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