/* tasn_enc.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 "cryptlib.h"

#include <openssl/asn1.h>

#include <openssl/asn1t.h>

#include <openssl/objects.h>

static int asn1_i2d_ex_primitive(ASN1_VALUE **pval, unsigned char **out,

					const ASN1_ITEM *it,

					int tag, int aclass);

static int asn1_set_seq_out(STACK_OF(ASN1_VALUE) *sk, unsigned char **out,

					int skcontlen, const ASN1_ITEM *item,

					int do_sort, int iclass);

static int asn1_template_ex_i2d(ASN1_VALUE **pval, unsigned char **out,

					const ASN1_TEMPLATE *tt,

					int tag, int aclass);

static int asn1_item_flags_i2d(ASN1_VALUE *val, unsigned char **out,

					const ASN1_ITEM *it, int flags);

/* Top level i2d equivalents: the 'ndef' variant instructs the encoder

 * to use indefinite length constructed encoding, where appropriate

 */

EXPORT_C int ASN1_item_ndef_i2d(ASN1_VALUE *val, unsigned char **out,

						const ASN1_ITEM *it)

	{

	return asn1_item_flags_i2d(val, out, it, ASN1_TFLG_NDEF);

	}

EXPORT_C int ASN1_item_i2d(ASN1_VALUE *val, unsigned char **out, const ASN1_ITEM *it)

	{

	return asn1_item_flags_i2d(val, out, it, 0);

	}

/* Encode an ASN1 item, this is use by the

 * standard 'i2d' function. 'out' points to 

 * a buffer to output the data to.

 *

 * The new i2d has one additional feature. If the output

 * buffer is NULL (i.e. *out == NULL) then a buffer is

 * allocated and populated with the encoding.

 */

static int asn1_item_flags_i2d(ASN1_VALUE *val, unsigned char **out,

					const ASN1_ITEM *it, int flags)

	{

	if (out && !*out)

		{

		unsigned char *p, *buf;

		int len;

		len = ASN1_item_ex_i2d(&val, NULL, it, -1, flags);

		if (len <= 0)

			return len;

		buf = OPENSSL_malloc(len);

		if (!buf)

			return -1;

		p = buf;

		ASN1_item_ex_i2d(&val, &p, it, -1, flags);

		*out = buf;

		return len;

		}

	return ASN1_item_ex_i2d(&val, out, it, -1, flags);

	}

/* Encode an item, taking care of IMPLICIT tagging (if any).

 * This function performs the normal item handling: it can be

 * used in external types.

 */

EXPORT_C int ASN1_item_ex_i2d(ASN1_VALUE **pval, unsigned char **out,

			const ASN1_ITEM *it, int tag, int aclass)

	{

	const ASN1_TEMPLATE *tt = NULL;

	unsigned char *p = NULL;

	int i, seqcontlen, seqlen, ndef = 1;

	const ASN1_COMPAT_FUNCS *cf;

	const ASN1_EXTERN_FUNCS *ef;

	const ASN1_AUX *aux = it->funcs;

	ASN1_aux_cb *asn1_cb = 0;

	if ((it->itype != ASN1_ITYPE_PRIMITIVE) && !*pval)

		return 0;

	if (aux && aux->asn1_cb)

		 asn1_cb = aux->asn1_cb;

	switch(it->itype)

		{

		case ASN1_ITYPE_PRIMITIVE:

		if (it->templates)

			return asn1_template_ex_i2d(pval, out, it->templates,

								tag, aclass);

		return asn1_i2d_ex_primitive(pval, out, it, tag, aclass);

		break;

		case ASN1_ITYPE_MSTRING:

		return asn1_i2d_ex_primitive(pval, out, it, -1, aclass);

		case ASN1_ITYPE_CHOICE:

		if (asn1_cb && !asn1_cb(ASN1_OP_I2D_PRE, pval, it))

				return 0;

		i = asn1_get_choice_selector(pval, it);

		if ((i >= 0) && (i < it->tcount))

			{

			ASN1_VALUE **pchval;

			const ASN1_TEMPLATE *chtt;

			chtt = it->templates + i;

			pchval = asn1_get_field_ptr(pval, chtt);

			return asn1_template_ex_i2d(pchval, out, chtt,

								-1, aclass);

			}

		/* Fixme: error condition if selector out of range */

		if (asn1_cb && !asn1_cb(ASN1_OP_I2D_POST, pval, it))

				return 0;

		break;

		case ASN1_ITYPE_EXTERN:

		/* If new style i2d it does all the work */

		ef = it->funcs;

		return ef->asn1_ex_i2d(pval, out, it, tag, aclass);

		case ASN1_ITYPE_COMPAT:

		/* old style hackery... */

		cf = it->funcs;

		if (out)

			p = *out;

		i = cf->asn1_i2d(*pval, out);

		/* Fixup for IMPLICIT tag: note this messes up for tags > 30,

		 * but so did the old code. Tags > 30 are very rare anyway.

		 */

		if (out && (tag != -1))

			*p = aclass | tag | (*p & V_ASN1_CONSTRUCTED);

		return i;

		case ASN1_ITYPE_NDEF_SEQUENCE:

		/* Use indefinite length constructed if requested */

		if (aclass & ASN1_TFLG_NDEF) ndef = 2;

		/* fall through */

		case ASN1_ITYPE_SEQUENCE:

		i = asn1_enc_restore(&seqcontlen, out, pval, it);

		/* An error occurred */

		if (i < 0)

			return 0;

		/* We have a valid cached encoding... */

		if (i > 0)

			return seqcontlen;

		/* Otherwise carry on */

		seqcontlen = 0;

		/* If no IMPLICIT tagging set to SEQUENCE, UNIVERSAL */

		if (tag == -1)

			{

			tag = V_ASN1_SEQUENCE;

			/* Retain any other flags in aclass */

			aclass = (aclass & ~ASN1_TFLG_TAG_CLASS)

					| V_ASN1_UNIVERSAL;

			}

		if (asn1_cb && !asn1_cb(ASN1_OP_I2D_PRE, pval, it))

				return 0;

		/* First work out sequence content length */

		for (i = 0, tt = it->templates; i < it->tcount; tt++, i++)

			{

			const ASN1_TEMPLATE *seqtt;

			ASN1_VALUE **pseqval;

			seqtt = asn1_do_adb(pval, tt, 1);

			if (!seqtt)

				return 0;

			pseqval = asn1_get_field_ptr(pval, seqtt);

			/* FIXME: check for errors in enhanced version */

			seqcontlen += asn1_template_ex_i2d(pseqval, NULL, seqtt,

								-1, aclass);

			}

		seqlen = ASN1_object_size(ndef, seqcontlen, tag);

		if (!out)

			return seqlen;

		/* Output SEQUENCE header */

		ASN1_put_object(out, ndef, seqcontlen, tag, aclass);

		for (i = 0, tt = it->templates; i < it->tcount; tt++, i++)

			{

			const ASN1_TEMPLATE *seqtt;

			ASN1_VALUE **pseqval;

			seqtt = asn1_do_adb(pval, tt, 1);

			if (!seqtt)

				return 0;

			pseqval = asn1_get_field_ptr(pval, seqtt);

			/* FIXME: check for errors in enhanced version */

			asn1_template_ex_i2d(pseqval, out, seqtt, -1, aclass);

			}

		if (ndef == 2)

			ASN1_put_eoc(out);

		if (asn1_cb  && !asn1_cb(ASN1_OP_I2D_POST, pval, it))

				return 0;

		return seqlen;

		default:

		return 0;

		}

	return 0;

	}

EXPORT_C int ASN1_template_i2d(ASN1_VALUE **pval, unsigned char **out,

							const ASN1_TEMPLATE *tt)

	{

	return asn1_template_ex_i2d(pval, out, tt, -1, 0);

	}

static int asn1_template_ex_i2d(ASN1_VALUE **pval, unsigned char **out,

				const ASN1_TEMPLATE *tt, int tag, int iclass)

	{

	int i, ret, flags, ttag, tclass, ndef;

	flags = tt->flags;

	/* Work out tag and class to use: tagging may come

	 * either from the template or the arguments, not both

	 * because this would create ambiguity. Additionally

	 * the iclass argument may contain some additional flags

	 * which should be noted and passed down to other levels.

	 */

	if (flags & ASN1_TFLG_TAG_MASK)

		{

		/* Error if argument and template tagging */

		if (tag != -1)

			/* FIXME: error code here */

			return -1;

		/* Get tagging from template */

		ttag = tt->tag;

		tclass = flags & ASN1_TFLG_TAG_CLASS;

		}

	else if (tag != -1)

		{

		/* No template tagging, get from arguments */

		ttag = tag;

		tclass = iclass & ASN1_TFLG_TAG_CLASS;

		}

	else

		{

		ttag = -1;

		tclass = 0;

		}

	/* 

	 * Remove any class mask from iflag.

	 */

	iclass &= ~ASN1_TFLG_TAG_CLASS;

	/* At this point 'ttag' contains the outer tag to use,

	 * 'tclass' is the class and iclass is any flags passed

	 * to this function.

	 */

	/* if template and arguments require ndef, use it */

	if ((flags & ASN1_TFLG_NDEF) && (iclass & ASN1_TFLG_NDEF))

		ndef = 2;

	else ndef = 1;

	if (flags & ASN1_TFLG_SK_MASK)

		{

		/* SET OF, SEQUENCE OF */

		STACK_OF(ASN1_VALUE) *sk = (STACK_OF(ASN1_VALUE) *)*pval;

		int isset, sktag, skaclass;

		int skcontlen, sklen;

		ASN1_VALUE *skitem;

		if (!*pval)

			return 0;

		if (flags & ASN1_TFLG_SET_OF)

			{

			isset = 1;

			/* 2 means we reorder */

			if (flags & ASN1_TFLG_SEQUENCE_OF)

				isset = 2;

			}

		else isset = 0;

		/* Work out inner tag value: if EXPLICIT

		 * or no tagging use underlying type.

		 */

		if ((ttag != -1) && !(flags & ASN1_TFLG_EXPTAG))

			{

			sktag = ttag;

			skaclass = tclass;

			}

		else

			{

			skaclass = V_ASN1_UNIVERSAL;

			if (isset)

				sktag = V_ASN1_SET;

			else sktag = V_ASN1_SEQUENCE;

			}

		/* Determine total length of items */

		skcontlen = 0;

		for (i = 0; i < sk_ASN1_VALUE_num(sk); i++)

			{

			skitem = sk_ASN1_VALUE_value(sk, i);

			skcontlen += ASN1_item_ex_i2d(&skitem, NULL,

						ASN1_ITEM_ptr(tt->item),

							-1, iclass);

			}

		sklen = ASN1_object_size(ndef, skcontlen, sktag);

		/* If EXPLICIT need length of surrounding tag */

		if (flags & ASN1_TFLG_EXPTAG)

			ret = ASN1_object_size(ndef, sklen, ttag);

		else ret = sklen;

		if (!out)

			return ret;

		/* Now encode this lot... */

		/* EXPLICIT tag */

		if (flags & ASN1_TFLG_EXPTAG)

			ASN1_put_object(out, ndef, sklen, ttag, tclass);

		/* SET or SEQUENCE and IMPLICIT tag */

		ASN1_put_object(out, ndef, skcontlen, sktag, skaclass);

		/* And the stuff itself */

		asn1_set_seq_out(sk, out, skcontlen, ASN1_ITEM_ptr(tt->item),

								isset, iclass);

		if (ndef == 2)

			{

			ASN1_put_eoc(out);

			if (flags & ASN1_TFLG_EXPTAG)

				ASN1_put_eoc(out);

			}

		return ret;

		}

	if (flags & ASN1_TFLG_EXPTAG)

		{

		/* EXPLICIT tagging */

		/* Find length of tagged item */

		i = ASN1_item_ex_i2d(pval, NULL, ASN1_ITEM_ptr(tt->item),

								-1, iclass);

		if (!i)

			return 0;

		/* Find length of EXPLICIT tag */

		ret = ASN1_object_size(ndef, i, ttag);

		if (out)

			{

			/* Output tag and item */

			ASN1_put_object(out, ndef, i, ttag, tclass);

			ASN1_item_ex_i2d(pval, out, ASN1_ITEM_ptr(tt->item),

								-1, iclass);

			if (ndef == 2)

				ASN1_put_eoc(out);

			}

		return ret;

		}

	/* Either normal or IMPLICIT tagging: combine class and flags */

	return ASN1_item_ex_i2d(pval, out, ASN1_ITEM_ptr(tt->item),

						ttag, tclass | iclass);

}

/* Temporary structure used to hold DER encoding of items for SET OF */

typedef	struct {

	unsigned char *data;

	int length;

	ASN1_VALUE *field;

} DER_ENC;

static int der_cmp(const void *a, const void *b)

	{

	const DER_ENC *d1 = a, *d2 = b;

	int cmplen, i;

	cmplen = (d1->length < d2->length) ? d1->length : d2->length;

	i = memcmp(d1->data, d2->data, cmplen);

	if (i)

		return i;

	return d1->length - d2->length;

	}

/* Output the content octets of SET OF or SEQUENCE OF */

static int asn1_set_seq_out(STACK_OF(ASN1_VALUE) *sk, unsigned char **out,

					int skcontlen, const ASN1_ITEM *item,

					int do_sort, int iclass)

	{

	int i;

	ASN1_VALUE *skitem;

	unsigned char *tmpdat = NULL, *p = NULL;

	DER_ENC *derlst = NULL, *tder;

	if (do_sort)

		 {

		/* Don't need to sort less than 2 items */

		if (sk_ASN1_VALUE_num(sk) < 2)

			do_sort = 0;

		else

			{

			derlst = OPENSSL_malloc(sk_ASN1_VALUE_num(sk)

						* sizeof(*derlst));

			tmpdat = OPENSSL_malloc(skcontlen);

			if (!derlst || !tmpdat)

				return 0;

			}

		}

	/* If not sorting just output each item */

	if (!do_sort)

		{

		for (i = 0; i < sk_ASN1_VALUE_num(sk); i++)

			{

			skitem = sk_ASN1_VALUE_value(sk, i);

			ASN1_item_ex_i2d(&skitem, out, item, -1, iclass);

			}

		return 1;

		}

	p = tmpdat;

	/* Doing sort: build up a list of each member's DER encoding */

	for (i = 0, tder = derlst; i < sk_ASN1_VALUE_num(sk); i++, tder++)

		{

		skitem = sk_ASN1_VALUE_value(sk, i);

		tder->data = p;

		tder->length = ASN1_item_ex_i2d(&skitem, &p, item, -1, iclass);

		tder->field = skitem;

		}

	/* Now sort them */

	qsort(derlst, sk_ASN1_VALUE_num(sk), sizeof(*derlst), der_cmp);

	/* Output sorted DER encoding */	

	p = *out;

	for (i = 0, tder = derlst; i < sk_ASN1_VALUE_num(sk); i++, tder++)

		{

		memcpy(p, tder->data, tder->length);

		p += tder->length;

		}

	*out = p;

	/* If do_sort is 2 then reorder the STACK */

	if (do_sort == 2)

		{

		for (i = 0, tder = derlst; i < sk_ASN1_VALUE_num(sk);

							i++, tder++)

			(void)sk_ASN1_VALUE_set(sk, i, tder->field);

		}

	OPENSSL_free(derlst);

	OPENSSL_free(tmpdat);

	return 1;

	}

static int asn1_i2d_ex_primitive(ASN1_VALUE **pval, unsigned char **out,

				const ASN1_ITEM *it, int tag, int aclass)

	{

	int len;

	int utype;

	int usetag;

	int ndef = 0;

	utype = it->utype;

	/* Get length of content octets and maybe find

	 * out the underlying type.

	 */

	len = asn1_ex_i2c(pval, NULL, &utype, it);

	/* If SEQUENCE, SET or OTHER then header is

	 * included in pseudo content octets so don't

	 * include tag+length. We need to check here

	 * because the call to asn1_ex_i2c() could change

	 * utype.

	 */

	if ((utype == V_ASN1_SEQUENCE) || (utype == V_ASN1_SET) ||

	   (utype == V_ASN1_OTHER))

		usetag = 0;