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 the BSSID */        switch( h80211[0] & 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 );}