From: Erik Kapfer <erik.kapfer@ipfire.org>
Date: Fri, 6 Oct 2017 13:14:48 +0000 (+0200)
Subject: OpenVPN: Fix for '--ns-cert-type server is deprecated' .
X-Git-Tag: v2.19-core115~42
X-Git-Url: http://git.ipfire.org/?p=ipfire-2.x.git;a=commitdiff_plain;h=b66b02ab73863bcb9130300d8ef0eecdc51efde3

OpenVPN: Fix for '--ns-cert-type server is deprecated' .

- Added extended key usage based on RFC3280 TLS rules for OpenVPNs OpenSSL configuration,
so '--remote-cert-tls' can be used instead of the old and deprecated '--ns-cert-type'
if the host certificate are newely generated with this options.
Nevertheless both directives (old and new) will work also with old CAs.

- Automatic detection if the host certificate uses the new options.
If it does, '--remote-cert-tls server' will be automatically set into the client
configuration files for Net-to-Net and Roadwarriors connections.

If it does NOT, the old '--ns-cert-type server' directive will be set in the client
configuration file.

Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>
---

diff --git a/config/ovpn/openssl/ovpn.cnf b/config/ovpn/openssl/ovpn.cnf
index ab026c1095..40daf2a0a8 100644
--- a/config/ovpn/openssl/ovpn.cnf
+++ b/config/ovpn/openssl/ovpn.cnf
@@ -77,6 +77,8 @@ basicConstraints		= CA:FALSE
 nsComment			= "OpenSSL Generated Certificate"
 subjectKeyIdentifier		= hash
 authorityKeyIdentifier		= keyid,issuer:always
+extendedKeyUsage               = clientAuth
+keyUsage                       = digitalSignature
 
 [ server ]
 
@@ -86,6 +88,8 @@ nsCertType			= server
 nsComment			= "OpenSSL Generated Server Certificate"
 subjectKeyIdentifier		= hash
 authorityKeyIdentifier		= keyid,issuer:always 
+extendedKeyUsage               = serverAuth
+keyUsage                       = digitalSignature, keyEncipherment
 
 [ v3_req ]
 basicConstraints 		= CA:FALSE
diff --git a/html/cgi-bin/ovpnmain.cgi b/html/cgi-bin/ovpnmain.cgi
index d46a14e791..ceb88c1569 100644
--- a/html/cgi-bin/ovpnmain.cgi
+++ b/html/cgi-bin/ovpnmain.cgi
@@ -1061,8 +1061,15 @@ unless(-d "${General::swroot}/ovpn/n2nconf/$cgiparams{'NAME'}"){mkdir "${General
 		}
         }
   }
- 
-  print CLIENTCONF "ns-cert-type server\n";   
+  # Check host certificate if X509 is RFC3280 compliant.
+  # If not, old --ns-cert-type directive will be used.
+  # If appropriate key usage extension exists, new --remote-cert-tls directive will be used.
+  my $hostcert = `/usr/bin/openssl x509 -text -in ${General::swroot}/ovpn/certs/servercert.pem`;
+  if ($hostcert !~ /TLS Web Server Authentication/) {
+       print CLIENTCONF "ns-cert-type server\n";
+  } else {
+       print CLIENTCONF "remote-cert-tls server\n";
+  }
   print CLIENTCONF "# Auth. Client\n"; 
   print CLIENTCONF "tls-client\n"; 
   print CLIENTCONF "# Cipher\n"; 
@@ -2173,7 +2180,15 @@ if ($confighash{$cgiparams{'KEY'}}[3] eq 'net'){
 		}
 	}
    }
-   print CLIENTCONF "ns-cert-type server\n";   
+   # Check host certificate if X509 is RFC3280 compliant.
+   # If not, old --ns-cert-type directive will be used.
+   # If appropriate key usage extension exists, new --remote-cert-tls directive will be used.
+   my $hostcert = `/usr/bin/openssl x509 -text -in ${General::swroot}/ovpn/certs/servercert.pem`;
+   if ($hostcert !~ /TLS Web Server Authentication/) {
+               print CLIENTCONF "ns-cert-type server\n";
+   } else {
+               print CLIENTCONF "remote-cert-tls server\n";
+   }
    print CLIENTCONF "# Auth. Client\n"; 
    print CLIENTCONF "tls-client\n"; 
    print CLIENTCONF "# Cipher\n";
@@ -2332,7 +2347,15 @@ else
         print CLIENTCONF "comp-lzo\r\n";
     }
     print CLIENTCONF "verb 3\r\n";
-    print CLIENTCONF "ns-cert-type server\r\n";
+	# Check host certificate if X509 is RFC3280 compliant.
+	# If not, old --ns-cert-type directive will be used.
+	# If appropriate key usage extension exists, new --remote-cert-tls directive will be used.
+	my $hostcert = `/usr/bin/openssl x509 -text -in ${General::swroot}/ovpn/certs/servercert.pem`;
+	if ($hostcert !~ /TLS Web Server Authentication/) {
+		print CLIENTCONF "ns-cert-type server\r\n";
+	} else {
+		print CLIENTCONF "remote-cert-tls server\r\n";
+	}
     print CLIENTCONF "verify-x509-name $vpnsettings{ROOTCERT_HOSTNAME} name\r\n";
     if ($vpnsettings{MSSFIX} eq 'on') {
 	print CLIENTCONF "mssfix\r\n";