Protecting my TCP or UDP conenction.
Hi!
I have a client and a server which communicate through TCP and UDP.
I'd like to prevent receiving messages from other processes that may try to connect to my ports.
I take the stream of bytes and make an object out of it, but if this is just a random stream - the program will crash.
How can I do it?
thanks :)
I have a client and a server which communicate through TCP and UDP.
I'd like to prevent receiving messages from other processes that may try to connect to my ports.
I take the stream of bytes and make an object out of it, but if this is just a random stream - the program will crash.
How can I do it?
thanks :)
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Just make your header longer, e.g. as in the example above. It would be *very* coincidential that four bytes match by chance.
In any case, you need to make your protocol implementation robust enough to handle bad packets.
At minimum use a giant try/catch block to discard message and close the connection. It shouldnt be possible to crash your app with a bad packet.
At minimum use a giant try/catch block to discard message and close the connection. It shouldnt be possible to crash your app with a bad packet.
Are you trying to protect against malice, or against an accident ?
ASKER
against accidents :)
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I'd rather combine the two ideas - that is, if the header does not match, you can skip calculating a checksum, but if it does, a matching checksum will make absolutely sure that the packet originated from a trustworthy source.
ASKER
suppose I put in my header the letter 'A' and the length of the message and so does the other process?