auth_userchallenge
auth_session_t *auth_userchallenge(char *, char *, char *, char **);
DEF_WEAK(auth_userchallenge);
PROTO_NORMAL(auth_userchallenge);
if (!(as = auth_userchallenge(myname, login_style, "auth-doas",
authctxt->as = auth_userchallenge(authctxt->user,