/* $OpenBSD: ex_data.c,v 1.20 2018/03/17 16:20:01 beck Exp $ */ /* * Overhaul notes; * * This code is now *mostly* thread-safe. It is now easier to understand in what * ways it is safe and in what ways it is not, which is an improvement. Firstly, * all per-class stacks and index-counters for ex_data are stored in the same * global LHASH table (keyed by class). This hash table uses locking for all * access with the exception of CRYPTO_cleanup_all_ex_data(), which must only be * called when no other threads can possibly race against it (even if it was * locked, the race would mean it's possible the hash table might have been * recreated after the cleanup). As classes can only be added to the hash table, * and within each class, the stack of methods can only be incremented, the * locking mechanics are simpler than they would otherwise be. For example, the * new/dup/free ex_data functions will lock the hash table, copy the method * pointers it needs from the relevant class, then unlock the hash table before * actually applying those method pointers to the task of the new/dup/free * operations. As they can't be removed from the method-stack, only * supplemented, there's no race conditions associated with using them outside * the lock. The get/set_ex_data functions are not locked because they do not * involve this global state at all - they operate directly with a previously * obtained per-class method index and a particular "ex_data" variable. These * variables are usually instantiated per-context (eg. each RSA structure has * one) so locking on read/write access to that variable can be locked locally * if required (eg. using the "RSA" lock to synchronise access to a * per-RSA-structure ex_data variable if required). * [Geoff] */ /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) * All rights reserved. * * This package is an SSL implementation written * by Eric Young (eay@cryptsoft.com). * The implementation was written so as to conform with Netscapes SSL. * * This library is free for commercial and non-commercial use as long as * the following conditions are aheared to. The following conditions * apply to all code found in this distribution, be it the RC4, RSA, * lhash, DES, etc., code; not just the SSL code. The SSL documentation * included with this distribution is covered by the same copyright terms * except that the holder is Tim Hudson (tjh@cryptsoft.com). * * Copyright remains Eric Young's, and as such any Copyright notices in * the code are not to be removed. * If this package is used in a product, Eric Young should be given attribution * as the author of the parts of the library used. * This can be in the form of a textual message at program startup or * in documentation (online or textual) provided with the package. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * "This product includes cryptographic software written by * Eric Young (eay@cryptsoft.com)" * The word 'cryptographic' can be left out if the rouines from the library * being used are not cryptographic related :-). * 4. If you include any Windows specific code (or a derivative thereof) from * the apps directory (application code) you must include an acknowledgement: * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" * * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * The licence and distribution terms for any publically available version or * derivative of this code cannot be changed. i.e. this code cannot simply be * copied and put under another distribution licence * [including the GNU Public Licence.] */ /* ==================================================================== * Copyright (c) 1998-2001 The OpenSSL Project. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * * 3. All advertising materials mentioning features or use of this * software must display the following acknowledgment: * "This product includes software developed by the OpenSSL Project * for use in the OpenSSL Toolkit. (http://www.openssl.org/)" * * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to * endorse or promote products derived from this software without * prior written permission. For written permission, please contact * openssl-core@openssl.org. * * 5. Products derived from this software may not be called "OpenSSL" * nor may "OpenSSL" appear in their names without prior written * permission of the OpenSSL Project. * * 6. Redistributions of any form whatsoever must retain the following * acknowledgment: * "This product includes software developed by the OpenSSL Project * for use in the OpenSSL Toolkit (http://www.openssl.org/)" * * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED * OF THE POSSIBILITY OF SUCH DAMAGE. * ==================================================================== * * This product includes cryptographic software written by Eric Young * (eay@cryptsoft.com). This product includes software written by Tim * Hudson (tjh@cryptsoft.com). * */ #include <openssl/err.h> #include <openssl/lhash.h> /* What an "implementation of ex_data functionality" looks like */ struct st_CRYPTO_EX_DATA_IMPL { /*********************/ /* GLOBAL OPERATIONS */ /* Return a new class index */ int (*cb_new_class)(void); /* Cleanup all state used by the implementation */ void (*cb_cleanup)(void); /************************/ /* PER-CLASS OPERATIONS */ /* Get a new method index within a class */ int (*cb_get_new_index)(int class_index, long argl, void *argp, CRYPTO_EX_new *new_func, CRYPTO_EX_dup *dup_func, CRYPTO_EX_free *free_func); /* Initialise a new CRYPTO_EX_DATA of a given class */ int (*cb_new_ex_data)(int class_index, void *obj, CRYPTO_EX_DATA *ad); /* Duplicate a CRYPTO_EX_DATA of a given class onto a copy */ int (*cb_dup_ex_data)(int class_index, CRYPTO_EX_DATA *to, CRYPTO_EX_DATA *from); /* Cleanup a CRYPTO_EX_DATA of a given class */ void (*cb_free_ex_data)(int class_index, void *obj, CRYPTO_EX_DATA *ad); }; /* The implementation we use at run-time */ static const CRYPTO_EX_DATA_IMPL *impl = NULL; /* To call "impl" functions, use this macro rather than referring to 'impl' directly, eg. * EX_IMPL(get_new_index)(...); */ #define EX_IMPL(a) impl->cb_##a /* Predeclare the "default" ex_data implementation */ static int int_new_class(void); static void int_cleanup(void); static int int_get_new_index(int class_index, long argl, void *argp, CRYPTO_EX_new *new_func, CRYPTO_EX_dup *dup_func, CRYPTO_EX_free *free_func); static int int_new_ex_data(int class_index, void *obj, CRYPTO_EX_DATA *ad); static int int_dup_ex_data(int class_index, CRYPTO_EX_DATA *to, CRYPTO_EX_DATA *from); static void int_free_ex_data(int class_index, void *obj, CRYPTO_EX_DATA *ad); static CRYPTO_EX_DATA_IMPL impl_default = { int_new_class, int_cleanup, int_get_new_index, int_new_ex_data, int_dup_ex_data, int_free_ex_data }; /* Internal function that checks whether "impl" is set and if not, sets it to * the default. */ static void impl_check(void) { CRYPTO_w_lock(CRYPTO_LOCK_EX_DATA); if (!impl) impl = &impl_default; CRYPTO_w_unlock(CRYPTO_LOCK_EX_DATA); } /* A macro wrapper for impl_check that first uses a non-locked test before * invoking the function (which checks again inside a lock). */ #define IMPL_CHECK if(!impl) impl_check(); /* API functions to get/set the "ex_data" implementation */ const CRYPTO_EX_DATA_IMPL * CRYPTO_get_ex_data_implementation(void) { IMPL_CHECK return impl; } int CRYPTO_set_ex_data_implementation(const CRYPTO_EX_DATA_IMPL *i) { int toret = 0; CRYPTO_w_lock(CRYPTO_LOCK_EX_DATA); if (!impl) { impl = i; toret = 1; } CRYPTO_w_unlock(CRYPTO_LOCK_EX_DATA); return toret; } /****************************************************************************/ /* Interal (default) implementation of "ex_data" support. API functions are * further down. */ /* The type that represents what each "class" used to implement locally. A STACK * of CRYPTO_EX_DATA_FUNCS plus a index-counter. The 'class_index' is the global * value representing the class that is used to distinguish these items. */ typedef struct st_ex_class_item { int class_index; STACK_OF(CRYPTO_EX_DATA_FUNCS) *meth; int meth_num; } EX_CLASS_ITEM; /* When assigning new class indexes, this is our counter */ static int ex_class = CRYPTO_EX_INDEX_USER; /* The global hash table of EX_CLASS_ITEM items */ DECLARE_LHASH_OF(EX_CLASS_ITEM); static LHASH_OF(EX_CLASS_ITEM) *ex_data = NULL; /* The callbacks required in the "ex_data" hash table */ static unsigned long ex_class_item_hash(const EX_CLASS_ITEM *a) { return a->class_index; } static IMPLEMENT_LHASH_HASH_FN(ex_class_item, EX_CLASS_ITEM) static int ex_class_item_cmp(const EX_CLASS_ITEM *a, const EX_CLASS_ITEM *b) { return a->class_index - b->class_index; } static IMPLEMENT_LHASH_COMP_FN(ex_class_item, EX_CLASS_ITEM) /* Internal functions used by the "impl_default" implementation to access the * state */ static int ex_data_check(void) { int toret = 1; CRYPTO_w_lock(CRYPTO_LOCK_EX_DATA); if (!ex_data && (ex_data = lh_EX_CLASS_ITEM_new()) == NULL) toret = 0; CRYPTO_w_unlock(CRYPTO_LOCK_EX_DATA); return toret; } /* This macros helps reduce the locking from repeated checks because the * ex_data_check() function checks ex_data again inside a lock. */ #define EX_DATA_CHECK(iffail) if(!ex_data && !ex_data_check()) {iffail} /* This "inner" callback is used by the callback function that follows it */ static void def_cleanup_util_cb(CRYPTO_EX_DATA_FUNCS *funcs) { free(funcs); } /* This callback is used in lh_doall to destroy all EX_CLASS_ITEM values from * "ex_data" prior to the ex_data hash table being itself destroyed. Doesn't do * any locking. */ static void def_cleanup_cb(void *a_void) { EX_CLASS_ITEM *item = (EX_CLASS_ITEM *)a_void; sk_CRYPTO_EX_DATA_FUNCS_pop_free(item->meth, def_cleanup_util_cb); free(item); } /* Return the EX_CLASS_ITEM from the "ex_data" hash table that corresponds to a * given class. Handles locking. */ static EX_CLASS_ITEM * def_get_class(int class_index) { EX_CLASS_ITEM d, *p, *gen; EX_DATA_CHECK(return NULL;) d.class_index = class_index; if (!OPENSSL_init_crypto(0, NULL)) return NULL; CRYPTO_w_lock(CRYPTO_LOCK_EX_DATA); p = lh_EX_CLASS_ITEM_retrieve(ex_data, &d); if (!p) { gen = malloc(sizeof(EX_CLASS_ITEM)); if (gen) { gen->class_index = class_index; gen->meth_num = 0; gen->meth = sk_CRYPTO_EX_DATA_FUNCS_new_null(); if (!gen->meth) free(gen); else { /* Because we're inside the ex_data lock, the * return value from the insert will be NULL */ (void)lh_EX_CLASS_ITEM_insert(ex_data, gen); p = gen; } } } CRYPTO_w_unlock(CRYPTO_LOCK_EX_DATA); if (!p) CRYPTOerror(ERR_R_MALLOC_FAILURE); return p; } /* Add a new method to the given EX_CLASS_ITEM and return the corresponding * index (or -1 for error). Handles locking. */ static int def_add_index(EX_CLASS_ITEM *item, long argl, void *argp, CRYPTO_EX_new *new_func, CRYPTO_EX_dup *dup_func, CRYPTO_EX_free *free_func) { int toret = -1; CRYPTO_EX_DATA_FUNCS *a = malloc(sizeof(CRYPTO_EX_DATA_FUNCS)); if (!a) { CRYPTOerror(ERR_R_MALLOC_FAILURE); return -1; } a->argl = argl; a->argp = argp; a->new_func = new_func; a->dup_func = dup_func; a->free_func = free_func; CRYPTO_w_lock(CRYPTO_LOCK_EX_DATA); while (sk_CRYPTO_EX_DATA_FUNCS_num(item->meth) <= item->meth_num) { if (!sk_CRYPTO_EX_DATA_FUNCS_push(item->meth, NULL)) { CRYPTOerror(ERR_R_MALLOC_FAILURE); free(a); goto err; } } toret = item->meth_num++; (void)sk_CRYPTO_EX_DATA_FUNCS_set(item->meth, toret, a); err: CRYPTO_w_unlock(CRYPTO_LOCK_EX_DATA); return toret; } /**************************************************************/ /* The functions in the default CRYPTO_EX_DATA_IMPL structure */ static int int_new_class(void) { int toret; CRYPTO_w_lock(CRYPTO_LOCK_EX_DATA); toret = ex_class++; CRYPTO_w_unlock(CRYPTO_LOCK_EX_DATA); return toret; } static void int_cleanup(void) { EX_DATA_CHECK(return;) lh_EX_CLASS_ITEM_doall(ex_data, def_cleanup_cb); lh_EX_CLASS_ITEM_free(ex_data); ex_data = NULL; impl = NULL; } static int int_get_new_index(int class_index, long argl, void *argp, CRYPTO_EX_new *new_func, CRYPTO_EX_dup *dup_func, CRYPTO_EX_free *free_func) { EX_CLASS_ITEM *item = def_get_class(class_index); if (!item) return -1; return def_add_index(item, argl, argp, new_func, dup_func, free_func); } /* Thread-safe by copying a class's array of "CRYPTO_EX_DATA_FUNCS" entries in * the lock, then using them outside the lock. NB: Thread-safety only applies to * the global "ex_data" state (ie. class definitions), not thread-safe on 'ad' * itself. */ static int int_new_ex_data(int class_index, void *obj, CRYPTO_EX_DATA *ad) { int mx, i; void *ptr; CRYPTO_EX_DATA_FUNCS **storage = NULL; EX_CLASS_ITEM *item = def_get_class(class_index); if (!item) /* error is already set */ return 0; ad->sk = NULL; CRYPTO_r_lock(CRYPTO_LOCK_EX_DATA); mx = sk_CRYPTO_EX_DATA_FUNCS_num(item->meth); if (mx > 0) { storage = reallocarray(NULL, mx, sizeof(CRYPTO_EX_DATA_FUNCS*)); if (!storage) goto skip; for (i = 0; i < mx; i++) storage[i] = sk_CRYPTO_EX_DATA_FUNCS_value( item->meth, i); } skip: CRYPTO_r_unlock(CRYPTO_LOCK_EX_DATA); if ((mx > 0) && !storage) { CRYPTOerror(ERR_R_MALLOC_FAILURE); return 0; } for (i = 0; i < mx; i++) { if (storage[i] && storage[i]->new_func) { ptr = CRYPTO_get_ex_data(ad, i); storage[i]->new_func(obj, ptr, ad, i, storage[i]->argl, storage[i]->argp); } } free(storage); return 1; } /* Same thread-safety notes as for "int_new_ex_data" */ static int int_dup_ex_data(int class_index, CRYPTO_EX_DATA *to, CRYPTO_EX_DATA *from) { int mx, j, i; char *ptr; CRYPTO_EX_DATA_FUNCS **storage = NULL; EX_CLASS_ITEM *item; if (!from->sk) /* 'to' should be "blank" which *is* just like 'from' */ return 1; if ((item = def_get_class(class_index)) == NULL) return 0; CRYPTO_r_lock(CRYPTO_LOCK_EX_DATA); mx = sk_CRYPTO_EX_DATA_FUNCS_num(item->meth); j = sk_void_num(from->sk); if (j < mx) mx = j; if (mx > 0) { storage = reallocarray(NULL, mx, sizeof(CRYPTO_EX_DATA_FUNCS*)); if (!storage) goto skip; for (i = 0; i < mx; i++) storage[i] = sk_CRYPTO_EX_DATA_FUNCS_value( item->meth, i); } skip: CRYPTO_r_unlock(CRYPTO_LOCK_EX_DATA); if ((mx > 0) && !storage) { CRYPTOerror(ERR_R_MALLOC_FAILURE); return 0; } for (i = 0; i < mx; i++) { ptr = CRYPTO_get_ex_data(from, i); if (storage[i] && storage[i]->dup_func) storage[i]->dup_func(to, from, &ptr, i, storage[i]->argl, storage[i]->argp); CRYPTO_set_ex_data(to, i, ptr); } free(storage); return 1; } /* Same thread-safety notes as for "int_new_ex_data" */ static void int_free_ex_data(int class_index, void *obj, CRYPTO_EX_DATA *ad) { int mx, i; EX_CLASS_ITEM *item; void *ptr; CRYPTO_EX_DATA_FUNCS **storage = NULL; if ((item = def_get_class(class_index)) == NULL) return; CRYPTO_r_lock(CRYPTO_LOCK_EX_DATA); mx = sk_CRYPTO_EX_DATA_FUNCS_num(item->meth); if (mx > 0) { storage = reallocarray(NULL, mx, sizeof(CRYPTO_EX_DATA_FUNCS*)); if (!storage) goto skip; for (i = 0; i < mx; i++) storage[i] = sk_CRYPTO_EX_DATA_FUNCS_value( item->meth, i); } skip: CRYPTO_r_unlock(CRYPTO_LOCK_EX_DATA); if ((mx > 0) && !storage) { CRYPTOerror(ERR_R_MALLOC_FAILURE); return; } for (i = 0; i < mx; i++) { if (storage[i] && storage[i]->free_func) { ptr = CRYPTO_get_ex_data(ad, i); storage[i]->free_func(obj, ptr, ad, i, storage[i]->argl, storage[i]->argp); } } free(storage); if (ad->sk) { sk_void_free(ad->sk); ad->sk = NULL; } } /********************************************************************/ /* API functions that defer all "state" operations to the "ex_data" * implementation we have set. */ /* Obtain an index for a new class (not the same as getting a new index within * an existing class - this is actually getting a new *class*) */ int CRYPTO_ex_data_new_class(void) { IMPL_CHECK return EX_IMPL(new_class)(); } /* Release all "ex_data" state to prevent memory leaks. This can't be made * thread-safe without overhauling a lot of stuff, and shouldn't really be * called under potential race-conditions anyway (it's for program shutdown * after all). */ void CRYPTO_cleanup_all_ex_data(void) { IMPL_CHECK EX_IMPL(cleanup)(); } /* Inside an existing class, get/register a new index. */ int CRYPTO_get_ex_new_index(int class_index, long argl, void *argp, CRYPTO_EX_new *new_func, CRYPTO_EX_dup *dup_func, CRYPTO_EX_free *free_func) { int ret = -1; IMPL_CHECK ret = EX_IMPL(get_new_index)(class_index, argl, argp, new_func, dup_func, free_func); return ret; } /* Initialise a new CRYPTO_EX_DATA for use in a particular class - including * calling new() callbacks for each index in the class used by this variable */ int CRYPTO_new_ex_data(int class_index, void *obj, CRYPTO_EX_DATA *ad) { IMPL_CHECK return EX_IMPL(new_ex_data)(class_index, obj, ad); } /* Duplicate a CRYPTO_EX_DATA variable - including calling dup() callbacks for * each index in the class used by this variable */ int CRYPTO_dup_ex_data(int class_index, CRYPTO_EX_DATA *to, CRYPTO_EX_DATA *from) { IMPL_CHECK return EX_IMPL(dup_ex_data)(class_index, to, from); } /* Cleanup a CRYPTO_EX_DATA variable - including calling free() callbacks for * each index in the class used by this variable */ void CRYPTO_free_ex_data(int class_index, void *obj, CRYPTO_EX_DATA *ad) { IMPL_CHECK EX_IMPL(free_ex_data)(class_index, obj, ad); } /* For a given CRYPTO_EX_DATA variable, set the value corresponding to a * particular index in the class used by this variable */ int CRYPTO_set_ex_data(CRYPTO_EX_DATA *ad, int idx, void *val) { int i; if (ad->sk == NULL) { if ((ad->sk = sk_void_new_null()) == NULL) { CRYPTOerror(ERR_R_MALLOC_FAILURE); return (0); } } i = sk_void_num(ad->sk); while (i <= idx) { if (!sk_void_push(ad->sk, NULL)) { CRYPTOerror(ERR_R_MALLOC_FAILURE); return (0); } i++; } sk_void_set(ad->sk, idx, val); return (1); } /* For a given CRYPTO_EX_DATA_ variable, get the value corresponding to a * particular index in the class used by this variable */ void * CRYPTO_get_ex_data(const CRYPTO_EX_DATA *ad, int idx) { if (ad->sk == NULL) return (0); else if (idx >= sk_void_num(ad->sk)) return (0); else return (sk_void_value(ad->sk, idx)); }
