trunk/Src/wptPassphraseCB.cpp

/* wptPassphraseCB.cpp - GPGME Passphrase Callback
 *      Copyright (C) 2001, 2002, 2003, 2005, 2006 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 "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)


void ListBox_AddString_utf8 (HWND lb, const char *txt);

/* 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;

                    id = u->name;
                    if (!id)
                        id = _("Invalid User ID");
                    n = 32+strlen (id)+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)", id,
                                 get_key_pubalgo (r->pubkey_algo), r->keyid+8);
                    else
                        sprintf (info, "%s <%s> (%s, 0x%s)", id, u->email,
                                 get_key_pubalgo (r->pubkey_algo), r->keyid+8);
                }
                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_AddString_utf8 (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_utf8 (dlg, IDC_DECRYPT_MSG, c->info);
        }
        else {
            SetFocus (GetDlgItem (dlg, IDC_DECRYPT_SIGN_PWD));
            SetDlgItemText_utf8 (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 *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 */

    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_hint, 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_hint, get_key_pubalgo (algo), usedkey+8);
    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, 2006 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 "wptErrors.h"
38	#include "wptTypes.h"
39	#include "wptKeylist.h"
40	#include "wptAgent.h"
41	#include "wptRegistry.h"
42
43	const char* get_symkey_algo (int algo);
44
45	#define item_ctrl_id(cmd) \
46	((cmd) == GPG_CMD_DECRYPT? IDC_DECRYPT_PWD : IDC_DECRYPT_SIGN_PWD)
47
48	#define item_ctrl_id2(cmd) \
49	((cmd) == GPG_CMD_DECRYPT? IDC_DECRYPT_HIDE : IDC_DECRYPT_SIGN_HIDE)
50
51
52	void ListBox_AddString_utf8 (HWND lb, const char *txt);
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=NULL;
71	gpgme_sign_result_t res_sig=NULL;
72	gpgme_key_t key;
73	gpgme_recipient_t recip=NULL, r;
74	void *item;
75	const char *id;
76	char *info;
77	int n;
78
79	switch (msg) {
80	case WM_ACTIVATE:
81	safe_edit_control_init (dlg, item_ctrl_id (c->gpg_cmd));
82	break;
83
84	case WM_DESTROY:
85	safe_edit_control_free (dlg, item_ctrl_id (c->gpg_cmd));
86	break;
87
88	case WM_INITDIALOG:
89	c = (passphrase_cb_s *)lparam;
90	if (!c)
91	BUG (0);
92	SetDlgItemText (dlg, IDCANCEL, _("&Cancel"));
93	SetDlgItemText (dlg, IDC_DECRYPT_HIDE, _("&Hide Typing"));
94	SetWindowText (dlg, c->title);
95	if (c->gpg_cmd == GPG_CMD_DECRYPT) {
96	SetDlgItemText (dlg, IDC_DECRYPT_LISTINF,
97	_("Encrypted with the following public key(s)"));
98	CheckDlgButton (dlg, IDC_DECRYPT_HIDE, BST_CHECKED);
99	}
100	else if (c->gpg_cmd == GPG_CMD_SIGN) {
101	SetDlgItemText (dlg, IDC_DECRYPT_SIGN_HIDE, _("&Hide Typing"));
102	CheckDlgButton (dlg, IDC_DECRYPT_SIGN_HIDE, BST_CHECKED);
103	}
104	/* Because it depends on the order the keys are stored in the
105	keyring whether res->recipients is complete or not, we also
106	support that the recipients were externally extracted and then
107	we use this list. */
108	if (c->recipients)
109	recip = c->recipients; /* recipients were already extracted. */
110	else {
111	res = gpgme_op_decrypt_result (c->gpg);
112	if (res && res->recipients)
113	recip = res->recipients;
114	}
115	if (recip != NULL && c->gpg_cmd == GPG_CMD_DECRYPT) {
116	for (r = recip; r; r = r->next) {
117	get_pubkey (r->keyid, &key);
118	if (key) {
119	gpgme_user_id_t u = key->uids;
120
121	id = u->name;
122	if (!id)
123	id = _("Invalid User ID");
124	n = 32+strlen (id)+1+4+strlen (r->keyid)+1;
125	if (u->email)
126	n += strlen (u->email)+1;
127	info = new char [n+1];
128	if (!info)
129	BUG (NULL);
130	if (!u->email \|\| strlen (u->email) < 1)
131	sprintf (info, "%s (%s, 0x%s)", id,
132	get_key_pubalgo (r->pubkey_algo), r->keyid+8);
133	else
134	sprintf (info, "%s <%s> (%s, 0x%s)", id, u->email,
135	get_key_pubalgo (r->pubkey_algo), r->keyid+8);
136	}
137	else {
138	info = new char [32 + strlen (r->keyid)+1 + 4];
139	if (!info)
140	BUG (NULL);
141	sprintf (info, _("Unknown key ID (%s, 0x%s)"),
142	get_key_pubalgo (r->pubkey_algo), r->keyid+8);
143	}
144	ListBox_AddString_utf8 (GetDlgItem (dlg, IDC_DECRYPT_LIST), info);
145	free_if_alloc (info);
146	}
147	}
148	else if (c->gpg_cmd == GPG_CMD_DECRYPT)
149	EnableWindow (GetDlgItem (dlg, IDC_DECRYPT_LIST), FALSE);
150	SetDlgItemText (dlg, c->gpg_cmd == GPG_CMD_DECRYPT?
151	IDC_DECRYPT_PWDINFO : IDC_DECRYPT_SIGN_PWDINFO,
152	c->bad_pwd? _("Bad passphrase; Enter passphrase again") :
153	_("Please enter your passphrase"));
154	if (c->gpg_cmd == GPG_CMD_DECRYPT) {
155	SetFocus (GetDlgItem (dlg, IDC_DECRYPT_PWD));
156	if (res && !res->recipients) {
157	const char *s = _("Symmetric encryption.\n"
158	"%s encrypted data.");
159	const char *alg = get_symkey_algo (c->sym.sym_algo);
160	info = new char[strlen (s) + strlen (alg) + 2];
161	if (!info)
162	BUG (NULL);
163	sprintf (info, s, alg);
164	SetDlgItemText (dlg, IDC_DECRYPT_MSG, info);
165	free_if_alloc (info);
166	}
167	else
168	SetDlgItemText_utf8 (dlg, IDC_DECRYPT_MSG, c->info);
169	}
170	else {
171	SetFocus (GetDlgItem (dlg, IDC_DECRYPT_SIGN_PWD));
172	SetDlgItemText_utf8 (dlg, IDC_DECRYPT_SIGN_MSG, c->info);
173	}
174	center_window (dlg, NULL);
175	SetForegroundWindow (dlg);
176	return FALSE;
177
178	case WM_SYSCOMMAND:
179	if (LOWORD (wparam) == SC_CLOSE) {
180	SetDlgItemText (dlg, item_ctrl_id (c->gpg_cmd), "");
181	c->cancel = 1;
182	EndDialog (dlg, TRUE);
183	}
184	break;
185
186	case WM_COMMAND:
187	switch (HIWORD (wparam)) {
188	case BN_CLICKED:
189	if (LOWORD (wparam) == IDC_DECRYPT_HIDE
190	\|\| LOWORD (wparam) == IDC_DECRYPT_SIGN_HIDE) {
191	HWND hwnd;
192	int hide = IsDlgButtonChecked (dlg, item_ctrl_id2 (c->gpg_cmd));
193	hwnd = GetDlgItem (dlg, item_ctrl_id (c->gpg_cmd));
194	SendMessage (hwnd, EM_SETPASSWORDCHAR, hide? '*' : 0, 0);
195	SetFocus (hwnd);
196	}
197	}
198
199	switch (LOWORD (wparam)) {
200	case IDOK:
201	/* XXX: the item is even cached when the passphrase is not
202	correct, which means that the user needs to delete all
203	cached entries to continue. */
204	if (c->pwd)
205	burn_passphrase (&c->pwd);
206	n = item_get_text_length (dlg, item_ctrl_id (c->gpg_cmd));
207	if (!n) {
208	c->pwd = new char[2];
209	if (!c->pwd)
210	BUG (NULL);
211	strcpy (c->pwd, "");
212	}
213	else {
214	c->pwd = new char[n+2];
215	if (!c->pwd)
216	BUG (NULL);
217	SafeGetDlgItemText (dlg, item_ctrl_id (c->gpg_cmd),
218	c->pwd, n+1);
219	}
220	res = gpgme_op_decrypt_result (c->gpg);
221	if (!res)
222	res_sig = gpgme_op_sign_result (c->gpg);
223	if (reg_prefs.cache_time > 0 && !c->is_card &&
224	(res \|\| res_sig)) {
225	if (agent_get_cache (c->keyid, &item))
226	agent_unlock_cache_entry (&item);
227	else
228	agent_put_cache (c->keyid, c->pwd, reg_prefs.cache_time);
229	}
230	c->cancel = 0;
231	EndDialog (dlg, TRUE);
232	return TRUE;
233
234	case IDCANCEL:
235	SetDlgItemText (dlg, item_ctrl_id (c->gpg_cmd), "");
236	c->cancel = 1;
237	EndDialog (dlg, FALSE);
238	return FALSE;
239	}
240	break;
241	}
242
243	return FALSE;
244	}
245
246
247	/* Extract the main keyid from @pass_info.
248	Return value: long main keyid or NULL for an error. */
249	static const char*
250	parse_gpg_keyid (const char *pass_info)
251	{
252	static char keyid[16+1];
253
254	/* XXX: check for leading alpha-chars? */
255	if (strlen (pass_info) < 16) {
256	log_debug ("parse_gpg_keyid: error '%s'\r\n", pass_info);
257	return NULL;
258	}
259	/* the format of the desc buffer looks like this:
260	request_keyid[16] main_keyid[16] keytype[1] keylength[4]
261	we use the main keyid to use only one cache entry. */
262	strncpy (keyid, pass_info+17, 16);
263	keyid[16] = 0;
264	return keyid;
265	}
266
267
268	/* Parse the information in @uid_hint and @pass_info to generate
269	a input message for the user in @desc. */
270	static int
271	parse_gpg_description (const char uid_hint, const char pass_info,
272	char *desc, int size)
273	{
274	gpgme_pubkey_algo_t algo;
275	char usedkey[16+1];
276	char mainkey[16+1];
277	char *p;
278	int n=0;
279
280	algo = (gpgme_pubkey_algo_t)0;
281	/* Each uid_hint contains a long key-ID so it is at least 16 bytes. */
282	if (strlen (uid_hint) < 17) {
283	*desc = 0;
284	log_debug ("parse_gpg_description: error '%s'\r\n", uid_hint);
285	return -1;
286	}
287
288	while (p = strsep ((char**)&pass_info, " ")) {
289	switch (n++) {
290	case 0: strncpy (mainkey, p, 16); mainkey[16] = 0; break;
291	case 1: strncpy (usedkey, p, 16); usedkey[16] = 0; break;
292	case 2: algo = (gpgme_pubkey_algo_t)atol (p); break;
293	}
294	}
295	uid_hint += 16; /* skip keyid */
296	uid_hint += 1; /* space */
297
298	if (strcmp (usedkey, mainkey))
299	_snprintf (desc, size-1,
300	_("You need a passphrase to unlock the secret key for\n"
301	"user: \"%s\"\n"
302	"%s key, ID %s (main key ID %s)\n"),
303	uid_hint, get_key_pubalgo (algo), usedkey+8, mainkey+8);
304	else if (!strcmp (usedkey, mainkey))
305	_snprintf (desc, size-1,
306	_("You need a passphrase to unlock the secret key for\n"
307	"user: \"%s\"\n"
308	"%s key, ID %s\n"),
309	uid_hint, get_key_pubalgo (algo), usedkey+8);
310	return 0;
311	}
312
313
314	/* Extract the serial number from the card ID @id and return it. */
315	const char*
316	extract_serial_no (const char *id)
317	{
318	static char buf[8];
319	char *p;
320
321	p = strchr (id, '/');
322	if (!p) {
323	log_debug ("extract_serial_no: error '%s'\r\n", id);
324	return NULL;
325	}
326	strncpy (buf, id+(p-id)-6, 6);
327	return buf;
328	}
329
330
331	/* Passphrase callback with the ability to support caching. */
332	gpgme_error_t
333	passphrase_cb (void hook, const char uid_hint,
334	const char *passphrase_info,
335	int prev_was_bad, int fd)
336	{
337	passphrase_cb_s c = (passphrase_cb_s)hook;
338	HANDLE hd = (HANDLE)fd;
339	void *item;
340	const char keyid=NULL, pass;
341	DWORD n;
342	int rc = 0;
343
344	if (!c) {
345	log_debug ("passphrase_cb: error '!c'\r\n");
346	return gpg_error (GPG_ERR_INV_ARG);
347	}
348	c->bad_pwd = prev_was_bad? 1 : 0;
349	if (prev_was_bad && !c->cancel) {
350	if (c->pwd)
351	burn_passphrase (&c->pwd);
352	agent_del_cache (c->keyid);
353	c->pwd_init = 1;
354	}
355
356	if (passphrase_info) {
357	if (strlen (passphrase_info) < 16 &&
358	!strstr (passphrase_info, "OPENPGP")) {
359	/* assume symetric encryption. */
360	int pos=2;
361	c->sym.sym_algo = atoi (passphrase_info);
362	if (c->sym.sym_algo > 9)
363	pos++;
364	/* XXX: be more strict. */
365	c->sym.s2k_mode = atoi (passphrase_info+pos);
366	c->sym.s2k_hash = atoi (passphrase_info+pos+2);
367	}
368
369	keyid = parse_gpg_keyid (passphrase_info);
370	pass = agent_get_cache (keyid+8, &item);
371	if (pass) {
372	agent_unlock_cache_entry (&item);
373	c->pwd_init = 0;
374	if (!WriteFile (hd, pass, strlen (pass), &n, NULL))
375	log_debug ("passphrase_cb: WriteFile() failed ec=%d\n", w32_errno);
376	if (!WriteFile (hd, "\n", 1, &n, NULL))
377	log_debug ("passphrase_cb: WriteFile() failed ec=%d\n", w32_errno);
378	return 0;
379	}
380	}
381
382	if (c->pwd_init) {
383	if (keyid && strlen (keyid) == 16)
384	strcpy (c->keyid, keyid+8);
385
386	/* if @passphrase_info contains 'OPENPGP' we assume a smart card
387	has been used. */
388	if (strstr (passphrase_info, "OPENPGP")) {
389	const char *s=passphrase_info;
390	while (s && s && s != 'D')
391	s++;
392	_snprintf (c->info, sizeof c->info-1,
393	_("Please enter the PIN to unlock your secret card key\n"
394	"Card: %s"), extract_serial_no (s));
395	c->is_card = 1;
396	}
397	else if (uid_hint)
398	parse_gpg_description (uid_hint, passphrase_info,
399	c->info, sizeof (c->info) - 1);
400	if (c->gpg_cmd == GPG_CMD_DECRYPT) {
401	rc = DialogBoxParam (glob_hinst, (LPCSTR)IDD_WINPT_DECRYPT,
402	(HWND)c->hwnd, passphrase_callback_proc,
403	(LPARAM)c);
404	}
405	else if (c->gpg_cmd == GPG_CMD_SIGN) {
406	rc = DialogBoxParam (glob_hinst, (LPCSTR)IDD_WINPT_DECRYPT_SIGN,
407	(HWND)c->hwnd, passphrase_callback_proc,
408	(LPARAM)c);
409	}
410	if (rc == -1) {
411	if (!WriteFile (hd, "\n", 1, &n, NULL))
412	log_debug ("passphrase_cb: WriteFile() failed ec=%d\n", w32_errno);
413	return 0;
414	}
415	c->pwd_init = 0;
416	}
417	if (c->cancel) {
418	if (!WriteFile (hd, "\n", 1, &n, NULL))
419	log_debug ("passphrase_cb: WriteFile() failed ec=%d\n", w32_errno);
420	return 0;
421	}
422
423	if (!WriteFile (hd, c->pwd, strlen (c->pwd), &n, NULL))
424	log_debug ("passphrase_cb: WriteFile() failed ec=%d\n", w32_errno);
425	if (!WriteFile (hd, "\n", 1, &n, NULL))
426	log_debug ("passphrase_cb: WriteFile() failed ec=%d\n", w32_errno);
427	return 0;
428	}
429
430
431	/* Initialize the given passphrase callback @cb with the
432	used gpgme context @ctx, the command @cmd and a title
433	@title for the dialog. */
434	void
435	set_gpg_passphrase_cb (passphrase_cb_s *cb, gpgme_ctx_t ctx,
436	int cmd, HWND hwnd, const char *title)
437	{
438	memset (cb, 0, sizeof *cb);
439	cb->gpg_cmd = cmd;
440	cb->bad_pwd = 0;
441	cb->is_card = 0;
442	cb->cancel = 0;
443	cb->hwnd = hwnd;
444	cb->pwd_init = 1;
445	free_if_alloc (cb->title);
446	cb->title = m_strdup (title);
447	if (!cb->title)
448	BUG (NULL);
449	gpgme_set_passphrase_cb (ctx, passphrase_cb, cb);
450	cb->gpg = ctx;
451	}
452
453
454	/* Release a passphrase callback @ctx. */
455	void
456	release_gpg_passphrase_cb (passphrase_cb_s *ctx)
457	{
458	gpgme_recipient_t r, n;
459
460	if (!ctx)
461	return;
462	sfree_if_alloc (ctx->pwd);
463	free_if_alloc (ctx->title);
464	r = ctx->recipients;
465	while (r) {
466	n = r->next;
467	safe_free (r->keyid);
468	safe_free (r);
469	r = n;
470	}
471	}
472
473
474	/* Simple check to measure passphrase (@pass) quality.
475	Return value: 0 on success. */
476	int
477	check_passwd_quality (const char *pass, int strict)
478	{
479	int i, nd=0, nc=0, n;
480
481	n = strlen (pass);
482	if (n < 8)
483	return -1;
484
485	for (i=0; i < n; i++) {
486	if (isdigit (pass[i]))
487	nd++;
488	if (isalpha (pass[i]))
489	nc++;
490	}
491
492	/* check that the passphrase contains letters and numbers. */
493	if (nd == n \|\| nc == n)
494	return -1;
495
496	return 0;
497	}