crypto/engine/eng_table.c

   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@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@cryptsoft.com).  This product includes software written by Tim
  51  * Hudson (tjh@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     /* The 'nid' of this algorithm/mode */
  63     int nid;
  64     /* ENGINEs that implement this algorithm/mode. */
  65     STACK_OF(ENGINE) *sk;
  66     /* The default ENGINE to perform this algorithm/mode. */
  67     ENGINE *funct;
  68     /*
  69      * Zero if 'sk' is newer than the cached 'funct', non-zero otherwise
  70      */
  71     int uptodate;
  72 } ENGINE_PILE;
  73
  74 /* The type exposed in eng_int.h */
  75 struct st_engine_table {
  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
  88 void ENGINE_set_table_flags(unsigned int flags)
  89 {
  90     table_flags = flags;
  91 }
  92
  93 /* Internal functions for the "piles" hash table */
  94 static unsigned long engine_pile_hash(const ENGINE_PILE *c)
  95 {
  96     return c->nid;
  97 }
  98
  99 static int engine_pile_cmp(const ENGINE_PILE *a, const ENGINE_PILE *b)
 100 {
 101     return a->nid - b->nid;
 102 }
 103
 104 static IMPLEMENT_LHASH_HASH_FN(engine_pile_hash, const ENGINE_PILE *)
 105 static IMPLEMENT_LHASH_COMP_FN(engine_pile_cmp, const ENGINE_PILE *)
 106 static int int_table_check(ENGINE_TABLE **t, int create)
 107 {
 108     LHASH *lh;
 109     if (*t)
 110         return 1;
 111     if (!create)
 112         return 0;
 113     if ((lh = lh_new(LHASH_HASH_FN(engine_pile_hash),
 114                      LHASH_COMP_FN(engine_pile_cmp))) == NULL)
 115         return 0;
 116     *t = (ENGINE_TABLE *)lh;
 117     return 1;
 118 }
 119
 120 /*
 121  * Privately exposed (via eng_int.h) functions for adding and/or removing
 122  * ENGINEs from the implementation table
 123  */
 124 int engine_table_register(ENGINE_TABLE **table, ENGINE_CLEANUP_CB *cleanup,
 125                           ENGINE *e, const int *nids, int num_nids,
 126                           int setdefault)
 127 {
 128     int ret = 0, added = 0;
 129     ENGINE_PILE tmplate, *fnd;
 130     CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
 131     if (!(*table))
 132         added = 1;
 133     if (!int_table_check(table, 1))
 134         goto end;
 135     if (added)
 136         /* The cleanup callback needs to be added */
 137         engine_cleanup_add_first(cleanup);
 138     while (num_nids--) {
 139         tmplate.nid = *nids;
 140         fnd = lh_retrieve(&(*table)->piles, &tmplate);
 141         if (!fnd) {
 142             fnd = OPENSSL_malloc(sizeof(ENGINE_PILE));
 143             if (!fnd)
 144                 goto end;
 145             fnd->uptodate = 1;
 146             fnd->nid = *nids;
 147             fnd->sk = sk_ENGINE_new_null();
 148             if (!fnd->sk) {
 149                 OPENSSL_free(fnd);
 150                 goto end;
 151             }
 152             fnd->funct = NULL;
 153             lh_insert(&(*table)->piles, fnd);
 154         }
 155         /* A registration shouldn't add duplciate entries */
 156         (void)sk_ENGINE_delete_ptr(fnd->sk, e);
 157         /*
 158          * if 'setdefault', this ENGINE goes to the head of the list
 159          */
 160         if (!sk_ENGINE_push(fnd->sk, e))
 161             goto end;
 162         /* "touch" this ENGINE_PILE */
 163         fnd->uptodate = 0;
 164         if (setdefault) {
 165             if (!engine_unlocked_init(e)) {
 166                 ENGINEerr(ENGINE_F_ENGINE_TABLE_REGISTER,
 167                           ENGINE_R_INIT_FAILED);
 168                 goto end;
 169             }
 170             if (fnd->funct)
 171                 engine_unlocked_finish(fnd->funct, 0);
 172             fnd->funct = e;
 173             fnd->uptodate = 1;
 174         }
 175         nids++;
 176     }
 177     ret = 1;
 178  end:
 179     CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
 180     return ret;
 181 }
 182
 183 static void int_unregister_cb(ENGINE_PILE *pile, ENGINE *e)
 184 {
 185     int n;
 186     /* Iterate the 'c->sk' stack removing any occurance of 'e' */
 187     while ((n = sk_ENGINE_find(pile->sk, e)) >= 0) {
 188         (void)sk_ENGINE_delete(pile->sk, n);
 189         pile->uptodate = 0;
 190     }
 191     if (pile->funct == e) {
 192         engine_unlocked_finish(e, 0);
 193         pile->funct = NULL;
 194     }
 195 }
 196
 197 static IMPLEMENT_LHASH_DOALL_ARG_FN(int_unregister_cb, ENGINE_PILE *,
 198                                     ENGINE *)
 199 void engine_table_unregister(ENGINE_TABLE **table, ENGINE *e)
 200 {
 201     CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
 202     if (int_table_check(table, 0))
 203         lh_doall_arg(&(*table)->piles,
 204                      LHASH_DOALL_ARG_FN(int_unregister_cb), e);
 205     CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
 206 }
 207
 208 static void int_cleanup_cb(ENGINE_PILE *p)
 209 {
 210     sk_ENGINE_free(p->sk);
 211     if (p->funct)
 212         engine_unlocked_finish(p->funct, 0);
 213     OPENSSL_free(p);
 214 }
 215
 216 static IMPLEMENT_LHASH_DOALL_FN(int_cleanup_cb, ENGINE_PILE *)
 217 void engine_table_cleanup(ENGINE_TABLE **table)
 218 {
 219     CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
 220     if (*table) {
 221         lh_doall(&(*table)->piles, LHASH_DOALL_FN(int_cleanup_cb));
 222         lh_free(&(*table)->piles);
 223         *table = NULL;
 224     }
 225     CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
 226 }
 227
 228 /* return a functional reference for a given 'nid' */
 229 #ifndef ENGINE_TABLE_DEBUG
 230 ENGINE *engine_table_select(ENGINE_TABLE **table, int nid)
 231 #else
 232 ENGINE *engine_table_select_tmp(ENGINE_TABLE **table, int nid, const char *f,
 233                                 int l)
 234 #endif
 235 {
 236     ENGINE *ret = NULL;
 237     ENGINE_PILE tmplate, *fnd = NULL;
 238     int initres, loop = 0;
 239
 240     if (!(*table)) {
 241 #ifdef ENGINE_TABLE_DEBUG
 242         fprintf(stderr, "engine_table_dbg: %s:%d, nid=%d, nothing "
 243                 "registered!\n", f, l, nid);
 244 #endif
 245         return NULL;
 246     }
 247     ERR_set_mark();
 248     CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
 249     /*
 250      * Check again inside the lock otherwise we could race against cleanup
 251      * operations. But don't worry about a fprintf(stderr).
 252      */
 253     if (!int_table_check(table, 0))
 254         goto end;
 255     tmplate.nid = nid;
 256     fnd = lh_retrieve(&(*table)->piles, &tmplate);
 257     if (!fnd)
 258         goto end;
 259     if (fnd->funct && engine_unlocked_init(fnd->funct)) {
 260 #ifdef ENGINE_TABLE_DEBUG
 261         fprintf(stderr, "engine_table_dbg: %s:%d, nid=%d, using "
 262                 "ENGINE '%s' cached\n", f, l, nid, fnd->funct->id);
 263 #endif
 264         ret = fnd->funct;
 265         goto end;
 266     }
 267     if (fnd->uptodate) {
 268         ret = fnd->funct;
 269         goto end;
 270     }
 271  trynext:
 272     ret = sk_ENGINE_value(fnd->sk, loop++);
 273     if (!ret) {
 274 #ifdef ENGINE_TABLE_DEBUG
 275         fprintf(stderr, "engine_table_dbg: %s:%d, nid=%d, no "
 276                 "registered implementations would initialise\n", f, l, nid);
 277 #endif
 278         goto end;
 279     }
 280     /* Try to initialise the ENGINE? */
 281     if ((ret->funct_ref > 0) || !(table_flags & ENGINE_TABLE_FLAG_NOINIT))
 282         initres = engine_unlocked_init(ret);
 283     else
 284         initres = 0;
 285     if (initres) {
 286         /* Update 'funct' */
 287         if ((fnd->funct != ret) && engine_unlocked_init(ret)) {
 288             /* If there was a previous default we release it. */
 289             if (fnd->funct)
 290                 engine_unlocked_finish(fnd->funct, 0);
 291             fnd->funct = ret;
 292 #ifdef ENGINE_TABLE_DEBUG
 293             fprintf(stderr, "engine_table_dbg: %s:%d, nid=%d, "
 294                     "setting default to '%s'\n", f, l, nid, ret->id);
 295 #endif
 296         }
 297 #ifdef ENGINE_TABLE_DEBUG
 298         fprintf(stderr, "engine_table_dbg: %s:%d, nid=%d, using "
 299                 "newly initialised '%s'\n", f, l, nid, ret->id);
 300 #endif
 301         goto end;
 302     }
 303     goto trynext;
 304  end:
 305     /*
 306      * If it failed, it is unlikely to succeed again until some future
 307      * registrations have taken place. In all cases, we cache.
 308      */
 309     if (fnd)
 310         fnd->uptodate = 1;
 311 #ifdef ENGINE_TABLE_DEBUG
 312     if (ret)
 313         fprintf(stderr, "engine_table_dbg: %s:%d, nid=%d, caching "
 314                 "ENGINE '%s'\n", f, l, nid, ret->id);
 315     else
 316         fprintf(stderr, "engine_table_dbg: %s:%d, nid=%d, caching "
 317                 "'no matching ENGINE'\n", f, l, nid);
 318 #endif
 319     CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
 320     /*
 321      * Whatever happened, any failed init()s are not failures in this
 322      * context, so clear our error state.
 323      */
 324     ERR_pop_to_mark();
 325     return ret;
 326 }