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