--- pam_ssh-1.92.orig/pam_get_pass.c	2004-02-19 19:59:05.000000000 +0100
+++ pam_ssh-1.92/pam_get_pass.c	2009-04-18 13:51:10.000000000 +0200
@@ -63,6 +63,8 @@
 	retval = conv->conv(1, msgs, &resp, conv->appdata_ptr);
 	if (retval != PAM_SUCCESS)
 		return retval;
+	if (resp[0].resp == NULL)
+		return PAM_AUTHTOK_RECOVERY_ERR;
 	retval = pam_set_item(pamh, PAM_AUTHTOK, resp[0].resp);
 	if (retval != PAM_SUCCESS)
 		return retval;