tasn_dec.c 36.7 KB
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/* tasn_dec.c */
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/*
 * Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL project
 * 2000.
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 */
/* ====================================================================
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 * Copyright (c) 2000-2005 The OpenSSL Project.  All rights reserved.
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 *
 * 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
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 *    notice, this list of conditions and the following disclaimer.
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 *
 * 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>
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#include <string.h>
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#include <openssl/asn1.h>
#include <openssl/asn1t.h>
#include <openssl/objects.h>
#include <openssl/buffer.h>
#include <openssl/err.h>
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#include "asn1_locl.h"
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static int asn1_check_eoc(const unsigned char **in, long len);
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static int asn1_find_end(const unsigned char **in, long len, char inf);
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static int asn1_collect(BUF_MEM *buf, const unsigned char **in, long len,
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                        char inf, int tag, int aclass, int depth);
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static int collect_data(BUF_MEM *buf, const unsigned char **p, long plen);
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static int asn1_check_tlen(long *olen, int *otag, unsigned char *oclass,
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                           char *inf, char *cst,
                           const unsigned char **in, long len,
                           int exptag, int expclass, char opt, ASN1_TLC *ctx);
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static int asn1_template_ex_d2i(ASN1_VALUE **pval,
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                                const unsigned char **in, long len,
                                const ASN1_TEMPLATE *tt, char opt,
                                ASN1_TLC *ctx);
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static int asn1_template_noexp_d2i(ASN1_VALUE **val,
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                                   const unsigned char **in, long len,
                                   const ASN1_TEMPLATE *tt, char opt,
                                   ASN1_TLC *ctx);
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static int asn1_d2i_ex_primitive(ASN1_VALUE **pval,
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                                 const unsigned char **in, long len,
                                 const ASN1_ITEM *it,
                                 int tag, int aclass, char opt,
                                 ASN1_TLC *ctx);
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static int asn1_ex_c2i(ASN1_VALUE **pval, const unsigned char *cont, int len,
                       int utype, char *free_cont, const ASN1_ITEM *it);
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/* Table to convert tags to bit values, used for MSTRING type */
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static const unsigned long tag2bit[32] = {
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    /* tags  0 -  3 */
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    0, 0, 0, B_ASN1_BIT_STRING,
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    /* tags  4- 7 */
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    B_ASN1_OCTET_STRING, 0, 0, B_ASN1_UNKNOWN,
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    /* tags  8-11 */
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    B_ASN1_UNKNOWN, B_ASN1_UNKNOWN, B_ASN1_UNKNOWN, B_ASN1_UNKNOWN,
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    /* tags 12-15 */
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    B_ASN1_UTF8STRING, B_ASN1_UNKNOWN, B_ASN1_UNKNOWN, B_ASN1_UNKNOWN,
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    /* tags 16-19 */
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    B_ASN1_SEQUENCE, 0, B_ASN1_NUMERICSTRING, B_ASN1_PRINTABLESTRING,
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    /* tags 20-22 */
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    B_ASN1_T61STRING, B_ASN1_VIDEOTEXSTRING, B_ASN1_IA5STRING,
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    /* tags 23-24 */
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    B_ASN1_UTCTIME, B_ASN1_GENERALIZEDTIME,
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    /* tags 25-27 */
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    B_ASN1_GRAPHICSTRING, B_ASN1_ISO64STRING, B_ASN1_GENERALSTRING,
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    /* tags 28-31 */
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    B_ASN1_UNIVERSALSTRING, B_ASN1_UNKNOWN, B_ASN1_BMPSTRING, B_ASN1_UNKNOWN,
};
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unsigned long ASN1_tag2bit(int tag)
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{
    if ((tag < 0) || (tag > 30))
        return 0;
    return tag2bit[tag];
}
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/* Macro to initialize and invalidate the cache */

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

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ASN1_VALUE *ASN1_item_d2i(ASN1_VALUE **pval,
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                          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;
}
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/*
 * Decode an item, taking care of IMPLICIT tagging, if any. If 'opt' set and
 * tag mismatch return -1 to handle OPTIONAL
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 */

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int ASN1_item_ex_d2i(ASN1_VALUE **pval, const unsigned char **in, long len,
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                     const ASN1_ITEM *it,
                     int tag, int aclass, char opt, ASN1_TLC *ctx)
{
    const ASN1_TEMPLATE *tt, *errtt = NULL;
    const ASN1_EXTERN_FUNCS *ef;
    const ASN1_AUX *aux = it->funcs;
    ASN1_aux_cb *asn1_cb;
    const unsigned char *p = NULL, *q;
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    unsigned char oclass;
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    char seq_eoc, seq_nolen, cst, isopt;
    long tmplen;
    int i;
    int otag;
    int ret = 0;
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    ASN1_VALUE **pchptr;
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    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);

    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_CHOICE:
        if (asn1_cb && !asn1_cb(ASN1_OP_D2I_PRE, pval, it, NULL))
            goto auxerr;
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        if (*pval) {
            /* Free up and zero CHOICE value if initialised */
            i = asn1_get_choice_selector(pval, it);
            if ((i >= 0) && (i < it->tcount)) {
                tt = it->templates + i;
                pchptr = asn1_get_field_ptr(pval, tt);
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                asn1_template_free(pchptr, tt);
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                asn1_set_choice_selector(pval, -1, it);
            }
        } else if (!ASN1_item_ex_new(pval, it)) {
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            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);
        if (asn1_cb && !asn1_cb(ASN1_OP_D2I_POST, pval, it, NULL))
            goto auxerr;
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        *in = p;
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        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;

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        /* Free up and zero any ADB found */
        for (i = 0, tt = it->templates; i < it->tcount; i++, tt++) {
            if (tt->flags & ASN1_TFLG_ADB_MASK) {
                const ASN1_TEMPLATE *seqtt;
                ASN1_VALUE **pseqval;
                seqtt = asn1_do_adb(pval, tt, 1);
                pseqval = asn1_get_field_ptr(pval, seqtt);
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                asn1_template_free(pseqval, seqtt);
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            }
        }

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        /* 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.
                 */
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                asn1_template_free(pseqval, seqtt);
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                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);
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                asn1_template_free(pseqval, seqtt);
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            } 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;
        if (asn1_cb && !asn1_cb(ASN1_OP_D2I_POST, pval, it, NULL))
            goto auxerr;
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        *in = p;
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        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.
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 */

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static int asn1_template_ex_d2i(ASN1_VALUE **val,
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                                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:
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    asn1_template_free(val, tt);
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    return 0;
}
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static int asn1_template_noexp_d2i(ASN1_VALUE **val,
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                                   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:
635
    asn1_template_free(val, tt);
636 637
    return 0;
}
D
 
Dr. Stephen Henson 已提交
638

639
static int asn1_d2i_ex_primitive(ASN1_VALUE **pval,
640 641 642 643 644 645 646 647
                                 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;
648
    BUF_MEM buf = { 0 };
649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767
    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) {
        if (utype == V_ASN1_NULL || utype == V_ASN1_BOOLEAN
            || utype == V_ASN1_OBJECT || utype == V_ASN1_INTEGER
            || utype == V_ASN1_ENUMERATED) {
            ASN1err(ASN1_F_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)) {
            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:
R
Rich Salz 已提交
768
    if (free_cont)
769 770 771
        OPENSSL_free(buf.data);
    return ret;
}
D
 
Dr. Stephen Henson 已提交
772 773 774

/* Translate ASN1 content octets into a structure */

775 776
static int asn1_ex_c2i(ASN1_VALUE **pval, const unsigned char *cont, int len,
                       int utype, char *free_cont, const ASN1_ITEM *it)
777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884
{
    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) {
R
Rich Salz 已提交
885
            OPENSSL_free(stmp->data);
886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917
            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.
918 919 920
 */

static int asn1_find_end(const unsigned char **in, long len, char inf)
921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969
{
    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.
D
 
Dr. Stephen Henson 已提交
970 971
 */

D
Dr. Stephen Henson 已提交
972
#ifndef ASN1_MAX_STRING_NEST
973 974 975 976 977
/*
 * 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.
D
Dr. Stephen Henson 已提交
978
 */
979
# define ASN1_MAX_STRING_NEST 5
D
Dr. Stephen Henson 已提交
980 981
#endif

982
static int asn1_collect(BUF_MEM *buf, const unsigned char **in, long len,
983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037
                        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;
}
D
 
Dr. Stephen Henson 已提交
1038

1039
static int collect_data(BUF_MEM *buf, const unsigned char **p, long plen)
1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052
{
    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;
}
D
 
Dr. Stephen Henson 已提交
1053 1054 1055

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

1056
static int asn1_check_eoc(const unsigned char **in, long len)
1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073
{
    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.
D
 
Dr. Stephen Henson 已提交
1074 1075
 */

1076
static int asn1_check_tlen(long *olen, int *otag, unsigned char *oclass,
1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158
                           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;
}