add _krb5_get_ad

lib/krb5/ticket.c

@@ -322,6 +322,37 @@ out:
     return ret;
 }
 
+KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
+_krb5_get_ad(krb5_context context,
+	     const AuthorizationData *ad,
+	     krb5_keyblock *sessionkey,
+	     int type,
+	     krb5_data *data)
+{
+    krb5_boolean found = FALSE;
+    krb5_error_code ret;
+
+    krb5_data_zero(data);
+
+    if (ad == NULL) {
+	krb5_set_error_message(context, ENOENT,
+			       N_("No authorization data", ""));
+	return ENOENT; /* XXX */
+    }
+
+    ret = find_type_in_ad(context, type, data, &found, TRUE, sessionkey, ad, 0);
+    if (ret)
+	return ret;
+    if (!found) {
+	krb5_set_error_message(context, ENOENT,
+			       N_("Have no authorization data of type %d", ""),
+			       type);
+	return ENOENT; /* XXX */
+    }
+    return 0;
+}
+
+
 /**
  * Extract the authorization data type of type from the ticket. Store
  * the field in data. This function is to use for kerberos