1 /* 2 * validator/val_nsec3.h - validator NSEC3 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 LIMITED 25 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 26 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE 27 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 28 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 29 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 30 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 31 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 32 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 33 * 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 existance, 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 79 /** 80 * 0 1 2 3 4 5 6 7 81 * +-+-+-+-+-+-+-+-+ 82 * | |O| 83 * +-+-+-+-+-+-+-+-+ 84 * The OPT-OUT bit in the NSEC3 flags field. 85 * If enabled, there can be zero or more unsigned delegations in the span. 86 * If disabled, there are zero unsigned delegations in the span. 87 */ 88 #define NSEC3_OPTOUT 0x01 89 /** 90 * The unknown flags in the NSEC3 flags field. 91 * They must be zero, or the NSEC3 is ignored. 92 */ 93 #define NSEC3_UNKNOWN_FLAGS 0xFE 94 95 /** The SHA1 hash algorithm for NSEC3 */ 96 #define NSEC3_HASH_SHA1 0x01 97 98 /** 99 * Determine if the set of NSEC3 records provided with a response prove NAME 100 * ERROR. This means that the NSEC3s prove a) the closest encloser exists, 101 * b) the direct child of the closest encloser towards qname doesn't exist, 102 * and c) *.closest encloser does not exist. 103 * 104 * @param env: module environment with temporary region and buffer. 105 * @param ve: validator environment, with iteration count settings. 106 * @param list: array of RRsets, some of which are NSEC3s. 107 * @param num: number of RRsets in the array to examine. 108 * @param qinfo: query that is verified for. 109 * @param kkey: key entry that signed the NSEC3s. 110 * @return: 111 * sec_status SECURE of the Name Error is proven by the NSEC3 RRs, 112 * BOGUS if not, INSECURE if all of the NSEC3s could be validly ignored. 113 */ 114 enum sec_status 115 nsec3_prove_nameerror(struct module_env* env, struct val_env* ve, 116 struct ub_packed_rrset_key** list, size_t num, 117 struct query_info* qinfo, struct key_entry_key* kkey); 118 119 /** 120 * Determine if the NSEC3s provided in a response prove the NOERROR/NODATA 121 * status. There are a number of different variants to this: 122 * 123 * 1) Normal NODATA -- qname is matched to an NSEC3 record, type is not 124 * present. 125 * 126 * 2) ENT NODATA -- because there must be NSEC3 record for 127 * empty-non-terminals, this is the same as #1. 128 * 129 * 3) NSEC3 ownername NODATA -- qname matched an existing, lone NSEC3 130 * ownername, but qtype was not NSEC3. NOTE: as of nsec-05, this case no 131 * longer exists. 132 * 133 * 4) Wildcard NODATA -- A wildcard matched the name, but not the type. 134 * 135 * 5) Opt-In DS NODATA -- the qname is covered by an opt-in span and qtype == 136 * DS. (or maybe some future record with the same parent-side-only property) 137 * 138 * @param env: module environment with temporary region and buffer. 139 * @param ve: validator environment, with iteration count settings. 140 * @param list: array of RRsets, some of which are NSEC3s. 141 * @param num: number of RRsets in the array to examine. 142 * @param qinfo: query that is verified for. 143 * @param kkey: key entry that signed the NSEC3s. 144 * @return: 145 * sec_status SECURE of the proposition is proven by the NSEC3 RRs, 146 * BOGUS if not, INSECURE if all of the NSEC3s could be validly ignored. 147 */ 148 enum sec_status 149 nsec3_prove_nodata(struct module_env* env, struct val_env* ve, 150 struct ub_packed_rrset_key** list, size_t num, 151 struct query_info* qinfo, struct key_entry_key* kkey); 152 153 154 /** 155 * Prove that a positive wildcard match was appropriate (no direct match 156 * RRset). 157 * 158 * @param env: module environment with temporary region and buffer. 159 * @param ve: validator environment, with iteration count settings. 160 * @param list: array of RRsets, some of which are NSEC3s. 161 * @param num: number of RRsets in the array to examine. 162 * @param qinfo: query that is verified for. 163 * @param kkey: key entry that signed the NSEC3s. 164 * @param wc: The purported wildcard that matched. This is the wildcard name 165 * as *.wildcard.name., with the *. label already removed. 166 * @return: 167 * sec_status SECURE of the proposition is proven by the NSEC3 RRs, 168 * BOGUS if not, INSECURE if all of the NSEC3s could be validly ignored. 169 */ 170 enum sec_status 171 nsec3_prove_wildcard(struct module_env* env, struct val_env* ve, 172 struct ub_packed_rrset_key** list, size_t num, 173 struct query_info* qinfo, struct key_entry_key* kkey, uint8_t* wc); 174 175 /** 176 * Prove that a DS response either had no DS, or wasn't a delegation point. 177 * 178 * Fundamentally there are two cases here: normal NODATA and Opt-In NODATA. 179 * 180 * @param env: module environment with temporary region and buffer. 181 * @param ve: validator environment, with iteration count settings. 182 * @param list: array of RRsets, some of which are NSEC3s. 183 * @param num: number of RRsets in the array to examine. 184 * @param qinfo: query that is verified for. 185 * @param kkey: key entry that signed the NSEC3s. 186 * @param reason: string for bogus result. 187 * @return: 188 * sec_status SECURE of the proposition is proven by the NSEC3 RRs, 189 * BOGUS if not, INSECURE if all of the NSEC3s could be validly ignored. 190 * or if there was no DS in an insecure (i.e., opt-in) way, 191 * INDETERMINATE if it was clear that this wasn't a delegation point. 192 */ 193 enum sec_status 194 nsec3_prove_nods(struct module_env* env, struct val_env* ve, 195 struct ub_packed_rrset_key** list, size_t num, 196 struct query_info* qinfo, struct key_entry_key* kkey, char** reason); 197 198 /** 199 * Prove NXDOMAIN or NODATA. 200 * 201 * @param env: module environment with temporary region and buffer. 202 * @param ve: validator environment, with iteration count settings. 203 * @param list: array of RRsets, some of which are NSEC3s. 204 * @param num: number of RRsets in the array to examine. 205 * @param qinfo: query that is verified for. 206 * @param kkey: key entry that signed the NSEC3s. 207 * @param nodata: if return value is secure, this indicates if nodata or 208 * nxdomain was proven. 209 * @return: 210 * sec_status SECURE of the proposition is proven by the NSEC3 RRs, 211 * BOGUS if not, INSECURE if all of the NSEC3s could be validly ignored. 212 */ 213 enum sec_status 214 nsec3_prove_nxornodata(struct module_env* env, struct val_env* ve, 215 struct ub_packed_rrset_key** list, size_t num, 216 struct query_info* qinfo, struct key_entry_key* kkey, int* nodata); 217 218 /** 219 * The NSEC3 hash result storage. 220 * Consists of an rbtree, with these nodes in it. 221 * The nodes detail how a set of parameters (from nsec3 rr) plus 222 * a dname result in a hash. 223 */ 224 struct nsec3_cached_hash { 225 /** rbtree node, key is this structure */ 226 rbnode_t node; 227 /** where are the parameters for conversion, in this rrset data */ 228 struct ub_packed_rrset_key* nsec3; 229 /** where are the parameters for conversion, this RR number in data */ 230 int rr; 231 /** the name to convert */ 232 uint8_t* dname; 233 /** length of the dname */ 234 size_t dname_len; 235 /** the hash result (not base32 encoded) */ 236 uint8_t* hash; 237 /** length of hash in bytes */ 238 size_t hash_len; 239 /** the hash result in base32 encoding */ 240 uint8_t* b32; 241 /** length of base32 encoding (as a label) */ 242 size_t b32_len; 243 }; 244 245 /** 246 * Rbtree for hash cache comparison function. 247 * @param c1: key 1. 248 * @param c2: key 2. 249 * @return: comparison code, -1, 0, 1, of the keys. 250 */ 251 int nsec3_hash_cmp(const void* c1, const void* c2); 252 253 /** 254 * Obtain the hash of an owner name. 255 * Used internally by the nsec3 proof functions in this file. 256 * published to enable unit testing of hash algorithms and cache. 257 * 258 * @param table: the cache table. Must be inited at start. 259 * @param region: scratch region to use for allocation. 260 * This region holds the tree, if you wipe the region, reinit the tree. 261 * @param buf: temporary buffer. 262 * @param nsec3: the rrset with parameters 263 * @param rr: rr number from d that has the NSEC3 parameters to hash to. 264 * @param dname: name to hash 265 * This pointer is used inside the tree, assumed region-alloced. 266 * @param dname_len: the length of the name. 267 * @param hash: the hash node is returned on success. 268 * @return: 269 * 1 on success, either from cache or newly hashed hash is returned. 270 * 0 on a malloc failure. 271 * -1 if the NSEC3 rr was badly formatted (i.e. formerr). 272 */ 273 int nsec3_hash_name(rbtree_t* table, struct regional* region, ldns_buffer* buf, 274 struct ub_packed_rrset_key* nsec3, int rr, uint8_t* dname, 275 size_t dname_len, struct nsec3_cached_hash** hash); 276 277 /** 278 * Get next owner name, converted to base32 encoding and with the 279 * zone name (taken from the nsec3 owner name) appended. 280 * @param rrset: the NSEC3 rrset. 281 * @param r: the rr num of the nsec3 in the rrset. 282 * @param buf: buffer to store name in 283 * @param max: size of buffer. 284 * @return length of name on success. 0 on failure (buffer too short or 285 * bad format nsec3 record). 286 */ 287 size_t nsec3_get_nextowner_b32(struct ub_packed_rrset_key* rrset, int r, 288 uint8_t* buf, size_t max); 289 290 /** 291 * Convert hash into base32 encoding and with the 292 * zone name appended. 293 * @param hash: hashed buffer 294 * @param hashlen: length of hash 295 * @param zone: name of zone 296 * @param zonelen: length of zonename. 297 * @param buf: buffer to store name in 298 * @param max: size of buffer. 299 * @return length of name on success. 0 on failure (buffer too short or 300 * bad format nsec3 record). 301 */ 302 size_t nsec3_hash_to_b32(uint8_t* hash, size_t hashlen, uint8_t* zone, 303 size_t zonelen, uint8_t* buf, size_t max); 304 305 /** 306 * Get NSEC3 parameters out of rr. 307 * @param rrset: the NSEC3 rrset. 308 * @param r: the rr num of the nsec3 in the rrset. 309 * @param algo: nsec3 hash algo. 310 * @param iter: iteration count. 311 * @param salt: ptr to salt inside rdata. 312 * @param saltlen: length of salt. 313 * @return 0 if bad formatted, unknown nsec3 hash algo, or unknown flags set. 314 */ 315 int nsec3_get_params(struct ub_packed_rrset_key* rrset, int r, 316 int* algo, size_t* iter, uint8_t** salt, size_t* saltlen); 317 318 /** 319 * Get NSEC3 hashed in a buffer 320 * @param buf: buffer for temp use. 321 * @param nm: name to hash 322 * @param nmlen: length of nm. 323 * @param algo: algo to use, must be known. 324 * @param iter: iterations 325 * @param salt: salt for nsec3 326 * @param saltlen: length of salt. 327 * @param res: result of hash stored here. 328 * @param max: maximum space for result. 329 * @return 0 on failure, otherwise bytelength stored. 330 */ 331 size_t nsec3_get_hashed(ldns_buffer* buf, uint8_t* nm, size_t nmlen, int algo, 332 size_t iter, uint8_t* salt, size_t saltlen, uint8_t* res, size_t max); 333 334 /** 335 * see if NSEC3 RR contains given type 336 * @param rrset: NSEC3 rrset 337 * @param r: RR in rrset 338 * @param type: in host order to check bit for. 339 * @return true if bit set, false if not or error. 340 */ 341 int nsec3_has_type(struct ub_packed_rrset_key* rrset, int r, uint16_t type); 342 343 /** 344 * return if nsec3 RR has the optout flag 345 * @param rrset: NSEC3 rrset 346 * @param r: RR in rrset 347 * @return true if optout, false on error or not optout 348 */ 349 int nsec3_has_optout(struct ub_packed_rrset_key* rrset, int r); 350 351 /** 352 * Return nsec3 RR next hashed owner name 353 * @param rrset: NSEC3 rrset 354 * @param r: RR in rrset 355 * @param next: ptr into rdata to next owner hash 356 * @param nextlen: length of hash. 357 * @return false on malformed 358 */ 359 int nsec3_get_nextowner(struct ub_packed_rrset_key* rrset, int r, 360 uint8_t** next, size_t* nextlen); 361 362 /** 363 * nsec3Covers 364 * Given a hash and a candidate NSEC3Record, determine if that NSEC3Record 365 * covers the hash. Covers specifically means that the hash is in between 366 * the owner and next hashes and does not equal either. 367 * 368 * @param zone: the zone name. 369 * @param hash: the hash of the name 370 * @param rrset: the rrset of the NSEC3. 371 * @param rr: which rr in the rrset. 372 * @param buf: temporary buffer. 373 * @return true if covers, false if not. 374 */ 375 int nsec3_covers(uint8_t* zone, struct nsec3_cached_hash* hash, 376 struct ub_packed_rrset_key* rrset, int rr, ldns_buffer* buf); 377 378 #endif /* VALIDATOR_VAL_NSEC3_H */ 379