/*

 * Copyright 2000-2026 The OpenSSL Project Authors. All Rights Reserved.

 *

 * Licensed under the Apache License 2.0 (the "License").  You may not use

 * this file except in compliance with the License.  You can obtain a copy

 * in the file LICENSE in the source distribution or at

 * https://www.openssl.org/source/license.html

 */

#include <stddef.h>

#include <openssl/asn1.h>

#include <openssl/asn1t.h>

#include <openssl/objects.h>

#include "asn1_local.h"

/* Free up an ASN1 structure */

void ASN1_item_free(ASN1_VALUE *val, const ASN1_ITEM *it)

{

    ossl_asn1_item_embed_free(&val, it, 0);

}

void ASN1_item_ex_free(ASN1_VALUE **pval, const ASN1_ITEM *it)

{

    ossl_asn1_item_embed_free(pval, it, 0);

}

void ossl_asn1_item_embed_free(ASN1_VALUE **pval, const ASN1_ITEM *it, int embed)

{

    const ASN1_TEMPLATE *tt = NULL, *seqtt;

    const ASN1_EXTERN_FUNCS *ef;

    const ASN1_AUX *aux = it->funcs;

    ASN1_aux_cb *asn1_cb;

    int i;

    if (pval == NULL)

        return;

    if ((it->itype != ASN1_ITYPE_PRIMITIVE) && *pval == NULL)

        return;

    if (aux && aux->asn1_cb)

        asn1_cb = aux->asn1_cb;

    else

        asn1_cb = 0;

    switch (it->itype) {

    case ASN1_ITYPE_PRIMITIVE:

        if (it->templates)

            ossl_asn1_template_free(pval, it->templates);

        else

            ossl_asn1_primitive_free(pval, it, embed);

        break;

    case ASN1_ITYPE_MSTRING:

        ossl_asn1_primitive_free(pval, it, embed);

        break;

    case ASN1_ITYPE_CHOICE:

        if (asn1_cb) {

            i = asn1_cb(ASN1_OP_FREE_PRE, pval, it, NULL);

            if (i == 2)

                return;

        }

        i = ossl_asn1_get_choice_selector(pval, it);

        if ((i >= 0) && (i < it->tcount)) {

            ASN1_VALUE **pchval;

            tt = it->templates + i;

            pchval = ossl_asn1_get_field_ptr(pval, tt);

            ossl_asn1_template_free(pchval, tt);

        }

        if (asn1_cb)

            asn1_cb(ASN1_OP_FREE_POST, pval, it, NULL);

        if (embed == 0) {

            OPENSSL_free(*pval);

            *pval = NULL;

        }

        break;

    case ASN1_ITYPE_EXTERN:

        ef = it->funcs;

        if (ef && ef->asn1_ex_free)

            ef->asn1_ex_free(pval, it);

        break;

    case ASN1_ITYPE_NDEF_SEQUENCE:

    case ASN1_ITYPE_SEQUENCE:

        if (ossl_asn1_do_lock(pval, -1, it) != 0) {

            /* if error or ref-counter > 0 */

            OPENSSL_assert(embed == 0);

            *pval = NULL;

            return;

        }

        if (asn1_cb) {

            i = asn1_cb(ASN1_OP_FREE_PRE, pval, it, NULL);

            if (i == 2)

                return;

        }

        ossl_asn1_enc_free(pval, it);

        /*

         * If we free up as normal we will invalidate any ANY DEFINED BY

         * field and we won't be able to determine the type of the field it

         * defines. So free up in reverse order.

         */

        tt = it->templates + it->tcount;

        for (i = 0; i < it->tcount; i++) {

            ASN1_VALUE **pseqval;

            tt--;

            seqtt = ossl_asn1_do_adb(*pval, tt, 0);

            if (!seqtt)

                continue;

            pseqval = ossl_asn1_get_field_ptr(pval, seqtt);

            ossl_asn1_template_free(pseqval, seqtt);

        }

        if (asn1_cb)

            asn1_cb(ASN1_OP_FREE_POST, pval, it, NULL);

        if (embed == 0) {

            OPENSSL_free(*pval);

            *pval = NULL;

        }

        break;

    }

}

void ossl_asn1_template_free(ASN1_VALUE **pval, const ASN1_TEMPLATE *tt)

{

    int embed = tt->flags & ASN1_TFLG_EMBED;

    ASN1_VALUE *tval;

    if (embed) {

        tval = (ASN1_VALUE *)pval;

        pval = &tval;

    }

    if (tt->flags & ASN1_TFLG_SK_MASK) {

        STACK_OF(ASN1_VALUE) *sk = (STACK_OF(ASN1_VALUE) *)*pval;

        int i;

        for (i = 0; i < sk_ASN1_VALUE_num(sk); i++) {

            ASN1_VALUE *vtmp = sk_ASN1_VALUE_value(sk, i);

            ossl_asn1_item_embed_free(&vtmp, ASN1_ITEM_ptr(tt->item), embed);

        }

        sk_ASN1_VALUE_free(sk);

        *pval = NULL;

    } else {

        ossl_asn1_item_embed_free(pval, ASN1_ITEM_ptr(tt->item), embed);

    }

}

void ossl_asn1_primitive_free(ASN1_VALUE **pval, const ASN1_ITEM *it, int embed)

{

    int utype;

    /* Special case: if 'it' is a primitive with a free_func, use that. */

    if (it) {

        const ASN1_PRIMITIVE_FUNCS *pf = it->funcs;

        if (embed) {

            if (pf && pf->prim_clear) {

                pf->prim_clear(pval, it);

                return;

            }

        } else if (pf && pf->prim_free) {

            pf->prim_free(pval, it);

            return;

        }

    }

    /* Special case: if 'it' is NULL, free contents of ASN1_TYPE */

    if (!it) {

        ASN1_TYPE *typ = (ASN1_TYPE *)*pval;

        utype = typ->type;

        pval = &typ->value.asn1_value;

        if (*pval == NULL)

            return;

    } else if (it->itype == ASN1_ITYPE_MSTRING) {

        utype = -1;

        if (*pval == NULL)

            return;

    } else {

        utype = it->utype;

        if ((utype != V_ASN1_BOOLEAN) && *pval == NULL)

            return;

    }

    switch (utype) {

    case V_ASN1_OBJECT:

        ASN1_OBJECT_free((ASN1_OBJECT *)*pval);

        break;

    case V_ASN1_BOOLEAN:

        if (it)

            *(ASN1_BOOLEAN *)pval = it->size;

        else

            *(ASN1_BOOLEAN *)pval = -1;

        return;

    case V_ASN1_NULL:

        break;

    case V_ASN1_ANY:

        ossl_asn1_primitive_free(pval, NULL, 0);

        OPENSSL_free(*pval);

        break;

    default:

        ossl_asn1_string_free_internal((ASN1_STRING *)*pval, 0, embed);

        break;

    }

    *pval = NULL;

}