Didn't quite understood the checks, but here is an idea: If you can make a user supplied point NOT ON THE curve to be accepted as valid, this might break the other private key (basically it is working on another curve, leaking info about the private key).
There is a document describing the exact attack, if you can do this check for a start: http://crypto.stackexchange.com/questions/3820/why-do-public-keys-need-to-be-validated On Fri, Sep 13, 2013 at 08:11:47AM +0200, king cope wrote: > Hello lists, > > Attached is the blog post for the mentioned issues that in its shape > are not a vulnerability, still interesting to see. > > http://kingcope.wordpress.com/2013/09/13/opensslopenssh-ecdsa-authentication-code-inconsistent-return-values-no-vulnerability/ > > Cheers, > > Kingcope > > _______________________________________________ > Full-Disclosure - We believe in it. > Charter: http://lists.grok.org.uk/full-disclosure-charter.html > Hosted and sponsored by Secunia - http://secunia.com/ _______________________________________________ Full-Disclosure - We believe in it. Charter: http://lists.grok.org.uk/full-disclosure-charter.html Hosted and sponsored by Secunia - http://secunia.com/
