ssh works well but when you try to copy a file via scp you get this error

no hostkey alg

Go on your server and check if you have /etc/ssh/ssh_host_rsa_key and /etc/ssh/ssh_host_dsa_key files, if not, generate them

ssh-keygen -t rsa -f /etc/ssh/ssh_host_rsa_key
ssh-keygen -t dsa -f /etc/ssh/ssh_host_dsa_key