4 * Copyright (c) 2006 CACE Technologies, Davis (California)
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the project nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
19 * Alternatively, this software may be distributed under the terms of the
20 * GNU General Public License ("GPL") version 2 as published by the Free
21 * Software Foundation.
23 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 /****************************************************************************/
43 #include <epan/tvbuff.h>
44 #include <epan/crc32.h>
45 #include <epan/strutil.h>
46 #include <epan/emem.h>
47 #include <epan/pint.h>
48 #include <epan/crypt/crypt-rc4.h>
49 #include <epan/crypt/airpdcap_rijndael.h>
51 #include "airpdcap_system.h"
52 #include "airpdcap_int.h"
54 #include "crypt-sha1.h"
55 #include "crypt-md5.h"
57 #include "airpdcap_debug.h"
59 #include "wep-wpadefs.h"
62 /****************************************************************************/
64 /****************************************************************************/
65 /* Constant definitions */
67 #define AIRPDCAP_SHA_DIGEST_LEN 20
69 /* EAPOL definitions */
71 * Length of the EAPOL-Key key confirmation key (KCK) used to calculate
72 * MIC over EAPOL frame and validate an EAPOL packet (128 bits)
74 #define AIRPDCAP_WPA_KCK_LEN 16
76 *Offset of the Key MIC in the EAPOL packet body
78 #define AIRPDCAP_WPA_MICKEY_OFFSET 77
80 * Maximum length of the EAPOL packet (it depends on the maximum MAC
83 #define AIRPDCAP_WPA_MAX_EAPOL_LEN 4095
85 * EAPOL Key Descriptor Version 1, used for all EAPOL-Key frames to and
86 * from a STA when neither the group nor pairwise ciphers are CCMP for
89 * Defined in 802.11i-2004, page 78
91 #define AIRPDCAP_WPA_KEY_VER_NOT_CCMP 1
93 * EAPOL Key Descriptor Version 2, used for all EAPOL-Key frames to and
94 * from a STA when either the pairwise or the group cipher is AES-CCMP
95 * for Key Descriptor 2.
97 * Defined in 802.11i-2004, page 78
99 #define AIRPDCAP_WPA_KEY_VER_AES_CCMP 2
101 /** Define EAPOL Key Descriptor type values: use 254 for WPA and 2 for WPA2 **/
102 #define AIRPDCAP_RSN_WPA_KEY_DESCRIPTOR 254
103 #define AIRPDCAP_RSN_WPA2_KEY_DESCRIPTOR 2
105 /****************************************************************************/
109 /****************************************************************************/
110 /* Macro definitions */
112 extern const UINT32 crc32_table[256];
113 #define CRC(crc, ch) (crc = (crc >> 8) ^ crc32_table[(crc ^ (ch)) & 0xff])
115 #define AIRPDCAP_GET_TK(ptk) (ptk + 32)
117 /****************************************************************************/
119 /****************************************************************************/
120 /* Type definitions */
122 /* Internal function prototype declarations */
129 * It is a step of the PBKDF2 (specifically the PKCS #5 v2.0) defined in
130 * the RFC 2898 to derive a key (used as PMK in WPA)
131 * @param password [IN] pointer to a password (sequence of between 8 and
132 * 63 ASCII encoded characters)
133 * @param ssid [IN] pointer to the SSID string encoded in max 32 ASCII
135 * @param iterations [IN] times to hash the password (4096 for WPA)
136 * @param count [IN] ???
137 * @param output [OUT] pointer to a preallocated buffer of
138 * AIRPDCAP_SHA_DIGEST_LEN characters that will contain a part of the key
140 static INT AirPDcapRsnaPwd2PskStep(
141 const guint8 *ppbytes,
142 const guint passLength,
144 const size_t ssidLength,
145 const INT iterations,
151 * It calculates the passphrase-to-PSK mapping reccomanded for use with
152 * RSNAs. This implementation uses the PBKDF2 method defined in the RFC
154 * @param password [IN] pointer to a password (sequence of between 8 and
155 * 63 ASCII encoded characters)
156 * @param ssid [IN] pointer to the SSID string encoded in max 32 ASCII
158 * @param output [OUT] calculated PSK (to use as PMK in WPA)
160 * Described in 802.11i-2004, page 165
162 static INT AirPDcapRsnaPwd2Psk(
163 const CHAR *passphrase,
165 const size_t ssidLength,
169 static INT AirPDcapRsnaMng(
171 guint mac_header_len,
173 PAIRPDCAP_KEY_ITEM key,
174 AIRPDCAP_SEC_ASSOCIATION *sa,
178 static INT AirPDcapWepMng(
179 PAIRPDCAP_CONTEXT ctx,
181 guint mac_header_len,
183 PAIRPDCAP_KEY_ITEM key,
184 AIRPDCAP_SEC_ASSOCIATION *sa,
188 static INT AirPDcapRsna4WHandshake(
189 PAIRPDCAP_CONTEXT ctx,
191 AIRPDCAP_SEC_ASSOCIATION *sa,
192 PAIRPDCAP_KEY_ITEM key,
196 * It checks whether the specified key is corrected or not.
198 * For a standard WEP key the length will be changed to the standard
199 * length, and the type changed in a generic WEP key.
200 * @param key [IN] pointer to the key to validate
202 * - TRUE: the key contains valid fields and values
203 * - FALSE: the key has some invalid field or value
205 static INT AirPDcapValidateKey(
206 PAIRPDCAP_KEY_ITEM key)
209 static INT AirPDcapRsnaMicCheck(
212 UCHAR KCK[AIRPDCAP_WPA_KCK_LEN],
217 * @param ctx [IN] pointer to the current context
218 * @param id [IN] id of the association (composed by BSSID and MAC of
221 * - index of the Security Association structure if found
222 * - -1, if the specified addresses pair BSSID-STA MAC has not been found
224 static INT AirPDcapGetSa(
225 PAIRPDCAP_CONTEXT ctx,
226 AIRPDCAP_SEC_ASSOCIATION_ID *id)
229 static INT AirPDcapStoreSa(
230 PAIRPDCAP_CONTEXT ctx,
231 AIRPDCAP_SEC_ASSOCIATION_ID *id)
234 static const UCHAR * AirPDcapGetStaAddress(
235 const AIRPDCAP_MAC_FRAME_ADDR4 *frame)
238 static const UCHAR * AirPDcapGetBssidAddress(
239 const AIRPDCAP_MAC_FRAME_ADDR4 *frame)
242 static void AirPDcapRsnaPrfX(
243 AIRPDCAP_SEC_ASSOCIATION *sa,
245 const UCHAR snonce[32],
246 const INT x, /* for TKIP 512, for CCMP 384 */
254 /****************************************************************************/
256 /****************************************************************************/
257 /* Exported function definitions */
263 const guint8 broadcast_mac[] = { 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF };
266 /* NOTE : this assumes the WPA RSN IE format. If it were to be a generic RSN IE, then
267 we would need to change the structure since it could be variable length depending on the number
268 of unicast OUI and auth OUI. */
274 guint8 multicastOUI[4];
275 guint16 iUnicastCount; /* this should always be 1 for WPA client */
276 guint8 unicastOUI[4];
277 guint16 iAuthCount; /* this should always be 1 for WPA client */
282 #define EAPKEY_MIC_LEN 16 /* length of the MIC key for EAPoL_Key packet's MIC using MD5 */
287 guint8 key_information[2]; /* Make this an array to avoid alignment issues */
288 guint8 key_length[2]; /* Make this an array to avoid alignment issues */
289 guint8 replay_counter[8];
290 guint8 key_nonce[NONCE_LEN];
292 guint8 key_sequence_counter[8]; /* also called the RSC */
294 guint8 key_mic[EAPKEY_MIC_LEN];
295 guint8 key_data_len[2]; /* Make this an array rather than a U16 to avoid alignment shifting */
296 guint8 ie[sizeof(RSN_IE)]; /* Make this an array to avoid alignment issues */
297 } EAPOL_RSN_KEY, * P_EAPOL_RSN_KEY;
301 /* A note about some limitations with the WPA decryption:
303 Unless someone takes the time to restructure the current method used for maintaining decryption keys, there
304 will be some anomalies observed when using the decryption feature.
306 Currently, there is only one pairwise (unicast) key and one group (broadcast) key saved for each security association
307 (SA). As a result, if a wireless sniffer session captures the traffic of a station (STA) associating with an AP
308 more than once, or captures a STA roaming, then you will not be able to arbitrarilly click on different encrypted
309 packets in the trace and observe their internal decrypted structure. This is because when you click on a packet,
310 Wireshark immediately performs the decryption routine with whatever the last key used was. It does not maintain a
311 cache of all the keys that were used by this STA/AP pairing.
313 However, if you are just looking at the summary lines of a capture, it will appear that everything was decrypted properly.
314 This is because when first performing a capture or initially reading a capture file, Wireshark will first
315 process the packets in order. As it encounters new EAPOL packets, it will update its internal key list with the
316 newfound key. Then it will use that key for decrypting subsequent packets. Each time a new key is found, the old key
317 is overwritten. So, if you then click on a packet that was previously decrypted properly, it might suddenly no longer
318 be decrypted because a later EAPOL key had caused the internal decryption key to be updated.
320 For broadcast packets, there is a clunky work-around. If the AP is using group-key rotation, you simply have to find the appropriate
321 EAPOL group key packet (usually size is 211 bytes and will have a protocol type of EAPOL and Info field of Key). If you click on it
322 and then click on the broadcast packet you are trying to decrypt, the packet will be decrypted properly. By first
323 clicking on the EAPOL packet for the group-key, you will force Wireshark to parse that packet and load the group-key it
324 contains. That group key will then be used for decrypting all subsequent broadcast packets you click on.
326 Ideally, it would be best to maintain an expanding list of SA keys. Perhaps we could associate packet number ranges
327 that they apply to. Then, whenever we need to decrypt a packet, we can determine which key to use based on whether
328 it is broadcast or unicast and within what packet number range it falls.
330 Either that, or store two versions of encrypted packets - the orginal packet and it's successfully
331 decrypted version. Then Wireshark wouldn't have to decrypt packets on the fly if they were already successfully decrypted.
337 AirPDcapDecryptWPABroadcastKey(P_EAPOL_RSN_KEY pEAPKey, guint8 *decryption_key, PAIRPDCAP_SEC_ASSOCIATION sa)
341 guint8 *szEncryptedKey;
343 static AIRPDCAP_KEY_ITEM dummy_key; /* needed in case AirPDcapRsnaMng() wants the key structure */
345 /* We skip verifying the MIC of the key. If we were implementing a WPA supplicant we'd want to verify, but for a sniffer it's not needed. */
347 /* Preparation for decrypting the group key - determine group key data length */
348 /* depending on whether it's a TKIP or AES encryption key */
349 key_version = AIRPDCAP_EAP_KEY_DESCR_VER(pEAPKey->key_information[1]);
350 if (key_version == AIRPDCAP_WPA_KEY_VER_NOT_CCMP){
352 key_len = pntohs(pEAPKey->key_length);
353 }else if (key_version == AIRPDCAP_WPA_KEY_VER_AES_CCMP){
355 key_len = pntohs(pEAPKey->key_data_len);
357 if (key_len > sizeof(RSN_IE) || key_len == 0) { /* Don't read past the end of pEAPKey->ie */
361 /* Encrypted key is in the information element field of the EAPOL key packet */
362 szEncryptedKey = g_memdup(pEAPKey->ie, key_len);
364 DEBUG_DUMP("Encrypted Broadcast key:", szEncryptedKey, key_len);
365 DEBUG_DUMP("KeyIV:", pEAPKey->key_iv, 16);
366 DEBUG_DUMP("decryption_key:", decryption_key, 16);
368 /* Build the full decryption key based on the IV and part of the pairwise key */
369 memcpy(new_key, pEAPKey->key_iv, 16);
370 memcpy(new_key+16, decryption_key, 16);
371 DEBUG_DUMP("FullDecrKey:", new_key, 32);
373 if (key_version == AIRPDCAP_WPA_KEY_VER_NOT_CCMP){
376 /* Per 802.11i, Draft 3.0 spec, section 8.5.2, p. 97, line 4-8, */
377 /* group key is decrypted using RC4. Concatenate the IV with the 16 byte EK (PTK+16) to get the decryption key */
379 rc4_state_struct rc4_state;
380 crypt_rc4_init(&rc4_state, new_key, sizeof(new_key));
382 /* Do dummy 256 iterations of the RC4 algorithm (per 802.11i, Draft 3.0, p. 97 line 6) */
383 crypt_rc4(&rc4_state, dummy, 256);
384 crypt_rc4(&rc4_state, szEncryptedKey, key_len);
386 } else if (key_version == AIRPDCAP_WPA_KEY_VER_AES_CCMP){
391 guint8 *decrypted_data;
393 /* This storage is needed for the AES_unwrap function */
394 decrypted_data = (guint8 *) g_malloc(key_len);
396 AES_unwrap(decryption_key, 16, szEncryptedKey, key_len, decrypted_data);
398 /* With WPA2 what we get after Broadcast Key decryption is an actual RSN structure.
399 The key itself is stored as a GTK KDE
400 WPA2 IE (1 byte) id = 0xdd, length (1 byte), GTK OUI (4 bytes), key index (1 byte) and 1 reserved byte. Thus we have to
401 pass pointer to the actual key with 8 bytes offset */
405 while(key_index < key_len && !key_found){
409 rsn_id = decrypted_data[key_index];
412 key_index += decrypted_data[key_index+1]+2;
419 /* Skip over the GTK header info, and don't copy past the end of the encrypted data */
420 memcpy(szEncryptedKey, decrypted_data+key_index+8, key_len-key_index-8);
423 g_free(decrypted_data);
426 /* Decrypted key is now in szEncryptedKey with len of key_len */
427 DEBUG_DUMP("Broadcast key:", szEncryptedKey, key_len);
429 /* Load the proper key material info into the SA */
430 sa->key = &dummy_key; /* we just need key to be not null because it is checked in AirPDcapRsnaMng(). The WPA key materials are actually in the .wpa structure */
432 sa->wpa.key_ver = key_version;
434 /* Since this is a GTK and it's size is only 32 bytes (vs. the 64 byte size of a PTK), we fake it and put it in at a 32-byte offset so the */
435 /* AirPDcapRsnaMng() function will extract the right piece of the GTK for decryption. (The first 16 bytes of the GTK are used for decryption.) */
436 memset(sa->wpa.ptk, 0, sizeof(sa->wpa.ptk));
437 memcpy(sa->wpa.ptk+32, szEncryptedKey, key_len);
438 g_free(szEncryptedKey);
442 /* Return a pointer the the requested SA. If it doesn't exist create it. */
443 PAIRPDCAP_SEC_ASSOCIATION
445 PAIRPDCAP_CONTEXT ctx,
446 AIRPDCAP_SEC_ASSOCIATION_ID *id)
450 /* search for a cached Security Association for supplied BSSID and STA MAC */
451 if ((sa_index=AirPDcapGetSa(ctx, id))==-1) {
452 /* create a new Security Association if it doesn't currently exist */
453 if ((sa_index=AirPDcapStoreSa(ctx, id))==-1) {
457 /* get the Security Association structure */
458 return &ctx->sa[sa_index];
461 #define GROUP_KEY_PAYLOAD_LEN (8+4+sizeof(EAPOL_RSN_KEY))
462 INT AirPDcapScanForGroupKey(
463 PAIRPDCAP_CONTEXT ctx,
465 const guint mac_header_len,
469 const UCHAR *address;
470 AIRPDCAP_SEC_ASSOCIATION_ID id;
472 PAIRPDCAP_SEC_ASSOCIATION sta_sa;
473 PAIRPDCAP_SEC_ASSOCIATION sa;
475 const guint8 dot1x_header[] = {
476 0xAA, /* DSAP=SNAP */
477 0xAA, /* SSAP=SNAP */
478 0x03, /* Control field=Unnumbered frame */
479 0x00, 0x00, 0x00, /* Org. code=encaps. Ethernet */
480 0x88, 0x8E /* Type: 802.1X authentication */
483 P_EAPOL_RSN_KEY pEAPKey;
488 AIRPDCAP_DEBUG_TRACE_START("AirPDcapScanForGroupKey");
490 if (mac_header_len + GROUP_KEY_PAYLOAD_LEN < tot_len) {
491 AIRPDCAP_DEBUG_PRINT_LINE("AirPDcapScanForGroupKey", "Message too short", AIRPDCAP_DEBUG_LEVEL_3);
492 return AIRPDCAP_RET_NO_VALID_HANDSHAKE;
495 /* cache offset in the packet data */
496 offset = mac_header_len;
498 /* check if the packet has an LLC header and the packet is 802.1X authentication (IEEE 802.1X-2004, pg. 24) */
499 if (memcmp(data+offset, dot1x_header, 8) == 0) {
501 AIRPDCAP_DEBUG_PRINT_LINE("AirPDcapScanForGroupKey", "Authentication: EAPOL packet", AIRPDCAP_DEBUG_LEVEL_3);
503 /* skip LLC header */
507 /* check if the packet is a EAPOL-Key (0x03) (IEEE 802.1X-2004, pg. 25) */
508 if (data[offset+1]!=3) {
509 AIRPDCAP_DEBUG_PRINT_LINE("AirPDcapScanForGroupKey", "Not EAPOL-Key", AIRPDCAP_DEBUG_LEVEL_3);
510 return AIRPDCAP_RET_NO_VALID_HANDSHAKE;
513 /* get and check the body length (IEEE 802.1X-2004, pg. 25) */
514 bodyLength=pntohs(data+offset+2);
515 if ((tot_len-offset-4) < bodyLength) {
516 AIRPDCAP_DEBUG_PRINT_LINE("AirPDcapScanForGroupKey", "EAPOL body too short", AIRPDCAP_DEBUG_LEVEL_3);
517 return AIRPDCAP_RET_NO_VALID_HANDSHAKE;
520 /* skip EAPOL MPDU and go to the first byte of the body */
523 pEAPKey = (P_EAPOL_RSN_KEY) (data+offset);
525 /* check if the key descriptor type is valid (IEEE 802.1X-2004, pg. 27) */
526 if (/*pEAPKey->type!=0x1 &&*/ /* RC4 Key Descriptor Type (deprecated) */
527 pEAPKey->type != AIRPDCAP_RSN_WPA2_KEY_DESCRIPTOR && /* IEEE 802.11 Key Descriptor Type (WPA2) */
528 pEAPKey->type != AIRPDCAP_RSN_WPA_KEY_DESCRIPTOR) /* 254 = RSN_KEY_DESCRIPTOR - WPA, */
530 AIRPDCAP_DEBUG_PRINT_LINE("AirPDcapScanForGroupKey", "Not valid key descriptor type", AIRPDCAP_DEBUG_LEVEL_3);
531 return AIRPDCAP_RET_NO_VALID_HANDSHAKE;
534 /* start with descriptor body */
537 /* Verify the bitfields: Key = 0(groupwise) Mic = 1 Ack = 1 Secure = 1 */
538 if (AIRPDCAP_EAP_KEY(data[offset+1])!=0 ||
539 AIRPDCAP_EAP_ACK(data[offset+1])!=1 ||
540 AIRPDCAP_EAP_MIC(data[offset]) != 1 ||
541 AIRPDCAP_EAP_SEC(data[offset]) != 1){
543 AIRPDCAP_DEBUG_PRINT_LINE("AirPDcapScanForGroupKey", "Key bitfields not correct", AIRPDCAP_DEBUG_LEVEL_3);
544 return AIRPDCAP_RET_NO_VALID_HANDSHAKE;
548 if ( (address=AirPDcapGetBssidAddress((const AIRPDCAP_MAC_FRAME_ADDR4 *)(data))) != NULL) {
549 memcpy(id.bssid, address, AIRPDCAP_MAC_LEN);
551 sprintf(msgbuf, "BSSID: %2X.%2X.%2X.%2X.%2X.%2X\t", id.bssid[0],id.bssid[1],id.bssid[2],id.bssid[3],id.bssid[4],id.bssid[5]);
553 AIRPDCAP_DEBUG_PRINT_LINE("AirPDcapScanForGroupKey", msgbuf, AIRPDCAP_DEBUG_LEVEL_3);
555 AIRPDCAP_DEBUG_PRINT_LINE("AirPDcapScanForGroupKey", "BSSID not found", AIRPDCAP_DEBUG_LEVEL_5);
556 return AIRPDCAP_RET_REQ_DATA;
559 /* force STA address to be the broadcast MAC so we create an SA for the groupkey */
560 memcpy(id.sta, broadcast_mac, AIRPDCAP_MAC_LEN);
562 /* get the Security Association structure for the broadcast MAC and AP */
563 sa = AirPDcapGetSaPtr(ctx, &id);
565 return AIRPDCAP_RET_UNSUCCESS;
568 /* Get the SA for the STA, since we need its pairwise key to decrpyt the group key */
570 /* get STA address */
571 if ( (address=AirPDcapGetStaAddress((const AIRPDCAP_MAC_FRAME_ADDR4 *)(data))) != NULL) {
572 memcpy(id.sta, address, AIRPDCAP_MAC_LEN);
574 sprintf(msgbuf, "ST_MAC: %2X.%2X.%2X.%2X.%2X.%2X\t", id.sta[0],id.sta[1],id.sta[2],id.sta[3],id.sta[4],id.sta[5]);
576 AIRPDCAP_DEBUG_PRINT_LINE("AirPDcapScanForGroupKey", msgbuf, AIRPDCAP_DEBUG_LEVEL_3);
578 AIRPDCAP_DEBUG_PRINT_LINE("AirPDcapScanForGroupKey", "SA not found", AIRPDCAP_DEBUG_LEVEL_5);
579 return AIRPDCAP_RET_REQ_DATA;
582 sta_sa = AirPDcapGetSaPtr(ctx, &id);
584 return AIRPDCAP_RET_UNSUCCESS;
587 /* Extract the group key and install it in the SA */
588 AirPDcapDecryptWPABroadcastKey(pEAPKey, sta_sa->wpa.ptk+16, sa);
591 AIRPDCAP_DEBUG_PRINT_LINE("AirPDcapScanForGroupKey", "Skipping: not an EAPOL packet", AIRPDCAP_DEBUG_LEVEL_3);
594 AIRPDCAP_DEBUG_TRACE_END("AirPDcapScanForGroupKey");
599 INT AirPDcapPacketProcess(
600 PAIRPDCAP_CONTEXT ctx,
602 const guint mac_header_len,
606 PAIRPDCAP_KEY_ITEM key,
607 gboolean mngHandshake,
610 const UCHAR *address;
611 AIRPDCAP_SEC_ASSOCIATION_ID id;
612 PAIRPDCAP_SEC_ASSOCIATION sa;
615 const guint8 dot1x_header[] = {
616 0xAA, /* DSAP=SNAP */
617 0xAA, /* SSAP=SNAP */
618 0x03, /* Control field=Unnumbered frame */
619 0x00, 0x00, 0x00, /* Org. code=encaps. Ethernet */
620 0x88, 0x8E /* Type: 802.1X authentication */
627 AIRPDCAP_DEBUG_TRACE_START("AirPDcapPacketProcess");
630 AIRPDCAP_DEBUG_PRINT_LINE("AirPDcapPacketProcess", "NULL context", AIRPDCAP_DEBUG_LEVEL_5);
631 AIRPDCAP_DEBUG_TRACE_END("AirPDcapPacketProcess");
632 return AIRPDCAP_RET_UNSUCCESS;
634 if (data==NULL || tot_len==0) {
635 AIRPDCAP_DEBUG_PRINT_LINE("AirPDcapPacketProcess", "NULL data or length=0", AIRPDCAP_DEBUG_LEVEL_5);
636 AIRPDCAP_DEBUG_TRACE_END("AirPDcapPacketProcess");
637 return AIRPDCAP_RET_UNSUCCESS;
640 /* check if the packet is of data type */
641 if (AIRPDCAP_TYPE(data[0])!=AIRPDCAP_TYPE_DATA) {
642 AIRPDCAP_DEBUG_PRINT_LINE("AirPDcapPacketProcess", "not data packet", AIRPDCAP_DEBUG_LEVEL_5);
643 return AIRPDCAP_RET_NO_DATA;
646 /* check correct packet size, to avoid wrong elaboration of encryption algorithms */
647 if (tot_len < (UINT)(mac_header_len+AIRPDCAP_CRYPTED_DATA_MINLEN)) {
648 AIRPDCAP_DEBUG_PRINT_LINE("AirPDcapPacketProcess", "minimum length violated", AIRPDCAP_DEBUG_LEVEL_5);
649 return AIRPDCAP_RET_WRONG_DATA_SIZE;
653 if ( (address=AirPDcapGetBssidAddress((const AIRPDCAP_MAC_FRAME_ADDR4 *)(data))) != NULL) {
654 memcpy(id.bssid, address, AIRPDCAP_MAC_LEN);
656 sprintf(msgbuf, "BSSID: %2X.%2X.%2X.%2X.%2X.%2X\t", id.bssid[0],id.bssid[1],id.bssid[2],id.bssid[3],id.bssid[4],id.bssid[5]);
658 AIRPDCAP_DEBUG_PRINT_LINE("AirPDcapPacketProcess", msgbuf, AIRPDCAP_DEBUG_LEVEL_3);
660 AIRPDCAP_DEBUG_PRINT_LINE("AirPDcapPacketProcess", "BSSID not found", AIRPDCAP_DEBUG_LEVEL_5);
661 return AIRPDCAP_RET_REQ_DATA;
664 /* get STA address */
665 if ( (address=AirPDcapGetStaAddress((const AIRPDCAP_MAC_FRAME_ADDR4 *)(data))) != NULL) {
666 memcpy(id.sta, address, AIRPDCAP_MAC_LEN);
668 sprintf(msgbuf, "ST_MAC: %2X.%2X.%2X.%2X.%2X.%2X\t", id.sta[0],id.sta[1],id.sta[2],id.sta[3],id.sta[4],id.sta[5]);
670 AIRPDCAP_DEBUG_PRINT_LINE("AirPDcapPacketProcess", msgbuf, AIRPDCAP_DEBUG_LEVEL_3);
672 AIRPDCAP_DEBUG_PRINT_LINE("AirPDcapPacketProcess", "SA not found", AIRPDCAP_DEBUG_LEVEL_5);
673 return AIRPDCAP_RET_REQ_DATA;
676 /* get the Security Association structure for the STA and AP */
677 sa = AirPDcapGetSaPtr(ctx, &id);
679 return AIRPDCAP_RET_UNSUCCESS;
682 /* cache offset in the packet data (to scan encryption data) */
683 offset = mac_header_len;
685 /* check if data is encrypted (use the WEP bit in the Frame Control field) */
686 if (AIRPDCAP_WEP(data[1])==0)
689 /* data is sent in cleartext, check if is an authentication message or end the process */
690 AIRPDCAP_DEBUG_PRINT_LINE("AirPDcapPacketProcess", "Unencrypted data", AIRPDCAP_DEBUG_LEVEL_3);
692 /* check if the packet as an LLC header and the packet is 802.1X authentication (IEEE 802.1X-2004, pg. 24) */
693 if (memcmp(data+offset, dot1x_header, 8) == 0) {
694 AIRPDCAP_DEBUG_PRINT_LINE("AirPDcapPacketProcess", "Authentication: EAPOL packet", AIRPDCAP_DEBUG_LEVEL_3);
696 /* skip LLC header */
699 /* check the version of the EAPOL protocol used (IEEE 802.1X-2004, pg. 24) */
700 /* TODO EAPOL protocol version to check? */
701 /*if (data[offset]!=2) {
702 AIRPDCAP_DEBUG_PRINT_LINE("EAPOL protocol version not recognized", AIRPDCAP_DEBUG_LEVEL_5);
703 return AIRPDCAP_RET_NO_VALID_HANDSHAKE;
706 /* check if the packet is a EAPOL-Key (0x03) (IEEE 802.1X-2004, pg. 25) */
707 if (data[offset+1]!=3) {
708 AIRPDCAP_DEBUG_PRINT_LINE("AirPDcapPacketProcess", "Not EAPOL-Key", AIRPDCAP_DEBUG_LEVEL_5);
709 return AIRPDCAP_RET_NO_VALID_HANDSHAKE;
712 /* get and check the body length (IEEE 802.1X-2004, pg. 25) */
713 bodyLength=pntohs(data+offset+2);
714 if ((tot_len-offset-4) < bodyLength) {
715 AIRPDCAP_DEBUG_PRINT_LINE("AirPDcapPacketProcess", "EAPOL body too short", AIRPDCAP_DEBUG_LEVEL_5);
716 return AIRPDCAP_RET_NO_VALID_HANDSHAKE;
719 /* skip EAPOL MPDU and go to the first byte of the body */
722 /* check if the key descriptor type is valid (IEEE 802.1X-2004, pg. 27) */
723 if (/*data[offset]!=0x1 &&*/ /* RC4 Key Descriptor Type (deprecated) */
724 data[offset]!=0x2 && /* IEEE 802.11 Key Descriptor Type */
725 data[offset]!=0xFE) /* TODO what's this value??? */
727 AIRPDCAP_DEBUG_PRINT_LINE("AirPDcapPacketProcess", "Not valid key descriptor type", AIRPDCAP_DEBUG_LEVEL_5);
728 return AIRPDCAP_RET_NO_VALID_HANDSHAKE;
731 /* start with descriptor body */
734 /* manage the 4-way handshake to define the key */
735 return AirPDcapRsna4WHandshake(ctx, data, sa, key, offset);
737 /* cleartext message, not authentication */
738 AIRPDCAP_DEBUG_PRINT_LINE("AirPDcapPacketProcess", "No authentication data", AIRPDCAP_DEBUG_LEVEL_5);
739 return AIRPDCAP_RET_NO_DATA_ENCRYPTED;
745 if (decrypt_data==NULL)
746 return AIRPDCAP_RET_UNSUCCESS;
748 /* create new header and data to modify */
749 *decrypt_len = tot_len;
750 memcpy(decrypt_data, data, *decrypt_len);
753 AIRPDCAP_DEBUG_PRINT_LINE("AirPDcapPacketProcess", "Encrypted data", AIRPDCAP_DEBUG_LEVEL_3);
755 /* check the Extension IV to distinguish between WEP encryption and WPA encryption */
756 /* refer to IEEE 802.11i-2004, 8.2.1.2, pag.35 for WEP, */
757 /* IEEE 802.11i-2004, 8.3.2.2, pag. 45 for TKIP, */
758 /* IEEE 802.11i-2004, 8.3.3.2, pag. 57 for CCMP */
759 if (AIRPDCAP_EXTIV(data[offset+3])==0) {
760 AIRPDCAP_DEBUG_PRINT_LINE("AirPDcapPacketProcess", "WEP encryption", AIRPDCAP_DEBUG_LEVEL_3);
761 return AirPDcapWepMng(ctx, decrypt_data, mac_header_len, decrypt_len, key, sa, offset);
764 AIRPDCAP_DEBUG_PRINT_LINE("AirPDcapPacketProcess", "TKIP or CCMP encryption", AIRPDCAP_DEBUG_LEVEL_3);
766 /* If index >= 1, then use the group key. This will not work if the AP is using
767 more than one group key simultaneously. I've not seen this in practice, however. Usually an AP
768 will rotate between the two key index values of 1 and 2 whenever it needs to change the group key to be used. */
769 if (AIRPDCAP_KEY_INDEX(data[offset+3])>=1){
771 AIRPDCAP_DEBUG_PRINT_LINE("AirPDcapPacketProcess", "The key index = 1. This is encrypted with a group key.", AIRPDCAP_DEBUG_LEVEL_3);
773 /* force STA address to broadcast MAC so we load the SA for the groupkey */
774 memcpy(id.sta, broadcast_mac, AIRPDCAP_MAC_LEN);
777 sprintf(msgbuf, "ST_MAC: %2X.%2X.%2X.%2X.%2X.%2X\t", id.sta[0],id.sta[1],id.sta[2],id.sta[3],id.sta[4],id.sta[5]);
778 AIRPDCAP_DEBUG_PRINT_LINE("AirPDcapPacketProcess", msgbuf, AIRPDCAP_DEBUG_LEVEL_3);
781 /* search for a cached Security Association for current BSSID and broadcast MAC */
782 sa = AirPDcapGetSaPtr(ctx, &id);
784 return AIRPDCAP_RET_UNSUCCESS;
788 /* Decrypt the packet using the appropriate SA */
789 status = AirPDcapRsnaMng(decrypt_data, mac_header_len, decrypt_len, key, sa, offset);
791 /* If we successfully decrypted a packet, scan it to see if it contains a group key handshake.
792 The group key handshake could be sent at any time the AP wants to change the key (such as when
793 it is using key rotation) so we must scan every packet. */
794 if (status == AIRPDCAP_RET_SUCCESS)
795 AirPDcapScanForGroupKey(ctx, decrypt_data, mac_header_len, *decrypt_len);
801 return AIRPDCAP_RET_UNSUCCESS;
805 PAIRPDCAP_CONTEXT ctx,
806 AIRPDCAP_KEY_ITEM keys[],
807 const size_t keys_nr)
811 AIRPDCAP_DEBUG_TRACE_START("AirPDcapSetKeys");
813 if (ctx==NULL || keys==NULL) {
814 AIRPDCAP_DEBUG_PRINT_LINE("AirPDcapSetKeys", "NULL context or NULL keys array", AIRPDCAP_DEBUG_LEVEL_3);
815 AIRPDCAP_DEBUG_TRACE_END("AirPDcapSetKeys");
819 if (keys_nr>AIRPDCAP_MAX_KEYS_NR) {
820 AIRPDCAP_DEBUG_PRINT_LINE("AirPDcapSetKeys", "Keys number greater than maximum", AIRPDCAP_DEBUG_LEVEL_3);
821 AIRPDCAP_DEBUG_TRACE_END("AirPDcapSetKeys");
825 /* clean key and SA collections before setting new ones */
826 AirPDcapInitContext(ctx);
828 /* check and insert keys */
829 for (i=0, success=0; i<(INT)keys_nr; i++) {
830 if (AirPDcapValidateKey(keys+i)==TRUE) {
831 if (keys[i].KeyType==AIRPDCAP_KEY_TYPE_WPA_PWD) {
832 AIRPDCAP_DEBUG_PRINT_LINE("AirPDcapSetKeys", "Set a WPA-PWD key", AIRPDCAP_DEBUG_LEVEL_4);
833 AirPDcapRsnaPwd2Psk(keys[i].UserPwd.Passphrase, keys[i].UserPwd.Ssid, keys[i].UserPwd.SsidLen, keys[i].KeyData.Wpa.Psk);
836 else if (keys[i].KeyType==AIRPDCAP_KEY_TYPE_WPA_PMK) {
837 AIRPDCAP_DEBUG_PRINT_LINE("AirPDcapSetKeys", "Set a WPA-PMK key", AIRPDCAP_DEBUG_LEVEL_4);
838 } else if (keys[i].KeyType==AIRPDCAP_KEY_TYPE_WEP) {
839 AIRPDCAP_DEBUG_PRINT_LINE("AirPDcapSetKeys", "Set a WEP key", AIRPDCAP_DEBUG_LEVEL_4);
841 AIRPDCAP_DEBUG_PRINT_LINE("AirPDcapSetKeys", "Set a key", AIRPDCAP_DEBUG_LEVEL_4);
844 memcpy(&ctx->keys[success], &keys[i], sizeof(keys[i]));
849 ctx->keys_nr=success;
851 AIRPDCAP_DEBUG_TRACE_END("AirPDcapSetKeys");
857 PAIRPDCAP_CONTEXT ctx)
859 AIRPDCAP_DEBUG_TRACE_START("AirPDcapCleanKeys");
862 AIRPDCAP_DEBUG_PRINT_LINE("AirPDcapCleanKeys", "NULL context", AIRPDCAP_DEBUG_LEVEL_5);
863 AIRPDCAP_DEBUG_TRACE_END("AirPDcapCleanKeys");
867 memset(ctx->keys, 0, sizeof(AIRPDCAP_KEY_ITEM) * AIRPDCAP_MAX_KEYS_NR);
871 AIRPDCAP_DEBUG_PRINT_LINE("AirPDcapCleanKeys", "Keys collection cleaned!", AIRPDCAP_DEBUG_LEVEL_5);
872 AIRPDCAP_DEBUG_TRACE_END("AirPDcapCleanKeys");
876 const PAIRPDCAP_CONTEXT ctx,
877 AIRPDCAP_KEY_ITEM keys[],
878 const size_t keys_nr)
882 AIRPDCAP_DEBUG_TRACE_START("AirPDcapGetKeys");
885 AIRPDCAP_DEBUG_PRINT_LINE("AirPDcapGetKeys", "NULL context", AIRPDCAP_DEBUG_LEVEL_5);
886 AIRPDCAP_DEBUG_TRACE_END("AirPDcapGetKeys");
888 } else if (keys==NULL) {
889 AIRPDCAP_DEBUG_PRINT_LINE("AirPDcapGetKeys", "NULL keys array", AIRPDCAP_DEBUG_LEVEL_5);
890 AIRPDCAP_DEBUG_TRACE_END("AirPDcapGetKeys");
891 return (INT)ctx->keys_nr;
893 for (i=0, j=0; i<ctx->keys_nr && i<keys_nr && i<AIRPDCAP_MAX_KEYS_NR; i++) {
894 memcpy(&keys[j], &ctx->keys[i], sizeof(keys[j]));
896 AIRPDCAP_DEBUG_PRINT_LINE("AirPDcapGetKeys", "Got a key", AIRPDCAP_DEBUG_LEVEL_5);
899 AIRPDCAP_DEBUG_TRACE_END("AirPDcapGetKeys");
905 * XXX - This won't be reliable if a packet containing SSID "B" shows
906 * up in the middle of a 4-way handshake for SSID "A".
907 * We should probably use a small array or hash table to keep multiple
910 INT AirPDcapSetLastSSID(
911 PAIRPDCAP_CONTEXT ctx,
915 if (!ctx || !pkt_ssid || pkt_ssid_len < 1 || pkt_ssid_len > WPA_SSID_MAX_SIZE)
916 return AIRPDCAP_RET_UNSUCCESS;
918 memcpy(ctx->pkt_ssid, pkt_ssid, pkt_ssid_len);
919 ctx->pkt_ssid_len = pkt_ssid_len;
921 return AIRPDCAP_RET_SUCCESS;
924 INT AirPDcapInitContext(
925 PAIRPDCAP_CONTEXT ctx)
927 AIRPDCAP_DEBUG_TRACE_START("AirPDcapInitContext");
930 AIRPDCAP_DEBUG_PRINT_LINE("AirPDcapInitContext", "NULL context", AIRPDCAP_DEBUG_LEVEL_5);
931 AIRPDCAP_DEBUG_TRACE_END("AirPDcapInitContext");
932 return AIRPDCAP_RET_UNSUCCESS;
935 AirPDcapCleanKeys(ctx);
937 ctx->first_free_index=0;
940 ctx->pkt_ssid_len = 0;
942 memset(ctx->sa, 0, AIRPDCAP_MAX_SEC_ASSOCIATIONS_NR * sizeof(AIRPDCAP_SEC_ASSOCIATION));
944 AIRPDCAP_DEBUG_PRINT_LINE("AirPDcapInitContext", "Context initialized!", AIRPDCAP_DEBUG_LEVEL_5);
945 AIRPDCAP_DEBUG_TRACE_END("AirPDcapInitContext");
946 return AIRPDCAP_RET_SUCCESS;
949 INT AirPDcapDestroyContext(
950 PAIRPDCAP_CONTEXT ctx)
952 AIRPDCAP_DEBUG_TRACE_START("AirPDcapDestroyContext");
955 AIRPDCAP_DEBUG_PRINT_LINE("AirPDcapDestroyContext", "NULL context", AIRPDCAP_DEBUG_LEVEL_5);
956 AIRPDCAP_DEBUG_TRACE_END("AirPDcapDestroyContext");
957 return AIRPDCAP_RET_UNSUCCESS;
960 AirPDcapCleanKeys(ctx);
962 ctx->first_free_index=0;
966 AIRPDCAP_DEBUG_PRINT_LINE("AirPDcapDestroyContext", "Context destroyed!", AIRPDCAP_DEBUG_LEVEL_5);
967 AIRPDCAP_DEBUG_TRACE_END("AirPDcapDestroyContext");
968 return AIRPDCAP_RET_SUCCESS;
975 /****************************************************************************/
977 /****************************************************************************/
978 /* Internal function definitions */
987 guint mac_header_len,
989 PAIRPDCAP_KEY_ITEM key,
990 AIRPDCAP_SEC_ASSOCIATION *sa,
996 AIRPDCAP_DEBUG_PRINT_LINE("AirPDcapRsnaMng", "No key associated", AIRPDCAP_DEBUG_LEVEL_3);
997 return AIRPDCAP_RET_REQ_DATA;
999 if (sa->validKey==FALSE) {
1000 AIRPDCAP_DEBUG_PRINT_LINE("AirPDcapRsnaMng", "Key not yet valid", AIRPDCAP_DEBUG_LEVEL_3);
1001 return AIRPDCAP_RET_UNSUCCESS;
1003 if (sa->wpa.key_ver==1) {
1004 /* CCMP -> HMAC-MD5 is the EAPOL-Key MIC, RC4 is the EAPOL-Key encryption algorithm */
1005 AIRPDCAP_DEBUG_PRINT_LINE("AirPDcapRsnaMng", "TKIP", AIRPDCAP_DEBUG_LEVEL_3);
1007 DEBUG_DUMP("ptk", sa->wpa.ptk, 64);
1008 DEBUG_DUMP("ptk portion used", AIRPDCAP_GET_TK(sa->wpa.ptk), 16);
1010 ret_value=AirPDcapTkipDecrypt(decrypt_data+offset, *decrypt_len-offset, decrypt_data+AIRPDCAP_TA_OFFSET, AIRPDCAP_GET_TK(sa->wpa.ptk));
1012 AIRPDCAP_DEBUG_PRINT_LINE("AirPDcapRsnaMng", "TKIP failed!", AIRPDCAP_DEBUG_LEVEL_3);
1016 AIRPDCAP_DEBUG_PRINT_LINE("AirPDcapRsnaMng", "TKIP DECRYPTED!!!", AIRPDCAP_DEBUG_LEVEL_3);
1017 /* remove MIC (8bytes) and ICV (4bytes) from the end of packet */
1020 /* AES-CCMP -> HMAC-SHA1-128 is the EAPOL-Key MIC, AES wep_key wrap is the EAPOL-Key encryption algorithm */
1021 AIRPDCAP_DEBUG_PRINT_LINE("AirPDcapRsnaMng", "CCMP", AIRPDCAP_DEBUG_LEVEL_3);
1023 ret_value=AirPDcapCcmpDecrypt(decrypt_data, mac_header_len, (INT)*decrypt_len, AIRPDCAP_GET_TK(sa->wpa.ptk));
1027 AIRPDCAP_DEBUG_PRINT_LINE("AirPDcapRsnaMng", "CCMP DECRYPTED!!!", AIRPDCAP_DEBUG_LEVEL_3);
1028 /* remove MIC (8bytes) from the end of packet */
1032 /* remove protection bit */
1033 decrypt_data[1]&=0xBF;
1035 /* remove TKIP/CCMP header */
1036 offset = mac_header_len;
1038 memcpy(decrypt_data+offset, decrypt_data+offset+8, *decrypt_len-offset);
1041 memcpy(key, sa->key, sizeof(AIRPDCAP_KEY_ITEM));
1043 if (sa->wpa.key_ver==AIRPDCAP_WPA_KEY_VER_NOT_CCMP)
1044 key->KeyType=AIRPDCAP_KEY_TYPE_TKIP;
1045 else if (sa->wpa.key_ver==AIRPDCAP_WPA_KEY_VER_AES_CCMP)
1046 key->KeyType=AIRPDCAP_KEY_TYPE_CCMP;
1049 return AIRPDCAP_RET_SUCCESS;
1054 PAIRPDCAP_CONTEXT ctx,
1055 UCHAR *decrypt_data,
1056 guint mac_header_len,
1058 PAIRPDCAP_KEY_ITEM key,
1059 AIRPDCAP_SEC_ASSOCIATION *sa,
1062 UCHAR wep_key[AIRPDCAP_WEP_KEY_MAXLEN+AIRPDCAP_WEP_IVLEN];
1066 AIRPDCAP_KEY_ITEM *tmp_key;
1067 UINT8 useCache=FALSE;
1068 UCHAR *try_data = ep_alloc(*decrypt_len);
1073 for (key_index=0; key_index<(INT)ctx->keys_nr; key_index++) {
1074 /* use the cached one, or try all keys */
1076 tmp_key=&ctx->keys[key_index];
1078 if (sa->key!=NULL && sa->key->KeyType==AIRPDCAP_KEY_TYPE_WEP) {
1079 AIRPDCAP_DEBUG_PRINT_LINE("AirPDcapWepMng", "Try cached WEP key...", AIRPDCAP_DEBUG_LEVEL_3);
1082 AIRPDCAP_DEBUG_PRINT_LINE("AirPDcapWepMng", "Cached key is not valid, try another WEP key...", AIRPDCAP_DEBUG_LEVEL_3);
1083 tmp_key=&ctx->keys[key_index];
1087 /* obviously, try only WEP keys... */
1088 if (tmp_key->KeyType==AIRPDCAP_KEY_TYPE_WEP)
1090 AIRPDCAP_DEBUG_PRINT_LINE("AirPDcapWepMng", "Try WEP key...", AIRPDCAP_DEBUG_LEVEL_3);
1092 memset(wep_key, 0, sizeof(wep_key));
1093 memcpy(try_data, decrypt_data, *decrypt_len);
1095 /* Costruct the WEP seed: copy the IV in first 3 bytes and then the WEP key (refer to 802-11i-2004, 8.2.1.4.3, pag. 36) */
1096 memcpy(wep_key, try_data+mac_header_len, AIRPDCAP_WEP_IVLEN);
1097 keylen=tmp_key->KeyData.Wep.WepKeyLen;
1098 memcpy(wep_key+AIRPDCAP_WEP_IVLEN, tmp_key->KeyData.Wep.WepKey, keylen);
1100 ret_value=AirPDcapWepDecrypt(wep_key,
1101 keylen+AIRPDCAP_WEP_IVLEN,
1102 try_data + (mac_header_len+AIRPDCAP_WEP_IVLEN+AIRPDCAP_WEP_KIDLEN),
1103 *decrypt_len-(mac_header_len+AIRPDCAP_WEP_IVLEN+AIRPDCAP_WEP_KIDLEN+AIRPDCAP_CRC_LEN));
1105 if (ret_value == AIRPDCAP_RET_SUCCESS)
1106 memcpy(decrypt_data, try_data, *decrypt_len);
1109 if (!ret_value && tmp_key->KeyType==AIRPDCAP_KEY_TYPE_WEP) {
1110 /* the tried key is the correct one, cached in the Security Association */
1115 memcpy(key, &sa->key, sizeof(AIRPDCAP_KEY_ITEM));
1116 key->KeyType=AIRPDCAP_KEY_TYPE_WEP;
1121 /* the cached key was not valid, try other keys */
1123 if (useCache==TRUE) {
1133 AIRPDCAP_DEBUG_PRINT_LINE("AirPDcapWepMng", "WEP DECRYPTED!!!", AIRPDCAP_DEBUG_LEVEL_3);
1135 /* remove ICV (4bytes) from the end of packet */
1138 /* remove protection bit */
1139 decrypt_data[1]&=0xBF;
1141 /* remove IC header */
1142 offset = mac_header_len;
1144 memcpy(decrypt_data+offset, decrypt_data+offset+AIRPDCAP_WEP_IVLEN+AIRPDCAP_WEP_KIDLEN, *decrypt_len-offset);
1146 return AIRPDCAP_RET_SUCCESS;
1149 /* Refer to IEEE 802.11i-2004, 8.5.3, pag. 85 */
1151 AirPDcapRsna4WHandshake(
1152 PAIRPDCAP_CONTEXT ctx,
1154 AIRPDCAP_SEC_ASSOCIATION *sa,
1155 PAIRPDCAP_KEY_ITEM key,
1158 AIRPDCAP_KEY_ITEM *tmp_key, pkt_key;
1161 UCHAR useCache=FALSE;
1162 UCHAR eapol[AIRPDCAP_EAPOL_MAX_LEN];
1168 /* a 4-way handshake packet use a Pairwise key type (IEEE 802.11i-2004, pg. 79) */
1169 if (AIRPDCAP_EAP_KEY(data[offset+1])!=1) {
1170 AIRPDCAP_DEBUG_PRINT_LINE("AirPDcapRsna4WHandshake", "Group/STAKey message (not used)", AIRPDCAP_DEBUG_LEVEL_5);
1171 return AIRPDCAP_RET_NO_VALID_HANDSHAKE;
1174 /* TODO timeouts? reauthentication? */
1176 /* TODO consider key-index */
1178 /* TODO considera Deauthentications */
1180 AIRPDCAP_DEBUG_PRINT_LINE("AirPDcapRsna4WHandshake", "4-way handshake...", AIRPDCAP_DEBUG_LEVEL_5);
1182 /* manage 4-way handshake packets; this step completes the 802.1X authentication process (IEEE 802.11i-2004, pag. 85) */
1184 /* message 1: Authenticator->Supplicant (Sec=0, Mic=0, Ack=1, Inst=0, Key=1(pairwise), KeyRSC=0, Nonce=ANonce, MIC=0) */
1185 if (AIRPDCAP_EAP_INST(data[offset+1])==0 &&
1186 AIRPDCAP_EAP_ACK(data[offset+1])==1 &&
1187 AIRPDCAP_EAP_MIC(data[offset])==0)
1189 AIRPDCAP_DEBUG_PRINT_LINE("AirPDcapRsna4WHandshake", "4-way handshake message 1", AIRPDCAP_DEBUG_LEVEL_3);
1191 /* On reception of Message 1, the Supplicant determines whether the Key Replay Counter field value has been */
1192 /* used before with the current PMKSA. If the Key Replay Counter field value is less than or equal to the current */
1193 /* local value, the Supplicant discards the message. */
1194 /* -> not checked, the Authenticator will be send another Message 1 (hopefully!) */
1196 /* save ANonce (from authenticator) to derive the PTK with the SNonce (from the 2 message) */
1197 memcpy(sa->wpa.nonce, data+offset+12, 32);
1199 /* get the Key Descriptor Version (to select algorithm used in decryption -CCMP or TKIP-) */
1200 sa->wpa.key_ver=AIRPDCAP_EAP_KEY_DESCR_VER(data[offset+1]);
1204 return AIRPDCAP_RET_SUCCESS_HANDSHAKE;
1207 /* message 2|4: Supplicant->Authenticator (Sec=0|1, Mic=1, Ack=0, Inst=0, Key=1(pairwise), KeyRSC=0, Nonce=SNonce|0, MIC=MIC(KCK,EAPOL)) */
1208 if (AIRPDCAP_EAP_INST(data[offset+1])==0 &&
1209 AIRPDCAP_EAP_ACK(data[offset+1])==0 &&
1210 AIRPDCAP_EAP_MIC(data[offset])==1)
1212 if (AIRPDCAP_EAP_SEC(data[offset])==0) {
1214 /* PATCH: some implementations set secure bit to 0 also in the 4th message */
1215 /* to recognize which message is this check if wep_key data length is 0 */
1216 /* in the 4th message */
1217 if (data[offset+92]!=0 || data[offset+93]!=0) {
1219 AIRPDCAP_DEBUG_PRINT_LINE("AirPDcapRsna4WHandshake", "4-way handshake message 2", AIRPDCAP_DEBUG_LEVEL_3);
1221 /* On reception of Message 2, the Authenticator checks that the key replay counter corresponds to the */
1222 /* outstanding Message 1. If not, it silently discards the message. */
1223 /* If the calculated MIC does not match the MIC that the Supplicant included in the EAPOL-Key frame, */
1224 /* the Authenticator silently discards Message 2. */
1225 /* -> not checked; the Supplicant will send another message 2 (hopefully!) */
1227 /* now you can derive the PTK */
1228 for (key_index=0; key_index<(INT)ctx->keys_nr || useCache; key_index++) {
1229 /* use the cached one, or try all keys */
1231 AIRPDCAP_DEBUG_PRINT_LINE("AirPDcapRsna4WHandshake", "Try WPA key...", AIRPDCAP_DEBUG_LEVEL_3);
1232 tmp_key=&ctx->keys[key_index];
1234 /* there is a cached key in the security association, if it's a WPA key try it... */
1235 if (sa->key!=NULL &&
1236 (sa->key->KeyType==AIRPDCAP_KEY_TYPE_WPA_PWD ||
1237 sa->key->KeyType==AIRPDCAP_KEY_TYPE_WPA_PSK ||
1238 sa->key->KeyType==AIRPDCAP_KEY_TYPE_WPA_PMK)) {
1239 AIRPDCAP_DEBUG_PRINT_LINE("AirPDcapRsna4WHandshake", "Try cached WPA key...", AIRPDCAP_DEBUG_LEVEL_3);
1242 AIRPDCAP_DEBUG_PRINT_LINE("AirPDcapRsna4WHandshake", "Cached key is of a wrong type, try WPA key...", AIRPDCAP_DEBUG_LEVEL_3);
1243 tmp_key=&ctx->keys[key_index];
1247 /* obviously, try only WPA keys... */
1248 if (tmp_key->KeyType==AIRPDCAP_KEY_TYPE_WPA_PWD ||
1249 tmp_key->KeyType==AIRPDCAP_KEY_TYPE_WPA_PSK ||
1250 tmp_key->KeyType==AIRPDCAP_KEY_TYPE_WPA_PMK)
1252 if (tmp_key->KeyType == AIRPDCAP_KEY_TYPE_WPA_PWD && tmp_key->UserPwd.SsidLen == 0 && ctx->pkt_ssid_len > 0 && ctx->pkt_ssid_len <= AIRPDCAP_WPA_SSID_MAX_LEN) {
1253 /* We have a "wildcard" SSID. Use the one from the packet. */
1254 memcpy(&pkt_key, tmp_key, sizeof(pkt_key));
1255 memcpy(&pkt_key.UserPwd.Ssid, ctx->pkt_ssid, ctx->pkt_ssid_len);
1256 pkt_key.UserPwd.SsidLen = ctx->pkt_ssid_len;
1257 AirPDcapRsnaPwd2Psk(pkt_key.UserPwd.Passphrase, pkt_key.UserPwd.Ssid,
1258 pkt_key.UserPwd.SsidLen, pkt_key.KeyData.Wpa.Psk);
1262 /* derive the PTK from the BSSID, STA MAC, PMK, SNonce, ANonce */
1263 AirPDcapRsnaPrfX(sa, /* authenticator nonce, bssid, station mac */
1264 tmp_key->KeyData.Wpa.Pmk, /* PMK */
1265 data+offset+12, /* supplicant nonce */
1269 /* verify the MIC (compare the MIC in the packet included in this message with a MIC calculated with the PTK) */
1270 eapol_len=pntohs(data+offset-3)+4;
1271 memcpy(eapol, &data[offset-5], (eapol_len<AIRPDCAP_EAPOL_MAX_LEN?eapol_len:AIRPDCAP_EAPOL_MAX_LEN));
1272 ret_value=AirPDcapRsnaMicCheck(eapol, /* eapol frame (header also) */
1273 eapol_len, /* eapol frame length */
1274 sa->wpa.ptk, /* Key Confirmation Key */
1275 AIRPDCAP_EAP_KEY_DESCR_VER(data[offset+1])); /* EAPOL-Key description version */
1277 /* If the MIC is valid, the Authenticator checks that the RSN information element bit-wise matches */
1278 /* that from the (Re)Association Request message. */
1279 /* i) TODO If these are not exactly the same, the Authenticator uses MLME-DEAUTHENTICATE.request */
1280 /* primitive to terminate the association. */
1281 /* ii) If they do match bit-wise, the Authenticator constructs Message 3. */
1285 (tmp_key->KeyType==AIRPDCAP_KEY_TYPE_WPA_PWD ||
1286 tmp_key->KeyType==AIRPDCAP_KEY_TYPE_WPA_PSK ||
1287 tmp_key->KeyType==AIRPDCAP_KEY_TYPE_WPA_PMK))
1289 /* the temporary key is the correct one, cached in the Security Association */
1294 memcpy(key, &tmp_key, sizeof(AIRPDCAP_KEY_ITEM));
1295 if (AIRPDCAP_EAP_KEY_DESCR_VER(data[offset+1])==AIRPDCAP_WPA_KEY_VER_NOT_CCMP)
1296 key->KeyType=AIRPDCAP_KEY_TYPE_TKIP;
1297 else if (AIRPDCAP_EAP_KEY_DESCR_VER(data[offset+1])==AIRPDCAP_WPA_KEY_VER_AES_CCMP)
1298 key->KeyType=AIRPDCAP_KEY_TYPE_CCMP;
1303 /* the cached key was not valid, try other keys */
1305 if (useCache==TRUE) {
1313 AIRPDCAP_DEBUG_PRINT_LINE("AirPDcapRsna4WHandshake", "handshake step failed", AIRPDCAP_DEBUG_LEVEL_3);
1314 return AIRPDCAP_RET_NO_VALID_HANDSHAKE;
1319 return AIRPDCAP_RET_SUCCESS_HANDSHAKE;
1323 /* TODO "Note that when the 4-Way Handshake is first used Message 4 is sent in the clear." */
1325 /* TODO check MIC and Replay Counter */
1326 /* On reception of Message 4, the Authenticator verifies that the Key Replay Counter field value is one */
1327 /* that it used on this 4-Way Handshake; if it is not, it silently discards the message. */
1328 /* If the calculated MIC does not match the MIC that the Supplicant included in the EAPOL-Key frame, the */
1329 /* Authenticator silently discards Message 4. */
1331 AIRPDCAP_DEBUG_PRINT_LINE("AirPDcapRsna4WHandshake", "4-way handshake message 4 (patched)", AIRPDCAP_DEBUG_LEVEL_3);
1337 return AIRPDCAP_RET_SUCCESS_HANDSHAKE;
1344 /* TODO "Note that when the 4-Way Handshake is first used Message 4 is sent in the clear." */
1346 /* TODO check MIC and Replay Counter */
1347 /* On reception of Message 4, the Authenticator verifies that the Key Replay Counter field value is one */
1348 /* that it used on this 4-Way Handshake; if it is not, it silently discards the message. */
1349 /* If the calculated MIC does not match the MIC that the Supplicant included in the EAPOL-Key frame, the */
1350 /* Authenticator silently discards Message 4. */
1352 AIRPDCAP_DEBUG_PRINT_LINE("AirPDcapRsna4WHandshake", "4-way handshake message 4", AIRPDCAP_DEBUG_LEVEL_3);
1358 return AIRPDCAP_RET_SUCCESS_HANDSHAKE;
1362 /* message 3: Authenticator->Supplicant (Sec=1, Mic=1, Ack=1, Inst=0/1, Key=1(pairwise), KeyRSC=???, Nonce=ANonce, MIC=1) */
1363 if (AIRPDCAP_EAP_ACK(data[offset+1])==1 &&
1364 AIRPDCAP_EAP_MIC(data[offset])==1)
1366 P_EAPOL_RSN_KEY pEAPKey;
1367 AIRPDCAP_DEBUG_PRINT_LINE("AirPDcapRsna4WHandshake", "4-way handshake message 3", AIRPDCAP_DEBUG_LEVEL_3);
1369 /* On reception of Message 3, the Supplicant silently discards the message if the Key Replay Counter field */
1370 /* value has already been used or if the ANonce value in Message 3 differs from the ANonce value in Message 1. */
1371 /* -> not checked, the Authenticator will send another message 3 (hopefully!) */
1373 /* TODO check page 88 (RNS) */
1375 /* If using WPA2 PSK, message 3 will contain an RSN for the group key (GTK KDE).
1376 In order to properly support decrypting WPA2-PSK packets, we need to parse this to get the group key.*/
1377 pEAPKey = (P_EAPOL_RSN_KEY)(&(data[offset-1]));
1378 if (pEAPKey->type == AIRPDCAP_RSN_WPA2_KEY_DESCRIPTOR){
1379 PAIRPDCAP_SEC_ASSOCIATION broadcast_sa;
1380 AIRPDCAP_SEC_ASSOCIATION_ID id;
1382 /* Get broadcacst SA for the current BSSID */
1383 memcpy(id.sta, broadcast_mac, AIRPDCAP_MAC_LEN);
1384 memcpy(id.bssid, sa->saId.bssid, AIRPDCAP_MAC_LEN);
1385 broadcast_sa = AirPDcapGetSaPtr(ctx, &id);
1387 if (broadcast_sa == NULL){
1388 return AIRPDCAP_RET_UNSUCCESS;
1390 AirPDcapDecryptWPABroadcastKey(pEAPKey, sa->wpa.ptk+16, broadcast_sa);
1393 return AIRPDCAP_RET_SUCCESS_HANDSHAKE;
1396 return AIRPDCAP_RET_UNSUCCESS;
1400 AirPDcapRsnaMicCheck(
1403 UCHAR KCK[AIRPDCAP_WPA_KCK_LEN],
1406 UCHAR mic[AIRPDCAP_WPA_MICKEY_LEN];
1407 UCHAR c_mic[20]; /* MIC 16 byte, the HMAC-SHA1 use a buffer of 20 bytes */
1409 /* copy the MIC from the EAPOL packet */
1410 memcpy(mic, eapol+AIRPDCAP_WPA_MICKEY_OFFSET+4, AIRPDCAP_WPA_MICKEY_LEN);
1412 /* set to 0 the MIC in the EAPOL packet (to calculate the MIC) */
1413 memset(eapol+AIRPDCAP_WPA_MICKEY_OFFSET+4, 0, AIRPDCAP_WPA_MICKEY_LEN);
1415 if (key_ver==AIRPDCAP_WPA_KEY_VER_NOT_CCMP) {
1416 /* use HMAC-MD5 for the EAPOL-Key MIC */
1417 md5_hmac(eapol, eapol_len, KCK, AIRPDCAP_WPA_KCK_LEN, c_mic);
1418 } else if (key_ver==AIRPDCAP_WPA_KEY_VER_AES_CCMP) {
1419 /* use HMAC-SHA1-128 for the EAPOL-Key MIC */
1420 sha1_hmac(KCK, AIRPDCAP_WPA_KCK_LEN, eapol, eapol_len, c_mic);
1422 /* key descriptor version not recognized */
1423 return AIRPDCAP_RET_UNSUCCESS;
1425 /* compare calculated MIC with the Key MIC and return result (0 means success) */
1426 return memcmp(mic, c_mic, AIRPDCAP_WPA_MICKEY_LEN);
1430 AirPDcapValidateKey(
1431 PAIRPDCAP_KEY_ITEM key)
1435 AIRPDCAP_DEBUG_TRACE_START("AirPDcapValidateKey");
1438 AIRPDCAP_DEBUG_PRINT_LINE("AirPDcapValidateKey", "NULL key", AIRPDCAP_DEBUG_LEVEL_5);
1439 AIRPDCAP_DEBUG_TRACE_START("AirPDcapValidateKey");
1443 switch (key->KeyType) {
1444 case AIRPDCAP_KEY_TYPE_WEP:
1445 /* check key size limits */
1446 len=key->KeyData.Wep.WepKeyLen;
1447 if (len<AIRPDCAP_WEP_KEY_MINLEN || len>AIRPDCAP_WEP_KEY_MAXLEN) {
1448 AIRPDCAP_DEBUG_PRINT_LINE("AirPDcapValidateKey", "WEP key: key length not accepted", AIRPDCAP_DEBUG_LEVEL_5);
1453 case AIRPDCAP_KEY_TYPE_WEP_40:
1454 /* set the standard length and use a generic WEP key type */
1455 key->KeyData.Wep.WepKeyLen=AIRPDCAP_WEP_40_KEY_LEN;
1456 key->KeyType=AIRPDCAP_KEY_TYPE_WEP;
1459 case AIRPDCAP_KEY_TYPE_WEP_104:
1460 /* set the standard length and use a generic WEP key type */
1461 key->KeyData.Wep.WepKeyLen=AIRPDCAP_WEP_104_KEY_LEN;
1462 key->KeyType=AIRPDCAP_KEY_TYPE_WEP;
1465 case AIRPDCAP_KEY_TYPE_WPA_PWD:
1466 /* check passphrase and SSID size limits */
1467 len=strlen(key->UserPwd.Passphrase);
1468 if (len<AIRPDCAP_WPA_PASSPHRASE_MIN_LEN || len>AIRPDCAP_WPA_PASSPHRASE_MAX_LEN) {
1469 AIRPDCAP_DEBUG_PRINT_LINE("AirPDcapValidateKey", "WPA-PWD key: passphrase length not accepted", AIRPDCAP_DEBUG_LEVEL_5);
1473 len=key->UserPwd.SsidLen;
1474 if (len>AIRPDCAP_WPA_SSID_MAX_LEN) {
1475 AIRPDCAP_DEBUG_PRINT_LINE("AirPDcapValidateKey", "WPA-PWD key: ssid length not accepted", AIRPDCAP_DEBUG_LEVEL_5);
1481 case AIRPDCAP_KEY_TYPE_WPA_PSK:
1484 case AIRPDCAP_KEY_TYPE_WPA_PMK:
1491 AIRPDCAP_DEBUG_TRACE_END("AirPDcapValidateKey");
1497 PAIRPDCAP_CONTEXT ctx,
1498 AIRPDCAP_SEC_ASSOCIATION_ID *id)
1502 if (ctx->sa_index!=-1) {
1503 /* at least one association was stored */
1504 /* search for the association from sa_index to 0 (most recent added) */
1505 for (sa_index=ctx->sa_index; sa_index>=0; sa_index--) {
1506 if (ctx->sa[sa_index].used) {
1507 if (memcmp(id, &(ctx->sa[sa_index].saId), sizeof(AIRPDCAP_SEC_ASSOCIATION_ID))==0) {
1508 ctx->index=sa_index;
1520 PAIRPDCAP_CONTEXT ctx,
1521 AIRPDCAP_SEC_ASSOCIATION_ID *id)
1525 if (ctx->sa[ctx->first_free_index].used) {
1526 /* last addition was in the middle of the array (and the first_free_index was just incremented by 1) */
1527 /* search for a free space from the first_free_index to AIRPDCAP_STA_INFOS_NR (to avoid free blocks in */
1529 for (last_free=ctx->first_free_index; last_free<AIRPDCAP_MAX_SEC_ASSOCIATIONS_NR; last_free++)
1530 if (!ctx->sa[last_free].used)
1533 if (last_free>=AIRPDCAP_MAX_SEC_ASSOCIATIONS_NR) {
1534 /* there is no empty space available. FAILURE */
1538 /* store first free space index */
1539 ctx->first_free_index=last_free;
1543 ctx->index=ctx->first_free_index;
1545 /* reset the info structure */
1546 memset(ctx->sa+ctx->index, 0, sizeof(AIRPDCAP_SEC_ASSOCIATION));
1548 ctx->sa[ctx->index].used=1;
1550 /* set the info structure */
1551 memcpy(&(ctx->sa[ctx->index].saId), id, sizeof(AIRPDCAP_SEC_ASSOCIATION_ID));
1553 /* increment by 1 the first_free_index (heuristic) */
1554 ctx->first_free_index++;
1556 /* set the sa_index if the added index is greater the the sa_index */
1557 if (ctx->index > ctx->sa_index)
1558 ctx->sa_index=ctx->index;
1564 * AirPDcapGetBssidAddress() and AirPDcapGetBssidAddress() are used for
1565 * key caching. In each case, it's more important to return a value than
1566 * to return a _correct_ value, so we fudge addresses in some cases, e.g.
1567 * the BSSID in bridged connections.
1568 * FromDS ToDS Sta BSSID
1575 static const UCHAR *
1576 AirPDcapGetStaAddress(
1577 const AIRPDCAP_MAC_FRAME_ADDR4 *frame)
1579 switch(AIRPDCAP_DS_BITS(frame->fc[1])) { /* Bit 1 = FromDS, bit 0 = ToDS */
1583 return frame->addr2;
1585 return frame->addr1;
1591 static const UCHAR *
1592 AirPDcapGetBssidAddress(
1593 const AIRPDCAP_MAC_FRAME_ADDR4 *frame)
1595 switch(AIRPDCAP_DS_BITS(frame->fc[1])) { /* Bit 1 = FromDS, bit 0 = ToDS */
1597 return frame->addr3;
1600 return frame->addr1;
1602 return frame->addr2;
1608 /* Function used to derive the PTK. Refer to IEEE 802.11I-2004, pag. 74 */
1611 AIRPDCAP_SEC_ASSOCIATION *sa,
1612 const UCHAR pmk[32],
1613 const UCHAR snonce[32],
1614 const INT x, /* for TKIP 512, for CCMP 384 */
1619 INT offset=sizeof("Pairwise key expansion");
1623 memcpy(R, "Pairwise key expansion", offset);
1625 /* Min(AA, SPA) || Max(AA, SPA) */
1626 if (memcmp(sa->saId.sta, sa->saId.bssid, AIRPDCAP_MAC_LEN) < 0)
1628 memcpy(R + offset, sa->saId.sta, AIRPDCAP_MAC_LEN);
1629 memcpy(R + offset+AIRPDCAP_MAC_LEN, sa->saId.bssid, AIRPDCAP_MAC_LEN);
1633 memcpy(R + offset, sa->saId.bssid, AIRPDCAP_MAC_LEN);
1634 memcpy(R + offset+AIRPDCAP_MAC_LEN, sa->saId.sta, AIRPDCAP_MAC_LEN);
1637 offset+=AIRPDCAP_MAC_LEN*2;
1639 /* Min(ANonce,SNonce) || Max(ANonce,SNonce) */
1640 if( memcmp(snonce, sa->wpa.nonce, 32) < 0 )
1642 memcpy(R + offset, snonce, 32);
1643 memcpy(R + offset + 32, sa->wpa.nonce, 32);
1647 memcpy(R + offset, sa->wpa.nonce, 32);
1648 memcpy(R + offset + 32, snonce, 32);
1653 for(i = 0; i < (x+159)/160; i++)
1656 sha1_hmac(pmk, 32, R, 100, ptk + i * 20);
1661 AirPDcapRsnaPwd2PskStep(
1662 const guint8 *ppBytes,
1663 const guint ppLength,
1665 const size_t ssidLength,
1666 const INT iterations,
1670 UCHAR digest[36], digest1[AIRPDCAP_SHA_DIGEST_LEN];
1673 /* U1 = PRF(P, S || INT(i)) */
1674 memcpy(digest, ssid, ssidLength);
1675 digest[ssidLength] = (UCHAR)((count>>24) & 0xff);
1676 digest[ssidLength+1] = (UCHAR)((count>>16) & 0xff);
1677 digest[ssidLength+2] = (UCHAR)((count>>8) & 0xff);
1678 digest[ssidLength+3] = (UCHAR)(count & 0xff);
1679 sha1_hmac(ppBytes, ppLength, digest, ssidLength+4, digest1);
1682 memcpy(output, digest1, AIRPDCAP_SHA_DIGEST_LEN);
1683 for (i = 1; i < iterations; i++) {
1684 /* Un = PRF(P, Un-1) */
1685 sha1_hmac(ppBytes, ppLength, digest1, AIRPDCAP_SHA_DIGEST_LEN, digest);
1687 memcpy(digest1, digest, AIRPDCAP_SHA_DIGEST_LEN);
1688 /* output = output xor Un */
1689 for (j = 0; j < AIRPDCAP_SHA_DIGEST_LEN; j++) {
1690 output[j] ^= digest[j];
1694 return AIRPDCAP_RET_SUCCESS;
1698 AirPDcapRsnaPwd2Psk(
1699 const CHAR *passphrase,
1701 const size_t ssidLength,
1704 UCHAR m_output[AIRPDCAP_WPA_PSK_LEN];
1705 GByteArray *pp_ba = g_byte_array_new();
1707 memset(m_output, 0, AIRPDCAP_WPA_PSK_LEN);
1709 if (!uri_str_to_bytes(passphrase, pp_ba)) {
1710 g_byte_array_free(pp_ba, TRUE);
1714 AirPDcapRsnaPwd2PskStep(pp_ba->data, pp_ba->len, ssid, ssidLength, 4096, 1, m_output);
1715 AirPDcapRsnaPwd2PskStep(pp_ba->data, pp_ba->len, ssid, ssidLength, 4096, 2, &m_output[AIRPDCAP_SHA_DIGEST_LEN]);
1717 memcpy(output, m_output, AIRPDCAP_WPA_PSK_LEN);
1718 g_byte_array_free(pp_ba, TRUE);
1724 * Returns the decryption_key_t struct given a string describing the key.
1725 * Returns NULL if the key_string cannot be parsed.
1728 parse_key_string(gchar* input_string)
1734 GString *key_string = NULL;
1735 GByteArray *ssid_ba = NULL, *key_ba;
1740 decryption_key_t *dk;
1741 gchar *first_nibble = input_string;
1743 if(input_string == NULL)
1747 * Parse the input_string. It should be in the form
1748 * <key type>:<key data>[:<ssid>]
1749 * XXX - For backward compatibility, the a WEP key can be just a string
1750 * of hexadecimal characters (if WEP key is wrong, null will be
1754 /* First, check for a WEP string */
1755 /* XXX - This duplicates code in packet-ieee80211.c */
1756 if (g_ascii_strncasecmp(input_string, STRING_KEY_TYPE_WEP ":", 4) == 0) {
1760 key_ba = g_byte_array_new();
1761 res = hex_str_to_bytes(first_nibble, key_ba, FALSE);
1763 if (res && key_ba->len > 0) {
1764 /* Key is correct! It was probably an 'old style' WEP key */
1765 /* Create the decryption_key_t structure, fill it and return it*/
1766 dk = g_malloc(sizeof(decryption_key_t));
1768 dk->type = AIRPDCAP_KEY_TYPE_WEP;
1769 /* XXX - The current key handling code in the GUI requires
1770 * no separators and lower case */
1771 dk->key = g_string_new(bytes_to_str(key_ba->data, key_ba->len));
1772 g_string_down(dk->key);
1773 dk->bits = key_ba->len * 8;
1776 g_byte_array_free(key_ba, TRUE);
1779 g_byte_array_free(key_ba, TRUE);
1782 tokens = g_strsplit(input_string,":",0);
1784 /* Tokens is a null termiated array of strings ... */
1785 while(tokens[n] != NULL)
1790 /* Free the array of strings */
1795 type = g_strdup(tokens[0]);
1798 * The second token is the key (right now it doesn't matter
1799 * if it is a passphrase[+ssid] or an hexadecimal one)
1801 key = g_strdup(tokens[1]);
1804 /* Maybe there is a third token (an ssid, if everything else is ok) */
1807 ssid = g_strdup(tokens[2]);
1810 if (g_ascii_strcasecmp(type,STRING_KEY_TYPE_WPA_PSK) == 0) /* WPA key */
1812 /* Create a new string */
1813 key_string = g_string_new(key);
1815 key_ba = g_byte_array_new();
1816 res = hex_str_to_bytes(key, key_ba, FALSE);
1818 /* Two tokens means that the user should have entered a WPA-BIN key ... */
1819 if(!res || ((key_string->len) != WPA_PSK_KEY_CHAR_SIZE))
1821 g_string_free(key_string, TRUE);
1822 g_byte_array_free(key_ba, TRUE);
1826 /* No ssid has been created ... */
1827 /* Free the array of strings */
1832 /* Key was correct!!! Create the new decryption_key_t ... */
1833 dk = (decryption_key_t*)g_malloc(sizeof(decryption_key_t));
1835 dk->type = AIRPDCAP_KEY_TYPE_WPA_PMK;
1836 dk->key = g_string_new(key);
1837 dk->bits = dk->key->len * 4;
1840 g_string_free(key_string, TRUE);
1841 g_byte_array_free(key_ba, TRUE);
1845 /* Free the array of strings */
1849 else if(g_ascii_strcasecmp(type,STRING_KEY_TYPE_WPA_PWD) == 0) /* WPA key *//* If the number of tokens is more than three, we accept the string... if the first three tokens are correct... */
1851 /* Create a new string */
1852 key_string = g_string_new(key);
1855 /* Three (or more) tokens mean that the user entered a WPA-PWD key ... */
1856 if( ((key_string->len) > WPA_KEY_MAX_CHAR_SIZE) || ((key_string->len) < WPA_KEY_MIN_CHAR_SIZE))
1858 g_string_free(key_string, TRUE);
1864 /* Free the array of strings */
1869 if(ssid != NULL) /* more than three tokens found, means that the user specified the ssid */
1871 ssid_ba = g_byte_array_new();
1872 if (! uri_str_to_bytes(ssid, ssid_ba)) {
1873 g_string_free(key_string, TRUE);
1874 g_byte_array_free(ssid_ba, TRUE);
1878 /* Free the array of strings */
1883 if(ssid_ba->len > WPA_SSID_MAX_CHAR_SIZE)
1885 g_string_free(key_string, TRUE);
1886 g_byte_array_free(ssid_ba, TRUE);
1892 /* Free the array of strings */
1898 /* Key was correct!!! Create the new decryption_key_t ... */
1899 dk = (decryption_key_t*)g_malloc(sizeof(decryption_key_t));
1901 dk->type = AIRPDCAP_KEY_TYPE_WPA_PWD;
1902 dk->key = g_string_new(key);
1903 dk->bits = 256; /* This is the length of the array pf bytes that will be generated using key+ssid ...*/
1904 dk->ssid = byte_array_dup(ssid_ba); /* NULL if ssid_ba is NULL */
1906 g_string_free(key_string, TRUE);
1907 if (ssid_ba != NULL)
1908 g_byte_array_free(ssid_ba, TRUE);
1915 /* Free the array of strings */
1920 /* Something was wrong ... free everything */
1925 g_free(ssid); /* It is not always present */
1926 if (ssid_ba != NULL)
1927 g_byte_array_free(ssid_ba, TRUE);
1929 /* Free the array of strings */
1936 * Returns a newly allocated string representing the given decryption_key_t
1937 * struct, or NULL if something is wrong...
1940 get_key_string(decryption_key_t* dk)
1942 gchar* output_string = NULL;
1944 if(dk == NULL || dk->key == NULL)
1948 case AIRPDCAP_KEY_TYPE_WEP:
1949 output_string = g_strdup_printf("%s:%s",STRING_KEY_TYPE_WEP,dk->key->str);
1951 case AIRPDCAP_KEY_TYPE_WPA_PWD:
1952 if(dk->ssid == NULL)
1953 output_string = g_strdup_printf("%s:%s",STRING_KEY_TYPE_WPA_PWD,dk->key->str);
1955 output_string = g_strdup_printf("%s:%s:%s",
1956 STRING_KEY_TYPE_WPA_PWD, dk->key->str,
1957 format_uri(dk->ssid, ":"));
1959 case AIRPDCAP_KEY_TYPE_WPA_PMK:
1960 output_string = g_strdup_printf("%s:%s",STRING_KEY_TYPE_WPA_PSK,dk->key->str);
1966 return output_string;
1973 /****************************************************************************/
1981 * indent-tabs-mode: nil
1984 * ex: set shiftwidth=4 tabstop=8 expandtab
1985 * :indentSize=4:tabSize=8:noTabs=true: