unbound/validator/val_nsec.h

   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"
  47 struct val_env;
  48 struct module_env;
  49 struct ub_packed_rrset_key;
  50 struct reply_info;
  51 struct query_info;
  52 struct 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  */
  73 enum 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  */
  86 int 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  */
  96 int 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  */
 113 int 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  */
 124 int 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  */
 134 int 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  */
 145 uint8_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  */
 156 int 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  */
 169 int 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  */
 179 int val_nsec_proves_insecuredelegation(struct ub_packed_rrset_key* nsec,
 180         struct query_info* qinfo);
 181
 182 #endif /* VALIDATOR_VAL_NSEC_H */