OpenSSH 7.0 disables DSA keys by default


The road ahead was never bright for DSA keys and the writing was clear
on the wall. Ezeelogin SSH gateway will be dropping DSA keys and would 
be using ONLY RSA keys in future releases. 
Starting with the 7.0 release of OpenSSH, support for ssh-dss keys has
been disabled by  default at runtime due to their inherit weakness.If
you rely on these key types,you will have to take corrective action or 
risk being locked out. Your best option is to generate new keys 
using strong algos such as rsa or ecdsa or ed25519.RSA keys will give
you the greatest portability with other clients/servers while ed25519
will get you the best security with OpenSSH.(but requires recent versions of
client & server).

If you are stuck with DSA keys, you can re-enable support locally by updating
 your sshd_config and ~/.ssh/config files with lines like so: 
     PubkeyAcceptedKeyTypes=+ssh-dss

Be aware though that eventually OpenSSH will drop support for DSA keys entirely, 
so this is only a stop gap solution.

More details can be found on 
OpenSSH's website: http://www.openssh.com/legacy.html