2 * Copyright 2001-2021 The OpenSSL Project Authors. All Rights Reserved.
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
10 /* We need to use some engine deprecated APIs */
11 #define OPENSSL_SUPPRESS_DEPRECATED
13 #include "eng_local.h"
14 #include "internal/dso.h"
15 #include <openssl/crypto.h>
18 * Shared libraries implementing ENGINEs for use by the "dynamic" ENGINE
19 * loader should implement the hook-up functions with the following
23 /* Our ENGINE handlers */
24 static int dynamic_init(ENGINE *e);
25 static int dynamic_finish(ENGINE *e);
26 static int dynamic_ctrl(ENGINE *e, int cmd, long i, void *p,
28 /* Predeclare our context type */
29 typedef struct st_dynamic_data_ctx dynamic_data_ctx;
30 /* The implementation for the important control command */
31 static int dynamic_load(ENGINE *e, dynamic_data_ctx *ctx);
33 #define DYNAMIC_CMD_SO_PATH ENGINE_CMD_BASE
34 #define DYNAMIC_CMD_NO_VCHECK (ENGINE_CMD_BASE + 1)
35 #define DYNAMIC_CMD_ID (ENGINE_CMD_BASE + 2)
36 #define DYNAMIC_CMD_LIST_ADD (ENGINE_CMD_BASE + 3)
37 #define DYNAMIC_CMD_DIR_LOAD (ENGINE_CMD_BASE + 4)
38 #define DYNAMIC_CMD_DIR_ADD (ENGINE_CMD_BASE + 5)
39 #define DYNAMIC_CMD_LOAD (ENGINE_CMD_BASE + 6)
41 /* The constants used when creating the ENGINE */
42 static const char *engine_dynamic_id = "dynamic";
43 static const char *engine_dynamic_name = "Dynamic engine loading support";
44 static const ENGINE_CMD_DEFN dynamic_cmd_defns[] = {
47 "Specifies the path to the new ENGINE shared library",
48 ENGINE_CMD_FLAG_STRING},
49 {DYNAMIC_CMD_NO_VCHECK,
51 "Specifies to continue even if version checking fails (boolean)",
52 ENGINE_CMD_FLAG_NUMERIC},
55 "Specifies an ENGINE id name for loading",
56 ENGINE_CMD_FLAG_STRING},
57 {DYNAMIC_CMD_LIST_ADD,
59 "Whether to add a loaded ENGINE to the internal list (0=no,1=yes,2=mandatory)",
60 ENGINE_CMD_FLAG_NUMERIC},
61 {DYNAMIC_CMD_DIR_LOAD,
63 "Specifies whether to load from 'DIR_ADD' directories (0=no,1=yes,2=mandatory)",
64 ENGINE_CMD_FLAG_NUMERIC},
67 "Adds a directory from which ENGINEs can be loaded",
68 ENGINE_CMD_FLAG_STRING},
71 "Load up the ENGINE specified by other settings",
72 ENGINE_CMD_FLAG_NO_INPUT},
77 * Loading code stores state inside the ENGINE structure via the "ex_data"
78 * element. We load all our state into a single structure and use that as a
79 * single context in the "ex_data" stack.
81 struct st_dynamic_data_ctx {
82 /* The DSO object we load that supplies the ENGINE code */
85 * The function pointer to the version checking shared library function
87 dynamic_v_check_fn v_check;
89 * The function pointer to the engine-binding shared library function
91 dynamic_bind_engine bind_engine;
92 /* The default name/path for loading the shared library */
93 char *DYNAMIC_LIBNAME;
94 /* Whether to continue loading on a version check failure */
96 /* If non-NULL, stipulates the 'id' of the ENGINE to be loaded */
99 * If non-zero, a successfully loaded ENGINE should be added to the
100 * internal ENGINE list. If 2, the add must succeed or the entire load
104 /* The symbol name for the version checking function */
105 const char *DYNAMIC_F1;
106 /* The symbol name for the "initialise ENGINE structure" function */
107 const char *DYNAMIC_F2;
109 * Whether to never use 'dirs', use 'dirs' as a fallback, or only use
110 * 'dirs' for loading. Default is to use 'dirs' as a fallback.
113 /* A stack of directories from which ENGINEs could be loaded */
114 STACK_OF(OPENSSL_STRING) *dirs;
118 * This is the "ex_data" index we obtain and reserve for use with our context
121 static int dynamic_ex_data_idx = -1;
123 static void int_free_str(char *s)
129 * Because our ex_data element may or may not get allocated depending on
130 * whether a "first-use" occurs before the ENGINE is freed, we have a memory
131 * leak problem to solve. We can't declare a "new" handler for the ex_data as
132 * we don't want a dynamic_data_ctx in *all* ENGINE structures of all types
133 * (this is a bug in the design of CRYPTO_EX_DATA). As such, we just declare
134 * a "free" handler and that will get called if an ENGINE is being destroyed
135 * and there was an ex_data element corresponding to our context type.
137 static void dynamic_data_ctx_free_func(void *parent, void *ptr,
138 CRYPTO_EX_DATA *ad, int idx, long argl,
142 dynamic_data_ctx *ctx = (dynamic_data_ctx *)ptr;
143 DSO_free(ctx->dynamic_dso);
144 OPENSSL_free(ctx->DYNAMIC_LIBNAME);
145 OPENSSL_free(ctx->engine_id);
146 sk_OPENSSL_STRING_pop_free(ctx->dirs, int_free_str);
152 * Construct the per-ENGINE context. We create it blindly and then use a lock
153 * to check for a race - if so, all but one of the threads "racing" will have
154 * wasted their time. The alternative involves creating everything inside the
155 * lock which is far worse.
157 static int dynamic_set_data_ctx(ENGINE *e, dynamic_data_ctx **ctx)
159 dynamic_data_ctx *c = OPENSSL_zalloc(sizeof(*c));
163 ERR_raise(ERR_LIB_ENGINE, ERR_R_MALLOC_FAILURE);
166 c->dirs = sk_OPENSSL_STRING_new_null();
167 if (c->dirs == NULL) {
168 ERR_raise(ERR_LIB_ENGINE, ERR_R_MALLOC_FAILURE);
171 c->DYNAMIC_F1 = "v_check";
172 c->DYNAMIC_F2 = "bind_engine";
174 if (!CRYPTO_THREAD_write_lock(global_engine_lock))
176 if ((*ctx = (dynamic_data_ctx *)ENGINE_get_ex_data(e,
177 dynamic_ex_data_idx))
179 /* Good, we're the first */
180 ret = ENGINE_set_ex_data(e, dynamic_ex_data_idx, c);
186 CRYPTO_THREAD_unlock(global_engine_lock);
189 * If we lost the race to set the context, c is non-NULL and *ctx is the
190 * context of the thread that won.
194 sk_OPENSSL_STRING_free(c->dirs);
200 * This function retrieves the context structure from an ENGINE's "ex_data",
201 * or if it doesn't exist yet, sets it up.
203 static dynamic_data_ctx *dynamic_get_data_ctx(ENGINE *e)
205 dynamic_data_ctx *ctx;
206 if (dynamic_ex_data_idx < 0) {
208 * Create and register the ENGINE ex_data, and associate our "free"
209 * function with it to ensure any allocated contexts get freed when
210 * an ENGINE goes underground.
212 int new_idx = ENGINE_get_ex_new_index(0, NULL, NULL, NULL,
213 dynamic_data_ctx_free_func);
215 ERR_raise(ERR_LIB_ENGINE, ENGINE_R_NO_INDEX);
218 if (!CRYPTO_THREAD_write_lock(global_engine_lock))
220 /* Avoid a race by checking again inside this lock */
221 if (dynamic_ex_data_idx < 0) {
222 /* Good, someone didn't beat us to it */
223 dynamic_ex_data_idx = new_idx;
226 CRYPTO_THREAD_unlock(global_engine_lock);
228 * In theory we could "give back" the index here if (new_idx>-1), but
229 * it's not possible and wouldn't gain us much if it were.
232 ctx = (dynamic_data_ctx *)ENGINE_get_ex_data(e, dynamic_ex_data_idx);
233 /* Check if the context needs to be created */
234 if ((ctx == NULL) && !dynamic_set_data_ctx(e, &ctx))
235 /* "set_data" will set errors if necessary */
240 static ENGINE *engine_dynamic(void)
242 ENGINE *ret = ENGINE_new();
245 if (!ENGINE_set_id(ret, engine_dynamic_id) ||
246 !ENGINE_set_name(ret, engine_dynamic_name) ||
247 !ENGINE_set_init_function(ret, dynamic_init) ||
248 !ENGINE_set_finish_function(ret, dynamic_finish) ||
249 !ENGINE_set_ctrl_function(ret, dynamic_ctrl) ||
250 !ENGINE_set_flags(ret, ENGINE_FLAGS_BY_ID_COPY) ||
251 !ENGINE_set_cmd_defns(ret, dynamic_cmd_defns)) {
258 void engine_load_dynamic_int(void)
260 ENGINE *toadd = engine_dynamic();
267 * If the "add" worked, it gets a structural reference. So either way, we
268 * release our just-created reference.
272 * If the "add" didn't work, it was probably a conflict because it was
273 * already added (eg. someone calling ENGINE_load_blah then calling
274 * ENGINE_load_builtin_engines() perhaps).
279 static int dynamic_init(ENGINE *e)
282 * We always return failure - the "dynamic" engine itself can't be used
288 static int dynamic_finish(ENGINE *e)
291 * This should never be called on account of "dynamic_init" always
297 static int dynamic_ctrl(ENGINE *e, int cmd, long i, void *p, void (*f) (void))
299 dynamic_data_ctx *ctx = dynamic_get_data_ctx(e);
303 ERR_raise(ERR_LIB_ENGINE, ENGINE_R_NOT_LOADED);
306 initialised = ((ctx->dynamic_dso == NULL) ? 0 : 1);
307 /* All our control commands require the ENGINE to be uninitialised */
309 ERR_raise(ERR_LIB_ENGINE, ENGINE_R_ALREADY_LOADED);
313 case DYNAMIC_CMD_SO_PATH:
314 /* a NULL 'p' or a string of zero-length is the same thing */
315 if (p && (strlen((const char *)p) < 1))
317 OPENSSL_free(ctx->DYNAMIC_LIBNAME);
319 ctx->DYNAMIC_LIBNAME = OPENSSL_strdup(p);
321 ctx->DYNAMIC_LIBNAME = NULL;
322 return (ctx->DYNAMIC_LIBNAME ? 1 : 0);
323 case DYNAMIC_CMD_NO_VCHECK:
324 ctx->no_vcheck = ((i == 0) ? 0 : 1);
327 /* a NULL 'p' or a string of zero-length is the same thing */
328 if (p && (strlen((const char *)p) < 1))
330 OPENSSL_free(ctx->engine_id);
332 ctx->engine_id = OPENSSL_strdup(p);
334 ctx->engine_id = NULL;
335 return (ctx->engine_id ? 1 : 0);
336 case DYNAMIC_CMD_LIST_ADD:
337 if ((i < 0) || (i > 2)) {
338 ERR_raise(ERR_LIB_ENGINE, ENGINE_R_INVALID_ARGUMENT);
341 ctx->list_add_value = (int)i;
343 case DYNAMIC_CMD_LOAD:
344 return dynamic_load(e, ctx);
345 case DYNAMIC_CMD_DIR_LOAD:
346 if ((i < 0) || (i > 2)) {
347 ERR_raise(ERR_LIB_ENGINE, ENGINE_R_INVALID_ARGUMENT);
350 ctx->dir_load = (int)i;
352 case DYNAMIC_CMD_DIR_ADD:
353 /* a NULL 'p' or a string of zero-length is the same thing */
354 if (p == NULL || (strlen((const char *)p) < 1)) {
355 ERR_raise(ERR_LIB_ENGINE, ENGINE_R_INVALID_ARGUMENT);
359 char *tmp_str = OPENSSL_strdup(p);
360 if (tmp_str == NULL) {
361 ERR_raise(ERR_LIB_ENGINE, ERR_R_MALLOC_FAILURE);
364 if (!sk_OPENSSL_STRING_push(ctx->dirs, tmp_str)) {
365 OPENSSL_free(tmp_str);
366 ERR_raise(ERR_LIB_ENGINE, ERR_R_MALLOC_FAILURE);
374 ERR_raise(ERR_LIB_ENGINE, ENGINE_R_CTRL_COMMAND_NOT_IMPLEMENTED);
378 static int int_load(dynamic_data_ctx *ctx)
381 /* Unless told not to, try a direct load */
382 if ((ctx->dir_load != 2) && (DSO_load(ctx->dynamic_dso,
383 ctx->DYNAMIC_LIBNAME, NULL,
386 /* If we're not allowed to use 'dirs' or we have none, fail */
387 if (!ctx->dir_load || (num = sk_OPENSSL_STRING_num(ctx->dirs)) < 1)
389 for (loop = 0; loop < num; loop++) {
390 const char *s = sk_OPENSSL_STRING_value(ctx->dirs, loop);
391 char *merge = DSO_merge(ctx->dynamic_dso, ctx->DYNAMIC_LIBNAME, s);
394 if (DSO_load(ctx->dynamic_dso, merge, NULL, 0)) {
395 /* Found what we're looking for */
404 static int dynamic_load(ENGINE *e, dynamic_data_ctx *ctx)
409 if (ctx->dynamic_dso == NULL)
410 ctx->dynamic_dso = DSO_new();
411 if (ctx->dynamic_dso == NULL)
413 if (!ctx->DYNAMIC_LIBNAME) {
416 DSO_ctrl(ctx->dynamic_dso, DSO_CTRL_SET_FLAGS,
417 DSO_FLAG_NAME_TRANSLATION_EXT_ONLY, NULL);
418 ctx->DYNAMIC_LIBNAME =
419 DSO_convert_filename(ctx->dynamic_dso, ctx->engine_id);
421 if (!int_load(ctx)) {
422 ERR_raise(ERR_LIB_ENGINE, ENGINE_R_DSO_NOT_FOUND);
423 DSO_free(ctx->dynamic_dso);
424 ctx->dynamic_dso = NULL;
427 /* We have to find a bind function otherwise it'll always end badly */
430 (dynamic_bind_engine) DSO_bind_func(ctx->dynamic_dso,
432 ctx->bind_engine = NULL;
433 DSO_free(ctx->dynamic_dso);
434 ctx->dynamic_dso = NULL;
435 ERR_raise(ERR_LIB_ENGINE, ENGINE_R_DSO_FAILURE);
438 /* Do we perform version checking? */
439 if (!ctx->no_vcheck) {
440 unsigned long vcheck_res = 0;
442 * Now we try to find a version checking function and decide how to
443 * cope with failure if/when it fails.
446 (dynamic_v_check_fn) DSO_bind_func(ctx->dynamic_dso,
449 vcheck_res = ctx->v_check(OSSL_DYNAMIC_VERSION);
451 * We fail if the version checker veto'd the load *or* if it is
452 * deferring to us (by returning its version) and we think it is too
455 if (vcheck_res < OSSL_DYNAMIC_OLDEST) {
457 ctx->bind_engine = NULL;
459 DSO_free(ctx->dynamic_dso);
460 ctx->dynamic_dso = NULL;
461 ERR_raise(ERR_LIB_ENGINE, ENGINE_R_VERSION_INCOMPATIBILITY);
466 * First binary copy the ENGINE structure so that we can roll back if the
469 memcpy(&cpy, e, sizeof(ENGINE));
471 * Provide the ERR, "ex_data", memory, and locking callbacks so the
472 * loaded library uses our state rather than its own. FIXME: As noted in
473 * engine.h, much of this would be simplified if each area of code
474 * provided its own "summary" structure of all related callbacks. It
475 * would also increase opaqueness.
477 fns.static_state = ENGINE_get_static_state();
478 CRYPTO_get_mem_functions(&fns.mem_fns.malloc_fn, &fns.mem_fns.realloc_fn,
479 &fns.mem_fns.free_fn);
481 * Now that we've loaded the dynamic engine, make sure no "dynamic"
482 * ENGINE elements will show through.
484 engine_set_all_null(e);
486 /* Try to bind the ENGINE onto our own ENGINE structure */
487 if (!ctx->bind_engine(e, ctx->engine_id, &fns)) {
488 ctx->bind_engine = NULL;
490 DSO_free(ctx->dynamic_dso);
491 ctx->dynamic_dso = NULL;
492 ERR_raise(ERR_LIB_ENGINE, ENGINE_R_INIT_FAILED);
493 /* Copy the original ENGINE structure back */
494 memcpy(e, &cpy, sizeof(ENGINE));
497 /* Do we try to add this ENGINE to the internal list too? */
498 if (ctx->list_add_value > 0) {
499 if (!ENGINE_add(e)) {
500 /* Do we tolerate this or fail? */
501 if (ctx->list_add_value > 1) {
503 * Fail - NB: By this time, it's too late to rollback, and
504 * trying to do so allows the bind_engine() code to have
505 * created leaks. We just have to fail where we are, after
506 * the ENGINE has changed.
508 ERR_raise(ERR_LIB_ENGINE, ENGINE_R_CONFLICTING_ENGINE_ID);