crypto/asn1/tasn_dec.c

/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
 * All rights reserved.
 *
 * This package is an SSL implementation written
 * by Eric Young (eay@cryptsoft.com).
 * The implementation was written so as to conform with Netscapes SSL.
 *
 * This library is free for commercial and non-commercial use as long as
 * the following conditions are aheared to.  The following conditions
 * apply to all code found in this distribution, be it the RC4, RSA,
 * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
 * included with this distribution is covered by the same copyright terms
 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
 *
 * Copyright remains Eric Young's, and as such any Copyright notices in
 * the code are not to be removed.
 * If this package is used in a product, Eric Young should be given attribution
 * as the author of the parts of the library used.
 * This can be in the form of a textual message at program startup or
 * in documentation (online or textual) provided with the package.
 *
 * 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 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 acknowledgement:
 *    "This product includes cryptographic software written by
 *     Eric Young (eay@cryptsoft.com)"
 *    The word 'cryptographic' can be left out if the rouines from the library
 *    being used are not cryptographic related :-).
 * 4. If you include any Windows specific code (or a derivative thereof) from
 *    the apps directory (application code) you must include an acknowledgement:
 *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
 *
 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
 * ANY EXPRESS 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 AUTHOR OR 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.
 *
 * The licence and distribution terms for any publically available version or
 * derivative of this code cannot be changed.  i.e. this code cannot simply be
 * copied and put under another distribution licence
 * [including the GNU Public Licence.] */

#include <openssl/asn1.h>

#include <string.h>

#include <openssl/asn1t.h>
#include <openssl/buf.h>
#include <openssl/err.h>
#include <openssl/mem.h>


static int asn1_check_eoc(const unsigned char **in, long len);
static int asn1_find_end(const unsigned char **in, long len, char inf);

static int asn1_collect(BUF_MEM *buf, const unsigned char **in, long len,
			char inf, int tag, int aclass, int depth);

static int collect_data(BUF_MEM *buf, const unsigned char **p, long plen);

static int asn1_check_tlen(long *olen, int *otag, unsigned char *oclass,
				char *inf, char *cst,
				const unsigned char **in, long len,
				int exptag, int expclass, char opt,
				ASN1_TLC *ctx);

static int asn1_template_ex_d2i(ASN1_VALUE **pval,
				const unsigned char **in, long len,
				const ASN1_TEMPLATE *tt, char opt,
				ASN1_TLC *ctx);
static int asn1_template_noexp_d2i(ASN1_VALUE **val,
				const unsigned char **in, long len,
				const ASN1_TEMPLATE *tt, char opt,
				ASN1_TLC *ctx);
static int asn1_d2i_ex_primitive(ASN1_VALUE **pval,
				const unsigned char **in, long len,
				const ASN1_ITEM *it,
				int tag, int aclass, char opt, ASN1_TLC *ctx);

/* Table to convert tags to bit values, used for MSTRING type */
static const unsigned long tag2bit[32] = {
0,	0,	0,	B_ASN1_BIT_STRING,	/* tags  0 -  3 */
B_ASN1_OCTET_STRING,	0,	0,		B_ASN1_UNKNOWN,/* tags  4- 7 */
B_ASN1_UNKNOWN,	B_ASN1_UNKNOWN,	B_ASN1_UNKNOWN,	B_ASN1_UNKNOWN,/* tags  8-11 */
B_ASN1_UTF8STRING,B_ASN1_UNKNOWN,B_ASN1_UNKNOWN,B_ASN1_UNKNOWN,/* tags 12-15 */
B_ASN1_SEQUENCE,0,B_ASN1_NUMERICSTRING,B_ASN1_PRINTABLESTRING, /* tags 16-19 */
B_ASN1_T61STRING,B_ASN1_VIDEOTEXSTRING,B_ASN1_IA5STRING,       /* tags 20-22 */
B_ASN1_UTCTIME, B_ASN1_GENERALIZEDTIME,			       /* tags 23-24 */	
B_ASN1_GRAPHICSTRING,B_ASN1_ISO64STRING,B_ASN1_GENERALSTRING,  /* tags 25-27 */
B_ASN1_UNIVERSALSTRING,B_ASN1_UNKNOWN,B_ASN1_BMPSTRING,B_ASN1_UNKNOWN, /* tags 28-31 */
	};

unsigned long ASN1_tag2bit(int tag)
	{
	if ((tag < 0) || (tag > 30)) return 0;
	return tag2bit[tag];
	}

/* Macro to initialize and invalidate the cache */

#define asn1_tlc_clear(c)	if (c) (c)->valid = 0
/* Version to avoid compiler warning about 'c' always non-NULL */
#define asn1_tlc_clear_nc(c)	(c)->valid = 0

/* Decode an ASN1 item, this currently behaves just 
 * like a standard 'd2i' function. 'in' points to 
 * a buffer to read the data from, in future we will
 * have more advanced versions that can input data
 * a piece at a time and this will simply be a special
 * case.
 */

ASN1_VALUE *ASN1_item_d2i(ASN1_VALUE **pval,
		const unsigned char **in, long len, const ASN1_ITEM *it)
	{
	ASN1_TLC c;
	ASN1_VALUE *ptmpval = NULL;
	if (!pval)
		pval = &ptmpval;
	asn1_tlc_clear_nc(&c);
	if (ASN1_item_ex_d2i(pval, in, len, it, -1, 0, 0, &c) > 0) 
		return *pval;
	return NULL;
	}

int ASN1_template_d2i(ASN1_VALUE **pval,
		const unsigned char **in, long len, const ASN1_TEMPLATE *tt)
	{
	ASN1_TLC c;
	asn1_tlc_clear_nc(&c);
	return asn1_template_ex_d2i(pval, in, len, tt, 0, &c);
	}


/* Decode an item, taking care of IMPLICIT tagging, if any.
 * If 'opt' set and tag mismatch return -1 to handle OPTIONAL
 */

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)
	{
	const ASN1_TEMPLATE *tt, *errtt = NULL;
	const ASN1_COMPAT_FUNCS *cf;
	const ASN1_EXTERN_FUNCS *ef;
	const ASN1_AUX *aux = it->funcs;
	ASN1_aux_cb *asn1_cb;
	const unsigned char *p = NULL, *q;
	unsigned char *wp=NULL;	/* BIG FAT WARNING!  BREAKS CONST WHERE USED */
	unsigned char imphack = 0, oclass;
	char seq_eoc, seq_nolen, cst, isopt;
	long tmplen;
	int i;
	int otag;
	int ret = 0;
	ASN1_VALUE **pchptr, *ptmpval;
	if (!pval)
		return 0;
	if (aux && aux->asn1_cb)
		asn1_cb = aux->asn1_cb;
	else asn1_cb = 0;

	switch(it->itype)
		{
		case ASN1_ITYPE_PRIMITIVE:
		if (it->templates)
			{
			/* tagging or OPTIONAL is currently illegal on an item
			 * template because the flags can't get passed down.
			 * In practice this isn't a problem: we include the
			 * relevant flags from the item template in the
			 * template itself.
			 */
			if ((tag != -1) || opt)
				{
				OPENSSL_PUT_ERROR(ASN1, ASN1_item_ex_d2i,  ASN1_R_ILLEGAL_OPTIONS_ON_ITEM_TEMPLATE);
				goto err;
				}
			return asn1_template_ex_d2i(pval, in, len,
					it->templates, opt, ctx);
		}
		return asn1_d2i_ex_primitive(pval, in, len, it,
						tag, aclass, opt, ctx);
		break;

		case ASN1_ITYPE_MSTRING:
		p = *in;
		/* Just read in tag and class */
		ret = asn1_check_tlen(NULL, &otag, &oclass, NULL, NULL,
						&p, len, -1, 0, 1, ctx);
		if (!ret)
			{
			OPENSSL_PUT_ERROR(ASN1, ASN1_item_ex_d2i,  ASN1_R_NESTED_ASN1_ERROR);
			goto err;
			}

		/* Must be UNIVERSAL class */
		if (oclass != V_ASN1_UNIVERSAL)
			{
			/* If OPTIONAL, assume this is OK */
			if (opt) return -1;
			OPENSSL_PUT_ERROR(ASN1, ASN1_item_ex_d2i,  ASN1_R_MSTRING_NOT_UNIVERSAL);
			goto err;
			}
		/* Check tag matches bit map */
		if (!(ASN1_tag2bit(otag) & it->utype))
			{
			/* If OPTIONAL, assume this is OK */
			if (opt)
				return -1;
			OPENSSL_PUT_ERROR(ASN1, ASN1_item_ex_d2i,  ASN1_R_MSTRING_WRONG_TAG);
			goto err;
			}
		return asn1_d2i_ex_primitive(pval, in, len,
						it, otag, 0, 0, ctx);

		case ASN1_ITYPE_EXTERN:
		/* Use new style d2i */
		ef = it->funcs;
		return ef->asn1_ex_d2i(pval, in, len,
						it, tag, aclass, opt, ctx);

		case ASN1_ITYPE_COMPAT:
		/* we must resort to old style evil hackery */
		cf = it->funcs;

		/* If OPTIONAL see if it is there */
		if (opt)
			{
			int exptag;
			p = *in;
			if (tag == -1)
				exptag = it->utype;
			else exptag = tag;
			/* Don't care about anything other than presence
			 * of expected tag */

			ret = asn1_check_tlen(NULL, NULL, NULL, NULL, NULL,
					&p, len, exptag, aclass, 1, ctx);
			if (!ret)
				{
				OPENSSL_PUT_ERROR(ASN1, ASN1_item_ex_d2i,  ASN1_R_NESTED_ASN1_ERROR);
				goto err;
				}
			if (ret == -1)
				return -1;
			}

		/* This is the old style evil hack IMPLICIT handling:
		 * since the underlying code is expecting a tag and
		 * class other than the one present we change the
		 * buffer temporarily then change it back afterwards.
		 * This doesn't and never did work for tags > 30.
		 *
		 * Yes this is *horrible* but it is only needed for
		 * old style d2i which will hopefully not be around
		 * for much longer.
		 * FIXME: should copy the buffer then modify it so
		 * the input buffer can be const: we should *always*
		 * copy because the old style d2i might modify the
		 * buffer.
		 */

		if (tag != -1)
			{
			wp = *(unsigned char **)in;
			imphack = *wp;
			if (p == NULL)
				{
				OPENSSL_PUT_ERROR(ASN1, ASN1_item_ex_d2i,  ASN1_R_NESTED_ASN1_ERROR);
				goto err;
				}
			*wp = (unsigned char)((*p & V_ASN1_CONSTRUCTED)
								| it->utype);
			}

		ptmpval = cf->asn1_d2i(pval, in, len);

		if (tag != -1)
			*wp = imphack;

		if (ptmpval)
			return 1;

		OPENSSL_PUT_ERROR(ASN1, ASN1_item_ex_d2i,  ASN1_R_NESTED_ASN1_ERROR);
		goto err;


		case ASN1_ITYPE_CHOICE:
		if (asn1_cb && !asn1_cb(ASN1_OP_D2I_PRE, pval, it, NULL))
				goto auxerr;

		/* Allocate structure */
		if (!*pval && !ASN1_item_ex_new(pval, it))
			{
			OPENSSL_PUT_ERROR(ASN1, ASN1_item_ex_d2i,  ASN1_R_NESTED_ASN1_ERROR);
			goto err;
			}
		/* CHOICE type, try each possibility in turn */
		p = *in;
		for (i = 0, tt=it->templates; i < it->tcount; i++, tt++)
			{
			pchptr = asn1_get_field_ptr(pval, tt);
			/* We mark field as OPTIONAL so its absence
			 * can be recognised.
			 */
			ret = asn1_template_ex_d2i(pchptr, &p, len, tt, 1, ctx);
			/* If field not present, try the next one */
			if (ret == -1)
				continue;
			/* If positive return, read OK, break loop */
			if (ret > 0)
				break;
			/* Otherwise must be an ASN1 parsing error */
			errtt = tt;
			OPENSSL_PUT_ERROR(ASN1, ASN1_item_ex_d2i,  ASN1_R_NESTED_ASN1_ERROR);
			goto err;
			}

		/* Did we fall off the end without reading anything? */
		if (i == it->tcount)
			{
			/* If OPTIONAL, this is OK */
			if (opt)
				{
				/* Free and zero it */
				ASN1_item_ex_free(pval, it);
				return -1;
				}
			OPENSSL_PUT_ERROR(ASN1, ASN1_item_ex_d2i,  ASN1_R_NO_MATCHING_CHOICE_TYPE);
			goto err;
			}

		asn1_set_choice_selector(pval, i, it);
		*in = p;
		if (asn1_cb && !asn1_cb(ASN1_OP_D2I_POST, pval, it, NULL))
				goto auxerr;
		return 1;

		case ASN1_ITYPE_NDEF_SEQUENCE:
		case ASN1_ITYPE_SEQUENCE:
		p = *in;
		tmplen = len;

		/* If no IMPLICIT tagging set to SEQUENCE, UNIVERSAL */
		if (tag == -1)
			{
			tag = V_ASN1_SEQUENCE;
			aclass = V_ASN1_UNIVERSAL;
			}
		/* Get SEQUENCE length and update len, p */
		ret = asn1_check_tlen(&len, NULL, NULL, &seq_eoc, &cst,
					&p, len, tag, aclass, opt, ctx);
		if (!ret)
			{
			OPENSSL_PUT_ERROR(ASN1, ASN1_item_ex_d2i,  ASN1_R_NESTED_ASN1_ERROR);
			goto err;
			}
		else if (ret == -1)
			return -1;
		if (aux && (aux->flags & ASN1_AFLG_BROKEN))
			{
			len = tmplen - (p - *in);
			seq_nolen = 1;
			}
		/* If indefinite we don't do a length check */
		else seq_nolen = seq_eoc;
		if (!cst)
			{
			OPENSSL_PUT_ERROR(ASN1, ASN1_item_ex_d2i,  ASN1_R_SEQUENCE_NOT_CONSTRUCTED);
			goto err;
			}

		if (!*pval && !ASN1_item_ex_new(pval, it))
			{
			OPENSSL_PUT_ERROR(ASN1, ASN1_item_ex_d2i,  ASN1_R_NESTED_ASN1_ERROR);
			goto err;
			}

		if (asn1_cb && !asn1_cb(ASN1_OP_D2I_PRE, pval, it, NULL))
				goto auxerr;

		/* Get each field entry */
		for (i = 0, tt = it->templates; i < it->tcount; i++, tt++)
			{
			const ASN1_TEMPLATE *seqtt;
			ASN1_VALUE **pseqval;
			seqtt = asn1_do_adb(pval, tt, 1);
			if (!seqtt)
				goto err;
			pseqval = asn1_get_field_ptr(pval, seqtt);
			/* Have we ran out of data? */
			if (!len)
				break;
			q = p;
			if (asn1_check_eoc(&p, len))
				{
				if (!seq_eoc)
					{
					OPENSSL_PUT_ERROR(ASN1, ASN1_item_ex_d2i,  ASN1_R_UNEXPECTED_EOC);
					goto err;
					}
				len -= p - q;
				seq_eoc = 0;
				q = p;
				break;
				}
			/* This determines the OPTIONAL flag value. The field
			 * cannot be omitted if it is the last of a SEQUENCE
			 * and there is still data to be read. This isn't
			 * strictly necessary but it increases efficiency in
			 * some cases.
			 */
			if (i == (it->tcount - 1))
				isopt = 0;
			else isopt = (char)(seqtt->flags & ASN1_TFLG_OPTIONAL);
			/* attempt to read in field, allowing each to be
			 * OPTIONAL */

			ret = asn1_template_ex_d2i(pseqval, &p, len,
							seqtt, isopt, ctx);
			if (!ret)
				{
				errtt = seqtt;
				goto err;
				}
			else if (ret == -1)
				{
				/* OPTIONAL component absent.
				 * Free and zero the field.
				 */
				ASN1_template_free(pseqval, seqtt);
				continue;
				}
			/* Update length */
			len -= p - q;
			}

		/* Check for EOC if expecting one */
		if (seq_eoc && !asn1_check_eoc(&p, len))
			{
			OPENSSL_PUT_ERROR(ASN1, ASN1_item_ex_d2i,  ASN1_R_MISSING_EOC);
			goto err;
			}
		/* Check all data read */
		if (!seq_nolen && len)
			{
			OPENSSL_PUT_ERROR(ASN1, ASN1_item_ex_d2i,  ASN1_R_SEQUENCE_LENGTH_MISMATCH);
			goto err;
			}

		/* If we get here we've got no more data in the SEQUENCE,
		 * however we may not have read all fields so check all
		 * remaining are OPTIONAL and clear any that are.
		 */
		for (; i < it->tcount; tt++, i++)
			{
			const ASN1_TEMPLATE *seqtt;
			seqtt = asn1_do_adb(pval, tt, 1);
			if (!seqtt)
				goto err;
			if (seqtt->flags & ASN1_TFLG_OPTIONAL)
				{
				ASN1_VALUE **pseqval;
				pseqval = asn1_get_field_ptr(pval, seqtt);
				ASN1_template_free(pseqval, seqtt);
				}
			else
				{
				errtt = seqtt;
				OPENSSL_PUT_ERROR(ASN1, ASN1_item_ex_d2i,  ASN1_R_FIELD_MISSING);
				goto err;
				}
			}
		/* Save encoding */
		if (!asn1_enc_save(pval, *in, p - *in, it))
			goto auxerr;
		*in = p;
		if (asn1_cb && !asn1_cb(ASN1_OP_D2I_POST, pval, it, NULL))
				goto auxerr;
		return 1;

		default:
		return 0;
		}
	auxerr:
	OPENSSL_PUT_ERROR(ASN1, ASN1_item_ex_d2i,  ASN1_R_AUX_ERROR);
	err:
	ASN1_item_ex_free(pval, it);
	if (errtt)
		ERR_add_error_data(4, "Field=", errtt->field_name,
					", Type=", it->sname);
	else
		ERR_add_error_data(2, "Type=", it->sname);
	return 0;
	}

/* Templates are handled with two separate functions.
 * One handles any EXPLICIT tag and the other handles the rest.
 */

static int asn1_template_ex_d2i(ASN1_VALUE **val,
				const unsigned char **in, long inlen,
				const ASN1_TEMPLATE *tt, char opt,
							ASN1_TLC *ctx)
	{
	int flags, aclass;
	int ret;
	long len;
	const unsigned char *p, *q;
	char exp_eoc;
	if (!val)
		return 0;
	flags = tt->flags;
	aclass = flags & ASN1_TFLG_TAG_CLASS;

	p = *in;

	/* Check if EXPLICIT tag expected */
	if (flags & ASN1_TFLG_EXPTAG)
		{
		char cst;
		/* Need to work out amount of data available to the inner
		 * content and where it starts: so read in EXPLICIT header to
		 * get the info.
		 */
		ret = asn1_check_tlen(&len, NULL, NULL, &exp_eoc, &cst,
					&p, inlen, tt->tag, aclass, opt, ctx);
		q = p;
		if (!ret)
			{
			OPENSSL_PUT_ERROR(ASN1, asn1_template_ex_d2i,  ASN1_R_NESTED_ASN1_ERROR);
			return 0;
			}
		else if (ret == -1)
			return -1;
		if (!cst)
			{
			OPENSSL_PUT_ERROR(ASN1, asn1_template_ex_d2i,  ASN1_R_EXPLICIT_TAG_NOT_CONSTRUCTED);
			return 0;
			}
		/* We've found the field so it can't be OPTIONAL now */
		ret = asn1_template_noexp_d2i(val, &p, len, tt, 0, ctx);
		if (!ret)
			{
			OPENSSL_PUT_ERROR(ASN1, asn1_template_ex_d2i,  ASN1_R_NESTED_ASN1_ERROR);
			return 0;
			}
		/* We read the field in OK so update length */
		len -= p - q;
		if (exp_eoc)
			{
			/* If NDEF we must have an EOC here */
			if (!asn1_check_eoc(&p, len))
				{
				OPENSSL_PUT_ERROR(ASN1, asn1_template_ex_d2i,  ASN1_R_MISSING_EOC);
				goto err;
				}
			}
		else
			{
			/* Otherwise we must hit the EXPLICIT tag end or its
			 * an error */
			if (len)
				{
				OPENSSL_PUT_ERROR(ASN1, asn1_template_ex_d2i,  ASN1_R_EXPLICIT_LENGTH_MISMATCH);
				goto err;
				}
			}
		}
		else 
			return asn1_template_noexp_d2i(val, in, inlen,
								tt, opt, ctx);

	*in = p;
	return 1;

	err:
	ASN1_template_free(val, tt);
	return 0;
	}

static int asn1_template_noexp_d2i(ASN1_VALUE **val,
				const unsigned char **in, long len,
				const ASN1_TEMPLATE *tt, char opt,
				ASN1_TLC *ctx)
	{
	int flags, aclass;
	int ret;
	const unsigned char *p;
	if (!val)
		return 0;
	flags = tt->flags;
	aclass = flags & ASN1_TFLG_TAG_CLASS;

	p = *in;

	if (flags & ASN1_TFLG_SK_MASK)
		{
		/* SET OF, SEQUENCE OF */
		int sktag, skaclass;
		char sk_eoc;
		/* First work out expected inner tag value */
		if (flags & ASN1_TFLG_IMPTAG)
			{
			sktag = tt->tag;
			skaclass = aclass;
			}
		else
			{
			skaclass = V_ASN1_UNIVERSAL;
			if (flags & ASN1_TFLG_SET_OF)
				sktag = V_ASN1_SET;
			else
				sktag = V_ASN1_SEQUENCE;
			}
		/* Get the tag */
		ret = asn1_check_tlen(&len, NULL, NULL, &sk_eoc, NULL,
					&p, len, sktag, skaclass, opt, ctx);
		if (!ret)
			{
			OPENSSL_PUT_ERROR(ASN1, asn1_template_noexp_d2i,  ASN1_R_NESTED_ASN1_ERROR);
			return 0;
			}
		else if (ret == -1)
			return -1;
		if (!*val)
			*val = (ASN1_VALUE *)sk_new_null();
		else
			{
			/* We've got a valid STACK: free up any items present */
			STACK_OF(ASN1_VALUE) *sktmp
			    = (STACK_OF(ASN1_VALUE) *)*val;
			ASN1_VALUE *vtmp;
			while(sk_ASN1_VALUE_num(sktmp) > 0)
				{
				vtmp = sk_ASN1_VALUE_pop(sktmp);
				ASN1_item_ex_free(&vtmp,
						ASN1_ITEM_ptr(tt->item));
				}
			}
				
		if (!*val)
			{
			OPENSSL_PUT_ERROR(ASN1, asn1_template_noexp_d2i,  ERR_R_MALLOC_FAILURE);
			goto err;
			}

		/* Read as many items as we can */
		while(len > 0)
			{
			ASN1_VALUE *skfield;
			const unsigned char *q = p;
			/* See if EOC found */
			if (asn1_check_eoc(&p, len))
				{
				if (!sk_eoc)
					{
					OPENSSL_PUT_ERROR(ASN1, asn1_template_noexp_d2i,  ASN1_R_UNEXPECTED_EOC);
					goto err;
					}
				len -= p - q;
				sk_eoc = 0;
				break;
				}
			skfield = NULL;
			if (!ASN1_item_ex_d2i(&skfield, &p, len,
						ASN1_ITEM_ptr(tt->item),
						-1, 0, 0, ctx))
				{
				OPENSSL_PUT_ERROR(ASN1, asn1_template_noexp_d2i,  ASN1_R_NESTED_ASN1_ERROR);
				goto err;
				}
			len -= p - q;
			if (!sk_ASN1_VALUE_push((STACK_OF(ASN1_VALUE) *)*val,
						skfield))
				{
				OPENSSL_PUT_ERROR(ASN1, asn1_template_noexp_d2i,  ERR_R_MALLOC_FAILURE);
				goto err;
				}
			}
		if (sk_eoc)
			{
			OPENSSL_PUT_ERROR(ASN1, asn1_template_noexp_d2i,  ASN1_R_MISSING_EOC);
			goto err;
			}
		}
	else if (flags & ASN1_TFLG_IMPTAG)
		{
		/* IMPLICIT tagging */
		ret = ASN1_item_ex_d2i(val, &p, len,
			ASN1_ITEM_ptr(tt->item), tt->tag, aclass, opt, ctx);
		if (!ret)
			{
			OPENSSL_PUT_ERROR(ASN1, asn1_template_noexp_d2i,  ASN1_R_NESTED_ASN1_ERROR);
			goto err;
			}
		else if (ret == -1)
			return -1;
		}
	else
		{
		/* Nothing special */
		ret = ASN1_item_ex_d2i(val, &p, len, ASN1_ITEM_ptr(tt->item),
							-1, 0, opt, ctx);
		if (!ret)
			{
			OPENSSL_PUT_ERROR(ASN1, asn1_template_noexp_d2i,  ASN1_R_NESTED_ASN1_ERROR);
			goto err;
			}
		else if (ret == -1)
			return -1;
		}

	*in = p;
	return 1;

	err:
	ASN1_template_free(val, tt);
	return 0;
	}

static int asn1_d2i_ex_primitive(ASN1_VALUE **pval,
				const unsigned char **in, long inlen, 
				const ASN1_ITEM *it,
				int tag, int aclass, char opt, ASN1_TLC *ctx)
	{
	int ret = 0, utype;
	long plen;
	char cst, inf, free_cont = 0;
	const unsigned char *p;
	BUF_MEM buf;
	const unsigned char *cont = NULL;
	long len; 
	if (!pval)
		{
		OPENSSL_PUT_ERROR(ASN1, asn1_d2i_ex_primitive,  ASN1_R_ILLEGAL_NULL);
		return 0; /* Should never happen */
		}

	if (it->itype == ASN1_ITYPE_MSTRING)
		{
		utype = tag;
		tag = -1;
		}
	else
		utype = it->utype;

	if (utype == V_ASN1_ANY)
		{
		/* If type is ANY need to figure out type from tag */
		unsigned char oclass;
		if (tag >= 0)
			{
			OPENSSL_PUT_ERROR(ASN1, asn1_d2i_ex_primitive,  ASN1_R_ILLEGAL_TAGGED_ANY);
			return 0;
			}
		if (opt)
			{
			OPENSSL_PUT_ERROR(ASN1, asn1_d2i_ex_primitive,  ASN1_R_ILLEGAL_OPTIONAL_ANY);
			return 0;
			}
		p = *in;
		ret = asn1_check_tlen(NULL, &utype, &oclass, NULL, NULL,
					&p, inlen, -1, 0, 0, ctx);
		if (!ret)
			{
			OPENSSL_PUT_ERROR(ASN1, asn1_d2i_ex_primitive,  ASN1_R_NESTED_ASN1_ERROR);
			return 0;
			}
		if (oclass != V_ASN1_UNIVERSAL)
			utype = V_ASN1_OTHER;
		}
	if (tag == -1)
		{
		tag = utype;
		aclass = V_ASN1_UNIVERSAL;
		}
	p = *in;
	/* Check header */
	ret = asn1_check_tlen(&plen, NULL, NULL, &inf, &cst,
				&p, inlen, tag, aclass, opt, ctx);
	if (!ret)
		{
		OPENSSL_PUT_ERROR(ASN1, asn1_d2i_ex_primitive,  ASN1_R_NESTED_ASN1_ERROR);
		return 0;
		}
	else if (ret == -1)
		return -1;
        ret = 0;
	/* SEQUENCE, SET and "OTHER" are left in encoded form */
	if ((utype == V_ASN1_SEQUENCE)
		|| (utype == V_ASN1_SET) || (utype == V_ASN1_OTHER))
		{
		/* Clear context cache for type OTHER because the auto clear
		 * when we have a exact match wont work
		 */
		if (utype == V_ASN1_OTHER)
			{
			asn1_tlc_clear(ctx);
			}
		/* SEQUENCE and SET must be constructed */
		else if (!cst)
			{
			OPENSSL_PUT_ERROR(ASN1, asn1_d2i_ex_primitive,  ASN1_R_TYPE_NOT_CONSTRUCTED);
			return 0;
			}

		cont = *in;
		/* If indefinite length constructed find the real end */
		if (inf)
			{
			if (!asn1_find_end(&p, plen, inf))
				 goto err;
			len = p - cont;
			}
		else
			{
			len = p - cont + plen;
			p += plen;
			buf.data = NULL;
			}
		}
	else if (cst)
		{
		if (utype == V_ASN1_NULL || utype == V_ASN1_BOOLEAN
			|| utype == V_ASN1_OBJECT || utype == V_ASN1_INTEGER
			|| utype == V_ASN1_ENUMERATED)
			{
			/* These types only have primitive encodings. */
			OPENSSL_PUT_ERROR(ASN1, asn1_d2i_ex_primitive,
				ASN1_R_TYPE_NOT_PRIMITIVE);
			return 0;
			}

		buf.length = 0;
		buf.max = 0;
		buf.data = NULL;
		/* Should really check the internal tags are correct but
		 * some things may get this wrong. The relevant specs
		 * say that constructed string types should be OCTET STRINGs
		 * internally irrespective of the type. So instead just check
		 * for UNIVERSAL class and ignore the tag.
		 */
		if (!asn1_collect(&buf, &p, plen, inf, -1, V_ASN1_UNIVERSAL, 0))
			{
			free_cont = 1;
			goto err;
			}
		len = buf.length;
		/* Append a final null to string */
		if (!BUF_MEM_grow_clean(&buf, len + 1))
			{
			OPENSSL_PUT_ERROR(ASN1, asn1_d2i_ex_primitive,  ERR_R_MALLOC_FAILURE);
			return 0;
			}
		buf.data[len] = 0;
		cont = (const unsigned char *)buf.data;
		free_cont = 1;
		}
	else
		{
		cont = p;
		len = plen;
		p += plen;
		}

	/* We now have content length and type: translate into a structure */
	if (!asn1_ex_c2i(pval, cont, len, utype, &free_cont, it))
		goto err;

	*in = p;
	ret = 1;
	err:
	if (free_cont && buf.data) OPENSSL_free(buf.data);
	return ret;
	}

/* Translate ASN1 content octets into a structure */

int asn1_ex_c2i(ASN1_VALUE **pval, const unsigned char *cont, int len,
			int utype, char *free_cont, const ASN1_ITEM *it)
	{
	ASN1_VALUE **opval = NULL;
	ASN1_STRING *stmp;
	ASN1_TYPE *typ = NULL;
	int ret = 0;
	const ASN1_PRIMITIVE_FUNCS *pf;
	ASN1_INTEGER **tint;
	pf = it->funcs;

	if (pf && pf->prim_c2i)
		return pf->prim_c2i(pval, cont, len, utype, free_cont, it);
	/* If ANY type clear type and set pointer to internal value */
	if (it->utype == V_ASN1_ANY)
		{
		if (!*pval)
			{
			typ = ASN1_TYPE_new();
			if (typ == NULL)
				goto err;
			*pval = (ASN1_VALUE *)typ;
			}
		else
			typ = (ASN1_TYPE *)*pval;

		if (utype != typ->type)
			ASN1_TYPE_set(typ, utype, NULL);
		opval = pval;
		pval = &typ->value.asn1_value;
		}
	switch(utype)
		{
		case V_ASN1_OBJECT:
		if (!c2i_ASN1_OBJECT((ASN1_OBJECT **)pval, &cont, len))
			goto err;
		break;

		case V_ASN1_NULL:
		if (len)
			{
			OPENSSL_PUT_ERROR(ASN1, asn1_ex_c2i,  ASN1_R_NULL_IS_WRONG_LENGTH);
			goto err;
			}
		*pval = (ASN1_VALUE *)1;
		break;

		case V_ASN1_BOOLEAN:
		if (len != 1)
			{
			OPENSSL_PUT_ERROR(ASN1, asn1_ex_c2i,  ASN1_R_BOOLEAN_IS_WRONG_LENGTH);
			goto err;
			}
		else
			{
			ASN1_BOOLEAN *tbool;
			tbool = (ASN1_BOOLEAN *)pval;
			*tbool = *cont;
			}
		break;

		case V_ASN1_BIT_STRING:
		if (!c2i_ASN1_BIT_STRING((ASN1_BIT_STRING **)pval, &cont, len))
			goto err;
		break;

		case V_ASN1_INTEGER:
		case V_ASN1_NEG_INTEGER:
		case V_ASN1_ENUMERATED:
		case V_ASN1_NEG_ENUMERATED:
		tint = (ASN1_INTEGER **)pval;
		if (!c2i_ASN1_INTEGER(tint, &cont, len))
			goto err;
		/* Fixup type to match the expected form */
		(*tint)->type = utype | ((*tint)->type & V_ASN1_NEG);
		break;

		case V_ASN1_OCTET_STRING:
		case V_ASN1_NUMERICSTRING:
		case V_ASN1_PRINTABLESTRING:
		case V_ASN1_T61STRING:
		case V_ASN1_VIDEOTEXSTRING:
		case V_ASN1_IA5STRING:
		case V_ASN1_UTCTIME:
		case V_ASN1_GENERALIZEDTIME:
		case V_ASN1_GRAPHICSTRING:
		case V_ASN1_VISIBLESTRING:
		case V_ASN1_GENERALSTRING:
		case V_ASN1_UNIVERSALSTRING:
		case V_ASN1_BMPSTRING:
		case V_ASN1_UTF8STRING:
		case V_ASN1_OTHER:
		case V_ASN1_SET:
		case V_ASN1_SEQUENCE:
		default:
		if (utype == V_ASN1_BMPSTRING && (len & 1))
			{
			OPENSSL_PUT_ERROR(ASN1, asn1_ex_c2i,  ASN1_R_BMPSTRING_IS_WRONG_LENGTH);
			goto err;
			}
		if (utype == V_ASN1_UNIVERSALSTRING && (len & 3))
			{
			OPENSSL_PUT_ERROR(ASN1, asn1_ex_c2i,  ASN1_R_UNIVERSALSTRING_IS_WRONG_LENGTH);
			goto err;
			}
		/* All based on ASN1_STRING and handled the same */
		if (!*pval)
			{
			stmp = ASN1_STRING_type_new(utype);
			if (!stmp)
				{
				OPENSSL_PUT_ERROR(ASN1, asn1_ex_c2i,  ERR_R_MALLOC_FAILURE);
				goto err;
				}
			*pval = (ASN1_VALUE *)stmp;
			}
		else
			{
			stmp = (ASN1_STRING *)*pval;
			stmp->type = utype;
			}
		/* If we've already allocated a buffer use it */
		if (*free_cont)
			{
			if (stmp->data)
				OPENSSL_free(stmp->data);
			stmp->data = (unsigned char *)cont; /* UGLY CAST! RL */
			stmp->length = len;
			*free_cont = 0;
			}
		else
			{
			if (!ASN1_STRING_set(stmp, cont, len))
				{
				OPENSSL_PUT_ERROR(ASN1, asn1_ex_c2i,  ERR_R_MALLOC_FAILURE);
				ASN1_STRING_free(stmp);	
				*pval = NULL;
				goto err;
				}
			}
		break;
		}
	/* If ASN1_ANY and NULL type fix up value */
	if (typ && (utype == V_ASN1_NULL))
		 typ->value.ptr = NULL;

	ret = 1;
	err:
	if (!ret)
		{
		ASN1_TYPE_free(typ);
		if (opval)
			*opval = NULL;
		}
	return ret;
	}


/* This function finds the end of an ASN1 structure when passed its maximum
 * length, whether it is indefinite length and a pointer to the content.
 * This is more efficient than calling asn1_collect because it does not
 * recurse on each indefinite length header.
 */

static int asn1_find_end(const unsigned char **in, long len, char inf)
	{
	int expected_eoc;
	long plen;
	const unsigned char *p = *in, *q;
	/* If not indefinite length constructed just add length */
	if (inf == 0)
		{
		*in += len;
		return 1;
		}
	expected_eoc = 1;
	/* Indefinite length constructed form. Find the end when enough EOCs
	 * are found. If more indefinite length constructed headers
	 * are encountered increment the expected eoc count otherwise just
	 * skip to the end of the data.
	 */
	while (len > 0)
		{
		if(asn1_check_eoc(&p, len))
			{
			expected_eoc--;
			if (expected_eoc == 0)
				break;
			len -= 2;
			continue;
			}
		q = p;
		/* Just read in a header: only care about the length */
		if(!asn1_check_tlen(&plen, NULL, NULL, &inf, NULL, &p, len,
				-1, 0, 0, NULL))
			{
			OPENSSL_PUT_ERROR(ASN1, asn1_find_end,  ASN1_R_NESTED_ASN1_ERROR);
			return 0;
			}
		if (inf)
			expected_eoc++;
		else
			p += plen;
		len -= p - q;
		}
	if (expected_eoc)
		{
		OPENSSL_PUT_ERROR(ASN1, asn1_find_end,  ASN1_R_MISSING_EOC);
		return 0;
		}
	*in = p;
	return 1;
	}
/* This function collects the asn1 data from a constructred string
 * type into a buffer. The values of 'in' and 'len' should refer
 * to the contents of the constructed type and 'inf' should be set
 * if it is indefinite length.
 */

#ifndef ASN1_MAX_STRING_NEST
/* This determines how many levels of recursion are permitted in ASN1
 * string types. If it is not limited stack overflows can occur. If set
 * to zero no recursion is allowed at all. Although zero should be adequate
 * examples exist that require a value of 1. So 5 should be more than enough.
 */
#define ASN1_MAX_STRING_NEST 5
#endif


static int asn1_collect(BUF_MEM *buf, const unsigned char **in, long len,
			char inf, int tag, int aclass, int depth)
	{
	const unsigned char *p, *q;
	long plen;
	char cst, ininf;
	p = *in;
	inf &= 1;
	/* If no buffer and not indefinite length constructed just pass over
	 * the encoded data */
	if (!buf && !inf)
		{
		*in += len;
		return 1;
		}
	while(len > 0)
		{
		q = p;
		/* Check for EOC */
		if (asn1_check_eoc(&p, len))
			{
			/* EOC is illegal outside indefinite length
			 * constructed form */
			if (!inf)
				{
				OPENSSL_PUT_ERROR(ASN1, asn1_collect,  ASN1_R_UNEXPECTED_EOC);
				return 0;
				}
			inf = 0;
			break;
			}

		if (!asn1_check_tlen(&plen, NULL, NULL, &ininf, &cst, &p,
					len, tag, aclass, 0, NULL))
			{
			OPENSSL_PUT_ERROR(ASN1, asn1_collect,  ASN1_R_NESTED_ASN1_ERROR);
			return 0;
			}

		/* If indefinite length constructed update max length */
		if (cst)
			{
			if (depth >= ASN1_MAX_STRING_NEST)
				{
				OPENSSL_PUT_ERROR(ASN1, asn1_collect,  ASN1_R_NESTED_ASN1_STRING);
				return 0;
				}
			if (!asn1_collect(buf, &p, plen, ininf, tag, aclass,
						depth + 1))
				return 0;
			}
		else if (plen && !collect_data(buf, &p, plen))
			return 0;
		len -= p - q;
		}
	if (inf)
		{
		OPENSSL_PUT_ERROR(ASN1, asn1_collect,  ASN1_R_MISSING_EOC);
		return 0;
		}
	*in = p;
	return 1;
	}

static int collect_data(BUF_MEM *buf, const unsigned char **p, long plen)
	{
	int len;
	if (buf)
		{
		len = buf->length;
		if (!BUF_MEM_grow_clean(buf, len + plen))
			{
			OPENSSL_PUT_ERROR(ASN1, asn1_collect,  ERR_R_MALLOC_FAILURE);
			return 0;
			}
		memcpy(buf->data + len, *p, plen);
		}
	*p += plen;
	return 1;
	}

/* Check for ASN1 EOC and swallow it if found */

static int asn1_check_eoc(const unsigned char **in, long len)
	{
	const unsigned char *p;
	if (len < 2) return 0;
	p = *in;
	if (!p[0] && !p[1])
		{
		*in += 2;
		return 1;
		}
	return 0;
	}

/* Check an ASN1 tag and length: a bit like ASN1_get_object
 * but it sets the length for indefinite length constructed
 * form, we don't know the exact length but we can set an
 * upper bound to the amount of data available minus the
 * header length just read.
 */

static int asn1_check_tlen(long *olen, int *otag, unsigned char *oclass,
				char *inf, char *cst,
				const unsigned char **in, long len,
				int exptag, int expclass, char opt,
				ASN1_TLC *ctx)
	{
	int i;
	int ptag, pclass;
	long plen;
	const unsigned char *p, *q;
	p = *in;
	q = p;

	if (ctx && ctx->valid)
		{
		i = ctx->ret;
		plen = ctx->plen;
		pclass = ctx->pclass;
		ptag = ctx->ptag;
		p += ctx->hdrlen;
		}
	else
		{
		i = ASN1_get_object(&p, &plen, &ptag, &pclass, len);
		if (ctx)
			{
			ctx->ret = i;
			ctx->plen = plen;
			ctx->pclass = pclass;
			ctx->ptag = ptag;
			ctx->hdrlen = p - q;
			ctx->valid = 1;
			/* If definite length, and no error, length +
			 * header can't exceed total amount of data available. 
			 */
			if (!(i & 0x81) && ((plen + ctx->hdrlen) > len))
				{
				OPENSSL_PUT_ERROR(ASN1, asn1_check_tlen,  ASN1_R_TOO_LONG);
				asn1_tlc_clear(ctx);
				return 0;
				}
			}
		}

	if (i & 0x80)
		{
		OPENSSL_PUT_ERROR(ASN1, asn1_check_tlen,  ASN1_R_BAD_OBJECT_HEADER);
		asn1_tlc_clear(ctx);
		return 0;
		}
	if (exptag >= 0)
		{
		if ((exptag != ptag) || (expclass != pclass))
			{
			/* If type is OPTIONAL, not an error:
			 * indicate missing type.
			 */
			if (opt) return -1;
			asn1_tlc_clear(ctx);
			OPENSSL_PUT_ERROR(ASN1, asn1_check_tlen,  ASN1_R_WRONG_TAG);
			return 0;
			}
		/* We have a tag and class match:
		 * assume we are going to do something with it */
		asn1_tlc_clear(ctx);
		}

	if (i & 1)
		plen = len - (p - q);

	if (inf)
		*inf = i & 1;

	if (cst)
		*cst = i & V_ASN1_CONSTRUCTED;

	if (olen)
		*olen = plen;

	if (oclass)
		*oclass = pclass;

	if (otag)
		*otag = ptag;

	*in = p;
	return 1;
	}