[sgt/putty] / puttygen.c

/*
 * PuTTY key generation front end.
 */

#include <windows.h>
#include <commctrl.h>
#include <time.h>
#include <stdio.h>
#include <stdlib.h>

#define PUTTY_DO_GLOBALS

#include "putty.h"
#include "ssh.h"
#include "winstuff.h"

#define WM_DONEKEY (WM_XUSER + 1)

#define DEFAULT_KEYSIZE 1024

/* ----------------------------------------------------------------------
 * 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)
struct progress {
    unsigned phase1param, phase1current, phase1n;
    unsigned phase2param, phase2current, phase2n;
    unsigned phase3mult;
    HWND progbar;
};

static void progress_update(void *param, 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;
	break;
      case 2:
	while (p->phase2n < progress) {
	    p->phase2n++;
	    p->phase2current *= p->phase2param;
	    p->phase2current /= 0x10000;
	}
	position = PHASE2START + 0x10000 - p->phase2current;
	break;
      case 3:
	position = PHASE3START + progress * p->phase3mult;
	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[];

#define PASSPHRASE_MAXLEN 512

struct PassphraseProcStruct {
    char *passphrase;
    char *comment;
};

/*
 * Dialog-box function for the passphrase box.
 */
static int CALLBACK PassphraseProc(HWND hwnd, UINT msg,
				   WPARAM wParam, LPARAM lParam)
{
    static char *passphrase = NULL;
    struct PassphraseProcStruct *p;

    switch (msg) {
      case WM_INITDIALOG:
	SetForegroundWindow(hwnd);
	SetWindowPos(hwnd, HWND_TOP, 0, 0, 0, 0,
		     SWP_NOMOVE | SWP_NOSIZE | SWP_SHOWWINDOW);

	/*
	 * Centre the window.
	 */
	{			       /* centre the window */
	    RECT rs, rd;
	    HWND hw;

	    hw = GetDesktopWindow();
	    if (GetWindowRect(hw, &rs) && GetWindowRect(hwnd, &rd))
		MoveWindow(hwnd,
			   (rs.right + rs.left + rd.left - rd.right) / 2,
			   (rs.bottom + rs.top + rd.top - rd.bottom) / 2,
			   rd.right - rd.left, rd.bottom - rd.top, TRUE);
	}

	p = (struct PassphraseProcStruct *) lParam;
	passphrase = p->passphrase;
	if (p->comment)
	    SetDlgItemText(hwnd, 101, p->comment);
	*passphrase = 0;
	SetDlgItemText(hwnd, 102, passphrase);
	return 0;
      case WM_COMMAND:
	switch (LOWORD(wParam)) {
	  case IDOK:
	    if (*passphrase)
		EndDialog(hwnd, 1);
	    else
		MessageBeep(0);
	    return 0;
	  case IDCANCEL:
	    EndDialog(hwnd, 0);
	    return 0;
	  case 102:		       /* edit box */
	    if ((HIWORD(wParam) == EN_CHANGE) && passphrase) {
		GetDlgItemText(hwnd, 102, passphrase,
			       PASSPHRASE_MAXLEN - 1);
		passphrase[PASSPHRASE_MAXLEN - 1] = '\0';
	    }
	    return 0;
	}
	return 0;
      case WM_CLOSE:
	EndDialog(hwnd, 0);
	return 0;
    }
    return 0;
}

/*
 * Prompt for a key file. Assumes the filename buffer is of size
 * FILENAME_MAX.
 */
static int prompt_keyfile(HWND hwnd, char *dlgtitle,
			  char *filename, int save)
{
    OPENFILENAME of;
    memset(&of, 0, sizeof(of));
#ifdef OPENFILENAME_SIZE_VERSION_400
    of.lStructSize = OPENFILENAME_SIZE_VERSION_400;
#else
    of.lStructSize = sizeof(of);
#endif
    of.hwndOwner = hwnd;
    of.lpstrFilter = "All Files\0*\0\0\0";
    of.lpstrCustomFilter = NULL;
    of.nFilterIndex = 1;
    of.lpstrFile = filename;
    *filename = '\0';
    of.nMaxFile = FILENAME_MAX;
    of.lpstrFileTitle = NULL;
    of.lpstrInitialDir = NULL;
    of.lpstrTitle = dlgtitle;
    of.Flags = 0;
    if (save)
	return GetSaveFileName(&of);
    else
	return GetOpenFileName(&of);
}

/*
 * This function is needed to link with the DES code. We need not
 * have it do anything at all.
 */
void logevent(char *msg)
{
}

/*
 * Dialog-box function for the Licence box.
 */
static int CALLBACK LicenceProc(HWND hwnd, UINT msg,
				WPARAM wParam, LPARAM lParam)
{
    switch (msg) {
      case WM_INITDIALOG:
	/*
	 * Centre the window.
	 */
	{			       /* centre the window */
	    RECT rs, rd;
	    HWND hw;

	    hw = GetDesktopWindow();
	    if (GetWindowRect(hw, &rs) && GetWindowRect(hwnd, &rd))
		MoveWindow(hwnd,
			   (rs.right + rs.left + rd.left - rd.right) / 2,
			   (rs.bottom + rs.top + rd.top - rd.bottom) / 2,
			   rd.right - rd.left, rd.bottom - rd.top, TRUE);
	}

	return 1;
      case WM_COMMAND:
	switch (LOWORD(wParam)) {
	  case IDOK:
	    EndDialog(hwnd, 1);
	    return 0;
	}
	return 0;
      case WM_CLOSE:
	EndDialog(hwnd, 1);
	return 0;
    }
    return 0;
}

/*
 * Dialog-box function for the About box.
 */
static int CALLBACK AboutProc(HWND hwnd, UINT msg,
			      WPARAM wParam, LPARAM lParam)
{
    switch (msg) {
      case WM_INITDIALOG:
	/*
	 * Centre the window.
	 */
	{			       /* centre the window */
	    RECT rs, rd;
	    HWND hw;

	    hw = GetDesktopWindow();
	    if (GetWindowRect(hw, &rs) && GetWindowRect(hwnd, &rd))
		MoveWindow(hwnd,
			   (rs.right + rs.left + rd.left - rd.right) / 2,
			   (rs.bottom + rs.top + rd.top - rd.bottom) / 2,
			   rd.right - rd.left, rd.bottom - rd.top, TRUE);
	}

	SetDlgItemText(hwnd, 100, ver);
	return 1;
      case WM_COMMAND:
	switch (LOWORD(wParam)) {
	  case IDOK:
	    EndDialog(hwnd, 1);
	    return 0;
	  case 101:
	    EnableWindow(hwnd, 0);
	    DialogBox(hinst, MAKEINTRESOURCE(214), NULL, LicenceProc);
	    EnableWindow(hwnd, 1);
	    SetActiveWindow(hwnd);
	    return 0;
	}
	return 0;
      case WM_CLOSE:
	EndDialog(hwnd, 1);
	return 0;
    }
    return 0;
}

/*
 * Thread to generate a key.
 */
struct rsa_key_thread_params {
    HWND progressbar;		       /* notify this with progress */
    HWND dialog;		       /* notify this on completion */
    int keysize;		       /* bits in key */
    struct RSAKey *key;
};
static DWORD WINAPI generate_rsa_key_thread(void *param)
{
    struct rsa_key_thread_params *params =
	(struct rsa_key_thread_params *) param;
    struct progress prog;
    prog.progbar = params->progressbar;

    rsa_generate(params->key, params->keysize, progress_update, &prog);

    PostMessage(params->dialog, WM_DONEKEY, 0, 0);

    sfree(params);
    return 0;
}

struct MainDlgState {
    int collecting_entropy;
    int generation_thread_exists;
    int key_exists;
    int entropy_got, entropy_required, entropy_size;
    int keysize;
    int ssh2;
    char **commentptr;		       /* points to key.comment or ssh2key.comment */
    struct ssh2_userkey ssh2key;
    unsigned *entropy;
    struct RSAKey key;
};

static void hidemany(HWND hwnd, const int *ids, int hideit)
{
    while (*ids) {
	ShowWindow(GetDlgItem(hwnd, *ids++), (hideit ? SW_HIDE : SW_SHOW));
    }
}

static void setupbigedit1(HWND hwnd, int id, int idstatic, struct RSAKey *key)
{
    char *buffer;
    char *dec1, *dec2;

    dec1 = bignum_decimal(key->exponent);
    dec2 = bignum_decimal(key->modulus);
    buffer = smalloc(strlen(dec1) + strlen(dec2) +
		     strlen(key->comment) + 30);
    sprintf(buffer, "%d %s %s %s",
	    bignum_bitcount(key->modulus), dec1, dec2, key->comment);
    SetDlgItemText(hwnd, id, buffer);
    SetDlgItemText(hwnd, idstatic,
		   "&Public key for pasting into authorized_keys file:");
    sfree(dec1);
    sfree(dec2);
    sfree(buffer);
}

static void setupbigedit2(HWND hwnd, int id, int idstatic,
			  struct ssh2_userkey *key)
{
    unsigned char *pub_blob;
    char *buffer, *p;
    int pub_len;
    int i;

    pub_blob = key->alg->public_blob(key->data, &pub_len);
    buffer = smalloc(strlen(key->alg->name) + 4 * ((pub_len + 2) / 3) +
		     strlen(key->comment) + 3);
    strcpy(buffer, key->alg->name);
    p = buffer + strlen(buffer);
    *p++ = ' ';
    i = 0;
    while (i < pub_len) {
	int n = (pub_len - i < 3 ? pub_len - i : 3);
	base64_encode_atom(pub_blob + i, n, p);
	i += n;
	p += 4;
    }
    *p++ = ' ';
    strcpy(p, key->comment);
    SetDlgItemText(hwnd, id, buffer);
    SetDlgItemText(hwnd, idstatic, "&Public key for pasting into "
		   "OpenSSH authorized_keys2 file:");
    sfree(pub_blob);
    sfree(buffer);
}

static int save_ssh1_pubkey(char *filename, struct RSAKey *key)
{
    char *dec1, *dec2;
    FILE *fp;

    dec1 = bignum_decimal(key->exponent);
    dec2 = bignum_decimal(key->modulus);
    fp = fopen(filename, "wb");
    if (!fp)
	return 0;
    fprintf(fp, "%d %s %s %s\n",
	    bignum_bitcount(key->modulus), dec1, dec2, key->comment);
    fclose(fp);
    sfree(dec1);
    sfree(dec2);
    return 1;
}

static int save_ssh2_pubkey(char *filename, struct ssh2_userkey *key)
{
    unsigned char *pub_blob;
    char *p;
    int pub_len;
    int i, column;
    FILE *fp;

    pub_blob = key->alg->public_blob(key->data, &pub_len);

    fp = fopen(filename, "wb");
    if (!fp)
	return 0;

    fprintf(fp, "---- BEGIN SSH2 PUBLIC KEY ----\n");

    fprintf(fp, "Comment: \"");
    for (p = key->comment; *p; p++) {
	if (*p == '\\' || *p == '\"')
	    fputc('\\', fp);
	fputc(*p, fp);
    }
    fprintf(fp, "\"\n");

    i = 0;
    column = 0;
    while (i < pub_len) {
	char buf[5];
	int n = (pub_len - i < 3 ? pub_len - i : 3);
	base64_encode_atom(pub_blob + i, n, buf);
	i += n;
	buf[4] = '\0';
	fputs(buf, fp);
	if (++column >= 16) {
	    fputc('\n', fp);
	    column = 0;
	}
    }
    if (column > 0)
	fputc('\n', fp);
    
    fprintf(fp, "---- END SSH2 PUBLIC KEY ----\n");
    fclose(fp);
    sfree(pub_blob);
    return 1;
}

/*
 * Dialog-box function for the main PuTTYgen dialog box.
 */
static int CALLBACK MainDlgProc(HWND hwnd, UINT msg,
				WPARAM wParam, LPARAM lParam)
{
    enum {
	controlidstart = 100,
	IDC_TITLE,
	IDC_BOX_KEY,
	IDC_NOKEY,
	IDC_GENERATING,
	IDC_PROGRESS,
	IDC_PKSTATIC, IDC_KEYDISPLAY,
	IDC_FPSTATIC, IDC_FINGERPRINT,
	IDC_COMMENTSTATIC, IDC_COMMENTEDIT,
	IDC_PASSPHRASE1STATIC, IDC_PASSPHRASE1EDIT,
	IDC_PASSPHRASE2STATIC, IDC_PASSPHRASE2EDIT,
	IDC_BOX_ACTIONS,
	IDC_GENSTATIC, IDC_GENERATE,
	IDC_LOADSTATIC, IDC_LOAD,
	IDC_SAVESTATIC, IDC_SAVE, IDC_SAVEPUB,
	IDC_BOX_PARAMS,
	IDC_TYPESTATIC, IDC_KEYSSH1, IDC_KEYSSH2RSA,
	IDC_BITSSTATIC, IDC_BITS,
	IDC_ABOUT,
    };
    static const int nokey_ids[] = { IDC_NOKEY, 0 };
    static const int generating_ids[] =
	{ IDC_GENERATING, IDC_PROGRESS, 0 };
    static const int gotkey_ids[] = {
	IDC_PKSTATIC, IDC_KEYDISPLAY,
	IDC_FPSTATIC, IDC_FINGERPRINT,
	IDC_COMMENTSTATIC, IDC_COMMENTEDIT,
	IDC_PASSPHRASE1STATIC, IDC_PASSPHRASE1EDIT,
	IDC_PASSPHRASE2STATIC, IDC_PASSPHRASE2EDIT, 0
    };
    static const char generating_msg[] =
	"Please wait while a key is generated...";
    static const char entropy_msg[] =
	"Please generate some randomness by moving the mouse over the blank area.";
    struct MainDlgState *state;

    switch (msg) {
      case WM_INITDIALOG:
	/*
	 * Centre the window.
	 */
	{			       /* centre the window */
	    RECT rs, rd;
	    HWND hw;

	    hw = GetDesktopWindow();
	    if (GetWindowRect(hw, &rs) && GetWindowRect(hwnd, &rd))
		MoveWindow(hwnd,
			   (rs.right + rs.left + rd.left - rd.right) / 2,
			   (rs.bottom + rs.top + rd.top - rd.bottom) / 2,
			   rd.right - rd.left, rd.bottom - rd.top, TRUE);
	}

	state = smalloc(sizeof(*state));
	state->generation_thread_exists = FALSE;
	state->collecting_entropy = FALSE;
	state->entropy = NULL;
	state->key_exists = FALSE;
	SetWindowLong(hwnd, GWL_USERDATA, (LONG) state);
	{
	    struct ctlpos cp, cp2;

	    /* Accelerators used: acglops1rb */

	    ctlposinit(&cp, hwnd, 10, 10, 10);
	    bartitle(&cp, "Public and private key generation for PuTTY",
		     IDC_TITLE);
	    beginbox(&cp, "Key", IDC_BOX_KEY);
	    cp2 = cp;
	    statictext(&cp2, "No key.", IDC_NOKEY);
	    cp2 = cp;
	    statictext(&cp2, "", IDC_GENERATING);
	    progressbar(&cp2, IDC_PROGRESS);
	    bigeditctrl(&cp,
			"&Public key for pasting into authorized_keys file:",
			IDC_PKSTATIC, IDC_KEYDISPLAY, 7);
	    SendDlgItemMessage(hwnd, IDC_KEYDISPLAY, EM_SETREADONLY, 1, 0);
	    staticedit(&cp, "Key fingerprint:", IDC_FPSTATIC,
		       IDC_FINGERPRINT, 75);
	    SendDlgItemMessage(hwnd, IDC_FINGERPRINT, EM_SETREADONLY, 1,
			       0);
	    staticedit(&cp, "Key &comment:", IDC_COMMENTSTATIC,
		       IDC_COMMENTEDIT, 75);
	    staticpassedit(&cp, "Key p&assphrase:", IDC_PASSPHRASE1STATIC,
			   IDC_PASSPHRASE1EDIT, 75);
	    staticpassedit(&cp, "C&onfirm passphrase:",
			   IDC_PASSPHRASE2STATIC, IDC_PASSPHRASE2EDIT, 75);
	    endbox(&cp);
	    beginbox(&cp, "Actions", IDC_BOX_ACTIONS);
	    staticbtn(&cp, "Generate a public/private key pair",
		      IDC_GENSTATIC, "&Generate", IDC_GENERATE);
	    staticbtn(&cp, "Load an existing private key file",
		      IDC_LOADSTATIC, "&Load", IDC_LOAD);
	    static2btn(&cp, "Save the generated key", IDC_SAVESTATIC,
		       "Save p&ublic key", IDC_SAVEPUB,
		       "&Save private key", IDC_SAVE);
	    endbox(&cp);
	    beginbox(&cp, "Parameters", IDC_BOX_PARAMS);
	    radioline(&cp, "Type of key to generate:", IDC_TYPESTATIC, 2,
		      "SSH&1 (RSA)", IDC_KEYSSH1,
		      "SSH2 &RSA", IDC_KEYSSH2RSA, 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);
	SetDlgItemInt(hwnd, IDC_BITS, DEFAULT_KEYSIZE, FALSE);

	/*
	 * Initially, hide the progress bar and the key display,
	 * and show the no-key display. Also disable the Save
	 * buttons, because with no key we obviously can't save
	 * anything.
	 */
	hidemany(hwnd, nokey_ids, FALSE);
	hidemany(hwnd, generating_ids, TRUE);
	hidemany(hwnd, gotkey_ids, TRUE);
	EnableWindow(GetDlgItem(hwnd, IDC_SAVE), 0);
	EnableWindow(GetDlgItem(hwnd, IDC_SAVEPUB), 0);

	return 1;
      case WM_MOUSEMOVE:
	state = (struct MainDlgState *) GetWindowLong(hwnd, GWL_USERDATA);
	if (state->collecting_entropy &&
	    state->entropy && state->entropy_got < state->entropy_required) {
	    state->entropy[state->entropy_got++] = lParam;
	    state->entropy[state->entropy_got++] = GetMessageTime();
	    SendDlgItemMessage(hwnd, IDC_PROGRESS, PBM_SETPOS,
			       state->entropy_got, 0);
	    if (state->entropy_got >= state->entropy_required) {
		struct rsa_key_thread_params *params;
		DWORD threadid;

		/*
		 * Seed the entropy pool
		 */
		random_add_heavynoise(state->entropy, state->entropy_size);
		memset(state->entropy, 0, state->entropy_size);
		sfree(state->entropy);
		state->collecting_entropy = FALSE;

		SetDlgItemText(hwnd, IDC_GENERATING, generating_msg);
		SendDlgItemMessage(hwnd, IDC_PROGRESS, PBM_SETRANGE, 0,
				   MAKELPARAM(0, PROGRESSRANGE));
		SendDlgItemMessage(hwnd, IDC_PROGRESS, PBM_SETPOS, 0, 0);

		params = smalloc(sizeof(*params));
		params->progressbar = GetDlgItem(hwnd, IDC_PROGRESS);
		params->dialog = hwnd;
		params->keysize = state->keysize;
		params->key = &state->key;

		if (!CreateThread(NULL, 0, generate_rsa_key_thread,
				  params, 0, &threadid)) {
		    MessageBox(hwnd, "Out of thread resources",
			       "Key generation error",
			       MB_OK | MB_ICONERROR);
		    sfree(params);
		} else {
		    state->generation_thread_exists = TRUE;
		}
	    }
	}
	break;
      case WM_COMMAND:
	switch (LOWORD(wParam)) {
	  case IDC_COMMENTEDIT:
	    if (HIWORD(wParam) == EN_CHANGE) {
		state = (struct MainDlgState *)
		    GetWindowLong(hwnd, GWL_USERDATA);
		if (state->key_exists) {
		    HWND editctl = GetDlgItem(hwnd, IDC_COMMENTEDIT);
		    int len = GetWindowTextLength(editctl);
		    if (*state->commentptr)
			sfree(*state->commentptr);
		    *state->commentptr = smalloc(len + 1);
		    GetWindowText(editctl, *state->commentptr, len + 1);
		    if (state->ssh2) {
			setupbigedit2(hwnd, IDC_KEYDISPLAY, IDC_PKSTATIC,
				      &state->ssh2key);
		    } else {
			setupbigedit1(hwnd, IDC_KEYDISPLAY, IDC_PKSTATIC,
				      &state->key);
		    }
		}
	    }
	    break;
	  case IDC_ABOUT:
	    EnableWindow(hwnd, 0);
	    DialogBox(hinst, MAKEINTRESOURCE(213), NULL, AboutProc);
	    EnableWindow(hwnd, 1);
	    SetActiveWindow(hwnd);
	    return 0;
	  case IDC_GENERATE:
	    state =
		(struct MainDlgState *) GetWindowLong(hwnd, GWL_USERDATA);
	    if (!state->generation_thread_exists) {
		BOOL ok;
		state->keysize = GetDlgItemInt(hwnd, IDC_BITS, &ok, FALSE);
		if (!ok)
		    state->keysize = DEFAULT_KEYSIZE;
		/* If we ever introduce a new key type, check it here! */
		state->ssh2 = !IsDlgButtonChecked(hwnd, IDC_KEYSSH1);
		if (state->keysize < 256) {
		    int ret = MessageBox(hwnd,
					 "PuTTYgen will not generate a key"
					 " smaller than 256 bits.\n"
					 "Key length reset to 256. Continue?",
					 "PuTTYgen Warning",
					 MB_ICONWARNING | MB_OKCANCEL);
		    if (ret != IDOK)
			break;
		    state->keysize = 256;
		    SetDlgItemInt(hwnd, IDC_BITS, 256, FALSE);
		}
		hidemany(hwnd, nokey_ids, TRUE);
		hidemany(hwnd, generating_ids, FALSE);
		hidemany(hwnd, gotkey_ids, TRUE);
		EnableWindow(GetDlgItem(hwnd, IDC_GENERATE), 0);
		EnableWindow(GetDlgItem(hwnd, IDC_LOAD), 0);
		EnableWindow(GetDlgItem(hwnd, IDC_SAVE), 0);
		EnableWindow(GetDlgItem(hwnd, IDC_SAVEPUB), 0);
		EnableWindow(GetDlgItem(hwnd, IDC_KEYSSH1), 0);
		EnableWindow(GetDlgItem(hwnd, IDC_KEYSSH2RSA), 0);
		EnableWindow(GetDlgItem(hwnd, IDC_BITS), 0);
		state->key_exists = FALSE;
		SetDlgItemText(hwnd, IDC_GENERATING, entropy_msg);
		state->collecting_entropy = TRUE;

		/*
		 * My brief statistical tests on mouse movements
		 * suggest that there are about 2.5 bits of
		 * randomness in the x position, 2.5 in the y
		 * position, and 1.7 in the message time, making
		 * 5.7 bits of unpredictability per mouse movement.
		 * However, other people have told me it's far less
		 * than that, so I'm going to be stupidly cautious
		 * and knock that down to a nice round 2. With this
		 * method, we require two words per mouse movement,
		 * so with 2 bits per mouse movement we expect 2
		 * bits every 2 words.
		 */
		state->entropy_required = (state->keysize / 2) * 2;
		state->entropy_got = 0;
		state->entropy_size = (state->entropy_required *
				       sizeof(*state->entropy));
		state->entropy = smalloc(state->entropy_size);

		SendDlgItemMessage(hwnd, IDC_PROGRESS, PBM_SETRANGE, 0,
				   MAKELPARAM(0, state->entropy_required));
		SendDlgItemMessage(hwnd, IDC_PROGRESS, PBM_SETPOS, 0, 0);
	    }
	    break;
	  case IDC_SAVE:
	    state =
		(struct MainDlgState *) GetWindowLong(hwnd, GWL_USERDATA);
	    if (state->key_exists) {
		char filename[FILENAME_MAX];
		char passphrase[PASSPHRASE_MAXLEN];
		char passphrase2[PASSPHRASE_MAXLEN];
		GetDlgItemText(hwnd, IDC_PASSPHRASE1EDIT,
			       passphrase, sizeof(passphrase));
		GetDlgItemText(hwnd, IDC_PASSPHRASE2EDIT,
			       passphrase2, sizeof(passphrase2));
		if (strcmp(passphrase, passphrase2)) {
		    MessageBox(hwnd,
			       "The two passphrases given do not match.",
			       "PuTTYgen Error", MB_OK | MB_ICONERROR);
		    break;
		}
		if (!*passphrase) {
		    int ret;
		    ret = MessageBox(hwnd,
				     "Are you sure you want to save this key\n"
				     "without a passphrase to protect it?",
				     "PuTTYgen Warning",
				     MB_YESNO | MB_ICONWARNING);
		    if (ret != IDYES)
			break;
		}
		if (prompt_keyfile(hwnd, "Save private key as:",
				   filename, 1)) {
		    int ret;
		    FILE *fp = fopen(filename, "r");
		    if (fp) {
			char buffer[FILENAME_MAX + 80];
			fclose(fp);
			sprintf(buffer, "Overwrite existing file\n%.*s?",
				FILENAME_MAX, filename);
			ret = MessageBox(hwnd, buffer, "PuTTYgen Warning",
					 MB_YESNO | MB_ICONWARNING);
			if (ret != IDYES)
			    break;
		    }
		    if (state->ssh2) {
			ret = ssh2_save_userkey(filename, &state->ssh2key,
						*passphrase ? passphrase :
						NULL);
		    } else {
			ret = saversakey(filename, &state->key,
					 *passphrase ? passphrase : NULL);
		    }
		    if (ret <= 0) {
			MessageBox(hwnd, "Unable to save key file",
				   "PuTTYgen Error", MB_OK | MB_ICONERROR);
		    }
		}
	    }
	    break;
	  case IDC_SAVEPUB:
	    state =
		(struct MainDlgState *) GetWindowLong(hwnd, GWL_USERDATA);
	    if (state->key_exists) {
		char filename[FILENAME_MAX];
		if (prompt_keyfile(hwnd, "Save public key as:",
				   filename, 1)) {
		    int ret;
		    FILE *fp = fopen(filename, "r");
		    if (fp) {
			char buffer[FILENAME_MAX + 80];
			fclose(fp);
			sprintf(buffer, "Overwrite existing file\n%.*s?",
				FILENAME_MAX, filename);
			ret = MessageBox(hwnd, buffer, "PuTTYgen Warning",
					 MB_YESNO | MB_ICONWARNING);
			if (ret != IDYES)
			    break;
		    }
		    if (state->ssh2) {
			ret = save_ssh2_pubkey(filename, &state->ssh2key);
		    } else {
			ret = save_ssh1_pubkey(filename, &state->key);
		    }
		    if (ret <= 0) {
			MessageBox(hwnd, "Unable to save key file",
				   "PuTTYgen Error", MB_OK | MB_ICONERROR);
		    }
		}
	    }
	    break;
	  case IDC_LOAD:
	    state =
		(struct MainDlgState *) GetWindowLong(hwnd, GWL_USERDATA);
	    if (!state->generation_thread_exists) {
		char filename[FILENAME_MAX];
		if (prompt_keyfile(hwnd, "Load private key:", filename, 0)) {
		    char passphrase[PASSPHRASE_MAXLEN];
		    int needs_pass;
		    int ver;
		    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.",
				   "PuTTYgen Error", MB_OK | MB_ICONERROR);
			break;
		    }

		    comment = NULL;
		    if (ver == 1)
			needs_pass = rsakey_encrypted(filename, &comment);
		    else
			needs_pass =
			    ssh2_userkey_encrypted(filename, &comment);
		    pps.passphrase = passphrase;
		    pps.comment = comment;
		    do {
			if (needs_pass) {
			    int dlgret;
			    dlgret = DialogBoxParam(hinst,
						    MAKEINTRESOURCE(210),
						    NULL, PassphraseProc,
						    (LPARAM) & pps);
			    if (!dlgret) {
				ret = -2;
				break;
			    }
			} else
			    *passphrase = '\0';
			if (ver == 1)
			    ret =
				loadrsakey(filename, &newkey1, passphrase);
			else {
			    newkey2 =
				ssh2_load_userkey(filename, passphrase);
			    if (newkey2 == SSH2_WRONG_PASSPHRASE)
				ret = -1;
			    else if (!newkey2)
				ret = 0;
			    else
				ret = 1;
			}
		    } while (ret == -1);
		    if (comment)
			sfree(comment);
		    if (ret == 0) {
			MessageBox(NULL, "Couldn't load private key.",
				   "PuTTYgen Error", MB_OK | MB_ICONERROR);
		    } else if (ret == 1) {
			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_BITS), 1);
			/*
			 * Now update the key controls with all the
			 * key data.
			 */
			{
			    SetDlgItemText(hwnd, IDC_PASSPHRASE1EDIT,
					   passphrase);
			    SetDlgItemText(hwnd, IDC_PASSPHRASE2EDIT,
					   passphrase);
			    if (ver == 1) {
				char buf[128];
				char *savecomment;

				state->ssh2 = FALSE;
				state->commentptr = &state->key.comment;
				state->key = newkey1;

				/*
				 * Set the key fingerprint.
				 */
				savecomment = state->key.comment;
				state->key.comment = NULL;
				rsa_fingerprint(buf, sizeof(buf),
						&state->key);
				state->key.comment = savecomment;

				SetDlgItemText(hwnd, IDC_FINGERPRINT, buf);
				/*
				 * Construct a decimal representation
				 * of the key, for pasting into
				 * .ssh/authorized_keys on a Unix box.
				 */
				setupbigedit1(hwnd, IDC_KEYDISPLAY,
					      IDC_PKSTATIC, &state->key);
			    } else {
				char *fp;
				char *savecomment;

				state->ssh2 = TRUE;
				state->commentptr =
				    &state->ssh2key.comment;
				state->ssh2key = *newkey2;	/* structure copy */
				sfree(newkey2);

				savecomment = state->ssh2key.comment;
				state->ssh2key.comment = NULL;
				fp =
				    state->ssh2key.alg->
				    fingerprint(state->ssh2key.data);
				state->ssh2key.comment = savecomment;

				SetDlgItemText(hwnd, IDC_FINGERPRINT, fp);
				sfree(fp);

				setupbigedit2(hwnd, IDC_KEYDISPLAY,
					      IDC_PKSTATIC, &state->ssh2key);
			    }
			    SetDlgItemText(hwnd, IDC_COMMENTEDIT,
					   *state->commentptr);
			}
			/*
			 * Finally, hide the progress bar and show
			 * the key data.
			 */
			hidemany(hwnd, nokey_ids, TRUE);
			hidemany(hwnd, generating_ids, TRUE);
			hidemany(hwnd, gotkey_ids, FALSE);
			state->key_exists = TRUE;
		    }
		}
	    }
	    break;
	}
	return 0;
      case WM_DONEKEY:
	state = (struct MainDlgState *) GetWindowLong(hwnd, GWL_USERDATA);
	state->generation_thread_exists = FALSE;
	state->key_exists = TRUE;
	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_BITS), 1);
	if (state->ssh2) {
	    state->ssh2key.data = &state->key;
	    state->ssh2key.alg = &ssh_rsa;
	    state->commentptr = &state->ssh2key.comment;
	} else {
	    state->commentptr = &state->key.comment;
	}
	/*
	 * Invent a comment for the key. We'll do this by including
	 * the date in it. This will be so horrifyingly ugly that
	 * the user will immediately want to change it, which is
	 * what we want :-)
	 */
	*state->commentptr = smalloc(30);
	{
	    time_t t;
	    struct tm *tm;
	    time(&t);
	    tm = localtime(&t);
	    strftime(*state->commentptr, 30, "rsa-key-%Y%m%d", tm);
	}

	/*
	 * Now update the key controls with all the key data.
	 */
	{
	    char *savecomment;
	    /*
	     * Blank passphrase, initially. This isn't dangerous,
	     * because we will warn (Are You Sure?) before allowing
	     * the user to save an unprotected private key.
	     */
	    SetDlgItemText(hwnd, IDC_PASSPHRASE1EDIT, "");
	    SetDlgItemText(hwnd, IDC_PASSPHRASE2EDIT, "");
	    /*
	     * Set the comment.
	     */
	    SetDlgItemText(hwnd, IDC_COMMENTEDIT, *state->commentptr);
	    /*
	     * Set the key fingerprint.
	     */
	    savecomment = *state->commentptr;
	    *state->commentptr = NULL;
	    if (state->ssh2) {
		char *fp;
		fp = state->ssh2key.alg->fingerprint(state->ssh2key.data);
		SetDlgItemText(hwnd, IDC_FINGERPRINT, fp);
		sfree(fp);
	    } else {
		char buf[128];
		rsa_fingerprint(buf, sizeof(buf), &state->key);
		SetDlgItemText(hwnd, IDC_FINGERPRINT, buf);
	    }
	    *state->commentptr = savecomment;
	    /*
	     * Construct a decimal representation of the key, for
	     * pasting into .ssh/authorized_keys or
	     * .ssh/authorized_keys2 on a Unix box.
	     */
	    if (state->ssh2) {
		setupbigedit2(hwnd, IDC_KEYDISPLAY,
			      IDC_PKSTATIC, &state->ssh2key);
	    } else {
		setupbigedit1(hwnd, IDC_KEYDISPLAY,
			      IDC_PKSTATIC, &state->key);
	    }
	}
	/*
	 * Finally, hide the progress bar and show the key data.
	 */
	hidemany(hwnd, nokey_ids, TRUE);
	hidemany(hwnd, generating_ids, TRUE);
	hidemany(hwnd, gotkey_ids, FALSE);
	break;
      case WM_CLOSE:
	state = (struct MainDlgState *) GetWindowLong(hwnd, GWL_USERDATA);
	sfree(state);
	EndDialog(hwnd, 1);
	return 0;
    }
    return 0;
}

int WINAPI WinMain(HINSTANCE inst, HINSTANCE prev, LPSTR cmdline, int show)
{
    InitCommonControls();
    hinst = inst;
    random_init();
    return DialogBox(hinst, MAKEINTRESOURCE(201), NULL,
		     MainDlgProc) != IDOK;
}