/*

 *  X.509 Certificate Revocation List (CRL) parsing

 *

 *  Copyright The Mbed TLS Contributors

 *  SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later

 */

/*

 *  The ITU-T X.509 standard defines a certificate format for PKI.

 *

 *  http://www.ietf.org/rfc/rfc5280.txt (Certificates and CRLs)

 *  http://www.ietf.org/rfc/rfc3279.txt (Alg IDs for CRLs)

 *  http://www.ietf.org/rfc/rfc2986.txt (CSRs, aka PKCS#10)

 *

 *  http://www.itu.int/ITU-T/studygroups/com17/languages/X.680-0207.pdf

 *  http://www.itu.int/ITU-T/studygroups/com17/languages/X.690-0207.pdf

 */

#include "common.h"

#if defined(MBEDTLS_X509_CRL_PARSE_C)

#include "mbedtls/x509_crl.h"

#include "mbedtls/error.h"

#include "mbedtls/oid.h"

#include "mbedtls/platform_util.h"

#include <string.h>

#if defined(MBEDTLS_PEM_PARSE_C)

#include "mbedtls/pem.h"

#endif

#include "mbedtls/platform.h"

#if defined(MBEDTLS_HAVE_TIME)

#if defined(_WIN32) && !defined(EFIX64) && !defined(EFI32)

#include <windows.h>

#else

#include <time.h>

#endif

#endif

#if defined(MBEDTLS_FS_IO) || defined(EFIX64) || defined(EFI32)

#include <stdio.h>

#endif

/*

 *  Version  ::=  INTEGER  {  v1(0), v2(1)  }

 */

static int x509_crl_get_version(unsigned char **p,

                                const unsigned char *end,

                                int *ver)

{

    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;

    if ((ret = mbedtls_asn1_get_int(p, end, ver)) != 0) {

        if (ret == MBEDTLS_ERR_ASN1_UNEXPECTED_TAG) {

            *ver = 0;

            return 0;

        }

        return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_VERSION, ret);

    }

    return 0;

}

/*

 * X.509 CRL v2 extensions

 *

 * We currently don't parse any extension's content, but we do check that the

 * list of extensions is well-formed and abort on critical extensions (that

 * are unsupported as we don't support any extension so far)

 */

static int x509_get_crl_ext(unsigned char **p,

                            const unsigned char *end,

                            mbedtls_x509_buf *ext)

{

    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;

    if (*p == end) {

        return 0;

    }

    /*

     * crlExtensions           [0]  EXPLICIT Extensions OPTIONAL

     *                              -- if present, version MUST be v2

     */

    if ((ret = mbedtls_x509_get_ext(p, end, ext, 0)) != 0) {

        return ret;

    }

    end = ext->p + ext->len;

    while (*p < end) {

        /*

         * Extension  ::=  SEQUENCE  {

         *      extnID      OBJECT IDENTIFIER,

         *      critical    BOOLEAN DEFAULT FALSE,

         *      extnValue   OCTET STRING  }

         */

        int is_critical = 0;

        const unsigned char *end_ext_data;

        size_t len;

        /* Get enclosing sequence tag */

        if ((ret = mbedtls_asn1_get_tag(p, end, &len,

                                        MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) != 0) {

            return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS, ret);

        }

        end_ext_data = *p + len;

        /* Get OID (currently ignored) */

        if ((ret = mbedtls_asn1_get_tag(p, end_ext_data, &len,

                                        MBEDTLS_ASN1_OID)) != 0) {

            return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS, ret);

        }

        *p += len;

        /* Get optional critical */

        if ((ret = mbedtls_asn1_get_bool(p, end_ext_data,

                                         &is_critical)) != 0 &&

            (ret != MBEDTLS_ERR_ASN1_UNEXPECTED_TAG)) {

            return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS, ret);

        }

        /* Data should be octet string type */

        if ((ret = mbedtls_asn1_get_tag(p, end_ext_data, &len,

                                        MBEDTLS_ASN1_OCTET_STRING)) != 0) {

            return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS, ret);

        }

        /* Ignore data so far and just check its length */

        *p += len;

        if (*p != end_ext_data) {

            return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS,

                                     MBEDTLS_ERR_ASN1_LENGTH_MISMATCH);

        }

        /* Abort on (unsupported) critical extensions */

        if (is_critical) {

            return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS,

                                     MBEDTLS_ERR_ASN1_UNEXPECTED_TAG);

        }

    }

    if (*p != end) {

        return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS,

                                 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH);

    }

    return 0;

}

/*

 * X.509 CRL v2 entry extensions (no extensions parsed yet.)

 */

static int x509_get_crl_entry_ext(unsigned char **p,

                                  const unsigned char *end,

                                  mbedtls_x509_buf *ext)

{

    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;

    size_t len = 0;

    /* OPTIONAL */

    if (end <= *p) {

        return 0;

    }

    ext->tag = **p;

    ext->p = *p;

    /*

     * Get CRL-entry extension sequence header

     * crlEntryExtensions      Extensions OPTIONAL  -- if present, MUST be v2

     */

    if ((ret = mbedtls_asn1_get_tag(p, end, &ext->len,

                                    MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) != 0) {

        if (ret == MBEDTLS_ERR_ASN1_UNEXPECTED_TAG) {

            ext->p = NULL;

            return 0;

        }

        return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS, ret);

    }

    end = *p + ext->len;

    if (end != *p + ext->len) {

        return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS,

                                 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH);

    }

    while (*p < end) {

        if ((ret = mbedtls_asn1_get_tag(p, end, &len,

                                        MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) != 0) {

            return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS, ret);

        }

        *p += len;

    }

    if (*p != end) {

        return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_EXTENSIONS,

                                 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH);

    }

    return 0;

}

/*

 * X.509 CRL Entries

 */

static int x509_get_entries(unsigned char **p,

                            const unsigned char *end,

                            mbedtls_x509_crl_entry *entry)

{

    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;

    size_t entry_len;

    mbedtls_x509_crl_entry *cur_entry = entry;

    if (*p == end) {

        return 0;

    }

    if ((ret = mbedtls_asn1_get_tag(p, end, &entry_len,

                                    MBEDTLS_ASN1_SEQUENCE | MBEDTLS_ASN1_CONSTRUCTED)) != 0) {

        if (ret == MBEDTLS_ERR_ASN1_UNEXPECTED_TAG) {

            return 0;

        }

        return ret;

    }

    end = *p + entry_len;

    while (*p < end) {

        size_t len2;

        const unsigned char *end2;

        cur_entry->raw.tag = **p;

        if ((ret = mbedtls_asn1_get_tag(p, end, &len2,

                                        MBEDTLS_ASN1_SEQUENCE | MBEDTLS_ASN1_CONSTRUCTED)) != 0) {

            return ret;

        }

        cur_entry->raw.p = *p;

        cur_entry->raw.len = len2;

        end2 = *p + len2;

        if ((ret = mbedtls_x509_get_serial(p, end2, &cur_entry->serial)) != 0) {

            return ret;

        }

        if ((ret = mbedtls_x509_get_time(p, end2,

                                         &cur_entry->revocation_date)) != 0) {

            return ret;

        }

        if ((ret = x509_get_crl_entry_ext(p, end2,

                                          &cur_entry->entry_ext)) != 0) {

            return ret;

        }

        if (*p < end) {

            cur_entry->next = mbedtls_calloc(1, sizeof(mbedtls_x509_crl_entry));

            if (cur_entry->next == NULL) {

                return MBEDTLS_ERR_X509_ALLOC_FAILED;

            }

            cur_entry = cur_entry->next;

        }

    }

    return 0;

}

/*

 * Parse one  CRLs in DER format and append it to the chained list

 */

int mbedtls_x509_crl_parse_der(mbedtls_x509_crl *chain,

                               const unsigned char *buf, size_t buflen)

{

    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;

    size_t len;

    unsigned char *p = NULL, *end = NULL;

    mbedtls_x509_buf sig_params1, sig_params2, sig_oid2;

    mbedtls_x509_crl *crl = chain;

    /*

     * Check for valid input

     */

    if (crl == NULL || buf == NULL) {

        return MBEDTLS_ERR_X509_BAD_INPUT_DATA;

    }

    memset(&sig_params1, 0, sizeof(mbedtls_x509_buf));

    memset(&sig_params2, 0, sizeof(mbedtls_x509_buf));

    memset(&sig_oid2, 0, sizeof(mbedtls_x509_buf));

    /*

     * Add new CRL on the end of the chain if needed.

     */

    while (crl->version != 0 && crl->next != NULL) {

        crl = crl->next;

    }

    if (crl->version != 0 && crl->next == NULL) {

        crl->next = mbedtls_calloc(1, sizeof(mbedtls_x509_crl));

        if (crl->next == NULL) {

            mbedtls_x509_crl_free(crl);

            return MBEDTLS_ERR_X509_ALLOC_FAILED;

        }

        mbedtls_x509_crl_init(crl->next);

        crl = crl->next;

    }

    /*

     * Copy raw DER-encoded CRL

     */

    if (buflen == 0) {

        return MBEDTLS_ERR_X509_INVALID_FORMAT;

    }

    p = mbedtls_calloc(1, buflen);

    if (p == NULL) {

        return MBEDTLS_ERR_X509_ALLOC_FAILED;

    }

    memcpy(p, buf, buflen);

    crl->raw.p = p;

    crl->raw.len = buflen;

    end = p + buflen;

    /*

     * CertificateList  ::=  SEQUENCE  {

     *      tbsCertList          TBSCertList,

     *      signatureAlgorithm   AlgorithmIdentifier,

     *      signatureValue       BIT STRING  }

     */

    if ((ret = mbedtls_asn1_get_tag(&p, end, &len,

                                    MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) != 0) {

        mbedtls_x509_crl_free(crl);

        return MBEDTLS_ERR_X509_INVALID_FORMAT;

    }

    if (len != (size_t) (end - p)) {

        mbedtls_x509_crl_free(crl);

        return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_FORMAT,

                                 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH);

    }

    /*

     * TBSCertList  ::=  SEQUENCE  {

     */

    crl->tbs.p = p;

    if ((ret = mbedtls_asn1_get_tag(&p, end, &len,

                                    MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) != 0) {

        mbedtls_x509_crl_free(crl);

        return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_FORMAT, ret);

    }

    end = p + len;

    crl->tbs.len = end - crl->tbs.p;

    /*

     * Version  ::=  INTEGER  OPTIONAL {  v1(0), v2(1)  }

     *               -- if present, MUST be v2

     *

     * signature            AlgorithmIdentifier

     */

    if ((ret = x509_crl_get_version(&p, end, &crl->version)) != 0 ||

        (ret = mbedtls_x509_get_alg(&p, end, &crl->sig_oid, &sig_params1)) != 0) {

        mbedtls_x509_crl_free(crl);

        return ret;

    }

    if (crl->version < 0 || crl->version > 1) {

        mbedtls_x509_crl_free(crl);

        return MBEDTLS_ERR_X509_UNKNOWN_VERSION;

    }

    crl->version++;

    if ((ret = mbedtls_x509_get_sig_alg(&crl->sig_oid, &sig_params1,

                                        &crl->sig_md, &crl->sig_pk,

                                        &crl->sig_opts)) != 0) {

        mbedtls_x509_crl_free(crl);

        return MBEDTLS_ERR_X509_UNKNOWN_SIG_ALG;

    }

    /*

     * issuer               Name

     */

    crl->issuer_raw.p = p;

    if ((ret = mbedtls_asn1_get_tag(&p, end, &len,

                                    MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) != 0) {

        mbedtls_x509_crl_free(crl);

        return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_FORMAT, ret);

    }

    if ((ret = mbedtls_x509_get_name(&p, p + len, &crl->issuer)) != 0) {

        mbedtls_x509_crl_free(crl);

        return ret;

    }

    crl->issuer_raw.len = p - crl->issuer_raw.p;

    /*

     * thisUpdate          Time

     * nextUpdate          Time OPTIONAL

     */

    if ((ret = mbedtls_x509_get_time(&p, end, &crl->this_update)) != 0) {

        mbedtls_x509_crl_free(crl);

        return ret;

    }

    if ((ret = mbedtls_x509_get_time(&p, end, &crl->next_update)) != 0) {

        if (ret != (MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_DATE,

                                      MBEDTLS_ERR_ASN1_UNEXPECTED_TAG)) &&

            ret != (MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_DATE,

                                      MBEDTLS_ERR_ASN1_OUT_OF_DATA))) {

            mbedtls_x509_crl_free(crl);

            return ret;

        }

    }

    /*

     * revokedCertificates    SEQUENCE OF SEQUENCE   {

     *      userCertificate        CertificateSerialNumber,

     *      revocationDate         Time,

     *      crlEntryExtensions     Extensions OPTIONAL

     *                                   -- if present, MUST be v2

     *                        } OPTIONAL

     */

    if ((ret = x509_get_entries(&p, end, &crl->entry)) != 0) {

        mbedtls_x509_crl_free(crl);

        return ret;

    }

    /*

     * crlExtensions          EXPLICIT Extensions OPTIONAL

     *                              -- if present, MUST be v2

     */

    if (crl->version == 2) {

        ret = x509_get_crl_ext(&p, end, &crl->crl_ext);

        if (ret != 0) {

            mbedtls_x509_crl_free(crl);

            return ret;

        }

    }

    if (p != end) {

        mbedtls_x509_crl_free(crl);

        return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_FORMAT,

                                 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH);

    }

    end = crl->raw.p + crl->raw.len;

    /*

     *  signatureAlgorithm   AlgorithmIdentifier,

     *  signatureValue       BIT STRING

     */

    if ((ret = mbedtls_x509_get_alg(&p, end, &sig_oid2, &sig_params2)) != 0) {

        mbedtls_x509_crl_free(crl);

        return ret;

    }

    if (crl->sig_oid.len != sig_oid2.len ||

        memcmp(crl->sig_oid.p, sig_oid2.p, crl->sig_oid.len) != 0 ||

        sig_params1.len != sig_params2.len ||

        (sig_params1.len != 0 &&

         memcmp(sig_params1.p, sig_params2.p, sig_params1.len) != 0)) {

        mbedtls_x509_crl_free(crl);

        return MBEDTLS_ERR_X509_SIG_MISMATCH;

    }

    if ((ret = mbedtls_x509_get_sig(&p, end, &crl->sig)) != 0) {

        mbedtls_x509_crl_free(crl);

        return ret;

    }

    if (p != end) {

        mbedtls_x509_crl_free(crl);

        return MBEDTLS_ERROR_ADD(MBEDTLS_ERR_X509_INVALID_FORMAT,

                                 MBEDTLS_ERR_ASN1_LENGTH_MISMATCH);

    }

    return 0;

}

/*

 * Parse one or more CRLs and add them to the chained list

 */

int mbedtls_x509_crl_parse(mbedtls_x509_crl *chain, const unsigned char *buf, size_t buflen)

{

#if defined(MBEDTLS_PEM_PARSE_C)

    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;

    size_t use_len = 0;

    mbedtls_pem_context pem;

    int is_pem = 0;

    if (chain == NULL || buf == NULL) {

        return MBEDTLS_ERR_X509_BAD_INPUT_DATA;

    }

    do {

        mbedtls_pem_init(&pem);

        // Avoid calling mbedtls_pem_read_buffer() on non-null-terminated

        // string

        if (buflen == 0 || buf[buflen - 1] != '\0') {

            ret = MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT;

        } else {

            ret = mbedtls_pem_read_buffer(&pem,

                                          "-----BEGIN X509 CRL-----",

                                          "-----END X509 CRL-----",

                                          buf, NULL, 0, &use_len);

        }

        if (ret == 0) {

            /*

             * Was PEM encoded

             */

            is_pem = 1;

            buflen -= use_len;

            buf += use_len;

            if ((ret = mbedtls_x509_crl_parse_der(chain,

                                                  pem.buf, pem.buflen)) != 0) {

                mbedtls_pem_free(&pem);

                return ret;

            }

        } else if (is_pem) {

            mbedtls_pem_free(&pem);

            return ret;

        }

        mbedtls_pem_free(&pem);

    }

    /* In the PEM case, buflen is 1 at the end, for the terminated NULL byte.

     * And a valid CRL cannot be less than 1 byte anyway. */

    while (is_pem && buflen > 1);

    if (is_pem) {

        return 0;

    } else

#endif /* MBEDTLS_PEM_PARSE_C */

    return mbedtls_x509_crl_parse_der(chain, buf, buflen);

}

#if defined(MBEDTLS_FS_IO)

/*

 * Load one or more CRLs and add them to the chained list

 */

int mbedtls_x509_crl_parse_file(mbedtls_x509_crl *chain, const char *path)

{

    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;

    size_t n;

    unsigned char *buf;

    if ((ret = mbedtls_pk_load_file(path, &buf, &n)) != 0) {

        return ret;

    }

    ret = mbedtls_x509_crl_parse(chain, buf, n);

    mbedtls_zeroize_and_free(buf, n);

    return ret;

}

#endif /* MBEDTLS_FS_IO */

#if !defined(MBEDTLS_X509_REMOVE_INFO)

/*

 * Return an informational string about the certificate.

 */

#define BEFORE_COLON    14

#define BC              "14"

/*

 * Return an informational string about the CRL.

 */

int mbedtls_x509_crl_info(char *buf, size_t size, const char *prefix,

                          const mbedtls_x509_crl *crl)

{

    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;

    size_t n;

    char *p;

    const mbedtls_x509_crl_entry *entry;

    p = buf;

    n = size;

    ret = mbedtls_snprintf(p, n, "%sCRL version   : %d",

                           prefix, crl->version);

    MBEDTLS_X509_SAFE_SNPRINTF;

    ret = mbedtls_snprintf(p, n, "\n%sissuer name   : ", prefix);

    MBEDTLS_X509_SAFE_SNPRINTF;

    ret = mbedtls_x509_dn_gets(p, n, &crl->issuer);

    MBEDTLS_X509_SAFE_SNPRINTF;

    ret = mbedtls_snprintf(p, n, "\n%sthis update   : " \

                                 "%04d-%02d-%02d %02d:%02d:%02d", prefix,

                           crl->this_update.year, crl->this_update.mon,

                           crl->this_update.day,  crl->this_update.hour,

                           crl->this_update.min,  crl->this_update.sec);

    MBEDTLS_X509_SAFE_SNPRINTF;

    ret = mbedtls_snprintf(p, n, "\n%snext update   : " \

                                 "%04d-%02d-%02d %02d:%02d:%02d", prefix,

                           crl->next_update.year, crl->next_update.mon,

                           crl->next_update.day,  crl->next_update.hour,

                           crl->next_update.min,  crl->next_update.sec);

    MBEDTLS_X509_SAFE_SNPRINTF;

    entry = &crl->entry;

    ret = mbedtls_snprintf(p, n, "\n%sRevoked certificates:",

                           prefix);

    MBEDTLS_X509_SAFE_SNPRINTF;

    while (entry != NULL && entry->raw.len != 0) {

        ret = mbedtls_snprintf(p, n, "\n%sserial number: ",

                               prefix);

        MBEDTLS_X509_SAFE_SNPRINTF;

        ret = mbedtls_x509_serial_gets(p, n, &entry->serial);

        MBEDTLS_X509_SAFE_SNPRINTF;

        ret = mbedtls_snprintf(p, n, " revocation date: " \

                                     "%04d-%02d-%02d %02d:%02d:%02d",

                               entry->revocation_date.year, entry->revocation_date.mon,

                               entry->revocation_date.day,  entry->revocation_date.hour,

                               entry->revocation_date.min,  entry->revocation_date.sec);

        MBEDTLS_X509_SAFE_SNPRINTF;

        entry = entry->next;

    }

    ret = mbedtls_snprintf(p, n, "\n%ssigned using  : ", prefix);

    MBEDTLS_X509_SAFE_SNPRINTF;

    ret = mbedtls_x509_sig_alg_gets(p, n, &crl->sig_oid, crl->sig_pk, crl->sig_md,

                                    crl->sig_opts);

    MBEDTLS_X509_SAFE_SNPRINTF;

    ret = mbedtls_snprintf(p, n, "\n");

    MBEDTLS_X509_SAFE_SNPRINTF;

    return (int) (size - n);

}

#endif /* MBEDTLS_X509_REMOVE_INFO */

/*

 * Initialize a CRL chain

 */

void mbedtls_x509_crl_init(mbedtls_x509_crl *crl)

{

    memset(crl, 0, sizeof(mbedtls_x509_crl));

}

/*

 * Unallocate all CRL data

 */

void mbedtls_x509_crl_free(mbedtls_x509_crl *crl)

{

    mbedtls_x509_crl *crl_cur = crl;

    mbedtls_x509_crl *crl_prv;

    mbedtls_x509_crl_entry *entry_cur;

    mbedtls_x509_crl_entry *entry_prv;

    while (crl_cur != NULL) {

#if defined(MBEDTLS_X509_RSASSA_PSS_SUPPORT)

        mbedtls_free(crl_cur->sig_opts);

#endif

        mbedtls_asn1_free_named_data_list_shallow(crl_cur->issuer.next);

        entry_cur = crl_cur->entry.next;

        while (entry_cur != NULL) {

            entry_prv = entry_cur;

            entry_cur = entry_cur->next;

            mbedtls_zeroize_and_free(entry_prv,

                                     sizeof(mbedtls_x509_crl_entry));

        }

        if (crl_cur->raw.p != NULL) {

            mbedtls_zeroize_and_free(crl_cur->raw.p, crl_cur->raw.len);

        }

        crl_prv = crl_cur;

        crl_cur = crl_cur->next;

        mbedtls_platform_zeroize(crl_prv, sizeof(mbedtls_x509_crl));

        if (crl_prv != crl) {

            mbedtls_free(crl_prv);

        }

    }

}

#endif /* MBEDTLS_X509_CRL_PARSE_C */