             /*
 881              * Construct a decimal representation of the key, for
 882              * pasting into .ssh/authorized_keys on a Unix box.
 883              */
 884             if (state->ssh2) {
 885                 setupbigedit2(hwnd, IDC_KEYDISPLAY, &state->ssh2key);
 886             } else {
 887                 setupbigedit1(hwnd, IDC_KEYDISPLAY, &state->key);
 888             }
 889         }
 890         /*
 891          * Finally, hide the progress bar and show the key data.
 892          */
 893         hidemany(hwnd, nokey_ids, TRUE);
 894         hidemany(hwnd, generating_ids, TRUE);
 895         hidemany(hwnd, gotkey_ids, FALSE);
 896         break;
 897       case WM_CLOSE:
 898         state = (struct MainDlgState *) GetWindowLong(hwnd, GWL_USERDATA);
 899         sfree(state);
 900         EndDialog(hwnd, 1);
 901         return 0;
 902     }
 903     return 0;
 904 }
 905
 906 int WINAPI WinMain(HINSTANCE inst, HINSTANCE prev, LPSTR cmdline, int show)
 907 {
 908     InitCommonControls();
 909     hinst = inst;
 910     random_init();
 911     return DialogBox(hinst, MAKEINTRESOURCE(201), NULL,
 912                      MainDlgProc) != IDOK;
 913 }