Fake server for RSA SecurID token generation (see https://github.com/dlenski/rsa_ct_kip#fake-server)

fakeserver.py

#!/usr/bin/env python3

# Needs: Python 3.5+, Flask, PyCryptoDome
#        server.pem, rsapubkey.pem + rsaprivkey.pem (1024-bit) in the current directory
# 
# What it does:
#   Pretends to be the "CT-KIP" web service (https://tools.ietf.org/html/rfc3948) that
#   RSA SecurID Token for Windows v5.0.x talks to to set up a new token, using an
#   authentication code.
#
# This has been turned into a "real" repository.
#
# See https://github.com/dlenski/rsa_ct_kip#fake-server and use that instead of
# the (no-longer-maintained) contents of this gist.

Yeah, that looks plausibly right to me.

I hope the RSA pubkey representation fed into the PRF isn't .der and especially PEM, but I don't really know. Could try the DER order (modulus n, followed by exponent e), but I don't know how long of an encoding e would have. Then again PKCS 1 specifies e=65537, so maybe just try the (big-endian, i.e., I2OSP) modulus (which should have an exact encoding width).

I agree that K_TOKEN for K_AUTH looks reasonable for §3.8.6.

Yeah. I've hunted around a little bit and I'm having trouble finding any other CT-KIP-PRF implementation to compare against (not the same as known test vectors, but better than nothing). I wonder if the (single) MAC in https://tools.ietf.org/html/draft-nystrom-ct-kip-two-pass-01#page-30 is a valid test vector. But I have not investigated what it is supposed to be over, or if the key is even supplied.

Um, call me crazy, but isn't CT-KIP-PRF-AES identical to DSKPP-PRF-AES? Even the diagrams and language in RFC 6063 seem derivative of RFC 4758. And indeed our friend Magnus who authored the first RFC is an author on the second. Still no explicit known vectors, but some different MACs that may or may not be correct, anyway. Or maybe there are implementations, I don't know (didn't find any with a very quick google search).

Yeah, we have a very low information oracle on whether we got it right. Hmm. Maybe reversing the client would be more straightforward.

By the way, I don't get notifications of gist replies, so I might miss further discussion here. But we have lots of options :-).

hi, I would like to ask what is the functionality of this code. Is it a localhost server where I could emulate SecureId app? Thank you very much

Is it a localhost server where I could emulate SecureId app? Thank you very much

@leonardorobertolopez Yes. To be clear, it emulates the server used for provisioning SecurID tokens using the "RSA CT-KIP" protocol.

It has been turned into a "real" repository, though. See https://github.com/dlenski/rsa_ct_kip#fake-server and use that instead.