/* 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).

 *

 */

/*

 © Portions copyright (c) 2006 Nokia Corporation.  All rights reserved.

 */

#include "eng_int.h"

#include <openssl/dso.h>

#if (defined(SYMBIAN) && (defined(__WINSCW__) || defined(__WINS__)))

#include "libcrypto_wsd_macros.h"

#include "libcrypto_wsd.h"

#endif

/* 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 */

#ifndef EMULATOR

static const char *engine_dynamic_id = "dynamic";

static const char *engine_dynamic_name = "Dynamic engine loading support";

#else

static const char *const engine_dynamic_id = "dynamic";

static const char *const engine_dynamic_name = "Dynamic engine loading support";

#endif

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 *dirs;

	};

/* This is the "ex_data" index we obtain and reserve for use with our context

 * structure. */

#ifndef EMULATOR 

static int dynamic_ex_data_idx = -1;

#else

GET_STATIC_VAR_FROM_TLS(dynamic_ex_data_idx,eng_dyn,int)

#define dynamic_ex_data_idx (*GET_WSD_VAR_NAME(dynamic_ex_data_idx,eng_dyn, s)())

#endif

static void int_free_str(void *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_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_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;

	}

EXPORT_C 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_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_num(ctx->dirs)) < 1))

		return 0;

	for(loop = 0; loop < num; loop++)

		{

		const char *s = sk_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);

			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;

	}