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 <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	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 <windows.h>
28			#include <ctype.h>
29
30			#include "../resource.h"
31			#include "wptNLS.h"
32			#include "wptW32API.h"
33			#include "wptVersion.h"
34			#include "wptGPG.h"
35			#include "wptCommonCtl.h"
36			#include "wptContext.h"
37			#include "wptDlgs.h"
38			#include "wptUTF8.h"
39			#include "wptErrors.h"
40			#include "wptTypes.h"
41			#include "wptKeyList.h"
42			#include "wptAgent.h"
43			#include "wptRegistry.h"
44
45			const char* get_symkey_algo (int algo);
46
47			#define item_ctrl_id( cmd ) \
48			((cmd) == GPG_CMD_DECRYPT? IDC_DECRYPT_PWD : IDC_DECRYPT_SIGN_PWD)
49
50			#define item_ctrl_id2(cmd) \
51			((cmd) == GPG_CMD_DECRYPT? IDC_DECRYPT_HIDE : IDC_DECRYPT_SIGN_HIDE)
52
53
54			/* Overwrite passphrase and free memory. */
55			static void
56			burn_passphrase (char **pwd)
57			{
58			char pass = pwd;
59			wipememory (pass, strlen (pass));
60			delete []pass;
61			*pwd = NULL;
62			}
63
64
65			/* Dialog procedure for the passphrase callback. */
66			static BOOL CALLBACK
67			passphrase_callback_proc (HWND dlg, UINT msg, WPARAM wparam, LPARAM lparam)
68			{
69			static passphrase_cb_s * c;
70			gpgme_decrypt_result_t res;
71			gpgme_sign_result_t res_sig;
72			gpgme_key_t key;
73			gpgme_recipient_t recip, r;
74			void ctx = NULL, item;
75			const char *id;
76			char *info;
77			int n;
78
79			switch (msg) {
80			case WM_INITDIALOG:
81			c = (passphrase_cb_s *)lparam;
82			if (!c)
83			BUG (0);
84			SetWindowText (dlg, c->title);
85			if (c->gpg_cmd == GPG_CMD_DECRYPT) {
86			SetDlgItemText (dlg, IDC_DECRYPT_LISTINF,
87			_("Encrypted with the following public key(s)"));
88			CheckDlgButton (dlg, IDC_DECRYPT_HIDE, BST_CHECKED);
89			}
90			else if (c->gpg_cmd == GPG_CMD_SIGN)
91			CheckDlgButton (dlg, IDC_DECRYPT_SIGN_HIDE, BST_CHECKED);
92			if (c->recipients)
93			recip = c->recipients; /* recipients were already extracted. */
94			else {
95			/* XXX: not all ENCRYPT_TO entries are listed here. */
96			res = gpgme_op_decrypt_result (c->gpg);
97			if (res && res->recipients)
98			recip = res->recipients;
99			}
100			if (recip != NULL && c->gpg_cmd == GPG_CMD_DECRYPT) {
101			for (r = res->recipients; r; r = r->next) {
102			get_pubkey (r->keyid, &key);
103			if (key) {
104			char *uid;
105			id = key->uids->name;
106			if (!id)
107			id = _("Invalid User ID");
108			uid = utf8_to_wincp (id, strlen (id));
109			info = new char [32+strlen (uid)+1 + 4 + strlen (r->keyid)+1
110			+ strlen (key->uids->email)+1];
111			if (!info)
112			BUG (NULL);
113			sprintf (info, "%s <%s> (%s, 0x%s)", uid, key->uids->email,
114			get_key_pubalgo (r->pubkey_algo), r->keyid+8);
115			free (uid);
116
117			}
118			else {
119			info = new char [32 + strlen (r->keyid)+1 + 4];
120			if (!info)
121			BUG (NULL);
122			sprintf (info, _("Unknown key ID (%s, 0x%s)"),
123			get_key_pubalgo (r->pubkey_algo), r->keyid+8);
124			}
125			listbox_add_string (GetDlgItem (dlg, IDC_DECRYPT_LIST), info);
126			free_if_alloc (info);
127			}
128			}
129			else if (c->gpg_cmd == GPG_CMD_DECRYPT)
130			EnableWindow (GetDlgItem (dlg, IDC_DECRYPT_LIST), FALSE);
131			SetDlgItemText (dlg, c->gpg_cmd == GPG_CMD_DECRYPT?
132			IDC_DECRYPT_PWDINFO : IDC_DECRYPT_SIGN_PWDINFO,
133			c->bad_pwd? _("Bad passphrase; Enter passphrase again") :
134			_("Please enter your passphrase"));
135			if (c->gpg_cmd == GPG_CMD_DECRYPT) {
136			SetFocus (GetDlgItem (dlg, IDC_DECRYPT_PWD));
137			if (res && !res->recipients) {
138			const char *s = _("Symmetric encryption.\n"
139			"%s encrypted data.");
140			const char *alg = get_symkey_algo (c->sym.sym_algo);
141			info = new char[strlen (s) + strlen (alg) + 2];
142			if (!info)
143			BUG (NULL);
144			sprintf (info, s, alg);
145			SetDlgItemText (dlg, IDC_DECRYPT_MSG, info);
146			free_if_alloc (info);
147			}
148			else
149			SetDlgItemText (dlg, IDC_DECRYPT_MSG, c->info);
150			}
151			else {
152			SetFocus( GetDlgItem (dlg, IDC_DECRYPT_SIGN_PWD));
153			SetDlgItemText (dlg, IDC_DECRYPT_SIGN_MSG, c->info);
154			}
155			center_window (dlg, NULL);
156			SetForegroundWindow (dlg);
157			set_active_window (dlg);
158			return FALSE;
159
160			case WM_SYSCOMMAND:
161			if (LOWORD (wparam) == SC_CLOSE) {
162			SetDlgItemText (dlg, item_ctrl_id (c->gpg_cmd), "");
163			c->cancel = 1;
164			EndDialog (dlg, TRUE);
165			}
166			break;
167
168			case WM_COMMAND:
169			switch (HIWORD (wparam)) {
170			case BN_CLICKED:
171			if (LOWORD (wparam) == IDC_DECRYPT_HIDE
172			\|\| LOWORD (wparam) == IDC_DECRYPT_SIGN_HIDE) {
173			HWND hwnd;
174			int hide = IsDlgButtonChecked (dlg, item_ctrl_id2 (c->gpg_cmd));
175			hwnd = GetDlgItem (dlg, item_ctrl_id (c->gpg_cmd));
176			SendMessage (hwnd, EM_SETPASSWORDCHAR, hide? '*' : 0, 0);
177			SetFocus (hwnd);
178			}
179			}
180
181			switch (LOWORD (wparam)) {
182			case IDOK:
183			/* XXX: the item is even cached when the passphrase is not
184			correct, which means that the user needs to delete all
185			cached entries to continue. */
186			if (c->pwd)
187			burn_passphrase (&c->pwd);
188			n = item_get_text_length (dlg, item_ctrl_id (c->gpg_cmd));
189			if (!n) {
190			c->pwd = new char[2];
191			if (!c->pwd)
192			BUG (NULL);
193			strcpy (c->pwd, "");
194			}
195			else {
196			c->pwd = new char[n+2];
197			if (!c->pwd)
198			BUG (NULL);
199			GetDlgItemText (dlg, item_ctrl_id (c->gpg_cmd), c->pwd, n+1);
200			}
201			res = gpgme_op_decrypt_result (c->gpg);
202			if (!res)
203			res_sig = gpgme_op_sign_result (c->gpg);
204			if (reg_prefs.cache_time > 0 && !c->is_card &&
205			((res && res->recipients) \|\| (res_sig && res_sig->signatures))) {
206			if (agent_get_cache (c->keyid, &item))
207			agent_unlock_cache_entry (&item);
208			else
209			agent_put_cache (c->keyid, c->pwd, reg_prefs.cache_time);
210			}
211			c->cancel = 0;
212			EndDialog (dlg, TRUE);
213			return TRUE;
214
215			case IDCANCEL:
216			SetDlgItemText (dlg, item_ctrl_id (c->gpg_cmd), "");
217			c->cancel = 1;
218			EndDialog (dlg, FALSE);
219			return FALSE;
220			}
221			break;
222			}
223
224			return FALSE;
225			}
226
227
228			/* Extract the main keyid from @pass_info.
229			Return value: long main keyid or NULL for an error. */
230			static const char*
231			parse_gpg_keyid (const char *pass_info)
232			{
233			static char keyid[16+1];
234
235			/* XXX: check for leading alpha-chars? */
236			if (strlen (pass_info) < 16)
237			return NULL;
238			/* the format of the desc buffer looks like this:
239			request_keyid[16] main_keyid[16] keytype[1] keylength[4]
240			we use the main keyid to use only one cache entry. */
241			strncpy (keyid, pass_info+17, 16);
242			keyid[16] = 0;
243			return keyid;
244			}
245
246
247			/* Parse the information in @uid_hint and @pass_info to generate
248			a input message for the user in @desc. */
249			static int
250			parse_gpg_description (const char uid_hint, const char pass_info,
251			char *desc, int size)
252			{
253			gpgme_pubkey_algo_t algo;
254			char usedkey[16+1];
255			char mainkey[16+1];
256			char uid, p;
257			int n=0;
258
259			/* Each uid_hint contains a long key-ID so it is at least 16 bytes. */
260			if (strlen (uid_hint) < 17) {
261			*desc = 0;
262			return -1;
263			}
264
265			while (p = strsep ((char**)&pass_info, " ")) {
266			switch (n++) {
267			case 0: strncpy (mainkey, p, 16); mainkey[16] = 0; break;
268			case 1: strncpy (usedkey, p, 16); usedkey[16] = 0; break;
269			case 2: algo = (gpgme_pubkey_algo_t)atol (p); break;
270			}
271			}
272			uid_hint += 16; /* skip keyid */
273			uid_hint += 1; /* space */
274
275			uid = utf8_to_wincp (uid_hint, strlen (uid_hint));
276
277			if (strcmp (usedkey, mainkey))
278			_snprintf (desc, size-1,
279			_("You need a passphrase to unlock the secret key for\n"
280			"user: \"%s\"\n"
281			"%s key, ID %s (main key ID %s)\n"),
282			uid, get_key_pubalgo (algo), usedkey+8, mainkey+8);
283			else if (!strcmp (usedkey, mainkey))
284			_snprintf (desc, size-1,
285			_("You need a passphrase to unlock the secret key for\n"
286			"user: \"%s\"\n"
287			"%s key, ID %s\n"),
288			uid, get_key_pubalgo (algo), usedkey+8);
289			free (uid);
290			return 0;
291			}
292
293
294			/* Extract the serial number from the card ID @id and return it. */
295			const char*
296			extract_serial_no (const char *id)
297			{
298			static char buf[8];
299			char *p;
300
301			p = strchr (id, '/');
302			if (!p)
303			return NULL;
304			strncpy (buf, id+(p-id)-6, 6);
305			return buf;
306			}
307
308
309			/* Passphrase callback with the ability to support caching. */
310			gpgme_error_t
311			passphrase_cb (void hook, const char uid_hint,
312			const char *passphrase_info,
313			int prev_was_bad, int fd)
314			{
315			passphrase_cb_s c = (passphrase_cb_s)hook;
316			HANDLE hd = (HANDLE)fd;
317			void *item;
318			const char keyid, pass;
319			DWORD n;
320			int rc;
321
322			if (!c)
323			return gpg_error (GPG_ERR_INV_ARG);
324			c->bad_pwd = prev_was_bad? 1 : 0;
325			if (prev_was_bad && !c->cancel) {
326			if (c->pwd)
327			burn_passphrase (&c->pwd);
328			agent_del_cache (c->keyid);
329			c->pwd_init = 1;
330			}
331
332			if (passphrase_info) {
333			if (strlen (passphrase_info) < 16 &&
334			!strstr (passphrase_info, "OPENPGP")) {
335			/* assume symetric encryption. */
336			int n=2;
337			c->sym.sym_algo = atoi (passphrase_info);
338			if (c->sym.sym_algo > 9)
339			n++;
340			/* XXX: be more strict. */
341			c->sym.s2k_mode = atoi (passphrase_info+n);
342			c->sym.s2k_hash = atoi (passphrase_info+n+2);
343			}
344
345			keyid = parse_gpg_keyid (passphrase_info);
346			pass = agent_get_cache (keyid+8, &item);
347			if (pass) {
348			agent_unlock_cache_entry (&item);
349			c->pwd_init = 0;
350			if (!WriteFile (hd, pass, strlen (pass), &n, NULL))
351			log_debug ("passphrase_cb: WriteFile() failed ec=%d\n", w32_errno);
352			if (!WriteFile (hd, "\n", 1, &n, NULL))
353			log_debug ("passphrase_cb: WriteFile() failed ec=%d\n", w32_errno);
354			return 0;
355			}
356			}
357
358			if (c->pwd_init) {
359			if (keyid && strlen (keyid) == 16)
360			strcpy (c->keyid, keyid+8);
361
362			/* if @passphrase_info contains 'OPENPGP' we assume a smart card
363			has been used. */
364			if (strstr (passphrase_info, "OPENPGP")) {
365			const char *s=passphrase_info;
366			while (s && s && s != 'D')
367			s++;
368			_snprintf (c->info, sizeof c->info-1,
369			_("Please enter the PIN to unlock your secret card key\n"
370			"Card: %s"), extract_serial_no (s));
371			c->is_card = 1;
372			}
373			else if (uid_hint)
374			parse_gpg_description (uid_hint, passphrase_info,
375			c->info, sizeof c->info - 1);
376			if (c->gpg_cmd == GPG_CMD_DECRYPT) {
377			rc = DialogBoxParam (glob_hinst, (LPCSTR)IDD_WINPT_DECRYPT,
378			(HWND)c->hwnd, passphrase_callback_proc,
379			(LPARAM)c);
380			}
381			else if (c->gpg_cmd == GPG_CMD_SIGN) {
382			rc = DialogBoxParam (glob_hinst, (LPCSTR)IDD_WINPT_DECRYPT_SIGN,
383			(HWND)c->hwnd, passphrase_callback_proc,
384			(LPARAM)c);
385			}
386			if (rc == -1) {
387			if (!WriteFile (hd, "\n", 1, &n, NULL))
388			log_debug ("passphrase_cb: WriteFile() failed ec=%d\n", w32_errno);
389			return 0;
390			}
391			c->pwd_init = 0;
392			}
393			if (c->cancel) {
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
399			WriteFile (hd, c->pwd, strlen (c->pwd), &n, NULL);
400			WriteFile (hd, "\n", 1, &n, NULL);
401			return 0;
402			}
403
404
405			/* Initialize the given passphrase callback @cb with the
406			used gpgme context @ctx, the command @cmd and a title
407			@title for the dialog. */
408			void
409			set_gpg_passphrase_cb (passphrase_cb_s *cb, gpgme_ctx_t ctx,
410			int cmd, HWND hwnd, const char *title)
411			{
412			memset (cb, 0, sizeof *cb);
413			cb->gpg_cmd = cmd;
414			cb->bad_pwd = 0;
415			cb->is_card = 0;
416			cb->cancel = 0;
417			cb->hwnd = hwnd;
418			cb->pwd_init = 1;
419			free_if_alloc (cb->title);
420			cb->title = m_strdup (title);
421			if (!cb->title)
422			BUG (NULL);
423			gpgme_set_passphrase_cb (ctx, passphrase_cb, cb);
424			cb->gpg = ctx;
425			}
426
427
428			/* Release a passphrase callback @ctx. */
429			void
430			release_gpg_passphrase_cb (passphrase_cb_s *ctx)
431			{
432			gpgme_recipient_t r, n;
433
434			if (!ctx)
435			return;
436			sfree_if_alloc (ctx->pwd);
437			free_if_alloc (ctx->title);
438			r = ctx->recipients;
439			while (r) {
440			n = r->next;
441			safe_free (r->keyid);
442			safe_free (r);
443			r = n;
444			}
445			}
446
447
448			/* Simple check to measure passphrase (@pass) quality.
449			Return value: 0 on success. */
450			int
451			check_passwd_quality (const char *pass, int strict)
452			{
453			int i, nd=0, nc=0, n;
454
455			n = strlen (pass);
456			if (n < 8)
457			return -1;
458
459			for (i=0; i < n; i++) {
460			if (isdigit (pass[i]))
461			nd++;
462			if (isalpha (pass[i]))
463			nc++;
464			}
465
466			/* check that the passphrase contains letters and numbers. */
467			if (nd == n \|\| nc == n)
468			return -1;
469
470			return 0;
471			}