int libssh2_agent_get_identity(LIBSSH2_AGENT *agent,
struct libssh2_agent_publickey **store,
struct libssh2_agent_publickey *prev);
DESCRIPTION
libssh2_agent_get_identity(3) allows an application to iterate
over all public keys in the collection managed by ssh-agent.
store should point to a pointer that gets filled in to point to the
public key data.
prev is a pointer to a previous 'struct libssh2_agent_publickey'
as returned by a previous invoke of this function, or NULL to get the
first entry in the internal collection.
RETURN VALUE
Returns 0 if everything is fine and information about a host was stored in
the store struct.