On 6/2/22 12:57, Ron Yorston wrote:
Today OpenVPN was updated from 2.5.6-1 to 2.5.7-1 and my VPN
connection
broke. The log says:
nm-openvpn[8655]: --cipher is not set. Previous OpenVPN version defaulted to BF-CBC as
fallback when cipher negotiation failed in this case. If you need this fallback please add
'--data-ciphers-fallback BF-CBC' to your configuration and/or add BF-CBC to
--data-ciphers.
nm-openvpn[8655]: OpenVPN 2.5.7 x86_64-redhat-linux-gnu [SSL (OpenSSL)] [LZO] [LZ4]
[EPOLL] [PKCS11] [MH/PKTINFO] [AEAD] built on May 31 2022
nm-openvpn[8655]: library versions: OpenSSL 3.0.2 15 Mar 2022, LZO 2.10
nm-openvpn[8655]: NOTE: the current --script-security setting may allow this
configuration to call user-defined scripts
nm-openvpn[8655]: Cipher BF-CBC not supported
nm-openvpn[8655]: Exiting due to fatal error
2.5.6-1 says almost exactly the same, apart from the last two lines,
and doesn't break.
Adding 'cipher=AES-256-GCM' to the NetworkManager keyfile for the
VPN got it working again. The advice about 'data-ciphers-fallback'
and 'data-ciphers' is bogus because NetworkManager doesn't know about
those options.
Happened to me too.
Apparently it is a fight between "let's have a default that works"
and "let's not weaken security too easily".
https://community.openvpn.net/openvpn/wiki/CipherNegotiation
Regards.
--
Roberto Ragusa mail at robertoragusa.it