openComputers_codes/icable_server/protocol.txt

icable protocol

header :
|76543210|76543210|76543210|76543210|
|--------|--------|--------|--------|
|          MAGIC  "ICAB"            |
|--------|--------|--------|--------|
|  KIND  |  LEN            |RESERVED|
|--------|--------|--------|--------|

MAGIC (4B) : string "ICAB"
KIND (1B) : type of packet
	LSB indicate if the msg is for the server or for the client
	- CLIENT_AUTH (0x02)			: authentication request from the client
	- SERVER_AUTH (0x03)			: authentication answer from the server
	- CLIENT_NETCONF (0x04)			: network configuration request from the client
	- SERVER_NETCONF (0x05)			: network configuration answer from the server
	- CLIENT_AUTH_REQUEST (0x06)		: request a random string from the server to secure the authentication process
	- SERVER_AUTH_REQUEST (0x07)		: provide a random string to the client and it's password salt
	- CLIENT_ERROR (0xfa)			: error returned by the client
	- SERVER_ERROR (0xfb)			: error returned by the server
	- CLIENT_DISCONNECT (0xfc)		: client disconnection notification
	- SERVER_DISCONNECT (0xfd)		: server disconnection notification
	- CLIENT_DATA (0xfe)			: data packet sent from the client
	- SERVER_DATA (0xff)			: data packet sent by the server
LEN (2B) : total length data after the header
RESERVED (1B) : reserved for later use

CLIENT_AUTH :
A client authentication packet contain 4 fields :
- username len (1B) : the username string length in bytes
- username (username len) : the username string
- password len (1B) : the password length in bytes
- password (password len) : the password string

If a CLIENT_AUTH_REQUEST was sent and a CLIENT_AUTH_REQUEST was received, the password field contain sha256(srvsalt..sha256(salt..password)) where srvsalt and salt were provided by the srv via SERVER_AUTH_REQUEST

SERVER_AUTH :
A server authentication packet contain 1 fields :
- success (1B) : set to 0x00 if the authentication request was denied or 0xff is successful

CLIENT_NETCONF :
|76543210|76543210|76543210|76543210|
|--------|--------|--------|--------|
| KIND   |           IPv4           ~
|--------|--------|--------|--------|
~        | NMASK  |
|--------|--------|
KIND (1B) : kind of request :
	- MANUAL_IPv4 (0x01) : manual address request
	- AUTO_IPv4 (0x02) : automatic address attribution.
	- RESERVED (0x04) : avoid confusion with SERVER_NETCONF IPv4
If KIND is MANUAL the following fields must be present
IPv4 (4B) : requested ipv4 address
NMASK (1B) : requested ipv4 network mask
If KIND is AUTO_IPv4 the following fields may be present
IPv4 (4B) : network name the client want to be part of
NMAK (1B) : netmask of the network

SERVER_NETCONF 
If a CLIENT_NETCONF request is success, the server will respond with info about the client network configuration
|76543210|76543210|76543210|76543210|
|--------|--------|--------|--------|
| KIND   |           IPv4           ~
|--------|--------|--------|--------|
~        | NMASK  |
|--------|--------|
KIND (1B) : kind of address
	- IPv4 (0x04) : IPv4 address
IPv4 (4B) : IPv4 address attributed to the client
NMASK (4B) : network mask for the given IPv4 address

CLIENT_AUTH_REQUEST
Request random strings from the srv to secure the authentication
|76543210|76543210|76543210|76543210|
|--------|--------|--------|--------|
|UNAMELEN|          UNAME           ~
|--------|--------|--------|--------|
UNAMELEN (1B) length of the UNAME string
UNAME (UNAMELEN B) username
The srv will answer with a SERVER_AUTH with sucess 0x00 if the user doesn't exists

SERVER_AUTH_REQUEST
|76543210|76543210|76543210|76543210|76543210|76543210|76543210|76543210|
|--------|--------|--------|--------|--------|--------|--------|--------|
|                                  SALT                                 ~
|--------|--------|--------|--------|--------|--------|--------|--------|
~									|
|--------|--------|--------|--------|--------|--------|--------|--------|
|                                SRVSALT                                ~
|--------|--------|--------|--------|--------|--------|--------|--------|
~									|
|--------|--------|--------|--------|--------|--------|--------|--------|
SLAT(16B) : salt used to hash the password
SRVSALT(16B) : salt used to hash the slat+password hash

CLIENT_ERROR :
Error notification from the client.
|76543210|76543210|76543210|76543210|
| KIND   | MSGLEN          |  MSG   ~
|--------|--------|--------|--------|
~               ...                 |
|--------|--------|--------|--------|
KIND (1B) : kind of error
	- UNKNOWN_MSG (0x01) : the kind of message received is unknown to the client
MSGLEN (1B) : length of the error message string. May be 0
MSG (MSGLEN) : error message

SERVER_ERROR :
Error notification from the server.
|76543210|76543210|76543210|76543210|
| KIND   | MSGLEN          |  MSG   ~
|--------|--------|--------|--------|
~               ...                 |
|--------|--------|--------|--------|
KIND (1B) : kind of error
	- UNKNOWN_MSG (0x01) : the kind of message received is unknown to the server
	- NOT_AUTH (0x02) : client is not authenticated
	- NETCONF_ERROR (0x04) : invalid network configuration request
	- MISSING_NETCONF (0x05) : client didn't request a network configuration
	- NETCONF_MISSMATCH (0x06) : source address in IPv4 header doesn't match the client's configuration
MSGLEN (1B) : length of the error message string. May be 0
MSG (MSGLEN) : error message

CLIENT_DISCONNECT :
This msg is empty and is sent just before closing the socket. No answer is expected and the server should close his end of the socket as soon as possible.

SERVER_DISCONNECT :
This msg is empty and is sent just before closing the socket. No answer is expected and the client should close his end of the socket as soon as possible.

CLIENT_DATA :
Raw packet. Usually IPv4

SERVER_DATA :
Raw packet. Usually IPv4