Import ssh dsa keys to ROS

I gen dsa keys with puttygen.exe, this tool can save it with formats of OpenSSH and ssh.com
But MT during import any of this key tell my, that passphrase to key is wrong. But passphrase can’t be wrong! Other tools accept this pwd with generated key.

How i can gen dsa, that MT accepts, without installing any *nix systems? (sidelong glance toward mt wiki)