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);
        SetDlgItemText (dlg, IDCANCEL, _("&Cancel"));
        SetDlgItemText (dlg, IDC_DECRYPT_HIDE, _("&Hide Typing"));
        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) {
            SetDlgItemText (dlg, IDC_DECRYPT_SIGN_HIDE, _("&Hide Typing"));
            CheckDlgButton (dlg, IDC_DECRYPT_SIGN_HIDE, BST_CHECKED);
        }
        /* Because it depends on the order the keys are stored in the
           keyring whether res->recipients is complete or not, we also
           support that the recipients were externally extracted and then
           we use this list. */
        if (c->recipients)
            recip = c->recipients; /* recipients were already extracted. */
        else {
            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 = recip; r; r = r->next) {
                get_pubkey (r->keyid, &key);
                if (key) {
                    gpgme_user_id_t u = key->uids;
                    char *uid;

                    id = u->name;
                    if (!id)
                        id = _("Invalid User ID");
                    uid = utf8_to_wincp (id, strlen (id));
                    n = 32+strlen (uid)+1+4+strlen (r->keyid)+1;
                    if (u->email)
                        n += strlen (u->email)+1;
                    info = new char [n+1];
                    if (!info)
                        BUG (NULL);
                    if (!u->email || strlen (u->email) < 1)
                        sprintf (info, "%s (%s, 0x%s)", uid,
                                 get_key_pubalgo (r->pubkey_algo), r->keyid+8);
                    else
                        sprintf (info, "%s <%s> (%s, 0x%s)", uid, u->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);
        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	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			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	twoaday	77	static passphrase_cb_s *c;
69			gpgme_decrypt_result_t res=NULL;
70			gpgme_sign_result_t res_sig=NULL;
71	werner	36	gpgme_key_t key;
72	twoaday	69	gpgme_recipient_t recip=NULL, r;
73			void *item;
74	werner	36	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	twoaday	105	SetDlgItemText (dlg, IDCANCEL, _("&Cancel"));
84	twoaday	85	SetDlgItemText (dlg, IDC_DECRYPT_HIDE, _("&Hide Typing"));
85	werner	36	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	twoaday	95	else if (c->gpg_cmd == GPG_CMD_SIGN) {
92			SetDlgItemText (dlg, IDC_DECRYPT_SIGN_HIDE, _("&Hide Typing"));
93	werner	36	CheckDlgButton (dlg, IDC_DECRYPT_SIGN_HIDE, BST_CHECKED);
94	twoaday	95	}
95	twoaday	179	/* Because it depends on the order the keys are stored in the
96			keyring whether res->recipients is complete or not, we also
97			support that the recipients were externally extracted and then
98			we use this list. */
99	werner	36	if (c->recipients)
100			recip = c->recipients; /* recipients were already extracted. */
101			else {
102			res = gpgme_op_decrypt_result (c->gpg);
103			if (res && res->recipients)
104			recip = res->recipients;
105			}
106			if (recip != NULL && c->gpg_cmd == GPG_CMD_DECRYPT) {
107	twoaday	179	for (r = recip; r; r = r->next) {
108	werner	36	get_pubkey (r->keyid, &key);
109			if (key) {
110	twoaday	160	gpgme_user_id_t u = key->uids;
111	werner	36	char *uid;
112	twoaday	160
113			id = u->name;
114	werner	36	if (!id)
115			id = _("Invalid User ID");
116			uid = utf8_to_wincp (id, strlen (id));
117	twoaday	160	n = 32+strlen (uid)+1+4+strlen (r->keyid)+1;
118			if (u->email)
119			n += strlen (u->email)+1;
120			info = new char [n+1];
121	werner	36	if (!info)
122			BUG (NULL);
123	twoaday	160	if (!u->email \|\| strlen (u->email) < 1)
124			sprintf (info, "%s (%s, 0x%s)", uid,
125			get_key_pubalgo (r->pubkey_algo), r->keyid+8);
126			else
127			sprintf (info, "%s <%s> (%s, 0x%s)", uid, u->email,
128			get_key_pubalgo (r->pubkey_algo), r->keyid+8);
129	werner	36	free (uid);
130			}
131			else {
132			info = new char [32 + strlen (r->keyid)+1 + 4];
133			if (!info)
134			BUG (NULL);
135			sprintf (info, _("Unknown key ID (%s, 0x%s)"),
136			get_key_pubalgo (r->pubkey_algo), r->keyid+8);
137			}
138			listbox_add_string (GetDlgItem (dlg, IDC_DECRYPT_LIST), info);
139			free_if_alloc (info);
140			}
141			}
142			else if (c->gpg_cmd == GPG_CMD_DECRYPT)
143			EnableWindow (GetDlgItem (dlg, IDC_DECRYPT_LIST), FALSE);
144			SetDlgItemText (dlg, c->gpg_cmd == GPG_CMD_DECRYPT?
145			IDC_DECRYPT_PWDINFO : IDC_DECRYPT_SIGN_PWDINFO,
146			c->bad_pwd? _("Bad passphrase; Enter passphrase again") :
147			_("Please enter your passphrase"));
148			if (c->gpg_cmd == GPG_CMD_DECRYPT) {
149			SetFocus (GetDlgItem (dlg, IDC_DECRYPT_PWD));
150			if (res && !res->recipients) {
151			const char *s = _("Symmetric encryption.\n"
152			"%s encrypted data.");
153			const char *alg = get_symkey_algo (c->sym.sym_algo);
154			info = new char[strlen (s) + strlen (alg) + 2];
155			if (!info)
156			BUG (NULL);
157			sprintf (info, s, alg);
158			SetDlgItemText (dlg, IDC_DECRYPT_MSG, info);
159			free_if_alloc (info);
160			}
161			else
162			SetDlgItemText (dlg, IDC_DECRYPT_MSG, c->info);
163			}
164			else {
165			SetFocus( GetDlgItem (dlg, IDC_DECRYPT_SIGN_PWD));
166			SetDlgItemText (dlg, IDC_DECRYPT_SIGN_MSG, c->info);
167			}
168			center_window (dlg, NULL);
169			SetForegroundWindow (dlg);
170			return FALSE;
171
172			case WM_SYSCOMMAND:
173			if (LOWORD (wparam) == SC_CLOSE) {
174			SetDlgItemText (dlg, item_ctrl_id (c->gpg_cmd), "");
175			c->cancel = 1;
176			EndDialog (dlg, TRUE);
177			}
178			break;
179
180			case WM_COMMAND:
181			switch (HIWORD (wparam)) {
182			case BN_CLICKED:
183			if (LOWORD (wparam) == IDC_DECRYPT_HIDE
184			\|\| LOWORD (wparam) == IDC_DECRYPT_SIGN_HIDE) {
185			HWND hwnd;
186			int hide = IsDlgButtonChecked (dlg, item_ctrl_id2 (c->gpg_cmd));
187			hwnd = GetDlgItem (dlg, item_ctrl_id (c->gpg_cmd));
188			SendMessage (hwnd, EM_SETPASSWORDCHAR, hide? '*' : 0, 0);
189			SetFocus (hwnd);
190			}
191			}
192
193			switch (LOWORD (wparam)) {
194			case IDOK:
195			/* XXX: the item is even cached when the passphrase is not
196			correct, which means that the user needs to delete all
197			cached entries to continue. */
198			if (c->pwd)
199			burn_passphrase (&c->pwd);
200			n = item_get_text_length (dlg, item_ctrl_id (c->gpg_cmd));
201			if (!n) {
202			c->pwd = new char[2];
203			if (!c->pwd)
204			BUG (NULL);
205			strcpy (c->pwd, "");
206			}
207			else {
208			c->pwd = new char[n+2];
209			if (!c->pwd)
210			BUG (NULL);
211			GetDlgItemText (dlg, item_ctrl_id (c->gpg_cmd), c->pwd, n+1);
212			}
213			res = gpgme_op_decrypt_result (c->gpg);
214			if (!res)
215	twoaday	77	res_sig = gpgme_op_sign_result (c->gpg);
216			if (reg_prefs.cache_time > 0 && !c->is_card &&
217			(res \|\| res_sig)) {
218			if (agent_get_cache (c->keyid, &item))
219	werner	36	agent_unlock_cache_entry (&item);
220	twoaday	77	else
221	werner	36	agent_put_cache (c->keyid, c->pwd, reg_prefs.cache_time);
222			}
223			c->cancel = 0;
224			EndDialog (dlg, TRUE);
225			return TRUE;
226
227			case IDCANCEL:
228			SetDlgItemText (dlg, item_ctrl_id (c->gpg_cmd), "");
229			c->cancel = 1;
230			EndDialog (dlg, FALSE);
231			return FALSE;
232			}
233			break;
234			}
235
236			return FALSE;
237			}
238
239
240			/* Extract the main keyid from @pass_info.
241			Return value: long main keyid or NULL for an error. */
242			static const char*
243			parse_gpg_keyid (const char *pass_info)
244			{
245			static char keyid[16+1];
246
247			/* XXX: check for leading alpha-chars? */
248	twoaday	77	if (strlen (pass_info) < 16) {
249			log_debug ("parse_gpg_keyid: error '%s'\r\n", pass_info);
250	werner	36	return NULL;
251	twoaday	77	}
252	werner	36	/* the format of the desc buffer looks like this:
253			request_keyid[16] main_keyid[16] keytype[1] keylength[4]
254			we use the main keyid to use only one cache entry. */
255			strncpy (keyid, pass_info+17, 16);
256			keyid[16] = 0;
257			return keyid;
258			}
259
260
261			/* Parse the information in @uid_hint and @pass_info to generate
262			a input message for the user in @desc. */
263			static int
264			parse_gpg_description (const char uid_hint, const char pass_info,
265			char *desc, int size)
266			{
267			gpgme_pubkey_algo_t algo;
268			char usedkey[16+1];
269			char mainkey[16+1];
270			char uid, p;
271			int n=0;
272
273	twoaday	69	algo = (gpgme_pubkey_algo_t)0;
274	werner	36	/* Each uid_hint contains a long key-ID so it is at least 16 bytes. */
275			if (strlen (uid_hint) < 17) {
276			*desc = 0;
277	twoaday	77	log_debug ("parse_gpg_description: error '%s'\r\n", uid_hint);
278	werner	36	return -1;
279			}
280
281			while (p = strsep ((char**)&pass_info, " ")) {
282			switch (n++) {
283			case 0: strncpy (mainkey, p, 16); mainkey[16] = 0; break;
284			case 1: strncpy (usedkey, p, 16); usedkey[16] = 0; break;
285			case 2: algo = (gpgme_pubkey_algo_t)atol (p); break;
286			}
287			}
288			uid_hint += 16; /* skip keyid */
289			uid_hint += 1; /* space */
290
291			uid = utf8_to_wincp (uid_hint, strlen (uid_hint));
292
293			if (strcmp (usedkey, mainkey))
294			_snprintf (desc, size-1,
295			_("You need a passphrase to unlock the secret key for\n"
296			"user: \"%s\"\n"
297			"%s key, ID %s (main key ID %s)\n"),
298			uid, get_key_pubalgo (algo), usedkey+8, mainkey+8);
299			else if (!strcmp (usedkey, mainkey))
300			_snprintf (desc, size-1,
301			_("You need a passphrase to unlock the secret key for\n"
302			"user: \"%s\"\n"
303			"%s key, ID %s\n"),
304			uid, get_key_pubalgo (algo), usedkey+8);
305			free (uid);
306			return 0;
307			}
308
309
310			/* Extract the serial number from the card ID @id and return it. */
311			const char*
312			extract_serial_no (const char *id)
313			{
314			static char buf[8];
315			char *p;
316
317			p = strchr (id, '/');
318	twoaday	77	if (!p) {
319			log_debug ("extract_serial_no: error '%s'\r\n", id);
320	werner	36	return NULL;
321	twoaday	77	}
322	werner	36	strncpy (buf, id+(p-id)-6, 6);
323			return buf;
324			}
325
326
327			/* Passphrase callback with the ability to support caching. */
328			gpgme_error_t
329			passphrase_cb (void hook, const char uid_hint,
330			const char *passphrase_info,
331			int prev_was_bad, int fd)
332			{
333			passphrase_cb_s c = (passphrase_cb_s)hook;
334			HANDLE hd = (HANDLE)fd;
335			void *item;
336	twoaday	69	const char keyid=NULL, pass;
337	werner	36	DWORD n;
338	twoaday	77	int rc = 0;
339	werner	36
340	twoaday	77	if (!c) {
341			log_debug ("passphrase_cb: error '!c'\r\n");
342	werner	36	return gpg_error (GPG_ERR_INV_ARG);
343	twoaday	77	}
344	werner	36	c->bad_pwd = prev_was_bad? 1 : 0;
345			if (prev_was_bad && !c->cancel) {
346			if (c->pwd)
347			burn_passphrase (&c->pwd);
348			agent_del_cache (c->keyid);
349			c->pwd_init = 1;
350			}
351
352			if (passphrase_info) {
353			if (strlen (passphrase_info) < 16 &&
354			!strstr (passphrase_info, "OPENPGP")) {
355			/* assume symetric encryption. */
356	twoaday	69	int pos=2;
357	werner	36	c->sym.sym_algo = atoi (passphrase_info);
358			if (c->sym.sym_algo > 9)
359	twoaday	69	pos++;
360	werner	36	/* XXX: be more strict. */
361	twoaday	69	c->sym.s2k_mode = atoi (passphrase_info+pos);
362			c->sym.s2k_hash = atoi (passphrase_info+pos+2);
363	werner	36	}
364
365			keyid = parse_gpg_keyid (passphrase_info);
366	twoaday	77	pass = agent_get_cache (keyid+8, &item);
367	werner	36	if (pass) {
368			agent_unlock_cache_entry (&item);
369			c->pwd_init = 0;
370			if (!WriteFile (hd, pass, strlen (pass), &n, NULL))
371			log_debug ("passphrase_cb: WriteFile() failed ec=%d\n", w32_errno);
372			if (!WriteFile (hd, "\n", 1, &n, NULL))
373			log_debug ("passphrase_cb: WriteFile() failed ec=%d\n", w32_errno);
374			return 0;
375			}
376			}
377
378			if (c->pwd_init) {
379			if (keyid && strlen (keyid) == 16)
380			strcpy (c->keyid, keyid+8);
381
382			/* if @passphrase_info contains 'OPENPGP' we assume a smart card
383			has been used. */
384			if (strstr (passphrase_info, "OPENPGP")) {
385			const char *s=passphrase_info;
386			while (s && s && s != 'D')
387			s++;
388			_snprintf (c->info, sizeof c->info-1,
389			_("Please enter the PIN to unlock your secret card key\n"
390			"Card: %s"), extract_serial_no (s));
391			c->is_card = 1;
392			}
393			else if (uid_hint)
394			parse_gpg_description (uid_hint, passphrase_info,
395			c->info, sizeof c->info - 1);
396			if (c->gpg_cmd == GPG_CMD_DECRYPT) {
397			rc = DialogBoxParam (glob_hinst, (LPCSTR)IDD_WINPT_DECRYPT,
398			(HWND)c->hwnd, passphrase_callback_proc,
399			(LPARAM)c);
400			}
401			else if (c->gpg_cmd == GPG_CMD_SIGN) {
402			rc = DialogBoxParam (glob_hinst, (LPCSTR)IDD_WINPT_DECRYPT_SIGN,
403			(HWND)c->hwnd, passphrase_callback_proc,
404			(LPARAM)c);
405			}
406			if (rc == -1) {
407			if (!WriteFile (hd, "\n", 1, &n, NULL))
408			log_debug ("passphrase_cb: WriteFile() failed ec=%d\n", w32_errno);
409			return 0;
410			}
411			c->pwd_init = 0;
412			}
413			if (c->cancel) {
414			if (!WriteFile (hd, "\n", 1, &n, NULL))
415			log_debug ("passphrase_cb: WriteFile() failed ec=%d\n", w32_errno);
416			return 0;
417			}
418
419	twoaday	77	if (!WriteFile (hd, c->pwd, strlen (c->pwd), &n, NULL))
420			log_debug ("passphrase_cb: WriteFile() failed ec=%d\n", w32_errno);
421			if (!WriteFile (hd, "\n", 1, &n, NULL))
422			log_debug ("passphrase_cb: WriteFile() failed ec=%d\n", w32_errno);
423	werner	36	return 0;
424			}
425
426
427			/* Initialize the given passphrase callback @cb with the
428			used gpgme context @ctx, the command @cmd and a title
429			@title for the dialog. */
430			void
431			set_gpg_passphrase_cb (passphrase_cb_s *cb, gpgme_ctx_t ctx,
432			int cmd, HWND hwnd, const char *title)
433			{
434			memset (cb, 0, sizeof *cb);
435			cb->gpg_cmd = cmd;
436			cb->bad_pwd = 0;
437			cb->is_card = 0;
438			cb->cancel = 0;
439			cb->hwnd = hwnd;
440			cb->pwd_init = 1;
441			free_if_alloc (cb->title);
442			cb->title = m_strdup (title);
443			if (!cb->title)
444			BUG (NULL);
445			gpgme_set_passphrase_cb (ctx, passphrase_cb, cb);
446			cb->gpg = ctx;
447			}
448
449
450			/* Release a passphrase callback @ctx. */
451			void
452			release_gpg_passphrase_cb (passphrase_cb_s *ctx)
453			{
454			gpgme_recipient_t r, n;
455
456			if (!ctx)
457			return;
458			sfree_if_alloc (ctx->pwd);
459			free_if_alloc (ctx->title);
460			r = ctx->recipients;
461			while (r) {
462			n = r->next;
463			safe_free (r->keyid);
464			safe_free (r);
465			r = n;
466			}
467			}
468
469
470			/* Simple check to measure passphrase (@pass) quality.
471			Return value: 0 on success. */
472			int
473			check_passwd_quality (const char *pass, int strict)
474			{
475			int i, nd=0, nc=0, n;
476
477			n = strlen (pass);
478			if (n < 8)
479			return -1;
480
481			for (i=0; i < n; i++) {
482			if (isdigit (pass[i]))
483			nd++;
484			if (isalpha (pass[i]))
485			nc++;
486			}
487
488			/* check that the passphrase contains letters and numbers. */
489			if (nd == n \|\| nc == n)
490			return -1;
491
492			return 0;
493			}