Ning wrote: > I'm trying to write an IM client which sends encrypted messages to the > server. I tried to use pycrypto library, but when I came to 3DES > cypher I was confused about the keysize to use. In the standard it > said that it should be either 112 bits or 168 bits, whereas it's 16 > bytes or 24 bytes in pycrypto. If I use 16 bytes key to encrypt and > send this key to the server which is expecting a 112 bits key, there'll > be a problem. How I should solve this?
You need to account for the parity bits: http://en.wikipedia.org/wiki/Triple_DES If that may reassure you ;-) I use PyCrypto to "talk" to smart cards without any problem. hg -- http://mail.python.org/mailman/listinfo/python-list
