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