crypto/engine/eng_table.c

   1 /*
   2  * Copyright 2001-2020 The OpenSSL Project Authors. All Rights Reserved.
   3  *
   4  * Licensed under the Apache License 2.0 (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.h"
  11 #include <openssl/evp.h>
  12 #include <openssl/lhash.h>
  13 #include <openssl/trace.h>
  14 #include "eng_local.h"
  15
  16 /* The type of the items in the table */
  17 struct st_engine_pile {
  18     /* The 'nid' of this algorithm/mode */
  19     int nid;
  20     /* ENGINEs that implement this algorithm/mode. */
  21     STACK_OF(ENGINE) *sk;
  22     /* The default ENGINE to perform this algorithm/mode. */
  23     ENGINE *funct;
  24     /*
  25      * Zero if 'sk' is newer than the cached 'funct', non-zero otherwise
  26      */
  27     int uptodate;
  28 };
  29
  30 /* The type exposed in eng_local.h */
  31 struct st_engine_table {
  32     LHASH_OF(ENGINE_PILE) piles;
  33 };                              /* ENGINE_TABLE */
  34
  35 typedef struct st_engine_pile_doall {
  36     engine_table_doall_cb *cb;
  37     void *arg;
  38 } ENGINE_PILE_DOALL;
  39
  40 /* Global flags (ENGINE_TABLE_FLAG_***). */
  41 static unsigned int table_flags = 0;
  42
  43 /* API function manipulating 'table_flags' */
  44 unsigned int ENGINE_get_table_flags(void)
  45 {
  46     return table_flags;
  47 }
  48
  49 void ENGINE_set_table_flags(unsigned int flags)
  50 {
  51     table_flags = flags;
  52 }
  53
  54 /* Internal functions for the "piles" hash table */
  55 static unsigned long engine_pile_hash(const ENGINE_PILE *c)
  56 {
  57     return c->nid;
  58 }
  59
  60 static int engine_pile_cmp(const ENGINE_PILE *a, const ENGINE_PILE *b)
  61 {
  62     return a->nid - b->nid;
  63 }
  64
  65 static int int_table_check(ENGINE_TABLE **t, int create)
  66 {
  67     LHASH_OF(ENGINE_PILE) *lh;
  68
  69     if (*t)
  70         return 1;
  71     if (!create)
  72         return 0;
  73     if ((lh = lh_ENGINE_PILE_new(engine_pile_hash, engine_pile_cmp)) == NULL)
  74         return 0;
  75     *t = (ENGINE_TABLE *)lh;
  76     return 1;
  77 }
  78
  79 /*
  80  * Privately exposed (via eng_local.h) functions for adding and/or removing
  81  * ENGINEs from the implementation table
  82  */
  83 int engine_table_register(ENGINE_TABLE **table, ENGINE_CLEANUP_CB *cleanup,
  84                           ENGINE *e, const int *nids, int num_nids,
  85                           int setdefault)
  86 {
  87     int ret = 0, added = 0;
  88     ENGINE_PILE tmplate, *fnd;
  89     CRYPTO_THREAD_write_lock(global_engine_lock);
  90     if (!(*table))
  91         added = 1;
  92     if (!int_table_check(table, 1))
  93         goto end;
  94     if (added)
  95         /* The cleanup callback needs to be added */
  96         engine_cleanup_add_first(cleanup);
  97     while (num_nids--) {
  98         tmplate.nid = *nids;
  99         fnd = lh_ENGINE_PILE_retrieve(&(*table)->piles, &tmplate);
 100         if (!fnd) {
 101             fnd = OPENSSL_malloc(sizeof(*fnd));
 102             if (fnd == NULL)
 103                 goto end;
 104             fnd->uptodate = 1;
 105             fnd->nid = *nids;
 106             fnd->sk = sk_ENGINE_new_null();
 107             if (!fnd->sk) {
 108                 OPENSSL_free(fnd);
 109                 goto end;
 110             }
 111             fnd->funct = NULL;
 112             (void)lh_ENGINE_PILE_insert(&(*table)->piles, fnd);
 113             if (lh_ENGINE_PILE_retrieve(&(*table)->piles, &tmplate) != fnd) {
 114                 sk_ENGINE_free(fnd->sk);
 115                 OPENSSL_free(fnd);
 116                 goto end;
 117             }
 118         }
 119         /* A registration shouldn't add duplicate entries */
 120         (void)sk_ENGINE_delete_ptr(fnd->sk, e);
 121         /*
 122          * if 'setdefault', this ENGINE goes to the head of the list
 123          */
 124         if (!sk_ENGINE_push(fnd->sk, e))
 125             goto end;
 126         /* "touch" this ENGINE_PILE */
 127         fnd->uptodate = 0;
 128         if (setdefault) {
 129             if (!engine_unlocked_init(e)) {
 130                 ERR_raise(ERR_LIB_ENGINE, ENGINE_R_INIT_FAILED);
 131                 goto end;
 132             }
 133             if (fnd->funct)
 134                 engine_unlocked_finish(fnd->funct, 0);
 135             fnd->funct = e;
 136             fnd->uptodate = 1;
 137         }
 138         nids++;
 139     }
 140     ret = 1;
 141  end:
 142     CRYPTO_THREAD_unlock(global_engine_lock);
 143     return ret;
 144 }
 145
 146 static void int_unregister_cb(ENGINE_PILE *pile, ENGINE *e)
 147 {
 148     int n;
 149     /* Iterate the 'c->sk' stack removing any occurrence of 'e' */
 150     while ((n = sk_ENGINE_find(pile->sk, e)) >= 0) {
 151         (void)sk_ENGINE_delete(pile->sk, n);
 152         pile->uptodate = 0;
 153     }
 154     if (pile->funct == e) {
 155         engine_unlocked_finish(e, 0);
 156         pile->funct = NULL;
 157     }
 158 }
 159
 160 IMPLEMENT_LHASH_DOALL_ARG(ENGINE_PILE, ENGINE);
 161
 162 void engine_table_unregister(ENGINE_TABLE **table, ENGINE *e)
 163 {
 164     CRYPTO_THREAD_write_lock(global_engine_lock);
 165     if (int_table_check(table, 0))
 166         lh_ENGINE_PILE_doall_ENGINE(&(*table)->piles, int_unregister_cb, e);
 167     CRYPTO_THREAD_unlock(global_engine_lock);
 168 }
 169
 170 static void int_cleanup_cb_doall(ENGINE_PILE *p)
 171 {
 172     if (p == NULL)
 173         return;
 174     sk_ENGINE_free(p->sk);
 175     if (p->funct)
 176         engine_unlocked_finish(p->funct, 0);
 177     OPENSSL_free(p);
 178 }
 179
 180 void engine_table_cleanup(ENGINE_TABLE **table)
 181 {
 182     CRYPTO_THREAD_write_lock(global_engine_lock);
 183     if (*table) {
 184         lh_ENGINE_PILE_doall(&(*table)->piles, int_cleanup_cb_doall);
 185         lh_ENGINE_PILE_free(&(*table)->piles);
 186         *table = NULL;
 187     }
 188     CRYPTO_THREAD_unlock(global_engine_lock);
 189 }
 190
 191 /* return a functional reference for a given 'nid' */
 192 ENGINE *engine_table_select_int(ENGINE_TABLE **table, int nid, const char *f,
 193                                 int l)
 194 {
 195     ENGINE *ret = NULL;
 196     ENGINE_PILE tmplate, *fnd = NULL;
 197     int initres, loop = 0;
 198
 199     /* Load the config before trying to check if engines are available */
 200     OPENSSL_init_crypto(OPENSSL_INIT_LOAD_CONFIG, NULL);
 201
 202     if (!(*table)) {
 203         OSSL_TRACE3(ENGINE_TABLE,
 204                    "%s:%d, nid=%d, nothing registered!\n",
 205                    f, l, nid);
 206         return NULL;
 207     }
 208     ERR_set_mark();
 209     CRYPTO_THREAD_write_lock(global_engine_lock);
 210     /*
 211      * Check again inside the lock otherwise we could race against cleanup
 212      * operations. But don't worry about a debug printout
 213      */
 214     if (!int_table_check(table, 0))
 215         goto end;
 216     tmplate.nid = nid;
 217     fnd = lh_ENGINE_PILE_retrieve(&(*table)->piles, &tmplate);
 218     if (!fnd)
 219         goto end;
 220     if (fnd->funct && engine_unlocked_init(fnd->funct)) {
 221         OSSL_TRACE4(ENGINE_TABLE,
 222                    "%s:%d, nid=%d, using ENGINE '%s' cached\n",
 223                    f, l, nid, fnd->funct->id);
 224         ret = fnd->funct;
 225         goto end;
 226     }
 227     if (fnd->uptodate) {
 228         ret = fnd->funct;
 229         goto end;
 230     }
 231  trynext:
 232     ret = sk_ENGINE_value(fnd->sk, loop++);
 233     if (!ret) {
 234         OSSL_TRACE3(ENGINE_TABLE,
 235                     "%s:%d, nid=%d, "
 236                     "no registered implementations would initialise\n",
 237                     f, l, nid);
 238         goto end;
 239     }
 240     /* Try to initialise the ENGINE? */
 241     if ((ret->funct_ref > 0) || !(table_flags & ENGINE_TABLE_FLAG_NOINIT))
 242         initres = engine_unlocked_init(ret);
 243     else
 244         initres = 0;
 245     if (initres) {
 246         /* Update 'funct' */
 247         if ((fnd->funct != ret) && engine_unlocked_init(ret)) {
 248             /* If there was a previous default we release it. */
 249             if (fnd->funct)
 250                 engine_unlocked_finish(fnd->funct, 0);
 251             fnd->funct = ret;
 252             OSSL_TRACE4(ENGINE_TABLE,
 253                         "%s:%d, nid=%d, setting default to '%s'\n",
 254                         f, l, nid, ret->id);
 255         }
 256         OSSL_TRACE4(ENGINE_TABLE,
 257                     "%s:%d, nid=%d, using newly initialised '%s'\n",
 258                     f, l, nid, ret->id);
 259         goto end;
 260     }
 261     goto trynext;
 262  end:
 263     /*
 264      * If it failed, it is unlikely to succeed again until some future
 265      * registrations have taken place. In all cases, we cache.
 266      */
 267     if (fnd)
 268         fnd->uptodate = 1;
 269     if (ret)
 270         OSSL_TRACE4(ENGINE_TABLE,
 271                    "%s:%d, nid=%d, caching ENGINE '%s'\n",
 272                    f, l, nid, ret->id);
 273     else
 274         OSSL_TRACE3(ENGINE_TABLE,
 275                     "%s:%d, nid=%d, caching 'no matching ENGINE'\n",
 276                     f, l, nid);
 277     CRYPTO_THREAD_unlock(global_engine_lock);
 278     /*
 279      * Whatever happened, any failed init()s are not failures in this
 280      * context, so clear our error state.
 281      */
 282     ERR_pop_to_mark();
 283     return ret;
 284 }
 285
 286 /* Table enumeration */
 287
 288 static void int_dall(const ENGINE_PILE *pile, ENGINE_PILE_DOALL *dall)
 289 {
 290     dall->cb(pile->nid, pile->sk, pile->funct, dall->arg);
 291 }
 292
 293 IMPLEMENT_LHASH_DOALL_ARG_CONST(ENGINE_PILE, ENGINE_PILE_DOALL);
 294
 295 void engine_table_doall(ENGINE_TABLE *table, engine_table_doall_cb *cb,
 296                         void *arg)
 297 {
 298     ENGINE_PILE_DOALL dall;
 299     dall.cb = cb;
 300     dall.arg = arg;
 301     if (table)
 302         lh_ENGINE_PILE_doall_ENGINE_PILE_DOALL(&table->piles, int_dall, &dall);
 303 }