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      1 /*
      2  * wpa_supplicant - WPA/RSN IE and KDE processing
      3  * Copyright (c) 2003-2008, Jouni Malinen <j (at) 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 "common/ieee802_11_defs.h"
     21 #include "wpa_i.h"
     22 #include "wpa_ie.h"
     23 
     24 
     25 /**
     26  * wpa_parse_wpa_ie - Parse WPA/RSN IE
     27  * @wpa_ie: Pointer to WPA or RSN IE
     28  * @wpa_ie_len: Length of the WPA/RSN IE
     29  * @data: Pointer to data area for parsing results
     30  * Returns: 0 on success, -1 on failure
     31  *
     32  * Parse the contents of WPA or RSN IE and write the parsed data into data.
     33  */
     34 int wpa_parse_wpa_ie(const u8 *wpa_ie, size_t wpa_ie_len,
     35 		     struct wpa_ie_data *data)
     36 {
     37 	if (wpa_ie_len >= 1 && wpa_ie[0] == WLAN_EID_RSN)
     38 		return wpa_parse_wpa_ie_rsn(wpa_ie, wpa_ie_len, data);
     39 	else
     40 		return wpa_parse_wpa_ie_wpa(wpa_ie, wpa_ie_len, data);
     41 }
     42 
     43 
     44 static int wpa_gen_wpa_ie_wpa(u8 *wpa_ie, size_t wpa_ie_len,
     45 			      int pairwise_cipher, int group_cipher,
     46 			      int key_mgmt)
     47 {
     48 	u8 *pos;
     49 	struct wpa_ie_hdr *hdr;
     50 
     51 	if (wpa_ie_len < sizeof(*hdr) + WPA_SELECTOR_LEN +
     52 	    2 + WPA_SELECTOR_LEN + 2 + WPA_SELECTOR_LEN)
     53 		return -1;
     54 
     55 	hdr = (struct wpa_ie_hdr *) wpa_ie;
     56 	hdr->elem_id = WLAN_EID_VENDOR_SPECIFIC;
     57 	RSN_SELECTOR_PUT(hdr->oui, WPA_OUI_TYPE);
     58 	WPA_PUT_LE16(hdr->version, WPA_VERSION);
     59 	pos = (u8 *) (hdr + 1);
     60 
     61 	if (group_cipher == WPA_CIPHER_CCMP) {
     62 		RSN_SELECTOR_PUT(pos, WPA_CIPHER_SUITE_CCMP);
     63 	} else if (group_cipher == WPA_CIPHER_TKIP) {
     64 		RSN_SELECTOR_PUT(pos, WPA_CIPHER_SUITE_TKIP);
     65 	} else if (group_cipher == WPA_CIPHER_WEP104) {
     66 		RSN_SELECTOR_PUT(pos, WPA_CIPHER_SUITE_WEP104);
     67 	} else if (group_cipher == WPA_CIPHER_WEP40) {
     68 		RSN_SELECTOR_PUT(pos, WPA_CIPHER_SUITE_WEP40);
     69 	} else {
     70 		wpa_printf(MSG_WARNING, "Invalid group cipher (%d).",
     71 			   group_cipher);
     72 		return -1;
     73 	}
     74 	pos += WPA_SELECTOR_LEN;
     75 
     76 	*pos++ = 1;
     77 	*pos++ = 0;
     78 	if (pairwise_cipher == WPA_CIPHER_CCMP) {
     79 		RSN_SELECTOR_PUT(pos, WPA_CIPHER_SUITE_CCMP);
     80 	} else if (pairwise_cipher == WPA_CIPHER_TKIP) {
     81 		RSN_SELECTOR_PUT(pos, WPA_CIPHER_SUITE_TKIP);
     82 	} else if (pairwise_cipher == WPA_CIPHER_NONE) {
     83 		RSN_SELECTOR_PUT(pos, WPA_CIPHER_SUITE_NONE);
     84 	} else {
     85 		wpa_printf(MSG_WARNING, "Invalid pairwise cipher (%d).",
     86 			   pairwise_cipher);
     87 		return -1;
     88 	}
     89 	pos += WPA_SELECTOR_LEN;
     90 
     91 	*pos++ = 1;
     92 	*pos++ = 0;
     93 	if (key_mgmt == WPA_KEY_MGMT_IEEE8021X) {
     94 		RSN_SELECTOR_PUT(pos, WPA_AUTH_KEY_MGMT_UNSPEC_802_1X);
     95 	} else if (key_mgmt == WPA_KEY_MGMT_PSK) {
     96 		RSN_SELECTOR_PUT(pos, WPA_AUTH_KEY_MGMT_PSK_OVER_802_1X);
     97 	} else if (key_mgmt == WPA_KEY_MGMT_WPA_NONE) {
     98 		RSN_SELECTOR_PUT(pos, WPA_AUTH_KEY_MGMT_NONE);
     99 	} else {
    100 		wpa_printf(MSG_WARNING, "Invalid key management type (%d).",
    101 			   key_mgmt);
    102 		return -1;
    103 	}
    104 	pos += WPA_SELECTOR_LEN;
    105 
    106 	/* WPA Capabilities; use defaults, so no need to include it */
    107 
    108 	hdr->len = (pos - wpa_ie) - 2;
    109 
    110 	WPA_ASSERT((size_t) (pos - wpa_ie) <= wpa_ie_len);
    111 
    112 	return pos - wpa_ie;
    113 }
    114 
    115 
    116 static int wpa_gen_wpa_ie_rsn(u8 *rsn_ie, size_t rsn_ie_len,
    117 			      int pairwise_cipher, int group_cipher,
    118 			      int key_mgmt, int mgmt_group_cipher,
    119 			      struct wpa_sm *sm)
    120 {
    121 #ifndef CONFIG_NO_WPA2
    122 	u8 *pos;
    123 	struct rsn_ie_hdr *hdr;
    124 	u16 capab;
    125 
    126 	if (rsn_ie_len < sizeof(*hdr) + RSN_SELECTOR_LEN +
    127 	    2 + RSN_SELECTOR_LEN + 2 + RSN_SELECTOR_LEN + 2 +
    128 	    (sm->cur_pmksa ? 2 + PMKID_LEN : 0)) {
    129 		wpa_printf(MSG_DEBUG, "RSN: Too short IE buffer (%lu bytes)",
    130 			   (unsigned long) rsn_ie_len);
    131 		return -1;
    132 	}
    133 
    134 	hdr = (struct rsn_ie_hdr *) rsn_ie;
    135 	hdr->elem_id = WLAN_EID_RSN;
    136 	WPA_PUT_LE16(hdr->version, RSN_VERSION);
    137 	pos = (u8 *) (hdr + 1);
    138 
    139 	if (group_cipher == WPA_CIPHER_CCMP) {
    140 		RSN_SELECTOR_PUT(pos, RSN_CIPHER_SUITE_CCMP);
    141 	} else if (group_cipher == WPA_CIPHER_TKIP) {
    142 		RSN_SELECTOR_PUT(pos, RSN_CIPHER_SUITE_TKIP);
    143 	} else if (group_cipher == WPA_CIPHER_WEP104) {
    144 		RSN_SELECTOR_PUT(pos, RSN_CIPHER_SUITE_WEP104);
    145 	} else if (group_cipher == WPA_CIPHER_WEP40) {
    146 		RSN_SELECTOR_PUT(pos, RSN_CIPHER_SUITE_WEP40);
    147 	} else {
    148 		wpa_printf(MSG_WARNING, "Invalid group cipher (%d).",
    149 			   group_cipher);
    150 		return -1;
    151 	}
    152 	pos += RSN_SELECTOR_LEN;
    153 
    154 	*pos++ = 1;
    155 	*pos++ = 0;
    156 	if (pairwise_cipher == WPA_CIPHER_CCMP) {
    157 		RSN_SELECTOR_PUT(pos, RSN_CIPHER_SUITE_CCMP);
    158 	} else if (pairwise_cipher == WPA_CIPHER_TKIP) {
    159 		RSN_SELECTOR_PUT(pos, RSN_CIPHER_SUITE_TKIP);
    160 	} else if (pairwise_cipher == WPA_CIPHER_NONE) {
    161 		RSN_SELECTOR_PUT(pos, RSN_CIPHER_SUITE_NONE);
    162 	} else {
    163 		wpa_printf(MSG_WARNING, "Invalid pairwise cipher (%d).",
    164 			   pairwise_cipher);
    165 		return -1;
    166 	}
    167 	pos += RSN_SELECTOR_LEN;
    168 
    169 	*pos++ = 1;
    170 	*pos++ = 0;
    171 	if (key_mgmt == WPA_KEY_MGMT_IEEE8021X) {
    172 		RSN_SELECTOR_PUT(pos, RSN_AUTH_KEY_MGMT_UNSPEC_802_1X);
    173 	} else if (key_mgmt == WPA_KEY_MGMT_PSK) {
    174 		RSN_SELECTOR_PUT(pos, RSN_AUTH_KEY_MGMT_PSK_OVER_802_1X);
    175 #ifdef CONFIG_IEEE80211R
    176 	} else if (key_mgmt == WPA_KEY_MGMT_FT_IEEE8021X) {
    177 		RSN_SELECTOR_PUT(pos, RSN_AUTH_KEY_MGMT_FT_802_1X);
    178 	} else if (key_mgmt == WPA_KEY_MGMT_FT_PSK) {
    179 		RSN_SELECTOR_PUT(pos, RSN_AUTH_KEY_MGMT_FT_PSK);
    180 #endif /* CONFIG_IEEE80211R */
    181 #ifdef CONFIG_IEEE80211W
    182 	} else if (key_mgmt == WPA_KEY_MGMT_IEEE8021X_SHA256) {
    183 		RSN_SELECTOR_PUT(pos, RSN_AUTH_KEY_MGMT_802_1X_SHA256);
    184 	} else if (key_mgmt == WPA_KEY_MGMT_PSK_SHA256) {
    185 		RSN_SELECTOR_PUT(pos, RSN_AUTH_KEY_MGMT_PSK_SHA256);
    186 #endif /* CONFIG_IEEE80211W */
    187 	} else {
    188 		wpa_printf(MSG_WARNING, "Invalid key management type (%d).",
    189 			   key_mgmt);
    190 		return -1;
    191 	}
    192 	pos += RSN_SELECTOR_LEN;
    193 
    194 	/* RSN Capabilities */
    195 	capab = 0;
    196 #ifdef CONFIG_IEEE80211W
    197 	if (sm->mfp)
    198 		capab |= WPA_CAPABILITY_MFPC;
    199 	if (sm->mfp == 2)
    200 		capab |= WPA_CAPABILITY_MFPR;
    201 #endif /* CONFIG_IEEE80211W */
    202 	WPA_PUT_LE16(pos, capab);
    203 	pos += 2;
    204 
    205 	if (sm->cur_pmksa) {
    206 		/* PMKID Count (2 octets, little endian) */
    207 		*pos++ = 1;
    208 		*pos++ = 0;
    209 		/* PMKID */
    210 		os_memcpy(pos, sm->cur_pmksa->pmkid, PMKID_LEN);
    211 		pos += PMKID_LEN;
    212 	}
    213 
    214 #ifdef CONFIG_IEEE80211W
    215 	if (mgmt_group_cipher == WPA_CIPHER_AES_128_CMAC) {
    216 		if (!sm->cur_pmksa) {
    217 			/* PMKID Count */
    218 			WPA_PUT_LE16(pos, 0);
    219 			pos += 2;
    220 		}
    221 
    222 		/* Management Group Cipher Suite */
    223 		RSN_SELECTOR_PUT(pos, RSN_CIPHER_SUITE_AES_128_CMAC);
    224 		pos += RSN_SELECTOR_LEN;
    225 	}
    226 #endif /* CONFIG_IEEE80211W */
    227 
    228 	hdr->len = (pos - rsn_ie) - 2;
    229 
    230 	WPA_ASSERT((size_t) (pos - rsn_ie) <= rsn_ie_len);
    231 
    232 	return pos - rsn_ie;
    233 #else /* CONFIG_NO_WPA2 */
    234 	return -1;
    235 #endif /* CONFIG_NO_WPA2 */
    236 }
    237 
    238 
    239 /**
    240  * wpa_gen_wpa_ie - Generate WPA/RSN IE based on current security policy
    241  * @sm: Pointer to WPA state machine data from wpa_sm_init()
    242  * @wpa_ie: Pointer to memory area for the generated WPA/RSN IE
    243  * @wpa_ie_len: Maximum length of the generated WPA/RSN IE
    244  * Returns: Length of the generated WPA/RSN IE or -1 on failure
    245  */
    246 int wpa_gen_wpa_ie(struct wpa_sm *sm, u8 *wpa_ie, size_t wpa_ie_len)
    247 {
    248 	if (sm->proto == WPA_PROTO_RSN)
    249 		return wpa_gen_wpa_ie_rsn(wpa_ie, wpa_ie_len,
    250 					  sm->pairwise_cipher,
    251 					  sm->group_cipher,
    252 					  sm->key_mgmt, sm->mgmt_group_cipher,
    253 					  sm);
    254 	else
    255 		return wpa_gen_wpa_ie_wpa(wpa_ie, wpa_ie_len,
    256 					  sm->pairwise_cipher,
    257 					  sm->group_cipher,
    258 					  sm->key_mgmt);
    259 }
    260 
    261 
    262 /**
    263  * wpa_parse_generic - Parse EAPOL-Key Key Data Generic IEs
    264  * @pos: Pointer to the IE header
    265  * @end: Pointer to the end of the Key Data buffer
    266  * @ie: Pointer to parsed IE data
    267  * Returns: 0 on success, 1 if end mark is found, -1 on failure
    268  */
    269 static int wpa_parse_generic(const u8 *pos, const u8 *end,
    270 			     struct wpa_eapol_ie_parse *ie)
    271 {
    272 	if (pos[1] == 0)
    273 		return 1;
    274 
    275 	if (pos[1] >= 6 &&
    276 	    RSN_SELECTOR_GET(pos + 2) == WPA_OUI_TYPE &&
    277 	    pos[2 + WPA_SELECTOR_LEN] == 1 &&
    278 	    pos[2 + WPA_SELECTOR_LEN + 1] == 0) {
    279 		ie->wpa_ie = pos;
    280 		ie->wpa_ie_len = pos[1] + 2;
    281 		wpa_hexdump(MSG_DEBUG, "WPA: WPA IE in EAPOL-Key",
    282 			    ie->wpa_ie, ie->wpa_ie_len);
    283 		return 0;
    284 	}
    285 
    286 	if (pos + 1 + RSN_SELECTOR_LEN < end &&
    287 	    pos[1] >= RSN_SELECTOR_LEN + PMKID_LEN &&
    288 	    RSN_SELECTOR_GET(pos + 2) == RSN_KEY_DATA_PMKID) {
    289 		ie->pmkid = pos + 2 + RSN_SELECTOR_LEN;
    290 		wpa_hexdump(MSG_DEBUG, "WPA: PMKID in EAPOL-Key",
    291 			    pos, pos[1] + 2);
    292 		return 0;
    293 	}
    294 
    295 	if (pos[1] > RSN_SELECTOR_LEN + 2 &&
    296 	    RSN_SELECTOR_GET(pos + 2) == RSN_KEY_DATA_GROUPKEY) {
    297 		ie->gtk = pos + 2 + RSN_SELECTOR_LEN;
    298 		ie->gtk_len = pos[1] - RSN_SELECTOR_LEN;
    299 		wpa_hexdump_key(MSG_DEBUG, "WPA: GTK in EAPOL-Key",
    300 				pos, pos[1] + 2);
    301 		return 0;
    302 	}
    303 
    304 	if (pos[1] > RSN_SELECTOR_LEN + 2 &&
    305 	    RSN_SELECTOR_GET(pos + 2) == RSN_KEY_DATA_MAC_ADDR) {
    306 		ie->mac_addr = pos + 2 + RSN_SELECTOR_LEN;
    307 		ie->mac_addr_len = pos[1] - RSN_SELECTOR_LEN;
    308 		wpa_hexdump(MSG_DEBUG, "WPA: MAC Address in EAPOL-Key",
    309 			    pos, pos[1] + 2);
    310 		return 0;
    311 	}
    312 
    313 #ifdef CONFIG_PEERKEY
    314 	if (pos[1] > RSN_SELECTOR_LEN + 2 &&
    315 	    RSN_SELECTOR_GET(pos + 2) == RSN_KEY_DATA_SMK) {
    316 		ie->smk = pos + 2 + RSN_SELECTOR_LEN;
    317 		ie->smk_len = pos[1] - RSN_SELECTOR_LEN;
    318 		wpa_hexdump_key(MSG_DEBUG, "WPA: SMK in EAPOL-Key",
    319 				pos, pos[1] + 2);
    320 		return 0;
    321 	}
    322 
    323 	if (pos[1] > RSN_SELECTOR_LEN + 2 &&
    324 	    RSN_SELECTOR_GET(pos + 2) == RSN_KEY_DATA_NONCE) {
    325 		ie->nonce = pos + 2 + RSN_SELECTOR_LEN;
    326 		ie->nonce_len = pos[1] - RSN_SELECTOR_LEN;
    327 		wpa_hexdump(MSG_DEBUG, "WPA: Nonce in EAPOL-Key",
    328 			    pos, pos[1] + 2);
    329 		return 0;
    330 	}
    331 
    332 	if (pos[1] > RSN_SELECTOR_LEN + 2 &&
    333 	    RSN_SELECTOR_GET(pos + 2) == RSN_KEY_DATA_LIFETIME) {
    334 		ie->lifetime = pos + 2 + RSN_SELECTOR_LEN;
    335 		ie->lifetime_len = pos[1] - RSN_SELECTOR_LEN;
    336 		wpa_hexdump(MSG_DEBUG, "WPA: Lifetime in EAPOL-Key",
    337 			    pos, pos[1] + 2);
    338 		return 0;
    339 	}
    340 
    341 	if (pos[1] > RSN_SELECTOR_LEN + 2 &&
    342 	    RSN_SELECTOR_GET(pos + 2) == RSN_KEY_DATA_ERROR) {
    343 		ie->error = pos + 2 + RSN_SELECTOR_LEN;
    344 		ie->error_len = pos[1] - RSN_SELECTOR_LEN;
    345 		wpa_hexdump(MSG_DEBUG, "WPA: Error in EAPOL-Key",
    346 			    pos, pos[1] + 2);
    347 		return 0;
    348 	}
    349 #endif /* CONFIG_PEERKEY */
    350 
    351 #ifdef CONFIG_IEEE80211W
    352 	if (pos[1] > RSN_SELECTOR_LEN + 2 &&
    353 	    RSN_SELECTOR_GET(pos + 2) == RSN_KEY_DATA_IGTK) {
    354 		ie->igtk = pos + 2 + RSN_SELECTOR_LEN;
    355 		ie->igtk_len = pos[1] - RSN_SELECTOR_LEN;
    356 		wpa_hexdump_key(MSG_DEBUG, "WPA: IGTK in EAPOL-Key",
    357 				pos, pos[1] + 2);
    358 		return 0;
    359 	}
    360 #endif /* CONFIG_IEEE80211W */
    361 
    362 	return 0;
    363 }
    364 
    365 
    366 /**
    367  * wpa_supplicant_parse_ies - Parse EAPOL-Key Key Data IEs
    368  * @buf: Pointer to the Key Data buffer
    369  * @len: Key Data Length
    370  * @ie: Pointer to parsed IE data
    371  * Returns: 0 on success, -1 on failure
    372  */
    373 int wpa_supplicant_parse_ies(const u8 *buf, size_t len,
    374 			     struct wpa_eapol_ie_parse *ie)
    375 {
    376 	const u8 *pos, *end;
    377 	int ret = 0;
    378 
    379 	os_memset(ie, 0, sizeof(*ie));
    380 	for (pos = buf, end = pos + len; pos + 1 < end; pos += 2 + pos[1]) {
    381 		if (pos[0] == 0xdd &&
    382 		    ((pos == buf + len - 1) || pos[1] == 0)) {
    383 			/* Ignore padding */
    384 			break;
    385 		}
    386 		if (pos + 2 + pos[1] > end) {
    387 			wpa_printf(MSG_DEBUG, "WPA: EAPOL-Key Key Data "
    388 				   "underflow (ie=%d len=%d pos=%d)",
    389 				   pos[0], pos[1], (int) (pos - buf));
    390 			wpa_hexdump_key(MSG_DEBUG, "WPA: Key Data",
    391 					buf, len);
    392 			ret = -1;
    393 			break;
    394 		}
    395 		if (*pos == WLAN_EID_RSN) {
    396 			ie->rsn_ie = pos;
    397 			ie->rsn_ie_len = pos[1] + 2;
    398 			wpa_hexdump(MSG_DEBUG, "WPA: RSN IE in EAPOL-Key",
    399 				    ie->rsn_ie, ie->rsn_ie_len);
    400 		} else if (*pos == WLAN_EID_MOBILITY_DOMAIN) {
    401 			ie->mdie = pos;
    402 			ie->mdie_len = pos[1] + 2;
    403 			wpa_hexdump(MSG_DEBUG, "WPA: MDIE in EAPOL-Key",
    404 				    ie->mdie, ie->mdie_len);
    405 		} else if (*pos == WLAN_EID_FAST_BSS_TRANSITION) {
    406 			ie->ftie = pos;
    407 			ie->ftie_len = pos[1] + 2;
    408 			wpa_hexdump(MSG_DEBUG, "WPA: FTIE in EAPOL-Key",
    409 				    ie->ftie, ie->ftie_len);
    410 		} else if (*pos == WLAN_EID_TIMEOUT_INTERVAL && pos[1] >= 5) {
    411 			if (pos[2] == WLAN_TIMEOUT_REASSOC_DEADLINE) {
    412 				ie->reassoc_deadline = pos;
    413 				wpa_hexdump(MSG_DEBUG, "WPA: Reassoc Deadline "
    414 					    "in EAPOL-Key",
    415 					    ie->reassoc_deadline, pos[1] + 2);
    416 			} else if (pos[2] == WLAN_TIMEOUT_KEY_LIFETIME) {
    417 				ie->key_lifetime = pos;
    418 				wpa_hexdump(MSG_DEBUG, "WPA: KeyLifetime "
    419 					    "in EAPOL-Key",
    420 					    ie->key_lifetime, pos[1] + 2);
    421 			} else {
    422 				wpa_hexdump(MSG_DEBUG, "WPA: Unrecognized "
    423 					    "EAPOL-Key Key Data IE",
    424 					    pos, 2 + pos[1]);
    425 			}
    426 		} else if (*pos == WLAN_EID_LINK_ID) {
    427 			ie->lnkid = pos;
    428 			ie->lnkid_len = pos[1] + 2;
    429 		} else if (*pos == WLAN_EID_EXT_CAPAB) {
    430 			ie->ext_capab = pos;
    431 			ie->ext_capab_len = pos[1] + 2;
    432 		} else if (*pos == WLAN_EID_VENDOR_SPECIFIC) {
    433 			ret = wpa_parse_generic(pos, end, ie);
    434 			if (ret < 0)
    435 				break;
    436 			if (ret > 0) {
    437 				ret = 0;
    438 				break;
    439 			}
    440 		} else {
    441 			wpa_hexdump(MSG_DEBUG, "WPA: Unrecognized EAPOL-Key "
    442 				    "Key Data IE", pos, 2 + pos[1]);
    443 		}
    444 	}
    445 
    446 	return ret;
    447 }
    448