/* tasn_utl.c */

/*

 * Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL project

 * 2000.

 */

/* ====================================================================

 * Copyright (c) 2000-2004 The OpenSSL Project.  All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 *

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 *

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in

 *    the documentation and/or other materials provided with the

 *    distribution.

 *

 * 3. All advertising materials mentioning features or use of this

 *    software must display the following acknowledgment:

 *    "This product includes software developed by the OpenSSL Project

 *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"

 *

 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to

 *    endorse or promote products derived from this software without

 *    prior written permission. For written permission, please contact

 *    licensing@OpenSSL.org.

 *

 * 5. Products derived from this software may not be called "OpenSSL"

 *    nor may "OpenSSL" appear in their names without prior written

 *    permission of the OpenSSL Project.

 *

 * 6. Redistributions of any form whatsoever must retain the following

 *    acknowledgment:

 *    "This product includes software developed by the OpenSSL Project

 *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"

 *

 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY

 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR

 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,

 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT

 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;

 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)

 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,

 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)

 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED

 * OF THE POSSIBILITY OF SUCH DAMAGE.

 * ====================================================================

 *

 * This product includes cryptographic software written by Eric Young

 * (eay@cryptsoft.com).  This product includes software written by Tim

 * Hudson (tjh@cryptsoft.com).

 *

 */

#include <stddef.h>

#include <string.h>

#include <openssl/asn1.h>

#include <openssl/asn1t.h>

#include <openssl/objects.h>

#include <openssl/err.h>

/* Utility functions for manipulating fields and offsets */

/* Add 'offset' to 'addr' */

#define offset2ptr(addr, offset) (void *)(((char *) addr) + offset)

/*

 * Given an ASN1_ITEM CHOICE type return the selector value

 */

int asn1_get_choice_selector(ASN1_VALUE **pval, const ASN1_ITEM *it)

{

    int *sel = offset2ptr(*pval, it->utype);

    return *sel;

}

/*

 * Given an ASN1_ITEM CHOICE type set the selector value, return old value.

 */

int asn1_set_choice_selector(ASN1_VALUE **pval, int value,

                             const ASN1_ITEM *it)

{

    int *sel, ret;

    sel = offset2ptr(*pval, it->utype);

    ret = *sel;

    *sel = value;

    return ret;

}

/*

 * Do reference counting. The value 'op' decides what to do. if it is +1

 * then the count is incremented. If op is 0 count is set to 1. If op is -1

 * count is decremented and the return value is the current refrence count or

 * 0 if no reference count exists.

 */

int asn1_do_lock(ASN1_VALUE **pval, int op, const ASN1_ITEM *it)

{

    const ASN1_AUX *aux;

    int *lck, ret;

    if ((it->itype != ASN1_ITYPE_SEQUENCE)

        && (it->itype != ASN1_ITYPE_NDEF_SEQUENCE))

        return 0;

    aux = it->funcs;

    if (!aux || !(aux->flags & ASN1_AFLG_REFCOUNT))

        return 0;

    lck = offset2ptr(*pval, aux->ref_offset);

    if (op == 0) {

        *lck = 1;

        return 1;

    }

    ret = CRYPTO_add(lck, op, aux->ref_lock);

#ifdef REF_PRINT

    fprintf(stderr, "%s: Reference Count: %d\n", it->sname, *lck);

#endif

#ifdef REF_CHECK

    if (ret < 0)

        fprintf(stderr, "%s, bad reference count\n", it->sname);

#endif

    return ret;

}

static ASN1_ENCODING *asn1_get_enc_ptr(ASN1_VALUE **pval, const ASN1_ITEM *it)

{

    const ASN1_AUX *aux;

    if (!pval || !*pval)

        return NULL;

    aux = it->funcs;

    if (!aux || !(aux->flags & ASN1_AFLG_ENCODING))

        return NULL;

    return offset2ptr(*pval, aux->enc_offset);

}

void asn1_enc_init(ASN1_VALUE **pval, const ASN1_ITEM *it)

{

    ASN1_ENCODING *enc;

    enc = asn1_get_enc_ptr(pval, it);

    if (enc) {

        enc->enc = NULL;

        enc->len = 0;

        enc->modified = 1;

    }

}

void asn1_enc_free(ASN1_VALUE **pval, const ASN1_ITEM *it)

{

    ASN1_ENCODING *enc;

    enc = asn1_get_enc_ptr(pval, it);

    if (enc) {

        if (enc->enc)

            OPENSSL_free(enc->enc);

        enc->enc = NULL;

        enc->len = 0;

        enc->modified = 1;

    }

}

int asn1_enc_save(ASN1_VALUE **pval, const unsigned char *in, int inlen,

                  const ASN1_ITEM *it)

{

    ASN1_ENCODING *enc;

    enc = asn1_get_enc_ptr(pval, it);

    if (!enc)

        return 1;

    if (enc->enc)

        OPENSSL_free(enc->enc);

    enc->enc = OPENSSL_malloc(inlen);

    if (!enc->enc)

        return 0;

    memcpy(enc->enc, in, inlen);

    enc->len = inlen;

    enc->modified = 0;

    return 1;

}

int asn1_enc_restore(int *len, unsigned char **out, ASN1_VALUE **pval,

                     const ASN1_ITEM *it)

{

    ASN1_ENCODING *enc;

    enc = asn1_get_enc_ptr(pval, it);

    if (!enc || enc->modified)

        return 0;

    if (out) {

        memcpy(*out, enc->enc, enc->len);

        *out += enc->len;

    }

    if (len)

        *len = enc->len;

    return 1;

}

/* Given an ASN1_TEMPLATE get a pointer to a field */

ASN1_VALUE **asn1_get_field_ptr(ASN1_VALUE **pval, const ASN1_TEMPLATE *tt)

{

    ASN1_VALUE **pvaltmp;

    if (tt->flags & ASN1_TFLG_COMBINE)

        return pval;

    pvaltmp = offset2ptr(*pval, tt->offset);

    /*

     * NOTE for BOOLEAN types the field is just a plain int so we can't

     * return int **, so settle for (int *).

     */

    return pvaltmp;

}

/*

 * Handle ANY DEFINED BY template, find the selector, look up the relevant

 * ASN1_TEMPLATE in the table and return it.

 */

const ASN1_TEMPLATE *asn1_do_adb(ASN1_VALUE **pval, const ASN1_TEMPLATE *tt,

                                 int nullerr)

{

    const ASN1_ADB *adb;

    const ASN1_ADB_TABLE *atbl;

    long selector;

    ASN1_VALUE **sfld;

    int i;

    if (!(tt->flags & ASN1_TFLG_ADB_MASK))

        return tt;

    /* Else ANY DEFINED BY ... get the table */

    adb = ASN1_ADB_ptr(tt->item);

    /* Get the selector field */

    sfld = offset2ptr(*pval, adb->offset);

    /* Check if NULL */

    if (*sfld == NULL) {

        if (!adb->null_tt)

            goto err;

        return adb->null_tt;

    }

    /*

     * Convert type to a long: NB: don't check for NID_undef here because it

     * might be a legitimate value in the table

     */

    if (tt->flags & ASN1_TFLG_ADB_OID)

        selector = OBJ_obj2nid((ASN1_OBJECT *)*sfld);

    else

        selector = ASN1_INTEGER_get((ASN1_INTEGER *)*sfld);

    /*

     * Try to find matching entry in table Maybe should check application

     * types first to allow application override? Might also be useful to

     * have a flag which indicates table is sorted and we can do a binary

     * search. For now stick to a linear search.

     */

    for (atbl = adb->tbl, i = 0; i < adb->tblcount; i++, atbl++)

        if (atbl->value == selector)

            return &atbl->tt;

    /* FIXME: need to search application table too */

    /* No match, return default type */

    if (!adb->default_tt)

        goto err;

    return adb->default_tt;

 err:

    /* FIXME: should log the value or OID of unsupported type */

    if (nullerr)

        ASN1err(ASN1_F_ASN1_DO_ADB, ASN1_R_UNSUPPORTED_ANY_DEFINED_BY_TYPE);

    return NULL;

}