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Re: Secdir Review of draft-ietf-netconf-rfc5539bis-09

2015-03-11 02:35:34
On Wed, Mar 11, 2015 at 08:15:59AM +0100, Juergen Schoenwaelder wrote:

The I-D specifies fingerprint of the certificate so that is specified.

Normalisation is not specified and is an interesting point; as you say,
something to be considered.

The certificate should not be normalized.  Rather the "locally configured"
fingerprint needs to match the certificate as it is expected to be presented.

The model follows RFC 6353 (STD 78) and I am not aware of any issues
that were reported against STD 78 because fingerprints do have issues
with being ambiguous. So are we talking about a real-world problem or
a problem that could exist in theory?

Since the fingerprint is configured via some out-of-band process
that establishes authorized access for the holders of the associated
private keys, its represenation is largely irrelevant.  Any strong
cryptographic binding of the certificate (or bare public key) will
do.

In particular the draft should mention that fingerprints of raw
public keys are also acceptable (and might some day even be used
directly on the wire per RFC 7250).

FWIW, the Postfix MTA has supported authentication of remote SMTP
clients and servers by certificate fingerprint (since 2005 and 2008
respectively) and also by public key (SPKI) fingerprint (since 2012).

No normalization of the certificate is performed, the ASN.1 form
of the certificate is as encoded by the peer.

-- 
        Viktor.