crypto/engine/eng_table.c

   1 /*
   2  * Copyright 2001-2018 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.h"
  11 #include <openssl/evp.h>
  12 #include <openssl/lhash.h>
  13 #include "eng_int.h"
  14
  15 /* The type of the items in the table */
  16 struct st_engine_pile {
  17     /* The 'nid' of this algorithm/mode */
  18     int nid;
  19     /* ENGINEs that implement this algorithm/mode. */
  20     STACK_OF(ENGINE) *sk;
  21     /* The default ENGINE to perform this algorithm/mode. */
  22     ENGINE *funct;
  23     /*
  24      * Zero if 'sk' is newer than the cached 'funct', non-zero otherwise
  25      */
  26     int uptodate;
  27 };
  28
  29 /* The type exposed in eng_int.h */
  30 struct st_engine_table {
  31     LHASH_OF(ENGINE_PILE) piles;
  32 };                              /* ENGINE_TABLE */
  33
  34 typedef struct st_engine_pile_doall {
  35     engine_table_doall_cb *cb;
  36     void *arg;
  37 } ENGINE_PILE_DOALL;
  38
  39 /* Global flags (ENGINE_TABLE_FLAG_***). */
  40 static unsigned int table_flags = 0;
  41
  42 /* API function manipulating 'table_flags' */
  43 unsigned int ENGINE_get_table_flags(void)
  44 {
  45     return table_flags;
  46 }
  47
  48 void ENGINE_set_table_flags(unsigned int flags)
  49 {
  50     table_flags = flags;
  51 }
  52
  53 /* Internal functions for the "piles" hash table */
  54 static unsigned long engine_pile_hash(const ENGINE_PILE *c)
  55 {
  56     return c->nid;
  57 }
  58
  59 static int engine_pile_cmp(const ENGINE_PILE *a, const ENGINE_PILE *b)
  60 {
  61     return a->nid - b->nid;
  62 }
  63
  64 static int int_table_check(ENGINE_TABLE **t, int create)
  65 {
  66     LHASH_OF(ENGINE_PILE) *lh;
  67
  68     if (*t)
  69         return 1;
  70     if (!create)
  71         return 0;
  72     if ((lh = lh_ENGINE_PILE_new(engine_pile_hash, engine_pile_cmp)) == NULL)
  73         return 0;
  74     *t = (ENGINE_TABLE *)lh;
  75     return 1;
  76 }
  77
  78 /*
  79  * Privately exposed (via eng_int.h) functions for adding and/or removing
  80  * ENGINEs from the implementation table
  81  */
  82 int engine_table_register(ENGINE_TABLE **table, ENGINE_CLEANUP_CB *cleanup,
  83                           ENGINE *e, const int *nids, int num_nids,
  84                           int setdefault)
  85 {
  86     int ret = 0, added = 0;
  87     ENGINE_PILE tmplate, *fnd;
  88     CRYPTO_THREAD_write_lock(global_engine_lock);
  89     if (!(*table))
  90         added = 1;
  91     if (!int_table_check(table, 1))
  92         goto end;
  93     if (added)
  94         /* The cleanup callback needs to be added */
  95         engine_cleanup_add_first(cleanup);
  96     while (num_nids--) {
  97         tmplate.nid = *nids;
  98         fnd = lh_ENGINE_PILE_retrieve(&(*table)->piles, &tmplate);
  99         if (!fnd) {
 100             fnd = OPENSSL_malloc(sizeof(*fnd));
 101             if (fnd == NULL)
 102                 goto end;
 103             fnd->uptodate = 1;
 104             fnd->nid = *nids;
 105             fnd->sk = sk_ENGINE_new_null();
 106             if (!fnd->sk) {
 107                 OPENSSL_free(fnd);
 108                 goto end;
 109             }
 110             fnd->funct = NULL;
 111             (void)lh_ENGINE_PILE_insert(&(*table)->piles, fnd);
 112             if (lh_ENGINE_PILE_retrieve(&(*table)->piles, &tmplate) != fnd) {
 113                 sk_ENGINE_free(fnd->sk);
 114                 OPENSSL_free(fnd);
 115                 goto end;
 116             }
 117         }
 118         /* A registration shouldn't add duplicate entries */
 119         (void)sk_ENGINE_delete_ptr(fnd->sk, e);
 120         /*
 121          * if 'setdefault', this ENGINE goes to the head of the list
 122          */
 123         if (!sk_ENGINE_push(fnd->sk, e))
 124             goto end;
 125         /* "touch" this ENGINE_PILE */
 126         fnd->uptodate = 0;
 127         if (setdefault) {
 128             if (!engine_unlocked_init(e)) {
 129                 ENGINEerr(ENGINE_F_ENGINE_TABLE_REGISTER,
 130                           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)
 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 #ifndef ENGINE_TABLE_DEBUG
 193 ENGINE *engine_table_select(ENGINE_TABLE **table, int nid)
 194 #else
 195 ENGINE *engine_table_select_tmp(ENGINE_TABLE **table, int nid, const char *f,
 196                                 int l)
 197 #endif
 198 {
 199     ENGINE *ret = NULL;
 200     ENGINE_PILE tmplate, *fnd = NULL;
 201     int initres, loop = 0;
 202
 203     if (!(*table)) {
 204 #ifdef ENGINE_TABLE_DEBUG
 205         fprintf(stderr, "engine_table_dbg: %s:%d, nid=%d, nothing "
 206                 "registered!\n", f, l, nid);
 207 #endif
 208         return NULL;
 209     }
 210     ERR_set_mark();
 211     CRYPTO_THREAD_write_lock(global_engine_lock);
 212     /*
 213      * Check again inside the lock otherwise we could race against cleanup
 214      * operations. But don't worry about a fprintf(stderr).
 215      */
 216     if (!int_table_check(table, 0))
 217         goto end;
 218     tmplate.nid = nid;
 219     fnd = lh_ENGINE_PILE_retrieve(&(*table)->piles, &tmplate);
 220     if (!fnd)
 221         goto end;
 222     if (fnd->funct && engine_unlocked_init(fnd->funct)) {
 223 #ifdef ENGINE_TABLE_DEBUG
 224         fprintf(stderr, "engine_table_dbg: %s:%d, nid=%d, using "
 225                 "ENGINE '%s' cached\n", f, l, nid, fnd->funct->id);
 226 #endif
 227         ret = fnd->funct;
 228         goto end;
 229     }
 230     if (fnd->uptodate) {
 231         ret = fnd->funct;
 232         goto end;
 233     }
 234  trynext:
 235     ret = sk_ENGINE_value(fnd->sk, loop++);
 236     if (!ret) {
 237 #ifdef ENGINE_TABLE_DEBUG
 238         fprintf(stderr, "engine_table_dbg: %s:%d, nid=%d, no "
 239                 "registered implementations would initialise\n", f, l, nid);
 240 #endif
 241         goto end;
 242     }
 243     /* Try to initialise the ENGINE? */
 244     if ((ret->funct_ref > 0) || !(table_flags & ENGINE_TABLE_FLAG_NOINIT))
 245         initres = engine_unlocked_init(ret);
 246     else
 247         initres = 0;
 248     if (initres) {
 249         /* Update 'funct' */
 250         if ((fnd->funct != ret) && engine_unlocked_init(ret)) {
 251             /* If there was a previous default we release it. */
 252             if (fnd->funct)
 253                 engine_unlocked_finish(fnd->funct, 0);
 254             fnd->funct = ret;
 255 #ifdef ENGINE_TABLE_DEBUG
 256             fprintf(stderr, "engine_table_dbg: %s:%d, nid=%d, "
 257                     "setting default to '%s'\n", f, l, nid, ret->id);
 258 #endif
 259         }
 260 #ifdef ENGINE_TABLE_DEBUG
 261         fprintf(stderr, "engine_table_dbg: %s:%d, nid=%d, using "
 262                 "newly initialised '%s'\n", f, l, nid, ret->id);
 263 #endif
 264         goto end;
 265     }
 266     goto trynext;
 267  end:
 268     /*
 269      * If it failed, it is unlikely to succeed again until some future
 270      * registrations have taken place. In all cases, we cache.
 271      */
 272     if (fnd)
 273         fnd->uptodate = 1;
 274 #ifdef ENGINE_TABLE_DEBUG
 275     if (ret)
 276         fprintf(stderr, "engine_table_dbg: %s:%d, nid=%d, caching "
 277                 "ENGINE '%s'\n", f, l, nid, ret->id);
 278     else
 279         fprintf(stderr, "engine_table_dbg: %s:%d, nid=%d, caching "
 280                 "'no matching ENGINE'\n", f, l, nid);
 281 #endif
 282     CRYPTO_THREAD_unlock(global_engine_lock);
 283     /*
 284      * Whatever happened, any failed init()s are not failures in this
 285      * context, so clear our error state.
 286      */
 287     ERR_pop_to_mark();
 288     return ret;
 289 }
 290
 291 /* Table enumeration */
 292
 293 static void int_dall(const ENGINE_PILE *pile, ENGINE_PILE_DOALL *dall)
 294 {
 295     dall->cb(pile->nid, pile->sk, pile->funct, dall->arg);
 296 }
 297
 298 IMPLEMENT_LHASH_DOALL_ARG_CONST(ENGINE_PILE, ENGINE_PILE_DOALL);
 299
 300 void engine_table_doall(ENGINE_TABLE *table, engine_table_doall_cb *cb,
 301                         void *arg)
 302 {
 303     ENGINE_PILE_DOALL dall;
 304     dall.cb = cb;
 305     dall.arg = arg;
 306     if (table)
 307         lh_ENGINE_PILE_doall_ENGINE_PILE_DOALL(&table->piles, int_dall, &dall);
 308 }