vpnmain.cgi: set SubjectAlternativeName default during root certificate generation

Some IPsec implementations such as OpenIKED require SubjectAlternativeName
data on certificates and refuse to establish connections otherwise.

The StrongSwan project also recommends it (see:
https://wiki.strongswan.org/projects/strongswan/wiki/SimpleCA) although
it is currently not enforced by their IPsec software.

For convenience purposes and to raise awareness, this patch adds a default
SubjectAlternativeName based on the machines hostname or IP address. Existing
certificates remain unchanged for obvious reasons.

The third version of this patch fixes a duplicate DNS query reported by Michael.

Fixes #11594

Signed-off-by: Peter Müller <peter.mueller@ipfire.org>
Cc: Michael Tremer <michael.tremer@ipfire.org>
Signed-off-by: Arne Fitzenreiter <arne_f@ipfire.org>

diff --git a/html/cgi-bin/vpnmain.cgi b/html/cgi-bin/vpnmain.cgi
index 33b504bc9b710170eb449f8f13babb03927e0f20..43cdc5aa04386bc9b065a80c7684f7cfac55f85d 100644 (file)
--- a/html/cgi-bin/vpnmain.cgi
+++ b/html/cgi-bin/vpnmain.cgi
@@ -2,7 +2,7 @@
 ###############################################################################
 #                                                                             #
 # IPFire.org - A linux based firewall                                         #
-# Copyright (C) 2007-2019  IPFire Team  info@ipfire.org                       #
+# Copyright (C) 2007-2020  IPFire Team  <info@ipfire.org>                     #
 #                                                                             #
 # This program is free software: you can redistribute it and/or modify        #
 # it under the terms of the GNU General Public License as published by        #
@@ -822,8 +822,10 @@ END
                        close IPADDR;
                        chomp ($ipaddr);
                        $cgiparams{'ROOTCERT_HOSTNAME'} = (gethostbyaddr(pack("C4", split(/\./, $ipaddr)), 2))[0];
+                       $cgiparams{'SUBJECTALTNAME'} = "DNS:" . $cgiparams{'ROOTCERT_HOSTNAME'};
                        if ($cgiparams{'ROOTCERT_HOSTNAME'} eq '') {
                                $cgiparams{'ROOTCERT_HOSTNAME'} = $ipaddr;
+                               $cgiparams{'SUBJECTALTNAME'} = "IP:" . $cgiparams{'ROOTCERT_HOSTNAME'};
                        }
                }
                $cgiparams{'ROOTCERT_COUNTRY'} = $vpnsettings{'ROOTCERT_COUNTRY'} if (!$cgiparams{'ROOTCERT_COUNTRY'});
@@ -975,6 +977,11 @@ END
                #       IP: an IP address
                # example: email:franck@foo.com,IP:10.0.0.10,DNS:franck.foo.com
 
+               if ($cgiparams{'SUBJECTALTNAME'} eq '') {
+                       $errormessage = $Lang::tr{'vpn subjectaltname missing'};
+                       goto ROOTCERT_ERROR;
+               }
+
                if ($cgiparams{'SUBJECTALTNAME'} ne '' && $cgiparams{'SUBJECTALTNAME'} !~ /^(email|URI|DNS|RID|IP):[a-zA-Z0-9 :\/,\.\-_@]*$/) {
                        $errormessage = $Lang::tr{'vpn altname syntax'};
                        goto VPNCONF_ERROR;
@@ -1129,7 +1136,7 @@ END
        }
        print <<END
                </select></td></tr>
-       <tr><td class='base'>$Lang::tr{'vpn subjectaltname'} (subjectAltName=email:*,URI:*,DNS:*,RID:*)</td>
+       <tr><td class='base'>$Lang::tr{'vpn subjectaltname'} (subjectAltName=email:*,URI:*,DNS:*,RID:*)&nbsp;<img src='/blob.gif' alt='*' /></td>
        <td class='base' nowrap='nowrap'><input type='text' name='SUBJECTALTNAME' value='$cgiparams{'SUBJECTALTNAME'}' size='32' /></td></tr>
        <tr><td>&nbsp;</td>
                <td><br /><input type='submit' name='ACTION' value='$Lang::tr{'generate root/host certificates'}' /><br /><br /></td></tr>