eng_table.c revision 296465 
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 */
61typedef 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 */
75struct st_engine_table {
76    LHASH piles;
77};                              /* ENGINE_TABLE */
78
79/* Global flags (ENGINE_TABLE_FLAG_***). */
80static unsigned int table_flags = 0;
81
82/* API function manipulating 'table_flags' */
83unsigned int ENGINE_get_table_flags(void)
84{
85    return table_flags;
86}
87
88void ENGINE_set_table_flags(unsigned int flags)
89{
90    table_flags = flags;
91}
92
93/* Internal functions for the "piles" hash table */
94static unsigned long engine_pile_hash(const ENGINE_PILE *c)
95{
96    return c->nid;
97}
98
99static int engine_pile_cmp(const ENGINE_PILE *a, const ENGINE_PILE *b)
100{
101    return a->nid - b->nid;
102}
103
104static IMPLEMENT_LHASH_HASH_FN(engine_pile_hash, const ENGINE_PILE *)
105static IMPLEMENT_LHASH_COMP_FN(engine_pile_cmp, const ENGINE_PILE *)
106static 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 */
124int 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
183static 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
197static IMPLEMENT_LHASH_DOALL_ARG_FN(int_unregister_cb, ENGINE_PILE *,
198                                    ENGINE *)
199void 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
208static 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
216static IMPLEMENT_LHASH_DOALL_FN(int_cleanup_cb, ENGINE_PILE *)
217void 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
230ENGINE *engine_table_select(ENGINE_TABLE **table, int nid)
231#else
232ENGINE *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}
327