/* asn1t.h */
/* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL
 * project 2000.
 */
/* ====================================================================
 * Copyright (c) 2000-2005 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).
 *
 */
module deimos.openssl.asn1t;

import deimos.openssl._d_util;

import deimos.openssl.ossl_typ; // Needed for ASN1_BOOLEAN, etc.

import core.stdc.config;
public import deimos.openssl.e_os2;
public import deimos.openssl.asn1;


/* ASN1 template defines, structures and functions */

extern (C):
nothrow:

/+ FIXME: Not yet ported.
#ifndef OPENSSL_EXPORT_VAR_AS_FUNCTION

/* Macro to obtain ASN1_ADB pointer from a type (only used internally) */
#define ASN1_ADB_ptr(iptr) ((const(ASN1_ADB)*)(iptr))


/* Macros for start and end of ASN1_ITEM definition */

#define ASN1_ITEM_start(itname) \
	OPENSSL_GLOBAL const ASN1_ITEM itname##_it = {

#define ASN1_ITEM_end(itname) \
		};

#else

/* Macro to obtain ASN1_ADB pointer from a type (only used internally) */
#define ASN1_ADB_ptr(iptr) ((const(ASN1_ADB)*)(iptr()))


/* Macros for start and end of ASN1_ITEM definition */

#define ASN1_ITEM_start(itname) \
	const(ASN1_ITEM)* itname##_it() \
	{ \
		static const ASN1_ITEM local_it = {

#define ASN1_ITEM_end(itname) \
		}; \
	return &local_it; \
	}

#endif


/* Macros to aid ASN1 template writing */

#define ASN1_ITEM_TEMPLATE(tname) \
	static const ASN1_TEMPLATE tname##_item_tt

#define ASN1_ITEM_TEMPLATE_END(tname) \
	;\
	ASN1_ITEM_start(tname) \
		ASN1_ITYPE_PRIMITIVE,\
		-1,\
		&tname##_item_tt,\
		0,\
		NULL,\
		0,\
		#tname \
	ASN1_ITEM_end(tname)


/* This is a ASN1 type which just embeds a template */

/* This pair helps declare a SEQUENCE. We can do:
 *
 * 	ASN1_SEQUENCE(stname) = {
 * 		... SEQUENCE components ...
 * 	} ASN1_SEQUENCE_END(stname)
 *
 * 	This will produce an ASN1_ITEM called stname_it
 *	for a structure called stname.
 *
 * 	If you want the same structure but a different
 *	name then use:
 *
 * 	ASN1_SEQUENCE(itname) = {
 * 		... SEQUENCE components ...
 * 	} ASN1_SEQUENCE_END_name(stname, itname)
 *
 *	This will create an item called itname_it using
 *	a structure called stname.
 */

#define ASN1_SEQUENCE(tname) \
	static const ASN1_TEMPLATE[] tname##_seq_tt

#define ASN1_SEQUENCE_END(stname) ASN1_SEQUENCE_END_name(stname, stname)

#define ASN1_SEQUENCE_END_name(stname, tname) \
	;\
	ASN1_ITEM_start(tname) \
		ASN1_ITYPE_SEQUENCE,\
		V_ASN1_SEQUENCE,\
		tname##_seq_tt,\
		sizeof(tname##_seq_tt) / sizeof(ASN1_TEMPLATE),\
		NULL,\
		sizeof(stname),\
		#stname \
	ASN1_ITEM_end(tname)

#define ASN1_NDEF_SEQUENCE(tname) \
	ASN1_SEQUENCE(tname)

#define ASN1_NDEF_SEQUENCE_cb(tname, cb) \
	ASN1_SEQUENCE_cb(tname, cb)

#define ASN1_SEQUENCE_cb(tname, cb) \
	static const ASN1_AUX tname##_aux = {NULL, 0, 0, 0, cb, 0}; \
	ASN1_SEQUENCE(tname)

#define ASN1_BROKEN_SEQUENCE(tname) \
	static const ASN1_AUX tname##_aux = {NULL, ASN1_AFLG_BROKEN, 0, 0, 0, 0}; \
	ASN1_SEQUENCE(tname)

#define ASN1_SEQUENCE_ref(tname, cb, lck) \
	static const ASN1_AUX tname##_aux = {NULL, ASN1_AFLG_REFCOUNT, offsetof(tname, references), lck, cb, 0}; \
	ASN1_SEQUENCE(tname)

#define ASN1_SEQUENCE_enc(tname, enc, cb) \
	static const ASN1_AUX tname##_aux = {NULL, ASN1_AFLG_ENCODING, 0, 0, cb, offsetof(tname, enc)}; \
	ASN1_SEQUENCE(tname)

#define ASN1_NDEF_SEQUENCE_END(tname) \
	;\
	ASN1_ITEM_start(tname) \
		ASN1_ITYPE_NDEF_SEQUENCE,\
		V_ASN1_SEQUENCE,\
		tname##_seq_tt,\
		sizeof(tname##_seq_tt) / sizeof(ASN1_TEMPLATE),\
		NULL,\
		sizeof(tname),\
		#tname \
	ASN1_ITEM_end(tname)

#define ASN1_BROKEN_SEQUENCE_END(stname) ASN1_SEQUENCE_END_ref(stname, stname)

#define ASN1_SEQUENCE_END_enc(stname, tname) ASN1_SEQUENCE_END_ref(stname, tname)

#define ASN1_SEQUENCE_END_cb(stname, tname) ASN1_SEQUENCE_END_ref(stname, tname)

#define ASN1_SEQUENCE_END_ref(stname, tname) \
	;\
	ASN1_ITEM_start(tname) \
		ASN1_ITYPE_SEQUENCE,\
		V_ASN1_SEQUENCE,\
		tname##_seq_tt,\
		sizeof(tname##_seq_tt) / sizeof(ASN1_TEMPLATE),\
		&tname##_aux,\
		sizeof(stname),\
		#stname \
	ASN1_ITEM_end(tname)

#define ASN1_NDEF_SEQUENCE_END_cb(stname, tname) \
	;\
	ASN1_ITEM_start(tname) \
		ASN1_ITYPE_NDEF_SEQUENCE,\
		V_ASN1_SEQUENCE,\
		tname##_seq_tt,\
		sizeof(tname##_seq_tt) / sizeof(ASN1_TEMPLATE),\
		&tname##_aux,\
		sizeof(stname),\
		#stname \
	ASN1_ITEM_end(tname)


/* This pair helps declare a CHOICE type. We can do:
 *
 * 	ASN1_CHOICE(chname) = {
 * 		... CHOICE options ...
 * 	ASN1_CHOICE_END(chname)
 *
 * 	This will produce an ASN1_ITEM called chname_it
 *	for a structure called chname. The structure
 *	definition must look like this:
 *	typedef struct {
 *		int type;
 *		union {
 *			ASN1_SOMETHING* opt1;
 *			ASN1_SOMEOTHER* opt2;
 *		} value;
 *	} chname;
 *
 *	the name of the selector must be 'type'.
 * 	to use an alternative selector name use the
 *     ASN1_CHOICE_END_selector() version.
 */

#define ASN1_CHOICE(tname) \
	static const ASN1_TEMPLATE[] tname##_ch_tt

#define ASN1_CHOICE_cb(tname, cb) \
	static const ASN1_AUX tname##_aux = {NULL, 0, 0, 0, cb, 0}; \
	ASN1_CHOICE(tname)

#define ASN1_CHOICE_END(stname) ASN1_CHOICE_END_name(stname, stname)

#define ASN1_CHOICE_END_name(stname, tname) ASN1_CHOICE_END_selector(stname, tname, type)

#define ASN1_CHOICE_END_selector(stname, tname, selname) \
	;\
	ASN1_ITEM_start(tname) \
		ASN1_ITYPE_CHOICE,\
		offsetof(stname,selname) ,\
		tname##_ch_tt,\
		sizeof(tname##_ch_tt) / sizeof(ASN1_TEMPLATE),\
		NULL,\
		sizeof(stname),\
		#stname \
	ASN1_ITEM_end(tname)

#define ASN1_CHOICE_END_cb(stname, tname, selname) \
	;\
	ASN1_ITEM_start(tname) \
		ASN1_ITYPE_CHOICE,\
		offsetof(stname,selname) ,\
		tname##_ch_tt,\
		sizeof(tname##_ch_tt) / sizeof(ASN1_TEMPLATE),\
		&tname##_aux,\
		sizeof(stname),\
		#stname \
	ASN1_ITEM_end(tname)

/* This helps with the template wrapper form of ASN1_ITEM */

#define ASN1_EX_TEMPLATE_TYPE(flags, tag, name, type) { \
	(flags), (tag), 0,\
	#name, ASN1_ITEM_ref(type) }

/* These help with SEQUENCE or CHOICE components */

/* used to declare other types */

#define ASN1_EX_TYPE(flags, tag, stname, field, type) { \
	(flags), (tag), offsetof(stname, field),\
	#field, ASN1_ITEM_ref(type) }

/* used when the structure is combined with the parent */

#define ASN1_EX_COMBINE(flags, tag, type) { \
	(flags)|ASN1_TFLG_COMBINE, (tag), 0, NULL, ASN1_ITEM_ref(type) }

/* implicit and explicit helper macros */

#define ASN1_IMP_EX(stname, field, type, tag, ex) \
		ASN1_EX_TYPE(ASN1_TFLG_IMPLICIT | ex, tag, stname, field, type)

#define ASN1_EXP_EX(stname, field, type, tag, ex) \
		ASN1_EX_TYPE(ASN1_TFLG_EXPLICIT | ex, tag, stname, field, type)

/* Any defined by macros: the field used is in the table itself */

#ifndef OPENSSL_EXPORT_VAR_AS_FUNCTION
#define ASN1_ADB_OBJECT(tblname) { ASN1_TFLG_ADB_OID, -1, 0, #tblname, (const(ASN1_ITEM)*)&(tblname##_adb) }
#define ASN1_ADB_INTEGER(tblname) { ASN1_TFLG_ADB_INT, -1, 0, #tblname, (const(ASN1_ITEM)*)&(tblname##_adb) }
#else
#define ASN1_ADB_OBJECT(tblname) { ASN1_TFLG_ADB_OID, -1, 0, #tblname, tblname##_adb }
#define ASN1_ADB_INTEGER(tblname) { ASN1_TFLG_ADB_INT, -1, 0, #tblname, tblname##_adb }
#endif
/* Plain simple type */
#define ASN1_SIMPLE(stname, field, type) ASN1_EX_TYPE(0,0, stname, field, type)

/* OPTIONAL simple type */
#define ASN1_OPT(stname, field, type) ASN1_EX_TYPE(ASN1_TFLG_OPTIONAL, 0, stname, field, type)

/* IMPLICIT tagged simple type */
#define ASN1_IMP(stname, field, type, tag) ASN1_IMP_EX(stname, field, type, tag, 0)

/* IMPLICIT tagged OPTIONAL simple type */
#define ASN1_IMP_OPT(stname, field, type, tag) ASN1_IMP_EX(stname, field, type, tag, ASN1_TFLG_OPTIONAL)

/* Same as above but EXPLICIT */

#define ASN1_EXP(stname, field, type, tag) ASN1_EXP_EX(stname, field, type, tag, 0)
#define ASN1_EXP_OPT(stname, field, type, tag) ASN1_EXP_EX(stname, field, type, tag, ASN1_TFLG_OPTIONAL)

/* SEQUENCE OF type */
#define ASN1_SEQUENCE_OF(stname, field, type) \
		ASN1_EX_TYPE(ASN1_TFLG_SEQUENCE_OF, 0, stname, field, type)

/* OPTIONAL SEQUENCE OF */
#define ASN1_SEQUENCE_OF_OPT(stname, field, type) \
		ASN1_EX_TYPE(ASN1_TFLG_SEQUENCE_OF|ASN1_TFLG_OPTIONAL, 0, stname, field, type)

/* Same as above but for SET OF */

#define ASN1_SET_OF(stname, field, type) \
		ASN1_EX_TYPE(ASN1_TFLG_SET_OF, 0, stname, field, type)

#define ASN1_SET_OF_OPT(stname, field, type) \
		ASN1_EX_TYPE(ASN1_TFLG_SET_OF|ASN1_TFLG_OPTIONAL, 0, stname, field, type)

/* Finally compound types of SEQUENCE, SET, IMPLICIT, EXPLICIT and OPTIONAL */

#define ASN1_IMP_SET_OF(stname, field, type, tag) \
			ASN1_IMP_EX(stname, field, type, tag, ASN1_TFLG_SET_OF)

#define ASN1_EXP_SET_OF(stname, field, type, tag) \
			ASN1_EXP_EX(stname, field, type, tag, ASN1_TFLG_SET_OF)

#define ASN1_IMP_SET_OF_OPT(stname, field, type, tag) \
			ASN1_IMP_EX(stname, field, type, tag, ASN1_TFLG_SET_OF|ASN1_TFLG_OPTIONAL)

#define ASN1_EXP_SET_OF_OPT(stname, field, type, tag) \
			ASN1_EXP_EX(stname, field, type, tag, ASN1_TFLG_SET_OF|ASN1_TFLG_OPTIONAL)

#define ASN1_IMP_SEQUENCE_OF(stname, field, type, tag) \
			ASN1_IMP_EX(stname, field, type, tag, ASN1_TFLG_SEQUENCE_OF)

#define ASN1_IMP_SEQUENCE_OF_OPT(stname, field, type, tag) \
			ASN1_IMP_EX(stname, field, type, tag, ASN1_TFLG_SEQUENCE_OF|ASN1_TFLG_OPTIONAL)

#define ASN1_EXP_SEQUENCE_OF(stname, field, type, tag) \
			ASN1_EXP_EX(stname, field, type, tag, ASN1_TFLG_SEQUENCE_OF)

#define ASN1_EXP_SEQUENCE_OF_OPT(stname, field, type, tag) \
			ASN1_EXP_EX(stname, field, type, tag, ASN1_TFLG_SEQUENCE_OF|ASN1_TFLG_OPTIONAL)

/* EXPLICIT using indefinite length constructed form */
#define ASN1_NDEF_EXP(stname, field, type, tag) \
			ASN1_EXP_EX(stname, field, type, tag, ASN1_TFLG_NDEF)

/* EXPLICIT OPTIONAL using indefinite length constructed form */
#define ASN1_NDEF_EXP_OPT(stname, field, type, tag) \
			ASN1_EXP_EX(stname, field, type, tag, ASN1_TFLG_OPTIONAL|ASN1_TFLG_NDEF)

/* Macros for the ASN1_ADB structure */

#define ASN1_ADB(name) \
	static const ASN1_ADB_TABLE[] name##_adbtbl

#ifndef OPENSSL_EXPORT_VAR_AS_FUNCTION

#define ASN1_ADB_END(name, flags, field, app_table, def, none) \
	;\
	static const ASN1_ADB name##_adb = {\
		flags,\
		offsetof(name, field),\
		app_table,\
		name##_adbtbl,\
		sizeof(name##_adbtbl) / sizeof(ASN1_ADB_TABLE),\
		def,\
		none\
	}

#else

#define ASN1_ADB_END(name, flags, field, app_table, def, none) \
	;\
	static const(ASN1_ITEM)* name##_adb() \
	{ \
	static const ASN1_ADB internal_adb = \
		{\
		flags,\
		offsetof(name, field),\
		app_table,\
		name##_adbtbl,\
		sizeof(name##_adbtbl) / sizeof(ASN1_ADB_TABLE),\
		def,\
		none\
		}; \
		return (const(ASN1_ITEM)*) &internal_adb; \
	} \
	void dummy_function()

#endif

#define ADB_ENTRY(val, template) {val, template}

#define ASN1_ADB_TEMPLATE(name) \
	static const ASN1_TEMPLATE name##_tt
+/
/* This is the ASN1 template structure that defines
 * a wrapper round the actual type. It determines the
 * actual position of the field in the value structure,
 * various flags such as OPTIONAL and the field name.
 */

struct ASN1_TEMPLATE_st {
c_ulong flags;		/* Various flags */
c_long tag;			/* tag, not used if no tagging */
c_ulong offset;		/* Offset of this field in structure */
version (NO_ASN1_FIELD_NAMES) {} else {
const(char)* field_name;		/* Field name */
}
ASN1_ITEM_EXP* item;		/* Relevant ASN1_ITEM or ASN1_ADB */
};

/* Macro to extract ASN1_ITEM and ASN1_ADB pointer from ASN1_TEMPLATE */

auto ASN1_TEMPLATE_item()(ASN1_TEMPLATE_st* t) { return (t.item_ptr); }
auto ASN1_TEMPLATE_adb()(ASN1_TEMPLATE_st* t) { return (t.item_ptr); }

alias ASN1_ADB_TABLE_st ASN1_ADB_TABLE;
alias ASN1_ADB_st ASN1_ADB;

struct ASN1_ADB_st {
	c_ulong flags;	/* Various flags */
	c_ulong offset;	/* Offset of selector field */
	STACK_OF!(ASN1_ADB_TABLE) **app_items; /* Application defined items */
	const(ASN1_ADB_TABLE)* tbl;	/* Table of possible types */
	c_long tblcount;		/* Number of entries in tbl */
	const(ASN1_TEMPLATE)* default_tt;  /* Type to use if no match */
	const(ASN1_TEMPLATE)* null_tt;  /* Type to use if selector is NULL */
};

struct ASN1_ADB_TABLE_st {
	c_long value;		/* NID for an object or value for an int */
	const ASN1_TEMPLATE tt;		/* item for this value */
};

/* template flags */

/* Field is optional */
enum ASN1_TFLG_OPTIONAL = (0x1);

/* Field is a SET OF */
enum ASN1_TFLG_SET_OF = (0x1 << 1);

/* Field is a SEQUENCE OF */
enum ASN1_TFLG_SEQUENCE_OF = (0x2 << 1);

/* Special case: this refers to a SET OF that
 * will be sorted into DER order when encoded* and*
 * the corresponding STACK will be modified to match
 * the new order.
 */
enum ASN1_TFLG_SET_ORDER = (0x3 << 1);

/* Mask for SET OF or SEQUENCE OF */
enum ASN1_TFLG_SK_MASK = (0x3 << 1);

/* These flags mean the tag should be taken from the
 * tag field. If EXPLICIT then the underlying type
 * is used for the inner tag.
 */

/* IMPLICIT tagging */
enum ASN1_TFLG_IMPTAG = (0x1 << 3);


/* EXPLICIT tagging, inner tag from underlying type */
enum ASN1_TFLG_EXPTAG = (0x2 << 3);

enum ASN1_TFLG_TAG_MASK = (0x3 << 3);

/* context specific IMPLICIT */
enum ASN1_TFLG_IMPLICIT = ASN1_TFLG_IMPTAG|ASN1_TFLG_CONTEXT;

/* context specific EXPLICIT */
enum ASN1_TFLG_EXPLICIT = ASN1_TFLG_EXPTAG|ASN1_TFLG_CONTEXT;

/* If tagging is in force these determine the
 * type of tag to use. Otherwise the tag is
 * determined by the underlying type. These
 * values reflect the actual octet format.
 */

/* Universal tag */
enum ASN1_TFLG_UNIVERSAL = (0x0<<6);
/* Application tag */
enum ASN1_TFLG_APPLICATION = (0x1<<6);
/* Context specific tag */
enum ASN1_TFLG_CONTEXT = (0x2<<6);
/* Private tag */
enum ASN1_TFLG_PRIVATE = (0x3<<6);

enum ASN1_TFLG_TAG_CLASS = (0x3<<6);

/* These are for ANY DEFINED BY type. In this case
 * the 'item' field points to an ASN1_ADB structure
 * which contains a table of values to decode the
 * relevant type
 */

enum ASN1_TFLG_ADB_MASK = (0x3<<8);

enum ASN1_TFLG_ADB_OID = (0x1<<8);

enum ASN1_TFLG_ADB_INT = (0x1<<9);

/* This flag means a parent structure is passed
 * instead of the field: this is useful is a
 * SEQUENCE is being combined with a CHOICE for
 * example. Since this means the structure and
 * item name will differ we need to use the
 * ASN1_CHOICE_END_name() macro for example.
 */

enum ASN1_TFLG_COMBINE = (0x1<<10);

/* This flag when present in a SEQUENCE OF, SET OF
 * or EXPLICIT causes indefinite length constructed
 * encoding to be used if required.
 */

enum ASN1_TFLG_NDEF = (0x1<<11);

/* This is the actual ASN1 item itself */

struct ASN1_ITEM_st {
char itype;			/* The item type, primitive, SEQUENCE, CHOICE or extern */
c_long utype;			/* underlying type */
const(ASN1_TEMPLATE)* templates;	/* If SEQUENCE or CHOICE this contains the contents */
c_long tcount;			/* Number of templates if SEQUENCE or CHOICE */
const(void)* funcs;		/* functions that handle this type */
c_long size;			/* Structure size (usually)*/
version (NO_ASN1_FIELD_NAMES) {} else {
const(char)* sname;		/* Structure name */
}
};

/* These are values for the itype field and
 * determine how the type is interpreted.
 *
 * For PRIMITIVE types the underlying type
 * determines the behaviour if items is NULL.
 *
 * Otherwise templates must contain a single
 * template and the type is treated in the
 * same way as the type specified in the template.
 *
 * For SEQUENCE types the templates field points
 * to the members, the size field is the
 * structure size.
 *
 * For CHOICE types the templates field points
 * to each possible member (typically a union)
 * and the 'size' field is the offset of the
 * selector.
 *
 * The 'funcs' field is used for application
 * specific functions.
 *
 * For COMPAT types the funcs field gives a
 * set of functions that handle this type, this
 * supports the old d2i, i2d convention.
 *
 * The EXTERN type uses a new style d2i/i2d.
 * The new style should be used where possible
 * because it avoids things like the d2i IMPLICIT
 * hack.
 *
 * MSTRING is a multiple string type, it is used
 * for a CHOICE of character strings where the
 * actual strings all occupy an ASN1_STRING
 * structure. In this case the 'utype' field
 * has a special meaning, it is used as a mask
 * of acceptable types using the B_ASN1 constants.
 *
 * NDEF_SEQUENCE is the same as SEQUENCE except
 * that it will use indefinite length constructed
 * encoding if requested.
 *
 */

enum ASN1_ITYPE_PRIMITIVE = 0x0;

enum ASN1_ITYPE_SEQUENCE = 0x1;

enum ASN1_ITYPE_CHOICE = 0x2;

enum ASN1_ITYPE_COMPAT = 0x3;

enum ASN1_ITYPE_EXTERN = 0x4;

enum ASN1_ITYPE_MSTRING = 0x5;

enum ASN1_ITYPE_NDEF_SEQUENCE = 0x6;

/* Cache for ASN1 tag and length, so we
 * don't keep re-reading it for things
 * like CHOICE
 */

struct ASN1_TLC_st{
	char valid;	/* Values below are valid */
	int ret;	/* return value */
	c_long plen;	/* length */
	int ptag;	/* class value */
	int pclass;	/* class value */
	int hdrlen;	/* header length */
};

/* Typedefs for ASN1 function pointers */

alias typeof(*(ExternC!(ASN1_VALUE* function())).init) ASN1_new_func;
alias typeof(*(ExternC!(void function(ASN1_VALUE* a))).init) ASN1_free_func;
alias typeof(*(ExternC!(ASN1_VALUE* function(ASN1_VALUE** a, const(ubyte)** in_, c_long length))).init) ASN1_d2i_func;
alias typeof(*(ExternC!(int function(ASN1_VALUE* a, ubyte** in_))).init) ASN1_i2d_func;

alias typeof(*(ExternC!(int function(ASN1_VALUE** pval, const(ubyte)** in_, c_long len, const(ASN1_ITEM)* it,
					int tag, int aclass, char opt, ASN1_TLC* ctx))).init) ASN1_ex_d2i;

alias typeof(*(ExternC!(int function(ASN1_VALUE** pval, ubyte** out_, const(ASN1_ITEM)* it, int tag, int aclass))).init) ASN1_ex_i2d;
alias typeof(*(ExternC!(int function(ASN1_VALUE** pval, const(ASN1_ITEM)* it))).init) ASN1_ex_new_func;
alias typeof(*(ExternC!(void function(ASN1_VALUE** pval, const(ASN1_ITEM)* it))).init) ASN1_ex_free_func;

alias typeof(*(ExternC!(int function(BIO* out_, ASN1_VALUE** pval,
						int indent, const(char)* fname,
						const(ASN1_PCTX)* pctx))).init) ASN1_ex_print_func;

alias typeof(*(ExternC!(int function(ASN1_VALUE** pval, ubyte* cont, int* putype, const(ASN1_ITEM)* it))).init) ASN1_primitive_i2c;
alias typeof(*(ExternC!(int function(ASN1_VALUE** pval, const(ubyte)* cont, int len, int utype, char* free_cont, const(ASN1_ITEM)* it))).init) ASN1_primitive_c2i;
alias typeof(*(ExternC!(int function(BIO* out_, ASN1_VALUE** pval, const(ASN1_ITEM)* it, int indent, const(ASN1_PCTX)* pctx))).init) ASN1_primitive_print;

struct ASN1_COMPAT_FUNCS_st {
	ASN1_new_func* asn1_new;
	ASN1_free_func* asn1_free;
	ASN1_d2i_func* asn1_d2i;
	ASN1_i2d_func* asn1_i2d;
}
alias ASN1_COMPAT_FUNCS_st ASN1_COMPAT_FUNCS;

struct ASN1_EXTERN_FUNCS_st {
	void* app_data;
	ASN1_ex_new_func* asn1_ex_new;
	ASN1_ex_free_func* asn1_ex_free;
	ASN1_ex_free_func* asn1_ex_clear;
	ASN1_ex_d2i* asn1_ex_d2i;
	ASN1_ex_i2d* asn1_ex_i2d;
	ASN1_ex_print_func* asn1_ex_print;
}
alias ASN1_EXTERN_FUNCS_st ASN1_EXTERN_FUNCS;

struct ASN1_PRIMITIVE_FUNCS_st {
	void* app_data;
	c_ulong flags;
	ASN1_ex_new_func* prim_new;
	ASN1_ex_free_func* prim_free;
	ASN1_ex_free_func* prim_clear;
	ASN1_primitive_c2i* prim_c2i;
	ASN1_primitive_i2c* prim_i2c;
	ASN1_primitive_print* prim_print;
}
alias ASN1_PRIMITIVE_FUNCS_st ASN1_PRIMITIVE_FUNCS;

/* This is the ASN1_AUX structure: it handles various
 * miscellaneous requirements. For example the use of
 * reference counts and an informational callback.
 *
 * The "informational callback" is called at various
 * points during the ASN1 encoding and decoding. It can
 * be used to provide minor customisation of the structures
 * used. This is most useful where the supplied routines
 ** almost* do the right thing but need some extra help
 * at a few points. If the callback returns zero then
 * it is assumed a fatal error has occurred and the
 * main operation should be abandoned.
 *
 * If major changes in the default behaviour are required
 * then an external type is more appropriate.
 */

alias typeof(*(ExternC!(int function(int operation, ASN1_VALUE** in_, const(ASN1_ITEM)* it,
				void* exarg))).init) ASN1_aux_cb;

struct ASN1_AUX_st {
	void* app_data;
	int flags;
	int ref_offset;		/* Offset of reference value */
	int ref_lock;		/* Lock type to use */
	ASN1_aux_cb* asn1_cb;
	int enc_offset;		/* Offset of ASN1_ENCODING structure */
}
alias ASN1_AUX_st ASN1_AUX;

/* For print related callbacks exarg points to this structure */
struct ASN1_PRINT_ARG_st {
	BIO* out_;
	int indent;
	const(ASN1_PCTX)* pctx;
}
alias ASN1_PRINT_ARG_st ASN1_PRINT_ARG;

/* For streaming related callbacks exarg points to this structure */
struct ASN1_STREAM_ARG_st {
	/* BIO to stream through */
	BIO* out_;
	/* BIO with filters appended */
	BIO* ndef_bio;
	/* Streaming I/O boundary */
	ubyte** boundary;
}
alias ASN1_STREAM_ARG_st ASN1_STREAM_ARG;

/* Flags in ASN1_AUX */

/* Use a reference count */
enum ASN1_AFLG_REFCOUNT = 1;
/* Save the encoding of structure (useful for signatures) */
enum ASN1_AFLG_ENCODING = 2;
/* The Sequence length is invalid */
enum ASN1_AFLG_BROKEN = 4;

/* operation values for asn1_cb */

enum ASN1_OP_NEW_PRE = 0;
enum ASN1_OP_NEW_POST = 1;
enum ASN1_OP_FREE_PRE = 2;
enum ASN1_OP_FREE_POST = 3;
enum ASN1_OP_D2I_PRE = 4;
enum ASN1_OP_D2I_POST = 5;
enum ASN1_OP_I2D_PRE = 6;
enum ASN1_OP_I2D_POST = 7;
enum ASN1_OP_PRINT_PRE = 8;
enum ASN1_OP_PRINT_POST = 9;
enum ASN1_OP_STREAM_PRE = 10;
enum ASN1_OP_STREAM_POST = 11;
enum ASN1_OP_DETACHED_PRE = 12;
enum ASN1_OP_DETACHED_POST = 13;

/+ FIXME: Not yet ported.
/* Macro to implement a primitive type */
#define IMPLEMENT_ASN1_TYPE(stname) IMPLEMENT_ASN1_TYPE_ex(stname, stname, 0)
#define IMPLEMENT_ASN1_TYPE_ex(itname, vname, ex) \
				ASN1_ITEM_start(itname) \
					ASN1_ITYPE_PRIMITIVE, V_##vname, NULL, 0, NULL, ex, #itname \
				ASN1_ITEM_end(itname)

/* Macro to implement a multi string type */
#define IMPLEMENT_ASN1_MSTRING(itname, mask) \
				ASN1_ITEM_start(itname) \
					ASN1_ITYPE_MSTRING, mask, NULL, 0, NULL, sizeof(ASN1_STRING), #itname \
				ASN1_ITEM_end(itname)

/* Macro to implement an ASN1_ITEM in terms of old style funcs */

#define IMPLEMENT_COMPAT_ASN1(sname) IMPLEMENT_COMPAT_ASN1_type(sname, V_ASN1_SEQUENCE)

#define IMPLEMENT_COMPAT_ASN1_type(sname, tag) \
	static const ASN1_COMPAT_FUNCS sname##_ff = { \
		(ASN1_new_func*)sname##_new, \
		(ASN1_free_func*)sname##_free, \
		(ASN1_d2i_func*)d2i_##sname, \
		(ASN1_i2d_func*)i2d_##sname, \
	}; \
	ASN1_ITEM_start(sname) \
		ASN1_ITYPE_COMPAT, \
		tag, \
		NULL, \
		0, \
		&sname##_ff, \
		0, \
		#sname \
	ASN1_ITEM_end(sname)

#define IMPLEMENT_EXTERN_ASN1(sname, tag, fptrs) \
	ASN1_ITEM_start(sname) \
		ASN1_ITYPE_EXTERN, \
		tag, \
		NULL, \
		0, \
		&fptrs, \
		0, \
		#sname \
	ASN1_ITEM_end(sname)

/* Macro to implement standard functions in terms of ASN1_ITEM structures */

#define IMPLEMENT_ASN1_FUNCTIONS(stname) IMPLEMENT_ASN1_FUNCTIONS_fname(stname, stname, stname)

#define IMPLEMENT_ASN1_FUNCTIONS_name(stname, itname) IMPLEMENT_ASN1_FUNCTIONS_fname(stname, itname, itname)

#define IMPLEMENT_ASN1_FUNCTIONS_ENCODE_name(stname, itname) \
			IMPLEMENT_ASN1_FUNCTIONS_ENCODE_fname(stname, itname, itname)

#define IMPLEMENT_STATIC_ASN1_ALLOC_FUNCTIONS(stname) \
		IMPLEMENT_ASN1_ALLOC_FUNCTIONS_pfname(static, stname, stname, stname)

#define IMPLEMENT_ASN1_ALLOC_FUNCTIONS(stname) \
		IMPLEMENT_ASN1_ALLOC_FUNCTIONS_fname(stname, stname, stname)

#define IMPLEMENT_ASN1_ALLOC_FUNCTIONS_pfname(pre, stname, itname, fname) \
	pre stname* fname##_new() \
	{ \
		return (stname*)ASN1_item_new(ASN1_ITEM_rptr(itname)); \
	} \
	pre void fname##_free(stname* a) \
	{ \
		ASN1_item_free((ASN1_VALUE*)a, ASN1_ITEM_rptr(itname)); \
	}

#define IMPLEMENT_ASN1_ALLOC_FUNCTIONS_fname(stname, itname, fname) \
	stname* fname##_new() \
	{ \
		return (stname*)ASN1_item_new(ASN1_ITEM_rptr(itname)); \
	} \
	void fname##_free(stname* a) \
	{ \
		ASN1_item_free((ASN1_VALUE*)a, ASN1_ITEM_rptr(itname)); \
	}

#define IMPLEMENT_ASN1_FUNCTIONS_fname(stname, itname, fname) \
	IMPLEMENT_ASN1_ENCODE_FUNCTIONS_fname(stname, itname, fname) \
	IMPLEMENT_ASN1_ALLOC_FUNCTIONS_fname(stname, itname, fname)

#define IMPLEMENT_ASN1_ENCODE_FUNCTIONS_fname(stname, itname, fname) \
	stname* d2i_##fname(stname** a, const(ubyte)** in_, c_long len) \
	{ \
		return (stname*)ASN1_item_d2i((ASN1_VALUE**)a, in_, len, ASN1_ITEM_rptr(itname));\
	} \
	int i2d_##fname(stname* a, ubyte** out_) \
	{ \
		return ASN1_item_i2d((ASN1_VALUE*)a, out_, ASN1_ITEM_rptr(itname));\
	}

#define IMPLEMENT_ASN1_NDEF_FUNCTION(stname) \
	int i2d_##stname##_NDEF(stname* a, ubyte** out_) \
	{ \
		return ASN1_item_ndef_i2d((ASN1_VALUE*)a, out_, ASN1_ITEM_rptr(stname));\
	}

/* This includes evil casts to remove const: they will go away when full
 * ASN1 constification is done.
 */
#define IMPLEMENT_ASN1_ENCODE_FUNCTIONS_const_fname(stname, itname, fname) \
	stname* d2i_##fname(stname** a, const(ubyte)** in_, c_long len) \
	{ \
		return (stname*)ASN1_item_d2i((ASN1_VALUE**)a, in_, len, ASN1_ITEM_rptr(itname));\
	} \
	int i2d_##fname(const(stname)* a, ubyte** out_) \
	{ \
		return ASN1_item_i2d((ASN1_VALUE*)a, out_, ASN1_ITEM_rptr(itname));\
	}

#define IMPLEMENT_ASN1_DUP_FUNCTION(stname) \
	stname* stname##_dup(stname* x) \
        { \
        return ASN1_item_dup(ASN1_ITEM_rptr(stname), x); \
        }

#define IMPLEMENT_ASN1_PRINT_FUNCTION(stname) \
	IMPLEMENT_ASN1_PRINT_FUNCTION_fname(stname, stname, stname)

#define IMPLEMENT_ASN1_PRINT_FUNCTION_fname(stname, itname, fname) \
	int fname##_print_ctx(BIO* out_, stname* x, int indent, \
						const(ASN1_PCTX)* pctx) \
	{ \
		return ASN1_item_print(out, (ASN1_VALUE*)x, indent, \
			ASN1_ITEM_rptr(itname), pctx); \
	}

#define IMPLEMENT_ASN1_FUNCTIONS_const(name) \
		IMPLEMENT_ASN1_FUNCTIONS_const_fname(name, name, name)

#define IMPLEMENT_ASN1_FUNCTIONS_const_fname(stname, itname, fname) \
	IMPLEMENT_ASN1_ENCODE_FUNCTIONS_const_fname(stname, itname, fname) \
	IMPLEMENT_ASN1_ALLOC_FUNCTIONS_fname(stname, itname, fname)
+/

/* external definitions for primitive types */

mixin(DECLARE_ASN1_ITEM!"ASN1_BOOLEAN");
mixin(DECLARE_ASN1_ITEM!"ASN1_TBOOLEAN");
mixin(DECLARE_ASN1_ITEM!"ASN1_FBOOLEAN");
mixin(DECLARE_ASN1_ITEM!"ASN1_SEQUENCE");
mixin(DECLARE_ASN1_ITEM!"CBIGNUM");
mixin(DECLARE_ASN1_ITEM!"BIGNUM");
mixin(DECLARE_ASN1_ITEM!"LONG");
mixin(DECLARE_ASN1_ITEM!"ZLONG");

/+mixin DECLARE_STACK_OF!(ASN1_VALUE);+/

/* Functions used internally by the ASN1 code */

int ASN1_item_ex_new(ASN1_VALUE** pval, const(ASN1_ITEM)* it);
void ASN1_item_ex_free(ASN1_VALUE** pval, const(ASN1_ITEM)* it);
int ASN1_template_new(ASN1_VALUE** pval, const(ASN1_TEMPLATE)* tt);
int ASN1_primitive_new(ASN1_VALUE** pval, const(ASN1_ITEM)* it);

void ASN1_template_free(ASN1_VALUE** pval, const(ASN1_TEMPLATE)* tt);
int ASN1_template_d2i(ASN1_VALUE** pval, const(ubyte)** in_, c_long len, const(ASN1_TEMPLATE)* tt);
int ASN1_item_ex_d2i(ASN1_VALUE** pval, const(ubyte)** in_, c_long len, const(ASN1_ITEM)* it,
				int tag, int aclass, char opt, ASN1_TLC* ctx);

int ASN1_item_ex_i2d(ASN1_VALUE** pval, ubyte** out_, const(ASN1_ITEM)* it, int tag, int aclass);
int ASN1_template_i2d(ASN1_VALUE** pval, ubyte** out_, const(ASN1_TEMPLATE)* tt);
void ASN1_primitive_free(ASN1_VALUE** pval, const(ASN1_ITEM)* it);

int asn1_ex_i2c(ASN1_VALUE** pval, ubyte* cont, int* putype, const(ASN1_ITEM)* it);
int asn1_ex_c2i(ASN1_VALUE** pval, const(ubyte)* cont, int len, int utype, char* free_cont, const(ASN1_ITEM)* it);

int asn1_get_choice_selector(ASN1_VALUE** pval, const(ASN1_ITEM)* it);
int asn1_set_choice_selector(ASN1_VALUE** pval, int value, const(ASN1_ITEM)* it);

ASN1_VALUE** asn1_get_field_ptr(ASN1_VALUE** pval, const(ASN1_TEMPLATE)* tt);

const(ASN1_TEMPLATE)* asn1_do_adb(ASN1_VALUE** pval, const(ASN1_TEMPLATE)* tt, int nullerr);

int asn1_do_lock(ASN1_VALUE** pval, int op, const(ASN1_ITEM)* it);

void asn1_enc_init(ASN1_VALUE** pval, const(ASN1_ITEM)* it);
void asn1_enc_free(ASN1_VALUE** pval, const(ASN1_ITEM)* it);
int asn1_enc_restore(int* len, ubyte** out_, ASN1_VALUE** pval, const(ASN1_ITEM)* it);
int asn1_enc_save(ASN1_VALUE** pval, const(ubyte)* in_, int inlen, const(ASN1_ITEM)* it);