/* * 802.11 to Ethernet pcap translator * * Copyright (C) 2006,2007 Thomas d'Otreppe * Copyright (C) 2004,2005 Christophe Devine * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ #include #include #include #include #include #include #include "version.h" #include "crypto.h" #ifdef WIN32 #include #include #endif #include "pcap.h" #define CRYPT_NONE 0 #define CRYPT_WEP 1 #define CRYPT_WPA 2 #define IEEE80211_FC0_SUBTYPE_MASK 0xf0 #define IEEE80211_FC0_SUBTYPE_SHIFT 4 /* for TYPE_DATA (bit combination) */ #define IEEE80211_FC0_SUBTYPE_QOS 0x80 #define IEEE80211_FC0_SUBTYPE_QOS_NULL 0xc0 #define GET_SUBTYPE(fc) \ ( ( (fc) & IEEE80211_FC0_SUBTYPE_MASK ) >> IEEE80211_FC0_SUBTYPE_SHIFT ) \ << IEEE80211_FC0_SUBTYPE_SHIFT extern char * getVersion(char * progname, int maj, int min, int submin, int svnrev); extern int check_crc_buf( unsigned char *buf, int len ); extern int calc_crc_buf( unsigned char *buf, int len ); const short Sbox[2][256]= { { 0xC6A5, 0xF884, 0xEE99, 0xF68D, 0xFF0D, 0xD6BD, 0xDEB1, 0x9154, 0x6050, 0x0203, 0xCEA9, 0x567D, 0xE719, 0xB562, 0x4DE6, 0xEC9A, 0x8F45, 0x1F9D, 0x8940, 0xFA87, 0xEF15, 0xB2EB, 0x8EC9, 0xFB0B, 0x41EC, 0xB367, 0x5FFD, 0x45EA, 0x23BF, 0x53F7, 0xE496, 0x9B5B, 0x75C2, 0xE11C, 0x3DAE, 0x4C6A, 0x6C5A, 0x7E41, 0xF502, 0x834F, 0x685C, 0x51F4, 0xD134, 0xF908, 0xE293, 0xAB73, 0x6253, 0x2A3F, 0x080C, 0x9552, 0x4665, 0x9D5E, 0x3028, 0x37A1, 0x0A0F, 0x2FB5, 0x0E09, 0x2436, 0x1B9B, 0xDF3D, 0xCD26, 0x4E69, 0x7FCD, 0xEA9F, 0x121B, 0x1D9E, 0x5874, 0x342E, 0x362D, 0xDCB2, 0xB4EE, 0x5BFB, 0xA4F6, 0x764D, 0xB761, 0x7DCE, 0x527B, 0xDD3E, 0x5E71, 0x1397, 0xA6F5, 0xB968, 0x0000, 0xC12C, 0x4060, 0xE31F, 0x79C8, 0xB6ED, 0xD4BE, 0x8D46, 0x67D9, 0x724B, 0x94DE, 0x98D4, 0xB0E8, 0x854A, 0xBB6B, 0xC52A, 0x4FE5, 0xED16, 0x86C5, 0x9AD7, 0x6655, 0x1194, 0x8ACF, 0xE910, 0x0406, 0xFE81, 0xA0F0, 0x7844, 0x25BA, 0x4BE3, 0xA2F3, 0x5DFE, 0x80C0, 0x058A, 0x3FAD, 0x21BC, 0x7048, 0xF104, 0x63DF, 0x77C1, 0xAF75, 0x4263, 0x2030, 0xE51A, 0xFD0E, 0xBF6D, 0x814C, 0x1814, 0x2635, 0xC32F, 0xBEE1, 0x35A2, 0x88CC, 0x2E39, 0x9357, 0x55F2, 0xFC82, 0x7A47, 0xC8AC, 0xBAE7, 0x322B, 0xE695, 0xC0A0, 0x1998, 0x9ED1, 0xA37F, 0x4466, 0x547E, 0x3BAB, 0x0B83, 0x8CCA, 0xC729, 0x6BD3, 0x283C, 0xA779, 0xBCE2, 0x161D, 0xAD76, 0xDB3B, 0x6456, 0x744E, 0x141E, 0x92DB, 0x0C0A, 0x486C, 0xB8E4, 0x9F5D, 0xBD6E, 0x43EF, 0xC4A6, 0x39A8, 0x31A4, 0xD337, 0xF28B, 0xD532, 0x8B43, 0x6E59, 0xDAB7, 0x018C, 0xB164, 0x9CD2, 0x49E0, 0xD8B4, 0xACFA, 0xF307, 0xCF25, 0xCAAF, 0xF48E, 0x47E9, 0x1018, 0x6FD5, 0xF088, 0x4A6F, 0x5C72, 0x3824, 0x57F1, 0x73C7, 0x9751, 0xCB23, 0xA17C, 0xE89C, 0x3E21, 0x96DD, 0x61DC, 0x0D86, 0x0F85, 0xE090, 0x7C42, 0x71C4, 0xCCAA, 0x90D8, 0x0605, 0xF701, 0x1C12, 0xC2A3, 0x6A5F, 0xAEF9, 0x69D0, 0x1791, 0x9958, 0x3A27, 0x27B9, 0xD938, 0xEB13, 0x2BB3, 0x2233, 0xD2BB, 0xA970, 0x0789, 0x33A7, 0x2DB6, 0x3C22, 0x1592, 0xC920, 0x8749, 0xAAFF, 0x5078, 0xA57A, 0x038F, 0x59F8, 0x0980, 0x1A17, 0x65DA, 0xD731, 0x84C6, 0xD0B8, 0x82C3, 0x29B0, 0x5A77, 0x1E11, 0x7BCB, 0xA8FC, 0x6DD6, 0x2C3A }, { 0xA5C6, 0x84F8, 0x99EE, 0x8DF6, 0x0DFF, 0xBDD6, 0xB1DE, 0x5491, 0x5060, 0x0302, 0xA9CE, 0x7D56, 0x19E7, 0x62B5, 0xE64D, 0x9AEC, 0x458F, 0x9D1F, 0x4089, 0x87FA, 0x15EF, 0xEBB2, 0xC98E, 0x0BFB, 0xEC41, 0x67B3, 0xFD5F, 0xEA45, 0xBF23, 0xF753, 0x96E4, 0x5B9B, 0xC275, 0x1CE1, 0xAE3D, 0x6A4C, 0x5A6C, 0x417E, 0x02F5, 0x4F83, 0x5C68, 0xF451, 0x34D1, 0x08F9, 0x93E2, 0x73AB, 0x5362, 0x3F2A, 0x0C08, 0x5295, 0x6546, 0x5E9D, 0x2830, 0xA137, 0x0F0A, 0xB52F, 0x090E, 0x3624, 0x9B1B, 0x3DDF, 0x26CD, 0x694E, 0xCD7F, 0x9FEA, 0x1B12, 0x9E1D, 0x7458, 0x2E34, 0x2D36, 0xB2DC, 0xEEB4, 0xFB5B, 0xF6A4, 0x4D76, 0x61B7, 0xCE7D, 0x7B52, 0x3EDD, 0x715E, 0x9713, 0xF5A6, 0x68B9, 0x0000, 0x2CC1, 0x6040, 0x1FE3, 0xC879, 0xEDB6, 0xBED4, 0x468D, 0xD967, 0x4B72, 0xDE94, 0xD498, 0xE8B0, 0x4A85, 0x6BBB, 0x2AC5, 0xE54F, 0x16ED, 0xC586, 0xD79A, 0x5566, 0x9411, 0xCF8A, 0x10E9, 0x0604, 0x81FE, 0xF0A0, 0x4478, 0xBA25, 0xE34B, 0xF3A2, 0xFE5D, 0xC080, 0x8A05, 0xAD3F, 0xBC21, 0x4870, 0x04F1, 0xDF63, 0xC177, 0x75AF, 0x6342, 0x3020, 0x1AE5, 0x0EFD, 0x6DBF, 0x4C81, 0x1418, 0x3526, 0x2FC3, 0xE1BE, 0xA235, 0xCC88, 0x392E, 0x5793, 0xF255, 0x82FC, 0x477A, 0xACC8, 0xE7BA, 0x2B32, 0x95E6, 0xA0C0, 0x9819, 0xD19E, 0x7FA3, 0x6644, 0x7E54, 0xAB3B, 0x830B, 0xCA8C, 0x29C7, 0xD36B, 0x3C28, 0x79A7, 0xE2BC, 0x1D16, 0x76AD, 0x3BDB, 0x5664, 0x4E74, 0x1E14, 0xDB92, 0x0A0C, 0x6C48, 0xE4B8, 0x5D9F, 0x6EBD, 0xEF43, 0xA6C4, 0xA839, 0xA431, 0x37D3, 0x8BF2, 0x32D5, 0x438B, 0x596E, 0xB7DA, 0x8C01, 0x64B1, 0xD29C, 0xE049, 0xB4D8, 0xFAAC, 0x07F3, 0x25CF, 0xAFCA, 0x8EF4, 0xE947, 0x1810, 0xD56F, 0x88F0, 0x6F4A, 0x725C, 0x2438, 0xF157, 0xC773, 0x5197, 0x23CB, 0x7CA1, 0x9CE8, 0x213E, 0xDD96, 0xDC61, 0x860D, 0x850F, 0x90E0, 0x427C, 0xC471, 0xAACC, 0xD890, 0x0506, 0x01F7, 0x121C, 0xA3C2, 0x5F6A, 0xF9AE, 0xD069, 0x9117, 0x5899, 0x273A, 0xB927, 0x38D9, 0x13EB, 0xB32B, 0x3322, 0xBBD2, 0x70A9, 0x8907, 0xA733, 0xB62D, 0x223C, 0x9215, 0x20C9, 0x4987, 0xFFAA, 0x7850, 0x7AA5, 0x8F03, 0xF859, 0x8009, 0x171A, 0xDA65, 0x31D7, 0xC684, 0xB8D0, 0xC382, 0xB029, 0x775A, 0x111E, 0xCB7B, 0xFCA8, 0xD66D, 0x3A2C } }; char usage[] = "\n" " %s - (C) 2006,2007 Thomas d\'Otreppe\n" " Original work: Christophe Devine\n" " http://www.aircrack-ng.org\n" "\n" " usage: airdecap-ng [options] \n" "\n" " Common options:\n" " -l : don't remove the 802.11 header\n" " -b : access point MAC address filter\n" " -e : target network SSID\n" "\n" " WEP specific option:\n" " -w : target network WEP key in hex\n" "\n" " WPA specific options:\n" " -p : target network WPA passphrase\n" " -k : WPA Pairwise Master Key in hex\n" "\n" " --help : Displays this usage screen\n" "\n"; /* derive the PMK from the passphrase and the essid */ void calc_pmk( char *key, char *essid_pre, uchar pmk[40] ) { int i, j, slen; uchar buffer[65]; uchar essid[33+4]; sha1_context ctx_ipad; sha1_context ctx_opad; sha1_context sha1_ctx; memset(essid,0,sizeof(essid)); memcpy(essid,essid_pre,strlen(essid_pre)); slen = (int)strlen((char*)essid)+4; /* setup the inner and outer contexts */ memset( buffer, 0, sizeof( buffer ) ); strncpy( (char *) buffer, key, sizeof( buffer ) - 1 ); for( i = 0; i < 64; i++ ) buffer[i] ^= 0x36; sha1_starts( &ctx_ipad ); sha1_update( &ctx_ipad, buffer, 64 ); for( i = 0; i < 64; i++ ) buffer[i] ^= 0x6A; sha1_starts( &ctx_opad ); sha1_update( &ctx_opad, buffer, 64 ); /* iterate HMAC-SHA1 over itself 8192 times */ essid[slen - 1] = '\1'; hmac_sha1( (uchar *) key, strlen( key ), (uchar *) essid, slen, pmk ); memcpy( buffer, pmk, 20 ); for( i = 1; i < 4096; i++ ) { memcpy( &sha1_ctx, &ctx_ipad, sizeof( sha1_ctx ) ); sha1_update( &sha1_ctx, buffer, 20 ); sha1_finish( &sha1_ctx, buffer ); memcpy( &sha1_ctx, &ctx_opad, sizeof( sha1_ctx ) ); sha1_update( &sha1_ctx, buffer, 20 ); sha1_finish( &sha1_ctx, buffer ); for( j = 0; j < 20; j++ ) pmk[j] ^= buffer[j]; } essid[slen - 1] = '\2'; hmac_sha1( (uchar *) key, strlen( key ), (uchar *) essid, slen, pmk + 20 ); memcpy( buffer, pmk + 20, 20 ); for( i = 1; i < 4096; i++ ) { memcpy( &sha1_ctx, &ctx_ipad, sizeof( sha1_ctx ) ); sha1_update( &sha1_ctx, buffer, 20 ); sha1_finish( &sha1_ctx, buffer ); memcpy( &sha1_ctx, &ctx_opad, sizeof( sha1_ctx ) ); sha1_update( &sha1_ctx, buffer, 20 ); sha1_finish( &sha1_ctx, buffer ); for( j = 0; j < 20; j++ ) pmk[j + 20] ^= buffer[j]; } } struct ST_info { struct ST_info *next; /* next supplicant */ uchar stmac[6]; /* supplicant MAC */ uchar bssid[6]; /* authenticator MAC */ uchar snonce[32]; /* supplicant nonce */ uchar anonce[32]; /* authenticator nonce */ uchar keymic[20]; /* eapol frame MIC */ uchar eapol[256]; /* eapol frame contents */ uchar ptk[80]; /* pairwise transcient key */ int eapol_size; /* eapol frame size */ unsigned long t_crc; /* last ToDS frame CRC */ unsigned long f_crc; /* last FromDS frame CRC */ int keyver, valid_ptk; }; /* derive the pairwise transcient keys from a bunch of stuff */ int calc_ptk( struct ST_info *wpa, uchar pmk[32] ) { int i; uchar pke[100]; uchar mic[20]; memcpy( pke, "Pairwise key expansion", 23 ); if( memcmp( wpa->stmac, wpa->bssid, 6 ) < 0 ) { memcpy( pke + 23, wpa->stmac, 6 ); memcpy( pke + 29, wpa->bssid, 6 ); } else { memcpy( pke + 23, wpa->bssid, 6 ); memcpy( pke + 29, wpa->stmac, 6 ); } if( memcmp( wpa->snonce, wpa->anonce, 32 ) < 0 ) { memcpy( pke + 35, wpa->snonce, 32 ); memcpy( pke + 67, wpa->anonce, 32 ); } else { memcpy( pke + 35, wpa->anonce, 32 ); memcpy( pke + 67, wpa->snonce, 32 ); } for( i = 0; i < 4; i++ ) { pke[99] = i; hmac_sha1( pmk, 32, pke, 100, wpa->ptk + i * 20 ); } /* check the EAPOL frame MIC */ if( ( wpa->keyver & 0x07 ) == 1 ) hmac_md5( wpa->ptk, 16, wpa->eapol, wpa->eapol_size, mic ); else hmac_sha1( wpa->ptk, 16, wpa->eapol, wpa->eapol_size, mic ); return( memcmp( mic, wpa->keymic, 16 ) == 0 ); } /* WEP (barebone RC4) decryption routine */ int decrypt_wep( uchar *data, int len, uchar *key, int keylen ) { struct rc4_state S; rc4_setup( &S, key, keylen ); rc4_crypt( &S, data, len ); return( check_crc_buf( data, len - 4 ) ); } /* TKIP (RC4 + key mixing) decryption routine */ #define ROTR1(x) ((((x) >> 1) & 0x7FFF) ^ (((x) & 1) << 15)) #define LO8(x) ( (x) & 0x00FF ) #define LO16(x) ( (x) & 0xFFFF ) #define HI8(x) ( ((x) >> 8) & 0x00FF ) #define HI16(x) ( ((x) >> 16) & 0xFFFF ) #define MK16(hi,lo) ( (lo) ^ ( LO8(hi) << 8 ) ) #define TK16(N) MK16(TK1[2*(N)+1],TK1[2*(N)]) #define _S_(x) (Sbox[0][LO8(x)] ^ Sbox[1][HI8(x)]) int decrypt_tkip( uchar *h80211, int caplen, uchar TK1[16] ) { int i, z; uint IV32; ushort IV16; ushort PPK[6]; uchar K[16]; z = ( ( h80211[1] & 3 ) != 3 ) ? 24 : 30; if ( GET_SUBTYPE(h80211[0]) == IEEE80211_FC0_SUBTYPE_QOS ) { z += 2; } IV16 = MK16( h80211[z], h80211[z + 2] ); IV32 = ( h80211[z + 4] ) | ( h80211[z + 5] << 8 ) | ( h80211[z + 6] << 16 ) | ( h80211[z + 7] << 24 ); PPK[0] = LO16( IV32 ); PPK[1] = HI16( IV32 ); PPK[2] = MK16( h80211[11], h80211[10] ); PPK[3] = MK16( h80211[13], h80211[12] ); PPK[4] = MK16( h80211[15], h80211[14] ); for( i = 0; i < 8; i++ ) { PPK[0] += _S_( PPK[4] ^ TK16( (i & 1) + 0 ) ); PPK[1] += _S_( PPK[0] ^ TK16( (i & 1) + 2 ) ); PPK[2] += _S_( PPK[1] ^ TK16( (i & 1) + 4 ) ); PPK[3] += _S_( PPK[2] ^ TK16( (i & 1) + 6 ) ); PPK[4] += _S_( PPK[3] ^ TK16( (i & 1) + 0 ) ) + i; } PPK[5] = PPK[4] + IV16; PPK[0] += _S_( PPK[5] ^ TK16(0) ); PPK[1] += _S_( PPK[0] ^ TK16(1) ); PPK[2] += _S_( PPK[1] ^ TK16(2) ); PPK[3] += _S_( PPK[2] ^ TK16(3) ); PPK[4] += _S_( PPK[3] ^ TK16(4) ); PPK[5] += _S_( PPK[4] ^ TK16(5) ); PPK[0] += ROTR1( PPK[5] ^ TK16(6) ); PPK[1] += ROTR1( PPK[0] ^ TK16(7) ); PPK[2] += ROTR1( PPK[1] ); PPK[3] += ROTR1( PPK[2] ); PPK[4] += ROTR1( PPK[3] ); PPK[5] += ROTR1( PPK[4] ); K[0] = HI8( IV16 ); K[1] = ( HI8( IV16 ) | 0x20 ) & 0x7F; K[2] = LO8( IV16 ); K[3] = LO8( (PPK[5] ^ TK16(0) ) >> 1); for( i = 0; i < 6; i++ ) { K[4 + ( 2 * i)] = LO8( PPK[i] ); K[5 + ( 2 * i)] = HI8( PPK[i] ); } return( decrypt_wep( h80211 + z + 8, caplen - z - 8, K, 16 ) ); } /* CCMP (AES-CTR-MAC) decryption routine */ static inline void XOR( uchar *dst, uchar *src, int len ) { int i; for( i = 0; i < len; i++ ) dst[i] ^= src[i]; } int decrypt_ccmp( uchar *h80211, int caplen, uchar TK1[16] ) { int is_a4, i, n, z, blocks; int data_len, last, offset; uchar B0[16], B[16], MIC[16]; uchar PN[6], AAD[32]; aes_context aes_ctx; is_a4 = ( h80211[1] & 3 ) == 3; z = 24 + 6 * is_a4; PN[0] = h80211[z + 7]; PN[1] = h80211[z + 6]; PN[2] = h80211[z + 5]; PN[3] = h80211[z + 4]; PN[4] = h80211[z + 1]; PN[5] = h80211[z + 0]; data_len = caplen - z - 8 - 8; B0[0] = 0x59; B0[1] = 0; memcpy( B0 + 2, h80211 + 10, 6 ); memcpy( B0 + 8, PN, 6 ); B0[14] = ( data_len >> 8 ) & 0xFF; B0[15] = ( data_len & 0xFF ); memset( AAD, 0, sizeof( AAD ) ); AAD[1] = 22 + 6 * is_a4; AAD[2] = h80211[0] & 0x8F; AAD[3] = h80211[1] & 0xC7; memcpy( AAD + 4, h80211 + 4, 3 * 6 ); AAD[22] = h80211[22] & 0x0F; if( is_a4 ) memcpy( AAD + 24, h80211 + 24, 6 ); aes_set_key( &aes_ctx, TK1, 128 ); aes_encrypt( &aes_ctx, B0, MIC ); XOR( MIC, AAD, 16 ); aes_encrypt( &aes_ctx, MIC, MIC ); XOR( MIC, AAD + 16, 16 ); aes_encrypt( &aes_ctx, MIC, MIC ); B0[0] &= 0x07; B0[14] = B0[15] = 0; aes_encrypt( &aes_ctx, B0, B ); XOR( h80211 + caplen - 8, B, 8 ); blocks = ( data_len + 16 - 1 ) / 16; last = data_len % 16; offset = z + 8; for( i = 1; i <= blocks; i++ ) { n = ( last > 0 && i == blocks ) ? last : 16; B0[14] = ( i >> 8 ) & 0xFF; B0[15] = i & 0xFF; aes_encrypt( &aes_ctx, B0, B ); XOR( h80211 + offset, B, n ); XOR( MIC, h80211 + offset, n ); aes_encrypt( &aes_ctx, MIC, MIC ); offset += n; } return( memcmp( h80211 + offset, MIC, 8 ) == 0 ); } struct decap_stats { unsigned long nb_read; /* # of packets read */ unsigned long nb_wep; /* # of WEP data packets */ unsigned long nb_wpa; /* # of WPA data packets */ unsigned long nb_plain; /* # of plaintext packets */ unsigned long nb_unwep; /* # of decrypted WEP pkt */ unsigned long nb_unwpa; /* # of decrypted WPA pkt */ } stats; struct options { int no_convert; char essid[36]; char passphrase[65]; uchar bssid[6]; uchar pmk[40]; uchar wepkey[64]; int weplen, crypt; } opt; uchar buffer[65536]; /* this routine handles to 802.11 to Ethernet translation */ int write_packet( FILE *f_out, struct pcap_pkthdr *pkh, uchar *h80211 ) { int n; uchar arphdr[12]; int qosh_offset = 0; if( opt.no_convert ) { if( buffer != h80211 ) memcpy( buffer, h80211, pkh->caplen ); } else { /* create the Ethernet link layer (MAC dst+src) */ switch( h80211[1] & 3 ) { case 0: /* To DS = 0, From DS = 0: DA, SA, BSSID */ memcpy( arphdr + 0, h80211 + 4, 6 ); memcpy( arphdr + 6, h80211 + 10, 6 ); break; case 1: /* To DS = 1, From DS = 0: BSSID, SA, DA */ memcpy( arphdr + 0, h80211 + 16, 6 ); memcpy( arphdr + 6, h80211 + 10, 6 ); break; case 2: /* To DS = 0, From DS = 1: DA, BSSID, SA */ memcpy( arphdr + 0, h80211 + 4, 6 ); memcpy( arphdr + 6, h80211 + 16, 6 ); break; default: /* To DS = 1, From DS = 1: RA, TA, DA, SA */ memcpy( arphdr + 0, h80211 + 16, 6 ); memcpy( arphdr + 6, h80211 + 24, 6 ); break; } /* check QoS header */ if ( GET_SUBTYPE(h80211[0]) == IEEE80211_FC0_SUBTYPE_QOS ) { qosh_offset += 2; } /* remove the 802.11 + LLC header */ if( ( h80211[1] & 3 ) != 3 ) { pkh->len -= 24 + qosh_offset + 6; pkh->caplen -= 24 + qosh_offset + 6; memcpy( buffer + 12, h80211 + 30 + qosh_offset, pkh->caplen ); } else { pkh->len -= 30 + qosh_offset + 6; pkh->caplen -= 30 + qosh_offset + 6; memcpy( buffer + 12, h80211 + 36 + qosh_offset, pkh->caplen ); } memcpy( buffer, arphdr, 12 ); pkh->len += 12; pkh->caplen += 12; } n = sizeof( struct pcap_pkthdr ); if( fwrite( pkh, 1, n, f_out ) != (size_t) n ) { perror( "fwrite(packet header) failed" ); return( 1 ); } n = pkh->caplen; if( fwrite( buffer, 1, n, f_out ) != (size_t) n ) { perror( "fwrite(packet data) failed" ); return( 1 ); } return( 0 ); } int main( int argc, char *argv[] ) { time_t tt; uint magic; char *s, buf[128]; FILE *f_in, *f_out; unsigned long crc; int i = 0, n, z, linktype; uchar ZERO[32], *h80211; uchar bssid[6], stmac[6]; struct ST_info *st_1st; struct ST_info *st_cur; struct ST_info *st_prv; struct pcap_file_header pfh; struct pcap_pkthdr pkh; /* parse the arguments */ memset( ZERO, 0, sizeof( ZERO ) ); memset( &opt, 0, sizeof( opt ) ); while( 1 ) { int option_index = 0; static struct option long_options[] = { {"bssid", 1, 0, 'b'}, {"debug", 1, 0, 'd'}, {"help", 0, 0, 'H'}, {0, 0, 0, 0 } }; int option = getopt_long( argc, argv, "lb:k:e:p:w:H", long_options, &option_index ); if( option < 0 ) break; switch( option ) { case ':' : printf("\"%s --help\" for help.\n", argv[0]); return( 1 ); case '?' : printf("\"%s --help\" for help.\n", argv[0]); return( 1 ); case 'l' : opt.no_convert = 1; break; case 'b' : i = 0; s = optarg; while( sscanf( s, "%x", &n ) == 1 ) { if( n < 0 || n > 255 ) { printf( "Invalid BSSID (not a MAC).\n" ); printf("\"%s --help\" for help.\n", argv[0]); return( 1 ); } opt.bssid[i] = n; if( ++i > 6 ) break; if( ! ( s = strchr( s, ':' ) ) ) break; s++; } if( i != 6 ) { printf( "Invalid BSSID (not a MAC).\n" ); printf("\"%s --help\" for help.\n", argv[0]); return( 1 ); } break; case 'k' : if( opt.crypt != CRYPT_NONE ) { printf( "Encryption key already specified.\n" ); printf("\"%s --help\" for help.\n", argv[0]); return( 1 ); } opt.crypt = CRYPT_WPA; i = 0; s = optarg; buf[0] = s[0]; buf[1] = s[1]; buf[2] = '\0'; while( sscanf( buf, "%x", &n ) == 1 ) { if( n < 0 || n > 255 ) { printf( "Invalid WPA PMK.\n" ); printf("\"%s --help\" for help.\n", argv[0]); return( 1 ); } opt.pmk[i++] = n; if( i >= 32 ) break; s += 2; if( s[0] == ':' || s[0] == '-' ) s++; if( s[0] == '\0' || s[1] == '\0' ) break; buf[0] = s[0]; buf[1] = s[1]; } if( i != 32 ) { printf( "Invalid WPA PMK.\n" ); printf("\"%s --help\" for help.\n", argv[0]); return( 1 ); } break; case 'e' : if ( opt.essid[0]) { printf( "ESSID already specified.\n" ); printf("\"%s --help\" for help.\n", argv[0]); return( 1 ); } memset( opt.essid, 0, sizeof( opt.essid ) ); strncpy( opt.essid, optarg, sizeof( opt.essid ) - 1 ); break; case 'p' : if( opt.crypt != CRYPT_NONE ) { printf( "Encryption key already specified.\n" ); printf("\"%s --help\" for help.\n", argv[0]); return( 1 ); } opt.crypt = CRYPT_WPA; memset( opt.passphrase, 0, sizeof( opt.passphrase ) ); strncpy( opt.passphrase, optarg, sizeof( opt.passphrase ) - 1 ); break; case 'w' : if( opt.crypt != CRYPT_NONE ) { printf( "Encryption key already specified.\n" ); printf("\"%s --help\" for help.\n", argv[0]); return( 1 ); } opt.crypt = CRYPT_WEP; i = 0; s = optarg; buf[0] = s[0]; buf[1] = s[1]; buf[2] = '\0'; while( sscanf( buf, "%x", &n ) == 1 ) { if( n < 0 || n > 255 ) { printf( "Invalid WEP key.\n" ); printf("\"%s --help\" for help.\n", argv[0]); return( 1 ); } opt.wepkey[i++] = n; if( i >= 64 ) break; s += 2; if( s[0] == ':' || s[0] == '-' ) s++; if( s[0] == '\0' || s[1] == '\0' ) break; buf[0] = s[0]; buf[1] = s[1]; } if( i != 5 && i != 13 && i != 16 && i != 29 && i != 61 ) { printf( "Invalid WEP key length. [5,13,16,29,61]\n" ); printf("\"%s --help\" for help.\n", argv[0]); return( 1 ); } opt.weplen = i; break; case 'H' : printf( usage, getVersion("Airdecap-ng", _MAJ, _MIN, _SUB_MIN, _REVISION) ); return( 1 ); default : goto usage; } } if( argc - optind != 1 ) { if(argc == 1) { usage: printf( usage, getVersion("Airdecap-ng", _MAJ, _MIN, _SUB_MIN, _REVISION) ); } if( argc - optind == 0) { printf("No file to decrypt specified.\n"); } if(argc > 1) { printf("\"%s --help\" for help.\n", argv[0]); } return( 1 ); } if( opt.crypt == CRYPT_WPA ) { if( opt.passphrase[0] != '\0' ) { /* compute the Pairwise Master Key */ if( opt.essid[0] == '\0' ) { printf( "You must also specify the ESSID (-e).\n" ); printf("\"%s --help\" for help.\n", argv[0]); return( 1 ); } calc_pmk( opt.passphrase, opt.essid, opt.pmk ); } } /* open the input and output pcap files */ if( ( f_in = fopen( argv[optind], "rb" ) ) == NULL ) { perror( "fopen failed\n" ); printf( "Could not open \"%s\".\n", argv[optind] ); return( 1 ); } n = sizeof( pfh ); if( fread( &pfh, 1, n, f_in ) != (size_t) n ) { perror( "fread(pcap file header) failed" ); return( 1 ); } if( pfh.magic != TCPDUMP_MAGIC && pfh.magic != TCPDUMP_CIGAM ) { printf( "\"%s\" isn't a pcap file (expected " "TCPDUMP_MAGIC).\n", argv[optind] ); return( 1 ); } if( ( magic = pfh.magic ) == TCPDUMP_CIGAM ) SWAP32( pfh.linktype ); if( pfh.linktype != LINKTYPE_IEEE802_11 && pfh.linktype != LINKTYPE_PRISM_HEADER && pfh.linktype != LINKTYPE_RADIOTAP_HDR ) { printf( "\"%s\" isn't a regular 802.11 " "(wireless) capture.\n", argv[optind] ); return( 1 ); } linktype = pfh.linktype; n = strlen( argv[optind] ); if( n > 4 && ( n + 5 < (int) sizeof( buffer ) ) && argv[optind][n - 4] == '.' ) { memcpy( buffer, argv[optind], n - 4 ); memcpy( buffer + n - 4, "-dec", 4 ); memcpy( buffer + n, argv[optind] + n - 4, 5 ); } else { if( n > 5 && ( n + 6 < (int) sizeof( buffer ) ) && argv[optind][n - 5] == '.' ) { memcpy( buffer, argv[optind], n - 5 ); memcpy( buffer + n - 5, "-dec", 4 ); memcpy( buffer + n - 1, argv[optind] + n - 5, 6 ); } else { memset( buffer, 0, sizeof( buffer ) ); snprintf( (char *) buffer, sizeof( buffer ) - 1, "%s-dec", argv[optind] ); } } if( ( f_out = fopen( (char *) buffer, "wb+" ) ) == NULL ) { perror( "fopen failed" ); printf( "Could not create \"%s\".\n", buffer ); return( 1 ); } pfh.magic = TCPDUMP_MAGIC; pfh.version_major = PCAP_VERSION_MAJOR; pfh.version_minor = PCAP_VERSION_MINOR; pfh.thiszone = 0; pfh.sigfigs = 0; pfh.snaplen = 65535; pfh.linktype = ( opt.no_convert ) ? LINKTYPE_IEEE802_11 : LINKTYPE_ETHERNET; n = sizeof( pfh ); if( fwrite( &pfh, 1, n, f_out ) != (size_t) n ) { perror( "fwrite(pcap file header) failed" ); return( 1 ); } /* loop reading and deciphering the packets */ memset( &stats, 0, sizeof( stats ) ); tt = time( NULL ); st_1st = NULL; while( 1 ) { if( time( NULL ) - tt > 0 ) { /* update the status line every second */ printf( "\33[KRead %ld packets...\r", stats.nb_read ); fflush( stdout ); tt = time( NULL ); } /* read one packet */ n = sizeof( pkh ); if( fread( &pkh, 1, n, f_in ) != (size_t) n ) break; if( magic == TCPDUMP_CIGAM ) SWAP32( pkh.caplen ); n = pkh.caplen; if( n <= 0 || n > 65535 ) { printf( "Corrupted file? Invalid packet length %d.\n", n ); break; } if( fread( buffer, 1, n, f_in ) != (size_t) n ) break; stats.nb_read++; h80211 = buffer; if( linktype == LINKTYPE_PRISM_HEADER ) { /* remove the prism header */ if( h80211[7] == 0x40 ) n = 64; /* prism54 */ else { n = *(int *)( h80211 + 4 ); if( magic == TCPDUMP_CIGAM ) SWAP32( n ); } if( n < 8 || n >= (int) pkh.caplen ) continue; h80211 += n; pkh.caplen -= n; } if( linktype == LINKTYPE_RADIOTAP_HDR ) { /* remove the radiotap header */ n = *(unsigned short *)( h80211 + 2 ); if( n <= 0 || n >= (int) pkh.caplen ) continue; h80211 += n; pkh.caplen -= n; } /* remove the FCS if present (madwifi) */ if( check_crc_buf( h80211, pkh.caplen - 4 ) == 1 ) { pkh.len -= 4; pkh.caplen -= 4; } /* check if data */ if( ( h80211[0] & 0x0C ) != 0x08 ) continue; /* check minimum size */ z = ( ( h80211[1] & 3 ) != 3 ) ? 24 : 30; if( z + 16 > (int) pkh.caplen ) continue; /* check QoS header */ if ( GET_SUBTYPE(h80211[0]) == IEEE80211_FC0_SUBTYPE_QOS ) { z += 2; } /* check the BSSID */ switch( h80211[1] & 3 ) { case 0: memcpy( bssid, h80211 + 16, 6 ); break; case 1: memcpy( bssid, h80211 + 4, 6 ); break; case 2: memcpy( bssid, h80211 + 10, 6 ); break; default: memcpy( bssid, h80211 + 4, 6 ); break; } if( memcmp( opt.bssid, ZERO, 6 ) != 0 ) if( memcmp( opt.bssid, bssid, 6 ) != 0 ) continue; /* locate the station's MAC address */ switch( h80211[1] & 3 ) { case 1: memcpy( stmac, h80211 + 10, 6 ); break; case 2: memcpy( stmac, h80211 + 4, 6 ); break; case 3: memcpy( stmac, h80211 + 10, 6 ); break; default: continue; } st_prv = NULL; st_cur = st_1st; while( st_cur != NULL ) { if( ! memcmp( st_cur->stmac, stmac, 6 ) ) break; st_prv = st_cur; st_cur = st_cur->next; } /* if it's a new station, add it */ if( st_cur == NULL ) { if( ! ( st_cur = (struct ST_info *) malloc( sizeof( struct ST_info ) ) ) ) { perror( "malloc failed" ); break; } memset( st_cur, 0, sizeof( struct ST_info ) ); if( st_1st == NULL ) st_1st = st_cur; else st_prv->next = st_cur; memcpy( st_cur->stmac, stmac, 6 ); memcpy( st_cur->bssid, bssid, 6 ); } /* check if we haven't already processed this packet */ crc = calc_crc_buf( h80211 + z, pkh.caplen - z ); if( ( h80211[1] & 3 ) == 2 ) { if( st_cur->t_crc == crc ) continue; st_cur->t_crc = crc; } else { if( st_cur->f_crc == crc ) continue; st_cur->f_crc = crc; } /* check the SNAP header to see if data is encrypted * * as unencrypted data begins with AA AA 03 00 00 00 */ if( h80211[z] != h80211[z + 1] || h80211[z + 2] != 0x03 ) { /* check the extended IV flag */ if( ( h80211[z + 3] & 0x20 ) == 0 ) { uchar K[64]; stats.nb_wep++; if( opt.crypt != CRYPT_WEP ) continue; memcpy( K, h80211 + z, 3 ); memcpy( K + 3, opt.wepkey, opt.weplen ); if( decrypt_wep( h80211 + z + 4, pkh.caplen - z - 4, K, 3 + opt.weplen ) == 0 ) continue; /* WEP data packet was successfully decrypted, * * remove the WEP IV & ICV and write the data */ pkh.len -= 8; pkh.caplen -= 8; memcpy( h80211 + z, h80211 + z + 4, pkh.caplen - z ); stats.nb_unwep++; h80211[1] &= 0xBF; if( write_packet( f_out, &pkh, h80211 ) != 0 ) break; } else { stats.nb_wpa++; if( opt.crypt != CRYPT_WPA ) continue; /* if the PTK is valid, try to decrypt */ if( st_cur == NULL || ! st_cur->valid_ptk ) continue; if( st_cur->keyver == 1 ) { if( decrypt_tkip( h80211, pkh.caplen, st_cur->ptk + 32 ) == 0 ) continue; pkh.len -= 20; pkh.caplen -= 20; } else { if( decrypt_ccmp( h80211, pkh.caplen, st_cur->ptk + 32 ) == 0 ) continue; pkh.len -= 16; pkh.caplen -= 16; } /* WPA data packet was successfully decrypted, * * remove the WPA Ext.IV & MIC, write the data */ memcpy( h80211 + z, h80211 + z + 8, pkh.caplen - z ); stats.nb_unwpa++; h80211[1] &= 0xBF; if( write_packet( f_out, &pkh, h80211 ) != 0 ) break; } } else { /* check ethertype == EAPOL */ z += 6; if( h80211[z] != 0x88 || h80211[z + 1] != 0x8E ) { stats.nb_plain++; if( opt.crypt != CRYPT_NONE ) continue; if( write_packet( f_out, &pkh, h80211 ) != 0 ) break; } z += 2; /* type == 3 (key), desc. == 254 (WPA) or 2 (RSN) */ if( h80211[z + 1] != 0x03 || ( h80211[z + 4] != 0xFE && h80211[z + 4] != 0x02 ) ) continue; /* frame 1: Pairwise == 1, Install == 0, Ack == 1, MIC == 0 */ if( ( h80211[z + 6] & 0x08 ) != 0 && ( h80211[z + 6] & 0x40 ) == 0 && ( h80211[z + 6] & 0x80 ) != 0 && ( h80211[z + 5] & 0x01 ) == 0 ) { /* set authenticator nonce */ memcpy( st_cur->anonce, &h80211[z + 17], 32 ); } /* frame 2 or 4: Pairwise == 1, Install == 0, Ack == 0, MIC == 1 */ if( ( h80211[z + 6] & 0x08 ) != 0 && ( h80211[z + 6] & 0x40 ) == 0 && ( h80211[z + 6] & 0x80 ) == 0 && ( h80211[z + 5] & 0x01 ) != 0 ) { if( memcmp( &h80211[z + 17], ZERO, 32 ) != 0 ) { /* set supplicant nonce */ memcpy( st_cur->snonce, &h80211[z + 17], 32 ); } } /* frame 3: Pairwise == 1, Install == 1, Ack == 1, MIC == 1 */ if( ( h80211[z + 6] & 0x08 ) != 0 && ( h80211[z + 6] & 0x40 ) != 0 && ( h80211[z + 6] & 0x80 ) != 0 && ( h80211[z + 5] & 0x01 ) != 0 ) { if( memcmp( &h80211[z + 17], ZERO, 32 ) != 0 ) { /* set authenticator nonce */ memcpy( st_cur->anonce, &h80211[z + 17], 32 ); } /* copy the MIC & eapol frame */ st_cur->eapol_size = ( h80211[z + 2] << 8 ) + h80211[z + 3] + 4; memcpy( st_cur->keymic, &h80211[z + 81], 16 ); memcpy( st_cur->eapol, &h80211[z], st_cur->eapol_size ); memset( st_cur->eapol + 81, 0, 16 ); /* copy the key descriptor version */ st_cur->keyver = h80211[z + 6] & 7; } st_cur->valid_ptk = calc_ptk( st_cur, opt.pmk ); } } fclose( f_in ); fclose( f_out ); /* write some statistics */ printf( "\33[KTotal number of packets read % 8ld\n" "Total number of WEP data packets % 8ld\n" "Total number of WPA data packets % 8ld\n" "Number of plaintext data packets % 8ld\n" "Number of decrypted WEP packets % 8ld\n" "Number of decrypted WPA packets % 8ld\n", stats.nb_read, stats.nb_wep, stats.nb_wpa, stats.nb_plain, stats.nb_unwep, stats.nb_unwpa ); return( 0 ); }