2 * Copyright 2001-2016 The OpenSSL Project Authors. All Rights Reserved.
4 * Licensed under the OpenSSL license (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
11 #include "internal/dso.h"
12 #include <openssl/crypto.h>
15 * Shared libraries implementing ENGINEs for use by the "dynamic" ENGINE
16 * loader should implement the hook-up functions with the following
20 /* Our ENGINE handlers */
21 static int dynamic_init(ENGINE *e);
22 static int dynamic_finish(ENGINE *e);
23 static int dynamic_ctrl(ENGINE *e, int cmd, long i, void *p,
25 /* Predeclare our context type */
26 typedef struct st_dynamic_data_ctx dynamic_data_ctx;
27 /* The implementation for the important control command */
28 static int dynamic_load(ENGINE *e, dynamic_data_ctx *ctx);
30 #define DYNAMIC_CMD_SO_PATH ENGINE_CMD_BASE
31 #define DYNAMIC_CMD_NO_VCHECK (ENGINE_CMD_BASE + 1)
32 #define DYNAMIC_CMD_ID (ENGINE_CMD_BASE + 2)
33 #define DYNAMIC_CMD_LIST_ADD (ENGINE_CMD_BASE + 3)
34 #define DYNAMIC_CMD_DIR_LOAD (ENGINE_CMD_BASE + 4)
35 #define DYNAMIC_CMD_DIR_ADD (ENGINE_CMD_BASE + 5)
36 #define DYNAMIC_CMD_LOAD (ENGINE_CMD_BASE + 6)
38 /* The constants used when creating the ENGINE */
39 static const char *engine_dynamic_id = "dynamic";
40 static const char *engine_dynamic_name = "Dynamic engine loading support";
41 static const ENGINE_CMD_DEFN dynamic_cmd_defns[] = {
44 "Specifies the path to the new ENGINE shared library",
45 ENGINE_CMD_FLAG_STRING},
46 {DYNAMIC_CMD_NO_VCHECK,
48 "Specifies to continue even if version checking fails (boolean)",
49 ENGINE_CMD_FLAG_NUMERIC},
52 "Specifies an ENGINE id name for loading",
53 ENGINE_CMD_FLAG_STRING},
54 {DYNAMIC_CMD_LIST_ADD,
56 "Whether to add a loaded ENGINE to the internal list (0=no,1=yes,2=mandatory)",
57 ENGINE_CMD_FLAG_NUMERIC},
58 {DYNAMIC_CMD_DIR_LOAD,
60 "Specifies whether to load from 'DIR_ADD' directories (0=no,1=yes,2=mandatory)",
61 ENGINE_CMD_FLAG_NUMERIC},
64 "Adds a directory from which ENGINEs can be loaded",
65 ENGINE_CMD_FLAG_STRING},
68 "Load up the ENGINE specified by other settings",
69 ENGINE_CMD_FLAG_NO_INPUT},
74 * Loading code stores state inside the ENGINE structure via the "ex_data"
75 * element. We load all our state into a single structure and use that as a
76 * single context in the "ex_data" stack.
78 struct st_dynamic_data_ctx {
79 /* The DSO object we load that supplies the ENGINE code */
82 * The function pointer to the version checking shared library function
84 dynamic_v_check_fn v_check;
86 * The function pointer to the engine-binding shared library function
88 dynamic_bind_engine bind_engine;
89 /* The default name/path for loading the shared library */
90 char *DYNAMIC_LIBNAME;
91 /* Whether to continue loading on a version check failure */
93 /* If non-NULL, stipulates the 'id' of the ENGINE to be loaded */
96 * If non-zero, a successfully loaded ENGINE should be added to the
97 * internal ENGINE list. If 2, the add must succeed or the entire load
101 /* The symbol name for the version checking function */
102 const char *DYNAMIC_F1;
103 /* The symbol name for the "initialise ENGINE structure" function */
104 const char *DYNAMIC_F2;
106 * Whether to never use 'dirs', use 'dirs' as a fallback, or only use
107 * 'dirs' for loading. Default is to use 'dirs' as a fallback.
110 /* A stack of directories from which ENGINEs could be loaded */
111 STACK_OF(OPENSSL_STRING) *dirs;
115 * This is the "ex_data" index we obtain and reserve for use with our context
118 static int dynamic_ex_data_idx = -1;
120 static void int_free_str(char *s)
126 * Because our ex_data element may or may not get allocated depending on
127 * whether a "first-use" occurs before the ENGINE is freed, we have a memory
128 * leak problem to solve. We can't declare a "new" handler for the ex_data as
129 * we don't want a dynamic_data_ctx in *all* ENGINE structures of all types
130 * (this is a bug in the design of CRYPTO_EX_DATA). As such, we just declare
131 * a "free" handler and that will get called if an ENGINE is being destroyed
132 * and there was an ex_data element corresponding to our context type.
134 static void dynamic_data_ctx_free_func(void *parent, void *ptr,
135 CRYPTO_EX_DATA *ad, int idx, long argl,
139 dynamic_data_ctx *ctx = (dynamic_data_ctx *)ptr;
140 DSO_free(ctx->dynamic_dso);
141 OPENSSL_free(ctx->DYNAMIC_LIBNAME);
142 OPENSSL_free(ctx->engine_id);
143 sk_OPENSSL_STRING_pop_free(ctx->dirs, int_free_str);
149 * Construct the per-ENGINE context. We create it blindly and then use a lock
150 * to check for a race - if so, all but one of the threads "racing" will have
151 * wasted their time. The alternative involves creating everything inside the
152 * lock which is far worse.
154 static int dynamic_set_data_ctx(ENGINE *e, dynamic_data_ctx **ctx)
156 dynamic_data_ctx *c = OPENSSL_zalloc(sizeof(*c));
160 ENGINEerr(ENGINE_F_DYNAMIC_SET_DATA_CTX, ERR_R_MALLOC_FAILURE);
163 c->dirs = sk_OPENSSL_STRING_new_null();
164 if (c->dirs == NULL) {
165 ENGINEerr(ENGINE_F_DYNAMIC_SET_DATA_CTX, ERR_R_MALLOC_FAILURE);
169 c->DYNAMIC_F1 = "v_check";
170 c->DYNAMIC_F2 = "bind_engine";
172 CRYPTO_THREAD_write_lock(global_engine_lock);
173 if ((*ctx = (dynamic_data_ctx *)ENGINE_get_ex_data(e,
174 dynamic_ex_data_idx))
176 /* Good, we're the first */
177 ret = ENGINE_set_ex_data(e, dynamic_ex_data_idx, c);
183 CRYPTO_THREAD_unlock(global_engine_lock);
185 * If we lost the race to set the context, c is non-NULL and *ctx is the
186 * context of the thread that won.
189 sk_OPENSSL_STRING_free(c->dirs);
195 * This function retrieves the context structure from an ENGINE's "ex_data",
196 * or if it doesn't exist yet, sets it up.
198 static dynamic_data_ctx *dynamic_get_data_ctx(ENGINE *e)
200 dynamic_data_ctx *ctx;
201 if (dynamic_ex_data_idx < 0) {
203 * Create and register the ENGINE ex_data, and associate our "free"
204 * function with it to ensure any allocated contexts get freed when
205 * an ENGINE goes underground.
207 int new_idx = ENGINE_get_ex_new_index(0, NULL, NULL, NULL,
208 dynamic_data_ctx_free_func);
210 ENGINEerr(ENGINE_F_DYNAMIC_GET_DATA_CTX, ENGINE_R_NO_INDEX);
213 CRYPTO_THREAD_write_lock(global_engine_lock);
214 /* Avoid a race by checking again inside this lock */
215 if (dynamic_ex_data_idx < 0) {
216 /* Good, someone didn't beat us to it */
217 dynamic_ex_data_idx = new_idx;
220 CRYPTO_THREAD_unlock(global_engine_lock);
222 * In theory we could "give back" the index here if (new_idx>-1), but
223 * it's not possible and wouldn't gain us much if it were.
226 ctx = (dynamic_data_ctx *)ENGINE_get_ex_data(e, dynamic_ex_data_idx);
227 /* Check if the context needs to be created */
228 if ((ctx == NULL) && !dynamic_set_data_ctx(e, &ctx))
229 /* "set_data" will set errors if necessary */
234 static ENGINE *engine_dynamic(void)
236 ENGINE *ret = ENGINE_new();
239 if (!ENGINE_set_id(ret, engine_dynamic_id) ||
240 !ENGINE_set_name(ret, engine_dynamic_name) ||
241 !ENGINE_set_init_function(ret, dynamic_init) ||
242 !ENGINE_set_finish_function(ret, dynamic_finish) ||
243 !ENGINE_set_ctrl_function(ret, dynamic_ctrl) ||
244 !ENGINE_set_flags(ret, ENGINE_FLAGS_BY_ID_COPY) ||
245 !ENGINE_set_cmd_defns(ret, dynamic_cmd_defns)) {
252 void engine_load_dynamic_int(void)
254 ENGINE *toadd = engine_dynamic();
259 * If the "add" worked, it gets a structural reference. So either way, we
260 * release our just-created reference.
264 * If the "add" didn't work, it was probably a conflict because it was
265 * already added (eg. someone calling ENGINE_load_blah then calling
266 * ENGINE_load_builtin_engines() perhaps).
271 static int dynamic_init(ENGINE *e)
274 * We always return failure - the "dynamic" engine itself can't be used
280 static int dynamic_finish(ENGINE *e)
283 * This should never be called on account of "dynamic_init" always
289 static int dynamic_ctrl(ENGINE *e, int cmd, long i, void *p, void (*f) (void))
291 dynamic_data_ctx *ctx = dynamic_get_data_ctx(e);
295 ENGINEerr(ENGINE_F_DYNAMIC_CTRL, ENGINE_R_NOT_LOADED);
298 initialised = ((ctx->dynamic_dso == NULL) ? 0 : 1);
299 /* All our control commands require the ENGINE to be uninitialised */
301 ENGINEerr(ENGINE_F_DYNAMIC_CTRL, ENGINE_R_ALREADY_LOADED);
305 case DYNAMIC_CMD_SO_PATH:
306 /* a NULL 'p' or a string of zero-length is the same thing */
307 if (p && (strlen((const char *)p) < 1))
309 OPENSSL_free(ctx->DYNAMIC_LIBNAME);
311 ctx->DYNAMIC_LIBNAME = OPENSSL_strdup(p);
313 ctx->DYNAMIC_LIBNAME = NULL;
314 return (ctx->DYNAMIC_LIBNAME ? 1 : 0);
315 case DYNAMIC_CMD_NO_VCHECK:
316 ctx->no_vcheck = ((i == 0) ? 0 : 1);
319 /* a NULL 'p' or a string of zero-length is the same thing */
320 if (p && (strlen((const char *)p) < 1))
322 OPENSSL_free(ctx->engine_id);
324 ctx->engine_id = OPENSSL_strdup(p);
326 ctx->engine_id = NULL;
327 return (ctx->engine_id ? 1 : 0);
328 case DYNAMIC_CMD_LIST_ADD:
329 if ((i < 0) || (i > 2)) {
330 ENGINEerr(ENGINE_F_DYNAMIC_CTRL, ENGINE_R_INVALID_ARGUMENT);
333 ctx->list_add_value = (int)i;
335 case DYNAMIC_CMD_LOAD:
336 return dynamic_load(e, ctx);
337 case DYNAMIC_CMD_DIR_LOAD:
338 if ((i < 0) || (i > 2)) {
339 ENGINEerr(ENGINE_F_DYNAMIC_CTRL, ENGINE_R_INVALID_ARGUMENT);
342 ctx->dir_load = (int)i;
344 case DYNAMIC_CMD_DIR_ADD:
345 /* a NULL 'p' or a string of zero-length is the same thing */
346 if (!p || (strlen((const char *)p) < 1)) {
347 ENGINEerr(ENGINE_F_DYNAMIC_CTRL, ENGINE_R_INVALID_ARGUMENT);
351 char *tmp_str = OPENSSL_strdup(p);
352 if (tmp_str == NULL) {
353 ENGINEerr(ENGINE_F_DYNAMIC_CTRL, ERR_R_MALLOC_FAILURE);
356 if (!sk_OPENSSL_STRING_push(ctx->dirs, tmp_str)) {
357 OPENSSL_free(tmp_str);
358 ENGINEerr(ENGINE_F_DYNAMIC_CTRL, ERR_R_MALLOC_FAILURE);
366 ENGINEerr(ENGINE_F_DYNAMIC_CTRL, ENGINE_R_CTRL_COMMAND_NOT_IMPLEMENTED);
370 static int int_load(dynamic_data_ctx *ctx)
373 /* Unless told not to, try a direct load */
374 if ((ctx->dir_load != 2) && (DSO_load(ctx->dynamic_dso,
375 ctx->DYNAMIC_LIBNAME, NULL,
378 /* If we're not allowed to use 'dirs' or we have none, fail */
379 if (!ctx->dir_load || (num = sk_OPENSSL_STRING_num(ctx->dirs)) < 1)
381 for (loop = 0; loop < num; loop++) {
382 const char *s = sk_OPENSSL_STRING_value(ctx->dirs, loop);
383 char *merge = DSO_merge(ctx->dynamic_dso, ctx->DYNAMIC_LIBNAME, s);
386 if (DSO_load(ctx->dynamic_dso, merge, NULL, 0)) {
387 /* Found what we're looking for */
396 static int dynamic_load(ENGINE *e, dynamic_data_ctx *ctx)
401 if (ctx->dynamic_dso == NULL)
402 ctx->dynamic_dso = DSO_new();
403 if (ctx->dynamic_dso == NULL)
405 if (!ctx->DYNAMIC_LIBNAME) {
408 DSO_ctrl(ctx->dynamic_dso, DSO_CTRL_SET_FLAGS,
409 DSO_FLAG_NAME_TRANSLATION_EXT_ONLY, NULL);
410 ctx->DYNAMIC_LIBNAME =
411 DSO_convert_filename(ctx->dynamic_dso, ctx->engine_id);
413 if (!int_load(ctx)) {
414 ENGINEerr(ENGINE_F_DYNAMIC_LOAD, ENGINE_R_DSO_NOT_FOUND);
415 DSO_free(ctx->dynamic_dso);
416 ctx->dynamic_dso = NULL;
419 /* We have to find a bind function otherwise it'll always end badly */
422 (dynamic_bind_engine) DSO_bind_func(ctx->dynamic_dso,
424 ctx->bind_engine = NULL;
425 DSO_free(ctx->dynamic_dso);
426 ctx->dynamic_dso = NULL;
427 ENGINEerr(ENGINE_F_DYNAMIC_LOAD, ENGINE_R_DSO_FAILURE);
430 /* Do we perform version checking? */
431 if (!ctx->no_vcheck) {
432 unsigned long vcheck_res = 0;
434 * Now we try to find a version checking function and decide how to
435 * cope with failure if/when it fails.
438 (dynamic_v_check_fn) DSO_bind_func(ctx->dynamic_dso,
441 vcheck_res = ctx->v_check(OSSL_DYNAMIC_VERSION);
443 * We fail if the version checker veto'd the load *or* if it is
444 * deferring to us (by returning its version) and we think it is too
447 if (vcheck_res < OSSL_DYNAMIC_OLDEST) {
449 ctx->bind_engine = NULL;
451 DSO_free(ctx->dynamic_dso);
452 ctx->dynamic_dso = NULL;
453 ENGINEerr(ENGINE_F_DYNAMIC_LOAD,
454 ENGINE_R_VERSION_INCOMPATIBILITY);
459 * First binary copy the ENGINE structure so that we can roll back if the
462 memcpy(&cpy, e, sizeof(ENGINE));
464 * Provide the ERR, "ex_data", memory, and locking callbacks so the
465 * loaded library uses our state rather than its own. FIXME: As noted in
466 * engine.h, much of this would be simplified if each area of code
467 * provided its own "summary" structure of all related callbacks. It
468 * would also increase opaqueness.
470 fns.static_state = ENGINE_get_static_state();
471 CRYPTO_get_mem_functions(&fns.mem_fns.malloc_fn, &fns.mem_fns.realloc_fn,
472 &fns.mem_fns.free_fn);
474 * Now that we've loaded the dynamic engine, make sure no "dynamic"
475 * ENGINE elements will show through.
477 engine_set_all_null(e);
479 /* Try to bind the ENGINE onto our own ENGINE structure */
480 if (!ctx->bind_engine(e, ctx->engine_id, &fns)) {
481 ctx->bind_engine = NULL;
483 DSO_free(ctx->dynamic_dso);
484 ctx->dynamic_dso = NULL;
485 ENGINEerr(ENGINE_F_DYNAMIC_LOAD, ENGINE_R_INIT_FAILED);
486 /* Copy the original ENGINE structure back */
487 memcpy(e, &cpy, sizeof(ENGINE));
490 /* Do we try to add this ENGINE to the internal list too? */
491 if (ctx->list_add_value > 0) {
492 if (!ENGINE_add(e)) {
493 /* Do we tolerate this or fail? */
494 if (ctx->list_add_value > 1) {
496 * Fail - NB: By this time, it's too late to rollback, and
497 * trying to do so allows the bind_engine() code to have
498 * created leaks. We just have to fail where we are, after
499 * the ENGINE has changed.
501 ENGINEerr(ENGINE_F_DYNAMIC_LOAD,
502 ENGINE_R_CONFLICTING_ENGINE_ID);