/* openssl/engine.h */
/* Written by Geoff Thorpe (geoff@geoffthorpe.net) for the OpenSSL
 * project 2000.
 */
/* ====================================================================
 * Copyright (c) 1999-2004 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).
 *
 */
/* ====================================================================
 * Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED.
 * ECDH support in OpenSSL originally developed by
 * SUN MICROSYSTEMS, INC., and contributed to the OpenSSL project.
 */

module deimos.openssl.engine;

import deimos.openssl._d_util;

public import deimos.openssl.opensslconf;

version (OPENSSL_NO_ENGINE) {
  static assert(false, "ENGINE is disabled.");
}

version(OPENSSL_NO_DEPRECATED) {} else {
public import deimos.openssl.bn;
version(OPENSSL_NO_RSA) {} else {
public import deimos.openssl.rsa;
}
version(OPENSSL_NO_DSA) {} else {
public import deimos.openssl.dsa;
}
version(OPENSSL_NO_DH) {} else {
public import deimos.openssl.dh;
}
version(OPENSSL_NO_ECDH) {} else {
public import deimos.openssl.ecdh;
}
version(OPENSSL_NO_ECDSA) {} else {
public import deimos.openssl.ecdsa;
}
public import deimos.openssl.rand;
public import deimos.openssl.ui;
public import deimos.openssl.err;
}

public import deimos.openssl.ossl_typ;
public import deimos.openssl.symhacks;

public import deimos.openssl.x509;

extern (C):
nothrow:

/* These flags are used to control combinations of algorithm (methods)
 * by bitwise "OR"ing. */
enum ENGINE_METHOD_RSA = 0x0001;
enum ENGINE_METHOD_DSA = 0x0002;
enum ENGINE_METHOD_DH = 0x0004;
enum ENGINE_METHOD_RAND = 0x0008;
enum ENGINE_METHOD_ECDH = 0x0010;
enum ENGINE_METHOD_ECDSA = 0x0020;
enum ENGINE_METHOD_CIPHERS = 0x0040;
enum ENGINE_METHOD_DIGESTS = 0x0080;
enum ENGINE_METHOD_STORE = 0x0100;
enum ENGINE_METHOD_PKEY_METHS = 0x0200;
enum ENGINE_METHOD_PKEY_ASN1_METHS = 0x0400;
/* Obvious all-or-nothing cases. */
enum ENGINE_METHOD_ALL = 0xFFFF;
enum ENGINE_METHOD_NONE = 0x0000;

/* This(ese) flag(s) controls behaviour of the ENGINE_TABLE mechanism used
 * internally to control registration of ENGINE implementations, and can be set
 * by ENGINE_set_table_flags(). The "NOINIT" flag prevents attempts to
 * initialise registered ENGINEs if they are not already initialised. */
enum ENGINE_TABLE_FLAG_NOINIT = 0x0001;

/* ENGINE flags that can be set by ENGINE_set_flags(). */
/* enum 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. */
enum ENGINE_FLAGS_MANUAL_CMD_CTRL = 0x0002;

/* This flag is for ENGINEs who return new duplicate structures when found via
 * "ENGINE_by_id()". When an ENGINE must store state (eg. if ENGINE_ctrl()
 * commands are called in sequence as part of some stateful process like
 * key-generation setup and execution), it can set this flag - then each attempt
 * to obtain the ENGINE will result in it being copied into a new structure.
 * Normally, ENGINEs don't declare this flag so ENGINE_by_id() just increments
 * the existing ENGINE's structural reference count. */
enum ENGINE_FLAGS_BY_ID_COPY = 0x0004;

/* 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) */
enum ENGINE_CMD_FLAG_NUMERIC = 0x0001;
/* accepts string input (cast from 'void*' to 'const(char)* ', 4th parameter to
 * ENGINE_ctrl) */
enum ENGINE_CMD_FLAG_STRING = 0x0002;
/* Indicates that the control command takes* no* input. Ie. the control command
 * is unparameterised. */
enum ENGINE_CMD_FLAG_NO_INPUT = 0x0004;
/* Indicates that the control command is internal. This control command won't
 * be shown in any output, and is only usable through the ENGINE_ctrl_cmd()
 * function. */
enum ENGINE_CMD_FLAG_INTERNAL = 0x0008;

/* 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. */
enum ENGINE_CTRL_SET_LOGSTREAM = 1;
enum ENGINE_CTRL_SET_PASSWORD_CALLBACK = 2;
enum ENGINE_CTRL_HUP = 3; /* Close and reinitialise any
						     handles/connections etc. */
enum ENGINE_CTRL_SET_USER_INTERFACE = 4; /* Alternative to callback */
enum ENGINE_CTRL_SET_CALLBACK_DATA = 5; /* User-specific data, used
						     when calling the password
						     callback and the user
						     interface */
enum ENGINE_CTRL_LOAD_CONFIGURATION = 6; /* Load a configuration, given
						     a string that represents a
						     file name or so */
enum ENGINE_CTRL_LOAD_SECTION = 7; /* Load data from a given
						     section in the already loaded
						     configuration */

/* 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. */
enum 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. */
enum 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. */
enum 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. */
enum 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). */
enum ENGINE_CTRL_GET_NAME_LEN_FROM_CMD = 14;
enum ENGINE_CTRL_GET_NAME_FROM_CMD = 15;
/* The next two are similar but give a "short description" of a command. */
enum ENGINE_CTRL_GET_DESC_LEN_FROM_CMD = 16;
enum 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. */
enum 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). */
enum 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 */
enum ENGINE_CTRL_CHIL_SET_FORKCHECK = 100;
	/* Depending on the value of the (c_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().
	 */
enum 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. */
struct ENGINE_CMD_DEFN_st {
	uint cmd_num; /* The command number */
	const(char)* cmd_name; /* The command name itself */
	const(char)* cmd_desc; /* A short description of the command */
	uint cmd_flags; /* The input the command expects */
	}
alias ENGINE_CMD_DEFN_st ENGINE_CMD_DEFN;

/* Generic function pointer */
alias ExternC!(int function()) ENGINE_GEN_FUNC_PTR;
/* Generic function pointer taking no arguments */
alias ExternC!(int function(ENGINE*)) ENGINE_GEN_INT_FUNC_PTR;
/* Specific control function pointer */
alias ExternC!(int function(ENGINE*, int, c_long, void*, ExternC!(void function()) f)) ENGINE_CTRL_FUNC_PTR;
/* Generic load_key function pointer */
alias ExternC!(EVP_PKEY*function(ENGINE*, const(char)*,
	UI_METHOD* ui_method, void* callback_data)) ENGINE_LOAD_KEY_PTR;
alias ExternC!(int function(ENGINE*, SSL* ssl,
	STACK_OF!(X509_NAME) *ca_dn, X509** pcert, EVP_PKEY** pkey,
	STACK_OF!(X509) **pother, UI_METHOD* ui_method, void* callback_data)) ENGINE_SSL_CLIENT_CERT_PTR;
/* These callback types are for an ENGINE's handler for cipher and digest logic.
 * These handlers have these prototypes;
 *  int foo(ENGINE* e, const(EVP_CIPHER)** cipher, const(int)** nids, int nid);
 *  int foo(ENGINE* e, const(EVP_MD)** digest, const(int)** nids, int nid);
 * Looking at how to implement these handlers in the case of cipher support, if
 * the framework wants the EVP_CIPHER for 'nid', it will call;
 *  foo(e, &p_evp_cipher, NULL, nid);    (return zero for failure)
 * If the framework wants a list of supported 'nid's, it will call;
 *  foo(e, NULL, &p_nids, 0); (returns number of 'nids' or -1 for error)
 */
/* Returns to a pointer to the array of supported cipher 'nid's. If the second
 * parameter is non-NULL it is set to the size of the returned array. */
alias ExternC!(int function(ENGINE*, const(EVP_CIPHER)**, const(int)**, int)) ENGINE_CIPHERS_PTR;
alias ExternC!(int function(ENGINE*, const(EVP_MD)**, const(int)**, int)) ENGINE_DIGESTS_PTR;
alias ExternC!(int function(ENGINE*, EVP_PKEY_METHOD**, const(int)**, int)) ENGINE_PKEY_METHS_PTR;
alias ExternC!(int function(ENGINE*, EVP_PKEY_ASN1_METHOD**, const(int)**, int)) ENGINE_PKEY_ASN1_METHS_PTR;
/* 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();
ENGINE* ENGINE_get_last();
/* 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. */
void ENGINE_load_openssl();
void ENGINE_load_dynamic();
version(OPENSSL_NO_STATIC_ENGINE) {} else {
void ENGINE_load_4758cca();
void ENGINE_load_aep();
void ENGINE_load_atalla();
void ENGINE_load_chil();
void ENGINE_load_cswift();
void ENGINE_load_nuron();
void ENGINE_load_sureware();
void ENGINE_load_ubsec();
void ENGINE_load_padlock();
void ENGINE_load_capi();
version(OPENSSL_NO_GMP) {} else {
void ENGINE_load_gmp();
}
version(OPENSSL_NO_GOST) {} else {
void ENGINE_load_gost();
}
}
void ENGINE_load_cryptodev();
void ENGINE_load_builtin_engines();

/* Get and set global flags (ENGINE_TABLE_FLAG_***) for the implementation
 * "registry" handling. */
uint ENGINE_get_table_flags();
void ENGINE_set_table_flags(uint flags);

/* Manage registration of ENGINEs per "table". For each type, there are 3
 * functions;
 *  ENGINE_register_***(e) - registers the implementation from 'e' (if it has one)
 *  ENGINE_unregister_***(e) - unregister the implementation from 'e'
 *  ENGINE_register_all_***() - call ENGINE_register_***() for each 'e' in the list
 * Cleanup is automatically registered from each table when required, so
 * ENGINE_cleanup() will reverse any "register" operations. */

int ENGINE_register_RSA(ENGINE* e);
void ENGINE_unregister_RSA(ENGINE* e);
void ENGINE_register_all_RSA();

int ENGINE_register_DSA(ENGINE* e);
void ENGINE_unregister_DSA(ENGINE* e);
void ENGINE_register_all_DSA();

int ENGINE_register_ECDH(ENGINE* e);
void ENGINE_unregister_ECDH(ENGINE* e);
void ENGINE_register_all_ECDH();

int ENGINE_register_ECDSA(ENGINE* e);
void ENGINE_unregister_ECDSA(ENGINE* e);
void ENGINE_register_all_ECDSA();

int ENGINE_register_DH(ENGINE* e);
void ENGINE_unregister_DH(ENGINE* e);
void ENGINE_register_all_DH();

int ENGINE_register_RAND(ENGINE* e);
void ENGINE_unregister_RAND(ENGINE* e);
void ENGINE_register_all_RAND();

int ENGINE_register_STORE(ENGINE* e);
void ENGINE_unregister_STORE(ENGINE* e);
void ENGINE_register_all_STORE();

int ENGINE_register_ciphers(ENGINE* e);
void ENGINE_unregister_ciphers(ENGINE* e);
void ENGINE_register_all_ciphers();

int ENGINE_register_digests(ENGINE* e);
void ENGINE_unregister_digests(ENGINE* e);
void ENGINE_register_all_digests();

int ENGINE_register_pkey_meths(ENGINE* e);
void ENGINE_unregister_pkey_meths(ENGINE* e);
void ENGINE_register_all_pkey_meths();

int ENGINE_register_pkey_asn1_meths(ENGINE* e);
void ENGINE_unregister_pkey_asn1_meths(ENGINE* e);
void ENGINE_register_all_pkey_asn1_meths();

/* These functions register all support from the above categories. Note, use of
 * these functions can result in static linkage of code your application may not
 * need. If you only need a subset of functionality, consider using more
 * selective initialisation. */
int ENGINE_register_complete(ENGINE* e);
int ENGINE_register_all_complete();

/* 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, c_long i, void* p, ExternC!(void function()) 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 works like ENGINE_ctrl() with the exception of taking a
 * command name instead of a command number, and can handle optional commands.
 * See the comment on ENGINE_ctrl_cmd_string() for an explanation on how to
 * use the cmd_name and cmd_optional. */
int ENGINE_ctrl_cmd(ENGINE* e, const(char)* cmd_name,
        c_long i, void* p, ExternC!(void function()) f, int cmd_optional);

/* 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();
int ENGINE_free(ENGINE* e);
int ENGINE_up_ref(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)* dsa_meth);
int ENGINE_set_ECDH(ENGINE* e, const(ECDH_METHOD)* ecdh_meth);
int ENGINE_set_ECDSA(ENGINE* e, const(ECDSA_METHOD)* ecdsa_meth);
int ENGINE_set_DH(ENGINE* e, const(DH_METHOD)* dh_meth);
int ENGINE_set_RAND(ENGINE* e, const(RAND_METHOD)* rand_meth);
int ENGINE_set_STORE(ENGINE* e, const(STORE_METHOD)* store_meth);
int ENGINE_set_destroy_function(ENGINE* e, ENGINE_GEN_INT_FUNC_PTR destroy_f);
int ENGINE_set_init_function(ENGINE* e, ENGINE_GEN_INT_FUNC_PTR init_f);
int ENGINE_set_finish_function(ENGINE* e, ENGINE_GEN_INT_FUNC_PTR finish_f);
int ENGINE_set_ctrl_function(ENGINE* e, ENGINE_CTRL_FUNC_PTR ctrl_f);
int ENGINE_set_load_privkey_function(ENGINE* e, ENGINE_LOAD_KEY_PTR loadpriv_f);
int ENGINE_set_load_pubkey_function(ENGINE* e, ENGINE_LOAD_KEY_PTR loadpub_f);
int ENGINE_set_load_ssl_client_cert_function(ENGINE* e,
				ENGINE_SSL_CLIENT_CERT_PTR loadssl_f);
int ENGINE_set_ciphers(ENGINE* e, ENGINE_CIPHERS_PTR f);
int ENGINE_set_digests(ENGINE* e, ENGINE_DIGESTS_PTR f);
int ENGINE_set_pkey_meths(ENGINE* e, ENGINE_PKEY_METHS_PTR f);
int ENGINE_set_pkey_asn1_meths(ENGINE* e, ENGINE_PKEY_ASN1_METHS_PTR f);
int ENGINE_set_flags(ENGINE* e, int flags);
int ENGINE_set_cmd_defns(ENGINE* e, const(ENGINE_CMD_DEFN)* defns);
/* These functions allow control over any per-structure ENGINE data. */
int ENGINE_get_ex_new_index(c_long argl, void* argp, CRYPTO_EX_new* new_func,
		CRYPTO_EX_dup* dup_func, CRYPTO_EX_free* free_func);
int ENGINE_set_ex_data(ENGINE* e, int idx, void* arg);
void* ENGINE_get_ex_data(const(ENGINE)* e, int idx);

/* This function cleans up anything that needs it. Eg. the ENGINE_add() function
 * automatically ensures the list cleanup function is registered to be called
 * from ENGINE_cleanup(). Similarly, all ENGINE_register_*** functions ensure
 * ENGINE_cleanup() will clean up after them. */
void ENGINE_cleanup();

/* These return values from within the ENGINE structure. These can be useful
 * with functional references as well as structural references - it depends
 * which you obtained. Using the result for functional purposes if you only
 * obtained a structural reference may be problematic! */
const(char)* ENGINE_get_id(const(ENGINE)* e);
const(char)* ENGINE_get_name(const(ENGINE)* e);
const(RSA_METHOD)* ENGINE_get_RSA(const(ENGINE)* e);
const(DSA_METHOD)* ENGINE_get_DSA(const(ENGINE)* e);
const(ECDH_METHOD)* ENGINE_get_ECDH(const(ENGINE)* e);
const(ECDSA_METHOD)* ENGINE_get_ECDSA(const(ENGINE)* e);
const(DH_METHOD)* ENGINE_get_DH(const(ENGINE)* e);
const(RAND_METHOD)* ENGINE_get_RAND(const(ENGINE)* e);
const(STORE_METHOD)* ENGINE_get_STORE(const(ENGINE)* e);
ENGINE_GEN_INT_FUNC_PTR ENGINE_get_destroy_function(const(ENGINE)* e);
ENGINE_GEN_INT_FUNC_PTR ENGINE_get_init_function(const(ENGINE)* e);
ENGINE_GEN_INT_FUNC_PTR ENGINE_get_finish_function(const(ENGINE)* e);
ENGINE_CTRL_FUNC_PTR ENGINE_get_ctrl_function(const(ENGINE)* e);
ENGINE_LOAD_KEY_PTR ENGINE_get_load_privkey_function(const(ENGINE)* e);
ENGINE_LOAD_KEY_PTR ENGINE_get_load_pubkey_function(const(ENGINE)* e);
ENGINE_SSL_CLIENT_CERT_PTR ENGINE_get_ssl_client_cert_function(const(ENGINE)* e);
ENGINE_CIPHERS_PTR ENGINE_get_ciphers(const(ENGINE)* e);
ENGINE_DIGESTS_PTR ENGINE_get_digests(const(ENGINE)* e);
ENGINE_PKEY_METHS_PTR ENGINE_get_pkey_meths(const(ENGINE)* e);
ENGINE_PKEY_ASN1_METHS_PTR ENGINE_get_pkey_asn1_meths(const(ENGINE)* e);
const(EVP_CIPHER)* ENGINE_get_cipher(ENGINE* e, int nid);
const(EVP_MD)* ENGINE_get_digest(ENGINE* e, int nid);
const(EVP_PKEY_METHOD)* ENGINE_get_pkey_meth(ENGINE* e, int nid);
const(EVP_PKEY_ASN1_METHOD)* ENGINE_get_pkey_asn1_meth(ENGINE* e, int nid);
const(EVP_PKEY_ASN1_METHOD)* ENGINE_get_pkey_asn1_meth_str(ENGINE* e,
					const(char)* str, int len);
const(EVP_PKEY_ASN1_METHOD)* ENGINE_pkey_asn1_find_str(ENGINE** pe,
					const(char)* str, int len);
const(ENGINE_CMD_DEFN)* ENGINE_get_cmd_defns(const(ENGINE)* e);
int ENGINE_get_flags(const(ENGINE)* e);

/* FUNCTIONAL functions. These functions deal with ENGINE structures
 * that have (or will) be initialised for use. Broadly speaking, the
 * structural functions are useful for iterating the list of available
 * engine types, creating new engine types, and other "list" operations.
 * These functions actually deal with ENGINEs that are to be used. As
 * such these functions can fail (if applicable) when particular
 * engines are unavailable - eg. if a hardware accelerator is not
 * attached or not functioning correctly. Each ENGINE has 2 reference
 * counts; structural and functional. Every time a functional reference
 * is obtained or released, a corresponding structural reference is
 * automatically obtained or released too. */

/* Initialise a engine type for use (or up its reference count if it's
 * already in use). This will fail if the engine is not currently
 * operational and cannot initialise. */
int ENGINE_init(ENGINE* e);
/* Free a functional reference to a engine type. This does not require
 * a corresponding call to ENGINE_free as it also releases a structural
 * reference. */
int ENGINE_finish(ENGINE* e);

/* The following functions handle keys that are stored in some secondary
 * location, handled by the engine.  The storage may be on a card or
 * whatever. */
EVP_PKEY* ENGINE_load_private_key(ENGINE* e, const(char)* key_id,
	UI_METHOD* ui_method, void* callback_data);
EVP_PKEY* ENGINE_load_public_key(ENGINE* e, const(char)* key_id,
	UI_METHOD* ui_method, void* callback_data);
int ENGINE_load_ssl_client_cert(ENGINE* e, SSL* s,
	STACK_OF!(X509_NAME) *ca_dn, X509** pcert, EVP_PKEY** ppkey,
	STACK_OF!(X509) **pother,
	UI_METHOD* ui_method, void* callback_data);

/* This returns a pointer for the current ENGINE structure that
 * is (by default) performing any RSA operations. The value returned
 * is an incremented reference, so it should be free'd (ENGINE_finish)
 * before it is discarded. */
ENGINE* ENGINE_get_default_RSA();
/* Same for the other "methods" */
ENGINE* ENGINE_get_default_DSA();
ENGINE* ENGINE_get_default_ECDH();
ENGINE* ENGINE_get_default_ECDSA();
ENGINE* ENGINE_get_default_DH();
ENGINE* ENGINE_get_default_RAND();
/* These functions can be used to get a functional reference to perform
 * ciphering or digesting corresponding to "nid". */
ENGINE* ENGINE_get_cipher_engine(int nid);
ENGINE* ENGINE_get_digest_engine(int nid);
ENGINE* ENGINE_get_pkey_meth_engine(int nid);
ENGINE* ENGINE_get_pkey_asn1_meth_engine(int nid);

/* This sets a new default ENGINE structure for performing RSA
 * operations. If the result is non-zero (success) then the ENGINE
 * structure will have had its reference count up'd so the caller
 * should still free their own reference 'e'. */
int ENGINE_set_default_RSA(ENGINE* e);
int ENGINE_set_default_string(ENGINE* e, const(char)* def_list);
/* Same for the other "methods" */
int ENGINE_set_default_DSA(ENGINE* e);
int ENGINE_set_default_ECDH(ENGINE* e);
int ENGINE_set_default_ECDSA(ENGINE* e);
int ENGINE_set_default_DH(ENGINE* e);
int ENGINE_set_default_RAND(ENGINE* e);
int ENGINE_set_default_ciphers(ENGINE* e);
int ENGINE_set_default_digests(ENGINE* e);
int ENGINE_set_default_pkey_meths(ENGINE* e);
int ENGINE_set_default_pkey_asn1_meths(ENGINE* e);

/* The combination "set" - the flags are bitwise "OR"d from the
 * ENGINE_METHOD_*** defines above. As with the "ENGINE_register_complete()"
 * function, this function can result in unnecessary static linkage. If your
 * application requires only specific functionality, consider using more
 * selective functions. */
int ENGINE_set_default(ENGINE* e, uint flags);

void ENGINE_add_conf_module();

/* Deprecated functions ... */
/* int ENGINE_clear_defaults(); */

/**************************/
/* DYNAMIC ENGINE SUPPORT */
/**************************/

/* Binary/behaviour compatibility levels */
enum OSSL_DYNAMIC_VERSION = 0x00020000;
/* Binary versions older than this are too old for us (whether we're a loader or
 * a loadee) */
enum OSSL_DYNAMIC_OLDEST = 0x00020000;

/* When compiling an ENGINE entirely as an external shared library, loadable by
 * the "dynamic" ENGINE, these types are needed. The 'dynamic_fns' structure
 * type provides the calling application's (or library's) error functionality
 * and memory management function pointers to the loaded library. These should
 * be used/set in the loaded library code so that the loading application's
 * 'state' will be used/changed in all operations. The 'static_state' pointer
 * allows the loaded library to know if it shares the same static data as the
 * calling application (or library), and thus whether these callbacks need to be
 * set or not. */
alias ExternC!(void*function(size_t)) dyn_MEM_malloc_cb;
alias ExternC!(void*function(void*, size_t)) dyn_MEM_realloc_cb;
alias ExternC!(void function(void*)) dyn_MEM_free_cb;
struct st_dynamic_MEM_fns {
	dyn_MEM_malloc_cb			malloc_cb;
	dyn_MEM_realloc_cb			realloc_cb;
	dyn_MEM_free_cb				free_cb;
	}
alias st_dynamic_MEM_fns dynamic_MEM_fns;
/* FIXME: Perhaps the memory and locking code (crypto.h) should declare and use
 * these types so we (and any other dependant code) can simplify a bit?? */
alias ExternC!(void function(int,int,const(char)*,int)) dyn_lock_locking_cb;
alias ExternC!(int function(int*,int,int,const(char)*,int)) dyn_lock_add_lock_cb;
alias ExternC!(CRYPTO_dynlock_value*function(
						const(char)*,int)) dyn_dynlock_create_cb;
alias ExternC!(void function(int,CRYPTO_dynlock_value*,
						const(char)*,int)) dyn_dynlock_lock_cb;
alias ExternC!(void function(CRYPTO_dynlock_value*,
						const(char)*,int)) dyn_dynlock_destroy_cb;
struct st_dynamic_LOCK_fns {
	dyn_lock_locking_cb			lock_locking_cb;
	dyn_lock_add_lock_cb			lock_add_lock_cb;
	dyn_dynlock_create_cb			dynlock_create_cb;
	dyn_dynlock_lock_cb			dynlock_lock_cb;
	dyn_dynlock_destroy_cb			dynlock_destroy_cb;
	}
alias st_dynamic_LOCK_fns dynamic_LOCK_fns;
/* The top-level structure */
struct st_dynamic_fns {
	void* static_state;
	const(ERR_FNS)* err_fns;
	const(CRYPTO_EX_DATA_IMPL)* ex_data_fns;
	dynamic_MEM_fns				mem_fns;
	dynamic_LOCK_fns			lock_fns;
	}
alias st_dynamic_fns dynamic_fns;

/* The version checking function should be of this prototype. NB: The
 * ossl_version value passed in is the OSSL_DYNAMIC_VERSION of the loading code.
 * If this function returns zero, it indicates a (potential) version
 * incompatibility and the loaded library doesn't believe it can proceed.
 * Otherwise, the returned value is the (latest) version supported by the
 * loading library. The loader may still decide that the loaded code's version
 * is unsatisfactory and could veto the load. The function is expected to
 * be implemented with the symbol name "v_check", and a default implementation
 * can be fully instantiated with IMPLEMENT_DYNAMIC_CHECK_FN(). */
alias ExternC!(c_ulong function(c_ulong ossl_version)) dynamic_v_check_fn;
template IMPLEMENT_DYNAMIC_CHECK_FN() {
	enum IMPLEMENT_DYNAMIC_CHECK_FN = q{
	extern(C) c_ulong v_check(c_ulong v);
	extern(C) c_ulong v_check(c_ulong v) {
		if(v >= OSSL_DYNAMIC_OLDEST) return OSSL_DYNAMIC_VERSION;
		return 0; }
	};
}

/* This function is passed the ENGINE structure to initialise with its own
 * function and command settings. It should not adjust the structural or
 * functional reference counts. If this function returns zero, (a) the load will
 * be aborted, (b) the previous ENGINE state will be memcpy'd back onto the
 * structure, and (c) the shared library will be unloaded. So implementations
 * should do their own internal cleanup in failure circumstances otherwise they
 * could leak. The 'id' parameter, if non-NULL, represents the ENGINE id that
 * the loader is looking for. If this is NULL, the shared library can choose to
 * return failure or to initialise a 'default' ENGINE. If non-NULL, the shared
 * library must initialise only an ENGINE matching the passed 'id'. The function
 * is expected to be implemented with the symbol name "bind_engine". A standard
 * implementation can be instantiated with IMPLEMENT_DYNAMIC_BIND_FN(fn) where
 * the parameter 'fn' is a callback function that populates the ENGINE structure
 * and returns an int value (zero for failure). 'fn' should have prototype;
 *   [static] int fn(ENGINE* e, const(char)* id); */
alias ExternC!(int function(ENGINE* e, const(char)* id,
				const(dynamic_fns)* fns)) dynamic_bind_engine;
template IMPLEMENT_DYNAMIC_BIND_FN(fn) {
	enum IMPLEMENT_DYNAMIC_BIND_FN = "
	extern(C)
	int bind_engine(ENGINE* e, const(char)* id, const(dynamic_fns)* fns);
	extern(C)
	int bind_engine(ENGINE* e, const(char)* id, const(dynamic_fns)* fns) {
		if(ENGINE_get_static_state() == fns->static_state) goto skip_cbs;
		if(!CRYPTO_set_mem_functions(fns->mem_fns.malloc_cb,
			fns->mem_fns.realloc_cb, fns->mem_fns.free_cb))
			return 0;
		CRYPTO_set_locking_callback(fns->lock_fns.lock_locking_cb);
		CRYPTO_set_add_lock_callback(fns->lock_fns.lock_add_lock_cb);
		CRYPTO_set_dynlock_create_callback(fns->lock_fns.dynlock_create_cb);
		CRYPTO_set_dynlock_lock_callback(fns->lock_fns.dynlock_lock_cb);
		CRYPTO_set_dynlock_destroy_callback(fns->lock_fns.dynlock_destroy_cb);
		if(!CRYPTO_set_ex_data_implementation(fns->ex_data_fns))
			return 0;
		if(!ERR_set_implementation(fns->err_fns)) return 0;
	skip_cbs:
		if(!" ~ fn ~ "(e,id)) return 0;
		return 1; }
	";
}

/* If the loading application (or library) and the loaded ENGINE library share
 * the same static data (eg. they're both dynamically linked to the same
 * libcrypto.so) we need a way to avoid trying to set system callbacks - this
 * would fail, and for the same reason that it's unnecessary to try. If the
 * loaded ENGINE has (or gets from through the loader) its own copy of the
 * libcrypto static data, we will need to set the callbacks. The easiest way to
 * detect this is to have a function that returns a pointer to some static data
 * and let the loading application and loaded ENGINE compare their respective
 * values. */
void* ENGINE_get_static_state();

version (BSD) {
void ENGINE_setup_bsd_cryptodev();
}
version (HAVE_CRYPTODEV) {
void ENGINE_setup_bsd_cryptodev();
}

/* BEGIN ERROR CODES */
/* The following lines are auto generated by the script mkerr.pl. Any changes
 * made after this point may be overwritten when the script is next run.
 */
void ERR_load_ENGINE_strings();

/* Error codes for the ENGINE functions. */

/* Function codes. */
enum ENGINE_F_DYNAMIC_CTRL = 180;
enum ENGINE_F_DYNAMIC_GET_DATA_CTX = 181;
enum ENGINE_F_DYNAMIC_LOAD = 182;
enum ENGINE_F_DYNAMIC_SET_DATA_CTX = 183;
enum ENGINE_F_ENGINE_ADD = 105;
enum ENGINE_F_ENGINE_BY_ID = 106;
enum ENGINE_F_ENGINE_CMD_IS_EXECUTABLE = 170;
enum ENGINE_F_ENGINE_CTRL = 142;
enum ENGINE_F_ENGINE_CTRL_CMD = 178;
enum ENGINE_F_ENGINE_CTRL_CMD_STRING = 171;
enum ENGINE_F_ENGINE_FINISH = 107;
enum ENGINE_F_ENGINE_FREE_UTIL = 108;
enum ENGINE_F_ENGINE_GET_CIPHER = 185;
enum ENGINE_F_ENGINE_GET_DEFAULT_TYPE = 177;
enum ENGINE_F_ENGINE_GET_DIGEST = 186;
enum ENGINE_F_ENGINE_GET_NEXT = 115;
enum ENGINE_F_ENGINE_GET_PKEY_ASN1_METH = 193;
enum ENGINE_F_ENGINE_GET_PKEY_METH = 192;
enum ENGINE_F_ENGINE_GET_PREV = 116;
enum ENGINE_F_ENGINE_INIT = 119;
enum ENGINE_F_ENGINE_LIST_ADD = 120;
enum ENGINE_F_ENGINE_LIST_REMOVE = 121;
enum ENGINE_F_ENGINE_LOAD_PRIVATE_KEY = 150;
enum ENGINE_F_ENGINE_LOAD_PUBLIC_KEY = 151;
enum ENGINE_F_ENGINE_LOAD_SSL_CLIENT_CERT = 194;
enum ENGINE_F_ENGINE_NEW = 122;
enum ENGINE_F_ENGINE_REMOVE = 123;
enum ENGINE_F_ENGINE_SET_DEFAULT_STRING = 189;
enum ENGINE_F_ENGINE_SET_DEFAULT_TYPE = 126;
enum ENGINE_F_ENGINE_SET_ID = 129;
enum ENGINE_F_ENGINE_SET_NAME = 130;
enum ENGINE_F_ENGINE_TABLE_REGISTER = 184;
enum ENGINE_F_ENGINE_UNLOAD_KEY = 152;
enum ENGINE_F_ENGINE_UNLOCKED_FINISH = 191;
enum ENGINE_F_ENGINE_UP_REF = 190;
enum ENGINE_F_INT_CTRL_HELPER = 172;
enum ENGINE_F_INT_ENGINE_CONFIGURE = 188;
enum ENGINE_F_INT_ENGINE_MODULE_INIT = 187;
enum ENGINE_F_LOG_MESSAGE = 141;

/* Reason codes. */
enum ENGINE_R_ALREADY_LOADED = 100;
enum ENGINE_R_ARGUMENT_IS_NOT_A_NUMBER = 133;
enum ENGINE_R_CMD_NOT_EXECUTABLE = 134;
enum ENGINE_R_COMMAND_TAKES_INPUT = 135;
enum ENGINE_R_COMMAND_TAKES_NO_INPUT = 136;
enum ENGINE_R_CONFLICTING_ENGINE_ID = 103;
enum ENGINE_R_CTRL_COMMAND_NOT_IMPLEMENTED = 119;
enum ENGINE_R_DH_NOT_IMPLEMENTED = 139;
enum ENGINE_R_DSA_NOT_IMPLEMENTED = 140;
enum ENGINE_R_DSO_FAILURE = 104;
enum ENGINE_R_DSO_NOT_FOUND = 132;
enum ENGINE_R_ENGINES_SECTION_ERROR = 148;
enum ENGINE_R_ENGINE_CONFIGURATION_ERROR = 102;
enum ENGINE_R_ENGINE_IS_NOT_IN_LIST = 105;
enum ENGINE_R_ENGINE_SECTION_ERROR = 149;
enum ENGINE_R_FAILED_LOADING_PRIVATE_KEY = 128;
enum ENGINE_R_FAILED_LOADING_PUBLIC_KEY = 129;
enum ENGINE_R_FINISH_FAILED = 106;
enum ENGINE_R_GET_HANDLE_FAILED = 107;
enum ENGINE_R_ID_OR_NAME_MISSING = 108;
enum ENGINE_R_INIT_FAILED = 109;
enum ENGINE_R_INTERNAL_LIST_ERROR = 110;
enum ENGINE_R_INVALID_ARGUMENT = 143;
enum ENGINE_R_INVALID_CMD_NAME = 137;
enum ENGINE_R_INVALID_CMD_NUMBER = 138;
enum ENGINE_R_INVALID_INIT_VALUE = 151;
enum ENGINE_R_INVALID_STRING = 150;
enum ENGINE_R_NOT_INITIALISED = 117;
enum ENGINE_R_NOT_LOADED = 112;
enum ENGINE_R_NO_CONTROL_FUNCTION = 120;
enum ENGINE_R_NO_INDEX = 144;
enum ENGINE_R_NO_LOAD_FUNCTION = 125;
enum ENGINE_R_NO_REFERENCE = 130;
enum ENGINE_R_NO_SUCH_ENGINE = 116;
enum ENGINE_R_NO_UNLOAD_FUNCTION = 126;
enum ENGINE_R_PROVIDE_PARAMETERS = 113;
enum ENGINE_R_RSA_NOT_IMPLEMENTED = 141;
enum ENGINE_R_UNIMPLEMENTED_CIPHER = 146;
enum ENGINE_R_UNIMPLEMENTED_DIGEST = 147;
enum ENGINE_R_UNIMPLEMENTED_PUBLIC_KEY_METHOD = 101;
enum ENGINE_R_VERSION_INCOMPATIBILITY = 145;
