/[winpt]/trunk/Src/wptPassphraseCB.cpp
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Contents of /trunk/Src/wptPassphraseCB.cpp

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Revision 278 - (show annotations)
Mon Jan 15 22:02:04 2007 UTC (18 years, 1 month ago) by twoaday
File size: 13739 byte(s)
See ChangeLog.


1 /* wptPassphraseCB.cpp - GPGME Passphrase Callback
2 * Copyright (C) 2001, 2002-2006 Timo Schulz
3 * Copyright (C) 2005 g10 Code GmbH
4 *
5 * This file is part of WinPT.
6 *
7 * WinPT is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version 2
10 * of the License, or (at your option) any later version.
11 *
12 * WinPT is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * General Public License for more details.
16 */
17 #ifdef HAVE_CONFIG_H
18 #include <config.h>
19 #endif
20
21 #include <windows.h>
22 #include <ctype.h>
23
24 #include "resource.h"
25 #include "wptNLS.h"
26 #include "wptW32API.h"
27 #include "wptVersion.h"
28 #include "wptGPG.h"
29 #include "wptCommonCtl.h"
30 #include "wptContext.h"
31 #include "wptDlgs.h"
32 #include "wptErrors.h"
33 #include "wptTypes.h"
34 #include "wptKeylist.h"
35 #include "wptAgent.h"
36 #include "wptRegistry.h"
37 #include "wptUTF8.h"
38 #include "StringBuffer.h"
39
40
41 /* Return the control ID dependent on the mode (sign or decrypt). */
42 #define item_ctrl_id(cmd) \
43 ((cmd) == GPG_CMD_DECRYPT? IDC_DECRYPT_PWD : IDC_DECRYPT_SIGN_PWD)
44
45 #define item_ctrl_id2(cmd) \
46 ((cmd) == GPG_CMD_DECRYPT? IDC_DECRYPT_HIDE : IDC_DECRYPT_SIGN_HIDE)
47
48 const char* get_symkey_algo (int algo);
49 void ListBox_AddString_utf8 (HWND lb, const char *txt);
50
51
52 /* Overwrite passphrase and free memory. */
53 static void
54 burn_passphrase (char **pwd)
55 {
56 char *pass = *pwd;
57
58 wipememory (pass, strlen (pass));
59 delete []pass;
60 *pwd = NULL;
61 }
62
63
64 /* Dialog procedure for the passphrase callback. */
65 static BOOL CALLBACK
66 passphrase_callback_proc (HWND dlg, UINT msg, WPARAM wparam, LPARAM lparam)
67 {
68 static passphrase_cb_s *c;
69 gpgme_decrypt_result_t res=NULL;
70 gpgme_sign_result_t res_sig=NULL;
71 gpgme_recipient_t recip=NULL, r;
72 winpt_key_s key;
73 void *item;
74 int n;
75
76 switch (msg) {
77 case WM_ACTIVATE:
78 safe_edit_control_init (dlg, item_ctrl_id (c->gpg_cmd));
79 break;
80
81 case WM_DESTROY:
82 safe_edit_control_free (dlg, item_ctrl_id (c->gpg_cmd));
83 break;
84
85 case WM_INITDIALOG:
86 c = (passphrase_cb_s *)lparam;
87 if (!c)
88 BUG (0);
89 SetDlgItemText (dlg, IDCANCEL, _("&Cancel"));
90 SetWindowText (dlg, c->title);
91 if (c->gpg_cmd == GPG_CMD_DECRYPT) {
92 SetDlgItemText (dlg, IDC_DECRYPT_HIDE, _("&Hide Typing"));
93 SetDlgItemText (dlg, IDC_DECRYPT_LISTINF,
94 _("Encrypted with the following public key(s)"));
95 CheckDlgButton (dlg, IDC_DECRYPT_HIDE, BST_CHECKED);
96 }
97 else if (c->gpg_cmd == GPG_CMD_SIGN) {
98 SetDlgItemText (dlg, IDC_DECRYPT_SIGN_HIDE, _("&Hide Typing"));
99 CheckDlgButton (dlg, IDC_DECRYPT_SIGN_HIDE, BST_CHECKED);
100 }
101 /* Because it depends on the order the keys are stored in the
102 keyring whether res->recipients is complete or not, we also
103 support that the recipients were externally extracted and then
104 we use this list. */
105 if (c->recipients)
106 recip = c->recipients; /* recipients were already extracted. */
107 else {
108 res = gpgme_op_decrypt_result (c->gpg);
109 if (res && res->recipients)
110 recip = res->recipients;
111 }
112 if (recip != NULL && c->gpg_cmd == GPG_CMD_DECRYPT) {
113 StringBuffer inf;
114
115 for (r = recip; r; r = r->next) {
116 memset (&key, 0, sizeof (key));
117 if (!winpt_get_pubkey (r->keyid, &key)) {
118 gpgme_user_id_t u = key.ctx->uids;
119
120 inf = (u->name? u->name : _("Invalid User ID"));
121 if (u->email != NULL && strlen (u->email) > 1)
122 inf = inf + " <" + u->email + ">";
123 inf = inf + " (" + get_key_pubalgo (r->pubkey_algo);
124 inf = inf + ", 0x" + (r->keyid+8) + ")";
125 }
126 else {
127 inf = _("Unknown key ID");
128 inf = inf + " (" + get_key_pubalgo (r->pubkey_algo);
129 inf = inf + ", 0x" + (r->keyid+8) + ")";
130 }
131 ListBox_AddString_utf8 (GetDlgItem (dlg, IDC_DECRYPT_LIST),
132 inf.getBuffer ());
133 winpt_release_pubkey (&key);
134 }
135 }
136 else if (c->gpg_cmd == GPG_CMD_DECRYPT)
137 EnableWindow (GetDlgItem (dlg, IDC_DECRYPT_LIST), FALSE);
138 SetDlgItemText (dlg, c->gpg_cmd == GPG_CMD_DECRYPT?
139 IDC_DECRYPT_PWDINFO : IDC_DECRYPT_SIGN_PWDINFO,
140 c->bad_pwd? _("Bad passphrase; Enter passphrase again") :
141 _("Please enter your passphrase"));
142 if (c->gpg_cmd == GPG_CMD_DECRYPT) {
143 SetFocus (GetDlgItem (dlg, IDC_DECRYPT_PWD));
144 if (res && !res->recipients) {
145 StringBuffer sinf;
146
147 sinf = _("Symmetric encryption.");
148 sinf = sinf + "\n" + get_symkey_algo (c->sym.sym_algo);
149 sinf = sinf + " " + _("encrypted data.");
150 SetDlgItemText (dlg, IDC_DECRYPT_MSG, sinf.getBuffer ());
151 }
152 else
153 SetDlgItemText (dlg, IDC_DECRYPT_MSG, c->info);
154 }
155 else {
156 SetFocus (GetDlgItem (dlg, IDC_DECRYPT_SIGN_PWD));
157 SetDlgItemText (dlg, IDC_DECRYPT_SIGN_MSG, c->info);
158 }
159 center_window (dlg, NULL);
160 SetForegroundWindow (dlg);
161 return FALSE;
162
163 case WM_COMMAND:
164 switch (HIWORD (wparam)) {
165 case BN_CLICKED:
166 if (LOWORD (wparam) == IDC_DECRYPT_HIDE
167 || LOWORD (wparam) == IDC_DECRYPT_SIGN_HIDE) {
168 HWND hwnd;
169 int hide = IsDlgButtonChecked (dlg, item_ctrl_id2 (c->gpg_cmd));
170 hwnd = GetDlgItem (dlg, item_ctrl_id (c->gpg_cmd));
171 SendMessage (hwnd, EM_SETPASSWORDCHAR, hide? '*' : 0, 0);
172 SetFocus (hwnd);
173 }
174 }
175
176 switch (LOWORD (wparam)) {
177 case IDOK:
178 /* XXX: the item is even cached when the passphrase is not
179 correct, which means that the user needs to delete all
180 cached entries to continue. */
181 if (c->pwd)
182 burn_passphrase (&c->pwd);
183 n = item_get_text_length (dlg, item_ctrl_id (c->gpg_cmd));
184 if (!n) {
185 c->pwd = new char[2];
186 if (!c->pwd)
187 BUG (NULL);
188 strcpy (c->pwd, "");
189 }
190 else {
191 char *p = new char[n+2];
192 if (!p)
193 BUG (NULL);
194 /* Get the passphrase and convert it utf8.
195 This does not just the us-ascii charset. */
196 SafeGetDlgItemText (dlg, item_ctrl_id (c->gpg_cmd), p, n+1);
197 c->pwd = native_to_utf8 (p);
198 sfree_if_alloc (p);
199 }
200 res = gpgme_op_decrypt_result (c->gpg);
201 if (!res)
202 res_sig = gpgme_op_sign_result (c->gpg);
203 if (!c->is_card && reg_prefs.cache_time > 0 &&
204 (res || res_sig)) {
205 if (agent_get_cache (c->keyid, &item))
206 agent_unlock_cache_entry (&item);
207 else
208 agent_put_cache (c->keyid, c->pwd, reg_prefs.cache_time);
209 }
210 c->cancel = 0;
211 EndDialog (dlg, TRUE);
212 return TRUE;
213
214 case IDCANCEL:
215 SetDlgItemText (dlg, item_ctrl_id (c->gpg_cmd), "");
216 c->cancel = 1;
217 EndDialog (dlg, FALSE);
218 return TRUE;
219 }
220 break;
221 }
222
223 return FALSE;
224 }
225
226
227 /* Extract the main keyid from @pass_info.
228 Return value: long main keyid or NULL for an error. */
229 static const char*
230 parse_gpg_keyid (const char *pass_info)
231 {
232 static char keyid[16+1];
233
234 /* XXX: check for leading alpha-chars? */
235 if (strlen (pass_info) < 16) {
236 log_debug ("parse_gpg_keyid: error '%s'\r\n", pass_info);
237 return NULL;
238 }
239 /* the format of the desc buffer looks like this:
240 request_keyid[16] main_keyid[16] keytype[1] keylength[4]
241 we use the main keyid to use only one cache entry. */
242 strncpy (keyid, pass_info+17, 16);
243 keyid[16] = 0;
244 return keyid;
245 }
246
247
248 /* Parse the information in @uid_hint and @pass_info to generate
249 a input message for the user in @desc. */
250 static int
251 parse_gpg_description (const char *uid_hint, const char *pass_info,
252 char *desc, int size)
253 {
254 gpgme_pubkey_algo_t algo;
255 char usedkey[16+1];
256 char mainkey[16+1];
257 char *p, *uid;
258 int n=0;
259
260 algo = (gpgme_pubkey_algo_t)0;
261 /* Each uid_hint contains a long key-ID so it is at least 16 bytes. */
262 if (strlen (uid_hint) < 17) {
263 *desc = 0;
264 log_debug ("parse_gpg_description: error '%s'\r\n", uid_hint);
265 return -1;
266 }
267
268 while (p = strsep ((char**)&pass_info, " ")) {
269 switch (n++) {
270 case 0: strncpy (mainkey, p, 16); mainkey[16] = 0; break;
271 case 1: strncpy (usedkey, p, 16); usedkey[16] = 0; break;
272 case 2: algo = (gpgme_pubkey_algo_t)atol (p); break;
273 }
274 }
275 uid_hint += 16; /* skip keyid */
276 uid_hint += 1; /* space */
277
278 uid = utf8_to_native (uid_hint);
279 if (strcmp (usedkey, mainkey))
280 _snprintf (desc, size-1,
281 _("You need a passphrase to unlock the secret key for user:\n"
282 "\"%s\"\n"
283 "%s key, ID 0x%s (main key ID 0x%s)\n"),
284 uid, get_key_pubalgo (algo), usedkey+8, mainkey+8);
285 else if (!strcmp (usedkey, mainkey))
286 _snprintf (desc, size-1,
287 _("You need a passphrase to unlock the secret key for user:\n"
288 "\"%s\"\n"
289 "%s key, ID 0x%s\n"),
290 uid, get_key_pubalgo (algo), usedkey+8);
291 safe_free (uid);
292 return 0;
293 }
294
295
296 /* Extract the serial number from the card ID @id and return it. */
297 const char*
298 extract_serial_no (const char *id)
299 {
300 static char buf[8];
301 char *p;
302
303 p = strchr (id, '/');
304 if (!p) {
305 log_debug ("extract_serial_no: error '%s'\r\n", id);
306 return "";
307 }
308 memset (buf, 0, sizeof (buf));
309 strncpy (buf, id+(p-id)-6, 6);
310 return buf;
311 }
312
313
314 /* Passphrase callback with the ability to support caching. */
315 gpgme_error_t
316 passphrase_cb (void *hook, const char *uid_hint,
317 const char *passphrase_info,
318 int prev_was_bad, int fd)
319 {
320 passphrase_cb_s *c = (passphrase_cb_s*)hook;
321 HANDLE hd = (HANDLE)fd;
322 void *item;
323 const char *keyid=NULL, *pass;
324 DWORD n;
325 int rc = 0;
326
327 if (!c) {
328 log_debug ("passphrase_cb: error no valid callback\r\n");
329 return gpg_error (GPG_ERR_INV_ARG);
330 }
331 c->bad_pwd = prev_was_bad? 1 : 0;
332 if (prev_was_bad && !c->cancel) {
333 if (c->pwd)
334 burn_passphrase (&c->pwd);
335 agent_del_cache (c->keyid);
336 c->pwd_init = 1;
337 }
338
339 if (passphrase_info) {
340 if (strlen (passphrase_info) < 16 &&
341 !strstr (passphrase_info, "OPENPGP")) {
342 /* assume symetric encryption. */
343 int pos=2;
344 c->sym.sym_algo = atoi (passphrase_info);
345 if (c->sym.sym_algo > 9)
346 pos++;
347 /* XXX: be more strict. */
348 c->sym.s2k_mode = atoi (passphrase_info+pos);
349 c->sym.s2k_hash = atoi (passphrase_info+pos+2);
350 }
351
352 keyid = parse_gpg_keyid (passphrase_info);
353 pass = agent_get_cache (keyid+8, &item);
354 if (pass) {
355 agent_unlock_cache_entry (&item);
356 c->pwd_init = 0;
357 if (!WriteFile (hd, pass, strlen (pass), &n, NULL))
358 log_debug ("passphrase_cb: WriteFile() failed ec=%d\n", w32_errno);
359 if (!WriteFile (hd, "\n", 1, &n, NULL))
360 log_debug ("passphrase_cb: WriteFile() failed ec=%d\n", w32_errno);
361 return 0;
362 }
363 }
364
365 if (c->pwd_init) {
366 if (keyid && strlen (keyid) == 16)
367 strcpy (c->keyid, keyid+8);
368
369 /* if @passphrase_info contains 'OPENPGP' we assume a smart card
370 has been used. */
371 if (strstr (passphrase_info, "OPENPGP")) {
372 const char *s=passphrase_info;
373 while (s && *s && *s != 'D')
374 s++;
375 _snprintf (c->info, sizeof (c->info)-1,
376 _("Please enter the PIN to unlock your secret card key\n"
377 "Card: %s"), extract_serial_no (s));
378 c->is_card = 1;
379 }
380 else if (uid_hint)
381 parse_gpg_description (uid_hint, passphrase_info,
382 c->info, sizeof (c->info) - 1);
383 if (c->gpg_cmd == GPG_CMD_DECRYPT) {
384 rc = DialogBoxParam (glob_hinst, (LPCSTR)IDD_WINPT_DECRYPT,
385 (HWND)c->hwnd, passphrase_callback_proc,
386 (LPARAM)c);
387 }
388 else if (c->gpg_cmd == GPG_CMD_SIGN) {
389 rc = DialogBoxParam (glob_hinst, (LPCSTR)IDD_WINPT_DECRYPT_SIGN,
390 (HWND)c->hwnd, passphrase_callback_proc,
391 (LPARAM)c);
392 }
393 if (rc == -1) {
394 if (!WriteFile (hd, "\n", 1, &n, NULL))
395 log_debug ("passphrase_cb: WriteFile() failed ec=%d\n", w32_errno);
396 log_debug ("passphrase_cb: could not create dialog box\n");
397 return 0;
398 }
399 c->pwd_init = 0;
400 }
401 if (c->cancel || !c->pwd) {
402 if (!WriteFile (hd, "\n", 1, &n, NULL))
403 log_debug ("passphrase_cb: WriteFile() failed ec=%d\n", w32_errno);
404 return 0;
405 }
406
407 if (!WriteFile (hd, c->pwd, strlen (c->pwd), &n, NULL))
408 log_debug ("passphrase_cb: WriteFile() failed ec=%d\n", w32_errno);
409 if (!WriteFile (hd, "\n", 1, &n, NULL))
410 log_debug ("passphrase_cb: WriteFile() failed ec=%d\n", w32_errno);
411 return 0;
412 }
413
414
415 /* Initialize the given passphrase callback @cb with the
416 used gpgme context @ctx, the command @cmd and a title
417 @title for the dialog. */
418 void
419 set_gpg_passphrase_cb (passphrase_cb_s *cb, gpgme_ctx_t ctx,
420 int cmd, HWND hwnd, const char *title)
421 {
422 memset (cb, 0, sizeof *cb);
423 cb->gpg_cmd = cmd;
424 cb->bad_pwd = 0;
425 cb->is_card = 0;
426 cb->cancel = 0;
427 cb->hwnd = hwnd;
428 cb->pwd_init = 1;
429 free_if_alloc (cb->title);
430 cb->title = m_strdup (title);
431 gpgme_set_passphrase_cb (ctx, passphrase_cb, cb);
432 cb->gpg = ctx;
433 }
434
435
436 /* Release the gpg recipient list. */
437 void
438 release_gpg_recipients (gpgme_recipient_t *recipients)
439 {
440 gpgme_recipient_t r, n;
441
442 r = *recipients;
443 while (r != NULL) {
444 n = r->next;
445 safe_free (r->keyid);
446 safe_free (r);
447 r = n;
448 }
449 *recipients = NULL;
450 }
451
452
453
454 /* Release a passphrase callback @ctx. */
455 void
456 release_gpg_passphrase_cb (passphrase_cb_s *ctx)
457 {
458 if (!ctx)
459 return;
460 sfree_if_alloc (ctx->pwd);
461 free_if_alloc (ctx->title);
462 release_gpg_recipients (&ctx->recipients);
463 }
464
465
466 /* _Simple_ check to measure passphrase (@pass) quality.
467 Return value: 0 on success. */
468 int
469 check_passwd_quality (const char *pass, int strict)
470 {
471 int i, nd=0, nc=0, n;
472
473 /* A good passphrase should be at least 8 characters. */
474 n = strlen (pass);
475 if (n < 8)
476 return -1;
477
478 for (i=0; i < n; i++) {
479 if (isdigit (pass[i]))
480 nd++;
481 if (isalpha (pass[i]))
482 nc++;
483 }
484
485 /* Check that the passphrase contains letters and numbers. */
486 if (nd == n || nc == n)
487 return -1;
488
489 return 0;
490 }

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