1 /* 2 * Copyright 2001-2018 The OpenSSL Project Authors. All Rights Reserved. 3 * Copyright (c) 2002, Oracle and/or its affiliates. All rights reserved 4 * 5 * Licensed under the OpenSSL license (the "License"). You may not use 6 * this file except in compliance with the License. You can obtain a copy 7 * in the file LICENSE in the source distribution or at 8 * https://www.openssl.org/source/license.html 9 */ 10 11 #include "eng_int.h" 12 13 /* 14 * The linked-list of pointers to engine types. engine_list_head incorporates 15 * an implicit structural reference but engine_list_tail does not - the 16 * latter is a computational optimization and only points to something that 17 * is already pointed to by its predecessor in the list (or engine_list_head 18 * itself). In the same way, the use of the "prev" pointer in each ENGINE is 19 * to save excessive list iteration, it doesn't correspond to an extra 20 * structural reference. Hence, engine_list_head, and each non-null "next" 21 * pointer account for the list itself assuming exactly 1 structural 22 * reference on each list member. 23 */ 24 static ENGINE *engine_list_head = NULL; 25 static ENGINE *engine_list_tail = NULL; 26 27 /* 28 * This cleanup function is only needed internally. If it should be called, 29 * we register it with the "engine_cleanup_int()" stack to be called during 30 * cleanup. 31 */ 32 33 static void engine_list_cleanup(void) 34 { 35 ENGINE *iterator = engine_list_head; 36 37 while (iterator != NULL) { 38 ENGINE_remove(iterator); 39 iterator = engine_list_head; 40 } 41 return; 42 } 43 44 /* 45 * These static functions starting with a lower case "engine_" always take 46 * place when global_engine_lock has been locked up. 47 */ 48 static int engine_list_add(ENGINE *e) 49 { 50 int conflict = 0; 51 ENGINE *iterator = NULL; 52 53 if (e == NULL) { 54 ENGINEerr(ENGINE_F_ENGINE_LIST_ADD, ERR_R_PASSED_NULL_PARAMETER); 55 return 0; 56 } 57 iterator = engine_list_head; 58 while (iterator && !conflict) { 59 conflict = (strcmp(iterator->id, e->id) == 0); 60 iterator = iterator->next; 61 } 62 if (conflict) { 63 ENGINEerr(ENGINE_F_ENGINE_LIST_ADD, ENGINE_R_CONFLICTING_ENGINE_ID); 64 return 0; 65 } 66 if (engine_list_head == NULL) { 67 /* We are adding to an empty list. */ 68 if (engine_list_tail) { 69 ENGINEerr(ENGINE_F_ENGINE_LIST_ADD, ENGINE_R_INTERNAL_LIST_ERROR); 70 return 0; 71 } 72 engine_list_head = e; 73 e->prev = NULL; 74 /* 75 * The first time the list allocates, we should register the cleanup. 76 */ 77 engine_cleanup_add_last(engine_list_cleanup); 78 } else { 79 /* We are adding to the tail of an existing list. */ 80 if ((engine_list_tail == NULL) || (engine_list_tail->next != NULL)) { 81 ENGINEerr(ENGINE_F_ENGINE_LIST_ADD, ENGINE_R_INTERNAL_LIST_ERROR); 82 return 0; 83 } 84 engine_list_tail->next = e; 85 e->prev = engine_list_tail; 86 } 87 /* 88 * Having the engine in the list assumes a structural reference. 89 */ 90 e->struct_ref++; 91 engine_ref_debug(e, 0, 1); 92 /* However it came to be, e is the last item in the list. */ 93 engine_list_tail = e; 94 e->next = NULL; 95 return 1; 96 } 97 98 static int engine_list_remove(ENGINE *e) 99 { 100 ENGINE *iterator; 101 102 if (e == NULL) { 103 ENGINEerr(ENGINE_F_ENGINE_LIST_REMOVE, ERR_R_PASSED_NULL_PARAMETER); 104 return 0; 105 } 106 /* We need to check that e is in our linked list! */ 107 iterator = engine_list_head; 108 while (iterator && (iterator != e)) 109 iterator = iterator->next; 110 if (iterator == NULL) { 111 ENGINEerr(ENGINE_F_ENGINE_LIST_REMOVE, 112 ENGINE_R_ENGINE_IS_NOT_IN_LIST); 113 return 0; 114 } 115 /* un-link e from the chain. */ 116 if (e->next) 117 e->next->prev = e->prev; 118 if (e->prev) 119 e->prev->next = e->next; 120 /* Correct our head/tail if necessary. */ 121 if (engine_list_head == e) 122 engine_list_head = e->next; 123 if (engine_list_tail == e) 124 engine_list_tail = e->prev; 125 engine_free_util(e, 0); 126 return 1; 127 } 128 129 /* Get the first/last "ENGINE" type available. */ 130 ENGINE *ENGINE_get_first(void) 131 { 132 ENGINE *ret; 133 134 if (!RUN_ONCE(&engine_lock_init, do_engine_lock_init)) { 135 ENGINEerr(ENGINE_F_ENGINE_GET_FIRST, ERR_R_MALLOC_FAILURE); 136 return NULL; 137 } 138 139 CRYPTO_THREAD_write_lock(global_engine_lock); 140 ret = engine_list_head; 141 if (ret) { 142 ret->struct_ref++; 143 engine_ref_debug(ret, 0, 1); 144 } 145 CRYPTO_THREAD_unlock(global_engine_lock); 146 return ret; 147 } 148 149 ENGINE *ENGINE_get_last(void) 150 { 151 ENGINE *ret; 152 153 if (!RUN_ONCE(&engine_lock_init, do_engine_lock_init)) { 154 ENGINEerr(ENGINE_F_ENGINE_GET_LAST, ERR_R_MALLOC_FAILURE); 155 return NULL; 156 } 157 158 CRYPTO_THREAD_write_lock(global_engine_lock); 159 ret = engine_list_tail; 160 if (ret) { 161 ret->struct_ref++; 162 engine_ref_debug(ret, 0, 1); 163 } 164 CRYPTO_THREAD_unlock(global_engine_lock); 165 return ret; 166 } 167 168 /* Iterate to the next/previous "ENGINE" type (NULL = end of the list). */ 169 ENGINE *ENGINE_get_next(ENGINE *e) 170 { 171 ENGINE *ret = NULL; 172 if (e == NULL) { 173 ENGINEerr(ENGINE_F_ENGINE_GET_NEXT, ERR_R_PASSED_NULL_PARAMETER); 174 return 0; 175 } 176 CRYPTO_THREAD_write_lock(global_engine_lock); 177 ret = e->next; 178 if (ret) { 179 /* Return a valid structural reference to the next ENGINE */ 180 ret->struct_ref++; 181 engine_ref_debug(ret, 0, 1); 182 } 183 CRYPTO_THREAD_unlock(global_engine_lock); 184 /* Release the structural reference to the previous ENGINE */ 185 ENGINE_free(e); 186 return ret; 187 } 188 189 ENGINE *ENGINE_get_prev(ENGINE *e) 190 { 191 ENGINE *ret = NULL; 192 if (e == NULL) { 193 ENGINEerr(ENGINE_F_ENGINE_GET_PREV, ERR_R_PASSED_NULL_PARAMETER); 194 return 0; 195 } 196 CRYPTO_THREAD_write_lock(global_engine_lock); 197 ret = e->prev; 198 if (ret) { 199 /* Return a valid structural reference to the next ENGINE */ 200 ret->struct_ref++; 201 engine_ref_debug(ret, 0, 1); 202 } 203 CRYPTO_THREAD_unlock(global_engine_lock); 204 /* Release the structural reference to the previous ENGINE */ 205 ENGINE_free(e); 206 return ret; 207 } 208 209 /* Add another "ENGINE" type into the list. */ 210 int ENGINE_add(ENGINE *e) 211 { 212 int to_return = 1; 213 if (e == NULL) { 214 ENGINEerr(ENGINE_F_ENGINE_ADD, ERR_R_PASSED_NULL_PARAMETER); 215 return 0; 216 } 217 if ((e->id == NULL) || (e->name == NULL)) { 218 ENGINEerr(ENGINE_F_ENGINE_ADD, ENGINE_R_ID_OR_NAME_MISSING); 219 return 0; 220 } 221 CRYPTO_THREAD_write_lock(global_engine_lock); 222 if (!engine_list_add(e)) { 223 ENGINEerr(ENGINE_F_ENGINE_ADD, ENGINE_R_INTERNAL_LIST_ERROR); 224 to_return = 0; 225 } 226 CRYPTO_THREAD_unlock(global_engine_lock); 227 return to_return; 228 } 229 230 /* Remove an existing "ENGINE" type from the array. */ 231 int ENGINE_remove(ENGINE *e) 232 { 233 int to_return = 1; 234 if (e == NULL) { 235 ENGINEerr(ENGINE_F_ENGINE_REMOVE, ERR_R_PASSED_NULL_PARAMETER); 236 return 0; 237 } 238 CRYPTO_THREAD_write_lock(global_engine_lock); 239 if (!engine_list_remove(e)) { 240 ENGINEerr(ENGINE_F_ENGINE_REMOVE, ENGINE_R_INTERNAL_LIST_ERROR); 241 to_return = 0; 242 } 243 CRYPTO_THREAD_unlock(global_engine_lock); 244 return to_return; 245 } 246 247 static void engine_cpy(ENGINE *dest, const ENGINE *src) 248 { 249 dest->id = src->id; 250 dest->name = src->name; 251 #ifndef OPENSSL_NO_RSA 252 dest->rsa_meth = src->rsa_meth; 253 #endif 254 #ifndef OPENSSL_NO_DSA 255 dest->dsa_meth = src->dsa_meth; 256 #endif 257 #ifndef OPENSSL_NO_DH 258 dest->dh_meth = src->dh_meth; 259 #endif 260 #ifndef OPENSSL_NO_EC 261 dest->ec_meth = src->ec_meth; 262 #endif 263 dest->rand_meth = src->rand_meth; 264 dest->ciphers = src->ciphers; 265 dest->digests = src->digests; 266 dest->pkey_meths = src->pkey_meths; 267 dest->destroy = src->destroy; 268 dest->init = src->init; 269 dest->finish = src->finish; 270 dest->ctrl = src->ctrl; 271 dest->load_privkey = src->load_privkey; 272 dest->load_pubkey = src->load_pubkey; 273 dest->cmd_defns = src->cmd_defns; 274 dest->flags = src->flags; 275 } 276 277 ENGINE *ENGINE_by_id(const char *id) 278 { 279 ENGINE *iterator; 280 char *load_dir = NULL; 281 if (id == NULL) { 282 ENGINEerr(ENGINE_F_ENGINE_BY_ID, ERR_R_PASSED_NULL_PARAMETER); 283 return NULL; 284 } 285 if (!RUN_ONCE(&engine_lock_init, do_engine_lock_init)) { 286 ENGINEerr(ENGINE_F_ENGINE_BY_ID, ERR_R_MALLOC_FAILURE); 287 return NULL; 288 } 289 290 CRYPTO_THREAD_write_lock(global_engine_lock); 291 iterator = engine_list_head; 292 while (iterator && (strcmp(id, iterator->id) != 0)) 293 iterator = iterator->next; 294 if (iterator != NULL) { 295 /* 296 * We need to return a structural reference. If this is an ENGINE 297 * type that returns copies, make a duplicate - otherwise increment 298 * the existing ENGINE's reference count. 299 */ 300 if (iterator->flags & ENGINE_FLAGS_BY_ID_COPY) { 301 ENGINE *cp = ENGINE_new(); 302 if (cp == NULL) 303 iterator = NULL; 304 else { 305 engine_cpy(cp, iterator); 306 iterator = cp; 307 } 308 } else { 309 iterator->struct_ref++; 310 engine_ref_debug(iterator, 0, 1); 311 } 312 } 313 CRYPTO_THREAD_unlock(global_engine_lock); 314 if (iterator != NULL) 315 return iterator; 316 /* 317 * Prevent infinite recursion if we're looking for the dynamic engine. 318 */ 319 if (strcmp(id, "dynamic")) { 320 if ((load_dir = ossl_safe_getenv("OPENSSL_ENGINES")) == NULL) 321 load_dir = ENGINESDIR; 322 iterator = ENGINE_by_id("dynamic"); 323 if (!iterator || !ENGINE_ctrl_cmd_string(iterator, "ID", id, 0) || 324 !ENGINE_ctrl_cmd_string(iterator, "DIR_LOAD", "2", 0) || 325 !ENGINE_ctrl_cmd_string(iterator, "DIR_ADD", 326 load_dir, 0) || 327 !ENGINE_ctrl_cmd_string(iterator, "LIST_ADD", "1", 0) || 328 !ENGINE_ctrl_cmd_string(iterator, "LOAD", NULL, 0)) 329 goto notfound; 330 return iterator; 331 } 332 notfound: 333 ENGINE_free(iterator); 334 ENGINEerr(ENGINE_F_ENGINE_BY_ID, ENGINE_R_NO_SUCH_ENGINE); 335 ERR_add_error_data(2, "id=", id); 336 return NULL; 337 /* EEK! Experimental code ends */ 338 } 339 340 int ENGINE_up_ref(ENGINE *e) 341 { 342 int i; 343 if (e == NULL) { 344 ENGINEerr(ENGINE_F_ENGINE_UP_REF, ERR_R_PASSED_NULL_PARAMETER); 345 return 0; 346 } 347 CRYPTO_UP_REF(&e->struct_ref, &i, global_engine_lock); 348 return 1; 349 } 350