Don't attempt to parse nested ASN1 strings by default.

[thirdparty/openssl.git] / crypto / asn1 / tasn_dec.c

/* tasn_dec.c */
/* Written by Dr Stephen N Henson (shenson@bigfoot.com) 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).
 *
 */


#include <stddef.h>
#include <string.h>
#include <openssl/asn1.h>
#include <openssl/asn1t.h>
#include <openssl/objects.h>
#include <openssl/buffer.h>
#include <openssl/err.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);

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 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 */
0,      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

/* 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(&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(&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, *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 *pchval, **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)
                                {
                                ASN1err(ASN1_F_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)
                        {
                        ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
                                        ERR_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;
                        ASN1err(ASN1_F_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;
                        ASN1err(ASN1_F_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)
                                {
                                ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
                                        ERR_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;
                        *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;

                ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ERR_R_NESTED_ASN1_ERROR);
                goto err;


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

                /* Allocate structure */
                if (!*pval && !ASN1_item_ex_new(pval, it))
                        {
                        ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
                                                ERR_R_NESTED_ASN1_ERROR);
                        goto err;
                        }
                /* CHOICE type, try each possibility in turn */
                pchval = NULL;
                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;
                        ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
                                                ERR_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;
                                }
                        ASN1err(ASN1_F_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))
                                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)
                        {
                        ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
                                        ERR_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)
                        {
                        ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
                                ASN1_R_SEQUENCE_NOT_CONSTRUCTED);
                        goto err;
                        }

                if (!*pval && !ASN1_item_ex_new(pval, it))
                        {
                        ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
                                ERR_R_NESTED_ASN1_ERROR);
                        goto err;
                        }

                if (asn1_cb && !asn1_cb(ASN1_OP_D2I_PRE, pval, it))
                                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)
                                        {
                                        ASN1err(ASN1_F_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))
                        {
                        ASN1err(ASN1_F_ASN1_ITEM_EX_D2I, ASN1_R_MISSING_EOC);
                        goto err;
                        }
                /* Check all data read */
                if (!seq_nolen && len)
                        {
                        ASN1err(ASN1_F_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;
                                ASN1err(ASN1_F_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))
                                goto auxerr;
                return 1;

                default:
                return 0;
                }
        auxerr:
        ASN1err(ASN1_F_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)
                        {
                        ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I,
                                        ERR_R_NESTED_ASN1_ERROR);
                        return 0;
                        }
                else if (ret == -1)
                        return -1;
                if (!cst)
                        {
                        ASN1err(ASN1_F_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)
                        {
                        ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I,
                                        ERR_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))
                                {
                                ASN1err(ASN1_F_ASN1_TEMPLATE_D2I,
                                                ASN1_R_MISSING_EOC);
                                goto err;
                                }
                        }
                else
                        {
                        /* Otherwise we must hit the EXPLICIT tag end or its
                         * an error */
                        if (len)
                                {
                                ASN1err(ASN1_F_ASN1_TEMPLATE_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);
        *val = NULL;
        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, *q;
        if (!val)
                return 0;
        flags = tt->flags;
        aclass = flags & ASN1_TFLG_TAG_CLASS;

        p = *in;
        q = p;

        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)
                        {
                        ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I,
                                                ERR_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 *sktmp = (STACK *)*val;
                        ASN1_VALUE *vtmp;
                        while(sk_num(sktmp) > 0)
                                {
                                vtmp = (ASN1_VALUE *)sk_pop(sktmp);
                                ASN1_item_ex_free(&vtmp,
                                                ASN1_ITEM_ptr(tt->item));
                                }
                        }
                                
                if (!*val)
                        {
                        ASN1err(ASN1_F_ASN1_TEMPLATE_EX_D2I,
                                                ERR_R_MALLOC_FAILURE);
                        goto err;
                        }

                /* Read as many items as we can */
                while(len > 0)
                        {
                        ASN1_VALUE *skfield;
                        q = p;
                        /* See if EOC found */
                        if (asn1_check_eoc(&p, len))
                                {
                                if (!sk_eoc)
                                        {
                                        ASN1err(ASN1_F_ASN1_TEMPLATE_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))
                                {
                                ASN1err(ASN1_F_ASN1_TEMPLATE_D2I,
                                        ERR_R_NESTED_ASN1_ERROR);
                                goto err;
                                }
                        len -= p - q;
                        if (!sk_push((STACK *)*val, (char *)skfield))
                                {
                                ASN1err(ASN1_F_ASN1_TEMPLATE_D2I,
                                                ERR_R_MALLOC_FAILURE);
                                goto err;
                                }
                        }
                if (sk_eoc)
                        {
                        ASN1err(ASN1_F_ASN1_TEMPLATE_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)
                        {
                        ASN1err(ASN1_F_ASN1_TEMPLATE_D2I,
                                                ERR_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)
                        {
                        ASN1err(ASN1_F_ASN1_TEMPLATE_D2I,
                                        ERR_R_NESTED_ASN1_ERROR);
                        goto err;
                        }
                else if (ret == -1)
                        return -1;
                }

        *in = p;
        return 1;

        err:
        ASN1_template_free(val, tt);
        *val = NULL;
        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)
                {
                ASN1err(ASN1_F_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)
                        {
                        ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
                                        ASN1_R_ILLEGAL_TAGGED_ANY);
                        return 0;
                        }
                if (opt)
                        {
                        ASN1err(ASN1_F_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)
                        {
                        ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
                                        ERR_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)
                {
                ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE, ERR_R_NESTED_ASN1_ERROR);
                return 0;
                }
        else if (ret == -1)
                return -1;
        /* 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)
                        {
                        ASN1err(ASN1_F_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)
                {
                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))
                        goto err;
                len = buf.length;
                /* Append a final null to string */
                if (!BUF_MEM_grow_clean(&buf, len + 1))
                        {
                        ASN1err(ASN1_F_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();
                        *pval = (ASN1_VALUE *)typ;
                        }
                else
                        typ = (ASN1_TYPE *)*pval;

                if (utype != typ->type)
                        ASN1_TYPE_set(typ, utype, NULL);
                opval = pval;
                pval = (ASN1_VALUE **)&typ->value.ptr;
                }
        switch(utype)
                {
                case V_ASN1_OBJECT:
                if (!c2i_ASN1_OBJECT((ASN1_OBJECT **)pval, &cont, len))
                        goto err;
                break;

                case V_ASN1_NULL:
                if (len)
                        {
                        ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
                                                ASN1_R_NULL_IS_WRONG_LENGTH);
                        goto err;
                        }
                *pval = (ASN1_VALUE *)1;
                break;

                case V_ASN1_BOOLEAN:
                if (len != 1)
                        {
                        ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
                                                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:
                /* All based on ASN1_STRING and handled the same */
                if (!*pval)
                        {
                        stmp = ASN1_STRING_type_new(utype);
                        if (!stmp)
                                {
                                ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
                                                        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))
                                {
                                ASN1err(ASN1_F_ASN1_D2I_EX_PRIMITIVE,
                                                        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 justi
         * 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))
                        {
                        ASN1err(ASN1_F_ASN1_FIND_END, ERR_R_NESTED_ASN1_ERROR);
                        return 0;
                        }
                if (inf)
                        expected_eoc++;
                else
                        p += plen;
                len -= p - q;
                }
        if (expected_eoc)
                {
                ASN1err(ASN1_F_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.
 */

static int asn1_collect(BUF_MEM *buf, const unsigned char **in, long len,
                                char inf, int tag, int aclass)
        {
        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)
                                {
                                ASN1err(ASN1_F_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))
                        {
                        ASN1err(ASN1_F_ASN1_COLLECT, ERR_R_NESTED_ASN1_ERROR);
                        return 0;
                        }

                /* If indefinite length constructed update max length */
                if (cst)
                        {
#ifdef OPENSSL_ALLOW_NESTED_ASN1_STRINGS
                        if (!asn1_collect(buf, &p, plen, ininf, tag, aclass))
                                return 0;
#else
                        ASN1err(ASN1_F_ASN1_COLLECT, ASN1_R_NESTED_ASN1_STRING);
                        return 0;
#endif
                        }
                else if (!collect_data(buf, &p, plen))
                        return 0;
                len -= p - q;
                }
        if (inf)
                {
                ASN1err(ASN1_F_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))
                        {
                        ASN1err(ASN1_F_COLLECT_DATA, 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))
                                {
                                ASN1err(ASN1_F_ASN1_CHECK_TLEN,
                                                        ASN1_R_TOO_LONG);
                                asn1_tlc_clear(ctx);
                                return 0;
                                }
                        }
                }

        if (i & 0x80)
                {
                ASN1err(ASN1_F_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);
                        ASN1err(ASN1_F_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;
        }