path: root/crypto/engine/engine.h

/* openssl/engine.h */
/* Written by Geoff Thorpe (geoff@geoffthorpe.net) for the OpenSSL
 * project 2000.
 */
/* ====================================================================
 * Copyright (c) 1999 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).
 *
 */

#ifndef HEADER_ENGINE_H
#define HEADER_ENGINE_H

#include <openssl/bn.h>
#ifndef OPENSSL_NO_RSA
#include <openssl/rsa.h>
#endif
#ifndef OPENSSL_NO_DSA
#include <openssl/dsa.h>
#endif
#ifndef OPENSSL_NO_DH
#include <openssl/dh.h>
#endif
#include <openssl/rand.h>
#include <openssl/evp.h>
#include <openssl/symhacks.h>

#ifdef  __cplusplus
extern "C" {
#endif

/* Fixups for missing algorithms */
#ifdef OPENSSL_NO_RSA
typedef void RSA_METHOD;
#endif
#ifdef OPENSSL_NO_DSA
typedef void DSA_METHOD;
#endif
#ifdef OPENSSL_NO_DH
typedef void DH_METHOD;
#endif

/* These flags are used to control combinations of algorithm (methods)
 * by bitwise "OR"ing. */
#define ENGINE_METHOD_RSA		(unsigned int)0x0001
#define ENGINE_METHOD_DSA		(unsigned int)0x0002
#define ENGINE_METHOD_DH		(unsigned int)0x0004
#define ENGINE_METHOD_RAND		(unsigned int)0x0008
#define ENGINE_METHOD_BN_MOD_EXP	(unsigned int)0x0010
#define ENGINE_METHOD_BN_MOD_EXP_CRT	(unsigned int)0x0020
/* Obvious all-or-nothing cases. */
#define ENGINE_METHOD_ALL		(unsigned int)0xFFFF
#define ENGINE_METHOD_NONE		(unsigned int)0x0000

/* ENGINE flags that can be set by ENGINE_set_flags(). */
/* #define ENGINE_FLAGS_MALLOCED	0x0001 */ /* Not used */

/* This flag is for ENGINEs that wish to handle the various 'CMD'-related
 * control commands on their own. Without this flag, ENGINE_ctrl() handles these
 * control commands on behalf of the ENGINE using their "cmd_defns" data. */
#define ENGINE_FLAGS_MANUAL_CMD_CTRL	(int)0x0002

/* ENGINEs can support their own command types, and these flags are used in
 * ENGINE_CTRL_GET_CMD_FLAGS to indicate to the caller what kind of input each
 * command expects. Currently only numeric and string input is supported. If a
 * control command supports none of the _NUMERIC, _STRING, or _NO_INPUT options,
 * then it is regarded as an "internal" control command - and not for use in
 * config setting situations. As such, they're not available to the
 * ENGINE_ctrl_cmd_string() function, only raw ENGINE_ctrl() access. Changes to
 * this list of 'command types' should be reflected carefully in
 * ENGINE_cmd_is_executable() and ENGINE_ctrl_cmd_string(). */

/* accepts a 'long' input value (3rd parameter to ENGINE_ctrl) */
#define ENGINE_CMD_FLAG_NUMERIC		(unsigned int)0x0001
/* accepts string input (cast from 'void*' to 'const char *', 4th parameter to
 * ENGINE_ctrl) */
#define ENGINE_CMD_FLAG_STRING		(unsigned int)0x0002
/* Indicates that the control command takes *no* input. Ie. the control command
 * is unparameterised. */
#define ENGINE_CMD_FLAG_NO_INPUT	(unsigned int)0x0004

/* NB: These 3 control commands are deprecated and should not be used. ENGINEs
 * relying on these commands should compile conditional support for
 * compatibility (eg. if these symbols are defined) but should also migrate the
 * same functionality to their own ENGINE-specific control functions that can be
 * "discovered" by calling applications. The fact these control commands
 * wouldn't be "executable" (ie. usable by text-based config) doesn't change the
 * fact that application code can find and use them without requiring per-ENGINE
 * hacking. */

/* These flags are used to tell the ctrl function what should be done.
 * All command numbers are shared between all engines, even if some don't
 * make sense to some engines.  In such a case, they do nothing but return
 * the error ENGINE_R_CTRL_COMMAND_NOT_IMPLEMENTED. */
#define ENGINE_CTRL_SET_LOGSTREAM		1
#define ENGINE_CTRL_SET_PASSWORD_CALLBACK	2
#define ENGINE_CTRL_HUP				3 /* Close and reinitialise any
						     handles/connections etc. */

/* These control commands allow an application to deal with an arbitrary engine
 * in a dynamic way. Warn: Negative return values indicate errors FOR THESE
 * COMMANDS because zero is used to indicate 'end-of-list'. Other commands,
 * including ENGINE-specific command types, return zero for an error.
 *
 * An ENGINE can choose to implement these ctrl functions, and can internally
 * manage things however it chooses - it does so by setting the
 * ENGINE_FLAGS_MANUAL_CMD_CTRL flag (using ENGINE_set_flags()). Otherwise the
 * ENGINE_ctrl() code handles this on the ENGINE's behalf using the cmd_defns
 * data (set using ENGINE_set_cmd_defns()). This means an ENGINE's ctrl()
 * handler need only implement its own commands - the above "meta" commands will
 * be taken care of. */

/* Returns non-zero if the supplied ENGINE has a ctrl() handler. If "not", then
 * all the remaining control commands will return failure, so it is worth
 * checking this first if the caller is trying to "discover" the engine's
 * capabilities and doesn't want errors generated unnecessarily. */
#define ENGINE_CTRL_HAS_CTRL_FUNCTION		10
/* Returns a positive command number for the first command supported by the
 * engine. Returns zero if no ctrl commands are supported. */
#define ENGINE_CTRL_GET_FIRST_CMD_TYPE		11
/* The 'long' argument specifies a command implemented by the engine, and the
 * return value is the next command supported, or zero if there are no more. */
#define ENGINE_CTRL_GET_NEXT_CMD_TYPE		12
/* The 'void*' argument is a command name (cast from 'const char *'), and the
 * return value is the command that corresponds to it. */
#define ENGINE_CTRL_GET_CMD_FROM_NAME		13
/* The next two allow a command to be converted into its corresponding string
 * form. In each case, the 'long' argument supplies the command. In the NAME_LEN
 * case, the return value is the length of the command name (not counting a
 * trailing EOL). In the NAME case, the 'void*' argument must be a string buffer
 * large enough, and it will be populated with the name of the command (WITH a
 * trailing EOL). */
#define ENGINE_CTRL_GET_NAME_LEN_FROM_CMD	14
#define ENGINE_CTRL_GET_NAME_FROM_CMD		15
/* The next two are similar but give a "short description" of a command. */
#define ENGINE_CTRL_GET_DESC_LEN_FROM_CMD	16
#define ENGINE_CTRL_GET_DESC_FROM_CMD		17
/* With this command, the return value is the OR'd combination of
 * ENGINE_CMD_FLAG_*** values that indicate what kind of input a given
 * engine-specific ctrl command expects. */
#define ENGINE_CTRL_GET_CMD_FLAGS		18

/* ENGINE implementations should start the numbering of their own control
 * commands from this value. (ie. ENGINE_CMD_BASE, ENGINE_CMD_BASE + 1, etc). */
#define ENGINE_CMD_BASE		200

/* NB: These 2 nCipher "chil" control commands are deprecated, and their
 * functionality is now available through ENGINE-specific control commands
 * (exposed through the above-mentioned 'CMD'-handling). Code using these 2
 * commands should be migrated to the more general command handling before these
 * are removed. */

/* Flags specific to the nCipher "chil" engine */
#define ENGINE_CTRL_CHIL_SET_FORKCHECK		100
	/* Depending on the value of the (long)i argument, this sets or
	 * unsets the SimpleForkCheck flag in the CHIL API to enable or
	 * disable checking and workarounds for applications that fork().
	 */
#define ENGINE_CTRL_CHIL_NO_LOCKING		101
	/* This prevents the initialisation function from providing mutex
	 * callbacks to the nCipher library. */

/* If an ENGINE supports its own specific control commands and wishes the
 * framework to handle the above 'ENGINE_CMD_***'-manipulation commands on its
 * behalf, it should supply a null-terminated array of ENGINE_CMD_DEFN entries
 * to ENGINE_set_cmd_defns(). It should also implement a ctrl() handler that
 * supports the stated commands (ie. the "cmd_num" entries as described by the
 * array). NB: The array must be ordered in increasing order of cmd_num.
 * "null-terminated" means that the last ENGINE_CMD_DEFN element has cmd_num set
 * to zero and/or cmd_name set to NULL. */
typedef struct ENGINE_CMD_DEFN_st
	{
	unsigned int cmd_num; /* The command number */
	const char *cmd_name; /* The command name itself */
	const char *cmd_desc; /* A short description of the command */
	unsigned int cmd_flags; /* The input the command expects */
	} ENGINE_CMD_DEFN;

/* As we're missing a BIGNUM_METHOD, we need a couple of locally
 * defined function types that engines can implement. */

/* mod_exp operation, calculates; r = a ^ p mod m
 * NB: ctx can be NULL, but if supplied, the implementation may use
 * it if it wishes. */
typedef int (*BN_MOD_EXP)(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
		const BIGNUM *m, BN_CTX *ctx);

/* private key operation for RSA, provided seperately in case other
 * RSA implementations wish to use it. */
typedef int (*BN_MOD_EXP_CRT)(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
		const BIGNUM *q, const BIGNUM *dmp1, const BIGNUM *dmq1,
		const BIGNUM *iqmp, BN_CTX *ctx);

/* The list of "engine" types is a static array of (const ENGINE*)
 * pointers (not dynamic because static is fine for now and we otherwise
 * have to hook an appropriate load/unload function in to initialise and
 * cleanup). */
struct engine_st;
typedef struct engine_st ENGINE;

/* Generic function pointer */
typedef int (*ENGINE_GEN_FUNC_PTR)();
/* Generic function pointer taking no arguments */
typedef int (*ENGINE_GEN_INT_FUNC_PTR)(ENGINE *);
/* Specific control function pointer */
typedef int (*ENGINE_CTRL_FUNC_PTR)(ENGINE *, int, long, void *, void (*f)());
/* Generic load_key function pointer */
typedef EVP_PKEY * (*ENGINE_LOAD_KEY_PTR)(ENGINE *, const char *, const char *);

/* STRUCTURE functions ... all of these functions deal with pointers to ENGINE
 * structures where the pointers have a "structural reference". This means that
 * their reference is to allowed access to the structure but it does not imply
 * that the structure is functional. To simply increment or decrement the
 * structural reference count, use ENGINE_by_id and ENGINE_free. NB: This is not
 * required when iterating using ENGINE_get_next as it will automatically
 * decrement the structural reference count of the "current" ENGINE and
 * increment the structural reference count of the ENGINE it returns (unless it
 * is NULL). */

/* Get the first/last "ENGINE" type available. */
ENGINE *ENGINE_get_first(void);
ENGINE *ENGINE_get_last(void);
/* Iterate to the next/previous "ENGINE" type (NULL = end of the list). */
ENGINE *ENGINE_get_next(ENGINE *e);
ENGINE *ENGINE_get_prev(ENGINE *e);
/* Add another "ENGINE" type into the array. */
int ENGINE_add(ENGINE *e);
/* Remove an existing "ENGINE" type from the array. */
int ENGINE_remove(ENGINE *e);
/* Retrieve an engine from the list by its unique "id" value. */
ENGINE *ENGINE_by_id(const char *id);
/* Add all the built-in engines.  By default, only the OpenSSL software
   engine is loaded */
void ENGINE_load_cswift(void);
void ENGINE_load_chil(void);
void ENGINE_load_atalla(void);
void ENGINE_load_nuron(void);
void ENGINE_load_ubsec(void);
void ENGINE_load_builtin_engines(void);

/* Send parametrised control commands to the engine. The possibilities to send
 * down an integer, a pointer to data or a function pointer are provided. Any of
 * the parameters may or may not be NULL, depending on the command number. In
 * actuality, this function only requires a structural (rather than functional)
 * reference to an engine, but many control commands may require the engine be
 * functional. The caller should be aware of trying commands that require an
 * operational ENGINE, and only use functional references in such situations. */
int ENGINE_ctrl(ENGINE *e, int cmd, long i, void *p, void (*f)());

/* This function tests if an ENGINE-specific command is usable as a "setting".
 * Eg. in an application's config file that gets processed through
 * ENGINE_ctrl_cmd_string(). If this returns zero, it is not available to
 * ENGINE_ctrl_cmd_string(), only ENGINE_ctrl(). */
int ENGINE_cmd_is_executable(ENGINE *e, int cmd);

/* This function passes a command-name and argument to an ENGINE. The cmd_name
 * is converted to a command number and the control command is called using
 * 'arg' as an argument (unless the ENGINE doesn't support such a command, in
 * which case no control command is called). The command is checked for input
 * flags, and if necessary the argument will be converted to a numeric value. If
 * cmd_optional is non-zero, then if the ENGINE doesn't support the given
 * cmd_name the return value will be success anyway. This function is intended
 * for applications to use so that users (or config files) can supply
 * engine-specific config data to the ENGINE at run-time to control behaviour of
 * specific engines. As such, it shouldn't be used for calling ENGINE_ctrl()
 * functions that return data, deal with binary data, or that are otherwise
 * supposed to be used directly through ENGINE_ctrl() in application code. Any
 * "return" data from an ENGINE_ctrl() operation in this function will be lost -
 * the return value is interpreted as failure if the return value is zero,
 * success otherwise, and this function returns a boolean value as a result. In
 * other words, vendors of 'ENGINE'-enabled devices should write ENGINE
 * implementations with parameterisations that work in this scheme, so that
 * compliant ENGINE-based applications can work consistently with the same
 * configuration for the same ENGINE-enabled devices, across applications. */
int ENGINE_ctrl_cmd_string(ENGINE *e, const char *cmd_name, const char *arg,
				int cmd_optional);

/* These functions are useful for manufacturing new ENGINE structures. They
 * don't address reference counting at all - one uses them to populate an ENGINE
 * structure with personalised implementations of things prior to using it
 * directly or adding it to the builtin ENGINE list in OpenSSL. These are also
 * here so that the ENGINE structure doesn't have to be exposed and break binary
 * compatibility! */
ENGINE *ENGINE_new(void);
int ENGINE_free(ENGINE *e);
int ENGINE_set_id(ENGINE *e, const char *id);
int ENGINE_set_name(ENGINE *e, const char *name);
int ENGINE_set_RSA(ENGINE *e, const RSA_METHOD *rsa_meth);
int ENGINE_set_DSA(ENGINE *e, const DSA_METHOD *