tasn_dec.c

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/* tasn_dec.c */
/* Written by Dr Stephen N Henson ([email protected]) 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
 *    [email protected].
 *
 * 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
 * ([email protected]).  This product includes software written by Tim
 * Hudson ([email protected]).
 *
 */


#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, 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)
                {
                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;
            if (p == NULL)
                {
                ASN1err(ASN1_F_ASN1_ITEM_EX_D2I,
                    ERR_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;

        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, NULL))
                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 */
        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, 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)
            {
            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, 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)
                    {
                    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, NULL))
                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_EX_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_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, *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_NOEXP_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_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)
            {
            ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_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_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))
                {
                ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
                    ERR_R_NESTED_ASN1_ERROR);
                goto err;
                }
            len -= p - q;
            if (!sk_ASN1_VALUE_push((STACK_OF(ASN1_VALUE) *)*val,
                        skfield))
                {
                ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_D2I,
                        ERR_R_MALLOC_FAILURE);
                goto err;
                }
            }
        if (sk_eoc)
            {
            ASN1err(ASN1_F_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)
            {
            ASN1err(ASN1_F_ASN1_TEMPLATE_NOEXP_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_NOEXP_D2I,
                    ERR_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)
        {
        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;
        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)
            {
            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, 0))
            {
            free_cont = 1;
            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();
            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)
            {
            ASN1err(ASN1_F_ASN1_EX_C2I,
                        ASN1_R_NULL_IS_WRONG_LENGTH);
            goto err;
            }
        *pval = (ASN1_VALUE *)1;
        break;

        case V_ASN1_BOOLEAN:
        if (len != 1)
            {
            ASN1err(ASN1_F_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))
            {
            ASN1err(ASN1_F_ASN1_EX_C2I,
                    ASN1_R_BMPSTRING_IS_WRONG_LENGTH);
            goto err;
            }
        if (utype == V_ASN1_UNIVERSALSTRING && (len & 3))
            {
            ASN1err(ASN1_F_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)
                {
                ASN1err(ASN1_F_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))
                {
                ASN1err(ASN1_F_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))
            {
            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.
 */

#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)
                {
                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)
            {
            if (depth >= ASN1_MAX_STRING_NEST)
                {
                ASN1err(ASN1_F_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)
        {
        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;
    }