Implemented export of OpenSSH keys.
[u/mdw/putty] / puttygen.c
index 1269968..2d2d933 100644 (file)
 
 #define DEFAULT_KEYSIZE 1024
 
+static int requested_help;
+
 /* ----------------------------------------------------------------------
  * Progress report code. This is really horrible :-)
  */
-#define PHASE1TOTAL 0x10000
-#define PHASE2TOTAL 0x10000
-#define PHASE3TOTAL 0x04000
-#define PHASE1START 0
-#define PHASE2START (PHASE1TOTAL)
-#define PHASE3START (PHASE1TOTAL + PHASE2TOTAL)
-#define TOTALTOTAL  (PHASE1TOTAL + PHASE2TOTAL + PHASE3TOTAL)
-#define PROGRESSBIGRANGE 65535
-#define DIVISOR     ((TOTALTOTAL + PROGRESSBIGRANGE - 1) / PROGRESSBIGRANGE)
-#define PROGRESSRANGE (TOTALTOTAL / DIVISOR)
+#define PROGRESSRANGE 65535
+#define MAXPHASE 5
 struct progress {
-    unsigned phase1param, phase1current, phase1n;
-    unsigned phase2param, phase2current, phase2n;
-    unsigned phase3mult;
+    int nphases;
+    struct {
+       int exponential;
+       unsigned startpoint, total;
+       unsigned param, current, n;    /* if exponential */
+       unsigned mult;                 /* if linear */
+    } phases[MAXPHASE];
+    unsigned total, divisor, range;
     HWND progbar;
 };
 
-static void progress_update(void *param, int phase, int iprogress)
+static void progress_update(void *param, int action, int phase, int iprogress)
 {
     struct progress *p = (struct progress *) param;
     unsigned progress = iprogress;
     int position;
 
-    switch (phase) {
-      case -1:
-       p->phase1param = 0x10000 + progress;
-       p->phase1current = 0x10000;
-       p->phase1n = 0;
-       return;
-      case -2:
-       p->phase2param = 0x10000 + progress;
-       p->phase2current = 0x10000;
-       p->phase2n = 0;
-       return;
-      case -3:
-       p->phase3mult = PHASE3TOTAL / progress;
-       return;
-      case 1:
-       while (p->phase1n < progress) {
-           p->phase1n++;
-           p->phase1current *= p->phase1param;
-           p->phase1current /= 0x10000;
-       }
-       position = PHASE1START + 0x10000 - p->phase1current;
+    if (action < PROGFN_READY && p->nphases < phase)
+       p->nphases = phase;
+    switch (action) {
+      case PROGFN_INITIALISE:
+       p->nphases = 0;
+       break;
+      case PROGFN_LIN_PHASE:
+       p->phases[phase-1].exponential = 0;
+       p->phases[phase-1].mult = p->phases[phase].total / progress;
+       break;
+      case PROGFN_EXP_PHASE:
+       p->phases[phase-1].exponential = 1;
+       p->phases[phase-1].param = 0x10000 + progress;
+       p->phases[phase-1].current = p->phases[phase-1].total;
+       p->phases[phase-1].n = 0;
        break;
-      case 2:
-       while (p->phase2n < progress) {
-           p->phase2n++;
-           p->phase2current *= p->phase2param;
-           p->phase2current /= 0x10000;
+      case PROGFN_PHASE_EXTENT:
+       p->phases[phase-1].total = progress;
+       break;
+      case PROGFN_READY:
+       {
+           unsigned total = 0;
+           int i;
+           for (i = 0; i < p->nphases; i++) {
+               p->phases[i].startpoint = total;
+               total += p->phases[i].total;
+           }
+           p->total = total;
+           p->divisor = ((p->total + PROGRESSRANGE - 1) / PROGRESSRANGE);
+           p->range = p->total / p->divisor;
+           SendMessage(p->progbar, PBM_SETRANGE, 0, MAKELPARAM(0, p->range));
        }
-       position = PHASE2START + 0x10000 - p->phase2current;
        break;
-      case 3:
-       position = PHASE3START + progress * p->phase3mult;
+      case PROGFN_PROGRESS:
+       if (p->phases[phase-1].exponential) {
+           while (p->phases[phase-1].n < progress) {
+               p->phases[phase-1].n++;
+               p->phases[phase-1].current *= p->phases[phase-1].param;
+               p->phases[phase-1].current /= 0x10000;
+           }
+           position = (p->phases[phase-1].startpoint +
+                       p->phases[phase-1].total - p->phases[phase-1].current);
+       } else {
+           position = (p->phases[phase-1].startpoint +
+                       progress * p->phases[phase-1].mult);
+       }
+       SendMessage(p->progbar, PBM_SETPOS, position / p->divisor, 0);
        break;
-      default:
-       /*
-        * Shouldn't happen, but having a default clause placates
-        * gcc -Wall, which would otherwise complain that
-        * `position' might be used uninitialised.
-        */
-       return;
     }
-
-    SendMessage(p->progbar, PBM_SETPOS, position / DIVISOR, 0);
 }
 
 extern char ver[];
@@ -291,7 +296,9 @@ struct rsa_key_thread_params {
     HWND progressbar;                 /* notify this with progress */
     HWND dialog;                      /* notify this on completion */
     int keysize;                      /* bits in key */
+    int is_dsa;
     struct RSAKey *key;
+    struct dss_key *dsskey;
 };
 static DWORD WINAPI generate_rsa_key_thread(void *param)
 {
@@ -300,7 +307,12 @@ static DWORD WINAPI generate_rsa_key_thread(void *param)
     struct progress prog;
     prog.progbar = params->progressbar;
 
-    rsa_generate(params->key, params->keysize, progress_update, &prog);
+    progress_update(&prog, PROGFN_INITIALISE, 0, 0);
+
+    if (params->is_dsa)
+       dsa_generate(params->dsskey, params->keysize, progress_update, &prog);
+    else
+       rsa_generate(params->key, params->keysize, progress_update, &prog);
 
     PostMessage(params->dialog, WM_DONEKEY, 0, 0);
 
@@ -314,11 +326,12 @@ struct MainDlgState {
     int key_exists;
     int entropy_got, entropy_required, entropy_size;
     int keysize;
-    int ssh2;
+    int ssh2, is_dsa;
     char **commentptr;                /* points to key.comment or ssh2key.comment */
     struct ssh2_userkey ssh2key;
     unsigned *entropy;
     struct RSAKey key;
+    struct dss_key dsskey;
 };
 
 static void hidemany(HWND hwnd, const int *ids, int hideit)
@@ -395,6 +408,26 @@ static int save_ssh1_pubkey(char *filename, struct RSAKey *key)
     return 1;
 }
 
+/*
+ * Warn about the obsolescent key file format.
+ */
+void old_keyfile_warning(void)
+{
+    static const char mbtitle[] = "PuTTY Key File Warning";
+    static const char message[] =
+       "You are loading an SSH 2 private key which has an\n"
+       "old version of the file format. This means your key\n"
+       "file is not fully tamperproof. Future versions of\n"
+       "PuTTY may stop supporting this private key format,\n"
+       "so we recommend you convert your key to the new\n"
+       "format.\n"
+       "\n"
+       "Once the key is loaded into PuTTYgen, you can perform\n"
+       "this conversion simply by saving it again.";
+
+    MessageBox(NULL, message, mbtitle, MB_OK);
+}
+
 static int save_ssh2_pubkey(char *filename, struct ssh2_userkey *key)
 {
     unsigned char *pub_blob;
@@ -465,9 +498,11 @@ static int CALLBACK MainDlgProc(HWND hwnd, UINT msg,
        IDC_LOADSTATIC, IDC_LOAD,
        IDC_SAVESTATIC, IDC_SAVE, IDC_SAVEPUB,
        IDC_BOX_PARAMS,
-       IDC_TYPESTATIC, IDC_KEYSSH1, IDC_KEYSSH2RSA,
+       IDC_TYPESTATIC, IDC_KEYSSH1, IDC_KEYSSH2RSA, IDC_KEYSSH2DSA,
        IDC_BITSSTATIC, IDC_BITS,
        IDC_ABOUT,
+       IDC_GIVEHELP,
+       IDC_IMPORT, IDC_EXPORT_OPENSSH, IDC_EXPORT_SSHCOM
     };
     static const int nokey_ids[] = { IDC_NOKEY, 0 };
     static const int generating_ids[] =
@@ -487,6 +522,51 @@ static int CALLBACK MainDlgProc(HWND hwnd, UINT msg,
 
     switch (msg) {
       case WM_INITDIALOG:
+        if (help_path)
+            SetWindowLong(hwnd, GWL_EXSTYLE,
+                          GetWindowLong(hwnd, GWL_EXSTYLE) | WS_EX_CONTEXTHELP);
+        else {
+            /*
+             * If we add a Help button, this is where we destroy it
+             * if the help file isn't present.
+             */
+        }
+        requested_help = FALSE;
+
+       {
+           HMENU menu, menu1;
+
+           menu = CreateMenu();
+
+           menu1 = CreateMenu();
+           AppendMenu(menu1, MF_ENABLED, IDC_GENERATE, "&Generate key pair");
+           AppendMenu(menu1, MF_ENABLED, IDC_LOAD, "&Load private key");
+           AppendMenu(menu1, MF_ENABLED, IDC_SAVEPUB, "Save p&ublic key");
+           AppendMenu(menu1, MF_ENABLED, IDC_SAVE, "&Save private key");
+
+           AppendMenu(menu, MF_POPUP | MF_ENABLED, (UINT) menu1, "&File");
+
+           menu1 = CreateMenu();
+           AppendMenu(menu1, MF_ENABLED, IDC_EXPORT_OPENSSH,
+                      "Export &OpenSSH key");
+#if 0
+           AppendMenu(menu1, MF_ENABLED, IDC_EXPORT_SSHCOM,
+                      "Export &ssh.com key");
+#endif
+
+           AppendMenu(menu, MF_POPUP | MF_ENABLED, (UINT) menu1,
+                      "&Export");
+
+           menu1 = CreateMenu();
+           AppendMenu(menu1, MF_ENABLED, IDC_ABOUT, "&About");
+           if (help_path)
+               AppendMenu(menu1, MF_ENABLED, IDC_GIVEHELP, "&Help");
+
+           AppendMenu(menu, MF_POPUP | MF_ENABLED, (UINT) menu1, "&Help");
+
+           SetMenu(hwnd, menu);
+       }
+
        /*
         * Centre the window.
         */
@@ -511,11 +591,9 @@ static int CALLBACK MainDlgProc(HWND hwnd, UINT msg,
        {
            struct ctlpos cp, cp2;
 
-           /* Accelerators used: acglops1rb */
+           /* Accelerators used: acglops1rbd */
 
-           ctlposinit(&cp, hwnd, 10, 10, 10);
-           bartitle(&cp, "Public and private key generation for PuTTY",
-                    IDC_TITLE);
+           ctlposinit(&cp, hwnd, 4, 4, 4);
            beginbox(&cp, "Key", IDC_BOX_KEY);
            cp2 = cp;
            statictext(&cp2, "No key.", 1, IDC_NOKEY);
@@ -524,7 +602,7 @@ static int CALLBACK MainDlgProc(HWND hwnd, UINT msg,
            progressbar(&cp2, IDC_PROGRESS);
            bigeditctrl(&cp,
                        "&Public key for pasting into authorized_keys file:",
-                       IDC_PKSTATIC, IDC_KEYDISPLAY, 7);
+                       IDC_PKSTATIC, IDC_KEYDISPLAY, 5);
            SendDlgItemMessage(hwnd, IDC_KEYDISPLAY, EM_SETREADONLY, 1, 0);
            staticedit(&cp, "Key fingerprint:", IDC_FPSTATIC,
                       IDC_FINGERPRINT, 75);
@@ -547,14 +625,15 @@ static int CALLBACK MainDlgProc(HWND hwnd, UINT msg,
                       "&Save private key", IDC_SAVE);
            endbox(&cp);
            beginbox(&cp, "Parameters", IDC_BOX_PARAMS);
-           radioline(&cp, "Type of key to generate:", IDC_TYPESTATIC, 2,
+           radioline(&cp, "Type of key to generate:", IDC_TYPESTATIC, 3,
                      "SSH&1 (RSA)", IDC_KEYSSH1,
-                     "SSH2 &RSA", IDC_KEYSSH2RSA, NULL);
+                     "SSH2 &RSA", IDC_KEYSSH2RSA,
+                     "SSH2 &DSA", IDC_KEYSSH2DSA, NULL);
            staticedit(&cp, "Number of &bits in a generated key:",
                       IDC_BITSSTATIC, IDC_BITS, 20);
            endbox(&cp);
        }
-       CheckRadioButton(hwnd, IDC_KEYSSH1, IDC_KEYSSH2RSA, IDC_KEYSSH1);
+       CheckRadioButton(hwnd, IDC_KEYSSH1, IDC_KEYSSH2DSA, IDC_KEYSSH1);
        SetDlgItemInt(hwnd, IDC_BITS, DEFAULT_KEYSIZE, FALSE);
 
        /*
@@ -599,7 +678,9 @@ static int CALLBACK MainDlgProc(HWND hwnd, UINT msg,
                params->progressbar = GetDlgItem(hwnd, IDC_PROGRESS);
                params->dialog = hwnd;
                params->keysize = state->keysize;
+               params->is_dsa = state->is_dsa;
                params->key = &state->key;
+               params->dsskey = &state->dsskey;
 
                if (!CreateThread(NULL, 0, generate_rsa_key_thread,
                                  params, 0, &threadid)) {
@@ -642,6 +723,16 @@ static int CALLBACK MainDlgProc(HWND hwnd, UINT msg,
            EnableWindow(hwnd, 1);
            SetActiveWindow(hwnd);
            return 0;
+         case IDC_GIVEHELP:
+            if (HIWORD(wParam) == BN_CLICKED ||
+                HIWORD(wParam) == BN_DOUBLECLICKED) {
+                if (help_path) {
+                    WinHelp(hwnd, help_path, HELP_COMMAND,
+                            (DWORD)"JI(`',`puttygen.general')");
+                    requested_help = TRUE;
+                }
+            }
+           return 0;
          case IDC_GENERATE:
            state =
                (struct MainDlgState *) GetWindowLong(hwnd, GWL_USERDATA);
@@ -652,6 +743,7 @@ static int CALLBACK MainDlgProc(HWND hwnd, UINT msg,
                    state->keysize = DEFAULT_KEYSIZE;
                /* If we ever introduce a new key type, check it here! */
                state->ssh2 = !IsDlgButtonChecked(hwnd, IDC_KEYSSH1);
+               state->is_dsa = IsDlgButtonChecked(hwnd, IDC_KEYSSH2DSA);
                if (state->keysize < 256) {
                    int ret = MessageBox(hwnd,
                                         "PuTTYgen will not generate a key"
@@ -673,6 +765,7 @@ static int CALLBACK MainDlgProc(HWND hwnd, UINT msg,
                EnableWindow(GetDlgItem(hwnd, IDC_SAVEPUB), 0);
                EnableWindow(GetDlgItem(hwnd, IDC_KEYSSH1), 0);
                EnableWindow(GetDlgItem(hwnd, IDC_KEYSSH2RSA), 0);
+               EnableWindow(GetDlgItem(hwnd, IDC_KEYSSH2DSA), 0);
                EnableWindow(GetDlgItem(hwnd, IDC_BITS), 0);
                state->key_exists = FALSE;
                SetDlgItemText(hwnd, IDC_GENERATING, entropy_msg);
@@ -703,12 +796,39 @@ static int CALLBACK MainDlgProc(HWND hwnd, UINT msg,
            }
            break;
          case IDC_SAVE:
+          case IDC_EXPORT_OPENSSH:
+          case IDC_EXPORT_SSHCOM:
            state =
                (struct MainDlgState *) GetWindowLong(hwnd, GWL_USERDATA);
            if (state->key_exists) {
                char filename[FILENAME_MAX];
                char passphrase[PASSPHRASE_MAXLEN];
                char passphrase2[PASSPHRASE_MAXLEN];
+                int type, realtype;
+
+                if (state->ssh2)
+                    realtype = SSH_KEYTYPE_SSH2;
+                else
+                    realtype = SSH_KEYTYPE_SSH1;
+
+                if (LOWORD(wParam) == IDC_EXPORT_OPENSSH)
+                    type = SSH_KEYTYPE_OPENSSH;
+                else if (LOWORD(wParam) == IDC_EXPORT_SSHCOM)
+                    type = SSH_KEYTYPE_SSHCOM;
+                else
+                    type = realtype;
+
+                if (type != realtype &&
+                    import_target_type(type) != realtype) {
+                    char msg[256];
+                    sprintf(msg, "Cannot export an SSH%d key in an SSH%d"
+                            " format", (state->ssh2 ? 2 : 1),
+                            (state->ssh2 ? 1 : 2));
+                   MessageBox(hwnd, msg,
+                               "PuTTYgen Error", MB_OK | MB_ICONERROR);
+                   break;
+                }
+
                GetDlgItemText(hwnd, IDC_PASSPHRASE1EDIT,
                               passphrase, sizeof(passphrase));
                GetDlgItemText(hwnd, IDC_PASSPHRASE2EDIT,
@@ -743,13 +863,22 @@ static int CALLBACK MainDlgProc(HWND hwnd, UINT msg,
                        if (ret != IDYES)
                            break;
                    }
+
                    if (state->ssh2) {
-                       ret = ssh2_save_userkey(filename, &state->ssh2key,
-                                               *passphrase ? passphrase :
-                                               NULL);
+                        if (type != realtype)
+                            ret = export_ssh2(filename, type, &state->ssh2key,
+                                              *passphrase ? passphrase : NULL);
+                        else
+                            ret = ssh2_save_userkey(filename, &state->ssh2key,
+                                                    *passphrase ? passphrase :
+                                                    NULL);
                    } else {
-                       ret = saversakey(filename, &state->key,
-                                        *passphrase ? passphrase : NULL);
+                        if (type != realtype)
+                            ret = export_ssh1(filename, type, &state->key,
+                                              *passphrase ? passphrase : NULL);
+                        else
+                            ret = saversakey(filename, &state->key,
+                                             *passphrase ? passphrase : NULL);
                    }
                    if (ret <= 0) {
                        MessageBox(hwnd, "Unable to save key file",
@@ -797,26 +926,40 @@ static int CALLBACK MainDlgProc(HWND hwnd, UINT msg,
                if (prompt_keyfile(hwnd, "Load private key:", filename, 0)) {
                    char passphrase[PASSPHRASE_MAXLEN];
                    int needs_pass;
-                   int ver;
+                   int type, realtype;
                    int ret;
                    char *comment;
                    struct PassphraseProcStruct pps;
                    struct RSAKey newkey1;
                    struct ssh2_userkey *newkey2 = NULL;
 
-                   ver = keyfile_version(filename);
-                   if (ver == 0) {
-                       MessageBox(NULL, "Couldn't load private key.",
+                   type = realtype = key_type(filename);
+                   if (type != SSH_KEYTYPE_SSH1 &&
+                       type != SSH_KEYTYPE_SSH2 &&
+                       !import_possible(type)) {
+                       char msg[256];
+                       sprintf(msg, "Couldn't load private key (%s)",
+                               key_type_to_str(type));
+                       MessageBox(NULL, msg,
                                   "PuTTYgen Error", MB_OK | MB_ICONERROR);
                        break;
                    }
 
+                   if (type != SSH_KEYTYPE_SSH1 &&
+                       type != SSH_KEYTYPE_SSH2) {
+                       realtype = type;
+                       type = import_target_type(type);
+                   }
+
                    comment = NULL;
-                   if (ver == 1)
+                   if (realtype == SSH_KEYTYPE_SSH1)
                        needs_pass = rsakey_encrypted(filename, &comment);
-                   else
+                   else if (realtype == SSH_KEYTYPE_SSH2)
                        needs_pass =
                            ssh2_userkey_encrypted(filename, &comment);
+                   else
+                       needs_pass = import_encrypted(filename, realtype,
+                                                     &comment);
                    pps.passphrase = passphrase;
                    pps.comment = comment;
                    do {
@@ -832,12 +975,20 @@ static int CALLBACK MainDlgProc(HWND hwnd, UINT msg,
                            }
                        } else
                            *passphrase = '\0';
-                       if (ver == 1)
-                           ret =
-                               loadrsakey(filename, &newkey1, passphrase);
-                       else {
-                           newkey2 =
-                               ssh2_load_userkey(filename, passphrase);
+                       if (type == SSH_KEYTYPE_SSH1) {
+                           if (realtype == type)
+                               ret = loadrsakey(filename, &newkey1,
+                                                passphrase);
+                           else
+                               ret = import_ssh1(filename, realtype,
+                                                 &newkey1, passphrase);
+                       } else {
+                           if (realtype == type)
+                               newkey2 = ssh2_load_userkey(filename,
+                                                           passphrase);
+                           else
+                               newkey2 = import_ssh2(filename, realtype,
+                                                     passphrase);
                            if (newkey2 == SSH2_WRONG_PASSPHRASE)
                                ret = -1;
                            else if (!newkey2)
@@ -858,6 +1009,7 @@ static int CALLBACK MainDlgProc(HWND hwnd, UINT msg,
                        EnableWindow(GetDlgItem(hwnd, IDC_SAVEPUB), 1);
                        EnableWindow(GetDlgItem(hwnd, IDC_KEYSSH1), 1);
                        EnableWindow(GetDlgItem(hwnd, IDC_KEYSSH2RSA), 1);
+                       EnableWindow(GetDlgItem(hwnd, IDC_KEYSSH2DSA), 1);
                        EnableWindow(GetDlgItem(hwnd, IDC_BITS), 1);
                        /*
                         * Now update the key controls with all the
@@ -868,7 +1020,7 @@ static int CALLBACK MainDlgProc(HWND hwnd, UINT msg,
                                           passphrase);
                            SetDlgItemText(hwnd, IDC_PASSPHRASE2EDIT,
                                           passphrase);
-                           if (ver == 1) {
+                           if (type == SSH_KEYTYPE_SSH1) {
                                char buf[128];
                                char *savecomment;
 
@@ -937,18 +1089,25 @@ static int CALLBACK MainDlgProc(HWND hwnd, UINT msg,
        state = (struct MainDlgState *) GetWindowLong(hwnd, GWL_USERDATA);
        state->generation_thread_exists = FALSE;
        state->key_exists = TRUE;
-       SendDlgItemMessage(hwnd, IDC_PROGRESS, PBM_SETPOS, PROGRESSRANGE,
-                          0);
+       SendDlgItemMessage(hwnd, IDC_PROGRESS, PBM_SETRANGE, 0,
+                          MAKELPARAM(0, PROGRESSRANGE));
+       SendDlgItemMessage(hwnd, IDC_PROGRESS, PBM_SETPOS, PROGRESSRANGE, 0);
        EnableWindow(GetDlgItem(hwnd, IDC_GENERATE), 1);
        EnableWindow(GetDlgItem(hwnd, IDC_LOAD), 1);
        EnableWindow(GetDlgItem(hwnd, IDC_SAVE), 1);
        EnableWindow(GetDlgItem(hwnd, IDC_SAVEPUB), 1);
        EnableWindow(GetDlgItem(hwnd, IDC_KEYSSH1), 1);
        EnableWindow(GetDlgItem(hwnd, IDC_KEYSSH2RSA), 1);
+       EnableWindow(GetDlgItem(hwnd, IDC_KEYSSH2DSA), 1);
        EnableWindow(GetDlgItem(hwnd, IDC_BITS), 1);
        if (state->ssh2) {
-           state->ssh2key.data = &state->key;
-           state->ssh2key.alg = &ssh_rsa;
+           if (state->is_dsa) {
+               state->ssh2key.data = &state->dsskey;
+               state->ssh2key.alg = &ssh_dss;
+           } else {
+               state->ssh2key.data = &state->key;
+               state->ssh2key.alg = &ssh_rsa;
+           }
            state->commentptr = &state->ssh2key.comment;
        } else {
            state->commentptr = &state->key.comment;
@@ -965,7 +1124,10 @@ static int CALLBACK MainDlgProc(HWND hwnd, UINT msg,
            struct tm *tm;
            time(&t);
            tm = localtime(&t);
-           strftime(*state->commentptr, 30, "rsa-key-%Y%m%d", tm);
+           if (state->is_dsa)
+               strftime(*state->commentptr, 30, "dsa-key-%Y%m%d", tm);
+           else
+               strftime(*state->commentptr, 30, "rsa-key-%Y%m%d", tm);
        }
 
        /*
@@ -1020,19 +1182,95 @@ static int CALLBACK MainDlgProc(HWND hwnd, UINT msg,
        hidemany(hwnd, generating_ids, TRUE);
        hidemany(hwnd, gotkey_ids, FALSE);
        break;
+      case WM_HELP:
+        if (help_path) {
+            int id = ((LPHELPINFO)lParam)->iCtrlId;
+            char *cmd = NULL;
+            switch (id) {
+              case IDC_GENERATING:
+              case IDC_PROGRESS:
+              case IDC_GENSTATIC:
+              case IDC_GENERATE:
+                cmd = "JI(`',`puttygen.generate')"; break;
+              case IDC_PKSTATIC:
+              case IDC_KEYDISPLAY:
+                cmd = "JI(`',`puttygen.pastekey')"; break;
+              case IDC_FPSTATIC:
+              case IDC_FINGERPRINT:
+                cmd = "JI(`',`puttygen.fingerprint')"; break;
+              case IDC_COMMENTSTATIC:
+              case IDC_COMMENTEDIT:
+                cmd = "JI(`',`puttygen.comment')"; break;
+              case IDC_PASSPHRASE1STATIC:
+              case IDC_PASSPHRASE1EDIT:
+              case IDC_PASSPHRASE2STATIC:
+              case IDC_PASSPHRASE2EDIT:
+                cmd = "JI(`',`puttygen.passphrase')"; break;
+              case IDC_LOADSTATIC:
+              case IDC_LOAD:
+                cmd = "JI(`',`puttygen.load')"; break;
+              case IDC_SAVESTATIC:
+              case IDC_SAVE:
+                cmd = "JI(`',`puttygen.savepriv')"; break;
+              case IDC_SAVEPUB:
+                cmd = "JI(`',`puttygen.savepub')"; break;
+              case IDC_TYPESTATIC:
+              case IDC_KEYSSH1:
+              case IDC_KEYSSH2RSA:
+              case IDC_KEYSSH2DSA:
+                cmd = "JI(`',`puttygen.keytype')"; break;
+              case IDC_BITSSTATIC:
+              case IDC_BITS:
+                cmd = "JI(`',`puttygen.bits')"; break;
+            }
+            if (cmd) {
+                WinHelp(hwnd, help_path, HELP_COMMAND, (DWORD)cmd);
+                requested_help = TRUE;
+            } else {
+                MessageBeep(0);
+            }
+        }
+        break;
       case WM_CLOSE:
        state = (struct MainDlgState *) GetWindowLong(hwnd, GWL_USERDATA);
        sfree(state);
+        if (requested_help) {
+            WinHelp(hwnd, help_path, HELP_QUIT, 0);
+            requested_help = FALSE;
+        }
        EndDialog(hwnd, 1);
        return 0;
     }
     return 0;
 }
 
+void cleanup_exit(int code) { exit(code); }
+
 int WINAPI WinMain(HINSTANCE inst, HINSTANCE prev, LPSTR cmdline, int show)
 {
     InitCommonControls();
     hinst = inst;
+
+    /*
+     * See if we can find our Help file.
+     */
+    {
+        char b[2048], *p, *q, *r;
+        FILE *fp;
+        GetModuleFileName(NULL, b, sizeof(b) - 1);
+        r = b;
+        p = strrchr(b, '\\');
+        if (p && p >= r) r = p+1;
+        q = strrchr(b, ':');
+        if (q && q >= r) r = q+1;
+        strcpy(r, "putty.hlp");
+        if ( (fp = fopen(b, "r")) != NULL) {
+            help_path = dupstr(b);
+            fclose(fp);
+        } else
+            help_path = NULL;
+    }
+
     random_init();
     return DialogBox(hinst, MAKEINTRESOURCE(201), NULL,
                     MainDlgProc) != IDOK;