[openssl-dev] Need CVE-2015-3193 impact explained

[Viktor Dukhovni]

On Mon, Dec 07, 2015 at 10:53:15AM +0100, Leif Thuresson wrote:

> The description of CVE-2015-3193 in 2015-12-04 security advisory
> states that EC algorithms are not affected, but attacks against DH are
> considered feasible.

DH as distinct from ECDH.  The issue affects modular exponentiation
which is used in RSA and (finite-field) DH, but not ECDSA or ECDH.

> Not being a cryptographer that leaves me a bit confused.
> Are applications supporting cipher suites with ECDHE- variants vulnerable?

Only to the extent that they are already vulnerable as a result of
using RSA certificates to sign the key exchange parameters.  The
key exchange itself is not.

-- 
	Viktor.