eng_dyn.c

开源的ssl算法openssl,版本0.9.8H

			!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_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;
	}