hostapd: Update vendor branch to 0.6.10
[dragonfly.git] / contrib / hostapd / src / rsn_supp / wpa_ie.c
1 /*
2  * wpa_supplicant - WPA/RSN IE and KDE processing
3  * Copyright (c) 2003-2008, Jouni Malinen <j@w1.fi>
4  *
5  * This program is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License version 2 as
7  * published by the Free Software Foundation.
8  *
9  * Alternatively, this software may be distributed under the terms of BSD
10  * license.
11  *
12  * See README and COPYING for more details.
13  */
14
15 #include "includes.h"
16
17 #include "common.h"
18 #include "wpa.h"
19 #include "pmksa_cache.h"
20 #include "ieee802_11_defs.h"
21 #include "wpa_i.h"
22 #include "wpa_ie.h"
23
24
25 static int wpa_selector_to_bitfield(const u8 *s)
26 {
27         if (RSN_SELECTOR_GET(s) == WPA_CIPHER_SUITE_NONE)
28                 return WPA_CIPHER_NONE;
29         if (RSN_SELECTOR_GET(s) == WPA_CIPHER_SUITE_WEP40)
30                 return WPA_CIPHER_WEP40;
31         if (RSN_SELECTOR_GET(s) == WPA_CIPHER_SUITE_TKIP)
32                 return WPA_CIPHER_TKIP;
33         if (RSN_SELECTOR_GET(s) == WPA_CIPHER_SUITE_CCMP)
34                 return WPA_CIPHER_CCMP;
35         if (RSN_SELECTOR_GET(s) == WPA_CIPHER_SUITE_WEP104)
36                 return WPA_CIPHER_WEP104;
37         return 0;
38 }
39
40
41 static int wpa_key_mgmt_to_bitfield(const u8 *s)
42 {
43         if (RSN_SELECTOR_GET(s) == WPA_AUTH_KEY_MGMT_UNSPEC_802_1X)
44                 return WPA_KEY_MGMT_IEEE8021X;
45         if (RSN_SELECTOR_GET(s) == WPA_AUTH_KEY_MGMT_PSK_OVER_802_1X)
46                 return WPA_KEY_MGMT_PSK;
47         if (RSN_SELECTOR_GET(s) == WPA_AUTH_KEY_MGMT_NONE)
48                 return WPA_KEY_MGMT_WPA_NONE;
49         return 0;
50 }
51
52
53 static int wpa_parse_wpa_ie_wpa(const u8 *wpa_ie, size_t wpa_ie_len,
54                                 struct wpa_ie_data *data)
55 {
56         const struct wpa_ie_hdr *hdr;
57         const u8 *pos;
58         int left;
59         int i, count;
60
61         os_memset(data, 0, sizeof(*data));
62         data->proto = WPA_PROTO_WPA;
63         data->pairwise_cipher = WPA_CIPHER_TKIP;
64         data->group_cipher = WPA_CIPHER_TKIP;
65         data->key_mgmt = WPA_KEY_MGMT_IEEE8021X;
66         data->capabilities = 0;
67         data->pmkid = NULL;
68         data->num_pmkid = 0;
69         data->mgmt_group_cipher = 0;
70
71         if (wpa_ie_len == 0) {
72                 /* No WPA IE - fail silently */
73                 return -1;
74         }
75
76         if (wpa_ie_len < sizeof(struct wpa_ie_hdr)) {
77                 wpa_printf(MSG_DEBUG, "%s: ie len too short %lu",
78                            __func__, (unsigned long) wpa_ie_len);
79                 return -1;
80         }
81
82         hdr = (const struct wpa_ie_hdr *) wpa_ie;
83
84         if (hdr->elem_id != WLAN_EID_VENDOR_SPECIFIC ||
85             hdr->len != wpa_ie_len - 2 ||
86             RSN_SELECTOR_GET(hdr->oui) != WPA_OUI_TYPE ||
87             WPA_GET_LE16(hdr->version) != WPA_VERSION) {
88                 wpa_printf(MSG_DEBUG, "%s: malformed ie or unknown version",
89                            __func__);
90                 return -1;
91         }
92
93         pos = (const u8 *) (hdr + 1);
94         left = wpa_ie_len - sizeof(*hdr);
95
96         if (left >= WPA_SELECTOR_LEN) {
97                 data->group_cipher = wpa_selector_to_bitfield(pos);
98                 pos += WPA_SELECTOR_LEN;
99                 left -= WPA_SELECTOR_LEN;
100         } else if (left > 0) {
101                 wpa_printf(MSG_DEBUG, "%s: ie length mismatch, %u too much",
102                            __func__, left);
103                 return -1;
104         }
105
106         if (left >= 2) {
107                 data->pairwise_cipher = 0;
108                 count = WPA_GET_LE16(pos);
109                 pos += 2;
110                 left -= 2;
111                 if (count == 0 || left < count * WPA_SELECTOR_LEN) {
112                         wpa_printf(MSG_DEBUG, "%s: ie count botch (pairwise), "
113                                    "count %u left %u", __func__, count, left);
114                         return -1;
115                 }
116                 for (i = 0; i < count; i++) {
117                         data->pairwise_cipher |= wpa_selector_to_bitfield(pos);
118                         pos += WPA_SELECTOR_LEN;
119                         left -= WPA_SELECTOR_LEN;
120                 }
121         } else if (left == 1) {
122                 wpa_printf(MSG_DEBUG, "%s: ie too short (for key mgmt)",
123                            __func__);
124                 return -1;
125         }
126
127         if (left >= 2) {
128                 data->key_mgmt = 0;
129                 count = WPA_GET_LE16(pos);
130                 pos += 2;
131                 left -= 2;
132                 if (count == 0 || left < count * WPA_SELECTOR_LEN) {
133                         wpa_printf(MSG_DEBUG, "%s: ie count botch (key mgmt), "
134                                    "count %u left %u", __func__, count, left);
135                         return -1;
136                 }
137                 for (i = 0; i < count; i++) {
138                         data->key_mgmt |= wpa_key_mgmt_to_bitfield(pos);
139                         pos += WPA_SELECTOR_LEN;
140                         left -= WPA_SELECTOR_LEN;
141                 }
142         } else if (left == 1) {
143                 wpa_printf(MSG_DEBUG, "%s: ie too short (for capabilities)",
144                            __func__);
145                 return -1;
146         }
147
148         if (left >= 2) {
149                 data->capabilities = WPA_GET_LE16(pos);
150                 pos += 2;
151                 left -= 2;
152         }
153
154         if (left > 0) {
155                 wpa_printf(MSG_DEBUG, "%s: ie has %u trailing bytes - ignored",
156                            __func__, left);
157         }
158
159         return 0;
160 }
161
162
163 /**
164  * wpa_parse_wpa_ie - Parse WPA/RSN IE
165  * @wpa_ie: Pointer to WPA or RSN IE
166  * @wpa_ie_len: Length of the WPA/RSN IE
167  * @data: Pointer to data area for parsing results
168  * Returns: 0 on success, -1 on failure
169  *
170  * Parse the contents of WPA or RSN IE and write the parsed data into data.
171  */
172 int wpa_parse_wpa_ie(const u8 *wpa_ie, size_t wpa_ie_len,
173                      struct wpa_ie_data *data)
174 {
175         if (wpa_ie_len >= 1 && wpa_ie[0] == WLAN_EID_RSN)
176                 return wpa_parse_wpa_ie_rsn(wpa_ie, wpa_ie_len, data);
177         else
178                 return wpa_parse_wpa_ie_wpa(wpa_ie, wpa_ie_len, data);
179 }
180
181
182 static int wpa_gen_wpa_ie_wpa(u8 *wpa_ie, size_t wpa_ie_len,
183                               int pairwise_cipher, int group_cipher,
184                               int key_mgmt)
185 {
186         u8 *pos;
187         struct wpa_ie_hdr *hdr;
188
189         if (wpa_ie_len < sizeof(*hdr) + WPA_SELECTOR_LEN +
190             2 + WPA_SELECTOR_LEN + 2 + WPA_SELECTOR_LEN)
191                 return -1;
192
193         hdr = (struct wpa_ie_hdr *) wpa_ie;
194         hdr->elem_id = WLAN_EID_VENDOR_SPECIFIC;
195         RSN_SELECTOR_PUT(hdr->oui, WPA_OUI_TYPE);
196         WPA_PUT_LE16(hdr->version, WPA_VERSION);
197         pos = (u8 *) (hdr + 1);
198
199         if (group_cipher == WPA_CIPHER_CCMP) {
200                 RSN_SELECTOR_PUT(pos, WPA_CIPHER_SUITE_CCMP);
201         } else if (group_cipher == WPA_CIPHER_TKIP) {
202                 RSN_SELECTOR_PUT(pos, WPA_CIPHER_SUITE_TKIP);
203         } else if (group_cipher == WPA_CIPHER_WEP104) {
204                 RSN_SELECTOR_PUT(pos, WPA_CIPHER_SUITE_WEP104);
205         } else if (group_cipher == WPA_CIPHER_WEP40) {
206                 RSN_SELECTOR_PUT(pos, WPA_CIPHER_SUITE_WEP40);
207         } else {
208                 wpa_printf(MSG_WARNING, "Invalid group cipher (%d).",
209                            group_cipher);
210                 return -1;
211         }
212         pos += WPA_SELECTOR_LEN;
213
214         *pos++ = 1;
215         *pos++ = 0;
216         if (pairwise_cipher == WPA_CIPHER_CCMP) {
217                 RSN_SELECTOR_PUT(pos, WPA_CIPHER_SUITE_CCMP);
218         } else if (pairwise_cipher == WPA_CIPHER_TKIP) {
219                 RSN_SELECTOR_PUT(pos, WPA_CIPHER_SUITE_TKIP);
220         } else if (pairwise_cipher == WPA_CIPHER_NONE) {
221                 RSN_SELECTOR_PUT(pos, WPA_CIPHER_SUITE_NONE);
222         } else {
223                 wpa_printf(MSG_WARNING, "Invalid pairwise cipher (%d).",
224                            pairwise_cipher);
225                 return -1;
226         }
227         pos += WPA_SELECTOR_LEN;
228
229         *pos++ = 1;
230         *pos++ = 0;
231         if (key_mgmt == WPA_KEY_MGMT_IEEE8021X) {
232                 RSN_SELECTOR_PUT(pos, WPA_AUTH_KEY_MGMT_UNSPEC_802_1X);
233         } else if (key_mgmt == WPA_KEY_MGMT_PSK) {
234                 RSN_SELECTOR_PUT(pos, WPA_AUTH_KEY_MGMT_PSK_OVER_802_1X);
235         } else if (key_mgmt == WPA_KEY_MGMT_WPA_NONE) {
236                 RSN_SELECTOR_PUT(pos, WPA_AUTH_KEY_MGMT_NONE);
237         } else {
238                 wpa_printf(MSG_WARNING, "Invalid key management type (%d).",
239                            key_mgmt);
240                 return -1;
241         }
242         pos += WPA_SELECTOR_LEN;
243
244         /* WPA Capabilities; use defaults, so no need to include it */
245
246         hdr->len = (pos - wpa_ie) - 2;
247
248         WPA_ASSERT((size_t) (pos - wpa_ie) <= wpa_ie_len);
249
250         return pos - wpa_ie;
251 }
252
253
254 static int wpa_gen_wpa_ie_rsn(u8 *rsn_ie, size_t rsn_ie_len,
255                               int pairwise_cipher, int group_cipher,
256                               int key_mgmt, int mgmt_group_cipher,
257                               struct wpa_sm *sm)
258 {
259 #ifndef CONFIG_NO_WPA2
260         u8 *pos;
261         struct rsn_ie_hdr *hdr;
262         u16 capab;
263
264         if (rsn_ie_len < sizeof(*hdr) + RSN_SELECTOR_LEN +
265             2 + RSN_SELECTOR_LEN + 2 + RSN_SELECTOR_LEN + 2 +
266             (sm->cur_pmksa ? 2 + PMKID_LEN : 0)) {
267                 wpa_printf(MSG_DEBUG, "RSN: Too short IE buffer (%lu bytes)",
268                            (unsigned long) rsn_ie_len);
269                 return -1;
270         }
271
272         hdr = (struct rsn_ie_hdr *) rsn_ie;
273         hdr->elem_id = WLAN_EID_RSN;
274         WPA_PUT_LE16(hdr->version, RSN_VERSION);
275         pos = (u8 *) (hdr + 1);
276
277         if (group_cipher == WPA_CIPHER_CCMP) {
278                 RSN_SELECTOR_PUT(pos, RSN_CIPHER_SUITE_CCMP);
279         } else if (group_cipher == WPA_CIPHER_TKIP) {
280                 RSN_SELECTOR_PUT(pos, RSN_CIPHER_SUITE_TKIP);
281         } else if (group_cipher == WPA_CIPHER_WEP104) {
282                 RSN_SELECTOR_PUT(pos, RSN_CIPHER_SUITE_WEP104);
283         } else if (group_cipher == WPA_CIPHER_WEP40) {
284                 RSN_SELECTOR_PUT(pos, RSN_CIPHER_SUITE_WEP40);
285         } else {
286                 wpa_printf(MSG_WARNING, "Invalid group cipher (%d).",
287                            group_cipher);
288                 return -1;
289         }
290         pos += RSN_SELECTOR_LEN;
291
292         *pos++ = 1;
293         *pos++ = 0;
294         if (pairwise_cipher == WPA_CIPHER_CCMP) {
295                 RSN_SELECTOR_PUT(pos, RSN_CIPHER_SUITE_CCMP);
296         } else if (pairwise_cipher == WPA_CIPHER_TKIP) {
297                 RSN_SELECTOR_PUT(pos, RSN_CIPHER_SUITE_TKIP);
298         } else if (pairwise_cipher == WPA_CIPHER_NONE) {
299                 RSN_SELECTOR_PUT(pos, RSN_CIPHER_SUITE_NONE);
300         } else {
301                 wpa_printf(MSG_WARNING, "Invalid pairwise cipher (%d).",
302                            pairwise_cipher);
303                 return -1;
304         }
305         pos += RSN_SELECTOR_LEN;
306
307         *pos++ = 1;
308         *pos++ = 0;
309         if (key_mgmt == WPA_KEY_MGMT_IEEE8021X) {
310                 RSN_SELECTOR_PUT(pos, RSN_AUTH_KEY_MGMT_UNSPEC_802_1X);
311         } else if (key_mgmt == WPA_KEY_MGMT_PSK) {
312                 RSN_SELECTOR_PUT(pos, RSN_AUTH_KEY_MGMT_PSK_OVER_802_1X);
313 #ifdef CONFIG_IEEE80211R
314         } else if (key_mgmt == WPA_KEY_MGMT_FT_IEEE8021X) {
315                 RSN_SELECTOR_PUT(pos, RSN_AUTH_KEY_MGMT_FT_802_1X);
316         } else if (key_mgmt == WPA_KEY_MGMT_FT_PSK) {
317                 RSN_SELECTOR_PUT(pos, RSN_AUTH_KEY_MGMT_FT_PSK);
318 #endif /* CONFIG_IEEE80211R */
319 #ifdef CONFIG_IEEE80211W
320         } else if (key_mgmt == WPA_KEY_MGMT_IEEE8021X_SHA256) {
321                 RSN_SELECTOR_PUT(pos, RSN_AUTH_KEY_MGMT_802_1X_SHA256);
322         } else if (key_mgmt == WPA_KEY_MGMT_PSK_SHA256) {
323                 RSN_SELECTOR_PUT(pos, RSN_AUTH_KEY_MGMT_PSK_SHA256);
324 #endif /* CONFIG_IEEE80211W */
325         } else {
326                 wpa_printf(MSG_WARNING, "Invalid key management type (%d).",
327                            key_mgmt);
328                 return -1;
329         }
330         pos += RSN_SELECTOR_LEN;
331
332         /* RSN Capabilities */
333         capab = 0;
334 #ifdef CONFIG_IEEE80211W
335         if (mgmt_group_cipher == WPA_CIPHER_AES_128_CMAC)
336                 capab |= WPA_CAPABILITY_MFPC;
337 #endif /* CONFIG_IEEE80211W */
338         WPA_PUT_LE16(pos, capab);
339         pos += 2;
340
341         if (sm->cur_pmksa) {
342                 /* PMKID Count (2 octets, little endian) */
343                 *pos++ = 1;
344                 *pos++ = 0;
345                 /* PMKID */
346                 os_memcpy(pos, sm->cur_pmksa->pmkid, PMKID_LEN);
347                 pos += PMKID_LEN;
348         }
349
350 #ifdef CONFIG_IEEE80211W
351         if (mgmt_group_cipher == WPA_CIPHER_AES_128_CMAC) {
352                 if (!sm->cur_pmksa) {
353                         /* PMKID Count */
354                         WPA_PUT_LE16(pos, 0);
355                         pos += 2;
356                 }
357
358                 /* Management Group Cipher Suite */
359                 RSN_SELECTOR_PUT(pos, RSN_CIPHER_SUITE_AES_128_CMAC);
360                 pos += RSN_SELECTOR_LEN;
361         }
362 #endif /* CONFIG_IEEE80211W */
363
364         hdr->len = (pos - rsn_ie) - 2;
365
366         WPA_ASSERT((size_t) (pos - rsn_ie) <= rsn_ie_len);
367
368         return pos - rsn_ie;
369 #else /* CONFIG_NO_WPA2 */
370         return -1;
371 #endif /* CONFIG_NO_WPA2 */
372 }
373
374
375 /**
376  * wpa_gen_wpa_ie - Generate WPA/RSN IE based on current security policy
377  * @sm: Pointer to WPA state machine data from wpa_sm_init()
378  * @wpa_ie: Pointer to memory area for the generated WPA/RSN IE
379  * @wpa_ie_len: Maximum length of the generated WPA/RSN IE
380  * Returns: Length of the generated WPA/RSN IE or -1 on failure
381  */
382 int wpa_gen_wpa_ie(struct wpa_sm *sm, u8 *wpa_ie, size_t wpa_ie_len)
383 {
384         if (sm->proto == WPA_PROTO_RSN)
385                 return wpa_gen_wpa_ie_rsn(wpa_ie, wpa_ie_len,
386                                           sm->pairwise_cipher,
387                                           sm->group_cipher,
388                                           sm->key_mgmt, sm->mgmt_group_cipher,
389                                           sm);
390         else
391                 return wpa_gen_wpa_ie_wpa(wpa_ie, wpa_ie_len,
392                                           sm->pairwise_cipher,
393                                           sm->group_cipher,
394                                           sm->key_mgmt);
395 }
396
397
398 /**
399  * wpa_parse_generic - Parse EAPOL-Key Key Data Generic IEs
400  * @pos: Pointer to the IE header
401  * @end: Pointer to the end of the Key Data buffer
402  * @ie: Pointer to parsed IE data
403  * Returns: 0 on success, 1 if end mark is found, -1 on failure
404  */
405 static int wpa_parse_generic(const u8 *pos, const u8 *end,
406                              struct wpa_eapol_ie_parse *ie)
407 {
408         if (pos[1] == 0)
409                 return 1;
410
411         if (pos[1] >= 6 &&
412             RSN_SELECTOR_GET(pos + 2) == WPA_OUI_TYPE &&
413             pos[2 + WPA_SELECTOR_LEN] == 1 &&
414             pos[2 + WPA_SELECTOR_LEN + 1] == 0) {
415                 ie->wpa_ie = pos;
416                 ie->wpa_ie_len = pos[1] + 2;
417                 return 0;
418         }
419
420         if (pos + 1 + RSN_SELECTOR_LEN < end &&
421             pos[1] >= RSN_SELECTOR_LEN + PMKID_LEN &&
422             RSN_SELECTOR_GET(pos + 2) == RSN_KEY_DATA_PMKID) {
423                 ie->pmkid = pos + 2 + RSN_SELECTOR_LEN;
424                 return 0;
425         }
426
427         if (pos[1] > RSN_SELECTOR_LEN + 2 &&
428             RSN_SELECTOR_GET(pos + 2) == RSN_KEY_DATA_GROUPKEY) {
429                 ie->gtk = pos + 2 + RSN_SELECTOR_LEN;
430                 ie->gtk_len = pos[1] - RSN_SELECTOR_LEN;
431                 return 0;
432         }
433
434         if (pos[1] > RSN_SELECTOR_LEN + 2 &&
435             RSN_SELECTOR_GET(pos + 2) == RSN_KEY_DATA_MAC_ADDR) {
436                 ie->mac_addr = pos + 2 + RSN_SELECTOR_LEN;
437                 ie->mac_addr_len = pos[1] - RSN_SELECTOR_LEN;
438                 return 0;
439         }
440
441 #ifdef CONFIG_PEERKEY
442         if (pos[1] > RSN_SELECTOR_LEN + 2 &&
443             RSN_SELECTOR_GET(pos + 2) == RSN_KEY_DATA_SMK) {
444                 ie->smk = pos + 2 + RSN_SELECTOR_LEN;
445                 ie->smk_len = pos[1] - RSN_SELECTOR_LEN;
446                 return 0;
447         }
448
449         if (pos[1] > RSN_SELECTOR_LEN + 2 &&
450             RSN_SELECTOR_GET(pos + 2) == RSN_KEY_DATA_NONCE) {
451                 ie->nonce = pos + 2 + RSN_SELECTOR_LEN;
452                 ie->nonce_len = pos[1] - RSN_SELECTOR_LEN;
453                 return 0;
454         }
455
456         if (pos[1] > RSN_SELECTOR_LEN + 2 &&
457             RSN_SELECTOR_GET(pos + 2) == RSN_KEY_DATA_LIFETIME) {
458                 ie->lifetime = pos + 2 + RSN_SELECTOR_LEN;
459                 ie->lifetime_len = pos[1] - RSN_SELECTOR_LEN;
460                 return 0;
461         }
462
463         if (pos[1] > RSN_SELECTOR_LEN + 2 &&
464             RSN_SELECTOR_GET(pos + 2) == RSN_KEY_DATA_ERROR) {
465                 ie->error = pos + 2 + RSN_SELECTOR_LEN;
466                 ie->error_len = pos[1] - RSN_SELECTOR_LEN;
467                 return 0;
468         }
469 #endif /* CONFIG_PEERKEY */
470
471 #ifdef CONFIG_IEEE80211W
472         if (pos[1] > RSN_SELECTOR_LEN + 2 &&
473             RSN_SELECTOR_GET(pos + 2) == RSN_KEY_DATA_IGTK) {
474                 ie->igtk = pos + 2 + RSN_SELECTOR_LEN;
475                 ie->igtk_len = pos[1] - RSN_SELECTOR_LEN;
476                 return 0;
477         }
478 #endif /* CONFIG_IEEE80211W */
479
480         return 0;
481 }
482
483
484 /**
485  * wpa_supplicant_parse_ies - Parse EAPOL-Key Key Data IEs
486  * @buf: Pointer to the Key Data buffer
487  * @len: Key Data Length
488  * @ie: Pointer to parsed IE data
489  * Returns: 0 on success, -1 on failure
490  */
491 int wpa_supplicant_parse_ies(const u8 *buf, size_t len,
492                              struct wpa_eapol_ie_parse *ie)
493 {
494         const u8 *pos, *end;
495         int ret = 0;
496
497         os_memset(ie, 0, sizeof(*ie));
498         for (pos = buf, end = pos + len; pos + 1 < end; pos += 2 + pos[1]) {
499                 if (pos[0] == 0xdd &&
500                     ((pos == buf + len - 1) || pos[1] == 0)) {
501                         /* Ignore padding */
502                         break;
503                 }
504                 if (pos + 2 + pos[1] > end) {
505                         wpa_printf(MSG_DEBUG, "WPA: EAPOL-Key Key Data "
506                                    "underflow (ie=%d len=%d pos=%d)",
507                                    pos[0], pos[1], (int) (pos - buf));
508                         wpa_hexdump_key(MSG_DEBUG, "WPA: Key Data",
509                                         buf, len);
510                         ret = -1;
511                         break;
512                 }
513                 if (*pos == WLAN_EID_RSN) {
514                         ie->rsn_ie = pos;
515                         ie->rsn_ie_len = pos[1] + 2;
516 #ifdef CONFIG_IEEE80211R
517                 } else if (*pos == WLAN_EID_MOBILITY_DOMAIN) {
518                         ie->mdie = pos;
519                         ie->mdie_len = pos[1] + 2;
520 #endif /* CONFIG_IEEE80211R */
521                 } else if (*pos == WLAN_EID_VENDOR_SPECIFIC) {
522                         ret = wpa_parse_generic(pos, end, ie);
523                         if (ret < 0)
524                                 break;
525                         if (ret > 0) {
526                                 ret = 0;
527                                 break;
528                         }
529                 } else {
530                         wpa_hexdump(MSG_DEBUG, "WPA: Unrecognized EAPOL-Key "
531                                     "Key Data IE", pos, 2 + pos[1]);
532                 }
533         }
534
535         return ret;
536 }