Bug 1411238

Summary:	openssl switches to (SHA1, RSA) if no usable signature algorithm is specified
Product:	Red Hat Enterprise Linux 7	Reporter:	Stanislav Zidek <szidek>
Component:	openssl	Assignee:	Tomas Mraz <tmraz>
Status:	CLOSED ERRATA	QA Contact:	Stefan Dordevic <sdordevi>
Severity:	medium	Docs Contact:
Priority:	medium
Version:	7.3	CC:	sdordevi
Target Milestone:	rc	Keywords:	Reopened
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Hardware:	All
OS:	Linux
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Last Closed:	2017-08-01 18:16:10 UTC	Type:	Bug
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Description Stanislav Zidek 2017-01-09 08:48:42 UTC

Description of problem:
If client sends only (MD5, RSA) in signature algorithms in ClientHello (or any other combination not supported by the server), it uses (SHA1, RSA) by default. This violates RFC 5246 (see bz1410573 for further details).

Version-Release number of selected component (if applicable):
openssl-1.0.1e-60.el7

How reproducible:
always

Steps to Reproduce:
1. start s_server
2. send ClientHello containing only (MD5, RSA) signature algorithm
3. look at signature algorithm used in ServerKeyExchange

Actual results:
(SHA1, RSA) is used

Expected results:
Connection is aborted.

Additional info:
This is already fixed in openssl-1.0.2j-1.fc24

Comment 2 Tomas Mraz 2017-04-03 14:34:41 UTC


*** This bug has been marked as a duplicate of bug 1276310 ***

Comment 6 errata-xmlrpc 2017-08-01 18:16:10 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://access.redhat.com/errata/RHBA-2017:1929