/* tasn_utl.c */

/* Written by Dr Stephen N Henson (shenson@bigfoot.com) for the OpenSSL

 * project 2000.

 */

/* ====================================================================

 * Copyright (c) 2000-2004 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).

 *

 */

#include <stddef.h>

#include <string.h>

#include <openssl/asn1.h>

#include <openssl/asn1t.h>

#include <openssl/objects.h>

#include <openssl/err.h>

/* Utility functions for manipulating fields and offsets */

/* Add 'offset' to 'addr' */

#define offset2ptr(addr, offset) (void *)(((char *) addr) + offset)

/* Given an ASN1_ITEM CHOICE type return

 * the selector value

 */

EXPORT_C int asn1_get_choice_selector(ASN1_VALUE **pval, const ASN1_ITEM *it)

	{

	int *sel = offset2ptr(*pval, it->utype);

	return *sel;

	}

/* Given an ASN1_ITEM CHOICE type set

 * the selector value, return old value.

 */

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

	{	

	int *sel, ret;

	sel = offset2ptr(*pval, it->utype);

	ret = *sel;

	*sel = value;

	return ret;

	}

/* Do reference counting. The value 'op' decides what to do. 

 * if it is +1 then the count is incremented. If op is 0 count is

 * set to 1. If op is -1 count is decremented and the return value

 * is the current refrence count or 0 if no reference count exists.

 */

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

	{

	const ASN1_AUX *aux;

	int *lck, ret;

	if ((it->itype != ASN1_ITYPE_SEQUENCE)

	   && (it->itype != ASN1_ITYPE_NDEF_SEQUENCE))

		return 0;

	aux = it->funcs;

	if (!aux || !(aux->flags & ASN1_AFLG_REFCOUNT))

		return 0;

	lck = offset2ptr(*pval, aux->ref_offset);

	if (op == 0)

		{

		*lck = 1;

		return 1;

		}

	ret = CRYPTO_add(lck, op, aux->ref_lock);

#ifdef REF_PRINT

	fprintf(stderr, "%s: Reference Count: %d\n", it->sname, *lck);

#endif

#ifdef REF_CHECK

	if (ret < 0) 

		fprintf(stderr, "%s, bad reference count\n", it->sname);

#endif

	return ret;

	}

static ASN1_ENCODING *asn1_get_enc_ptr(ASN1_VALUE **pval, const ASN1_ITEM *it)

	{

	const ASN1_AUX *aux;

	if (!pval || !*pval)

		return NULL;

	aux = it->funcs;

	if (!aux || !(aux->flags & ASN1_AFLG_ENCODING))

		return NULL;

	return offset2ptr(*pval, aux->enc_offset);

	}

EXPORT_C void asn1_enc_init(ASN1_VALUE **pval, const ASN1_ITEM *it)

	{

	ASN1_ENCODING *enc;

	enc = asn1_get_enc_ptr(pval, it);

	if (enc)

		{

		enc->enc = NULL;

		enc->len = 0;

		enc->modified = 1;

		}

	}

EXPORT_C void asn1_enc_free(ASN1_VALUE **pval, const ASN1_ITEM *it)

	{

	ASN1_ENCODING *enc;

	enc = asn1_get_enc_ptr(pval, it);

	if (enc)

		{

		if (enc->enc)

			OPENSSL_free(enc->enc);

		enc->enc = NULL;

		enc->len = 0;

		enc->modified = 1;

		}

	}

EXPORT_C int asn1_enc_save(ASN1_VALUE **pval, const unsigned char *in, int inlen,

							 const ASN1_ITEM *it)

	{

	ASN1_ENCODING *enc;

	enc = asn1_get_enc_ptr(pval, it);

	if (!enc)

		return 1;

	if (enc->enc)

		OPENSSL_free(enc->enc);

	enc->enc = OPENSSL_malloc(inlen);

	if (!enc->enc)

		return 0;

	memcpy(enc->enc, in, inlen);

	enc->len = inlen;

	enc->modified = 0;

	return 1;

	}

EXPORT_C int asn1_enc_restore(int *len, unsigned char **out, ASN1_VALUE **pval,

							const ASN1_ITEM *it)

	{

	ASN1_ENCODING *enc;

	enc = asn1_get_enc_ptr(pval, it);

	if (!enc || enc->modified)

		return 0;

	if (out)

		{

		memcpy(*out, enc->enc, enc->len);

		*out += enc->len;

		}

	if (len)

		*len = enc->len;

	return 1;

	}

/* Given an ASN1_TEMPLATE get a pointer to a field */

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

	{

	ASN1_VALUE **pvaltmp;

	if (tt->flags & ASN1_TFLG_COMBINE)

		return pval;

	pvaltmp = offset2ptr(*pval, tt->offset);

	/* NOTE for BOOLEAN types the field is just a plain

 	 * int so we can't return int **, so settle for

	 * (int *).

	 */

	return pvaltmp;

	}

/* Handle ANY DEFINED BY template, find the selector, look up

 * the relevant ASN1_TEMPLATE in the table and return it.

 */

EXPORT_C const ASN1_TEMPLATE *asn1_do_adb(ASN1_VALUE **pval, const ASN1_TEMPLATE *tt,

								int nullerr)

	{

	const ASN1_ADB *adb;

	const ASN1_ADB_TABLE *atbl;

	long selector;

	ASN1_VALUE **sfld;

	int i;

	if (!(tt->flags & ASN1_TFLG_ADB_MASK))

		return tt;

	/* Else ANY DEFINED BY ... get the table */

	adb = ASN1_ADB_ptr(tt->item);

	/* Get the selector field */

	sfld = offset2ptr(*pval, adb->offset);

	/* Check if NULL */

	if (!sfld)

		{

		if (!adb->null_tt)

			goto err;

		return adb->null_tt;

		}

	/* Convert type to a long:

	 * NB: don't check for NID_undef here because it

	 * might be a legitimate value in the table

	 */

	if (tt->flags & ASN1_TFLG_ADB_OID) 

		selector = OBJ_obj2nid((ASN1_OBJECT *)*sfld);

	else 

		selector = ASN1_INTEGER_get((ASN1_INTEGER *)*sfld);

	/* Try to find matching entry in table

	 * Maybe should check application types first to

	 * allow application override? Might also be useful

	 * to have a flag which indicates table is sorted and

	 * we can do a binary search. For now stick to a

	 * linear search.

	 */

	for (atbl = adb->tbl, i = 0; i < adb->tblcount; i++, atbl++)

		if (atbl->value == selector)

			return &atbl->tt;

	/* FIXME: need to search application table too */

	/* No match, return default type */

	if (!adb->default_tt)

		goto err;		

	return adb->default_tt;

	err:

	/* FIXME: should log the value or OID of unsupported type */

	if (nullerr)

		ASN1err(ASN1_F_ASN1_DO_ADB,

			ASN1_R_UNSUPPORTED_ANY_DEFINED_BY_TYPE);

	return NULL;

	}