Bug 1504016 - strongswan uses wrong (default) path for system-wide certificates
Summary: strongswan uses wrong (default) path for system-wide certificates
Keywords:
Status: CLOSED EOL
Alias: None
Product: Fedora
Classification: Fedora
Component: strongswan
Version: 27
Hardware: Unspecified
OS: Unspecified
unspecified
unspecified
Target Milestone: ---
Assignee: Pavel Šimerda
QA Contact: Fedora Extras Quality Assurance
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2017-10-19 10:01 UTC by Ed Marshall
Modified: 2018-11-30 21:45 UTC (History)
5 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed: 2018-11-30 21:45:13 UTC
Type: Bug
Embargoed:


Attachments (Terms of Use)

Description Ed Marshall 2017-10-19 10:01:28 UTC
At build-time, strongswan isn't compiled with --with-nm-ca-dir set to the system-wide PKI store, which causes problems when configured via NetworkManager without a certificate specified.

Taking a peek at Debian, it looks like they ran into the same issue: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=835095

This can be tweaked without rebuilding by end-users by creating /etc/strongswan/strongswan.d/charon-nm.conf:

charon-nm {
    ca_dir = /etc/pki/tls/certs
}

Note that once you make this change, you run into selinux policy issues; charon-nm isn't allowed to access those files:

AVC avc:  denied  { map } for  pid=31942 comm="charon-nm" path="/etc/pki/ca-trust/extracted/pem/tls-ca-bundle.pem" dev="dm-1" ino=394791 scontext=system_u:system_r:ipsec_t:s0 tcontext=system_u:object_r:cert_t:s0 tclass=file permissive=0
AVC avc:  denied  { map } for  pid=31942 comm="charon-nm" path="/etc/pki/ca-trust/extracted/openssl/ca-bundle.trust.crt" dev="dm-1" ino=394787 scontext=system_u:system_r:ipsec_t:s0 tcontext=system_u:object_r:cert_t:s0 tclass=file permissive=0

Comment 1 Mikhail Zabaluev 2018-05-22 12:53:36 UTC
Access to the certificates worked for me in Fedora 28.

The package fix to use --with-nm-ca-dir configure option would be a better solution. I have tested it locally and will send a PR soon.

Comment 2 Mikhail Zabaluev 2018-05-22 17:22:05 UTC
Proposed fix: https://src.fedoraproject.org/rpms/strongswan/pull-request/6

Comment 3 Paul Wouters 2018-05-23 20:18:38 UTC
Why would you want the system CA store that relates to public CA's for TLS to apply to your VPN CA's ? almost always, VPN CA's are private CA's. I wouldn't want to add 500+ CA's to my VPN server setup.

Comment 4 Mikhail Zabaluev 2018-05-24 05:47:14 UTC
(In reply to Paul Wouters from comment #3)
> Why would you want the system CA store that relates to public CA's for TLS
> to apply to your VPN CA's ? almost always, VPN CA's are private CA's. I
> wouldn't want to add 500+ CA's to my VPN server setup.

The configure flag only applies to charon-nm; the CAs are used to authenticate the server on the initiator side. As mentioned in comment #0, this is easily overridable in charon-nm settings.

Apparently, strongSwan developers think nothing bad of using /usr/share/ca-certificates (Debian's trusted vendor CA directory?) as the default. It should work out of the box when the VPN server does use a certificate issued by a private CA, which many do (it does not have to be the same CA that is used for client auth PKI, which indeed is often private to the server operator). Adding a self-signed CA to /etc/pki/ca-trusted anchors is also very easy; conversely, supplying a custom certificate in the UI does not currently work (https://wiki.strongswan.org/issues/2671). If there is a concern with the trust anchors in /etc/pki/ca-trusted, it should equally apply to any applications using the system-wide certificate store, not just VPN.

Comment 5 Mikhail Zabaluev 2018-05-24 05:55:30 UTC
(In reply to Mikhail Zabaluev from comment #4)
> It should work out of the box when the VPN server does use a
> certificate issued by a private CA, which many do

That should have been "public CA", sorry.

Comment 6 Paul Wouters 2018-05-25 16:21:41 UTC
I don't agree with this assessment. Anyone can get a server cert signed by a random CA. So if someone spoofs DNS of your corporate VPN server, you don't want it to get validated when someone redirects you to their bogus VPN server that you validate with a random public CA. Obviously, they would just accept your client AUTH regardless and now you think you are connected to your VPN while you are connected to some rogue server.

A VPN connection is quite different from a HTTPS connection. You have no reason to trust any HTTPS server. You have a trust relationship with your VPN service and allow them to do things, possibly even reconfigure your local network. But even just connected to them, might open up all yours ports via the VPN to the rogue server

Comment 7 Mikhail Zabaluev 2018-05-26 04:47:32 UTC
(In reply to Paul Wouters from comment #6)

I see your point. But the current default still makes no sense: /usr/share/ca-certificates does not exist in a typical Fedora installation and may be immutable in ostree-based setups.

Maybe point it to something like /etc/pki/vpn by default, and maybe later someone finds a clever managed way to populate it?

Comment 8 Mikhail Zabaluev 2018-05-28 06:26:17 UTC
New proposed fix: https://src.fedoraproject.org/rpms/strongswan/pull-request/7

Comment 9 Ben Cotton 2018-11-27 15:36:02 UTC
This message is a reminder that Fedora 27 is nearing its end of life.
On 2018-Nov-30  Fedora will stop maintaining and issuing updates for
Fedora 27. 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
EOL if it remains open with a Fedora  'version' of '27'.

Package Maintainer: If you wish for this bug to remain open because you
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Comment 10 Ben Cotton 2018-11-30 21:45:13 UTC
Fedora 27 changed to end-of-life (EOL) status on 2018-11-30. Fedora 27 is
no longer maintained, which means that it will not receive any further
security or bug fix updates. As a result we are closing this bug.

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