crypto/engine/eng_ctrl.c - platform/external/openssl - Git at Google

 /* crypto/engine/eng_ctrl.c */
 /* ====================================================================
  * 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"

 /* When querying a ENGINE-specific control command's 'description', this string
  * is used if the ENGINE_CMD_DEFN has cmd_desc set to NULL. */
 static const char *int_no_description = "";

 /* These internal functions handle 'CMD'-related control commands when the
  * ENGINE in question has asked us to take care of it (ie. the ENGINE did not
  * set the ENGINE_FLAGS_MANUAL_CMD_CTRL flag. */

 static int int_ctrl_cmd_is_null(const ENGINE_CMD_DEFN *defn)
 	{
 	if((defn->cmd_num == 0) || (defn->cmd_name == NULL))
 		return 1;
 	return 0;
 	}

 static int int_ctrl_cmd_by_name(const ENGINE_CMD_DEFN *defn, const char *s)
 	{
 	int idx = 0;
 	while(!int_ctrl_cmd_is_null(defn) && (strcmp(defn->cmd_name, s) != 0))
 		{
 		idx++;
 		defn++;
 		}
 	if(int_ctrl_cmd_is_null(defn))
 		/* The given name wasn't found */
 		return -1;
 	return idx;
 	}

 static int int_ctrl_cmd_by_num(const ENGINE_CMD_DEFN *defn, unsigned int num)
 	{
 	int idx = 0;
 	/* NB: It is stipulated that 'cmd_defn' lists are ordered by cmd_num. So
 	 * our searches don't need to take any longer than necessary. */
 	while(!int_ctrl_cmd_is_null(defn) && (defn->cmd_num < num))
 		{
 		idx++;
 		defn++;
 		}
 	if(defn->cmd_num == num)
 		return idx;
 	/* The given cmd_num wasn't found */
 	return -1;
 	}

 static int int_ctrl_helper(ENGINE *e, int cmd, long i, void *p,
 			   void (*f)(void))
 	{
 	int idx;
 	char *s = (char *)p;
 	/* Take care of the easy one first (eg. it requires no searches) */
 	if(cmd == ENGINE_CTRL_GET_FIRST_CMD_TYPE)
 		{
 		if((e->cmd_defns == NULL) || int_ctrl_cmd_is_null(e->cmd_defns))
 			return 0;
 		return e->cmd_defns->cmd_num;
 		}
 	/* One or two commands require that "p" be a valid string buffer */
 	if((cmd == ENGINE_CTRL_GET_CMD_FROM_NAME) ||
 			(cmd == ENGINE_CTRL_GET_NAME_FROM_CMD) ||
 			(cmd == ENGINE_CTRL_GET_DESC_FROM_CMD))
 		{
 		if(s == NULL)
 			{
 			ENGINEerr(ENGINE_F_INT_CTRL_HELPER,
 				ERR_R_PASSED_NULL_PARAMETER);
 			return -1;
 			}
 		}
 	/* Now handle cmd_name -> cmd_num conversion */
 	if(cmd == ENGINE_CTRL_GET_CMD_FROM_NAME)
 		{
 		if((e->cmd_defns == NULL) || ((idx = int_ctrl_cmd_by_name(
 						e->cmd_defns, s)) < 0))
 			{
 			ENGINEerr(ENGINE_F_INT_CTRL_HELPER,
 				ENGINE_R_INVALID_CMD_NAME);
 			return -1;
 			}
 		return e->cmd_defns[idx].cmd_num;
 		}
 	/* For the rest of the commands, the 'long' argument must specify a
 	 * valie command number - so we need to conduct a search. */
 	if((e->cmd_defns == NULL) || ((idx = int_ctrl_cmd_by_num(e->cmd_defns,
 					(unsigned int)i)) < 0))
 		{
 		ENGINEerr(ENGINE_F_INT_CTRL_HELPER,
 			ENGINE_R_INVALID_CMD_NUMBER);
 		return -1;
 		}
 	/* Now the logic splits depending on command type */
 	switch(cmd)
 		{
 	case ENGINE_CTRL_GET_NEXT_CMD_TYPE:
 		idx++;
 		if(int_ctrl_cmd_is_null(e->cmd_defns + idx))
 			/* end-of-list */
 			return 0;
 		else
 			return e->cmd_defns[idx].cmd_num;
 	case ENGINE_CTRL_GET_NAME_LEN_FROM_CMD:
 		return strlen(e->cmd_defns[idx].cmd_name);
 	case ENGINE_CTRL_GET_NAME_FROM_CMD:
 		return BIO_snprintf(s,strlen(e->cmd_defns[idx].cmd_name) + 1,
 				    "%s", e->cmd_defns[idx].cmd_name);
 	case ENGINE_CTRL_GET_DESC_LEN_FROM_CMD:
 		if(e->cmd_defns[idx].cmd_desc)
 			return strlen(e->cmd_defns[idx].cmd_desc);
 		return strlen(int_no_description);
 	case ENGINE_CTRL_GET_DESC_FROM_CMD:
 		if(e->cmd_defns[idx].cmd_desc)
 			return BIO_snprintf(s,
 					    strlen(e->cmd_defns[idx].cmd_desc) + 1,
 					    "%s", e->cmd_defns[idx].cmd_desc);
 		return BIO_snprintf(s, strlen(int_no_description) + 1,"%s",
 				    int_no_description);
 	case ENGINE_CTRL_GET_CMD_FLAGS:
 		return e->cmd_defns[idx].cmd_flags;
 		}
 	/* Shouldn't really be here ... */
 	ENGINEerr(ENGINE_F_INT_CTRL_HELPER,ENGINE_R_INTERNAL_LIST_ERROR);
 	return -1;
 	}

 int ENGINE_ctrl(ENGINE *e, int cmd, long i, void *p, void (*f)(void))
 	{
 	int ctrl_exists, ref_exists;
 	if(e == NULL)
 		{
 		ENGINEerr(ENGINE_F_ENGINE_CTRL,ERR_R_PASSED_NULL_PARAMETER);
 		return 0;
 		}
 	CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
 	ref_exists = ((e->struct_ref > 0) ? 1 : 0);
 	CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
 	ctrl_exists = ((e->ctrl == NULL) ? 0 : 1);
 	if(!ref_exists)
 		{
 		ENGINEerr(ENGINE_F_ENGINE_CTRL,ENGINE_R_NO_REFERENCE);
 		return 0;
 		}
 	/* Intercept any "root-level" commands before trying to hand them on to
 	 * ctrl() handlers. */
 	switch(cmd)
 		{
 	case ENGINE_CTRL_HAS_CTRL_FUNCTION:
 		return ctrl_exists;
 	case ENGINE_CTRL_GET_FIRST_CMD_TYPE:
 	case ENGINE_CTRL_GET_NEXT_CMD_TYPE:
 	case ENGINE_CTRL_GET_CMD_FROM_NAME:
 	case ENGINE_CTRL_GET_NAME_LEN_FROM_CMD:
 	case ENGINE_CTRL_GET_NAME_FROM_CMD:
 	case ENGINE_CTRL_GET_DESC_LEN_FROM_CMD:
 	case ENGINE_CTRL_GET_DESC_FROM_CMD:
 	case ENGINE_CTRL_GET_CMD_FLAGS:
 		if(ctrl_exists && !(e->flags & ENGINE_FLAGS_MANUAL_CMD_CTRL))
 			return int_ctrl_helper(e,cmd,i,p,f);
 		if(!ctrl_exists)
 			{
 			ENGINEerr(ENGINE_F_ENGINE_CTRL,ENGINE_R_NO_CONTROL_FUNCTION);
 			/* For these cmd-related functions, failure is indicated
 			 * by a -1 return value (because 0 is used as a valid
 			 * return in some places). */
 			return -1;
 			}
 	default:
 		break;
 		}
 	/* Anything else requires a ctrl() handler to exist. */
 	if(!ctrl_exists)
 		{
 		ENGINEerr(ENGINE_F_ENGINE_CTRL,ENGINE_R_NO_CONTROL_FUNCTION);
 		return 0;
 		}
 	return e->ctrl(e, cmd, i, p, f);
 	}

 int ENGINE_cmd_is_executable(ENGINE *e, int cmd)
 	{
 	int flags;
 	if((flags = ENGINE_ctrl(e, ENGINE_CTRL_GET_CMD_FLAGS, cmd, NULL, NULL)) < 0)
 		{
 		ENGINEerr(ENGINE_F_ENGINE_CMD_IS_EXECUTABLE,
 			ENGINE_R_INVALID_CMD_NUMBER);
 		return 0;
 		}
 	if(!(flags & ENGINE_CMD_FLAG_NO_INPUT) &&
 			!(flags & ENGINE_CMD_FLAG_NUMERIC) &&
 			!(flags & ENGINE_CMD_FLAG_STRING))
 		return 0;
 	return 1;
 	}

 int ENGINE_ctrl_cmd(ENGINE *e, const char *cmd_name,
         long i, void *p, void (*f)(void), int cmd_optional)
         {
 	int num;

 	if((e == NULL) || (cmd_name == NULL))
 		{
 		ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD,
 			ERR_R_PASSED_NULL_PARAMETER);
 		return 0;
 		}
 	if((e->ctrl == NULL) || ((num = ENGINE_ctrl(e,
 					ENGINE_CTRL_GET_CMD_FROM_NAME,
 					0, (void *)cmd_name, NULL)) <= 0))
 		{
 		/* If the command didn't *have* to be supported, we fake
 		 * success. This allows certain settings to be specified for
 		 * multiple ENGINEs and only require a change of ENGINE id
 		 * (without having to selectively apply settings). Eg. changing
 		 * from a hardware device back to the regular software ENGINE
 		 * without editing the config file, etc. */
 		if(cmd_optional)
 			{
 			ERR_clear_error();
 			return 1;
 			}
 		ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD,
 			ENGINE_R_INVALID_CMD_NAME);
 		return 0;
 		}
 	/* Force the result of the control command to 0 or 1, for the reasons
 	 * mentioned before. */
         if (ENGINE_ctrl(e, num, i, p, f))
                 return 1;
         return 0;
         }

 int ENGINE_ctrl_cmd_string(ENGINE *e, const char *cmd_name, const char *arg,
 				int cmd_optional)
 	{
 	int num, flags;
 	long l;
 	char *ptr;
 	if((e == NULL) || (cmd_name == NULL))
 		{
 		ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING,
 			ERR_R_PASSED_NULL_PARAMETER);
 		return 0;
 		}
 	if((e->ctrl == NULL) || ((num = ENGINE_ctrl(e,
 					ENGINE_CTRL_GET_CMD_FROM_NAME,
 					0, (void *)cmd_name, NULL)) <= 0))
 		{
 		/* If the command didn't *have* to be supported, we fake
 		 * success. This allows certain settings to be specified for
 		 * multiple ENGINEs and only require a change of ENGINE id
 		 * (without having to selectively apply settings). Eg. changing
 		 * from a hardware device back to the regular software ENGINE
 		 * without editing the config file, etc. */
 		if(cmd_optional)
 			{
 			ERR_clear_error();
 			return 1;
 			}
 		ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING,
 			ENGINE_R_INVALID_CMD_NAME);
 		return 0;
 		}
 	if(!ENGINE_cmd_is_executable(e, num))
 		{
 		ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING,
 			ENGINE_R_CMD_NOT_EXECUTABLE);
 		return 0;
 		}
 	if((flags = ENGINE_ctrl(e, ENGINE_CTRL_GET_CMD_FLAGS, num, NULL, NULL)) < 0)
 		{
 		/* Shouldn't happen, given that ENGINE_cmd_is_executable()
 		 * returned success. */
 		ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING,
 			ENGINE_R_INTERNAL_LIST_ERROR);
 		return 0;
 		}
 	/* If the command takes no input, there must be no input. And vice
 	 * versa. */
 	if(flags & ENGINE_CMD_FLAG_NO_INPUT)
 		{
 		if(arg != NULL)
 			{
 			ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING,
 				ENGINE_R_COMMAND_TAKES_NO_INPUT);
 			return 0;
 			}
 		/* We deliberately force the result of ENGINE_ctrl() to 0 or 1
 		 * rather than returning it as "return data". This is to ensure
 		 * usage of these commands is consistent across applications and
 		 * that certain applications don't understand it one way, and
 		 * others another. */
 		if(ENGINE_ctrl(e, num, 0, (void *)arg, NULL))
 			return 1;
 		return 0;
 		}
 	/* So, we require input */
 	if(arg == NULL)
 		{
 		ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING,
 			ENGINE_R_COMMAND_TAKES_INPUT);
 		return 0;
 		}
 	/* If it takes string input, that's easy */
 	if(flags & ENGINE_CMD_FLAG_STRING)
 		{
 		/* Same explanation as above */
 		if(ENGINE_ctrl(e, num, 0, (void *)arg, NULL))
 			return 1;
 		return 0;
 		}
 	/* If it doesn't take numeric either, then it is unsupported for use in
 	 * a config-setting situation, which is what this function is for. This
 	 * should never happen though, because ENGINE_cmd_is_executable() was
 	 * used. */
 	if(!(flags & ENGINE_CMD_FLAG_NUMERIC))
 		{
 		ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING,
 			ENGINE_R_INTERNAL_LIST_ERROR);
 		return 0;
 		}
 	l = strtol(arg, &ptr, 10);
 	if((arg == ptr) || (*ptr != '\0'))
 		{
 		ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING,
 			ENGINE_R_ARGUMENT_IS_NOT_A_NUMBER);
 		return 0;
 		}
 	/* Force the result of the control command to 0 or 1, for the reasons
 	 * mentioned before. */
 	if(ENGINE_ctrl(e, num, l, NULL, NULL))
 		return 1;
 	return 0;
 	}
	/* crypto/engine/eng_ctrl.c */
	/* ====================================================================
	* 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"

	/* When querying a ENGINE-specific control command's 'description', this string
	* is used if the ENGINE_CMD_DEFN has cmd_desc set to NULL. */
	static const char *int_no_description = "";

	/* These internal functions handle 'CMD'-related control commands when the
	* ENGINE in question has asked us to take care of it (ie. the ENGINE did not
	* set the ENGINE_FLAGS_MANUAL_CMD_CTRL flag. */

	static int int_ctrl_cmd_is_null(const ENGINE_CMD_DEFN *defn)
	{
	if((defn->cmd_num == 0) \|\| (defn->cmd_name == NULL))
	return 1;
	return 0;
	}

	static int int_ctrl_cmd_by_name(const ENGINE_CMD_DEFN defn, const char s)
	{
	int idx = 0;
	while(!int_ctrl_cmd_is_null(defn) && (strcmp(defn->cmd_name, s) != 0))
	{
	idx++;
	defn++;
	}
	if(int_ctrl_cmd_is_null(defn))
	/* The given name wasn't found */
	return -1;
	return idx;
	}

	static int int_ctrl_cmd_by_num(const ENGINE_CMD_DEFN *defn, unsigned int num)
	{
	int idx = 0;
	/* NB: It is stipulated that 'cmd_defn' lists are ordered by cmd_num. So
	* our searches don't need to take any longer than necessary. */
	while(!int_ctrl_cmd_is_null(defn) && (defn->cmd_num < num))
	{
	idx++;
	defn++;
	}
	if(defn->cmd_num == num)
	return idx;
	/* The given cmd_num wasn't found */
	return -1;
	}

	static int int_ctrl_helper(ENGINE e, int cmd, long i, void p,
	void (*f)(void))
	{
	int idx;
	char s = (char )p;
	/* Take care of the easy one first (eg. it requires no searches) */
	if(cmd == ENGINE_CTRL_GET_FIRST_CMD_TYPE)
	{
	if((e->cmd_defns == NULL) \|\| int_ctrl_cmd_is_null(e->cmd_defns))
	return 0;
	return e->cmd_defns->cmd_num;
	}
	/* One or two commands require that "p" be a valid string buffer */
	if((cmd == ENGINE_CTRL_GET_CMD_FROM_NAME) \|\|
	(cmd == ENGINE_CTRL_GET_NAME_FROM_CMD) \|\|
	(cmd == ENGINE_CTRL_GET_DESC_FROM_CMD))
	{
	if(s == NULL)
	{
	ENGINEerr(ENGINE_F_INT_CTRL_HELPER,
	ERR_R_PASSED_NULL_PARAMETER);
	return -1;
	}
	}
	/* Now handle cmd_name -> cmd_num conversion */
	if(cmd == ENGINE_CTRL_GET_CMD_FROM_NAME)
	{
	if((e->cmd_defns == NULL) \|\| ((idx = int_ctrl_cmd_by_name(
	e->cmd_defns, s)) < 0))
	{
	ENGINEerr(ENGINE_F_INT_CTRL_HELPER,
	ENGINE_R_INVALID_CMD_NAME);
	return -1;
	}
	return e->cmd_defns[idx].cmd_num;
	}
	/* For the rest of the commands, the 'long' argument must specify a
	* valie command number - so we need to conduct a search. */
	if((e->cmd_defns == NULL) \|\| ((idx = int_ctrl_cmd_by_num(e->cmd_defns,
	(unsigned int)i)) < 0))
	{
	ENGINEerr(ENGINE_F_INT_CTRL_HELPER,
	ENGINE_R_INVALID_CMD_NUMBER);
	return -1;
	}
	/* Now the logic splits depending on command type */
	switch(cmd)
	{
	case ENGINE_CTRL_GET_NEXT_CMD_TYPE:
	idx++;
	if(int_ctrl_cmd_is_null(e->cmd_defns + idx))
	/* end-of-list */
	return 0;
	else
	return e->cmd_defns[idx].cmd_num;
	case ENGINE_CTRL_GET_NAME_LEN_FROM_CMD:
	return strlen(e->cmd_defns[idx].cmd_name);
	case ENGINE_CTRL_GET_NAME_FROM_CMD:
	return BIO_snprintf(s,strlen(e->cmd_defns[idx].cmd_name) + 1,
	"%s", e->cmd_defns[idx].cmd_name);
	case ENGINE_CTRL_GET_DESC_LEN_FROM_CMD:
	if(e->cmd_defns[idx].cmd_desc)
	return strlen(e->cmd_defns[idx].cmd_desc);
	return strlen(int_no_description);
	case ENGINE_CTRL_GET_DESC_FROM_CMD:
	if(e->cmd_defns[idx].cmd_desc)
	return BIO_snprintf(s,
	strlen(e->cmd_defns[idx].cmd_desc) + 1,
	"%s", e->cmd_defns[idx].cmd_desc);
	return BIO_snprintf(s, strlen(int_no_description) + 1,"%s",
	int_no_description);
	case ENGINE_CTRL_GET_CMD_FLAGS:
	return e->cmd_defns[idx].cmd_flags;
	}
	/* Shouldn't really be here ... */
	ENGINEerr(ENGINE_F_INT_CTRL_HELPER,ENGINE_R_INTERNAL_LIST_ERROR);
	return -1;
	}

	int ENGINE_ctrl(ENGINE e, int cmd, long i, void p, void (*f)(void))
	{
	int ctrl_exists, ref_exists;
	if(e == NULL)
	{
	ENGINEerr(ENGINE_F_ENGINE_CTRL,ERR_R_PASSED_NULL_PARAMETER);
	return 0;
	}
	CRYPTO_w_lock(CRYPTO_LOCK_ENGINE);
	ref_exists = ((e->struct_ref > 0) ? 1 : 0);
	CRYPTO_w_unlock(CRYPTO_LOCK_ENGINE);
	ctrl_exists = ((e->ctrl == NULL) ? 0 : 1);
	if(!ref_exists)
	{
	ENGINEerr(ENGINE_F_ENGINE_CTRL,ENGINE_R_NO_REFERENCE);
	return 0;
	}
	/* Intercept any "root-level" commands before trying to hand them on to
	* ctrl() handlers. */
	switch(cmd)
	{
	case ENGINE_CTRL_HAS_CTRL_FUNCTION:
	return ctrl_exists;
	case ENGINE_CTRL_GET_FIRST_CMD_TYPE:
	case ENGINE_CTRL_GET_NEXT_CMD_TYPE:
	case ENGINE_CTRL_GET_CMD_FROM_NAME:
	case ENGINE_CTRL_GET_NAME_LEN_FROM_CMD:
	case ENGINE_CTRL_GET_NAME_FROM_CMD:
	case ENGINE_CTRL_GET_DESC_LEN_FROM_CMD:
	case ENGINE_CTRL_GET_DESC_FROM_CMD:
	case ENGINE_CTRL_GET_CMD_FLAGS:
	if(ctrl_exists && !(e->flags & ENGINE_FLAGS_MANUAL_CMD_CTRL))
	return int_ctrl_helper(e,cmd,i,p,f);
	if(!ctrl_exists)
	{
	ENGINEerr(ENGINE_F_ENGINE_CTRL,ENGINE_R_NO_CONTROL_FUNCTION);
	/* For these cmd-related functions, failure is indicated
	* by a -1 return value (because 0 is used as a valid
	* return in some places). */
	return -1;
	}
	default:
	break;
	}
	/* Anything else requires a ctrl() handler to exist. */
	if(!ctrl_exists)
	{
	ENGINEerr(ENGINE_F_ENGINE_CTRL,ENGINE_R_NO_CONTROL_FUNCTION);
	return 0;
	}
	return e->ctrl(e, cmd, i, p, f);
	}

	int ENGINE_cmd_is_executable(ENGINE *e, int cmd)
	{
	int flags;
	if((flags = ENGINE_ctrl(e, ENGINE_CTRL_GET_CMD_FLAGS, cmd, NULL, NULL)) < 0)
	{
	ENGINEerr(ENGINE_F_ENGINE_CMD_IS_EXECUTABLE,
	ENGINE_R_INVALID_CMD_NUMBER);
	return 0;
	}
	if(!(flags & ENGINE_CMD_FLAG_NO_INPUT) &&
	!(flags & ENGINE_CMD_FLAG_NUMERIC) &&
	!(flags & ENGINE_CMD_FLAG_STRING))
	return 0;
	return 1;
	}

	int ENGINE_ctrl_cmd(ENGINE e, const char cmd_name,
	long i, void p, void (f)(void), int cmd_optional)
	{
	int num;

	if((e == NULL) \|\| (cmd_name == NULL))
	{
	ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD,
	ERR_R_PASSED_NULL_PARAMETER);
	return 0;
	}
	if((e->ctrl == NULL) \|\| ((num = ENGINE_ctrl(e,
	ENGINE_CTRL_GET_CMD_FROM_NAME,
	0, (void *)cmd_name, NULL)) <= 0))
	{
	/* If the command didn't have to be supported, we fake
	* success. This allows certain settings to be specified for
	* multiple ENGINEs and only require a change of ENGINE id
	* (without having to selectively apply settings). Eg. changing
	* from a hardware device back to the regular software ENGINE
	* without editing the config file, etc. */
	if(cmd_optional)
	{
	ERR_clear_error();
	return 1;
	}
	ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD,
	ENGINE_R_INVALID_CMD_NAME);
	return 0;
	}
	/* Force the result of the control command to 0 or 1, for the reasons
	* mentioned before. */
	if (ENGINE_ctrl(e, num, i, p, f))
	return 1;
	return 0;
	}

	int ENGINE_ctrl_cmd_string(ENGINE e, const char cmd_name, const char *arg,
	int cmd_optional)
	{
	int num, flags;
	long l;
	char *ptr;
	if((e == NULL) \|\| (cmd_name == NULL))
	{
	ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING,
	ERR_R_PASSED_NULL_PARAMETER);
	return 0;
	}
	if((e->ctrl == NULL) \|\| ((num = ENGINE_ctrl(e,
	ENGINE_CTRL_GET_CMD_FROM_NAME,
	0, (void *)cmd_name, NULL)) <= 0))
	{
	/* If the command didn't have to be supported, we fake
	* success. This allows certain settings to be specified for
	* multiple ENGINEs and only require a change of ENGINE id
	* (without having to selectively apply settings). Eg. changing
	* from a hardware device back to the regular software ENGINE
	* without editing the config file, etc. */
	if(cmd_optional)
	{
	ERR_clear_error();
	return 1;
	}
	ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING,
	ENGINE_R_INVALID_CMD_NAME);
	return 0;
	}
	if(!ENGINE_cmd_is_executable(e, num))
	{
	ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING,
	ENGINE_R_CMD_NOT_EXECUTABLE);
	return 0;
	}
	if((flags = ENGINE_ctrl(e, ENGINE_CTRL_GET_CMD_FLAGS, num, NULL, NULL)) < 0)
	{
	/* Shouldn't happen, given that ENGINE_cmd_is_executable()
	* returned success. */
	ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING,
	ENGINE_R_INTERNAL_LIST_ERROR);
	return 0;
	}
	/* If the command takes no input, there must be no input. And vice
	* versa. */
	if(flags & ENGINE_CMD_FLAG_NO_INPUT)
	{
	if(arg != NULL)
	{
	ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING,
	ENGINE_R_COMMAND_TAKES_NO_INPUT);
	return 0;
	}
	/* We deliberately force the result of ENGINE_ctrl() to 0 or 1
	* rather than returning it as "return data". This is to ensure
	* usage of these commands is consistent across applications and
	* that certain applications don't understand it one way, and
	* others another. */
	if(ENGINE_ctrl(e, num, 0, (void *)arg, NULL))
	return 1;
	return 0;
	}
	/* So, we require input */
	if(arg == NULL)
	{
	ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING,
	ENGINE_R_COMMAND_TAKES_INPUT);
	return 0;
	}
	/* If it takes string input, that's easy */
	if(flags & ENGINE_CMD_FLAG_STRING)
	{
	/* Same explanation as above */
	if(ENGINE_ctrl(e, num, 0, (void *)arg, NULL))
	return 1;
	return 0;
	}
	/* If it doesn't take numeric either, then it is unsupported for use in
	* a config-setting situation, which is what this function is for. This
	* should never happen though, because ENGINE_cmd_is_executable() was
	* used. */
	if(!(flags & ENGINE_CMD_FLAG_NUMERIC))
	{
	ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING,
	ENGINE_R_INTERNAL_LIST_ERROR);
	return 0;
	}
	l = strtol(arg, &ptr, 10);
	if((arg == ptr) \|\| (*ptr != '\0'))
	{
	ENGINEerr(ENGINE_F_ENGINE_CTRL_CMD_STRING,
	ENGINE_R_ARGUMENT_IS_NOT_A_NUMBER);
	return 0;
	}
	/* Force the result of the control command to 0 or 1, for the reasons
	* mentioned before. */
	if(ENGINE_ctrl(e, num, l, NULL, NULL))
	return 1;
	return 0;
	}