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 
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#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=NULL;
    gpgme_sign_result_t res_sig=NULL;
    gpgme_key_t key;
    gpgme_recipient_t recip=NULL, r;
    void *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_sig)) {
                    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) {
        log_debug ("parse_gpg_keyid: error '%s'\r\n", pass_info);
        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;

    algo = (gpgme_pubkey_algo_t)0;
    /* Each uid_hint contains a long key-ID so it is at least 16 bytes. */
    if (strlen (uid_hint) < 17) {
        *desc = 0;
        log_debug ("parse_gpg_description: error '%s'\r\n", uid_hint);
        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) {
        log_debug ("extract_serial_no: error '%s'\r\n", id);
        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=NULL, *pass;
    DWORD n;
    int rc = 0;

    if (!c) {
        log_debug ("passphrase_cb: error '!c'\r\n");
        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 pos=2;
            c->sym.sym_algo = atoi (passphrase_info);
            if (c->sym.sym_algo > 9)
                pos++;
            /* XXX: be more strict. */
            c->sym.s2k_mode = atoi (passphrase_info+pos);
            c->sym.s2k_hash = atoi (passphrase_info+pos+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;
    }

    if (!WriteFile (hd, c->pwd, strlen (c->pwd), &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;
}


/* 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	#ifdef HAVE_CONFIG_H
23	#include <config.h>
24	#endif
25
26	#include <windows.h>
27	#include <ctype.h>
28
29	#include "resource.h"
30	#include "wptNLS.h"
31	#include "wptW32API.h"
32	#include "wptVersion.h"
33	#include "wptGPG.h"
34	#include "wptCommonCtl.h"
35	#include "wptContext.h"
36	#include "wptDlgs.h"
37	#include "wptUTF8.h"
38	#include "wptErrors.h"
39	#include "wptTypes.h"
40	#include "wptKeylist.h"
41	#include "wptAgent.h"
42	#include "wptRegistry.h"
43
44	const char* get_symkey_algo (int algo);
45
46	#define item_ctrl_id( cmd ) \
47	((cmd) == GPG_CMD_DECRYPT? IDC_DECRYPT_PWD : IDC_DECRYPT_SIGN_PWD)
48
49	#define item_ctrl_id2(cmd) \
50	((cmd) == GPG_CMD_DECRYPT? IDC_DECRYPT_HIDE : IDC_DECRYPT_SIGN_HIDE)
51
52
53	/* Overwrite passphrase and free memory. */
54	static void
55	burn_passphrase (char **pwd)
56	{
57	char pass = pwd;
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_key_t key;
72	gpgme_recipient_t recip=NULL, r;
73	void *item;
74	const char *id;
75	char *info;
76	int n;
77
78	switch (msg) {
79	case WM_INITDIALOG:
80	c = (passphrase_cb_s *)lparam;
81	if (!c)
82	BUG (0);
83	SetWindowText (dlg, c->title);
84	if (c->gpg_cmd == GPG_CMD_DECRYPT) {
85	SetDlgItemText (dlg, IDC_DECRYPT_LISTINF,
86	_("Encrypted with the following public key(s)"));
87	CheckDlgButton (dlg, IDC_DECRYPT_HIDE, BST_CHECKED);
88	}
89	else if (c->gpg_cmd == GPG_CMD_SIGN)
90	CheckDlgButton (dlg, IDC_DECRYPT_SIGN_HIDE, BST_CHECKED);
91	if (c->recipients)
92	recip = c->recipients; /* recipients were already extracted. */
93	else {
94	/* XXX: not all ENCRYPT_TO entries are listed here. */
95	res = gpgme_op_decrypt_result (c->gpg);
96	if (res && res->recipients)
97	recip = res->recipients;
98	}
99	if (recip != NULL && c->gpg_cmd == GPG_CMD_DECRYPT) {
100	for (r = res->recipients; r; r = r->next) {
101	get_pubkey (r->keyid, &key);
102	if (key) {
103	char *uid;
104	id = key->uids->name;
105	if (!id)
106	id = _("Invalid User ID");
107	uid = utf8_to_wincp (id, strlen (id));
108	info = new char [32+strlen (uid)+1 + 4 + strlen (r->keyid)+1
109	+ strlen (key->uids->email)+1];
110	if (!info)
111	BUG (NULL);
112	sprintf (info, "%s <%s> (%s, 0x%s)", uid, key->uids->email,
113	get_key_pubalgo (r->pubkey_algo), r->keyid+8);
114	free (uid);
115
116	}
117	else {
118	info = new char [32 + strlen (r->keyid)+1 + 4];
119	if (!info)
120	BUG (NULL);
121	sprintf (info, _("Unknown key ID (%s, 0x%s)"),
122	get_key_pubalgo (r->pubkey_algo), r->keyid+8);
123	}
124	listbox_add_string (GetDlgItem (dlg, IDC_DECRYPT_LIST), info);
125	free_if_alloc (info);
126	}
127	}
128	else if (c->gpg_cmd == GPG_CMD_DECRYPT)
129	EnableWindow (GetDlgItem (dlg, IDC_DECRYPT_LIST), FALSE);
130	SetDlgItemText (dlg, c->gpg_cmd == GPG_CMD_DECRYPT?
131	IDC_DECRYPT_PWDINFO : IDC_DECRYPT_SIGN_PWDINFO,
132	c->bad_pwd? _("Bad passphrase; Enter passphrase again") :
133	_("Please enter your passphrase"));
134	if (c->gpg_cmd == GPG_CMD_DECRYPT) {
135	SetFocus (GetDlgItem (dlg, IDC_DECRYPT_PWD));
136	if (res && !res->recipients) {
137	const char *s = _("Symmetric encryption.\n"
138	"%s encrypted data.");
139	const char *alg = get_symkey_algo (c->sym.sym_algo);
140	info = new char[strlen (s) + strlen (alg) + 2];
141	if (!info)
142	BUG (NULL);
143	sprintf (info, s, alg);
144	SetDlgItemText (dlg, IDC_DECRYPT_MSG, info);
145	free_if_alloc (info);
146	}
147	else
148	SetDlgItemText (dlg, IDC_DECRYPT_MSG, c->info);
149	}
150	else {
151	SetFocus( GetDlgItem (dlg, IDC_DECRYPT_SIGN_PWD));
152	SetDlgItemText (dlg, IDC_DECRYPT_SIGN_MSG, c->info);
153	}
154	center_window (dlg, NULL);
155	SetForegroundWindow (dlg);
156	set_active_window (dlg);
157	return FALSE;
158
159	case WM_SYSCOMMAND:
160	if (LOWORD (wparam) == SC_CLOSE) {
161	SetDlgItemText (dlg, item_ctrl_id (c->gpg_cmd), "");
162	c->cancel = 1;
163	EndDialog (dlg, TRUE);
164	}
165	break;
166
167	case WM_COMMAND:
168	switch (HIWORD (wparam)) {
169	case BN_CLICKED:
170	if (LOWORD (wparam) == IDC_DECRYPT_HIDE
171	\|\| LOWORD (wparam) == IDC_DECRYPT_SIGN_HIDE) {
172	HWND hwnd;
173	int hide = IsDlgButtonChecked (dlg, item_ctrl_id2 (c->gpg_cmd));
174	hwnd = GetDlgItem (dlg, item_ctrl_id (c->gpg_cmd));
175	SendMessage (hwnd, EM_SETPASSWORDCHAR, hide? '*' : 0, 0);
176	SetFocus (hwnd);
177	}
178	}
179
180	switch (LOWORD (wparam)) {
181	case IDOK:
182	/* XXX: the item is even cached when the passphrase is not
183	correct, which means that the user needs to delete all
184	cached entries to continue. */
185	if (c->pwd)
186	burn_passphrase (&c->pwd);
187	n = item_get_text_length (dlg, item_ctrl_id (c->gpg_cmd));
188	if (!n) {
189	c->pwd = new char[2];
190	if (!c->pwd)
191	BUG (NULL);
192	strcpy (c->pwd, "");
193	}
194	else {
195	c->pwd = new char[n+2];
196	if (!c->pwd)
197	BUG (NULL);
198	GetDlgItemText (dlg, item_ctrl_id (c->gpg_cmd), c->pwd, n+1);
199	}
200	res = gpgme_op_decrypt_result (c->gpg);
201	if (!res)
202	res_sig = gpgme_op_sign_result (c->gpg);
203	if (reg_prefs.cache_time > 0 && !c->is_card &&
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 FALSE;
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 uid, p;
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_wincp (uid_hint, strlen (uid_hint));
279
280	if (strcmp (usedkey, mainkey))
281	_snprintf (desc, size-1,
282	_("You need a passphrase to unlock the secret key for\n"
283	"user: \"%s\"\n"
284	"%s key, ID %s (main key ID %s)\n"),
285	uid, get_key_pubalgo (algo), usedkey+8, mainkey+8);
286	else if (!strcmp (usedkey, mainkey))
287	_snprintf (desc, size-1,
288	_("You need a passphrase to unlock the secret key for\n"
289	"user: \"%s\"\n"
290	"%s key, ID %s\n"),
291	uid, get_key_pubalgo (algo), usedkey+8);
292	free (uid);
293	return 0;
294	}
295
296
297	/* Extract the serial number from the card ID @id and return it. */
298	const char*
299	extract_serial_no (const char *id)
300	{
301	static char buf[8];
302	char *p;
303
304	p = strchr (id, '/');
305	if (!p) {
306	log_debug ("extract_serial_no: error '%s'\r\n", id);
307	return NULL;
308	}
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 '!c'\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	return 0;
397	}
398	c->pwd_init = 0;
399	}
400	if (c->cancel) {
401	if (!WriteFile (hd, "\n", 1, &n, NULL))
402	log_debug ("passphrase_cb: WriteFile() failed ec=%d\n", w32_errno);
403	return 0;
404	}
405
406	if (!WriteFile (hd, c->pwd, strlen (c->pwd), &n, NULL))
407	log_debug ("passphrase_cb: WriteFile() failed ec=%d\n", w32_errno);
408	if (!WriteFile (hd, "\n", 1, &n, NULL))
409	log_debug ("passphrase_cb: WriteFile() failed ec=%d\n", w32_errno);
410	return 0;
411	}
412
413
414	/* Initialize the given passphrase callback @cb with the
415	used gpgme context @ctx, the command @cmd and a title
416	@title for the dialog. */
417	void
418	set_gpg_passphrase_cb (passphrase_cb_s *cb, gpgme_ctx_t ctx,
419	int cmd, HWND hwnd, const char *title)
420	{
421	memset (cb, 0, sizeof *cb);
422	cb->gpg_cmd = cmd;
423	cb->bad_pwd = 0;
424	cb->is_card = 0;
425	cb->cancel = 0;
426	cb->hwnd = hwnd;
427	cb->pwd_init = 1;
428	free_if_alloc (cb->title);
429	cb->title = m_strdup (title);
430	if (!cb->title)
431	BUG (NULL);
432	gpgme_set_passphrase_cb (ctx, passphrase_cb, cb);
433	cb->gpg = ctx;
434	}
435
436
437	/* Release a passphrase callback @ctx. */
438	void
439	release_gpg_passphrase_cb (passphrase_cb_s *ctx)
440	{
441	gpgme_recipient_t r, n;
442
443	if (!ctx)
444	return;
445	sfree_if_alloc (ctx->pwd);
446	free_if_alloc (ctx->title);
447	r = ctx->recipients;
448	while (r) {
449	n = r->next;
450	safe_free (r->keyid);
451	safe_free (r);
452	r = n;
453	}
454	}
455
456
457	/* Simple check to measure passphrase (@pass) quality.
458	Return value: 0 on success. */
459	int
460	check_passwd_quality (const char *pass, int strict)
461	{
462	int i, nd=0, nc=0, n;
463
464	n = strlen (pass);
465	if (n < 8)
466	return -1;
467
468	for (i=0; i < n; i++) {
469	if (isdigit (pass[i]))
470	nd++;
471	if (isalpha (pass[i]))
472	nc++;
473	}
474
475	/* check that the passphrase contains letters and numbers. */
476	if (nd == n \|\| nc == n)
477	return -1;
478
479	return 0;
480	}