Parameter Injection

In this challenge, we are acting as the MiTM which will intercept the key exchange messages between Alice and Bob. We are able to modify the A and B - each of the shared secret by doing g^a and g^b of Alice and Bob. The flag is sent from Alice to Bob, hence we only need to care about the response of the key exchange message from Bob to Alice. Recall that when Bob’s secret B is sent over to Alice, Alice will do B^a on her side, where a is the secret of Alice....