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_ACTIVATE:
        safe_edit_control_init (dlg, item_ctrl_id (c->gpg_cmd));
        break;

    case WM_DESTROY:
        safe_edit_control_free (dlg, item_ctrl_id (c->gpg_cmd));
        break;

    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_native (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);
                    SafeGetDlgItemText (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_native (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_ACTIVATE:
80	safe_edit_control_init (dlg, item_ctrl_id (c->gpg_cmd));
81	break;
82
83	case WM_DESTROY:
84	safe_edit_control_free (dlg, item_ctrl_id (c->gpg_cmd));
85	break;
86
87	case WM_INITDIALOG:
88	c = (passphrase_cb_s *)lparam;
89	if (!c)
90	BUG (0);
91	SetDlgItemText (dlg, IDCANCEL, _("&Cancel"));
92	SetDlgItemText (dlg, IDC_DECRYPT_HIDE, _("&Hide Typing"));
93	SetWindowText (dlg, c->title);
94	if (c->gpg_cmd == GPG_CMD_DECRYPT) {
95	SetDlgItemText (dlg, IDC_DECRYPT_LISTINF,
96	_("Encrypted with the following public key(s)"));
97	CheckDlgButton (dlg, IDC_DECRYPT_HIDE, BST_CHECKED);
98	}
99	else if (c->gpg_cmd == GPG_CMD_SIGN) {
100	SetDlgItemText (dlg, IDC_DECRYPT_SIGN_HIDE, _("&Hide Typing"));
101	CheckDlgButton (dlg, IDC_DECRYPT_SIGN_HIDE, BST_CHECKED);
102	}
103	/* Because it depends on the order the keys are stored in the
104	keyring whether res->recipients is complete or not, we also
105	support that the recipients were externally extracted and then
106	we use this list. */
107	if (c->recipients)
108	recip = c->recipients; /* recipients were already extracted. */
109	else {
110	res = gpgme_op_decrypt_result (c->gpg);
111	if (res && res->recipients)
112	recip = res->recipients;
113	}
114	if (recip != NULL && c->gpg_cmd == GPG_CMD_DECRYPT) {
115	for (r = recip; r; r = r->next) {
116	get_pubkey (r->keyid, &key);
117	if (key) {
118	gpgme_user_id_t u = key->uids;
119	char *uid;
120
121	id = u->name;
122	if (!id)
123	id = _("Invalid User ID");
124	uid = utf8_to_native (id);
125	n = 32+strlen (uid)+1+4+strlen (r->keyid)+1;
126	if (u->email)
127	n += strlen (u->email)+1;
128	info = new char [n+1];
129	if (!info)
130	BUG (NULL);
131	if (!u->email \|\| strlen (u->email) < 1)
132	sprintf (info, "%s (%s, 0x%s)", uid,
133	get_key_pubalgo (r->pubkey_algo), r->keyid+8);
134	else
135	sprintf (info, "%s <%s> (%s, 0x%s)", uid, u->email,
136	get_key_pubalgo (r->pubkey_algo), r->keyid+8);
137	free (uid);
138	}
139	else {
140	info = new char [32 + strlen (r->keyid)+1 + 4];
141	if (!info)
142	BUG (NULL);
143	sprintf (info, _("Unknown key ID (%s, 0x%s)"),
144	get_key_pubalgo (r->pubkey_algo), r->keyid+8);
145	}
146	listbox_add_string (GetDlgItem (dlg, IDC_DECRYPT_LIST), info);
147	free_if_alloc (info);
148	}
149	}
150	else if (c->gpg_cmd == GPG_CMD_DECRYPT)
151	EnableWindow (GetDlgItem (dlg, IDC_DECRYPT_LIST), FALSE);
152	SetDlgItemText (dlg, c->gpg_cmd == GPG_CMD_DECRYPT?
153	IDC_DECRYPT_PWDINFO : IDC_DECRYPT_SIGN_PWDINFO,
154	c->bad_pwd? _("Bad passphrase; Enter passphrase again") :
155	_("Please enter your passphrase"));
156	if (c->gpg_cmd == GPG_CMD_DECRYPT) {
157	SetFocus (GetDlgItem (dlg, IDC_DECRYPT_PWD));
158	if (res && !res->recipients) {
159	const char *s = _("Symmetric encryption.\n"
160	"%s encrypted data.");
161	const char *alg = get_symkey_algo (c->sym.sym_algo);
162	info = new char[strlen (s) + strlen (alg) + 2];
163	if (!info)
164	BUG (NULL);
165	sprintf (info, s, alg);
166	SetDlgItemText (dlg, IDC_DECRYPT_MSG, info);
167	free_if_alloc (info);
168	}
169	else
170	SetDlgItemText (dlg, IDC_DECRYPT_MSG, c->info);
171	}
172	else {
173	SetFocus( GetDlgItem (dlg, IDC_DECRYPT_SIGN_PWD));
174	SetDlgItemText (dlg, IDC_DECRYPT_SIGN_MSG, c->info);
175	}
176	center_window (dlg, NULL);
177	SetForegroundWindow (dlg);
178	return FALSE;
179
180	case WM_SYSCOMMAND:
181	if (LOWORD (wparam) == SC_CLOSE) {
182	SetDlgItemText (dlg, item_ctrl_id (c->gpg_cmd), "");
183	c->cancel = 1;
184	EndDialog (dlg, TRUE);
185	}
186	break;
187
188	case WM_COMMAND:
189	switch (HIWORD (wparam)) {
190	case BN_CLICKED:
191	if (LOWORD (wparam) == IDC_DECRYPT_HIDE
192	\|\| LOWORD (wparam) == IDC_DECRYPT_SIGN_HIDE) {
193	HWND hwnd;
194	int hide = IsDlgButtonChecked (dlg, item_ctrl_id2 (c->gpg_cmd));
195	hwnd = GetDlgItem (dlg, item_ctrl_id (c->gpg_cmd));
196	SendMessage (hwnd, EM_SETPASSWORDCHAR, hide? '*' : 0, 0);
197	SetFocus (hwnd);
198	}
199	}
200
201	switch (LOWORD (wparam)) {
202	case IDOK:
203	/* XXX: the item is even cached when the passphrase is not
204	correct, which means that the user needs to delete all
205	cached entries to continue. */
206	if (c->pwd)
207	burn_passphrase (&c->pwd);
208	n = item_get_text_length (dlg, item_ctrl_id (c->gpg_cmd));
209	if (!n) {
210	c->pwd = new char[2];
211	if (!c->pwd)
212	BUG (NULL);
213	strcpy (c->pwd, "");
214	}
215	else {
216	c->pwd = new char[n+2];
217	if (!c->pwd)
218	BUG (NULL);
219	SafeGetDlgItemText (dlg, item_ctrl_id (c->gpg_cmd),
220	c->pwd, n+1);
221	}
222	res = gpgme_op_decrypt_result (c->gpg);
223	if (!res)
224	res_sig = gpgme_op_sign_result (c->gpg);
225	if (reg_prefs.cache_time > 0 && !c->is_card &&
226	(res \|\| res_sig)) {
227	if (agent_get_cache (c->keyid, &item))
228	agent_unlock_cache_entry (&item);
229	else
230	agent_put_cache (c->keyid, c->pwd, reg_prefs.cache_time);
231	}
232	c->cancel = 0;
233	EndDialog (dlg, TRUE);
234	return TRUE;
235
236	case IDCANCEL:
237	SetDlgItemText (dlg, item_ctrl_id (c->gpg_cmd), "");
238	c->cancel = 1;
239	EndDialog (dlg, FALSE);
240	return FALSE;
241	}
242	break;
243	}
244
245	return FALSE;
246	}
247
248
249	/* Extract the main keyid from @pass_info.
250	Return value: long main keyid or NULL for an error. */
251	static const char*
252	parse_gpg_keyid (const char *pass_info)
253	{
254	static char keyid[16+1];
255
256	/* XXX: check for leading alpha-chars? */
257	if (strlen (pass_info) < 16) {
258	log_debug ("parse_gpg_keyid: error '%s'\r\n", pass_info);
259	return NULL;
260	}
261	/* the format of the desc buffer looks like this:
262	request_keyid[16] main_keyid[16] keytype[1] keylength[4]
263	we use the main keyid to use only one cache entry. */
264	strncpy (keyid, pass_info+17, 16);
265	keyid[16] = 0;
266	return keyid;
267	}
268
269
270	/* Parse the information in @uid_hint and @pass_info to generate
271	a input message for the user in @desc. */
272	static int
273	parse_gpg_description (const char uid_hint, const char pass_info,
274	char *desc, int size)
275	{
276	gpgme_pubkey_algo_t algo;
277	char usedkey[16+1];
278	char mainkey[16+1];
279	char uid, p;
280	int n=0;
281
282	algo = (gpgme_pubkey_algo_t)0;
283	/* Each uid_hint contains a long key-ID so it is at least 16 bytes. */
284	if (strlen (uid_hint) < 17) {
285	*desc = 0;
286	log_debug ("parse_gpg_description: error '%s'\r\n", uid_hint);
287	return -1;
288	}
289
290	while (p = strsep ((char**)&pass_info, " ")) {
291	switch (n++) {
292	case 0: strncpy (mainkey, p, 16); mainkey[16] = 0; break;
293	case 1: strncpy (usedkey, p, 16); usedkey[16] = 0; break;
294	case 2: algo = (gpgme_pubkey_algo_t)atol (p); break;
295	}
296	}
297	uid_hint += 16; /* skip keyid */
298	uid_hint += 1; /* space */
299
300	uid = utf8_to_native (uid_hint);
301
302	if (strcmp (usedkey, mainkey))
303	_snprintf (desc, size-1,
304	_("You need a passphrase to unlock the secret key for\n"
305	"user: \"%s\"\n"
306	"%s key, ID %s (main key ID %s)\n"),
307	uid, get_key_pubalgo (algo), usedkey+8, mainkey+8);
308	else if (!strcmp (usedkey, mainkey))
309	_snprintf (desc, size-1,
310	_("You need a passphrase to unlock the secret key for\n"
311	"user: \"%s\"\n"
312	"%s key, ID %s\n"),
313	uid, get_key_pubalgo (algo), usedkey+8);
314	free (uid);
315	return 0;
316	}
317
318
319	/* Extract the serial number from the card ID @id and return it. */
320	const char*
321	extract_serial_no (const char *id)
322	{
323	static char buf[8];
324	char *p;
325
326	p = strchr (id, '/');
327	if (!p) {
328	log_debug ("extract_serial_no: error '%s'\r\n", id);
329	return NULL;
330	}
331	strncpy (buf, id+(p-id)-6, 6);
332	return buf;
333	}
334
335
336	/* Passphrase callback with the ability to support caching. */
337	gpgme_error_t
338	passphrase_cb (void hook, const char uid_hint,
339	const char *passphrase_info,
340	int prev_was_bad, int fd)
341	{
342	passphrase_cb_s c = (passphrase_cb_s)hook;
343	HANDLE hd = (HANDLE)fd;
344	void *item;
345	const char keyid=NULL, pass;
346	DWORD n;
347	int rc = 0;
348
349	if (!c) {
350	log_debug ("passphrase_cb: error '!c'\r\n");
351	return gpg_error (GPG_ERR_INV_ARG);
352	}
353	c->bad_pwd = prev_was_bad? 1 : 0;
354	if (prev_was_bad && !c->cancel) {
355	if (c->pwd)
356	burn_passphrase (&c->pwd);
357	agent_del_cache (c->keyid);
358	c->pwd_init = 1;
359	}
360
361	if (passphrase_info) {
362	if (strlen (passphrase_info) < 16 &&
363	!strstr (passphrase_info, "OPENPGP")) {
364	/* assume symetric encryption. */
365	int pos=2;
366	c->sym.sym_algo = atoi (passphrase_info);
367	if (c->sym.sym_algo > 9)
368	pos++;
369	/* XXX: be more strict. */
370	c->sym.s2k_mode = atoi (passphrase_info+pos);
371	c->sym.s2k_hash = atoi (passphrase_info+pos+2);
372	}
373
374	keyid = parse_gpg_keyid (passphrase_info);
375	pass = agent_get_cache (keyid+8, &item);
376	if (pass) {
377	agent_unlock_cache_entry (&item);
378	c->pwd_init = 0;
379	if (!WriteFile (hd, pass, strlen (pass), &n, NULL))
380	log_debug ("passphrase_cb: WriteFile() failed ec=%d\n", w32_errno);
381	if (!WriteFile (hd, "\n", 1, &n, NULL))
382	log_debug ("passphrase_cb: WriteFile() failed ec=%d\n", w32_errno);
383	return 0;
384	}
385	}
386
387	if (c->pwd_init) {
388	if (keyid && strlen (keyid) == 16)
389	strcpy (c->keyid, keyid+8);
390
391	/* if @passphrase_info contains 'OPENPGP' we assume a smart card
392	has been used. */
393	if (strstr (passphrase_info, "OPENPGP")) {
394	const char *s=passphrase_info;
395	while (s && s && s != 'D')
396	s++;
397	_snprintf (c->info, sizeof c->info-1,
398	_("Please enter the PIN to unlock your secret card key\n"
399	"Card: %s"), extract_serial_no (s));
400	c->is_card = 1;
401	}
402	else if (uid_hint)
403	parse_gpg_description (uid_hint, passphrase_info,
404	c->info, sizeof (c->info) - 1);
405	if (c->gpg_cmd == GPG_CMD_DECRYPT) {
406	rc = DialogBoxParam (glob_hinst, (LPCSTR)IDD_WINPT_DECRYPT,
407	(HWND)c->hwnd, passphrase_callback_proc,
408	(LPARAM)c);
409	}
410	else if (c->gpg_cmd == GPG_CMD_SIGN) {
411	rc = DialogBoxParam (glob_hinst, (LPCSTR)IDD_WINPT_DECRYPT_SIGN,
412	(HWND)c->hwnd, passphrase_callback_proc,
413	(LPARAM)c);
414	}
415	if (rc == -1) {
416	if (!WriteFile (hd, "\n", 1, &n, NULL))
417	log_debug ("passphrase_cb: WriteFile() failed ec=%d\n", w32_errno);
418	return 0;
419	}
420	c->pwd_init = 0;
421	}
422	if (c->cancel) {
423	if (!WriteFile (hd, "\n", 1, &n, NULL))
424	log_debug ("passphrase_cb: WriteFile() failed ec=%d\n", w32_errno);
425	return 0;
426	}
427
428	if (!WriteFile (hd, c->pwd, strlen (c->pwd), &n, NULL))
429	log_debug ("passphrase_cb: WriteFile() failed ec=%d\n", w32_errno);
430	if (!WriteFile (hd, "\n", 1, &n, NULL))
431	log_debug ("passphrase_cb: WriteFile() failed ec=%d\n", w32_errno);
432	return 0;
433	}
434
435
436	/* Initialize the given passphrase callback @cb with the
437	used gpgme context @ctx, the command @cmd and a title
438	@title for the dialog. */
439	void
440	set_gpg_passphrase_cb (passphrase_cb_s *cb, gpgme_ctx_t ctx,
441	int cmd, HWND hwnd, const char *title)
442	{
443	memset (cb, 0, sizeof *cb);
444	cb->gpg_cmd = cmd;
445	cb->bad_pwd = 0;
446	cb->is_card = 0;
447	cb->cancel = 0;
448	cb->hwnd = hwnd;
449	cb->pwd_init = 1;
450	free_if_alloc (cb->title);
451	cb->title = m_strdup (title);
452	if (!cb->title)
453	BUG (NULL);
454	gpgme_set_passphrase_cb (ctx, passphrase_cb, cb);
455	cb->gpg = ctx;
456	}
457
458
459	/* Release a passphrase callback @ctx. */
460	void
461	release_gpg_passphrase_cb (passphrase_cb_s *ctx)
462	{
463	gpgme_recipient_t r, n;
464
465	if (!ctx)
466	return;
467	sfree_if_alloc (ctx->pwd);
468	free_if_alloc (ctx->title);
469	r = ctx->recipients;
470	while (r) {
471	n = r->next;
472	safe_free (r->keyid);
473	safe_free (r);
474	r = n;
475	}
476	}
477
478
479	/* Simple check to measure passphrase (@pass) quality.
480	Return value: 0 on success. */
481	int
482	check_passwd_quality (const char *pass, int strict)
483	{
484	int i, nd=0, nc=0, n;
485
486	n = strlen (pass);
487	if (n < 8)
488	return -1;
489
490	for (i=0; i < n; i++) {
491	if (isdigit (pass[i]))
492	nd++;
493	if (isalpha (pass[i]))
494	nc++;
495	}
496
497	/* check that the passphrase contains letters and numbers. */
498	if (nd == n \|\| nc == n)
499	return -1;
500
501	return 0;
502	}