init_ctx
.opt.argfunc = init_ctx,
static int init_ctx(char *keyfile);
void* (*init_ctx)(Authctxt*);
if ((kbdintctxt->ctxt = kbdintctxt->device->init_ctx(authctxt)) == NULL) {
sshpam_ctxt = (sshpam_device.init_ctx)(authctxt);