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