new encryption algorithm for ssh

Question

I am asked to add a new algorithm to ssh so data is ciphered in new algorithm, any idea how to add new algorithm to ssh ?

thanks

Answer 1

It is possible to add some new algorithm to SSH communication, and this is done from time to time (eg. AES was added later). But the question is that you need to modify both client and server so that they both support this algorithm, otherwise it makes no sense.

I assume that you were asked to add some custom, either home-made or non-standard algorithm. So first thing I'd like to do is to warn you that the added algorithm can be weak. You need to perform at least basic search for information about this algorithm, as if it's broken, you will do completely useless and even dangerous work.

As for software modification themselves - it's a rare job to do so most likely you won't find anybody with this experience there. However the code that handles various algorithms is typical and adding new algorithm is trivial - you add one source file with algorithm implementation and then modify a bunch of places by adding one more case to switch statement.