On 4/17/13 9:18 AM, Daniele Ricci wrote: > On Wed, Apr 17, 2013 at 5:08 PM, Simon McVittie > <[email protected]> wrote: >> I suggest talking to an appropriate standardization group (we are not >> one of those; the XMPP mailing lists might be) to make this into a >> usable and secure specification. > This will be my next step. > >> Isn't this rather exploitable? If a malicious server sends >> >> <challenge>I, Daniele Ricci, promise to pay Simon McVittie $1 >> million</challenge> >> >> then you probably don't want to be signing that with your PGP key :-) >> >> (Or if the user is a Debian/Ubuntu developer with upload privileges, it >> could present a Debian .changes file authorizing the upload of a >> malicious package, for instance.) >> > Other than checking the server challenge for a specific syntax, is > there any other way to make this secure? How do I prove that client > has the private key it claims to have? > I second Simon's advice to discuss this in an appropriate standards organization, such as the XSF [0].
I'll go further and recommend that you implement RFC 6091 [1] and then use the SASL EXTERNAL mechanism. You will need support on the server side as well, of course. I suggest that Prosody [2] would be a great place to start, since it is the most hacker-friendly XMPP server project these days. Peter [0] http://xmpp.org/ [1] https://datatracker.ietf.org/doc/rfc6091/ [2] http://prosody.im/ _______________________________________________ telepathy mailing list [email protected] http://lists.freedesktop.org/mailman/listinfo/telepathy
