struct ASN1_ADB_st {
	unsigned long flags;	/* Various flags */
	unsigned long offset;	/* Offset of selector field */
	STACK_OF(ASN1_ADB_TABLE) **app_items; /* Application defined items */
	const ASN1_ADB_TABLE *tbl;	/* Table of possible types */
	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 {
	long value;		/* NID for an object or value for an int */
	const ASN1_TEMPLATE tt;		/* item for this value */
};

/* template flags */

/* Field is optional */
#define ASN1_TFLG_OPTIONAL	(0x1)

/* Field is a SET OF */
#define ASN1_TFLG_SET_OF	(0x1 << 1)

/* Field is a SEQUENCE OF */
#define 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.
 */
#define ASN1_TFLG_SET_ORDER	(0x3 << 1)

/* Mask for SET OF or SEQUENCE OF */
#define 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 */
#define ASN1_TFLG_IMPTAG	(0x1 << 3)


/* EXPLICIT tagging, inner tag from underlying type */
#define ASN1_TFLG_EXPTAG	(0x2 << 3)

#define ASN1_TFLG_TAG_MASK	(0x3 << 3)

/* context specific IMPLICIT */
#define ASN1_TFLG_IMPLICIT	ASN1_TFLG_IMPTAG|ASN1_TFLG_CONTEXT

/* context specific EXPLICIT */
#define 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 */ 
#define ASN1_TFLG_UNIVERSAL	(0x0<<6)
/* Application tag */ 
#define ASN1_TFLG_APPLICATION	(0x1<<6)
/* Context specific tag */ 
#define ASN1_TFLG_CONTEXT	(0x2<<6)
/* Private tag */ 
#define ASN1_TFLG_PRIVATE	(0x3<<6)

#define 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
 */

#define ASN1_TFLG_ADB_MASK	(0x3<<8)

#define ASN1_TFLG_ADB_OID	(0x1<<8)

#define 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.
 */

#define 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.
 */

#define 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 */
long utype;			/* underlying type */
const ASN1_TEMPLATE *templates;	/* If SEQUENCE or CHOICE this contains the contents */
long tcount;			/* Number of templates if SEQUENCE or CHOICE */
const void *funcs;		/* functions that handle this type */
long size;			/* Structure size (usually)*/
#ifndef NO_ASN1_FIELD_NAMES
const char *sname;		/* Structure name */
#endif
};

/* 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.
 *
 */

#define ASN1_ITYPE_PRIMITIVE		0x0

#define ASN1_ITYPE_SEQUENCE		0x1

#define ASN1_ITYPE_CHOICE		0x2

#define ASN1_ITYPE_COMPAT		0x3

#define ASN1_ITYPE_EXTERN		0x4

#define ASN1_ITYPE_MSTRING		0x5

#define 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 */
	long plen;	/* length */
	int ptag;	/* class value */
	int pclass;	/* class value */
	int hdrlen;	/* header length */
};

/* Typedefs for ASN1 function pointers */

typedef ASN1_VALUE * ASN1_new_func(void);
typedef void ASN1_free_func(ASN1_VALUE *a);
typedef ASN1_VALUE * ASN1_d2i_func(ASN1_VALUE **a, const unsigned char ** in, long length);
typedef int ASN1_i2d_func(ASN1_VALUE * a, unsigned char **in);

typedef int ASN1_ex_d2i(ASN1_VALUE **pval, const unsigned char **in, long len, const ASN1_ITEM *it,
					int tag, int aclass, char opt, ASN1_TLC *ctx);

typedef int ASN1_ex_i2d(ASN1_VALUE **pval, unsigned char **out, const ASN1_ITEM *it, int tag, int aclass);
typedef int ASN1_ex_new_func(ASN1_VALUE **pval, const ASN1_ITEM *it);
typedef void ASN1_ex_free_func(ASN1_VALUE **pval, const ASN1_ITEM *it);

typedef int ASN1_primitive_i2c(ASN1_VALUE **pval, unsigned char *cont, int *putype, const ASN1_ITEM *it);
typedef int ASN1_primitive_c2i(ASN1_VALUE **pval, const unsigned char *cont, int len, int utype, char *free_cont, const ASN1_ITEM *it);

typedef 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;
} ASN1_COMPAT_FUNCS;

typedef 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_EXTERN_FUNCS;

typedef struct ASN1_PRIMITIVE_FUNCS_st {
	void *app_data;
	unsigned long 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_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.
 */

typedef int ASN1_aux_cb(int operation, ASN1_VALUE **in, const ASN1_ITEM *it);

typedef 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 */
} ASN1_AUX;

/* Flags in ASN1_AUX */

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

/* operation values for asn1_cb */

#define ASN1_OP_NEW_PRE		0
#define ASN1_OP_NEW_POST	1
#define ASN1_OP_FREE_PRE	2
#define ASN1_OP_FREE_POST	3
#define ASN1_OP_D2I_PRE		4
#define ASN1_OP_D2I_POST	5
#define ASN1_OP_I2D_PRE		6
#define ASN1_OP_I2D_POST	7

/* 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_ASN1_ALLOC_FUNCTIONS(stname) \
		IMPLEMENT_ASN1_ALLOC_FUNCTIONS_fname(stname, stname, stname)

#define IMPLEMENT_ASN1_ALLOC_FUNCTIONS_fname(stname, itname, fname) \
	stname *fname##_new(void) \
	{ \
		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 unsigned char **in, long len) \
	{ \
		return (stname *)ASN1_item_d2i((ASN1_VALUE **)a, in, len, ASN1_ITEM_rptr(itname));\
	} \
	int i2d_##fname(stname *a, unsigned char **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, unsigned char **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 unsigned char **in, long len) \
	{ \
		return (stname *)ASN1_item_d2i((ASN1_VALUE **)a, in, len, ASN1_ITEM_rptr(itname));\
	} \
	int i2d_##fname(const stname *a, unsigned char **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_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 */

DECLARE_ASN1_ITEM(ASN1_BOOLEAN)
DECLARE_ASN1_ITEM(ASN1_TBOOLEAN)
DECLARE_ASN1_ITEM(ASN1_FBOOLEAN)
DECLARE_ASN1_ITEM(ASN1_SEQUENCE)
DECLARE_ASN1_ITEM(CBIGNUM)
DECLARE_ASN1_ITEM(BIGNUM)
DECLARE_ASN1_ITEM(LONG)
DECLARE_ASN1_ITEM(ZLONG)

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 unsigned char **in, long len, const ASN1_TEMPLATE *tt);
int ASN1_item_ex_d2i(ASN1_VALUE **pval, const unsigned char **in, long len, const ASN1_ITEM *it,
				int tag, int aclass, char opt, ASN1_TLC *ctx);

int ASN1_item_ex_i2d(ASN1_VALUE **pval, unsigned char **out, const ASN1_ITEM *it, int tag, int aclass);
int ASN1_template_i2d(ASN1_VALUE **pval, unsigned char **out, const ASN1_TEMPLATE *tt);
void ASN1_primitive_free(ASN1_VALUE **pval, const ASN1_ITEM *it);

int asn1_ex_i2c(ASN1_VALUE **pval, unsigned char *cont, int *putype, const ASN1_ITEM *it);
int asn1_ex_c2i(ASN1_VALUE **pval, const unsigned char *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, unsigned char **out, ASN1_VALUE **pval, const ASN1_ITEM *it);
int asn1_enc_save(ASN1_VALUE **pval, const unsigned char *in, int inlen, const ASN1_ITEM *it);

#ifdef  __cplusplus
}
#endif
#endif