Last Updated: 2015-06-01
Condition or Error
The following error is reported when trying to connect:
Error: could not settle on encryption_client algorithm
Causes
Can be due to missing an acceptable cipher on any one of the hosts.
Rectifications
This is a list of acceptable ciphers:
aes128-cbc 3des-cbc blowfish-cbc cast128-cbc aes192-cbc aes256-cbc rijndael-cbc@lysator.liu.se idea-cbc none arcfour128 arcfour256
These can be configured in
/etc/ssh/sshd_config
under Ciphers.
Try adding a supported cipher
(aes256-cbc_ to the end
of the ciphers in your ssh server config file. Note that SSH
and OpenSSL ciphers are mapped, for example like the
following:
// Maps the SSH name of a cipher to it's corresponding OpenSSL name
SSH_TO_OSSL = {
"3des-cbc" => "des-ede3-cbc",
"blowfish-cbc" => "bf-cbc",
"aes256-cbc" => "aes-256-cbc",
"aes192-cbc" => "aes-192-cbc",
"aes128-cbc" => "aes-128-cbc",
"idea-cbc" => "idea-cbc",
"cast128-cbc" => "cast-cbc",
"arcfour128" => "rc4",
"arcfour256" => "rc4",
"arcfour512" => "rc4",
"none" => "none"
}