Bug 910815

Summary: unable to verify SSL certificate hostname
Product: [Fedora] Fedora Reporter: Kamil Dudka <kdudka>
Component: nss_compat_osslAssignee: Orphan Owner <extras-orphan>
Status: NEW --- QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: medium Docs Contact:
Priority: medium    
Version: 23CC: fweimer, kdudka, mharmsen, nkinder, ovasik, rcritten, rrelyea, vdanen
Target Milestone: ---Keywords: Security, SecurityTracking
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard: fst_ping=1
Fixed In Version: Doc Type: Release Note
Doc Text:
Story Points: ---
Clone Of: 881411 Environment:
Last Closed: Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Bug Depends On:    
Bug Blocks: 881399, 881411    

Description Kamil Dudka 2013-02-13 11:10:50 EST
+++ This bug was initially created as a clone of Bug #881411 +++

--- Additional comment from Kamil Dudka on 2012-12-03 16:59:20 CET ---

This seems to be the upstream fix:

http://repo.or.cz/w/elinks.git/commitdiff/0c3f3e09

--- Additional comment from Kamil Dudka on 2012-12-03 17:14:26 CET ---

nss_compat_ossl does not seem to be ready for the upstream solutioin.  A possible hotfix would be to bypass nss_compat_ossl and call SSL_SetURL() from NSS directly.  The NSS default cert verification callback should then take care of the hostname validation.  But first I need to make sure that the NSS default cert verification callback is actually used by ELinks.

--- Additional comment from Kamil Dudka on 2013-02-13 17:01:55 CET ---

(In reply to comment #6)
> nss_compat_ossl does not seem to be ready for the upstream solutioin.  A
> possible hotfix would be to bypass nss_compat_ossl and call SSL_SetURL()
> from NSS directly.  The NSS default cert verification callback should then
> take care of the hostname validation.  But first I need to make sure that
> the NSS default cert verification callback is actually used by ELinks.

I have checked the sources of nss_compat_ossl and it explicitly ignores the hostname mismatch error:

    err = PORT_GetError();

    switch (err) {
    case SEC_ERROR_CERT_VALID:
    case SSL_ERROR_BAD_CERT_DOMAIN: /* We don't set set the hostname so we can
                                     * safely ignore this. In OpenSSL the
                                     * caller is responsible. */
        err = X509_V_OK;
        break;

Consequently, calling SSL_SetURL() has no effect anyway.
Comment 1 Kamil Dudka 2013-02-13 11:13:34 EST
How can one verify the certificate hostname without <openssl/asn1.h>?

Will nss_compat_ossl wrap the ASN1 decoder provided by NSS?
Comment 2 Fedora End Of Life 2013-07-04 01:25:39 EDT
This message is a reminder that Fedora 17 is nearing its end of life.
Approximately 4 (four) weeks from now Fedora will stop maintaining
and issuing updates for Fedora 17. It is Fedora's policy to close all
bug reports from releases that are no longer maintained. At that time
this bug will be closed as WONTFIX if it remains open with a Fedora 
'version' of '17'.

Package Maintainer: If you wish for this bug to remain open because you
plan to fix it in a currently maintained version, simply change the 'version' 
to a later Fedora version prior to Fedora 17's end of life.

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would still like  to see this bug fixed and are able to reproduce it 
against a later version  of Fedora, you are encouraged  change the 
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Comment 3 Matthew Harmsen 2013-09-16 17:08:47 EDT
Kamil,

Looking at the "elink" OpenSSL code used to provide a subject name validity check as described in:

    Bugzilla Bug #881411 - elinks/links: does not properly verify SSL 
                           certificates

It appears that they may be hanging on the call "ASN1_STRING_to_UTF8()" call which is NOT provided by "nss_compat_ossl".

However, upon a closer review of the "elink" OpenSSL code used to provide a subject name validity check, it appears that there were numerous other calls that are not currently provided by "nss_compat_ossl" including:

    * V_ASN1_OCTET_STRING
    * GENERAL_NAMES
    * X509_STORE_CTX_get_error_depth()
    * X509_NAME_ENTRY
    * X509_NAME_get_index_by_NID()
    * X509_NAME_get_entry()
    * X509_NAME_ENTRY_get_data()

In the initial comment above, you had suggested that a workaround for this issue might be to utilize a direct call to NSS via SSL_SetURL(), but then added that this would not work due to the default error code handler provided by "nss_compat_ossl" (note that it may be reasonable for some applications to allow a subject name validity mismatch).  Although not ideal, could it be possibly suggested to use SSL_SetURL() without using the default error code handler provided by "nss_compat_ossl" (e. g. - registry of an alternative error code handler) instead?

I realize that this somewhat defeats the purpose of having a compatibility library, but as there is currently no specific timeline on when/if these calls would be supported by "nss_compat_ossl", this may be a more timely solution for the elinks project.
Comment 4 Kamil Dudka 2013-09-17 04:26:33 EDT
(In reply to Matthew Harmsen from comment #3)
> I realize that this somewhat defeats the purpose of having a compatibility
> library, but as there is currently no specific timeline on when/if these
> calls would be supported by "nss_compat_ossl", this may be a more timely
> solution for the elinks project.

The problem is that the vast majority of (potential?) clients of nss_compat_ossl need to verify the hostname as elinks does.  Are all of them supposed to bypass the compatibility layer and use the NSS API directly in order not to have security issues?
Comment 6 Florian Weimer 2013-09-17 06:10:23 EDT
(In reply to Kamil Dudka from comment #4)
> (In reply to Matthew Harmsen from comment #3)
> > I realize that this somewhat defeats the purpose of having a compatibility
> > library, but as there is currently no specific timeline on when/if these
> > calls would be supported by "nss_compat_ossl", this may be a more timely
> > solution for the elinks project.
> 
> The problem is that the vast majority of (potential?) clients of
> nss_compat_ossl need to verify the hostname as elinks does.  Are all of them
> supposed to bypass the compatibility layer and use the NSS API directly in
> order not to have security issues?

I think this is impossible to fix until OpenSSL gets its own host name validation function.  X509_check_host will be part of the next release, but it won't help until it's actually used by client code.

At present, code that reimplements X509_check_host uses difficult-to-predict parts of the OpenSSL ASN.1 and X.509 support routines, and it doesn't make much sense to support all of that in a compatibility wrapper.
Comment 7 Kamil Dudka 2013-09-18 07:55:00 EDT
Anybody feels like doing a review of attachment #799344 [details]?  Thanks in advance!
Comment 8 pjp 2014-12-03 13:22:59 EST
Hello mharmsen,

Could you please fix this soon?
Comment 9 Matthew Harmsen 2014-12-08 18:46:32 EST
(In reply to pjp from comment #8)
> Hello mharmsen,
> 
> Could you please fix this soon?

Unfortunately, there are no current plans to address the issues outlined in this bug.

As always, we welcome patches!

-- Matt
Comment 10 pjp 2015-04-09 13:32:01 EDT
Hello mharmsen@redhat.com,

You plan to fix this soon?
Comment 11 Florian Weimer 2015-04-09 13:36:36 EDT
This is impossible to fix.  nss_compat_ossl is terminally broken and should be retired.  Its few reverse dependencies can just use OpenSSL instead.
Comment 12 Kamil Dudka 2015-04-09 16:04:11 EDT
ELinks is already switched to use OpenSSL in rawhide:

http://pkgs.fedoraproject.org/cgit/elinks.git/commit/?id=6e8e7242

In stable Fedora, there is a workaround for this bug:

http://pkgs.fedoraproject.org/cgit/elinks.git/commit/?id=8ceec5fa
Comment 13 Fedora Admin XMLRPC Client 2015-04-29 18:36:03 EDT
This package has changed ownership in the Fedora Package Database.  Reassigning to the new owner of this component.
Comment 14 Fedora Admin XMLRPC Client 2015-05-26 07:03:15 EDT
This package has changed ownership in the Fedora Package Database.  Reassigning to the new owner of this component.
Comment 15 Fedora Admin XMLRPC Client 2015-05-26 07:26:54 EDT
This package has changed ownership in the Fedora Package Database.  Reassigning to the new owner of this component.
Comment 16 Fedora Admin XMLRPC Client 2015-05-26 11:33:10 EDT
This package has changed ownership in the Fedora Package Database.  Reassigning to the new owner of this component.
Comment 17 Jan Kurik 2015-07-15 10:51:43 EDT
This bug appears to have been reported against 'rawhide' during the Fedora 23 development cycle.
Changing version to '23'.

(As we did not run this process for some time, it could affect also pre-Fedora 23 development
cycle bugs. We are very sorry. It will help us with cleanup during Fedora 23 End Of Life. Thank you.)

More information and reason for this action is here:
https://fedoraproject.org/wiki/BugZappers/HouseKeeping/Fedora23