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},
122 static const ENGINE_CMD_DEFN dynamic_cmd_defns_empty[] = {
127 * Loading code stores state inside the ENGINE structure via the "ex_data"
128 * element. We load all our state into a single structure and use that as a
129 * single context in the "ex_data" stack.
131 struct st_dynamic_data_ctx {
132 /* The DSO object we load that supplies the ENGINE code */
135 * The function pointer to the version checking shared library function
137 dynamic_v_check_fn v_check;
139 * The function pointer to the engine-binding shared library function
141 dynamic_bind_engine bind_engine;
142 /* The default name/path for loading the shared library */
143 const char *DYNAMIC_LIBNAME;
144 /* Whether to continue loading on a version check failure */
146 /* If non-NULL, stipulates the 'id' of the ENGINE to be loaded */
147 const char *engine_id;
149 * If non-zero, a successfully loaded ENGINE should be added to the
150 * internal ENGINE list. If 2, the add must succeed or the entire load
154 /* The symbol name for the version checking function */
155 const char *DYNAMIC_F1;
156 /* The symbol name for the "initialise ENGINE structure" function */
157 const char *DYNAMIC_F2;
159 * Whether to never use 'dirs', use 'dirs' as a fallback, or only use
160 * 'dirs' for loading. Default is to use 'dirs' as a fallback.
163 /* A stack of directories from which ENGINEs could be loaded */
168 * This is the "ex_data" index we obtain and reserve for use with our context
171 static int dynamic_ex_data_idx = -1;
173 static void int_free_str(void *s)
179 * Because our ex_data element may or may not get allocated depending on
180 * whether a "first-use" occurs before the ENGINE is freed, we have a memory
181 * leak problem to solve. We can't declare a "new" handler for the ex_data as
182 * we don't want a dynamic_data_ctx in *all* ENGINE structures of all types
183 * (this is a bug in the design of CRYPTO_EX_DATA). As such, we just declare
184 * a "free" handler and that will get called if an ENGINE is being destroyed
185 * and there was an ex_data element corresponding to our context type.
187 static void dynamic_data_ctx_free_func(void *parent, void *ptr,
188 CRYPTO_EX_DATA *ad, int idx, long argl,
192 dynamic_data_ctx *ctx = (dynamic_data_ctx *)ptr;
193 if (ctx->dynamic_dso)
194 DSO_free(ctx->dynamic_dso);
195 if (ctx->DYNAMIC_LIBNAME)
196 OPENSSL_free((void *)ctx->DYNAMIC_LIBNAME);
198 OPENSSL_free((void *)ctx->engine_id);
200 sk_pop_free(ctx->dirs, int_free_str);
206 * Construct the per-ENGINE context. We create it blindly and then use a lock
207 * to check for a race - if so, all but one of the threads "racing" will have
208 * wasted their time. The alternative involves creating everything inside the
209 * lock which is far worse.
211 static int dynamic_set_data_ctx(ENGINE *e, dynamic_data_ctx **ctx)
214 c = OPENSSL_malloc(sizeof(dynamic_data_ctx));
216 ENGINEerr(ENGINE_F_DYNAMIC_SET_DATA_CTX, ERR_R_MALLOC_FAILURE);
219 memset(c, 0, sizeof(dynamic_data_ctx));
220 c->dynamic_dso = NULL;
222 c->bind_engine = NULL;
223 c->DYNAMIC_LIBNAME = NULL;
226 c->list_add_value = 0;
227 c->DYNAMIC_F1 = "v_check";
228 c->DYNAMIC_F2 = "bind_engine";
230 c->dirs = sk_new_null();
232 ENGINEerr(ENGINE_F_DYNAMIC_SET_DATA_CTX, ERR_R_MALLOC_FAILURE);
236 CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
237 if ((*ctx = (dynamic_data_ctx *)ENGINE_get_ex_data(e,
238 dynamic_ex_data_idx))
240 /* Good, we're the first */
241 ENGINE_set_ex_data(e, dynamic_ex_data_idx, c);
245 CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
247 * If we lost the race to set the context, c is non-NULL and *ctx is the
248 * context of the thread that won.
256 * This function retrieves the context structure from an ENGINE's "ex_data",
257 * or if it doesn't exist yet, sets it up.
259 static dynamic_data_ctx *dynamic_get_data_ctx(ENGINE *e)
261 dynamic_data_ctx *ctx;
262 if (dynamic_ex_data_idx < 0) {
264 * Create and register the ENGINE ex_data, and associate our "free"
265 * function with it to ensure any allocated contexts get freed when
266 * an ENGINE goes underground.
268 int new_idx = ENGINE_get_ex_new_index(0, NULL, NULL, NULL,
269 dynamic_data_ctx_free_func);
271 ENGINEerr(ENGINE_F_DYNAMIC_GET_DATA_CTX, ENGINE_R_NO_INDEX);
274 CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
275 /* Avoid a race by checking again inside this lock */
276 if (dynamic_ex_data_idx < 0) {
277 /* Good, someone didn't beat us to it */
278 dynamic_ex_data_idx = new_idx;
281 CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
283 * In theory we could "give back" the index here if (new_idx>-1), but
284 * it's not possible and wouldn't gain us much if it were.
287 ctx = (dynamic_data_ctx *)ENGINE_get_ex_data(e, dynamic_ex_data_idx);
288 /* Check if the context needs to be created */
289 if ((ctx == NULL) && !dynamic_set_data_ctx(e, &ctx))
290 /* "set_data" will set errors if necessary */
295 static ENGINE *engine_dynamic(void)
297 ENGINE *ret = ENGINE_new();
300 if (!ENGINE_set_id(ret, engine_dynamic_id) ||
301 !ENGINE_set_name(ret, engine_dynamic_name) ||
302 !ENGINE_set_init_function(ret, dynamic_init) ||
303 !ENGINE_set_finish_function(ret, dynamic_finish) ||
304 !ENGINE_set_ctrl_function(ret, dynamic_ctrl) ||
305 !ENGINE_set_flags(ret, ENGINE_FLAGS_BY_ID_COPY) ||
306 !ENGINE_set_cmd_defns(ret, dynamic_cmd_defns)) {
313 void ENGINE_load_dynamic(void)
315 ENGINE *toadd = engine_dynamic();
320 * If the "add" worked, it gets a structural reference. So either way, we
321 * release our just-created reference.
325 * If the "add" didn't work, it was probably a conflict because it was
326 * already added (eg. someone calling ENGINE_load_blah then calling
327 * ENGINE_load_builtin_engines() perhaps).
332 static int dynamic_init(ENGINE *e)
335 * We always return failure - the "dyanamic" engine itself can't be used
341 static int dynamic_finish(ENGINE *e)
344 * This should never be called on account of "dynamic_init" always
350 static int dynamic_ctrl(ENGINE *e, int cmd, long i, void *p, void (*f) (void))
352 dynamic_data_ctx *ctx = dynamic_get_data_ctx(e);
356 ENGINEerr(ENGINE_F_DYNAMIC_CTRL, ENGINE_R_NOT_LOADED);
359 initialised = ((ctx->dynamic_dso == NULL) ? 0 : 1);
360 /* All our control commands require the ENGINE to be uninitialised */
362 ENGINEerr(ENGINE_F_DYNAMIC_CTRL, ENGINE_R_ALREADY_LOADED);
366 case DYNAMIC_CMD_SO_PATH:
367 /* a NULL 'p' or a string of zero-length is the same thing */
368 if (p && (strlen((const char *)p) < 1))
370 if (ctx->DYNAMIC_LIBNAME)
371 OPENSSL_free((void *)ctx->DYNAMIC_LIBNAME);
373 ctx->DYNAMIC_LIBNAME = BUF_strdup(p);
375 ctx->DYNAMIC_LIBNAME = NULL;
376 return (ctx->DYNAMIC_LIBNAME ? 1 : 0);
377 case DYNAMIC_CMD_NO_VCHECK:
378 ctx->no_vcheck = ((i == 0) ? 0 : 1);
381 /* a NULL 'p' or a string of zero-length is the same thing */
382 if (p && (strlen((const char *)p) < 1))
385 OPENSSL_free((void *)ctx->engine_id);
387 ctx->engine_id = BUF_strdup(p);
389 ctx->engine_id = NULL;
390 return (ctx->engine_id ? 1 : 0);
391 case DYNAMIC_CMD_LIST_ADD:
392 if ((i < 0) || (i > 2)) {
393 ENGINEerr(ENGINE_F_DYNAMIC_CTRL, ENGINE_R_INVALID_ARGUMENT);
396 ctx->list_add_value = (int)i;
398 case DYNAMIC_CMD_LOAD:
399 return dynamic_load(e, ctx);
400 case DYNAMIC_CMD_DIR_LOAD:
401 if ((i < 0) || (i > 2)) {
402 ENGINEerr(ENGINE_F_DYNAMIC_CTRL, ENGINE_R_INVALID_ARGUMENT);
405 ctx->dir_load = (int)i;
407 case DYNAMIC_CMD_DIR_ADD:
408 /* a NULL 'p' or a string of zero-length is the same thing */
409 if (!p || (strlen((const char *)p) < 1)) {
410 ENGINEerr(ENGINE_F_DYNAMIC_CTRL, ENGINE_R_INVALID_ARGUMENT);
414 char *tmp_str = BUF_strdup(p);
416 ENGINEerr(ENGINE_F_DYNAMIC_CTRL, ERR_R_MALLOC_FAILURE);
419 sk_insert(ctx->dirs, tmp_str, -1);
425 ENGINEerr(ENGINE_F_DYNAMIC_CTRL, ENGINE_R_CTRL_COMMAND_NOT_IMPLEMENTED);
429 static int int_load(dynamic_data_ctx *ctx)
432 /* Unless told not to, try a direct load */
433 if ((ctx->dir_load != 2) && (DSO_load(ctx->dynamic_dso,
434 ctx->DYNAMIC_LIBNAME, NULL,
437 /* If we're not allowed to use 'dirs' or we have none, fail */
438 if (!ctx->dir_load || ((num = sk_num(ctx->dirs)) < 1))
440 for (loop = 0; loop < num; loop++) {
441 const char *s = sk_value(ctx->dirs, loop);
442 char *merge = DSO_merge(ctx->dynamic_dso, ctx->DYNAMIC_LIBNAME, s);
445 if (DSO_load(ctx->dynamic_dso, merge, NULL, 0)) {
446 /* Found what we're looking for */
455 static int dynamic_load(ENGINE *e, dynamic_data_ctx *ctx)
460 if (!ctx->dynamic_dso)
461 ctx->dynamic_dso = DSO_new();
462 if (!ctx->DYNAMIC_LIBNAME) {
465 ctx->DYNAMIC_LIBNAME =
466 DSO_convert_filename(ctx->dynamic_dso, ctx->engine_id);
468 if (!int_load(ctx)) {
469 ENGINEerr(ENGINE_F_DYNAMIC_LOAD, ENGINE_R_DSO_NOT_FOUND);
470 DSO_free(ctx->dynamic_dso);
471 ctx->dynamic_dso = NULL;
474 /* We have to find a bind function otherwise it'll always end badly */
477 (dynamic_bind_engine) DSO_bind_func(ctx->dynamic_dso,
479 ctx->bind_engine = NULL;
480 DSO_free(ctx->dynamic_dso);
481 ctx->dynamic_dso = NULL;
482 ENGINEerr(ENGINE_F_DYNAMIC_LOAD, ENGINE_R_DSO_FAILURE);
485 /* Do we perform version checking? */
486 if (!ctx->no_vcheck) {
487 unsigned long vcheck_res = 0;
489 * Now we try to find a version checking function and decide how to
490 * cope with failure if/when it fails.
493 (dynamic_v_check_fn) DSO_bind_func(ctx->dynamic_dso,
496 vcheck_res = ctx->v_check(OSSL_DYNAMIC_VERSION);
498 * We fail if the version checker veto'd the load *or* if it is
499 * deferring to us (by returning its version) and we think it is too
502 if (vcheck_res < OSSL_DYNAMIC_OLDEST) {
504 ctx->bind_engine = NULL;
506 DSO_free(ctx->dynamic_dso);
507 ctx->dynamic_dso = NULL;
508 ENGINEerr(ENGINE_F_DYNAMIC_LOAD,
509 ENGINE_R_VERSION_INCOMPATIBILITY);
514 * First binary copy the ENGINE structure so that we can roll back if the
517 memcpy(&cpy, e, sizeof(ENGINE));
519 * Provide the ERR, "ex_data", memory, and locking callbacks so the
520 * loaded library uses our state rather than its own. FIXME: As noted in
521 * engine.h, much of this would be simplified if each area of code
522 * provided its own "summary" structure of all related callbacks. It
523 * would also increase opaqueness.
525 fns.static_state = ENGINE_get_static_state();
526 fns.err_fns = ERR_get_implementation();
527 fns.ex_data_fns = CRYPTO_get_ex_data_implementation();
528 CRYPTO_get_mem_functions(&fns.mem_fns.malloc_cb,
529 &fns.mem_fns.realloc_cb, &fns.mem_fns.free_cb);
530 fns.lock_fns.lock_locking_cb = CRYPTO_get_locking_callback();
531 fns.lock_fns.lock_add_lock_cb = CRYPTO_get_add_lock_callback();
532 fns.lock_fns.dynlock_create_cb = CRYPTO_get_dynlock_create_callback();
533 fns.lock_fns.dynlock_lock_cb = CRYPTO_get_dynlock_lock_callback();
534 fns.lock_fns.dynlock_destroy_cb = CRYPTO_get_dynlock_destroy_callback();
536 * Now that we've loaded the dynamic engine, make sure no "dynamic"
537 * ENGINE elements will show through.
539 engine_set_all_null(e);
541 /* Try to bind the ENGINE onto our own ENGINE structure */
542 if (!ctx->bind_engine(e, ctx->engine_id, &fns)) {
543 ctx->bind_engine = NULL;
545 DSO_free(ctx->dynamic_dso);
546 ctx->dynamic_dso = NULL;
547 ENGINEerr(ENGINE_F_DYNAMIC_LOAD, ENGINE_R_INIT_FAILED);
548 /* Copy the original ENGINE structure back */
549 memcpy(e, &cpy, sizeof(ENGINE));
552 /* Do we try to add this ENGINE to the internal list too? */
553 if (ctx->list_add_value > 0) {
554 if (!ENGINE_add(e)) {
555 /* Do we tolerate this or fail? */
556 if (ctx->list_add_value > 1) {
558 * Fail - NB: By this time, it's too late to rollback, and
559 * trying to do so allows the bind_engine() code to have
560 * created leaks. We just have to fail where we are, after
561 * the ENGINE has changed.
563 ENGINEerr(ENGINE_F_DYNAMIC_LOAD,
564 ENGINE_R_CONFLICTING_ENGINE_ID);