How to intercept Skype text traffic on a router?

Question

linux

Good afternoon everyone. Task: there is a router based on the Linux kernel. There is a network on how many computers. Question - is it possible to somehow intercept Skype chat packets on the router and log sent / received messages? Thank you.

Answer 1

Skype traffic is encrypted, and quite well. Perhaps it would be better for you to pick up text logs on your computer, unless you are of course FSB :)

Answer 2

If it is possible to intercept them, then they will still need to be decrypted (the text is also encrypted).

Skype developers warn administrators against attempts to identify and block its traffic (such as: "You won't succeed anyway!"). Indeed, it is very difficult to recognize Skype traffic, and it can only be blocked by content that is encrypted and does not contain any predictable sequences.

Link with details .

Answer 3

And for example, the password is also transmitted in encrypted form?

Answer 4

Thanks everyone for the replies.

Answer 5

Passwords there are generally encrypted at the authentication stage very cleverly. The client generates a temporary 1024-bit RSA key pair, a 256-bit AES session key, then encrypts the packet (session public RSA key, login, SHA1(password)) with AES, then encrypts the AES session key using the public key of the Skype server, and sends these two packets to the server for authentication. It’s hard to get something out of here :)
When users communicate with each other P2P, they authenticate each other through 8 bytes of challenge-response, according to their certificates, exchange 128 bit sequences with each other, collect a 256 bit AES key from them and the entire subsequent session is encrypted already them.
Read the documentation on reverse engineering of the protocol, it is on the first links in Google.