/* crypto/engine/eng_dyn.c */
/* Written by Geoff Thorpe (geoff@geoffthorpe.net) for the OpenSSL
* project 2001.
*/
/* ====================================================================
* Copyright (c) 1999-2001 The OpenSSL Project. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. All advertising materials mentioning features or use of this
* software must display the following acknowledgment:
* "This product includes software developed by the OpenSSL Project
* for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
*
* 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
* endorse or promote products derived from this software without
* prior written permission. For written permission, please contact
* licensing@OpenSSL.org.
*
* 5. Products derived from this software may not be called "OpenSSL"
* nor may "OpenSSL" appear in their names without prior written
* permission of the OpenSSL Project.
*
* 6. Redistributions of any form whatsoever must retain the following
* acknowledgment:
* "This product includes software developed by the OpenSSL Project
* for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
*
* THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
* EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
* ====================================================================
*
* This product includes cryptographic software written by Eric Young
* (eay@cryptsoft.com). This product includes software written by Tim
* Hudson (tjh@cryptsoft.com).
*
*/
#include "eng_int.h"
#include <openssl/dso.h>
/* Shared libraries implementing ENGINEs for use by the "dynamic" ENGINE loader
* should implement the hook-up functions with the following prototypes. */
/* Our ENGINE handlers */
static int dynamic_init(ENGINE *e);
static int dynamic_finish(ENGINE *e);
static int dynamic_ctrl(ENGINE *e, int cmd, long i, void *p, void (*f)(void));
/* Predeclare our context type */
typedef struct st_dynamic_data_ctx dynamic_data_ctx;
/* The implementation for the important control command */
static int dynamic_load(ENGINE *e, dynamic_data_ctx *ctx);
#define DYNAMIC_CMD_SO_PATH ENGINE_CMD_BASE
#define DYNAMIC_CMD_NO_VCHECK (ENGINE_CMD_BASE + 1)
#define DYNAMIC_CMD_ID (ENGINE_CMD_BASE + 2)
#define DYNAMIC_CMD_LIST_ADD (ENGINE_CMD_BASE + 3)
#define DYNAMIC_CMD_DIR_LOAD (ENGINE_CMD_BASE + 4)
#define DYNAMIC_CMD_DIR_ADD (ENGINE_CMD_BASE + 5)
#define DYNAMIC_CMD_LOAD (ENGINE_CMD_BASE + 6)
/* The constants used when creating the ENGINE */
static const char *engine_dynamic_id = "dynamic";
static const char *engine_dynamic_name = "Dynamic engine loading support";
static const ENGINE_CMD_DEFN dynamic_cmd_defns[] = {
{DYNAMIC_CMD_SO_PATH,
"SO_PATH",
"Specifies the path to the new ENGINE shared library",
ENGINE_CMD_FLAG_STRING},
{DYNAMIC_CMD_NO_VCHECK,
"NO_VCHECK",
"Specifies to continue even if version checking fails (boolean)",
ENGINE_CMD_FLAG_NUMERIC},
{DYNAMIC_CMD_ID,
"ID",
"Specifies an ENGINE id name for loading",
ENGINE_CMD_FLAG_STRING},
{DYNAMIC_CMD_LIST_ADD,
"LIST_ADD",
"Whether to add a loaded ENGINE to the internal list (0=no,1=yes,2=mandatory)",
ENGINE_CMD_FLAG_NUMERIC},
{DYNAMIC_CMD_DIR_LOAD,
"DIR_LOAD",
"Specifies whether to load from 'DIR_ADD' directories (0=no,1=yes,2=mandatory)",
ENGINE_CMD_FLAG_NUMERIC},
{DYNAMIC_CMD_DIR_ADD,
"DIR_ADD",
"Adds a directory from which ENGINEs can be loaded",
ENGINE_CMD_FLAG_STRING},
{DYNAMIC_CMD_LOAD,
"LOAD",
"Load up the ENGINE specified by other settings",
ENGINE_CMD_FLAG_NO_INPUT},
{0, NULL, NULL, 0}
};
static const ENGINE_CMD_DEFN dynamic_cmd_defns_empty[] = {
{0, NULL, NULL, 0}
};
/* Loading code stores state inside the ENGINE structure via the "ex_data"
* element. We load all our state into a single structure and use that as a
* single context in the "ex_data" stack. */
struct st_dynamic_data_ctx
{
/* The DSO object we load that supplies the ENGINE code */
DSO *dynamic_dso;
/* The function pointer to the version checking shared library function */
dynamic_v_check_fn v_check;
/* The function pointer to the engine-binding shared library function */
dynamic_bind_engine bind_engine;
/* The default name/path for loading the shared library */
const char *DYNAMIC_LIBNAME;
/* Whether to continue loading on a version check failure */
int no_vcheck;
/* If non-NULL, stipulates the 'id' of the ENGINE to be loaded */
const char *engine_id;
/* If non-zero, a successfully loaded ENGINE should be added to the internal
* ENGINE list. If 2, the add must succeed or the entire load should fail. */
int list_add_value;
/* The symbol name for the version checking function */
const char *DYNAMIC_F1;
/* The symbol name for the "initialise ENGINE structure" function */
const char *DYNAMIC_F2;
/* Whether to never use 'dirs', use 'dirs' as a fallback, or only use
* 'dirs' for loading. Default is to use 'dirs' as a fallback. */
int dir_load;
/* A stack of directories from which ENGINEs could be loaded */
STACK_OF(OPENSSL_STRING) *dirs;
};
/* This is the "ex_data" index we obtain and reserve for use with our context
* structure. */
static int dynamic_ex_data_idx = -1;
static void int_free_str(char *s) { OPENSSL_free(s); }
/* Because our ex_data element may or may not get allocated depending on whether
* a "first-use" occurs before the ENGINE is freed, we have a memory leak
* problem to solve. We can't declare a "new" handler for the ex_data as we
* don't want a dynamic_data_ctx in *all* ENGINE structures of all types (this
* is a bug in the design of CRYPTO_EX_DATA). As such, we just declare a "free"
* handler and that will get called if an ENGINE is being destroyed and there
* was an ex_data element corresponding to our context type. */
static void dynamic_data_ctx_free_func(void *parent, void *ptr,
CRYPTO_EX_DATA *ad, int idx, long argl, void *argp)
{
if(ptr)
{
dynamic_data_ctx *ctx = (dynamic_data_ctx *)ptr;
if(ctx->dynamic_dso)
DSO_free(ctx->dynamic_dso);
if(ctx->DYNAMIC_LIBNAME)
OPENSSL_free((void*)ctx->DYNAMIC_LIBNAME);
if(ctx->engine_id)
OPENSSL_free((void*)ctx->engine_id);
if(ctx->dirs)
sk_OPENSSL_STRING_pop_free(ctx->dirs, int_free_str);
OPENSSL_free(ctx);
}
}
/* Construct the per-ENGINE context. We create it blindly and then use a lock to
* check for a race - if so, all but one of the threads "racing" will have
* wasted their time. The alternative involves creating everything inside the
* lock which is far worse. */
static int dynamic_set_data_ctx(ENGINE *e, dynamic_data_ctx **ctx)
{
dynamic_data_ctx *c;
c = OPENSSL_malloc(sizeof(dynamic_data_ctx));
if(!c)
{
ENGINEerr(ENGINE_F_DYNAMIC_SET_DATA_CTX,ERR_R_MALLOC_FAILURE);
return 0;
}
memset(c, 0, sizeof(dynamic_data_ctx));
c->dynamic_dso = NULL;
c->v_check = NULL;
c->bind_engine = NULL;
c->DYNAMIC_LIBNAME = NULL;
c->no_vcheck = 0;
c->engine_id = NULL;
c->list_add_value = 0;
c->DYNAMIC_F1 = "v_check";
c->DYNAMIC_F2 = "bind_engine";
c->dir_load = 1;
c->dirs = sk_OPENSSL_STRING_new_null();
if(!c->dirs)
{
ENGINEerr(ENGINE_F_DYNAMIC_SET_DATA_CTX,ERR_R_MALLOC_FAILURE);
OPENSSL_free(c);
return 0;
}
CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
if((*ctx = (dynamic_data_ctx *)ENGINE_get_ex_data(e,
dynamic_ex_data_idx)) == NULL)
{
/* Good, we're the first */
ENGINE_set_ex_data(e, dynamic_ex_data_idx, c);
*ctx = c;
c = NULL;
}
CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
/* If we lost the race to set the context, c is non-NULL and *ctx is the
* context of the thread that won. */
if(c)
OPENSSL_free(c);
return 1;
}
/* This function retrieves the context structure from an ENGINE's "ex_data", or
* if it doesn't exist yet, sets it up. */
static dynamic_data_ctx *dynamic_get_data_ctx(ENGINE *e)
{
dynamic_data_ctx *ctx;
if(dynamic_ex_data_idx < 0)
{
/* Create and register the ENGINE ex_data, and associate our
* "free" function with it to ensure any allocated contexts get
* freed when an ENGINE goes underground. */
int new_idx = ENGINE_get_ex_new_index(0, NULL, NULL, NULL,
dynamic_data_ctx_free_func);
if(new_idx == -1)
{
ENGINEerr(ENGINE_F_DYNAMIC_GET_DATA_CTX,ENGINE_R_NO_INDEX);
return NULL;
}
CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
/* Avoid a race by checking again inside this lock */
if(dynamic_ex_data_idx < 0)
{
/* Good, someone didn't beat us to it */
dynamic_ex_data_idx = new_idx;
new_idx = -1;
}
CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
/* In theory we could "give back" the index here if
* (new_idx>-1), but it's not possible and wouldn't gain us much
* if it were. */
}
ctx = (dynamic_data_ctx *)ENGINE_get_ex_data(e, dynamic_ex_data_idx);
/* Check if the context needs to be created */
if((ctx == NULL) && !dynamic_set_data_ctx(e, &ctx))
/* "set_data" will set errors if necessary */
return NULL;
return ctx;
}
static ENGINE *engine_dynamic(void)
{
ENGINE *ret = ENGINE_new();
if(!ret)
return NULL;
if(!ENGINE_set_id(ret, engine_dynamic_id) ||
!ENGINE_set_name(ret, engine_dynamic_name) ||
!ENGINE_set_init_function(ret, dynamic_init) ||
!ENGINE_set_finish_function(ret, dynamic_finish) ||
!ENGINE_set_ctrl_function(ret, dynamic_ctrl) ||
!ENGINE_set_flags(ret, ENGINE_FLAGS_BY_ID_COPY) ||
!ENGINE_set_cmd_defns(ret, dynamic_cmd_defns))
{
ENGINE_free(ret);
return NULL;
}
return ret;
}
void ENGINE_load_dynamic(void)
{
ENGINE *toadd = engine_dynamic();
if(!toadd) return;
ENGINE_add(toadd);
/* If the "add" worked, it gets a structural reference. So either way,
* we release our just-created reference. */
ENGINE_free(toadd);
/* If the "add" didn't work, it was probably a conflict because it was
* already added (eg. someone calling ENGINE_load_blah then calling
* ENGINE_load_builtin_engines() perhaps). */
ERR_clear_error();
}
static int dynamic_init(ENGINE *e)
{
/* We always return failure - the "dyanamic" engine itself can't be used
* for anything. */
return 0;
}
static int dynamic_finish(ENGINE *e)
{
/* This should never be called on account of "dynamic_init" always
* failing. */
return 0;
}
static int dynamic_ctrl(ENGINE *e, int cmd, long i, void *p, void (*f)(void))
{
dynamic_data_ctx *ctx = dynamic_get_data_ctx(e);
int initialised;
if(!ctx)
{
ENGINEerr(ENGINE_F_DYNAMIC_CTRL,ENGINE_R_NOT_LOADED);
return 0;
}
initialised = ((ctx->dynamic_dso == NULL) ? 0 : 1);
/* All our control commands require the ENGINE to be uninitialised */
if(initialised)
{
ENGINEerr(ENGINE_F_DYNAMIC_CTRL,
ENGINE_R_ALREADY_LOADED);
return 0;
}
switch(cmd)
{
case DYNAMIC_CMD_SO_PATH:
/* a NULL 'p' or a string of zero-length is the same thing */
if(p && (strlen((const char *)p) < 1))
p = NULL;
if(ctx->DYNAMIC_LIBNAME)
OPENSSL_free((void*)ctx->DYNAMIC_LIBNAME);
if(p)
ctx->DYNAMIC_LIBNAME = BUF_strdup(p);
else
ctx->DYNAMIC_LIBNAME = NULL;
return (ctx->DYNAMIC_LIBNAME ? 1 : 0);
case DYNAMIC_CMD_NO_VCHECK:
ctx->no_vcheck = ((i == 0) ? 0 : 1);
return 1;
case DYNAMIC_CMD_ID:
/* a NULL 'p' or a string of zero-length is the same thing */
if(p && (strlen((const char *)p) < 1))
p = NULL;
if(ctx->engine_id)
OPENSSL_free((void*)ctx->engine_id);
if(p)
ctx->engine_id = BUF_strdup(p);
else
ctx->engine_id = NULL;
return (ctx->engine_id ? 1 : 0);
case DYNAMIC_CMD_LIST_ADD:
if((i < 0) || (i > 2))
{
ENGINEerr(ENGINE_F_DYNAMIC_CTRL,
ENGINE_R_INVALID_ARGUMENT);
return 0;
}
ctx->list_add_value = (int)i;
return 1;
case DYNAMIC_CMD_LOAD:
return dynamic_load(e, ctx);
case DYNAMIC_CMD_DIR_LOAD:
if((i < 0) || (i > 2))
{
ENGINEerr(ENGINE_F_DYNAMIC_CTRL,
ENGINE_R_INVALID_ARGUMENT);
return 0;
}
ctx->dir_load = (int)i;
return 1;
case DYNAMIC_CMD_DIR_ADD:
/* a NULL 'p' or a string of zero-length is the same thing */
if(!p || (strlen((const char *)p) < 1))
{
ENGINEerr(ENGINE_F_DYNAMIC_CTRL,
ENGINE_R_INVALID_ARGUMENT);
return 0;
}
{
char *tmp_str = BUF_strdup(p);
if(!tmp_str)
{
ENGINEerr(ENGINE_F_DYNAMIC_CTRL,
ERR_R_MALLOC_FAILURE);
return 0;
}
sk_OPENSSL_STRING_insert(ctx->dirs, tmp_str, -1);
}
return 1;
default:
break;
}
ENGINEerr(ENGINE_F_DYNAMIC_CTRL,ENGINE_R_CTRL_COMMAND_NOT_IMPLEMENTED);
return 0;
}
static int int_load(dynamic_data_ctx *ctx)
{
int num, loop;
/* Unless told not to, try a direct load */
if((ctx->dir_load != 2) && (DSO_load(ctx->dynamic_dso,
ctx->DYNAMIC_LIBNAME, NULL, 0) != NULL))
return 1;
/* If we're not allowed to use 'dirs' or we have none, fail */
if(!ctx->dir_load || (num = sk_OPENSSL_STRING_num(ctx->dirs)) < 1)
return 0;
for(loop = 0; loop < num; loop++)
{
const char *s = sk_OPENSSL_STRING_value(ctx->dirs, loop);
char *merge = DSO_merge(ctx->dynamic_dso, ctx->DYNAMIC_LIBNAME, s);
if(!merge)
return 0;
if(DSO_load(ctx->dynamic_dso, merge, NULL, 0))
{
/* Found what we're looking for */
OPENSSL_free(merge);
/* Previous failed loop iterations, if any, will have resulted in
* errors. Clear them out before returning success. */
ERR_clear_error();
return 1;
}
OPENSSL_free(merge);
}
return 0;
}
static int dynamic_load(ENGINE *e, dynamic_data_ctx *ctx)
{
ENGINE cpy;
dynamic_fns fns;
if(!ctx->dynamic_dso)
ctx->dynamic_dso = DSO_new();
if(!ctx->DYNAMIC_LIBNAME)
{
if(!ctx->engine_id)
return 0;
ctx->DYNAMIC_LIBNAME =
DSO_convert_filename(ctx->dynamic_dso, ctx->engine_id);
}
if(!int_load(ctx))
{
ENGINEerr(ENGINE_F_DYNAMIC_LOAD,
ENGINE_R_DSO_NOT_FOUND);
DSO_free(ctx->dynamic_dso);
ctx->dynamic_dso = NULL;
return 0;
}
/* We have to find a bind function otherwise it'll always end badly */
if(!(ctx->bind_engine = (dynamic_bind_engine)DSO_bind_func(
ctx->dynamic_dso, ctx->DYNAMIC_F2)))
{
ctx->bind_engine = NULL;
DSO_free(ctx->dynamic_dso);
ctx->dynamic_dso = NULL;
ENGINEerr(ENGINE_F_DYNAMIC_LOAD,
ENGINE_R_DSO_FAILURE);
return 0;
}
/* Do we perform version checking? */
if(!ctx->no_vcheck)
{
unsigned long vcheck_res = 0;
/* Now we try to find a version checking function and decide how
* to cope with failure if/when it fails. */
ctx->v_check = (dynamic_v_check_fn)DSO_bind_func(
ctx->dynamic_dso, ctx->DYNAMIC_F1);
if(ctx->v_check)
vcheck_res = ctx->v_check(OSSL_DYNAMIC_VERSION);
/* We fail if the version checker veto'd the load *or* if it is
* deferring to us (by returning its version) and we think it is
* too old. */
if(vcheck_res < OSSL_DYNAMIC_OLDEST)
{
/* Fail */
ctx->bind_engine = NULL;
ctx->v_check = NULL;
DSO_free(ctx->dynamic_dso);
ctx->dynamic_dso = NULL;
ENGINEerr(ENGINE_F_DYNAMIC_LOAD,
ENGINE_R_VERSION_INCOMPATIBILITY);
return 0;
}
}
/* First binary copy the ENGINE structure so that we can roll back if
* the hand-over fails */
memcpy(&cpy, e, sizeof(ENGINE));
/* Provide the ERR, "ex_data", memory, and locking callbacks so the
* loaded library uses our state rather than its own. FIXME: As noted in
* engine.h, much of this would be simplified if each area of code
* provided its own "summary" structure of all related callbacks. It
* would also increase opaqueness. */
fns.static_state = ENGINE_get_static_state();
fns.err_fns = ERR_get_implementation();
fns.ex_data_fns = CRYPTO_get_ex_data_implementation();
CRYPTO_get_mem_functions(&fns.mem_fns.malloc_cb,
&fns.mem_fns.realloc_cb,
&fns.mem_fns.free_cb);
fns.lock_fns.lock_locking_cb = CRYPTO_get_locking_callback();
fns.lock_fns.lock_add_lock_cb = CRYPTO_get_add_lock_callback();
fns.lock_fns.dynlock_create_cb = CRYPTO_get_dynlock_create_callback();
fns.lock_fns.dynlock_lock_cb = CRYPTO_get_dynlock_lock_callback();
fns.lock_fns.dynlock_destroy_cb = CRYPTO_get_dynlock_destroy_callback();
/* Now that we've loaded the dynamic engine, make sure no "dynamic"
* ENGINE elements will show through. */
engine_set_all_null(e);
/* Try to bind the ENGINE onto our own ENGINE structure */
if(!ctx->bind_engine(e, ctx->engine_id, &fns))
{
ctx->bind_engine = NULL;
ctx->v_check = NULL;
DSO_free(ctx->dynamic_dso);
ctx->dynamic_dso = NULL;
ENGINEerr(ENGINE_F_DYNAMIC_LOAD,ENGINE_R_INIT_FAILED);
/* Copy the original ENGINE structure back */
memcpy(e, &cpy, sizeof(ENGINE));
return 0;
}
/* Do we try to add this ENGINE to the internal list too? */
if(ctx->list_add_value > 0)
{
if(!ENGINE_add(e))
{
/* Do we tolerate this or fail? */
if(ctx->list_add_value > 1)
{
/* Fail - NB: By this time, it's too late to
* rollback, and trying to do so allows the
* bind_engine() code to have created leaks. We
* just have to fail where we are, after the
* ENGINE has changed. */
ENGINEerr(ENGINE_F_DYNAMIC_LOAD,
ENGINE_R_CONFLICTING_ENGINE_ID);
return 0;
}
/* Tolerate */
ERR_clear_error();
}
}
return 1;
}