Bug 1269239

Summary: NSS does not support all signature methods for Certificate Verify [rhel-6]
Product: Red Hat Enterprise Linux 6 Reporter: Hubert Kario <hkario>
Component: nssAssignee: Daiki Ueno <dueno>
Status: CLOSED ERRATA QA Contact: Hubert Kario <hkario>
Severity: high Docs Contact:
Priority: high    
Version: 6.7CC: bryanlharris, dueno, emaldona, hkario, kengert, mpoole, nkinder, omoris, pvrabec, qe-baseos-security, rrelyea, rsawhill
Target Milestone: rc   
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard:
Fixed In Version: nss-3.27.1-6.el6 Doc Type: If docs needed, set a value
Doc Text:
Story Points: ---
Clone Of: 1238369 Environment:
Last Closed: 2017-03-21 10:25:41 UTC Type: Bug
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On: 1238369    
Bug Blocks: 1172231, 1271982, 1321112, 1343211    

Description Hubert Kario 2015-10-06 18:54:47 UTC
+++ This bug was initially created as a clone of Bug #1238369 +++

Description of problem:
NSS client can sign Certificate Verify only using SHA256 (the PRF used in ciphersuite) or SHA-1. NSS server requests signature on Certificate Verify only using SHA256 (the PRF used). This makes servers unable to interoperate with clients that can sign only using SHA-1. 

Version-Release number of selected component (if applicable):
nss-3.19.1-5.el7_1

How reproducible:
Always

Steps to Reproduce:
1. Use NSS as client or server in connections that require certificates in TLSv1.2

Actual results:
Certificate Verify always is signed using SHA-256 by NSS client
Certificate Request always asks just for RSA+SHA256, DSA+SHA256 or ECDSA+SHA256

Expected results:
most hashes listed as acceptable by server, especially DSA+SHA1 or RSA+SHA1

Additional info:

--- Additional comment from Hubert Kario on 2015-08-12 09:42:35 EDT ---

This feature is necessary for interoperability between GnuTLS and NSS with TLS_DHE_DSS_WITH_AES_256_GCM_SHA384 ciphersuite and DSA client certificates in TLSv1.2.

--- Additional comment from Hubert Kario on 2015-09-15 13:25:33 EDT ---

This issue breaks communication with Microsoft Internet Explorer clients that have certificates signed with algorithms different than SHA-256.

Since the server asks only for SHA256 signatures, the client refuses to provide its certificate and aborts the connection.

This is the expected behaviour according to https://tools.ietf.org/html/rfc5246#section-7.4.4

Comment 30 errata-xmlrpc 2017-03-21 10:25:41 UTC
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://rhn.redhat.com/errata/RHEA-2017-0671.html