1 /* crypto/engine/eng_dyn.c */
3 * Written by Geoff Thorpe (geoff@geoffthorpe.net) for the OpenSSL project
6 /* ====================================================================
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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).
61 #include <openssl/dso.h>
64 * Shared libraries implementing ENGINEs for use by the "dynamic" ENGINE
65 * loader should implement the hook-up functions with the following
69 /* Our ENGINE handlers */
70 static int dynamic_init(ENGINE *e);
71 static int dynamic_finish(ENGINE *e);
72 static int dynamic_ctrl(ENGINE *e, int cmd, long i, void *p,
74 /* Predeclare our context type */
75 typedef struct st_dynamic_data_ctx dynamic_data_ctx;
76 /* The implementation for the important control command */
77 static int dynamic_load(ENGINE *e, dynamic_data_ctx *ctx);
79 #define DYNAMIC_CMD_SO_PATH ENGINE_CMD_BASE
80 #define DYNAMIC_CMD_NO_VCHECK (ENGINE_CMD_BASE + 1)
81 #define DYNAMIC_CMD_ID (ENGINE_CMD_BASE + 2)
82 #define DYNAMIC_CMD_LIST_ADD (ENGINE_CMD_BASE + 3)
83 #define DYNAMIC_CMD_DIR_LOAD (ENGINE_CMD_BASE + 4)
84 #define DYNAMIC_CMD_DIR_ADD (ENGINE_CMD_BASE + 5)
85 #define DYNAMIC_CMD_LOAD (ENGINE_CMD_BASE + 6)
87 /* The constants used when creating the ENGINE */
88 static const char *engine_dynamic_id = "dynamic";
89 static const char *engine_dynamic_name = "Dynamic engine loading support";
90 static const ENGINE_CMD_DEFN dynamic_cmd_defns[] = {
93 "Specifies the path to the new ENGINE shared library",
94 ENGINE_CMD_FLAG_STRING},
95 {DYNAMIC_CMD_NO_VCHECK,
97 "Specifies to continue even if version checking fails (boolean)",
98 ENGINE_CMD_FLAG_NUMERIC},
101 "Specifies an ENGINE id name for loading",
102 ENGINE_CMD_FLAG_STRING},
103 {DYNAMIC_CMD_LIST_ADD,
105 "Whether to add a loaded ENGINE to the internal list (0=no,1=yes,2=mandatory)",
106 ENGINE_CMD_FLAG_NUMERIC},
107 {DYNAMIC_CMD_DIR_LOAD,
109 "Specifies whether to load from 'DIR_ADD' directories (0=no,1=yes,2=mandatory)",
110 ENGINE_CMD_FLAG_NUMERIC},
111 {DYNAMIC_CMD_DIR_ADD,
113 "Adds a directory from which ENGINEs can be loaded",
114 ENGINE_CMD_FLAG_STRING},
117 "Load up the ENGINE specified by other settings",
118 ENGINE_CMD_FLAG_NO_INPUT},
123 * Loading code stores state inside the ENGINE structure via the "ex_data"
124 * element. We load all our state into a single structure and use that as a
125 * single context in the "ex_data" stack.
127 struct st_dynamic_data_ctx {
128 /* The DSO object we load that supplies the ENGINE code */
131 * The function pointer to the version checking shared library function
133 dynamic_v_check_fn v_check;
135 * The function pointer to the engine-binding shared library function
137 dynamic_bind_engine bind_engine;
138 /* The default name/path for loading the shared library */
139 const char *DYNAMIC_LIBNAME;
140 /* Whether to continue loading on a version check failure */
142 /* If non-NULL, stipulates the 'id' of the ENGINE to be loaded */
143 const char *engine_id;
145 * If non-zero, a successfully loaded ENGINE should be added to the
146 * internal ENGINE list. If 2, the add must succeed or the entire load
150 /* The symbol name for the version checking function */
151 const char *DYNAMIC_F1;
152 /* The symbol name for the "initialise ENGINE structure" function */
153 const char *DYNAMIC_F2;
155 * Whether to never use 'dirs', use 'dirs' as a fallback, or only use
156 * 'dirs' for loading. Default is to use 'dirs' as a fallback.
159 /* A stack of directories from which ENGINEs could be loaded */
160 STACK_OF(OPENSSL_STRING) *dirs;
164 * This is the "ex_data" index we obtain and reserve for use with our context
167 static int dynamic_ex_data_idx = -1;
169 static void int_free_str(char *s)
175 * Because our ex_data element may or may not get allocated depending on
176 * whether a "first-use" occurs before the ENGINE is freed, we have a memory
177 * leak problem to solve. We can't declare a "new" handler for the ex_data as
178 * we don't want a dynamic_data_ctx in *all* ENGINE structures of all types
179 * (this is a bug in the design of CRYPTO_EX_DATA). As such, we just declare
180 * a "free" handler and that will get called if an ENGINE is being destroyed
181 * and there was an ex_data element corresponding to our context type.
183 static void dynamic_data_ctx_free_func(void *parent, void *ptr,
184 CRYPTO_EX_DATA *ad, int idx, long argl,
188 dynamic_data_ctx *ctx = (dynamic_data_ctx *)ptr;
189 if (ctx->dynamic_dso)
190 DSO_free(ctx->dynamic_dso);
191 if (ctx->DYNAMIC_LIBNAME)
192 OPENSSL_free((void *)ctx->DYNAMIC_LIBNAME);
194 OPENSSL_free((void *)ctx->engine_id);
196 sk_OPENSSL_STRING_pop_free(ctx->dirs, int_free_str);
202 * Construct the per-ENGINE context. We create it blindly and then use a lock
203 * to check for a race - if so, all but one of the threads "racing" will have
204 * wasted their time. The alternative involves creating everything inside the
205 * lock which is far worse.
207 static int dynamic_set_data_ctx(ENGINE *e, dynamic_data_ctx **ctx)
210 c = OPENSSL_malloc(sizeof(dynamic_data_ctx));
212 ENGINEerr(ENGINE_F_DYNAMIC_SET_DATA_CTX, ERR_R_MALLOC_FAILURE);
215 memset(c, 0, sizeof(dynamic_data_ctx));
216 c->dynamic_dso = NULL;
218 c->bind_engine = NULL;
219 c->DYNAMIC_LIBNAME = NULL;
222 c->list_add_value = 0;
223 c->DYNAMIC_F1 = "v_check";
224 c->DYNAMIC_F2 = "bind_engine";
226 c->dirs = sk_OPENSSL_STRING_new_null();
228 ENGINEerr(ENGINE_F_DYNAMIC_SET_DATA_CTX, ERR_R_MALLOC_FAILURE);
232 CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
233 if ((*ctx = (dynamic_data_ctx *)ENGINE_get_ex_data(e,
234 dynamic_ex_data_idx))
236 /* Good, we're the first */
237 ENGINE_set_ex_data(e, dynamic_ex_data_idx, c);
241 CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
243 * If we lost the race to set the context, c is non-NULL and *ctx is the
244 * context of the thread that won.
252 * This function retrieves the context structure from an ENGINE's "ex_data",
253 * or if it doesn't exist yet, sets it up.
255 static dynamic_data_ctx *dynamic_get_data_ctx(ENGINE *e)
257 dynamic_data_ctx *ctx;
258 if (dynamic_ex_data_idx < 0) {
260 * Create and register the ENGINE ex_data, and associate our "free"
261 * function with it to ensure any allocated contexts get freed when
262 * an ENGINE goes underground.
264 int new_idx = ENGINE_get_ex_new_index(0, NULL, NULL, NULL,
265 dynamic_data_ctx_free_func);
267 ENGINEerr(ENGINE_F_DYNAMIC_GET_DATA_CTX, ENGINE_R_NO_INDEX);
270 CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
271 /* Avoid a race by checking again inside this lock */
272 if (dynamic_ex_data_idx < 0) {
273 /* Good, someone didn't beat us to it */
274 dynamic_ex_data_idx = new_idx;
277 CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
279 * In theory we could "give back" the index here if (new_idx>-1), but
280 * it's not possible and wouldn't gain us much if it were.
283 ctx = (dynamic_data_ctx *)ENGINE_get_ex_data(e, dynamic_ex_data_idx);
284 /* Check if the context needs to be created */
285 if ((ctx == NULL) && !dynamic_set_data_ctx(e, &ctx))
286 /* "set_data" will set errors if necessary */
291 static ENGINE *engine_dynamic(void)
293 ENGINE *ret = ENGINE_new();
296 if (!ENGINE_set_id(ret, engine_dynamic_id) ||
297 !ENGINE_set_name(ret, engine_dynamic_name) ||
298 !ENGINE_set_init_function(ret, dynamic_init) ||
299 !ENGINE_set_finish_function(ret, dynamic_finish) ||
300 !ENGINE_set_ctrl_function(ret, dynamic_ctrl) ||
301 !ENGINE_set_flags(ret, ENGINE_FLAGS_BY_ID_COPY) ||
302 !ENGINE_set_cmd_defns(ret, dynamic_cmd_defns)) {
309 void ENGINE_load_dynamic(void)
311 ENGINE *toadd = engine_dynamic();
316 * If the "add" worked, it gets a structural reference. So either way, we
317 * release our just-created reference.
321 * If the "add" didn't work, it was probably a conflict because it was
322 * already added (eg. someone calling ENGINE_load_blah then calling
323 * ENGINE_load_builtin_engines() perhaps).
328 static int dynamic_init(ENGINE *e)
331 * We always return failure - the "dyanamic" engine itself can't be used
337 static int dynamic_finish(ENGINE *e)
340 * This should never be called on account of "dynamic_init" always
346 static int dynamic_ctrl(ENGINE *e, int cmd, long i, void *p, void (*f) (void))
348 dynamic_data_ctx *ctx = dynamic_get_data_ctx(e);
352 ENGINEerr(ENGINE_F_DYNAMIC_CTRL, ENGINE_R_NOT_LOADED);
355 initialised = ((ctx->dynamic_dso == NULL) ? 0 : 1);
356 /* All our control commands require the ENGINE to be uninitialised */
358 ENGINEerr(ENGINE_F_DYNAMIC_CTRL, ENGINE_R_ALREADY_LOADED);
362 case DYNAMIC_CMD_SO_PATH:
363 /* a NULL 'p' or a string of zero-length is the same thing */
364 if (p && (strlen((const char *)p) < 1))
366 if (ctx->DYNAMIC_LIBNAME)
367 OPENSSL_free((void *)ctx->DYNAMIC_LIBNAME);
369 ctx->DYNAMIC_LIBNAME = BUF_strdup(p);
371 ctx->DYNAMIC_LIBNAME = NULL;
372 return (ctx->DYNAMIC_LIBNAME ? 1 : 0);
373 case DYNAMIC_CMD_NO_VCHECK:
374 ctx->no_vcheck = ((i == 0) ? 0 : 1);
377 /* a NULL 'p' or a string of zero-length is the same thing */
378 if (p && (strlen((const char *)p) < 1))
381 OPENSSL_free((void *)ctx->engine_id);
383 ctx->engine_id = BUF_strdup(p);
385 ctx->engine_id = NULL;
386 return (ctx->engine_id ? 1 : 0);
387 case DYNAMIC_CMD_LIST_ADD:
388 if ((i < 0) || (i > 2)) {
389 ENGINEerr(ENGINE_F_DYNAMIC_CTRL, ENGINE_R_INVALID_ARGUMENT);
392 ctx->list_add_value = (int)i;
394 case DYNAMIC_CMD_LOAD:
395 return dynamic_load(e, ctx);
396 case DYNAMIC_CMD_DIR_LOAD:
397 if ((i < 0) || (i > 2)) {
398 ENGINEerr(ENGINE_F_DYNAMIC_CTRL, ENGINE_R_INVALID_ARGUMENT);
401 ctx->dir_load = (int)i;
403 case DYNAMIC_CMD_DIR_ADD:
404 /* a NULL 'p' or a string of zero-length is the same thing */
405 if (!p || (strlen((const char *)p) < 1)) {
406 ENGINEerr(ENGINE_F_DYNAMIC_CTRL, ENGINE_R_INVALID_ARGUMENT);
410 char *tmp_str = BUF_strdup(p);
412 ENGINEerr(ENGINE_F_DYNAMIC_CTRL, ERR_R_MALLOC_FAILURE);
415 sk_OPENSSL_STRING_insert(ctx->dirs, tmp_str, -1);
421 ENGINEerr(ENGINE_F_DYNAMIC_CTRL, ENGINE_R_CTRL_COMMAND_NOT_IMPLEMENTED);
425 static int int_load(dynamic_data_ctx *ctx)
428 /* Unless told not to, try a direct load */
429 if ((ctx->dir_load != 2) && (DSO_load(ctx->dynamic_dso,
430 ctx->DYNAMIC_LIBNAME, NULL,
433 /* If we're not allowed to use 'dirs' or we have none, fail */
434 if (!ctx->dir_load || (num = sk_OPENSSL_STRING_num(ctx->dirs)) < 1)
436 for (loop = 0; loop < num; loop++) {
437 const char *s = sk_OPENSSL_STRING_value(ctx->dirs, loop);
438 char *merge = DSO_merge(ctx->dynamic_dso, ctx->DYNAMIC_LIBNAME, s);
441 if (DSO_load(ctx->dynamic_dso, merge, NULL, 0)) {
442 /* Found what we're looking for */
451 static int dynamic_load(ENGINE *e, dynamic_data_ctx *ctx)
456 if (!ctx->dynamic_dso)
457 ctx->dynamic_dso = DSO_new();
458 if (!ctx->DYNAMIC_LIBNAME) {
461 ctx->DYNAMIC_LIBNAME =
462 DSO_convert_filename(ctx->dynamic_dso, ctx->engine_id);
464 if (!int_load(ctx)) {
465 ENGINEerr(ENGINE_F_DYNAMIC_LOAD, ENGINE_R_DSO_NOT_FOUND);
466 DSO_free(ctx->dynamic_dso);
467 ctx->dynamic_dso = NULL;
470 /* We have to find a bind function otherwise it'll always end badly */
473 (dynamic_bind_engine) DSO_bind_func(ctx->dynamic_dso,
475 ctx->bind_engine = NULL;
476 DSO_free(ctx->dynamic_dso);
477 ctx->dynamic_dso = NULL;
478 ENGINEerr(ENGINE_F_DYNAMIC_LOAD, ENGINE_R_DSO_FAILURE);
481 /* Do we perform version checking? */
482 if (!ctx->no_vcheck) {
483 unsigned long vcheck_res = 0;
485 * Now we try to find a version checking function and decide how to
486 * cope with failure if/when it fails.
489 (dynamic_v_check_fn) DSO_bind_func(ctx->dynamic_dso,
492 vcheck_res = ctx->v_check(OSSL_DYNAMIC_VERSION);
494 * We fail if the version checker veto'd the load *or* if it is
495 * deferring to us (by returning its version) and we think it is too
498 if (vcheck_res < OSSL_DYNAMIC_OLDEST) {
500 ctx->bind_engine = NULL;
502 DSO_free(ctx->dynamic_dso);
503 ctx->dynamic_dso = NULL;
504 ENGINEerr(ENGINE_F_DYNAMIC_LOAD,
505 ENGINE_R_VERSION_INCOMPATIBILITY);
510 * First binary copy the ENGINE structure so that we can roll back if the
513 memcpy(&cpy, e, sizeof(ENGINE));
515 * Provide the ERR, "ex_data", memory, and locking callbacks so the
516 * loaded library uses our state rather than its own. FIXME: As noted in
517 * engine.h, much of this would be simplified if each area of code
518 * provided its own "summary" structure of all related callbacks. It
519 * would also increase opaqueness.
521 fns.static_state = ENGINE_get_static_state();
522 fns.err_fns = ERR_get_implementation();
523 fns.ex_data_fns = CRYPTO_get_ex_data_implementation();
524 CRYPTO_get_mem_functions(&fns.mem_fns.malloc_cb,
525 &fns.mem_fns.realloc_cb, &fns.mem_fns.free_cb);
526 fns.lock_fns.lock_locking_cb = CRYPTO_get_locking_callback();
527 fns.lock_fns.lock_add_lock_cb = CRYPTO_get_add_lock_callback();
528 fns.lock_fns.dynlock_create_cb = CRYPTO_get_dynlock_create_callback();
529 fns.lock_fns.dynlock_lock_cb = CRYPTO_get_dynlock_lock_callback();
530 fns.lock_fns.dynlock_destroy_cb = CRYPTO_get_dynlock_destroy_callback();
532 * Now that we've loaded the dynamic engine, make sure no "dynamic"
533 * ENGINE elements will show through.
535 engine_set_all_null(e);
537 /* Try to bind the ENGINE onto our own ENGINE structure */
538 if (!ctx->bind_engine(e, ctx->engine_id, &fns)) {
539 ctx->bind_engine = NULL;
541 DSO_free(ctx->dynamic_dso);
542 ctx->dynamic_dso = NULL;
543 ENGINEerr(ENGINE_F_DYNAMIC_LOAD, ENGINE_R_INIT_FAILED);
544 /* Copy the original ENGINE structure back */
545 memcpy(e, &cpy, sizeof(ENGINE));
548 /* Do we try to add this ENGINE to the internal list too? */
549 if (ctx->list_add_value > 0) {
550 if (!ENGINE_add(e)) {
551 /* Do we tolerate this or fail? */
552 if (ctx->list_add_value > 1) {
554 * Fail - NB: By this time, it's too late to rollback, and
555 * trying to do so allows the bind_engine() code to have
556 * created leaks. We just have to fail where we are, after
557 * the ENGINE has changed.
559 ENGINEerr(ENGINE_F_DYNAMIC_LOAD,
560 ENGINE_R_CONFLICTING_ENGINE_ID);