1 /* 2 * Copyright 1995-2018 The OpenSSL Project Authors. All Rights Reserved. 3 * 4 * Licensed under the OpenSSL license (the "License"). You may not use 5 * this file except in compliance with the License. You can obtain a copy 6 * in the file LICENSE in the source distribution or at 7 * https://www.openssl.org/source/license.html 8 */ 9 10 #include "internal/cryptlib_int.h" 11 #include "internal/thread_once.h" 12 13 /* 14 * Each structure type (sometimes called a class), that supports 15 * exdata has a stack of callbacks for each instance. 16 */ 17 struct ex_callback_st { 18 long argl; /* Arbitrary long */ 19 void *argp; /* Arbitrary void * */ 20 CRYPTO_EX_new *new_func; 21 CRYPTO_EX_free *free_func; 22 CRYPTO_EX_dup *dup_func; 23 }; 24 25 /* 26 * The state for each class. This could just be a typedef, but 27 * a structure allows future changes. 28 */ 29 typedef struct ex_callbacks_st { 30 STACK_OF(EX_CALLBACK) *meth; 31 } EX_CALLBACKS; 32 33 static EX_CALLBACKS ex_data[CRYPTO_EX_INDEX__COUNT]; 34 35 static CRYPTO_RWLOCK *ex_data_lock = NULL; 36 static CRYPTO_ONCE ex_data_init = CRYPTO_ONCE_STATIC_INIT; 37 38 DEFINE_RUN_ONCE_STATIC(do_ex_data_init) 39 { 40 if (!OPENSSL_init_crypto(0, NULL)) 41 return 0; 42 ex_data_lock = CRYPTO_THREAD_lock_new(); 43 return ex_data_lock != NULL; 44 } 45 46 /* 47 * Return the EX_CALLBACKS from the |ex_data| array that corresponds to 48 * a given class. On success, *holds the lock.* 49 */ 50 static EX_CALLBACKS *get_and_lock(int class_index) 51 { 52 EX_CALLBACKS *ip; 53 54 if (class_index < 0 || class_index >= CRYPTO_EX_INDEX__COUNT) { 55 CRYPTOerr(CRYPTO_F_GET_AND_LOCK, ERR_R_PASSED_INVALID_ARGUMENT); 56 return NULL; 57 } 58 59 if (!RUN_ONCE(&ex_data_init, do_ex_data_init)) { 60 CRYPTOerr(CRYPTO_F_GET_AND_LOCK, ERR_R_MALLOC_FAILURE); 61 return NULL; 62 } 63 64 if (ex_data_lock == NULL) { 65 /* 66 * This can happen in normal operation when using CRYPTO_mem_leaks(). 67 * The CRYPTO_mem_leaks() function calls OPENSSL_cleanup() which cleans 68 * up the locks. Subsequently the BIO that CRYPTO_mem_leaks() uses gets 69 * freed, which also attempts to free the ex_data. However 70 * CRYPTO_mem_leaks() ensures that the ex_data is freed early (i.e. 71 * before OPENSSL_cleanup() is called), so if we get here we can safely 72 * ignore this operation. We just treat it as an error. 73 */ 74 return NULL; 75 } 76 77 ip = &ex_data[class_index]; 78 CRYPTO_THREAD_write_lock(ex_data_lock); 79 return ip; 80 } 81 82 static void cleanup_cb(EX_CALLBACK *funcs) 83 { 84 OPENSSL_free(funcs); 85 } 86 87 /* 88 * Release all "ex_data" state to prevent memory leaks. This can't be made 89 * thread-safe without overhauling a lot of stuff, and shouldn't really be 90 * called under potential race-conditions anyway (it's for program shutdown 91 * after all). 92 */ 93 void crypto_cleanup_all_ex_data_int(void) 94 { 95 int i; 96 97 for (i = 0; i < CRYPTO_EX_INDEX__COUNT; ++i) { 98 EX_CALLBACKS *ip = &ex_data[i]; 99 100 sk_EX_CALLBACK_pop_free(ip->meth, cleanup_cb); 101 ip->meth = NULL; 102 } 103 104 CRYPTO_THREAD_lock_free(ex_data_lock); 105 ex_data_lock = NULL; 106 } 107 108 109 /* 110 * Unregister a new index by replacing the callbacks with no-ops. 111 * Any in-use instances are leaked. 112 */ 113 static void dummy_new(void *parent, void *ptr, CRYPTO_EX_DATA *ad, int idx, 114 long argl, void *argp) 115 { 116 } 117 118 static void dummy_free(void *parent, void *ptr, CRYPTO_EX_DATA *ad, int idx, 119 long argl, void *argp) 120 { 121 } 122 123 static int dummy_dup(CRYPTO_EX_DATA *to, const CRYPTO_EX_DATA *from, 124 void *from_d, int idx, 125 long argl, void *argp) 126 { 127 return 1; 128 } 129 130 int CRYPTO_free_ex_index(int class_index, int idx) 131 { 132 EX_CALLBACKS *ip = get_and_lock(class_index); 133 EX_CALLBACK *a; 134 int toret = 0; 135 136 if (ip == NULL) 137 return 0; 138 if (idx < 0 || idx >= sk_EX_CALLBACK_num(ip->meth)) 139 goto err; 140 a = sk_EX_CALLBACK_value(ip->meth, idx); 141 if (a == NULL) 142 goto err; 143 a->new_func = dummy_new; 144 a->dup_func = dummy_dup; 145 a->free_func = dummy_free; 146 toret = 1; 147 err: 148 CRYPTO_THREAD_unlock(ex_data_lock); 149 return toret; 150 } 151 152 /* 153 * Register a new index. 154 */ 155 int CRYPTO_get_ex_new_index(int class_index, long argl, void *argp, 156 CRYPTO_EX_new *new_func, CRYPTO_EX_dup *dup_func, 157 CRYPTO_EX_free *free_func) 158 { 159 int toret = -1; 160 EX_CALLBACK *a; 161 EX_CALLBACKS *ip = get_and_lock(class_index); 162 163 if (ip == NULL) 164 return -1; 165 166 if (ip->meth == NULL) { 167 ip->meth = sk_EX_CALLBACK_new_null(); 168 /* We push an initial value on the stack because the SSL 169 * "app_data" routines use ex_data index zero. See RT 3710. */ 170 if (ip->meth == NULL 171 || !sk_EX_CALLBACK_push(ip->meth, NULL)) { 172 CRYPTOerr(CRYPTO_F_CRYPTO_GET_EX_NEW_INDEX, ERR_R_MALLOC_FAILURE); 173 goto err; 174 } 175 } 176 177 a = (EX_CALLBACK *)OPENSSL_malloc(sizeof(*a)); 178 if (a == NULL) { 179 CRYPTOerr(CRYPTO_F_CRYPTO_GET_EX_NEW_INDEX, ERR_R_MALLOC_FAILURE); 180 goto err; 181 } 182 a->argl = argl; 183 a->argp = argp; 184 a->new_func = new_func; 185 a->dup_func = dup_func; 186 a->free_func = free_func; 187 188 if (!sk_EX_CALLBACK_push(ip->meth, NULL)) { 189 CRYPTOerr(CRYPTO_F_CRYPTO_GET_EX_NEW_INDEX, ERR_R_MALLOC_FAILURE); 190 OPENSSL_free(a); 191 goto err; 192 } 193 toret = sk_EX_CALLBACK_num(ip->meth) - 1; 194 (void)sk_EX_CALLBACK_set(ip->meth, toret, a); 195 196 err: 197 CRYPTO_THREAD_unlock(ex_data_lock); 198 return toret; 199 } 200 201 /* 202 * Initialise a new CRYPTO_EX_DATA for use in a particular class - including 203 * calling new() callbacks for each index in the class used by this variable 204 * Thread-safe by copying a class's array of "EX_CALLBACK" entries 205 * in the lock, then using them outside the lock. Note this only applies 206 * to the global "ex_data" state (ie. class definitions), not 'ad' itself. 207 */ 208 int CRYPTO_new_ex_data(int class_index, void *obj, CRYPTO_EX_DATA *ad) 209 { 210 int mx, i; 211 void *ptr; 212 EX_CALLBACK **storage = NULL; 213 EX_CALLBACK *stack[10]; 214 EX_CALLBACKS *ip = get_and_lock(class_index); 215 216 if (ip == NULL) 217 return 0; 218 219 ad->sk = NULL; 220 221 mx = sk_EX_CALLBACK_num(ip->meth); 222 if (mx > 0) { 223 if (mx < (int)OSSL_NELEM(stack)) 224 storage = stack; 225 else 226 storage = OPENSSL_malloc(sizeof(*storage) * mx); 227 if (storage != NULL) 228 for (i = 0; i < mx; i++) 229 storage[i] = sk_EX_CALLBACK_value(ip->meth, i); 230 } 231 CRYPTO_THREAD_unlock(ex_data_lock); 232 233 if (mx > 0 && storage == NULL) { 234 CRYPTOerr(CRYPTO_F_CRYPTO_NEW_EX_DATA, ERR_R_MALLOC_FAILURE); 235 return 0; 236 } 237 for (i = 0; i < mx; i++) { 238 if (storage[i] && storage[i]->new_func) { 239 ptr = CRYPTO_get_ex_data(ad, i); 240 storage[i]->new_func(obj, ptr, ad, i, 241 storage[i]->argl, storage[i]->argp); 242 } 243 } 244 if (storage != stack) 245 OPENSSL_free(storage); 246 return 1; 247 } 248 249 /* 250 * Duplicate a CRYPTO_EX_DATA variable - including calling dup() callbacks 251 * for each index in the class used by this variable 252 */ 253 int CRYPTO_dup_ex_data(int class_index, CRYPTO_EX_DATA *to, 254 const CRYPTO_EX_DATA *from) 255 { 256 int mx, j, i; 257 void *ptr; 258 EX_CALLBACK *stack[10]; 259 EX_CALLBACK **storage = NULL; 260 EX_CALLBACKS *ip; 261 int toret = 0; 262 263 if (from->sk == NULL) 264 /* Nothing to copy over */ 265 return 1; 266 if ((ip = get_and_lock(class_index)) == NULL) 267 return 0; 268 269 mx = sk_EX_CALLBACK_num(ip->meth); 270 j = sk_void_num(from->sk); 271 if (j < mx) 272 mx = j; 273 if (mx > 0) { 274 if (mx < (int)OSSL_NELEM(stack)) 275 storage = stack; 276 else 277 storage = OPENSSL_malloc(sizeof(*storage) * mx); 278 if (storage != NULL) 279 for (i = 0; i < mx; i++) 280 storage[i] = sk_EX_CALLBACK_value(ip->meth, i); 281 } 282 CRYPTO_THREAD_unlock(ex_data_lock); 283 284 if (mx == 0) 285 return 1; 286 if (storage == NULL) { 287 CRYPTOerr(CRYPTO_F_CRYPTO_DUP_EX_DATA, ERR_R_MALLOC_FAILURE); 288 return 0; 289 } 290 /* 291 * Make sure the ex_data stack is at least |mx| elements long to avoid 292 * issues in the for loop that follows; so go get the |mx|'th element 293 * (if it does not exist CRYPTO_get_ex_data() returns NULL), and assign 294 * to itself. This is normally a no-op; but ensures the stack is the 295 * proper size 296 */ 297 if (!CRYPTO_set_ex_data(to, mx - 1, CRYPTO_get_ex_data(to, mx - 1))) 298 goto err; 299 300 for (i = 0; i < mx; i++) { 301 ptr = CRYPTO_get_ex_data(from, i); 302 if (storage[i] && storage[i]->dup_func) 303 if (!storage[i]->dup_func(to, from, &ptr, i, 304 storage[i]->argl, storage[i]->argp)) 305 goto err; 306 CRYPTO_set_ex_data(to, i, ptr); 307 } 308 toret = 1; 309 err: 310 if (storage != stack) 311 OPENSSL_free(storage); 312 return toret; 313 } 314 315 316 /* 317 * Cleanup a CRYPTO_EX_DATA variable - including calling free() callbacks for 318 * each index in the class used by this variable 319 */ 320 void CRYPTO_free_ex_data(int class_index, void *obj, CRYPTO_EX_DATA *ad) 321 { 322 int mx, i; 323 EX_CALLBACKS *ip; 324 void *ptr; 325 EX_CALLBACK *f; 326 EX_CALLBACK *stack[10]; 327 EX_CALLBACK **storage = NULL; 328 329 if ((ip = get_and_lock(class_index)) == NULL) 330 goto err; 331 332 mx = sk_EX_CALLBACK_num(ip->meth); 333 if (mx > 0) { 334 if (mx < (int)OSSL_NELEM(stack)) 335 storage = stack; 336 else 337 storage = OPENSSL_malloc(sizeof(*storage) * mx); 338 if (storage != NULL) 339 for (i = 0; i < mx; i++) 340 storage[i] = sk_EX_CALLBACK_value(ip->meth, i); 341 } 342 CRYPTO_THREAD_unlock(ex_data_lock); 343 344 for (i = 0; i < mx; i++) { 345 if (storage != NULL) 346 f = storage[i]; 347 else { 348 CRYPTO_THREAD_write_lock(ex_data_lock); 349 f = sk_EX_CALLBACK_value(ip->meth, i); 350 CRYPTO_THREAD_unlock(ex_data_lock); 351 } 352 if (f != NULL && f->free_func != NULL) { 353 ptr = CRYPTO_get_ex_data(ad, i); 354 f->free_func(obj, ptr, ad, i, f->argl, f->argp); 355 } 356 } 357 358 if (storage != stack) 359 OPENSSL_free(storage); 360 err: 361 sk_void_free(ad->sk); 362 ad->sk = NULL; 363 } 364 365 /* 366 * For a given CRYPTO_EX_DATA variable, set the value corresponding to a 367 * particular index in the class used by this variable 368 */ 369 int CRYPTO_set_ex_data(CRYPTO_EX_DATA *ad, int idx, void *val) 370 { 371 int i; 372 373 if (ad->sk == NULL) { 374 if ((ad->sk = sk_void_new_null()) == NULL) { 375 CRYPTOerr(CRYPTO_F_CRYPTO_SET_EX_DATA, ERR_R_MALLOC_FAILURE); 376 return 0; 377 } 378 } 379 380 for (i = sk_void_num(ad->sk); i <= idx; ++i) { 381 if (!sk_void_push(ad->sk, NULL)) { 382 CRYPTOerr(CRYPTO_F_CRYPTO_SET_EX_DATA, ERR_R_MALLOC_FAILURE); 383 return 0; 384 } 385 } 386 sk_void_set(ad->sk, idx, val); 387 return 1; 388 } 389 390 /* 391 * For a given CRYPTO_EX_DATA_ variable, get the value corresponding to a 392 * particular index in the class used by this variable 393 */ 394 void *CRYPTO_get_ex_data(const CRYPTO_EX_DATA *ad, int idx) 395 { 396 if (ad->sk == NULL || idx >= sk_void_num(ad->sk)) 397 return NULL; 398 return sk_void_value(ad->sk, idx); 399 } 400