chat_program_protocol.txt

1. Structure of a message in CPP (Chat Program Protocol):
       __________________________________________
index: |0            0|1            4|5      N+4|    sizes are in bytes.
field: |  [datatype]  | [datasize=N] |  [data]  |    big endian format.
size:  |______1_______|_______4______|____N_____|

[datatype] - the type of data (explanation below).
[datasize] - the size in bytes of [data], >=1.
[data] - variable sized data, interpreted according to [datatype].

Note: Some messsage types do not require the [data] field.
      Therefore, for some values of [datatype], the field [datasize] is 0 and [data] is omitted. 


[data] structure for each [datatype] value:
   MSG - [datatype]=0 :            ___________
                                   |5     N+4|
                                   |  [msg]  |
                                   |____N____|

   SERVERMSG - [datatype=1]:       ___________________________________________________
                                   |5           8|9           10|11    L+10|L+11  N+4|
                                   | [timestamp] | [namesize=L] |  [name]  |  [msg]  |
                                   |______4______|______2_______|_____L____|__N-L-6__|

   BYTES - [datatype=2]:           ___________
                                   |5     N+4|
                                   | [bytes] |
                                   |____N____|

   FILE_ATTACH - [datatype=3]:     ___________
                                   |5     N+4|
                                   | [bytes] |
                                   |____N____|

   TELL - [datatype=129] :         ___________________________________
                                   |5            6|7    L+6|L+7   N+4|
                                   | [namesize=L] | [name] |  [msg]  |
                                   |______2_______|___L____|__N-L-2__|

   KICK \ PROMOTE \ DEMOTE \ MUTE \ UNMUTE - [datatype]=130\131\132\133\134 :
                                   ____________
                                   |5      N+4|
                                   |  [name]  |
                                   |____N_____|

    HELP - [datatype]=193 :  *[data] omitted*

    QUIT - [datatype]=194 :  *[data] omitted*

    VIEW - [datatype]=195 :  *[data] omitted*


2. CPPS (Chat Program Protocol Secure)
CPPS provides a security layer to the regular CP protocol.
CPPS messages are AES-encrypted CPP messages, therefore their structure is uniform. 
Structure of a message in CPPS (Chat Program Protocol Secure):
       ___________________________________________________________________
index: |0            3|4           19|20          35|36               N+3|    sizes are in bytes.
field: | [datasize=N] |   [nonce]    |    [tag]     |  [ecncrypted-msg]  |    big endian format.
size:  |______4_______|______16______|______16______|________N-32________|