Getting error on "data-ciphers" line on OVPN client

jimp

You shouldn't blindly include all the AES algorithms. Stick to the GCM and CBCs. Most likely explanation is that your client platform doesn't support one or more of the ciphers.

The client export generates OpenVPN 2.5 configs because it exports OpenVPN 2.5 installers, so that's probably OK (provided your client platform is running OpenVPN 2.5...)

Your log message does say your client is OpenVPN 2.4.9, though, so you probably do need to update the client to one that uses OpenVPN 2.5.0 or tick the Legacy box and export again.

dirtyfreebooter

yea, the error message said,

... config.ovpn:4: data-ciphers (2.4.9)

so I assumed his client was 2.4.9 and not 2.5, but yea, that is a lot of ciphers as well to enable... yea, easiest just to stick GCM/CBC like @jimp said

PCOL IT Admin

Thanks for the help, folks!

I upgraded Tunnelblick to 3.8.5beta01 (build 5610), which has OpenVPN 2.5 (also had to set "OpenVPN version" drop in Settings to "Latest", which is OpenVPN 2.5.0 w/ OpenSSL 1.1.1h)

Also edited my client config, it is now:

dev tun
persist-tun
persist-key
data-ciphers AES-128-CBC:AES-192-CBC:AES-192-CFB:AES-192-OFB:AES-256-CBC:AES-256-CFB:AES-256-OFB
data-ciphers-fallback AES-128-CBC
auth SHA256
tls-client
client
resolv-retry infinite
remote vpn-gw.mycompany.com 1194 udp4
verify-x509-name "vpn-gw.mycompany.com" name
auth-user-pass
remote-cert-tls server

Now I do get connected, but I do not have a route to the remote LAN, just one for the VPN network itself (local LAN is 192.168.100.0/24, OVPN network is 192.168.5.0/24, and remote LAN is 192.168.10.0/24):

mymac:~ me$ netstat -nr -f inet | grep -v -e I -e "/32"
Routing tables

Destination        Gateway            Flags        Netif Expire
default            192.168.100.1      UGSc           en0
127                127.0.0.1          UCS            lo0
127.0.0.1          127.0.0.1          UH             lo0
169.254            link#4             UCS            en0      !
192.168.5          192.168.5.2        UGSc         utun6
192.168.5.2        192.168.5.2        UH           utun6
192.168.100        link#4             UCS            en0      !
224.0.0/4          link#4             UmCS           en0      !

The end of the Tunnelblick log has:

                           13:05:17 *Tunnelblick:  Start of output from client.up.tunnelblick.sh
                           WARNING: $route_vpn_gateway is empty
                           13:05:19 *Tunnelblick:  NOTE: No network configuration changes need to be made.
                           13:05:19 *Tunnelblick:  WARNING: Will NOT monitor for other network configuration changes.
                           13:05:19 *Tunnelblick:  WARNING: Will NOT disable IPv6 settings.
                           13:05:19 *Tunnelblick:  DNS servers '192.168.100.1' will be used for DNS queries when the VPN is active
                           13:05:19 *Tunnelblick:  NOTE: The DNS servers do not include any free public DNS servers known to Tunnelblick. This may cause DNS queries to fail or be intercepted or falsified even if they are directed through the VPN. Specify only known public DNS servers or DNS servers located on the VPN network to avoid such problems.
                           13:05:19 *Tunnelblick:  Flushed the DNS cache via dscacheutil
                           13:05:19 *Tunnelblick:  /usr/sbin/discoveryutil not present. Not flushing the DNS cache via discoveryutil
                           13:05:19 *Tunnelblick:  Notified mDNSResponder that the DNS cache was flushed
                           13:05:19 *Tunnelblick:  Notified mDNSResponderHelper that the DNS cache was flushed
                           13:05:19 *Tunnelblick:  End of output from client.up.tunnelblick.sh
                           13:05:19 *Tunnelblick:  **********************************************
2020-11-24 13:05:19.792773 Initialization Sequence Completed
2020-11-24 13:05:19.792939 MANAGEMENT: >STATE:1606241119,CONNECTED,SUCCESS,192.168.5.2,71.xxx.xxx.xxx,1194,,
2020-11-24 13:05:21.018480 *Tunnelblick: Routing info stdout:
   route to: 192.168.100.1
destination: 192.168.100.1
  interface: en0
      flags: <UP,HOST,DONE,LLINFO,WASCLONED,IFSCOPE,IFREF,ROUTER>
 recvpipe  sendpipe  ssthresh  rtt,msec    rttvar  hopcount      mtu     expire
       0         0         0         0         0         0      1500      1116 
stderr:

2020-11-24 13:05:21.018824 *Tunnelblick: Warning: DNS server address 192.168.100.1 is not a public IP address and is not being routed through the VPN.


2020-11-24 13:05:26.193775 *Tunnelblick: This computer's apparent public IP address (71.zzz.zzz.zzz) was unchanged after the connection was made

So it seems I may be missing some needed entries yet on the pfSense (server) side? I made the OVPN config on pfSense via the wizard.

dirtyfreebooter

I know its 20 min long these days, but worth a watch and goes over all this settings, including routing to your local network: https://www.youtube.com/watch?v=PgielyUFGeQ

Are you probably missing server settings for IPv4 Local network(s) and IPv6 Local network(s)

olivluca

I'm having this problem even with the 2.5.0 client on windows.

2021-05-12 08:13:40 OpenVPN 2.5.0 x86_64-w64-mingw32 [SSL (OpenSSL)] [LZO] [LZ4] [PKCS11] [AEAD] built on Oct 28 2020
....
2021-05-12 08:13:54 OPTIONS ERROR: failed to negotiate cipher with server.  Add the server's cipher ('AES-128-CBC') to --data-ciphers (currently 'AES-128-GCM') if you want to connect to this server.

the generated ovpn file has

data-ciphers AES-128-GCM
data-ciphers-fallback AES-128-CBC

if I mark the "legacy client" option it changes to

cipher AES-128-CBC

and the client can connect.
It seems the client is ignoring the data-ciphers-fallback option.

Gertjan

Command line pfSense :

openvpn --help

The first line tells you that the latest pfSense (2.5.1) is using

OpenVPN 2.5.1 amd64-portbld-freebsd12.2 [SSL (OpenSSL)] [LZO] [LZ4] [MH/RECVDA] [AEAD] built on Apr  5 2021

I only export settings from pfSense, not the 'executable Windows OpenVPON Installer package', I download the latest OpebVPN client from OpenVPN (it's also open source).

Get it from here : https://openvpn.net/community-downloads/

Like pfSense, don't stay on "2.5.0". OpenVPN had issues to, so they went to 2.5.1 to stabilised, for now, on 2.5.2.
The 2.5.2 client works fine with the OpenVPN server 2.5.1 on pfSense.

Btw : It's just pure coincidence that OpenVPN uses nearly identical version numbers as the CE version of pfSense.

olivluca

@gertjan thank you, but for me and my users the all in one installer is more convenient. I didn't know that openvpn 2.5.0 had issues.

olivluca

@gertjan said in Getting error on "data-ciphers" line on OVPN client:

Get it from here : https://openvpn.net/community-downloads/

I just tried with the 2.5.2 openvpn client and it has the same problem:

Wed May 12 10:14:28 2021 OpenVPN 2.5.2 i686-w64-mingw32 [SSL (OpenSSL)] [LZO] [LZ4] [PKCS11] [AEAD] built on Apr 21 2021
....
Wed May 12 10:16:22 2021 OPTIONS ERROR: failed to negotiate cipher with server.  Add the server's cipher ('AES-128-CBC') to --data-ciphers (currently 'AES-128-GCM') if you want to connect to this server.

olivluca

maybe it's because I'm still with pfSense 2.4.5p1 that has openvpn 2.4.9 (I cannot upgrade to 2.5.1 due to its problems with NAT and multi WAN)

Gertjan

@olivluca said in Getting error on "data-ciphers" line on OVPN client:

openvpn 2.5.0 had issues.

As pfSEnse, they have a FAQ, manual, forum etc.
Yes, they have issues - like any other huge (OpenVPN is huge ....) (software) product.

The shift from 2.4.x to 2.5.x has special help pages, with all the details about these changes.

If you use OpenVPN, don't hesistate. Bookmark this one - and use it.

olivluca

@gertjan said in Getting error on "data-ciphers" line on OVPN client:

Yes, they have issues - like any other huge (OpenVPN is huge ....) (software) product.

Sure, but I didn't mean it like that, I was referring to the interaction with the "client export" generated settings. Anyway, the latest release of openvpn has the same problem.