trunk/Src/wptPassphraseCB.cpp

/* wptPassphraseCB.cpp - GPGME Passphrase Callback
 *      Copyright (C) 2001, 2002, 2003, 2005 Timo Schulz
 *      Copyright (C) 2005 g10 Code GmbH
 *
 * This file is part of WinPT.
 *
 * WinPT is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License 
 * as published by the Free Software Foundation; either version 2 
 * of the License, or (at your option) any later version.
 *  
 * WinPT is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License 
 * along with WinPT; if not, write to the Free Software Foundation, 
 * Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 
 */

#include <windows.h>
#include <ctype.h>

#include "../resource.h"
#include "wptNLS.h"
#include "wptW32API.h"
#include "wptVersion.h"
#include "wptGPG.h"
#include "wptCommonCtl.h"
#include "wptContext.h"
#include "wptDlgs.h"
#include "wptUTF8.h"
#include "wptErrors.h"
#include "wptTypes.h"
#include "wptKeyList.h"
#include "wptAgent.h"
#include "wptRegistry.h"

const char* get_symkey_algo (int algo);

#define item_ctrl_id( cmd ) \
    ((cmd) == GPG_CMD_DECRYPT? IDC_DECRYPT_PWD : IDC_DECRYPT_SIGN_PWD)

#define item_ctrl_id2(cmd) \
    ((cmd) == GPG_CMD_DECRYPT? IDC_DECRYPT_HIDE : IDC_DECRYPT_SIGN_HIDE)


/* Overwrite passphrase and free memory. */
static void
burn_passphrase (char **pwd)
{
    char *pass = *pwd;
    wipememory (pass, strlen (pass));
    delete []pass;
    *pwd = NULL;
}


/* Dialog procedure for the passphrase callback. */
static BOOL CALLBACK
passphrase_callback_proc (HWND dlg, UINT msg, WPARAM wparam, LPARAM lparam)
{    
    static passphrase_cb_s * c;
    gpgme_decrypt_result_t res;
    gpgme_sign_result_t res_sig;
    gpgme_key_t key;
    gpgme_recipient_t recip, r;
    void *ctx = NULL, *item;
    const char *id;
    char *info;
    int n;

    switch (msg) {
    case WM_INITDIALOG:
        c = (passphrase_cb_s *)lparam;
        if (!c)
            BUG (0);
        SetWindowText (dlg, c->title);
        if (c->gpg_cmd == GPG_CMD_DECRYPT) {
            SetDlgItemText (dlg, IDC_DECRYPT_LISTINF,
                            _("Encrypted with the following public key(s)"));
            CheckDlgButton (dlg, IDC_DECRYPT_HIDE, BST_CHECKED);
        }
        else if (c->gpg_cmd == GPG_CMD_SIGN)
            CheckDlgButton (dlg, IDC_DECRYPT_SIGN_HIDE, BST_CHECKED);
        if (c->recipients)
            recip = c->recipients; /* recipients were already extracted. */
        else {
            /* XXX: not all ENCRYPT_TO entries are listed here. */
            res = gpgme_op_decrypt_result (c->gpg);
            if (res && res->recipients)
                recip = res->recipients;
        }
        if (recip != NULL && c->gpg_cmd == GPG_CMD_DECRYPT) {
            for (r = res->recipients; r; r = r->next) {
                get_pubkey (r->keyid, &key);
                if (key) {
                    char *uid;
                    id = key->uids->name;
                    if (!id)
                        id = _("Invalid User ID");
                    uid = utf8_to_wincp (id, strlen (id));
                    info = new char [32+strlen (uid)+1 + 4 + strlen (r->keyid)+1
                                     + strlen (key->uids->email)+1];
                    if (!info)
                        BUG (NULL);
                    sprintf (info, "%s <%s> (%s, 0x%s)", uid, key->uids->email,
                             get_key_pubalgo (r->pubkey_algo), r->keyid+8);
                    free (uid);
                    
                }
                else {
                    info = new char [32 + strlen (r->keyid)+1 + 4];
                    if (!info)
                        BUG (NULL);
                    sprintf (info, _("Unknown key ID (%s, 0x%s)"), 
                             get_key_pubalgo (r->pubkey_algo), r->keyid+8);
                }
                listbox_add_string (GetDlgItem (dlg, IDC_DECRYPT_LIST), info);
                free_if_alloc (info);
            }
        }
        else if (c->gpg_cmd == GPG_CMD_DECRYPT)
            EnableWindow (GetDlgItem (dlg, IDC_DECRYPT_LIST), FALSE);
        SetDlgItemText (dlg, c->gpg_cmd == GPG_CMD_DECRYPT?
                        IDC_DECRYPT_PWDINFO : IDC_DECRYPT_SIGN_PWDINFO,
                        c->bad_pwd? _("Bad passphrase; Enter passphrase again") :
                        _("Please enter your passphrase"));
        if (c->gpg_cmd == GPG_CMD_DECRYPT) {
            SetFocus (GetDlgItem (dlg, IDC_DECRYPT_PWD));
            if (res && !res->recipients) {
                const char *s = _("Symmetric encryption.\n"
                                  "%s encrypted data.");
                const char *alg = get_symkey_algo (c->sym.sym_algo);
                info = new char[strlen (s) + strlen (alg) + 2];
                if (!info)
                    BUG (NULL);
                sprintf (info, s, alg);
                SetDlgItemText (dlg, IDC_DECRYPT_MSG, info);
                free_if_alloc (info);
            }
            else
                SetDlgItemText (dlg, IDC_DECRYPT_MSG, c->info);
        }
        else {
            SetFocus( GetDlgItem (dlg, IDC_DECRYPT_SIGN_PWD));
            SetDlgItemText (dlg, IDC_DECRYPT_SIGN_MSG, c->info);
        }
        center_window (dlg, NULL);
        SetForegroundWindow (dlg);
        set_active_window (dlg);
        return FALSE;

        case WM_SYSCOMMAND:
            if (LOWORD (wparam) == SC_CLOSE) {
                SetDlgItemText (dlg, item_ctrl_id (c->gpg_cmd), "");
                c->cancel = 1;
                EndDialog (dlg, TRUE);
            }
            break;

        case WM_COMMAND:
            switch (HIWORD (wparam)) {
            case BN_CLICKED:
                if  (LOWORD (wparam) == IDC_DECRYPT_HIDE
                    || LOWORD (wparam) == IDC_DECRYPT_SIGN_HIDE) {
                    HWND hwnd;
                    int hide = IsDlgButtonChecked (dlg, item_ctrl_id2 (c->gpg_cmd));
                    hwnd = GetDlgItem (dlg, item_ctrl_id (c->gpg_cmd));
                    SendMessage (hwnd, EM_SETPASSWORDCHAR, hide? '*' : 0, 0);
                    SetFocus (hwnd);
                }
            }

            switch (LOWORD (wparam)) {
            case IDOK:  
                /* XXX: the item is even cached when the passphrase is not
                        correct, which means that the user needs to delete all
                        cached entries to continue. */
                if (c->pwd)
                    burn_passphrase (&c->pwd);
                n = item_get_text_length (dlg, item_ctrl_id (c->gpg_cmd));
                if (!n) {
                    c->pwd = new char[2];
                    if (!c->pwd)
                        BUG (NULL);
                    strcpy (c->pwd, "");
                }
                else {
                    c->pwd = new char[n+2];
                    if (!c->pwd)
                        BUG (NULL);
                    GetDlgItemText (dlg, item_ctrl_id (c->gpg_cmd), c->pwd, n+1);
                }
                res = gpgme_op_decrypt_result (c->gpg);
                if (!res)
                    res_sig = gpgme_op_sign_result (c->gpg);
                if (reg_prefs.cache_time > 0 && !c->is_card && 
                    ((res && res->recipients) || (res_sig && res_sig->signatures))) {
                    if (agent_get_cache (c->keyid, &item))
                        agent_unlock_cache_entry (&item);
                    else
                        agent_put_cache (c->keyid, c->pwd, reg_prefs.cache_time);
                }
                c->cancel = 0;
                EndDialog (dlg, TRUE);
                return TRUE;
                
            case IDCANCEL:
                SetDlgItemText (dlg, item_ctrl_id (c->gpg_cmd), "");
                c->cancel = 1;
                EndDialog (dlg, FALSE);
                return FALSE;
            }
            break;
    }
    
    return FALSE;
}


/* Extract the main keyid from @pass_info.
   Return value: long main keyid or NULL for an error. */
static const char*
parse_gpg_keyid (const char *pass_info)
{
    static char keyid[16+1];
    
    /* XXX: check for leading alpha-chars? */
    if (strlen (pass_info) < 16)
        return NULL;
    /* the format of the desc buffer looks like this:
       request_keyid[16] main_keyid[16] keytype[1] keylength[4]
       we use the main keyid to use only one cache entry. */
    strncpy (keyid, pass_info+17, 16);
    keyid[16] = 0;
    return keyid;
}


/* Parse the information in @uid_hint and @pass_info to generate
   a input message for the user in @desc. */
static int
parse_gpg_description (const char *uid_hint, const char *pass_info,
                       char *desc, int size)
{
    gpgme_pubkey_algo_t algo;
    char usedkey[16+1];
    char mainkey[16+1];
    char *uid, *p;
    int n=0;

    /* Each uid_hint contains a long key-ID so it is at least 16 bytes. */
    if (strlen (uid_hint) < 17) {
        *desc = 0;
        return -1;
    }

    while (p = strsep ((char**)&pass_info, " ")) {
        switch (n++) {
        case 0: strncpy (mainkey, p, 16); mainkey[16] = 0; break;
        case 1: strncpy (usedkey, p, 16); usedkey[16] = 0; break;
        case 2: algo = (gpgme_pubkey_algo_t)atol (p); break;
        }
    }
    uid_hint += 16; /* skip keyid */
    uid_hint += 1;  /* space */

    uid = utf8_to_wincp (uid_hint, strlen (uid_hint));

    if (strcmp (usedkey, mainkey))
        _snprintf (desc, size-1, 
                   _("You need a passphrase to unlock the secret key for\n"
                     "user: \"%s\"\n"
                     "%s key, ID %s (main key ID %s)\n"),
                   uid, get_key_pubalgo (algo), usedkey+8, mainkey+8);
    else if (!strcmp (usedkey, mainkey))
        _snprintf (desc, size-1,
                   _("You need a passphrase to unlock the secret key for\n"
                     "user: \"%s\"\n"
                     "%s key, ID %s\n"),
                     uid, get_key_pubalgo (algo), usedkey+8);
    free (uid);
    return 0;
}


/* Extract the serial number from the card ID @id and return it. */
const char*
extract_serial_no (const char *id)
{
    static char buf[8];
    char *p;

    p = strchr (id, '/');
    if (!p)
        return NULL;
    strncpy (buf, id+(p-id)-6, 6);
    return buf;
}


/* Passphrase callback with the ability to support caching. */
gpgme_error_t
passphrase_cb (void *hook, const char *uid_hint,
               const char *passphrase_info,
               int prev_was_bad, int fd)
{
    passphrase_cb_s *c = (passphrase_cb_s*)hook;
    HANDLE hd = (HANDLE)fd;
    void *item;
    const char *keyid, *pass;
    DWORD n;
    int rc;

    if (!c)
        return gpg_error (GPG_ERR_INV_ARG);
    c->bad_pwd = prev_was_bad? 1 : 0;
    if (prev_was_bad && !c->cancel) {
        if (c->pwd)
            burn_passphrase (&c->pwd);
        agent_del_cache (c->keyid);
        c->pwd_init = 1;
    }

    if (passphrase_info) {
        if (strlen (passphrase_info) < 16 && 
            !strstr (passphrase_info, "OPENPGP")) {
            /* assume symetric encryption. */
            int n=2;
            c->sym.sym_algo = atoi (passphrase_info);
            if (c->sym.sym_algo > 9)
                n++;
            /* XXX: be more strict. */
            c->sym.s2k_mode = atoi (passphrase_info+n);
            c->sym.s2k_hash = atoi (passphrase_info+n+2);
        }

        keyid = parse_gpg_keyid (passphrase_info);
        pass = agent_get_cache (keyid+8, &item);
        if (pass) {
            agent_unlock_cache_entry (&item);
            c->pwd_init = 0;
            if (!WriteFile (hd, pass, strlen (pass), &n, NULL))
                log_debug ("passphrase_cb: WriteFile() failed ec=%d\n", w32_errno);
            if (!WriteFile (hd, "\n", 1, &n, NULL))
                log_debug ("passphrase_cb: WriteFile() failed ec=%d\n", w32_errno);
            return 0;
        }
    }

    if (c->pwd_init) {
        if (keyid && strlen (keyid) == 16)
            strcpy (c->keyid, keyid+8);

        /* if @passphrase_info contains 'OPENPGP' we assume a smart card
            has been used. */
        if (strstr (passphrase_info, "OPENPGP")) {
            const char *s=passphrase_info;
            while (s && *s && *s != 'D')
                s++;
            _snprintf (c->info, sizeof c->info-1,
                       _("Please enter the PIN to unlock your secret card key\n"
                         "Card: %s"), extract_serial_no (s));
            c->is_card = 1;
        }
        else if (uid_hint)
            parse_gpg_description (uid_hint, passphrase_info, 
                                   c->info, sizeof c->info - 1);
        if (c->gpg_cmd == GPG_CMD_DECRYPT) {
            rc = DialogBoxParam (glob_hinst, (LPCSTR)IDD_WINPT_DECRYPT,
                                 (HWND)c->hwnd, passphrase_callback_proc,
                                 (LPARAM)c);
        }
        else if (c->gpg_cmd == GPG_CMD_SIGN) {
            rc = DialogBoxParam (glob_hinst, (LPCSTR)IDD_WINPT_DECRYPT_SIGN,
                                 (HWND)c->hwnd, passphrase_callback_proc,
                                 (LPARAM)c);
        }
        if (rc == -1) {
            if (!WriteFile (hd, "\n", 1, &n, NULL))
                log_debug ("passphrase_cb: WriteFile() failed ec=%d\n", w32_errno);
            return 0;
        }
        c->pwd_init = 0;
    }
    if (c->cancel) {
        if (!WriteFile (hd, "\n", 1, &n, NULL))
            log_debug ("passphrase_cb: WriteFile() failed ec=%d\n", w32_errno);
        return 0;
    }

    WriteFile (hd, c->pwd, strlen (c->pwd), &n, NULL);
    WriteFile (hd, "\n", 1, &n, NULL);
    return 0;
}


/* Initialize the given passphrase callback @cb with the
   used gpgme context @ctx, the command @cmd and a title
   @title for the dialog. */
void
set_gpg_passphrase_cb (passphrase_cb_s *cb, gpgme_ctx_t ctx, 
                       int cmd, HWND hwnd, const char *title)
{
    memset (cb, 0, sizeof *cb);
    cb->gpg_cmd = cmd;
    cb->bad_pwd = 0;
    cb->is_card = 0;
    cb->cancel = 0;
    cb->hwnd = hwnd;
    cb->pwd_init = 1;
    free_if_alloc (cb->title);
    cb->title = m_strdup (title);
    if (!cb->title)
        BUG (NULL);
    gpgme_set_passphrase_cb (ctx, passphrase_cb, cb);
    cb->gpg = ctx;
}


/* Release a passphrase callback @ctx. */
void
release_gpg_passphrase_cb (passphrase_cb_s *ctx)
{
    gpgme_recipient_t r, n;

    if (!ctx)
        return;
    sfree_if_alloc (ctx->pwd);
    free_if_alloc (ctx->title);
    r = ctx->recipients;
    while (r) {
        n = r->next;
        safe_free (r->keyid);
        safe_free (r);
        r = n;
    }
}


/* Simple check to measure passphrase (@pass) quality.
   Return value: 0 on success. */
int
check_passwd_quality (const char *pass, int strict)
{
    int i, nd=0, nc=0, n;

    n = strlen (pass);
    if (n < 8)
        return -1;

    for (i=0; i < n; i++) {
        if (isdigit (pass[i])) 
            nd++;
        if (isalpha (pass[i])) 
            nc++;
    }

    /* check that the passphrase contains letters and numbers. */
    if (nd == n || nc == n)
        return -1;

    return 0;
}
1	/* wptPassphraseCB.cpp - GPGME Passphrase Callback
2	* Copyright (C) 2001, 2002, 2003, 2005 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	* You should have received a copy of the GNU General Public License
18	* along with WinPT; if not, write to the Free Software Foundation,
19	* Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20	*/
21
22	#include <windows.h>
23	#include <ctype.h>
24
25	#include "../resource.h"
26	#include "wptNLS.h"
27	#include "wptW32API.h"
28	#include "wptVersion.h"
29	#include "wptGPG.h"
30	#include "wptCommonCtl.h"
31	#include "wptContext.h"
32	#include "wptDlgs.h"
33	#include "wptUTF8.h"
34	#include "wptErrors.h"
35	#include "wptTypes.h"
36	#include "wptKeyList.h"
37	#include "wptAgent.h"
38	#include "wptRegistry.h"
39
40	const char* get_symkey_algo (int algo);
41
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
49	/* Overwrite passphrase and free memory. */
50	static void
51	burn_passphrase (char **pwd)
52	{
53	char pass = pwd;
54	wipememory (pass, strlen (pass));
55	delete []pass;
56	*pwd = NULL;
57	}
58
59
60	/* Dialog procedure for the passphrase callback. */
61	static BOOL CALLBACK
62	passphrase_callback_proc (HWND dlg, UINT msg, WPARAM wparam, LPARAM lparam)
63	{
64	static passphrase_cb_s * c;
65	gpgme_decrypt_result_t res;
66	gpgme_sign_result_t res_sig;
67	gpgme_key_t key;
68	gpgme_recipient_t recip, r;
69	void ctx = NULL, item;
70	const char *id;
71	char *info;
72	int n;
73
74	switch (msg) {
75	case WM_INITDIALOG:
76	c = (passphrase_cb_s *)lparam;
77	if (!c)
78	BUG (0);
79	SetWindowText (dlg, c->title);
80	if (c->gpg_cmd == GPG_CMD_DECRYPT) {
81	SetDlgItemText (dlg, IDC_DECRYPT_LISTINF,
82	_("Encrypted with the following public key(s)"));
83	CheckDlgButton (dlg, IDC_DECRYPT_HIDE, BST_CHECKED);
84	}
85	else if (c->gpg_cmd == GPG_CMD_SIGN)
86	CheckDlgButton (dlg, IDC_DECRYPT_SIGN_HIDE, BST_CHECKED);
87	if (c->recipients)
88	recip = c->recipients; /* recipients were already extracted. */
89	else {
90	/* XXX: not all ENCRYPT_TO entries are listed here. */
91	res = gpgme_op_decrypt_result (c->gpg);
92	if (res && res->recipients)
93	recip = res->recipients;
94	}
95	if (recip != NULL && c->gpg_cmd == GPG_CMD_DECRYPT) {
96	for (r = res->recipients; r; r = r->next) {
97	get_pubkey (r->keyid, &key);
98	if (key) {
99	char *uid;
100	id = key->uids->name;
101	if (!id)
102	id = _("Invalid User ID");
103	uid = utf8_to_wincp (id, strlen (id));
104	info = new char [32+strlen (uid)+1 + 4 + strlen (r->keyid)+1
105	+ strlen (key->uids->email)+1];
106	if (!info)
107	BUG (NULL);
108	sprintf (info, "%s <%s> (%s, 0x%s)", uid, key->uids->email,
109	get_key_pubalgo (r->pubkey_algo), r->keyid+8);
110	free (uid);
111
112	}
113	else {
114	info = new char [32 + strlen (r->keyid)+1 + 4];
115	if (!info)
116	BUG (NULL);
117	sprintf (info, _("Unknown key ID (%s, 0x%s)"),
118	get_key_pubalgo (r->pubkey_algo), r->keyid+8);
119	}
120	listbox_add_string (GetDlgItem (dlg, IDC_DECRYPT_LIST), info);
121	free_if_alloc (info);
122	}
123	}
124	else if (c->gpg_cmd == GPG_CMD_DECRYPT)
125	EnableWindow (GetDlgItem (dlg, IDC_DECRYPT_LIST), FALSE);
126	SetDlgItemText (dlg, c->gpg_cmd == GPG_CMD_DECRYPT?
127	IDC_DECRYPT_PWDINFO : IDC_DECRYPT_SIGN_PWDINFO,
128	c->bad_pwd? _("Bad passphrase; Enter passphrase again") :
129	_("Please enter your passphrase"));
130	if (c->gpg_cmd == GPG_CMD_DECRYPT) {
131	SetFocus (GetDlgItem (dlg, IDC_DECRYPT_PWD));
132	if (res && !res->recipients) {
133	const char *s = _("Symmetric encryption.\n"
134	"%s encrypted data.");
135	const char *alg = get_symkey_algo (c->sym.sym_algo);
136	info = new char[strlen (s) + strlen (alg) + 2];
137	if (!info)
138	BUG (NULL);
139	sprintf (info, s, alg);
140	SetDlgItemText (dlg, IDC_DECRYPT_MSG, info);
141	free_if_alloc (info);
142	}
143	else
144	SetDlgItemText (dlg, IDC_DECRYPT_MSG, c->info);
145	}
146	else {
147	SetFocus( GetDlgItem (dlg, IDC_DECRYPT_SIGN_PWD));
148	SetDlgItemText (dlg, IDC_DECRYPT_SIGN_MSG, c->info);
149	}
150	center_window (dlg, NULL);
151	SetForegroundWindow (dlg);
152	set_active_window (dlg);
153	return FALSE;
154
155	case WM_SYSCOMMAND:
156	if (LOWORD (wparam) == SC_CLOSE) {
157	SetDlgItemText (dlg, item_ctrl_id (c->gpg_cmd), "");
158	c->cancel = 1;
159	EndDialog (dlg, TRUE);
160	}
161	break;
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	c->pwd = new char[n+2];
192	if (!c->pwd)
193	BUG (NULL);
194	GetDlgItemText (dlg, item_ctrl_id (c->gpg_cmd), c->pwd, n+1);
195	}
196	res = gpgme_op_decrypt_result (c->gpg);
197	if (!res)
198	res_sig = gpgme_op_sign_result (c->gpg);
199	if (reg_prefs.cache_time > 0 && !c->is_card &&
200	((res && res->recipients) \|\| (res_sig && res_sig->signatures))) {
201	if (agent_get_cache (c->keyid, &item))
202	agent_unlock_cache_entry (&item);
203	else
204	agent_put_cache (c->keyid, c->pwd, reg_prefs.cache_time);
205	}
206	c->cancel = 0;
207	EndDialog (dlg, TRUE);
208	return TRUE;
209
210	case IDCANCEL:
211	SetDlgItemText (dlg, item_ctrl_id (c->gpg_cmd), "");
212	c->cancel = 1;
213	EndDialog (dlg, FALSE);
214	return FALSE;
215	}
216	break;
217	}
218
219	return FALSE;
220	}
221
222
223	/* Extract the main keyid from @pass_info.
224	Return value: long main keyid or NULL for an error. */
225	static const char*
226	parse_gpg_keyid (const char *pass_info)
227	{
228	static char keyid[16+1];
229
230	/* XXX: check for leading alpha-chars? */
231	if (strlen (pass_info) < 16)
232	return NULL;
233	/* the format of the desc buffer looks like this:
234	request_keyid[16] main_keyid[16] keytype[1] keylength[4]
235	we use the main keyid to use only one cache entry. */
236	strncpy (keyid, pass_info+17, 16);
237	keyid[16] = 0;
238	return keyid;
239	}
240
241
242	/* Parse the information in @uid_hint and @pass_info to generate
243	a input message for the user in @desc. */
244	static int
245	parse_gpg_description (const char uid_hint, const char pass_info,
246	char *desc, int size)
247	{
248	gpgme_pubkey_algo_t algo;
249	char usedkey[16+1];
250	char mainkey[16+1];
251	char uid, p;
252	int n=0;
253
254	/* Each uid_hint contains a long key-ID so it is at least 16 bytes. */
255	if (strlen (uid_hint) < 17) {
256	*desc = 0;
257	return -1;
258	}
259
260	while (p = strsep ((char**)&pass_info, " ")) {
261	switch (n++) {
262	case 0: strncpy (mainkey, p, 16); mainkey[16] = 0; break;
263	case 1: strncpy (usedkey, p, 16); usedkey[16] = 0; break;
264	case 2: algo = (gpgme_pubkey_algo_t)atol (p); break;
265	}
266	}
267	uid_hint += 16; /* skip keyid */
268	uid_hint += 1; /* space */
269
270	uid = utf8_to_wincp (uid_hint, strlen (uid_hint));
271
272	if (strcmp (usedkey, mainkey))
273	_snprintf (desc, size-1,
274	_("You need a passphrase to unlock the secret key for\n"
275	"user: \"%s\"\n"
276	"%s key, ID %s (main key ID %s)\n"),
277	uid, get_key_pubalgo (algo), usedkey+8, mainkey+8);
278	else if (!strcmp (usedkey, mainkey))
279	_snprintf (desc, size-1,
280	_("You need a passphrase to unlock the secret key for\n"
281	"user: \"%s\"\n"
282	"%s key, ID %s\n"),
283	uid, get_key_pubalgo (algo), usedkey+8);
284	free (uid);
285	return 0;
286	}
287
288
289	/* Extract the serial number from the card ID @id and return it. */
290	const char*
291	extract_serial_no (const char *id)
292	{
293	static char buf[8];
294	char *p;
295
296	p = strchr (id, '/');
297	if (!p)
298	return NULL;
299	strncpy (buf, id+(p-id)-6, 6);
300	return buf;
301	}
302
303
304	/* Passphrase callback with the ability to support caching. */
305	gpgme_error_t
306	passphrase_cb (void hook, const char uid_hint,
307	const char *passphrase_info,
308	int prev_was_bad, int fd)
309	{
310	passphrase_cb_s c = (passphrase_cb_s)hook;
311	HANDLE hd = (HANDLE)fd;
312	void *item;
313	const char keyid, pass;
314	DWORD n;
315	int rc;
316
317	if (!c)
318	return gpg_error (GPG_ERR_INV_ARG);
319	c->bad_pwd = prev_was_bad? 1 : 0;
320	if (prev_was_bad && !c->cancel) {
321	if (c->pwd)
322	burn_passphrase (&c->pwd);
323	agent_del_cache (c->keyid);
324	c->pwd_init = 1;
325	}
326
327	if (passphrase_info) {
328	if (strlen (passphrase_info) < 16 &&
329	!strstr (passphrase_info, "OPENPGP")) {
330	/* assume symetric encryption. */
331	int n=2;
332	c->sym.sym_algo = atoi (passphrase_info);
333	if (c->sym.sym_algo > 9)
334	n++;
335	/* XXX: be more strict. */
336	c->sym.s2k_mode = atoi (passphrase_info+n);
337	c->sym.s2k_hash = atoi (passphrase_info+n+2);
338	}
339
340	keyid = parse_gpg_keyid (passphrase_info);
341	pass = agent_get_cache (keyid+8, &item);
342	if (pass) {
343	agent_unlock_cache_entry (&item);
344	c->pwd_init = 0;
345	if (!WriteFile (hd, pass, strlen (pass), &n, NULL))
346	log_debug ("passphrase_cb: WriteFile() failed ec=%d\n", w32_errno);
347	if (!WriteFile (hd, "\n", 1, &n, NULL))
348	log_debug ("passphrase_cb: WriteFile() failed ec=%d\n", w32_errno);
349	return 0;
350	}
351	}
352
353	if (c->pwd_init) {
354	if (keyid && strlen (keyid) == 16)
355	strcpy (c->keyid, keyid+8);
356
357	/* if @passphrase_info contains 'OPENPGP' we assume a smart card
358	has been used. */
359	if (strstr (passphrase_info, "OPENPGP")) {
360	const char *s=passphrase_info;
361	while (s && s && s != 'D')
362	s++;
363	_snprintf (c->info, sizeof c->info-1,
364	_("Please enter the PIN to unlock your secret card key\n"
365	"Card: %s"), extract_serial_no (s));
366	c->is_card = 1;
367	}
368	else if (uid_hint)
369	parse_gpg_description (uid_hint, passphrase_info,
370	c->info, sizeof c->info - 1);
371	if (c->gpg_cmd == GPG_CMD_DECRYPT) {
372	rc = DialogBoxParam (glob_hinst, (LPCSTR)IDD_WINPT_DECRYPT,
373	(HWND)c->hwnd, passphrase_callback_proc,
374	(LPARAM)c);
375	}
376	else if (c->gpg_cmd == GPG_CMD_SIGN) {
377	rc = DialogBoxParam (glob_hinst, (LPCSTR)IDD_WINPT_DECRYPT_SIGN,
378	(HWND)c->hwnd, passphrase_callback_proc,
379	(LPARAM)c);
380	}
381	if (rc == -1) {
382	if (!WriteFile (hd, "\n", 1, &n, NULL))
383	log_debug ("passphrase_cb: WriteFile() failed ec=%d\n", w32_errno);
384	return 0;
385	}
386	c->pwd_init = 0;
387	}
388	if (c->cancel) {
389	if (!WriteFile (hd, "\n", 1, &n, NULL))
390	log_debug ("passphrase_cb: WriteFile() failed ec=%d\n", w32_errno);
391	return 0;
392	}
393
394	WriteFile (hd, c->pwd, strlen (c->pwd), &n, NULL);
395	WriteFile (hd, "\n", 1, &n, NULL);
396	return 0;
397	}
398
399
400	/* Initialize the given passphrase callback @cb with the
401	used gpgme context @ctx, the command @cmd and a title
402	@title for the dialog. */
403	void
404	set_gpg_passphrase_cb (passphrase_cb_s *cb, gpgme_ctx_t ctx,
405	int cmd, HWND hwnd, const char *title)
406	{
407	memset (cb, 0, sizeof *cb);
408	cb->gpg_cmd = cmd;
409	cb->bad_pwd = 0;
410	cb->is_card = 0;
411	cb->cancel = 0;
412	cb->hwnd = hwnd;
413	cb->pwd_init = 1;
414	free_if_alloc (cb->title);
415	cb->title = m_strdup (title);
416	if (!cb->title)
417	BUG (NULL);
418	gpgme_set_passphrase_cb (ctx, passphrase_cb, cb);
419	cb->gpg = ctx;
420	}
421
422
423	/* Release a passphrase callback @ctx. */
424	void
425	release_gpg_passphrase_cb (passphrase_cb_s *ctx)
426	{
427	gpgme_recipient_t r, n;
428
429	if (!ctx)
430	return;
431	sfree_if_alloc (ctx->pwd);
432	free_if_alloc (ctx->title);
433	r = ctx->recipients;
434	while (r) {
435	n = r->next;
436	safe_free (r->keyid);
437	safe_free (r);
438	r = n;
439	}
440	}
441
442
443	/* Simple check to measure passphrase (@pass) quality.
444	Return value: 0 on success. */
445	int
446	check_passwd_quality (const char *pass, int strict)
447	{
448	int i, nd=0, nc=0, n;
449
450	n = strlen (pass);
451	if (n < 8)
452	return -1;
453
454	for (i=0; i < n; i++) {
455	if (isdigit (pass[i]))
456	nd++;
457	if (isalpha (pass[i]))
458	nc++;
459	}
460
461	/* check that the passphrase contains letters and numbers. */
462	if (nd == n \|\| nc == n)
463	return -1;
464
465	return 0;
466	}