host_header

校园网拨号端软件

This struct is used in non-message outgoing packets.

struct drcom_host_header
{
  u_int16_t pkt_type;
  u_int8_t zero;
  u_int8_t len;
  u_int8_t checksum[16];
} __attribute__ ((__packed__));

pkt_type and len are specific to the packet.

checksum0 is MD5 checksum of:
- pkt_type
- challenge value
- password (excluding null bytes)
concatenated together.

checksum0 may be not a checksum, such as in the request packet.