Re: [Trans] [trans] #80 (rfc6962-bis): Re-introduce the issuer key hash into the Precertificate

["trans issue tracker" <[e-mail]>]

#80: Re-introduce the issuer key hash into the Precertificate


Comment (by [e-mail]):

 This problem affects browser clients and any other client that wants to
 verify that an SCT corresponds to a particular cert.  A browser has the
 full cert chain (from the TLS handshake) and the corresponding SCTs, but
 it is _not_ expected to have the full log entries (i.e. extra_data, etc).

 In the current text, the SCT is bound to the Issuer Name (because that's
 in the TBSCertificate), but not to the Issuer Key (because that's not in
 the TBSCertificate).

 There could exist two or more publicly-trusted intermediate CA certs with
 the same Name but different Keys.  One of those intermediates might be
 logged, while the other(s) are not logged.  Each of them could issue leaf
 certs that have an identical TBSCertificate.  Only one of those leaf certs
 needs to be logged for there to exist SCT(s) that are valid for all of
 those leaf certs.

 The logged leaf cert might get revoked, but the other(s) might not get
 revoked.  However, the SCT(s) would still work for all of those certs,
 including the non-logged ones.

 Therefore, we need to fix SCTs so that they're bound to the Issuer Key
 Hash as well as the Issuer Name.

-- 
------------------------------+---------------------------------------
 Reporter:  [e-mail]  |       Owner:  [e-mail]
     Type:  defect            |      Status:  assigned
 Priority:  major             |   Milestone:
Component:  rfc6962-bis       |     Version:
 Severity:  -                 |  Resolution:
 Keywords:                    |
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Ticket URL: <http://trac.tools.ietf.org/wg/trans/trac/ticket/80#comment:4>
trans <http://tools.ietf.org/trans/>