1 /* 2 * validator/val_nsec.h - validator NSEC denial of existence 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 existence, 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" 47 struct val_env; 48 struct module_env; 49 struct module_qstate; 50 struct ub_packed_rrset_key; 51 struct reply_info; 52 struct query_info; 53 struct key_entry_key; 54 55 /** 56 * Check DS absence. 57 * There is a NODATA reply to a DS that needs checking. 58 * NSECs can prove this is not a delegation point, or successfully prove 59 * that there is no DS. Or this fails. 60 * 61 * @param env: module env for rrsig verification routines. 62 * @param ve: validator env for rrsig verification routines. 63 * @param qinfo: the DS queried for. 64 * @param rep: reply received. 65 * @param kkey: key entry to use for verification of signatures. 66 * @param proof_ttl: if secure, the TTL of how long this proof lasts. 67 * @param reason: string explaining why bogus. 68 * @param qstate: qstate with region. 69 * @return security status. 70 * SECURE: proved absence of DS. 71 * INSECURE: proved that this was not a delegation point. 72 * BOGUS: crypto bad, or no absence of DS proven. 73 * UNCHECKED: there was no way to prove anything (no NSECs, unknown algo). 74 */ 75 enum sec_status val_nsec_prove_nodata_dsreply(struct module_env* env, 76 struct val_env* ve, struct query_info* qinfo, 77 struct reply_info* rep, struct key_entry_key* kkey, 78 time_t* proof_ttl, char** reason, struct module_qstate* qstate); 79 80 /** 81 * nsec typemap check, takes an NSEC-type bitmap as argument, checks for type. 82 * @param bitmap: pointer to the bitmap part of wireformat rdata. 83 * @param len: length of the bitmap, in bytes. 84 * @param type: the type (in host order) to check for. 85 * @return true if the type bit was set in the bitmap. false if not, or 86 * if the bitmap was malformed in some way. 87 */ 88 int nsecbitmap_has_type_rdata(uint8_t* bitmap, size_t len, uint16_t type); 89 90 /** 91 * Check if type is present in the NSEC typemap 92 * @param nsec: the nsec RRset. 93 * If there are multiple RRs, then each must have the same typemap, 94 * since the typemap represents the types at this domain node. 95 * @param type: type to check for, host order. 96 * @return true if present 97 */ 98 int nsec_has_type(struct ub_packed_rrset_key* nsec, uint16_t type); 99 100 /** 101 * Determine if a NSEC proves the NOERROR/NODATA conditions. This will also 102 * handle the empty non-terminal (ENT) case and partially handle the 103 * wildcard case. If the ownername of 'nsec' is a wildcard, the validator 104 * must still be provided proof that qname did not directly exist and that 105 * the wildcard is, in fact, *.closest_encloser. 106 * 107 * @param nsec: the nsec record to check against. 108 * @param qinfo: the query info. 109 * @param wc: if the nodata is proven for a wildcard match, the wildcard 110 * closest encloser is returned, else NULL (wc is unchanged). 111 * This closest encloser must then match the nameerror given for the 112 * nextcloser of qname. 113 * @return true if NSEC proves this. 114 */ 115 int nsec_proves_nodata(struct ub_packed_rrset_key* nsec, 116 struct query_info* qinfo, uint8_t** wc); 117 118 /** 119 * Determine if the given NSEC proves a NameError (NXDOMAIN) for a given 120 * qname. 121 * 122 * @param nsec: the nsec to check 123 * @param qname: what was queried. 124 * @return true if proven. 125 */ 126 int val_nsec_proves_name_error(struct ub_packed_rrset_key* nsec, 127 uint8_t* qname); 128 129 /** 130 * Determine if the given NSEC proves a positive wildcard response. 131 * @param nsec: the nsec to check 132 * @param qinf: what was queried. 133 * @param wc: wildcard (without *. label) 134 * @return true if proven. 135 */ 136 int val_nsec_proves_positive_wildcard(struct ub_packed_rrset_key* nsec, 137 struct query_info* qinf, uint8_t* wc); 138 139 /** 140 * Determine closest encloser of a query name and the NSEC that covers it 141 * (and thus disproved it). 142 * A name error must have been proven already, otherwise this will be invalid. 143 * @param qname: the name queried for. 144 * @param nsec: the nsec RRset. 145 * @return closest encloser dname or NULL on error (bad nsec RRset). 146 */ 147 uint8_t* nsec_closest_encloser(uint8_t* qname, 148 struct ub_packed_rrset_key* nsec); 149 150 /** 151 * Determine if the given NSEC proves that a wildcard match does not exist. 152 * 153 * @param nsec: the nsec RRset. 154 * @param qname: the name queried for. 155 * @param qnamelen: length of qname. 156 * @return true if proven. 157 */ 158 int val_nsec_proves_no_wc(struct ub_packed_rrset_key* nsec, uint8_t* qname, 159 size_t qnamelen); 160 161 /** 162 * Determine if an nsec proves an insecure delegation towards the qname. 163 * @param nsec: nsec rrset. 164 * @param qinfo: what was queries for. 165 * @return 0 if not, 1 if an NSEC that signals an insecure delegation to 166 * the qname. 167 */ 168 int val_nsec_proves_insecuredelegation(struct ub_packed_rrset_key* nsec, 169 struct query_info* qinfo); 170 171 #endif /* VALIDATOR_VAL_NSEC_H */ 172