2 * Copyright 2001-2016 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 #include "eng_local.h"
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
== NULL
|| (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
);