1 /* 2 * validator/val_sigcrypt.h - validator signature crypto 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 signature verification and checking, the 41 * bridging between RR wireformat data and crypto calls. 42 */ 43 44 #ifndef VALIDATOR_VAL_SIGCRYPT_H 45 #define VALIDATOR_VAL_SIGCRYPT_H 46 #include "util/data/packed_rrset.h" 47 #include "sldns/pkthdr.h" 48 #include "sldns/rrdef.h" 49 struct val_env; 50 struct module_env; 51 struct module_qstate; 52 struct ub_packed_rrset_key; 53 struct rbtree_type; 54 struct regional; 55 struct sldns_buffer; 56 57 /** number of entries in algorithm needs array */ 58 #define ALGO_NEEDS_MAX 256 59 60 /** 61 * Storage for algorithm needs. DNSKEY algorithms. 62 */ 63 struct algo_needs { 64 /** the algorithms (8-bit) with each a number. 65 * 0: not marked. 66 * 1: marked 'necessary but not yet fulfilled' 67 * 2: marked bogus. 68 * Indexed by algorithm number. 69 */ 70 uint8_t needs[ALGO_NEEDS_MAX]; 71 /** the number of entries in the array that are unfulfilled */ 72 size_t num; 73 }; 74 75 /** 76 * Initialize algo needs structure, set algos from rrset as needed. 77 * Results are added to an existing need structure. 78 * @param n: struct with storage. 79 * @param dnskey: algos from this struct set as necessary. DNSKEY set. 80 * @param sigalg: adds to signalled algorithm list too. 81 */ 82 void algo_needs_init_dnskey_add(struct algo_needs* n, 83 struct ub_packed_rrset_key* dnskey, uint8_t* sigalg); 84 85 /** 86 * Initialize algo needs structure from a signalled algo list. 87 * @param n: struct with storage. 88 * @param sigalg: signalled algorithm list, numbers ends with 0. 89 */ 90 void algo_needs_init_list(struct algo_needs* n, uint8_t* sigalg); 91 92 /** 93 * Initialize algo needs structure, set algos from rrset as needed. 94 * @param n: struct with storage. 95 * @param ds: algos from this struct set as necessary. DS set. 96 * @param fav_ds_algo: filter to use only this DS algo. 97 * @param sigalg: list of signalled algos, constructed as output, 98 * provide size ALGO_NEEDS_MAX+1. list of algonumbers, ends with a zero. 99 */ 100 void algo_needs_init_ds(struct algo_needs* n, struct ub_packed_rrset_key* ds, 101 int fav_ds_algo, uint8_t* sigalg); 102 103 /** 104 * Mark this algorithm as a success, sec_secure, and see if we are done. 105 * @param n: storage structure processed. 106 * @param algo: the algorithm processed to be secure. 107 * @return if true, processing has finished successfully, we are satisfied. 108 */ 109 int algo_needs_set_secure(struct algo_needs* n, uint8_t algo); 110 111 /** 112 * Mark this algorithm a failure, sec_bogus. It can later be overridden 113 * by a success for this algorithm (with a different signature). 114 * @param n: storage structure processed. 115 * @param algo: the algorithm processed to be bogus. 116 */ 117 void algo_needs_set_bogus(struct algo_needs* n, uint8_t algo); 118 119 /** 120 * See how many algorithms are missing (not bogus or secure, but not processed) 121 * @param n: storage structure processed. 122 * @return number of algorithms missing after processing. 123 */ 124 size_t algo_needs_num_missing(struct algo_needs* n); 125 126 /** 127 * See which algo is missing. 128 * @param n: struct after processing. 129 * @return if 0 an algorithm was bogus, if a number, this algorithm was 130 * missing. So on 0, report why that was bogus, on number report a missing 131 * algorithm. There could be multiple missing, this reports the first one. 132 */ 133 int algo_needs_missing(struct algo_needs* n); 134 135 /** 136 * Format error reason for algorithm missing. 137 * @param env: module env with scratch for temp storage of string. 138 * @param alg: DNSKEY-algorithm missing. 139 * @param reason: destination. 140 * @param s: string, appended with 'with algorithm ..'. 141 */ 142 void algo_needs_reason(struct module_env* env, int alg, char** reason, char* s); 143 144 /** 145 * Check if dnskey matches a DS digest 146 * Does not check dnskey-keyid footprint, just the digest. 147 * @param env: module environment. Uses scratch space. 148 * @param dnskey_rrset: DNSKEY rrset. 149 * @param dnskey_idx: index of RR in rrset. 150 * @param ds_rrset: DS rrset 151 * @param ds_idx: index of RR in DS rrset. 152 * @return true if it matches, false on error, not supported or no match. 153 */ 154 int ds_digest_match_dnskey(struct module_env* env, 155 struct ub_packed_rrset_key* dnskey_rrset, size_t dnskey_idx, 156 struct ub_packed_rrset_key* ds_rrset, size_t ds_idx); 157 158 /** 159 * Get dnskey keytag, footprint value 160 * @param dnskey_rrset: DNSKEY rrset. 161 * @param dnskey_idx: index of RR in rrset. 162 * @return the keytag or 0 for badly formatted DNSKEYs. 163 */ 164 uint16_t dnskey_calc_keytag(struct ub_packed_rrset_key* dnskey_rrset, 165 size_t dnskey_idx); 166 167 /** 168 * Get DS keytag, footprint value that matches the DNSKEY keytag it signs. 169 * @param ds_rrset: DS rrset 170 * @param ds_idx: index of RR in DS rrset. 171 * @return the keytag or 0 for badly formatted DSs. 172 */ 173 uint16_t ds_get_keytag(struct ub_packed_rrset_key* ds_rrset, size_t ds_idx); 174 175 /** 176 * See if DNSKEY algorithm is supported 177 * @param dnskey_rrset: DNSKEY rrset. 178 * @param dnskey_idx: index of RR in rrset. 179 * @return true if supported. 180 */ 181 int dnskey_algo_is_supported(struct ub_packed_rrset_key* dnskey_rrset, 182 size_t dnskey_idx); 183 184 /** 185 * See if the DNSKEY size at that algorithm is supported. 186 * @param dnskey_rrset: DNSKEY rrset. 187 * @param dnskey_idx: index of RR in rrset. 188 * @return true if supported. 189 */ 190 int dnskey_size_is_supported(struct ub_packed_rrset_key* dnskey_rrset, 191 size_t dnskey_idx); 192 193 /** 194 * See if the DNSKEY size at that algorithm is supported for all the 195 * RRs in the DNSKEY RRset. 196 * @param dnskey_rrset: DNSKEY rrset. 197 * @return true if supported. 198 */ 199 int dnskeyset_size_is_supported(struct ub_packed_rrset_key* dnskey_rrset); 200 201 /** 202 * See if DS digest algorithm is supported 203 * @param ds_rrset: DS rrset 204 * @param ds_idx: index of RR in DS rrset. 205 * @return true if supported. 206 */ 207 int ds_digest_algo_is_supported(struct ub_packed_rrset_key* ds_rrset, 208 size_t ds_idx); 209 210 /** 211 * Get DS RR digest algorithm 212 * @param ds_rrset: DS rrset. 213 * @param ds_idx: which DS. 214 * @return algorithm or 0 if DS too short. 215 */ 216 int ds_get_digest_algo(struct ub_packed_rrset_key* ds_rrset, size_t ds_idx); 217 218 /** 219 * See if DS key algorithm is supported 220 * @param ds_rrset: DS rrset 221 * @param ds_idx: index of RR in DS rrset. 222 * @return true if supported. 223 */ 224 int ds_key_algo_is_supported(struct ub_packed_rrset_key* ds_rrset, 225 size_t ds_idx); 226 227 /** 228 * Get DS RR key algorithm. This value should match with the DNSKEY algo. 229 * @param k: DS rrset. 230 * @param idx: which DS. 231 * @return algorithm or 0 if DS too short. 232 */ 233 int ds_get_key_algo(struct ub_packed_rrset_key* k, size_t idx); 234 235 /** 236 * Get DNSKEY RR signature algorithm 237 * @param k: DNSKEY rrset. 238 * @param idx: which DNSKEY RR. 239 * @return algorithm or 0 if DNSKEY too short. 240 */ 241 int dnskey_get_algo(struct ub_packed_rrset_key* k, size_t idx); 242 243 /** 244 * Get DNSKEY RR flags 245 * @param k: DNSKEY rrset. 246 * @param idx: which DNSKEY RR. 247 * @return flags or 0 if DNSKEY too short. 248 */ 249 uint16_t dnskey_get_flags(struct ub_packed_rrset_key* k, size_t idx); 250 251 /** 252 * Verify rrset against dnskey rrset. 253 * @param env: module environment, scratch space is used. 254 * @param ve: validator environment, date settings. 255 * @param rrset: to be validated. 256 * @param dnskey: DNSKEY rrset, keyset to try. 257 * @param sigalg: if nonNULL provide downgrade protection otherwise one 258 * algorithm is enough. 259 * @param reason: if bogus, a string returned, fixed or alloced in scratch. 260 * @param reason_bogus: EDE (RFC8914) code paired with the reason of failure. 261 * @param section: section of packet where this rrset comes from. 262 * @param qstate: qstate with region. 263 * @return SECURE if one key in the set verifies one rrsig. 264 * UNCHECKED on allocation errors, unsupported algorithms, malformed data, 265 * and BOGUS on verification failures (no keys match any signatures). 266 */ 267 enum sec_status dnskeyset_verify_rrset(struct module_env* env, 268 struct val_env* ve, struct ub_packed_rrset_key* rrset, 269 struct ub_packed_rrset_key* dnskey, uint8_t* sigalg, 270 char** reason, sldns_ede_code *reason_bogus, 271 sldns_pkt_section section, struct module_qstate* qstate); 272 273 274 /** 275 * verify rrset against one specific dnskey (from rrset) 276 * @param env: module environment, scratch space is used. 277 * @param ve: validator environment, date settings. 278 * @param rrset: to be validated. 279 * @param dnskey: DNSKEY rrset, keyset. 280 * @param dnskey_idx: which key from the rrset to try. 281 * @param reason: if bogus, a string returned, fixed or alloced in scratch. 282 * @param reason_bogus: EDE (RFC8914) code paired with the reason of failure. 283 * @param section: section of packet where this rrset comes from. 284 * @param qstate: qstate with region. 285 * @return secure if *this* key signs any of the signatures on rrset. 286 * unchecked on error or and bogus on bad signature. 287 */ 288 enum sec_status dnskey_verify_rrset(struct module_env* env, struct val_env* ve, 289 struct ub_packed_rrset_key* rrset, struct ub_packed_rrset_key* dnskey, 290 size_t dnskey_idx, char** reason, sldns_ede_code *reason_bogus, 291 sldns_pkt_section section, struct module_qstate* qstate); 292 293 /** 294 * verify rrset, with specific dnskey(from set), for a specific rrsig 295 * @param region: scratch region used for temporary allocation. 296 * @param buf: scratch buffer used for canonicalized rrset data. 297 * @param ve: validator environment, date settings. 298 * @param now: current time for validation (can be overridden). 299 * @param rrset: to be validated. 300 * @param dnskey: DNSKEY rrset, keyset. 301 * @param dnskey_idx: which key from the rrset to try. 302 * @param sig_idx: which signature to try to validate. 303 * @param sortree: pass NULL at start, the sorted rrset order is returned. 304 * pass it again for the same rrset. 305 * @param buf_canon: if true, the buffer is already canonical. 306 * pass false at start. pass old value only for same rrset and same 307 * signature (but perhaps different key) for reuse. 308 * @param reason: if bogus, a string returned, fixed or alloced in scratch. 309 * @param reason_bogus: EDE (8914) code paired with the reason of failure. 310 * @param section: section of packet where this rrset comes from. 311 * @param qstate: qstate with region. 312 * @return secure if this key signs this signature. unchecked on error or 313 * bogus if it did not validate. 314 */ 315 enum sec_status dnskey_verify_rrset_sig(struct regional* region, 316 struct sldns_buffer* buf, struct val_env* ve, time_t now, 317 struct ub_packed_rrset_key* rrset, struct ub_packed_rrset_key* dnskey, 318 size_t dnskey_idx, size_t sig_idx, 319 struct rbtree_type** sortree, int* buf_canon, 320 char** reason, sldns_ede_code *reason_bogus, 321 sldns_pkt_section section, struct module_qstate* qstate); 322 323 /** 324 * canonical compare for two tree entries 325 */ 326 int canonical_tree_compare(const void* k1, const void* k2); 327 328 /** 329 * Compare two rrsets and see if they are the same, canonicalised. 330 * The rrsets are not altered. 331 * @param region: temporary region. 332 * @param k1: rrset1 333 * @param k2: rrset2 334 * @return true if equal. 335 */ 336 int rrset_canonical_equal(struct regional* region, 337 struct ub_packed_rrset_key* k1, struct ub_packed_rrset_key* k2); 338 339 /** 340 * Canonicalize an rrset into the buffer. For an auth zone record, so 341 * this does not use a signature, or the RRSIG TTL or the wildcard label 342 * count from the RRSIG. 343 * @param region: temporary region. 344 * @param buf: the buffer to use. 345 * @param k: the rrset to insert. 346 * @return false on alloc error. 347 */ 348 int rrset_canonicalize_to_buffer(struct regional* region, 349 struct sldns_buffer* buf, struct ub_packed_rrset_key* k); 350 351 #endif /* VALIDATOR_VAL_SIGCRYPT_H */ 352