/*
 * validator/val_nsec.h - validator NSEC denial of existance functions.
 *
 * Copyright (c) 2007, NLnet Labs. All rights reserved.
 *
 * This software is open source.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 
 * Redistributions of source code must retain the above copyright notice,
 * this list of conditions and the following disclaimer.
 * 
 * Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 * 
 * Neither the name of the NLNET LABS nor the names of its contributors may
 * be used to endorse or promote products derived from this software without
 * specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

/**
 * \file
 *
 * This file contains helper functions for the validator module.
 * The functions help with NSEC checking, the different NSEC proofs
 * for denial of existance, and proofs for presence of types.
 */

#ifndef VALIDATOR_VAL_NSEC_H
#define VALIDATOR_VAL_NSEC_H
struct val_env;
struct module_env;
struct ub_packed_rrset_key;
enum sec_status;
struct reply_info;
struct query_info;
struct key_entry_key;

/**
 * Check DS absence.
 * There is a NODATA reply to a DS that needs checking.
 * NSECs can prove this is not a delegation point, or sucessfully prove
 * that there is no DS. Or this fails.
 *
 * @param env: module env for rrsig verification routines.
 * @param ve: validator env for rrsig verification routines.
 * @param qinfo: the DS queried for.
 * @param rep: reply received.
 * @param kkey: key entry to use for verification of signatures.
 * @param proof_ttl: if secure, the TTL of how long this proof lasts.
 * @return security status.
 *	SECURE: proved absence of DS.
 *	INSECURE: proved that this was not a delegation point.
 *	BOGUS: crypto bad, or no absence of DS proven. 
 *	UNCHECKED: there was no way to prove anything (no NSECs, unknown algo).
 */
enum sec_status val_nsec_prove_nodata_dsreply(struct module_env* env,
	struct val_env* ve, struct query_info* qinfo, 
	struct reply_info* rep, struct key_entry_key* kkey,
	uint32_t* proof_ttl);

/** Unit test call to test function for nsec typemap check */
int unitest_nsec_has_type_rdata(char* bitmap, size_t len, uint16_t type);

/**
 * Determine if a NSEC proves the NOERROR/NODATA conditions. This will also
 * handle the empty non-terminal (ENT) case and partially handle the
 * wildcard case. If the ownername of 'nsec' is a wildcard, the validator
 * must still be provided proof that qname did not directly exist and that
 * the wildcard is, in fact, *.closest_encloser.
 *
 * @param nsec: the nsec record to check against.
 * @param qinfo: the query info.
 * @return true if NSEC proves this.
 */
int nsec_proves_nodata(struct ub_packed_rrset_key* nsec, 
	struct query_info* qinfo);

#endif /* VALIDATOR_VAL_NSEC_H */