def load_host_keys(filename):
from ssh.hostkeys import HostKeys<EOL>return HostKeys(filename)<EOL>
Read a file of known SSH host keys, in the format used by openssh, and
return a compound dict of C{hostname -> keytype ->} L{PKey <ssh.pkey.PKey>}.
The hostname may be an IP address or DNS name.  The keytype will be either
C{"ssh-rsa"} or C{"ssh-dss"}.

This type of file unfortunately doesn't exist on Windows, but on posix,
it will usually be stored in C{os.path.expanduser("~/.ssh/known_hosts")}.

Since 1.5.3, this is just a wrapper around L{HostKeys}.

@param filename: name of the file to read host keys from
@type filename: str
@return: dict of host keys, indexed by hostname and then keytype
@rtype: dict(hostname, dict(keytype, L{PKey <ssh.pkey.PKey>}))