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      1 /* ====================================================================
      2  * Copyright (c) 2001 The OpenSSL Project.  All rights reserved.
      3  *
      4  * Redistribution and use in source and binary forms, with or without
      5  * modification, are permitted provided that the following conditions
      6  * are met:
      7  *
      8  * 1. Redistributions of source code must retain the above copyright
      9  *    notice, this list of conditions and the following disclaimer.
     10  *
     11  * 2. Redistributions in binary form must reproduce the above copyright
     12  *    notice, this list of conditions and the following disclaimer in
     13  *    the documentation and/or other materials provided with the
     14  *    distribution.
     15  *
     16  * 3. All advertising materials mentioning features or use of this
     17  *    software must display the following acknowledgment:
     18  *    "This product includes software developed by the OpenSSL Project
     19  *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
     20  *
     21  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
     22  *    endorse or promote products derived from this software without
     23  *    prior written permission. For written permission, please contact
     24  *    licensing (at) OpenSSL.org.
     25  *
     26  * 5. Products derived from this software may not be called "OpenSSL"
     27  *    nor may "OpenSSL" appear in their names without prior written
     28  *    permission of the OpenSSL Project.
     29  *
     30  * 6. Redistributions of any form whatsoever must retain the following
     31  *    acknowledgment:
     32  *    "This product includes software developed by the OpenSSL Project
     33  *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
     34  *
     35  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
     36  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     37  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     38  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
     39  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     40  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     41  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
     42  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     43  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
     44  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     45  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
     46  * OF THE POSSIBILITY OF SUCH DAMAGE.
     47  * ====================================================================
     48  *
     49  * This product includes cryptographic software written by Eric Young
     50  * (eay (at) cryptsoft.com).  This product includes software written by Tim
     51  * Hudson (tjh (at) cryptsoft.com).
     52  *
     53  */
     54 
     55 #include "cryptlib.h"
     56 #include <openssl/evp.h>
     57 #include <openssl/lhash.h>
     58 #include "eng_int.h"
     59 
     60 /* The type of the items in the table */
     61 typedef struct st_engine_pile
     62 	{
     63 	/* The 'nid' of this algorithm/mode */
     64 	int nid;
     65 	/* ENGINEs that implement this algorithm/mode. */
     66 	STACK_OF(ENGINE) *sk;
     67 	/* The default ENGINE to perform this algorithm/mode. */
     68 	ENGINE *funct;
     69 	/* Zero if 'sk' is newer than the cached 'funct', non-zero otherwise */
     70 	int uptodate;
     71 	} ENGINE_PILE;
     72 
     73 /* The type exposed in eng_int.h */
     74 struct st_engine_table
     75 	{
     76 	LHASH piles;
     77 	}; /* ENGINE_TABLE */
     78 
     79 /* Global flags (ENGINE_TABLE_FLAG_***). */
     80 static unsigned int table_flags = 0;
     81 
     82 /* API function manipulating 'table_flags' */
     83 unsigned int ENGINE_get_table_flags(void)
     84 	{
     85 	return table_flags;
     86 	}
     87 void ENGINE_set_table_flags(unsigned int flags)
     88 	{
     89 	table_flags = flags;
     90 	}
     91 
     92 /* Internal functions for the "piles" hash table */
     93 static unsigned long engine_pile_hash(const ENGINE_PILE *c)
     94 	{
     95 	return c->nid;
     96 	}
     97 static int engine_pile_cmp(const ENGINE_PILE *a, const ENGINE_PILE *b)
     98 	{
     99 	return a->nid - b->nid;
    100 	}
    101 static IMPLEMENT_LHASH_HASH_FN(engine_pile_hash, const ENGINE_PILE *)
    102 static IMPLEMENT_LHASH_COMP_FN(engine_pile_cmp, const ENGINE_PILE *)
    103 static int int_table_check(ENGINE_TABLE **t, int create)
    104 	{
    105 	LHASH *lh;
    106 	if(*t) return 1;
    107 	if(!create) return 0;
    108 	if((lh = lh_new(LHASH_HASH_FN(engine_pile_hash),
    109 			LHASH_COMP_FN(engine_pile_cmp))) == NULL)
    110 		return 0;
    111 	*t = (ENGINE_TABLE *)lh;
    112 	return 1;
    113 	}
    114 
    115 /* Privately exposed (via eng_int.h) functions for adding and/or removing
    116  * ENGINEs from the implementation table */
    117 int engine_table_register(ENGINE_TABLE **table, ENGINE_CLEANUP_CB *cleanup,
    118 		ENGINE *e, const int *nids, int num_nids, int setdefault)
    119 	{
    120 	int ret = 0, added = 0;
    121 	ENGINE_PILE tmplate, *fnd;
    122 	CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
    123 	if(!(*table))
    124 		added = 1;
    125 	if(!int_table_check(table, 1))
    126 		goto end;
    127 	if(added)
    128 		/* The cleanup callback needs to be added */
    129 		engine_cleanup_add_first(cleanup);
    130 	while(num_nids--)
    131 		{
    132 		tmplate.nid = *nids;
    133 		fnd = lh_retrieve(&(*table)->piles, &tmplate);
    134 		if(!fnd)
    135 			{
    136 			fnd = OPENSSL_malloc(sizeof(ENGINE_PILE));
    137 			if(!fnd) goto end;
    138 			fnd->uptodate = 1;
    139 			fnd->nid = *nids;
    140 			fnd->sk = sk_ENGINE_new_null();
    141 			if(!fnd->sk)
    142 				{
    143 				OPENSSL_free(fnd);
    144 				goto end;
    145 				}
    146 			fnd->funct = NULL;
    147 			lh_insert(&(*table)->piles, fnd);
    148 			}
    149 		/* A registration shouldn't add duplciate entries */
    150 		(void)sk_ENGINE_delete_ptr(fnd->sk, e);
    151 		/* if 'setdefault', this ENGINE goes to the head of the list */
    152 		if(!sk_ENGINE_push(fnd->sk, e))
    153 			goto end;
    154 		/* "touch" this ENGINE_PILE */
    155 		fnd->uptodate = 0;
    156 		if(setdefault)
    157 			{
    158 			if(!engine_unlocked_init(e))
    159 				{
    160 				ENGINEerr(ENGINE_F_ENGINE_TABLE_REGISTER,
    161 						ENGINE_R_INIT_FAILED);
    162 				goto end;
    163 				}
    164 			if(fnd->funct)
    165 				engine_unlocked_finish(fnd->funct, 0);
    166 			fnd->funct = e;
    167 			fnd->uptodate = 1;
    168 			}
    169 		nids++;
    170 		}
    171 	ret = 1;
    172 end:
    173 	CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
    174 	return ret;
    175 	}
    176 static void int_unregister_cb(ENGINE_PILE *pile, ENGINE *e)
    177 	{
    178 	int n;
    179 	/* Iterate the 'c->sk' stack removing any occurance of 'e' */
    180 	while((n = sk_ENGINE_find(pile->sk, e)) >= 0)
    181 		{
    182 		(void)sk_ENGINE_delete(pile->sk, n);
    183 		pile->uptodate = 0;
    184 		}
    185 	if(pile->funct == e)
    186 		{
    187 		engine_unlocked_finish(e, 0);
    188 		pile->funct = NULL;
    189 		}
    190 	}
    191 static IMPLEMENT_LHASH_DOALL_ARG_FN(int_unregister_cb,ENGINE_PILE *,ENGINE *)
    192 void engine_table_unregister(ENGINE_TABLE **table, ENGINE *e)
    193 	{
    194 	CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
    195 	if(int_table_check(table, 0))
    196 		lh_doall_arg(&(*table)->piles,
    197 			LHASH_DOALL_ARG_FN(int_unregister_cb), e);
    198 	CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
    199 	}
    200 
    201 static void int_cleanup_cb(ENGINE_PILE *p)
    202 	{
    203 	sk_ENGINE_free(p->sk);
    204 	if(p->funct)
    205 		engine_unlocked_finish(p->funct, 0);
    206 	OPENSSL_free(p);
    207 	}
    208 static IMPLEMENT_LHASH_DOALL_FN(int_cleanup_cb,ENGINE_PILE *)
    209 void engine_table_cleanup(ENGINE_TABLE **table)
    210 	{
    211 	CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
    212 	if(*table)
    213 		{
    214 		lh_doall(&(*table)->piles, LHASH_DOALL_FN(int_cleanup_cb));
    215 		lh_free(&(*table)->piles);
    216 		*table = NULL;
    217 		}
    218 	CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
    219 	}
    220 
    221 /* return a functional reference for a given 'nid' */
    222 #ifndef ENGINE_TABLE_DEBUG
    223 ENGINE *engine_table_select(ENGINE_TABLE **table, int nid)
    224 #else
    225 ENGINE *engine_table_select_tmp(ENGINE_TABLE **table, int nid, const char *f, int l)
    226 #endif
    227 	{
    228 	ENGINE *ret = NULL;
    229 	ENGINE_PILE tmplate, *fnd=NULL;
    230 	int initres, loop = 0;
    231 
    232 	if(!(*table))
    233 		{
    234 #ifdef ENGINE_TABLE_DEBUG
    235 		fprintf(stderr, "engine_table_dbg: %s:%d, nid=%d, nothing "
    236 			"registered!\n", f, l, nid);
    237 #endif
    238 		return NULL;
    239 		}
    240 	ERR_set_mark();
    241 	CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
    242 	/* Check again inside the lock otherwise we could race against cleanup
    243 	 * operations. But don't worry about a fprintf(stderr). */
    244 	if(!int_table_check(table, 0)) goto end;
    245 	tmplate.nid = nid;
    246 	fnd = lh_retrieve(&(*table)->piles, &tmplate);
    247 	if(!fnd) goto end;
    248 	if(fnd->funct && engine_unlocked_init(fnd->funct))
    249 		{
    250 #ifdef ENGINE_TABLE_DEBUG
    251 		fprintf(stderr, "engine_table_dbg: %s:%d, nid=%d, using "
    252 			"ENGINE '%s' cached\n", f, l, nid, fnd->funct->id);
    253 #endif
    254 		ret = fnd->funct;
    255 		goto end;
    256 		}
    257 	if(fnd->uptodate)
    258 		{
    259 		ret = fnd->funct;
    260 		goto end;
    261 		}
    262 trynext:
    263 	ret = sk_ENGINE_value(fnd->sk, loop++);
    264 	if(!ret)
    265 		{
    266 #ifdef ENGINE_TABLE_DEBUG
    267 		fprintf(stderr, "engine_table_dbg: %s:%d, nid=%d, no "
    268 				"registered implementations would initialise\n",
    269 				f, l, nid);
    270 #endif
    271 		goto end;
    272 		}
    273 	/* Try to initialise the ENGINE? */
    274 	if((ret->funct_ref > 0) || !(table_flags & ENGINE_TABLE_FLAG_NOINIT))
    275 		initres = engine_unlocked_init(ret);
    276 	else
    277 		initres = 0;
    278 	if(initres)
    279 		{
    280 		/* Update 'funct' */
    281 		if((fnd->funct != ret) && engine_unlocked_init(ret))
    282 			{
    283 			/* If there was a previous default we release it. */
    284 			if(fnd->funct)
    285 				engine_unlocked_finish(fnd->funct, 0);
    286 			fnd->funct = ret;
    287 #ifdef ENGINE_TABLE_DEBUG
    288 			fprintf(stderr, "engine_table_dbg: %s:%d, nid=%d, "
    289 				"setting default to '%s'\n", f, l, nid, ret->id);
    290 #endif
    291 			}
    292 #ifdef ENGINE_TABLE_DEBUG
    293 		fprintf(stderr, "engine_table_dbg: %s:%d, nid=%d, using "
    294 				"newly initialised '%s'\n", f, l, nid, ret->id);
    295 #endif
    296 		goto end;
    297 		}
    298 	goto trynext;
    299 end:
    300 	/* If it failed, it is unlikely to succeed again until some future
    301 	 * registrations have taken place. In all cases, we cache. */
    302 	if(fnd) fnd->uptodate = 1;
    303 #ifdef ENGINE_TABLE_DEBUG
    304 	if(ret)
    305 		fprintf(stderr, "engine_table_dbg: %s:%d, nid=%d, caching "
    306 				"ENGINE '%s'\n", f, l, nid, ret->id);
    307 	else
    308 		fprintf(stderr, "engine_table_dbg: %s:%d, nid=%d, caching "
    309 				"'no matching ENGINE'\n", f, l, nid);
    310 #endif
    311 	CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
    312 	/* Whatever happened, any failed init()s are not failures in this
    313 	 * context, so clear our error state. */
    314 	ERR_pop_to_mark();
    315 	return ret;
    316 	}
    317