1 /* 2 * validator/val_nsec3.h - validator NSEC3 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 NSEC3 checking, the different NSEC3 proofs 41 * for denial of existence, and proofs for presence of types. 42 * 43 * NSEC3 44 * 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 3 3 45 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 46 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 47 * | Hash Alg. | Flags | Iterations | 48 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 49 * | Salt Length | Salt / 50 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 51 * | Hash Length | Next Hashed Owner Name / 52 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 53 * / Type Bit Maps / 54 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 55 * 56 * NSEC3PARAM 57 * 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 3 3 58 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 59 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 60 * | Hash Alg. | Flags | Iterations | 61 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 62 * | Salt Length | Salt / 63 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 64 * 65 */ 66 67 #ifndef VALIDATOR_VAL_NSEC3_H 68 #define VALIDATOR_VAL_NSEC3_H 69 #include "util/rbtree.h" 70 #include "util/data/packed_rrset.h" 71 #include "sldns/rrdef.h" 72 struct val_env; 73 struct regional; 74 struct module_env; 75 struct module_qstate; 76 struct ub_packed_rrset_key; 77 struct reply_info; 78 struct query_info; 79 struct key_entry_key; 80 struct sldns_buffer; 81 82 /** 83 * 0 1 2 3 4 5 6 7 84 * +-+-+-+-+-+-+-+-+ 85 * | |O| 86 * +-+-+-+-+-+-+-+-+ 87 * The OPT-OUT bit in the NSEC3 flags field. 88 * If enabled, there can be zero or more unsigned delegations in the span. 89 * If disabled, there are zero unsigned delegations in the span. 90 */ 91 #define NSEC3_OPTOUT 0x01 92 /** 93 * The unknown flags in the NSEC3 flags field. 94 * They must be zero, or the NSEC3 is ignored. 95 */ 96 #define NSEC3_UNKNOWN_FLAGS 0xFE 97 98 /** The SHA1 hash algorithm for NSEC3 */ 99 #define NSEC3_HASH_SHA1 0x01 100 101 /** 102 * Determine if the set of NSEC3 records provided with a response prove NAME 103 * ERROR. This means that the NSEC3s prove a) the closest encloser exists, 104 * b) the direct child of the closest encloser towards qname doesn't exist, 105 * and c) *.closest encloser does not exist. 106 * 107 * @param env: module environment with temporary region and buffer. 108 * @param ve: validator environment, with iteration count settings. 109 * @param list: array of RRsets, some of which are NSEC3s. 110 * @param num: number of RRsets in the array to examine. 111 * @param qinfo: query that is verified for. 112 * @param kkey: key entry that signed the NSEC3s. 113 * @return: 114 * sec_status SECURE of the Name Error is proven by the NSEC3 RRs, 115 * BOGUS if not, INSECURE if all of the NSEC3s could be validly ignored. 116 */ 117 enum sec_status 118 nsec3_prove_nameerror(struct module_env* env, struct val_env* ve, 119 struct ub_packed_rrset_key** list, size_t num, 120 struct query_info* qinfo, struct key_entry_key* kkey); 121 122 /** 123 * Determine if the NSEC3s provided in a response prove the NOERROR/NODATA 124 * status. There are a number of different variants to this: 125 * 126 * 1) Normal NODATA -- qname is matched to an NSEC3 record, type is not 127 * present. 128 * 129 * 2) ENT NODATA -- because there must be NSEC3 record for 130 * empty-non-terminals, this is the same as #1. 131 * 132 * 3) NSEC3 ownername NODATA -- qname matched an existing, lone NSEC3 133 * ownername, but qtype was not NSEC3. NOTE: as of nsec-05, this case no 134 * longer exists. 135 * 136 * 4) Wildcard NODATA -- A wildcard matched the name, but not the type. 137 * 138 * 5) Opt-In DS NODATA -- the qname is covered by an opt-in span and qtype == 139 * DS. (or maybe some future record with the same parent-side-only property) 140 * 141 * @param env: module environment with temporary region and buffer. 142 * @param ve: validator environment, with iteration count settings. 143 * @param list: array of RRsets, some of which are NSEC3s. 144 * @param num: number of RRsets in the array to examine. 145 * @param qinfo: query that is verified for. 146 * @param kkey: key entry that signed the NSEC3s. 147 * @return: 148 * sec_status SECURE of the proposition is proven by the NSEC3 RRs, 149 * BOGUS if not, INSECURE if all of the NSEC3s could be validly ignored. 150 */ 151 enum sec_status 152 nsec3_prove_nodata(struct module_env* env, struct val_env* ve, 153 struct ub_packed_rrset_key** list, size_t num, 154 struct query_info* qinfo, struct key_entry_key* kkey); 155 156 157 /** 158 * Prove that a positive wildcard match was appropriate (no direct match 159 * RRset). 160 * 161 * @param env: module environment with temporary region and buffer. 162 * @param ve: validator environment, with iteration count settings. 163 * @param list: array of RRsets, some of which are NSEC3s. 164 * @param num: number of RRsets in the array to examine. 165 * @param qinfo: query that is verified for. 166 * @param kkey: key entry that signed the NSEC3s. 167 * @param wc: The purported wildcard that matched. This is the wildcard name 168 * as *.wildcard.name., with the *. label already removed. 169 * @return: 170 * sec_status SECURE of the proposition is proven by the NSEC3 RRs, 171 * BOGUS if not, INSECURE if all of the NSEC3s could be validly ignored. 172 */ 173 enum sec_status 174 nsec3_prove_wildcard(struct module_env* env, struct val_env* ve, 175 struct ub_packed_rrset_key** list, size_t num, 176 struct query_info* qinfo, struct key_entry_key* kkey, uint8_t* wc); 177 178 /** 179 * Prove that a DS response either had no DS, or wasn't a delegation point. 180 * 181 * Fundamentally there are two cases here: normal NODATA and Opt-In NODATA. 182 * 183 * @param env: module environment with temporary region and buffer. 184 * @param ve: validator environment, with iteration count settings. 185 * @param list: array of RRsets, some of which are NSEC3s. 186 * @param num: number of RRsets in the array to examine. 187 * @param qinfo: query that is verified for. 188 * @param kkey: key entry that signed the NSEC3s. 189 * @param reason: string for bogus result. 190 * @param reason_bogus: EDE (RFC8914) code paired with the reason of failure. 191 * @param qstate: qstate with region. 192 * @return: 193 * sec_status SECURE of the proposition is proven by the NSEC3 RRs, 194 * BOGUS if not, INSECURE if all of the NSEC3s could be validly ignored. 195 * or if there was no DS in an insecure (i.e., opt-in) way, 196 * INDETERMINATE if it was clear that this wasn't a delegation point. 197 */ 198 enum sec_status 199 nsec3_prove_nods(struct module_env* env, struct val_env* ve, 200 struct ub_packed_rrset_key** list, size_t num, 201 struct query_info* qinfo, struct key_entry_key* kkey, char** reason, 202 sldns_ede_code* reason_bogus, struct module_qstate* qstate); 203 204 /** 205 * Prove NXDOMAIN or NODATA. 206 * 207 * @param env: module environment with temporary region and buffer. 208 * @param ve: validator environment, with iteration count settings. 209 * @param list: array of RRsets, some of which are NSEC3s. 210 * @param num: number of RRsets in the array to examine. 211 * @param qinfo: query that is verified for. 212 * @param kkey: key entry that signed the NSEC3s. 213 * @param nodata: if return value is secure, this indicates if nodata or 214 * nxdomain was proven. 215 * @return: 216 * sec_status SECURE of the proposition is proven by the NSEC3 RRs, 217 * BOGUS if not, INSECURE if all of the NSEC3s could be validly ignored. 218 */ 219 enum sec_status 220 nsec3_prove_nxornodata(struct module_env* env, struct val_env* ve, 221 struct ub_packed_rrset_key** list, size_t num, 222 struct query_info* qinfo, struct key_entry_key* kkey, int* nodata); 223 224 /** 225 * The NSEC3 hash result storage. 226 * Consists of an rbtree, with these nodes in it. 227 * The nodes detail how a set of parameters (from nsec3 rr) plus 228 * a dname result in a hash. 229 */ 230 struct nsec3_cached_hash { 231 /** rbtree node, key is this structure */ 232 rbnode_type node; 233 /** where are the parameters for conversion, in this rrset data */ 234 struct ub_packed_rrset_key* nsec3; 235 /** where are the parameters for conversion, this RR number in data */ 236 int rr; 237 /** the name to convert */ 238 uint8_t* dname; 239 /** length of the dname */ 240 size_t dname_len; 241 /** the hash result (not base32 encoded) */ 242 uint8_t* hash; 243 /** length of hash in bytes */ 244 size_t hash_len; 245 /** the hash result in base32 encoding */ 246 uint8_t* b32; 247 /** length of base32 encoding (as a label) */ 248 size_t b32_len; 249 }; 250 251 /** 252 * Rbtree for hash cache comparison function. 253 * @param c1: key 1. 254 * @param c2: key 2. 255 * @return: comparison code, -1, 0, 1, of the keys. 256 */ 257 int nsec3_hash_cmp(const void* c1, const void* c2); 258 259 /** 260 * Obtain the hash of an owner name. 261 * Used internally by the nsec3 proof functions in this file. 262 * published to enable unit testing of hash algorithms and cache. 263 * 264 * @param table: the cache table. Must be initialised at start. 265 * @param region: scratch region to use for allocation. 266 * This region holds the tree, if you wipe the region, reinit the tree. 267 * @param buf: temporary buffer. 268 * @param nsec3: the rrset with parameters 269 * @param rr: rr number from d that has the NSEC3 parameters to hash to. 270 * @param dname: name to hash 271 * This pointer is used inside the tree, assumed region-alloced. 272 * @param dname_len: the length of the name. 273 * @param hash: the hash node is returned on success. 274 * @return: 275 * 1 on success, either from cache or newly hashed hash is returned. 276 * 0 on a malloc failure. 277 * -1 if the NSEC3 rr was badly formatted (i.e. formerr). 278 */ 279 int nsec3_hash_name(rbtree_type* table, struct regional* region, 280 struct sldns_buffer* buf, struct ub_packed_rrset_key* nsec3, int rr, 281 uint8_t* dname, size_t dname_len, struct nsec3_cached_hash** hash); 282 283 /** 284 * Get next owner name, converted to base32 encoding and with the 285 * zone name (taken from the nsec3 owner name) appended. 286 * @param rrset: the NSEC3 rrset. 287 * @param r: the rr num of the nsec3 in the rrset. 288 * @param buf: buffer to store name in 289 * @param max: size of buffer. 290 * @return length of name on success. 0 on failure (buffer too short or 291 * bad format nsec3 record). 292 */ 293 size_t nsec3_get_nextowner_b32(struct ub_packed_rrset_key* rrset, int r, 294 uint8_t* buf, size_t max); 295 296 /** 297 * Convert hash into base32 encoding and with the 298 * zone name appended. 299 * @param hash: hashed buffer 300 * @param hashlen: length of hash 301 * @param zone: name of zone 302 * @param zonelen: length of zonename. 303 * @param buf: buffer to store name in 304 * @param max: size of buffer. 305 * @return length of name on success. 0 on failure (buffer too short or 306 * bad format nsec3 record). 307 */ 308 size_t nsec3_hash_to_b32(uint8_t* hash, size_t hashlen, uint8_t* zone, 309 size_t zonelen, uint8_t* buf, size_t max); 310 311 /** 312 * Get NSEC3 parameters out of rr. 313 * @param rrset: the NSEC3 rrset. 314 * @param r: the rr num of the nsec3 in the rrset. 315 * @param algo: nsec3 hash algo. 316 * @param iter: iteration count. 317 * @param salt: ptr to salt inside rdata. 318 * @param saltlen: length of salt. 319 * @return 0 if bad formatted, unknown nsec3 hash algo, or unknown flags set. 320 */ 321 int nsec3_get_params(struct ub_packed_rrset_key* rrset, int r, 322 int* algo, size_t* iter, uint8_t** salt, size_t* saltlen); 323 324 /** 325 * Get NSEC3 hashed in a buffer 326 * @param buf: buffer for temp use. 327 * @param nm: name to hash 328 * @param nmlen: length of nm. 329 * @param algo: algo to use, must be known. 330 * @param iter: iterations 331 * @param salt: salt for nsec3 332 * @param saltlen: length of salt. 333 * @param res: result of hash stored here. 334 * @param max: maximum space for result. 335 * @return 0 on failure, otherwise bytelength stored. 336 */ 337 size_t nsec3_get_hashed(struct sldns_buffer* buf, uint8_t* nm, size_t nmlen, 338 int algo, size_t iter, uint8_t* salt, size_t saltlen, uint8_t* res, 339 size_t max); 340 341 /** 342 * see if NSEC3 RR contains given type 343 * @param rrset: NSEC3 rrset 344 * @param r: RR in rrset 345 * @param type: in host order to check bit for. 346 * @return true if bit set, false if not or error. 347 */ 348 int nsec3_has_type(struct ub_packed_rrset_key* rrset, int r, uint16_t type); 349 350 /** 351 * return if nsec3 RR has the optout flag 352 * @param rrset: NSEC3 rrset 353 * @param r: RR in rrset 354 * @return true if optout, false on error or not optout 355 */ 356 int nsec3_has_optout(struct ub_packed_rrset_key* rrset, int r); 357 358 /** 359 * Return nsec3 RR next hashed owner name 360 * @param rrset: NSEC3 rrset 361 * @param r: RR in rrset 362 * @param next: ptr into rdata to next owner hash 363 * @param nextlen: length of hash. 364 * @return false on malformed 365 */ 366 int nsec3_get_nextowner(struct ub_packed_rrset_key* rrset, int r, 367 uint8_t** next, size_t* nextlen); 368 369 /** 370 * nsec3Covers 371 * Given a hash and a candidate NSEC3Record, determine if that NSEC3Record 372 * covers the hash. Covers specifically means that the hash is in between 373 * the owner and next hashes and does not equal either. 374 * 375 * @param zone: the zone name. 376 * @param hash: the hash of the name 377 * @param rrset: the rrset of the NSEC3. 378 * @param rr: which rr in the rrset. 379 * @param buf: temporary buffer. 380 * @return true if covers, false if not. 381 */ 382 int nsec3_covers(uint8_t* zone, struct nsec3_cached_hash* hash, 383 struct ub_packed_rrset_key* rrset, int rr, struct sldns_buffer* buf); 384 385 #endif /* VALIDATOR_VAL_NSEC3_H */ 386