iwlist wpa

/*------------------------------------------------------------------*/
/*
 * Parse, and display the results of a WPA or WPA2 IE.
 *
 */
static inline void
iw_print_ie_wpa(unsigned char * iebuf,
        int     buflen)
{
  int           ielen = iebuf[1] + 2;
  int           offset = 2; /* Skip the IE id, and the length. */
  unsigned char     wpa1_oui[3] = {0x00, 0x50, 0xf2};
  unsigned char     wpa2_oui[3] = {0x00, 0x0f, 0xac};
  unsigned char *   wpa_oui;
  int           i;
  uint16_t      ver = 0;
  uint16_t      cnt = 0;

  if(ielen > buflen)
    ielen = buflen;

#ifdef DEBUG
  /* Debugging code. In theory useless, because it's debugged ;-) */
  printf("IE raw value %d [%02X", buflen, iebuf[0]);
  for(i = 1; i < buflen; i++)
    printf(":%02X", iebuf[i]);
  printf("]\n");
#endif

  switch(iebuf[0])
    {
    case 0x30:      /* WPA2 */
      /* Check if we have enough data */
      if(ielen < 4)
    {
      iw_print_ie_unknown(iebuf, buflen);
      return;
    }

      wpa_oui = wpa2_oui;
      break;

    case 0xdd:      /* WPA or else */
      wpa_oui = wpa1_oui;

      /* Not all IEs that start with 0xdd are WPA.
       * So check that the OUI is valid. Note : offset==2 */
      if((ielen < 8)
     || (memcmp(&iebuf[offset], wpa_oui, 3) != 0)
     || (iebuf[offset + 3] != 0x01))
    {
      iw_print_ie_unknown(iebuf, buflen);
      return;
    }

      /* Skip the OUI type */
      offset += 4;
      break;

    default:
      return;
    }

  /* Pick version number (little endian) */
  ver = iebuf[offset] | (iebuf[offset + 1] << 8);
  offset += 2;

  if(iebuf[0] == 0xdd)
    printf("WPA Version %d\n", ver);
  if(iebuf[0] == 0x30)
    printf("IEEE 802.11i/WPA2 Version %d\n", ver);

  /* From here, everything is technically optional. */

  /* Check if we are done */
  if(ielen < (offset + 4))
    {
      /* We have a short IE.  So we should assume TKIP/TKIP. */
      printf("                        Group Cipher : TKIP\n");
      printf("                        Pairwise Cipher : TKIP\n");
      return;
    }

  /* Next we have our group cipher. */
  if(memcmp(&iebuf[offset], wpa_oui, 3) != 0)
    {
      printf("                        Group Cipher : Proprietary\n");
    }
  else
    {
      printf("                        Group Cipher :");
      iw_print_value_name(iebuf[offset+3],
              iw_ie_cypher_name, IW_IE_CYPHER_NUM);
      printf("\n");
    }
  offset += 4;

  /* Check if we are done */
  if(ielen < (offset + 2))
    {
      /* We don't have a pairwise cipher, or auth method. Assume TKIP. */
      printf("                        Pairwise Ciphers : TKIP\n");
      return;
    }

  /* Otherwise, we have some number of pairwise ciphers. */
  cnt = iebuf[offset] | (iebuf[offset + 1] << 8);
  offset += 2;
  printf("                        Pairwise Ciphers (%d) :", cnt);

  if(ielen < (offset + 4*cnt))
    return;

  for(i = 0; i < cnt; i++)
    {
      if(memcmp(&iebuf[offset], wpa_oui, 3) != 0)
    {
      printf(" Proprietary");
    }
      else
    {
      iw_print_value_name(iebuf[offset+3],
                  iw_ie_cypher_name, IW_IE_CYPHER_NUM);
    }
      offset+=4;
    }
  printf("\n");

  /* Check if we are done */
  if(ielen < (offset + 2))
    return;

  /* Now, we have authentication suites. */
  cnt = iebuf[offset] | (iebuf[offset + 1] << 8);
  offset += 2;
  printf("                        Authentication Suites (%d) :", cnt);

  if(ielen < (offset + 4*cnt))
    return;

  for(i = 0; i < cnt; i++)
    {
      if(memcmp(&iebuf[offset], wpa_oui, 3) != 0)
    {
      printf(" Proprietary");
    }
      else
    {
      iw_print_value_name(iebuf[offset+3],
                  iw_ie_key_mgmt_name, IW_IE_KEY_MGMT_NUM);
    }
       offset+=4;
     }
  printf("\n");

  /* Check if we are done */
  if(ielen < (offset + 1))
    return;

  /* Otherwise, we have capabilities bytes.
   * For now, we only care about preauth which is in bit position 1 of the
   * first byte.  (But, preauth with WPA version 1 isn't supposed to be
   * allowed.) 8-) */
  if(iebuf[offset] & 0x01)
    {
      printf("                       Preauthentication Supported\n");
    }
}