134156 - lower limit for valid public key lengths in SSL et al.

Status: RESOLVED DUPLICATE of bug 134735

(Core Graveyard :: Security: UI, enhancement)

Description

[Sampo Syreeni]

In light of Berstein's recent paper on improving NFS factoring, it would seem
short keylengths (384,512 bits) in RSA can hardly be thought of as being safe.
Still, Verisign appears willing to sign such keys. Considering this, it would be
a Good Thing if one could set the various RSA-based protocols in Mozilla to
reject keys below a certain minimum size (treat them as invalid, or warni about
them otherwise). Quoting Len Sassaman on cypherpunks:

"On the client side, Internet browsers should have a mechanism for
specifying the minimum key size that a user is willing to accept to secure
his TLS/SSL connection. Not offering this as a standard feature, with sane
defaults, is downright negligent. Both Netscape/Mozilla and Microsoft
appear guilty of this."

I think this is one more possibility of getting ahead Microsoft, with minimal
trouble. ;)

Comment 1

[Wan-Teh Chang]

Assigned the bug to Nelson.

Comment 2

[Nelson Bolyard (seldom reads bugmail)]

This is really a mozilla/PSM request, not an NSS request.

Policy decisions about the acceptability of a certificate are outside
the scope of the SSL protocol (except as required by export regulations
of old).  It's really up to the application to determine and enforce its
own policies.  NSS provides the tools that the application can use for 
this.

LibSSL calls a callback (implemented and provided by the application)
to determine whether the cert(s) provided by the server are acceptable
to the application, or not.  LibNSS provides functions that the application
can call to validate the certs and cert chains, and to inspect the 
components of the certs (e.g. key size, key type, etc.).  

So, I submit that the requestor is actually proposing that mozilla/PSM should
have a new policy regarding minimum RSA key sizes, and should enforce that
policy for SSL.  I believe that NSS already provides all the necessary 
tools for Mozilla to do this.  If the submittor agrees, please change 
this bug to be an ehnahcement request for PSM.

Comment 3

[Sampo Syreeni]

Based on what's been said, agreed. I seem to have a lot to learn about Mozilla 
internals, still. ;) Changing program to PSM, aiming for the daemon.

Comment 4

[Nelson Bolyard (seldom reads bugmail)]

reassigning to PSM manager

Comment 5

[Wan-Teh Chang]

Changed the QA contact to Bishakha.

Comment 6

[John G. Myers]

Mass reassign ssaux bugs to nobody

Comment 7

[John G. Myers]

Bug 134735 addresses UI for SSL.  Bug 235972 addresses the keygen tag.