val_nsec.h revision 269257 
1/*
2 * validator/val_nsec.h - validator NSEC denial of existance functions.
3 *
4 * Copyright (c) 2007, NLnet Labs. All rights reserved.
5 *
6 * This software is open source.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 *
12 * Redistributions of source code must retain the above copyright notice,
13 * this list of conditions and the following disclaimer.
14 *
15 * Redistributions in binary form must reproduce the above copyright notice,
16 * this list of conditions and the following disclaimer in the documentation
17 * and/or other materials provided with the distribution.
18 *
19 * Neither the name of the NLNET LABS nor the names of its contributors may
20 * be used to endorse or promote products derived from this software without
21 * specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
24 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
25 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
26 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
27 * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
28 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
29 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
30 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
31 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
32 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
33 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
34 */
35
36/**
37 * \file
38 *
39 * This file contains helper functions for the validator module.
40 * The functions help with NSEC checking, the different NSEC proofs
41 * for denial of existance, and proofs for presence of types.
42 */
43
44#ifndef VALIDATOR_VAL_NSEC_H
45#define VALIDATOR_VAL_NSEC_H
46#include "util/data/packed_rrset.h"
47struct val_env;
48struct module_env;
49struct ub_packed_rrset_key;
50struct reply_info;
51struct query_info;
52struct key_entry_key;
53
54/**
55 * Check DS absence.
56 * There is a NODATA reply to a DS that needs checking.
57 * NSECs can prove this is not a delegation point, or sucessfully prove
58 * that there is no DS. Or this fails.
59 *
60 * @param env: module env for rrsig verification routines.
61 * @param ve: validator env for rrsig verification routines.
62 * @param qinfo: the DS queried for.
63 * @param rep: reply received.
64 * @param kkey: key entry to use for verification of signatures.
65 * @param proof_ttl: if secure, the TTL of how long this proof lasts.
66 * @param reason: string explaining why bogus.
67 * @return security status.
68 *	SECURE: proved absence of DS.
69 *	INSECURE: proved that this was not a delegation point.
70 *	BOGUS: crypto bad, or no absence of DS proven.
71 *	UNCHECKED: there was no way to prove anything (no NSECs, unknown algo).
72 */
73enum sec_status val_nsec_prove_nodata_dsreply(struct module_env* env,
74	struct val_env* ve, struct query_info* qinfo,
75	struct reply_info* rep, struct key_entry_key* kkey,
76	time_t* proof_ttl, char** reason);
77
78/**
79 * nsec typemap check, takes an NSEC-type bitmap as argument, checks for type.
80 * @param bitmap: pointer to the bitmap part of wireformat rdata.
81 * @param len: length of the bitmap, in bytes.
82 * @param type: the type (in host order) to check for.
83 * @return true if the type bit was set in the bitmap. false if not, or
84 * 	if the bitmap was malformed in some way.
85 */
86int nsecbitmap_has_type_rdata(uint8_t* bitmap, size_t len, uint16_t type);
87
88/**
89 * Check if type is present in the NSEC typemap
90 * @param nsec: the nsec RRset.
91 *	If there are multiple RRs, then each must have the same typemap,
92 *	since the typemap represents the types at this domain node.
93 * @param type: type to check for, host order.
94 * @return true if present
95 */
96int nsec_has_type(struct ub_packed_rrset_key* nsec, uint16_t type);
97
98/**
99 * Determine if a NSEC proves the NOERROR/NODATA conditions. This will also
100 * handle the empty non-terminal (ENT) case and partially handle the
101 * wildcard case. If the ownername of 'nsec' is a wildcard, the validator
102 * must still be provided proof that qname did not directly exist and that
103 * the wildcard is, in fact, *.closest_encloser.
104 *
105 * @param nsec: the nsec record to check against.
106 * @param qinfo: the query info.
107 * @param wc: if the nodata is proven for a wildcard match, the wildcard
108 * 	closest encloser is returned, else NULL (wc is unchanged).
109 * 	This closest encloser must then match the nameerror given for the
110 * 	nextcloser of qname.
111 * @return true if NSEC proves this.
112 */
113int nsec_proves_nodata(struct ub_packed_rrset_key* nsec,
114	struct query_info* qinfo, uint8_t** wc);
115
116/**
117 * Determine if the given NSEC proves a NameError (NXDOMAIN) for a given
118 * qname.
119 *
120 * @param nsec: the nsec to check
121 * @param qname: what was queried.
122 * @return true if proven.
123 */
124int val_nsec_proves_name_error(struct ub_packed_rrset_key* nsec,
125	uint8_t* qname);
126
127/**
128 * Determine if the given NSEC proves a positive wildcard response.
129 * @param nsec: the nsec to check
130 * @param qinf: what was queried.
131 * @param wc: wildcard (without *. label)
132 * @return true if proven.
133 */
134int val_nsec_proves_positive_wildcard(struct ub_packed_rrset_key* nsec,
135	struct query_info* qinf, uint8_t* wc);
136
137/**
138 * Determine closest encloser of a query name and the NSEC that covers it
139 * (and thus disproved it).
140 * A name error must have been proven already, otherwise this will be invalid.
141 * @param qname: the name queried for.
142 * @param nsec: the nsec RRset.
143 * @return closest encloser dname or NULL on error (bad nsec RRset).
144 */
145uint8_t* nsec_closest_encloser(uint8_t* qname,
146	struct ub_packed_rrset_key* nsec);
147
148/**
149 * Determine if the given NSEC proves that a wildcard match does not exist.
150 *
151 * @param nsec: the nsec RRset.
152 * @param qname: the name queried for.
153 * @param qnamelen: length of qname.
154 * @return true if proven.
155 */
156int val_nsec_proves_no_wc(struct ub_packed_rrset_key* nsec, uint8_t* qname,
157	size_t qnamelen);
158
159/**
160 * Determine the DLV result, what to do with NSEC DLV reply.
161 * @param qinfo: what was queried for.
162 * @param rep: the nonpositive reply.
163 * @param nm: dlv lookup name, to adjust for new lookup name (if needed).
164 * @param nm_len: length of lookup name.
165 * @return 0 on error, 1 if a higher point is found.
166 * 	If the higher point is above the dlv repo anchor, the qname does
167 * 	not exist.
168 */
169int val_nsec_check_dlv(struct query_info* qinfo,
170	struct reply_info* rep, uint8_t** nm, size_t* nm_len);
171
172/**
173 * Determine if an nsec proves an insecure delegation towards the qname.
174 * @param nsec: nsec rrset.
175 * @param qinfo: what was queries for.
176 * @return 0 if not, 1 if an NSEC that signals an insecure delegation to
177 * 	the qname.
178 */
179int val_nsec_proves_insecuredelegation(struct ub_packed_rrset_key* nsec,
180        struct query_info* qinfo);
181
182#endif /* VALIDATOR_VAL_NSEC_H */
183