eng_list.c revision 296465 
1/* crypto/engine/eng_list.c */
2/*
3 * Written by Geoff Thorpe (geoff@geoffthorpe.net) for the OpenSSL project
4 * 2000.
5 */
6/* ====================================================================
7 * Copyright (c) 1999-2001 The OpenSSL Project.  All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 *
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 *
16 * 2. Redistributions in binary form must reproduce the above copyright
17 *    notice, this list of conditions and the following disclaimer in
18 *    the documentation and/or other materials provided with the
19 *    distribution.
20 *
21 * 3. All advertising materials mentioning features or use of this
22 *    software must display the following acknowledgment:
23 *    "This product includes software developed by the OpenSSL Project
24 *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
25 *
26 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
27 *    endorse or promote products derived from this software without
28 *    prior written permission. For written permission, please contact
29 *    licensing@OpenSSL.org.
30 *
31 * 5. Products derived from this software may not be called "OpenSSL"
32 *    nor may "OpenSSL" appear in their names without prior written
33 *    permission of the OpenSSL Project.
34 *
35 * 6. Redistributions of any form whatsoever must retain the following
36 *    acknowledgment:
37 *    "This product includes software developed by the OpenSSL Project
38 *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
39 *
40 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
41 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
42 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
43 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
44 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
45 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
46 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
47 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
49 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
50 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
51 * OF THE POSSIBILITY OF SUCH DAMAGE.
52 * ====================================================================
53 *
54 * This product includes cryptographic software written by Eric Young
55 * (eay@cryptsoft.com).  This product includes software written by Tim
56 * Hudson (tjh@cryptsoft.com).
57 *
58 */
59/* ====================================================================
60 * Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED.
61 * ECDH support in OpenSSL originally developed by
62 * SUN MICROSYSTEMS, INC., and contributed to the OpenSSL project.
63 */
64
65#include "eng_int.h"
66
67/*
68 * The linked-list of pointers to engine types. engine_list_head incorporates
69 * an implicit structural reference but engine_list_tail does not - the
70 * latter is a computational niceity and only points to something that is
71 * already pointed to by its predecessor in the list (or engine_list_head
72 * itself). In the same way, the use of the "prev" pointer in each ENGINE is
73 * to save excessive list iteration, it doesn't correspond to an extra
74 * structural reference. Hence, engine_list_head, and each non-null "next"
75 * pointer account for the list itself assuming exactly 1 structural
76 * reference on each list member.
77 */
78static ENGINE *engine_list_head = NULL;
79static ENGINE *engine_list_tail = NULL;
80
81/*
82 * This cleanup function is only needed internally. If it should be called,
83 * we register it with the "ENGINE_cleanup()" stack to be called during
84 * cleanup.
85 */
86
87static void engine_list_cleanup(void)
88{
89    ENGINE *iterator = engine_list_head;
90
91    while (iterator != NULL) {
92        ENGINE_remove(iterator);
93        iterator = engine_list_head;
94    }
95    return;
96}
97
98/*
99 * These static functions starting with a lower case "engine_" always take
100 * place when CRYPTO_LOCK_ENGINE has been locked up.
101 */
102static int engine_list_add(ENGINE *e)
103{
104    int conflict = 0;
105    ENGINE *iterator = NULL;
106
107    if (e == NULL) {
108        ENGINEerr(ENGINE_F_ENGINE_LIST_ADD, ERR_R_PASSED_NULL_PARAMETER);
109        return 0;
110    }
111    iterator = engine_list_head;
112    while (iterator && !conflict) {
113        conflict = (strcmp(iterator->id, e->id) == 0);
114        iterator = iterator->next;
115    }
116    if (conflict) {
117        ENGINEerr(ENGINE_F_ENGINE_LIST_ADD, ENGINE_R_CONFLICTING_ENGINE_ID);
118        return 0;
119    }
120    if (engine_list_head == NULL) {
121        /* We are adding to an empty list. */
122        if (engine_list_tail) {
123            ENGINEerr(ENGINE_F_ENGINE_LIST_ADD, ENGINE_R_INTERNAL_LIST_ERROR);
124            return 0;
125        }
126        engine_list_head = e;
127        e->prev = NULL;
128        /*
129         * The first time the list allocates, we should register the cleanup.
130         */
131        engine_cleanup_add_last(engine_list_cleanup);
132    } else {
133        /* We are adding to the tail of an existing list. */
134        if ((engine_list_tail == NULL) || (engine_list_tail->next != NULL)) {
135            ENGINEerr(ENGINE_F_ENGINE_LIST_ADD, ENGINE_R_INTERNAL_LIST_ERROR);
136            return 0;
137        }
138        engine_list_tail->next = e;
139        e->prev = engine_list_tail;
140    }
141    /*
142     * Having the engine in the list assumes a structural reference.
143     */
144    e->struct_ref++;
145    engine_ref_debug(e, 0, 1)
146        /* However it came to be, e is the last item in the list. */
147        engine_list_tail = e;
148    e->next = NULL;
149    return 1;
150}
151
152static int engine_list_remove(ENGINE *e)
153{
154    ENGINE *iterator;
155
156    if (e == NULL) {
157        ENGINEerr(ENGINE_F_ENGINE_LIST_REMOVE, ERR_R_PASSED_NULL_PARAMETER);
158        return 0;
159    }
160    /* We need to check that e is in our linked list! */
161    iterator = engine_list_head;
162    while (iterator && (iterator != e))
163        iterator = iterator->next;
164    if (iterator == NULL) {
165        ENGINEerr(ENGINE_F_ENGINE_LIST_REMOVE,
166                  ENGINE_R_ENGINE_IS_NOT_IN_LIST);
167        return 0;
168    }
169    /* un-link e from the chain. */
170    if (e->next)
171        e->next->prev = e->prev;
172    if (e->prev)
173        e->prev->next = e->next;
174    /* Correct our head/tail if necessary. */
175    if (engine_list_head == e)
176        engine_list_head = e->next;
177    if (engine_list_tail == e)
178        engine_list_tail = e->prev;
179    engine_free_util(e, 0);
180    return 1;
181}
182
183/* Get the first/last "ENGINE" type available. */
184ENGINE *ENGINE_get_first(void)
185{
186    ENGINE *ret;
187
188    CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
189    ret = engine_list_head;
190    if (ret) {
191        ret->struct_ref++;
192        engine_ref_debug(ret, 0, 1)
193    }
194    CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
195    return ret;
196}
197
198ENGINE *ENGINE_get_last(void)
199{
200    ENGINE *ret;
201
202    CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
203    ret = engine_list_tail;
204    if (ret) {
205        ret->struct_ref++;
206        engine_ref_debug(ret, 0, 1)
207    }
208    CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
209    return ret;
210}
211
212/* Iterate to the next/previous "ENGINE" type (NULL = end of the list). */
213ENGINE *ENGINE_get_next(ENGINE *e)
214{
215    ENGINE *ret = NULL;
216    if (e == NULL) {
217        ENGINEerr(ENGINE_F_ENGINE_GET_NEXT, ERR_R_PASSED_NULL_PARAMETER);
218        return 0;
219    }
220    CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
221    ret = e->next;
222    if (ret) {
223        /* Return a valid structural refernce to the next ENGINE */
224        ret->struct_ref++;
225        engine_ref_debug(ret, 0, 1)
226    }
227    CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
228    /* Release the structural reference to the previous ENGINE */
229    ENGINE_free(e);
230    return ret;
231}
232
233ENGINE *ENGINE_get_prev(ENGINE *e)
234{
235    ENGINE *ret = NULL;
236    if (e == NULL) {
237        ENGINEerr(ENGINE_F_ENGINE_GET_PREV, ERR_R_PASSED_NULL_PARAMETER);
238        return 0;
239    }
240    CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
241    ret = e->prev;
242    if (ret) {
243        /* Return a valid structural reference to the next ENGINE */
244        ret->struct_ref++;
245        engine_ref_debug(ret, 0, 1)
246    }
247    CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
248    /* Release the structural reference to the previous ENGINE */
249    ENGINE_free(e);
250    return ret;
251}
252
253/* Add another "ENGINE" type into the list. */
254int ENGINE_add(ENGINE *e)
255{
256    int to_return = 1;
257    if (e == NULL) {
258        ENGINEerr(ENGINE_F_ENGINE_ADD, ERR_R_PASSED_NULL_PARAMETER);
259        return 0;
260    }
261    if ((e->id == NULL) || (e->name == NULL)) {
262        ENGINEerr(ENGINE_F_ENGINE_ADD, ENGINE_R_ID_OR_NAME_MISSING);
263    }
264    CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
265    if (!engine_list_add(e)) {
266        ENGINEerr(ENGINE_F_ENGINE_ADD, ENGINE_R_INTERNAL_LIST_ERROR);
267        to_return = 0;
268    }
269    CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
270    return to_return;
271}
272
273/* Remove an existing "ENGINE" type from the array. */
274int ENGINE_remove(ENGINE *e)
275{
276    int to_return = 1;
277    if (e == NULL) {
278        ENGINEerr(ENGINE_F_ENGINE_REMOVE, ERR_R_PASSED_NULL_PARAMETER);
279        return 0;
280    }
281    CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
282    if (!engine_list_remove(e)) {
283        ENGINEerr(ENGINE_F_ENGINE_REMOVE, ENGINE_R_INTERNAL_LIST_ERROR);
284        to_return = 0;
285    }
286    CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
287    return to_return;
288}
289
290static void engine_cpy(ENGINE *dest, const ENGINE *src)
291{
292    dest->id = src->id;
293    dest->name = src->name;
294#ifndef OPENSSL_NO_RSA
295    dest->rsa_meth = src->rsa_meth;
296#endif
297#ifndef OPENSSL_NO_DSA
298    dest->dsa_meth = src->dsa_meth;
299#endif
300#ifndef OPENSSL_NO_DH
301    dest->dh_meth = src->dh_meth;
302#endif
303#ifndef OPENSSL_NO_ECDH
304    dest->ecdh_meth = src->ecdh_meth;
305#endif
306#ifndef OPENSSL_NO_ECDSA
307    dest->ecdsa_meth = src->ecdsa_meth;
308#endif
309    dest->rand_meth = src->rand_meth;
310    dest->store_meth = src->store_meth;
311    dest->ciphers = src->ciphers;
312    dest->digests = src->digests;
313    dest->destroy = src->destroy;
314    dest->init = src->init;
315    dest->finish = src->finish;
316    dest->ctrl = src->ctrl;
317    dest->load_privkey = src->load_privkey;
318    dest->load_pubkey = src->load_pubkey;
319    dest->cmd_defns = src->cmd_defns;
320    dest->flags = src->flags;
321}
322
323ENGINE *ENGINE_by_id(const char *id)
324{
325    ENGINE *iterator;
326    char *load_dir = NULL;
327    if (id == NULL) {
328        ENGINEerr(ENGINE_F_ENGINE_BY_ID, ERR_R_PASSED_NULL_PARAMETER);
329        return NULL;
330    }
331    CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
332    iterator = engine_list_head;
333    while (iterator && (strcmp(id, iterator->id) != 0))
334        iterator = iterator->next;
335    if (iterator) {
336        /*
337         * We need to return a structural reference. If this is an ENGINE
338         * type that returns copies, make a duplicate - otherwise increment
339         * the existing ENGINE's reference count.
340         */
341        if (iterator->flags & ENGINE_FLAGS_BY_ID_COPY) {
342            ENGINE *cp = ENGINE_new();
343            if (!cp)
344                iterator = NULL;
345            else {
346                engine_cpy(cp, iterator);
347                iterator = cp;
348            }
349        } else {
350            iterator->struct_ref++;
351            engine_ref_debug(iterator, 0, 1)
352        }
353    }
354    CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
355#if 0
356    if (iterator == NULL) {
357        ENGINEerr(ENGINE_F_ENGINE_BY_ID, ENGINE_R_NO_SUCH_ENGINE);
358        ERR_add_error_data(2, "id=", id);
359    }
360    return iterator;
361#else
362    /* EEK! Experimental code starts */
363    if (iterator)
364        return iterator;
365    /*
366     * Prevent infinite recusrion if we're looking for the dynamic engine.
367     */
368    if (strcmp(id, "dynamic")) {
369# ifdef OPENSSL_SYS_VMS
370        if ((load_dir = getenv("OPENSSL_ENGINES")) == 0)
371            load_dir = "SSLROOT:[ENGINES]";
372# else
373        if ((load_dir = getenv("OPENSSL_ENGINES")) == 0)
374            load_dir = ENGINESDIR;
375# endif
376        iterator = ENGINE_by_id("dynamic");
377        if (!iterator || !ENGINE_ctrl_cmd_string(iterator, "ID", id, 0) ||
378            !ENGINE_ctrl_cmd_string(iterator, "DIR_LOAD", "2", 0) ||
379            !ENGINE_ctrl_cmd_string(iterator, "DIR_ADD",
380                                    load_dir, 0) ||
381            !ENGINE_ctrl_cmd_string(iterator, "LOAD", NULL, 0))
382            goto notfound;
383        return iterator;
384    }
385 notfound:
386    ENGINE_free(iterator);
387    ENGINEerr(ENGINE_F_ENGINE_BY_ID, ENGINE_R_NO_SUCH_ENGINE);
388    ERR_add_error_data(2, "id=", id);
389    return NULL;
390    /* EEK! Experimental code ends */
391#endif
392}
393
394int ENGINE_up_ref(ENGINE *e)
395{
396    if (e == NULL) {
397        ENGINEerr(ENGINE_F_ENGINE_UP_REF, ERR_R_PASSED_NULL_PARAMETER);
398        return 0;
399    }
400    CRYPTO_add(&e->struct_ref, 1, CRYPTO_LOCK_ENGINE);
401    return 1;
402}
403