crypto/ex_data.c

   1 /*
   2  * Copyright 1995-2016 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 <openssl/lhash.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 static void do_ex_data_init(void)
  39 {
  40     ex_data_lock = CRYPTO_THREAD_lock_new();
  41 }
  42
  43 /*
  44  * Return the EX_CALLBACKS from the |ex_data| array that corresponds to
  45  * a given class.  On success, *holds the lock.*
  46  */
  47 static EX_CALLBACKS *get_and_lock(int class_index)
  48 {
  49     EX_CALLBACKS *ip;
  50
  51     if (class_index < 0 || class_index >= CRYPTO_EX_INDEX__COUNT) {
  52         CRYPTOerr(CRYPTO_F_GET_AND_LOCK, ERR_R_PASSED_INVALID_ARGUMENT);
  53         return NULL;
  54     }
  55
  56     CRYPTO_THREAD_run_once(&ex_data_init, do_ex_data_init);
  57
  58     if (ex_data_lock == NULL) {
  59         /*
  60          * This can happen in normal operation when using CRYPTO_mem_leaks().
  61          * The CRYPTO_mem_leaks() function calls OPENSSL_cleanup() which cleans
  62          * up the locks. Subsequently the BIO that CRYPTO_mem_leaks() uses gets
  63          * freed, which also attempts to free the ex_data. However
  64          * CRYPTO_mem_leaks() ensures that the ex_data is freed early (i.e.
  65          * before OPENSSL_cleanup() is called), so if we get here we can safely
  66          * ignore this operation. We just treat it as an error.
  67          */
  68          return NULL;
  69     }
  70
  71     ip = &ex_data[class_index];
  72     CRYPTO_THREAD_write_lock(ex_data_lock);
  73     return ip;
  74 }
  75
  76 static void cleanup_cb(EX_CALLBACK *funcs)
  77 {
  78     OPENSSL_free(funcs);
  79 }
  80
  81 /*
  82  * Release all "ex_data" state to prevent memory leaks. This can't be made
  83  * thread-safe without overhauling a lot of stuff, and shouldn't really be
  84  * called under potential race-conditions anyway (it's for program shutdown
  85  * after all).
  86  */
  87 void crypto_cleanup_all_ex_data_int(void)
  88 {
  89     int i;
  90
  91     for (i = 0; i < CRYPTO_EX_INDEX__COUNT; ++i) {
  92         EX_CALLBACKS *ip = &ex_data[i];
  93
  94         sk_EX_CALLBACK_pop_free(ip->meth, cleanup_cb);
  95         ip->meth = NULL;
  96     }
  97
  98     CRYPTO_THREAD_lock_free(ex_data_lock);
  99     ex_data_lock = NULL;
 100 }
 101
 102
 103 /*
 104  * Unregister a new index by replacing the callbacks with no-ops.
 105  * Any in-use instances are leaked.
 106  */
 107 static void dummy_new(void *parent, void *ptr, CRYPTO_EX_DATA *ad, int idx,
 108                      long argl, void *argp)
 109 {
 110 }
 111
 112 static void dummy_free(void *parent, void *ptr, CRYPTO_EX_DATA *ad, int idx,
 113                        long argl, void *argp)
 114 {
 115 }
 116
 117 static int dummy_dup(CRYPTO_EX_DATA *to, CRYPTO_EX_DATA *from,
 118                      void *from_d, int idx,
 119                      long argl, void *argp)
 120 {
 121     return 0;
 122 }
 123
 124 int CRYPTO_free_ex_index(int class_index, int idx)
 125 {
 126     EX_CALLBACKS *ip = get_and_lock(class_index);
 127     EX_CALLBACK *a;
 128     int toret = 0;
 129
 130     if (ip == NULL)
 131         return 0;
 132     if (idx < 0 || idx >= sk_EX_CALLBACK_num(ip->meth))
 133         goto err;
 134     a = sk_EX_CALLBACK_value(ip->meth, idx);
 135     if (a == NULL)
 136         goto err;
 137     a->new_func = dummy_new;
 138     a->dup_func = dummy_dup;
 139     a->free_func = dummy_free;
 140     toret = 1;
 141 err:
 142     CRYPTO_THREAD_unlock(ex_data_lock);
 143     return toret;
 144 }
 145
 146 /*
 147  * Register a new index.
 148  */
 149 int CRYPTO_get_ex_new_index(int class_index, long argl, void *argp,
 150                             CRYPTO_EX_new *new_func, CRYPTO_EX_dup *dup_func,
 151                             CRYPTO_EX_free *free_func)
 152 {
 153     int toret = -1;
 154     EX_CALLBACK *a;
 155     EX_CALLBACKS *ip = get_and_lock(class_index);
 156
 157     if (ip == NULL)
 158         return -1;
 159
 160     if (ip->meth == NULL) {
 161         ip->meth = sk_EX_CALLBACK_new_null();
 162         /* We push an initial value on the stack because the SSL
 163          * "app_data" routines use ex_data index zero.  See RT 3710. */
 164         if (ip->meth == NULL
 165             || !sk_EX_CALLBACK_push(ip->meth, NULL)) {
 166             CRYPTOerr(CRYPTO_F_CRYPTO_GET_EX_NEW_INDEX, ERR_R_MALLOC_FAILURE);
 167             goto err;
 168         }
 169     }
 170
 171     a = (EX_CALLBACK *)OPENSSL_malloc(sizeof(*a));
 172     if (a == NULL) {
 173         CRYPTOerr(CRYPTO_F_CRYPTO_GET_EX_NEW_INDEX, ERR_R_MALLOC_FAILURE);
 174         goto err;
 175     }
 176     a->argl = argl;
 177     a->argp = argp;
 178     a->new_func = new_func;
 179     a->dup_func = dup_func;
 180     a->free_func = free_func;
 181
 182     if (!sk_EX_CALLBACK_push(ip->meth, NULL)) {
 183         CRYPTOerr(CRYPTO_F_CRYPTO_GET_EX_NEW_INDEX, ERR_R_MALLOC_FAILURE);
 184         OPENSSL_free(a);
 185         goto err;
 186     }
 187     toret = sk_EX_CALLBACK_num(ip->meth) - 1;
 188     (void)sk_EX_CALLBACK_set(ip->meth, toret, a);
 189
 190  err:
 191     CRYPTO_THREAD_unlock(ex_data_lock);
 192     return toret;
 193 }
 194
 195 /*
 196  * Initialise a new CRYPTO_EX_DATA for use in a particular class - including
 197  * calling new() callbacks for each index in the class used by this variable
 198  * Thread-safe by copying a class's array of "EX_CALLBACK" entries
 199  * in the lock, then using them outside the lock. Note this only applies
 200  * to the global "ex_data" state (ie. class definitions), not 'ad' itself.
 201  */
 202 int CRYPTO_new_ex_data(int class_index, void *obj, CRYPTO_EX_DATA *ad)
 203 {
 204     int mx, i;
 205     void *ptr;
 206     EX_CALLBACK **storage = NULL;
 207     EX_CALLBACK *stack[10];
 208     EX_CALLBACKS *ip = get_and_lock(class_index);
 209
 210     if (ip == NULL)
 211         return 0;
 212
 213     ad->sk = NULL;
 214
 215     mx = sk_EX_CALLBACK_num(ip->meth);
 216     if (mx > 0) {
 217         if (mx < (int)OSSL_NELEM(stack))
 218             storage = stack;
 219         else
 220             storage = OPENSSL_malloc(sizeof(*storage) * mx);
 221         if (storage != NULL)
 222             for (i = 0; i < mx; i++)
 223                 storage[i] = sk_EX_CALLBACK_value(ip->meth, i);
 224     }
 225     CRYPTO_THREAD_unlock(ex_data_lock);
 226
 227     if (mx > 0 && storage == NULL) {
 228         CRYPTOerr(CRYPTO_F_CRYPTO_NEW_EX_DATA, ERR_R_MALLOC_FAILURE);
 229         return 0;
 230     }
 231     for (i = 0; i < mx; i++) {
 232         if (storage[i] && storage[i]->new_func) {
 233             ptr = CRYPTO_get_ex_data(ad, i);
 234             storage[i]->new_func(obj, ptr, ad, i,
 235                                  storage[i]->argl, storage[i]->argp);
 236         }
 237     }
 238     if (storage != stack)
 239         OPENSSL_free(storage);
 240     return 1;
 241 }
 242
 243 /*
 244  * Duplicate a CRYPTO_EX_DATA variable - including calling dup() callbacks
 245  * for each index in the class used by this variable
 246  */
 247 int CRYPTO_dup_ex_data(int class_index, CRYPTO_EX_DATA *to,
 248                        CRYPTO_EX_DATA *from)
 249 {
 250     int mx, j, i;
 251     char *ptr;
 252     EX_CALLBACK *stack[10];
 253     EX_CALLBACK **storage = NULL;
 254     EX_CALLBACKS *ip;
 255
 256     if (from->sk == NULL)
 257         /* Nothing to copy over */
 258         return 1;
 259     if ((ip = get_and_lock(class_index)) == NULL)
 260         return 0;
 261
 262     mx = sk_EX_CALLBACK_num(ip->meth);
 263     j = sk_void_num(from->sk);
 264     if (j < mx)
 265         mx = j;
 266     if (mx > 0) {
 267         if (mx < (int)OSSL_NELEM(stack))
 268             storage = stack;
 269         else
 270             storage = OPENSSL_malloc(sizeof(*storage) * mx);
 271         if (storage != NULL)
 272             for (i = 0; i < mx; i++)
 273                 storage[i] = sk_EX_CALLBACK_value(ip->meth, i);
 274     }
 275     CRYPTO_THREAD_unlock(ex_data_lock);
 276
 277     if (mx > 0 && storage == NULL) {
 278         CRYPTOerr(CRYPTO_F_CRYPTO_DUP_EX_DATA, ERR_R_MALLOC_FAILURE);
 279         return 0;
 280     }
 281
 282     for (i = 0; i < mx; i++) {
 283         ptr = CRYPTO_get_ex_data(from, i);
 284         if (storage[i] && storage[i]->dup_func)
 285             storage[i]->dup_func(to, from, &ptr, i,
 286                                  storage[i]->argl, storage[i]->argp);
 287         CRYPTO_set_ex_data(to, i, ptr);
 288     }
 289     if (storage != stack)
 290         OPENSSL_free(storage);
 291     return 1;
 292 }
 293
 294
 295 /*
 296  * Cleanup a CRYPTO_EX_DATA variable - including calling free() callbacks for
 297  * each index in the class used by this variable
 298  */
 299 void CRYPTO_free_ex_data(int class_index, void *obj, CRYPTO_EX_DATA *ad)
 300 {
 301     int mx, i;
 302     EX_CALLBACKS *ip;
 303     void *ptr;
 304     EX_CALLBACK *stack[10];
 305     EX_CALLBACK **storage = NULL;
 306
 307     if ((ip = get_and_lock(class_index)) == NULL)
 308         return;
 309
 310     mx = sk_EX_CALLBACK_num(ip->meth);
 311     if (mx > 0) {
 312         if (mx < (int)OSSL_NELEM(stack))
 313             storage = stack;
 314         else
 315             storage = OPENSSL_malloc(sizeof(*storage) * mx);
 316         if (storage != NULL)
 317             for (i = 0; i < mx; i++)
 318                 storage[i] = sk_EX_CALLBACK_value(ip->meth, i);
 319     }
 320     CRYPTO_THREAD_unlock(ex_data_lock);
 321
 322     if (mx > 0 && storage == NULL) {
 323         CRYPTOerr(CRYPTO_F_CRYPTO_FREE_EX_DATA, ERR_R_MALLOC_FAILURE);
 324         return;
 325     }
 326     for (i = 0; i < mx; i++) {
 327         if (storage[i] && storage[i]->free_func) {
 328             ptr = CRYPTO_get_ex_data(ad, i);
 329             storage[i]->free_func(obj, ptr, ad, i,
 330                                   storage[i]->argl, storage[i]->argp);
 331         }
 332     }
 333
 334     if (storage != stack)
 335         OPENSSL_free(storage);
 336     sk_void_free(ad->sk);
 337     ad->sk = NULL;
 338 }
 339
 340 /*
 341  * For a given CRYPTO_EX_DATA variable, set the value corresponding to a
 342  * particular index in the class used by this variable
 343  */
 344 int CRYPTO_set_ex_data(CRYPTO_EX_DATA *ad, int idx, void *val)
 345 {
 346     int i;
 347
 348     if (ad->sk == NULL) {
 349         if ((ad->sk = sk_void_new_null()) == NULL) {
 350             CRYPTOerr(CRYPTO_F_CRYPTO_SET_EX_DATA, ERR_R_MALLOC_FAILURE);
 351             return 0;
 352         }
 353     }
 354
 355     for (i = sk_void_num(ad->sk); i <= idx; ++i) {
 356         if (!sk_void_push(ad->sk, NULL)) {
 357             CRYPTOerr(CRYPTO_F_CRYPTO_SET_EX_DATA, ERR_R_MALLOC_FAILURE);
 358             return 0;
 359         }
 360     }
 361     sk_void_set(ad->sk, idx, val);
 362     return 1;
 363 }
 364
 365 /*
 366  * For a given CRYPTO_EX_DATA_ variable, get the value corresponding to a
 367  * particular index in the class used by this variable
 368  */
 369 void *CRYPTO_get_ex_data(const CRYPTO_EX_DATA *ad, int idx)
 370 {
 371     if (ad->sk == NULL || idx >= sk_void_num(ad->sk))
 372         return NULL;
 373     return sk_void_value(ad->sk, idx);
 374 }