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->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;

    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;
        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=NULL, *pass;
    DWORD n;
    int rc=0;

    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 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;
    }

    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	werner	36	/* 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	werner	47	#include "resource.h"
30	werner	36	#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	werner	48	#include "wptKeylist.h"
41	werner	36	#include "wptAgent.h"
42			#include "wptRegistry.h"
43
44	werner	48
45
46	werner	36	const char* get_symkey_algo (int algo);
47
48			#define item_ctrl_id( cmd ) \
49			((cmd) == GPG_CMD_DECRYPT? IDC_DECRYPT_PWD : IDC_DECRYPT_SIGN_PWD)
50
51			#define item_ctrl_id2(cmd) \
52			((cmd) == GPG_CMD_DECRYPT? IDC_DECRYPT_HIDE : IDC_DECRYPT_SIGN_HIDE)
53
54
55			/* Overwrite passphrase and free memory. */
56			static void
57			burn_passphrase (char **pwd)
58			{
59			char pass = pwd;
60			wipememory (pass, strlen (pass));
61			delete []pass;
62			*pwd = NULL;
63			}
64
65
66			/* Dialog procedure for the passphrase callback. */
67			static BOOL CALLBACK
68			passphrase_callback_proc (HWND dlg, UINT msg, WPARAM wparam, LPARAM lparam)
69			{
70			static passphrase_cb_s * c;
71	twoaday	69	gpgme_decrypt_result_t res = NULL;
72			gpgme_sign_result_t res_sig = NULL;
73	werner	36	gpgme_key_t key;
74	twoaday	69	gpgme_recipient_t recip=NULL, r;
75			void *item;
76	werner	36	const char *id;
77			char *info;
78			int n;
79
80			switch (msg) {
81			case WM_INITDIALOG:
82			c = (passphrase_cb_s *)lparam;
83			if (!c)
84			BUG (0);
85			SetWindowText (dlg, c->title);
86			if (c->gpg_cmd == GPG_CMD_DECRYPT) {
87			SetDlgItemText (dlg, IDC_DECRYPT_LISTINF,
88			_("Encrypted with the following public key(s)"));
89			CheckDlgButton (dlg, IDC_DECRYPT_HIDE, BST_CHECKED);
90			}
91			else if (c->gpg_cmd == GPG_CMD_SIGN)
92			CheckDlgButton (dlg, IDC_DECRYPT_SIGN_HIDE, BST_CHECKED);
93			if (c->recipients)
94			recip = c->recipients; /* recipients were already extracted. */
95			else {
96			/* XXX: not all ENCRYPT_TO entries are listed here. */
97			res = gpgme_op_decrypt_result (c->gpg);
98			if (res && res->recipients)
99			recip = res->recipients;
100			}
101			if (recip != NULL && c->gpg_cmd == GPG_CMD_DECRYPT) {
102			for (r = res->recipients; r; r = r->next) {
103			get_pubkey (r->keyid, &key);
104			if (key) {
105			char *uid;
106			id = key->uids->name;
107			if (!id)
108			id = _("Invalid User ID");
109			uid = utf8_to_wincp (id, strlen (id));
110			info = new char [32+strlen (uid)+1 + 4 + strlen (r->keyid)+1
111			+ strlen (key->uids->email)+1];
112			if (!info)
113			BUG (NULL);
114			sprintf (info, "%s <%s> (%s, 0x%s)", uid, key->uids->email,
115			get_key_pubalgo (r->pubkey_algo), r->keyid+8);
116			free (uid);
117
118			}
119			else {
120			info = new char [32 + strlen (r->keyid)+1 + 4];
121			if (!info)
122			BUG (NULL);
123			sprintf (info, _("Unknown key ID (%s, 0x%s)"),
124			get_key_pubalgo (r->pubkey_algo), r->keyid+8);
125			}
126			listbox_add_string (GetDlgItem (dlg, IDC_DECRYPT_LIST), info);
127			free_if_alloc (info);
128			}
129			}
130			else if (c->gpg_cmd == GPG_CMD_DECRYPT)
131			EnableWindow (GetDlgItem (dlg, IDC_DECRYPT_LIST), FALSE);
132			SetDlgItemText (dlg, c->gpg_cmd == GPG_CMD_DECRYPT?
133			IDC_DECRYPT_PWDINFO : IDC_DECRYPT_SIGN_PWDINFO,
134			c->bad_pwd? _("Bad passphrase; Enter passphrase again") :
135			_("Please enter your passphrase"));
136			if (c->gpg_cmd == GPG_CMD_DECRYPT) {
137			SetFocus (GetDlgItem (dlg, IDC_DECRYPT_PWD));
138			if (res && !res->recipients) {
139			const char *s = _("Symmetric encryption.\n"
140			"%s encrypted data.");
141			const char *alg = get_symkey_algo (c->sym.sym_algo);
142			info = new char[strlen (s) + strlen (alg) + 2];
143			if (!info)
144			BUG (NULL);
145			sprintf (info, s, alg);
146			SetDlgItemText (dlg, IDC_DECRYPT_MSG, info);
147			free_if_alloc (info);
148			}
149			else
150			SetDlgItemText (dlg, IDC_DECRYPT_MSG, c->info);
151			}
152			else {
153			SetFocus( GetDlgItem (dlg, IDC_DECRYPT_SIGN_PWD));
154			SetDlgItemText (dlg, IDC_DECRYPT_SIGN_MSG, c->info);
155			}
156			center_window (dlg, NULL);
157			SetForegroundWindow (dlg);
158			set_active_window (dlg);
159			return FALSE;
160
161			case WM_SYSCOMMAND:
162			if (LOWORD (wparam) == SC_CLOSE) {
163			SetDlgItemText (dlg, item_ctrl_id (c->gpg_cmd), "");
164			c->cancel = 1;
165			EndDialog (dlg, TRUE);
166			}
167			break;
168
169			case WM_COMMAND:
170			switch (HIWORD (wparam)) {
171			case BN_CLICKED:
172			if (LOWORD (wparam) == IDC_DECRYPT_HIDE
173			\|\| LOWORD (wparam) == IDC_DECRYPT_SIGN_HIDE) {
174			HWND hwnd;
175			int hide = IsDlgButtonChecked (dlg, item_ctrl_id2 (c->gpg_cmd));
176			hwnd = GetDlgItem (dlg, item_ctrl_id (c->gpg_cmd));
177			SendMessage (hwnd, EM_SETPASSWORDCHAR, hide? '*' : 0, 0);
178			SetFocus (hwnd);
179			}
180			}
181
182			switch (LOWORD (wparam)) {
183			case IDOK:
184			/* XXX: the item is even cached when the passphrase is not
185			correct, which means that the user needs to delete all
186			cached entries to continue. */
187			if (c->pwd)
188			burn_passphrase (&c->pwd);
189			n = item_get_text_length (dlg, item_ctrl_id (c->gpg_cmd));
190			if (!n) {
191			c->pwd = new char[2];
192			if (!c->pwd)
193			BUG (NULL);
194			strcpy (c->pwd, "");
195			}
196			else {
197			c->pwd = new char[n+2];
198			if (!c->pwd)
199			BUG (NULL);
200			GetDlgItemText (dlg, item_ctrl_id (c->gpg_cmd), c->pwd, n+1);
201			}
202			res = gpgme_op_decrypt_result (c->gpg);
203			if (!res)
204			res_sig = gpgme_op_sign_result (c->gpg);
205			if (reg_prefs.cache_time > 0 && !c->is_card &&
206			((res && res->recipients) \|\| (res_sig && res_sig->signatures))) {
207			if (agent_get_cache (c->keyid, &item))
208			agent_unlock_cache_entry (&item);
209			else
210			agent_put_cache (c->keyid, c->pwd, reg_prefs.cache_time);
211			}
212			c->cancel = 0;
213			EndDialog (dlg, TRUE);
214			return TRUE;
215
216			case IDCANCEL:
217			SetDlgItemText (dlg, item_ctrl_id (c->gpg_cmd), "");
218			c->cancel = 1;
219			EndDialog (dlg, FALSE);
220			return FALSE;
221			}
222			break;
223			}
224
225			return FALSE;
226			}
227
228
229			/* Extract the main keyid from @pass_info.
230			Return value: long main keyid or NULL for an error. */
231			static const char*
232			parse_gpg_keyid (const char *pass_info)
233			{
234			static char keyid[16+1];
235
236			/* XXX: check for leading alpha-chars? */
237			if (strlen (pass_info) < 16)
238			return NULL;
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	twoaday	69	algo = (gpgme_pubkey_algo_t)0;
261	werner	36	/* 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			return -1;
265			}
266
267			while (p = strsep ((char**)&pass_info, " ")) {
268			switch (n++) {
269			case 0: strncpy (mainkey, p, 16); mainkey[16] = 0; break;
270			case 1: strncpy (usedkey, p, 16); usedkey[16] = 0; break;
271			case 2: algo = (gpgme_pubkey_algo_t)atol (p); break;
272			}
273			}
274			uid_hint += 16; /* skip keyid */
275			uid_hint += 1; /* space */
276
277			uid = utf8_to_wincp (uid_hint, strlen (uid_hint));
278
279			if (strcmp (usedkey, mainkey))
280			_snprintf (desc, size-1,
281			_("You need a passphrase to unlock the secret key for\n"
282			"user: \"%s\"\n"
283			"%s key, ID %s (main key ID %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\n"
288			"user: \"%s\"\n"
289			"%s key, ID %s\n"),
290			uid, get_key_pubalgo (algo), usedkey+8);
291			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			return NULL;
306			strncpy (buf, id+(p-id)-6, 6);
307			return buf;
308			}
309
310
311			/* Passphrase callback with the ability to support caching. */
312			gpgme_error_t
313			passphrase_cb (void hook, const char uid_hint,
314			const char *passphrase_info,
315			int prev_was_bad, int fd)
316			{
317			passphrase_cb_s c = (passphrase_cb_s)hook;
318			HANDLE hd = (HANDLE)fd;
319			void *item;
320	twoaday	69	const char keyid=NULL, pass;
321	werner	36	DWORD n;
322	twoaday	69	int rc=0;
323	werner	36
324			if (!c)
325			return gpg_error (GPG_ERR_INV_ARG);
326			c->bad_pwd = prev_was_bad? 1 : 0;
327			if (prev_was_bad && !c->cancel) {
328			if (c->pwd)
329			burn_passphrase (&c->pwd);
330			agent_del_cache (c->keyid);
331			c->pwd_init = 1;
332			}
333
334			if (passphrase_info) {
335			if (strlen (passphrase_info) < 16 &&
336			!strstr (passphrase_info, "OPENPGP")) {
337			/* assume symetric encryption. */
338	twoaday	69	int pos=2;
339	werner	36	c->sym.sym_algo = atoi (passphrase_info);
340			if (c->sym.sym_algo > 9)
341	twoaday	69	pos++;
342	werner	36	/* XXX: be more strict. */
343	twoaday	69	c->sym.s2k_mode = atoi (passphrase_info+pos);
344			c->sym.s2k_hash = atoi (passphrase_info+pos+2);
345	werner	36	}
346
347			keyid = parse_gpg_keyid (passphrase_info);
348			pass = agent_get_cache (keyid+8, &item);
349			if (pass) {
350			agent_unlock_cache_entry (&item);
351			c->pwd_init = 0;
352			if (!WriteFile (hd, pass, strlen (pass), &n, NULL))
353			log_debug ("passphrase_cb: WriteFile() failed ec=%d\n", w32_errno);
354			if (!WriteFile (hd, "\n", 1, &n, NULL))
355			log_debug ("passphrase_cb: WriteFile() failed ec=%d\n", w32_errno);
356			return 0;
357			}
358			}
359
360			if (c->pwd_init) {
361			if (keyid && strlen (keyid) == 16)
362			strcpy (c->keyid, keyid+8);
363
364			/* if @passphrase_info contains 'OPENPGP' we assume a smart card
365			has been used. */
366			if (strstr (passphrase_info, "OPENPGP")) {
367			const char *s=passphrase_info;
368			while (s && s && s != 'D')
369			s++;
370			_snprintf (c->info, sizeof c->info-1,
371			_("Please enter the PIN to unlock your secret card key\n"
372			"Card: %s"), extract_serial_no (s));
373			c->is_card = 1;
374			}
375			else if (uid_hint)
376			parse_gpg_description (uid_hint, passphrase_info,
377			c->info, sizeof c->info - 1);
378			if (c->gpg_cmd == GPG_CMD_DECRYPT) {
379			rc = DialogBoxParam (glob_hinst, (LPCSTR)IDD_WINPT_DECRYPT,
380			(HWND)c->hwnd, passphrase_callback_proc,
381			(LPARAM)c);
382			}
383			else if (c->gpg_cmd == GPG_CMD_SIGN) {
384			rc = DialogBoxParam (glob_hinst, (LPCSTR)IDD_WINPT_DECRYPT_SIGN,
385			(HWND)c->hwnd, passphrase_callback_proc,
386			(LPARAM)c);
387			}
388			if (rc == -1) {
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			c->pwd_init = 0;
394			}
395			if (c->cancel) {
396			if (!WriteFile (hd, "\n", 1, &n, NULL))
397			log_debug ("passphrase_cb: WriteFile() failed ec=%d\n", w32_errno);
398			return 0;
399			}
400
401			WriteFile (hd, c->pwd, strlen (c->pwd), &n, NULL);
402			WriteFile (hd, "\n", 1, &n, NULL);
403			return 0;
404			}
405
406
407			/* Initialize the given passphrase callback @cb with the
408			used gpgme context @ctx, the command @cmd and a title
409			@title for the dialog. */
410			void
411			set_gpg_passphrase_cb (passphrase_cb_s *cb, gpgme_ctx_t ctx,
412			int cmd, HWND hwnd, const char *title)
413			{
414			memset (cb, 0, sizeof *cb);
415			cb->gpg_cmd = cmd;
416			cb->bad_pwd = 0;
417			cb->is_card = 0;
418			cb->cancel = 0;
419			cb->hwnd = hwnd;
420			cb->pwd_init = 1;
421			free_if_alloc (cb->title);
422			cb->title = m_strdup (title);
423			if (!cb->title)
424			BUG (NULL);
425			gpgme_set_passphrase_cb (ctx, passphrase_cb, cb);
426			cb->gpg = ctx;
427			}
428
429
430			/* Release a passphrase callback @ctx. */
431			void
432			release_gpg_passphrase_cb (passphrase_cb_s *ctx)
433			{
434			gpgme_recipient_t r, n;
435
436			if (!ctx)
437			return;
438			sfree_if_alloc (ctx->pwd);
439			free_if_alloc (ctx->title);
440			r = ctx->recipients;
441			while (r) {
442			n = r->next;
443			safe_free (r->keyid);
444			safe_free (r);
445			r = n;
446			}
447			}
448
449
450			/* Simple check to measure passphrase (@pass) quality.
451			Return value: 0 on success. */
452			int
453			check_passwd_quality (const char *pass, int strict)
454			{
455			int i, nd=0, nc=0, n;
456
457			n = strlen (pass);
458			if (n < 8)
459			return -1;
460
461			for (i=0; i < n; i++) {
462			if (isdigit (pass[i]))
463			nd++;
464			if (isalpha (pass[i]))
465			nc++;
466			}
467
468			/* check that the passphrase contains letters and numbers. */
469			if (nd == n \|\| nc == n)
470			return -1;
471
472			return 0;
473			}