diff --git a/library/x509_crl.c b/library/x509_crl.c
new file mode 100644
index 0000000..8450f87
--- /dev/null
+++ b/library/x509_crl.c
@@ -0,0 +1,773 @@
+/*
+ *  X.509 Certidicate Revocation List (CRL) parsing
+ *
+ *  Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
+ *  SPDX-License-Identifier: Apache-2.0
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License"); you may
+ *  not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ *
+ *  This file is part of mbed TLS (https://tls.mbed.org)
+ */
+/*
+ *  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
+ */
+
+#if !defined(MBEDTLS_CONFIG_FILE)
+#include "mbedtls/config.h"
+#else
+#include MBEDTLS_CONFIG_FILE
+#endif
+
+#if defined(MBEDTLS_X509_CRL_PARSE_C)
+
+#include "mbedtls/x509_crl.h"
+#include "mbedtls/oid.h"
+#include "mbedtls/platform_util.h"
+
+#include <string.h>
+
+#if defined(MBEDTLS_PEM_PARSE_C)
+#include "mbedtls/pem.h"
+#endif
+
+#if defined(MBEDTLS_PLATFORM_C)
+#include "mbedtls/platform.h"
+#else
+#include <stdlib.h>
+#include <stdio.h>
+#define mbedtls_free       free
+#define mbedtls_calloc    calloc
+#define mbedtls_snprintf   snprintf
+#endif
+
+#if defined(_WIN32) && !defined(EFIX64) && !defined(EFI32)
+#include <windows.h>
+#else
+#include <time.h>
+#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;
+
+    if( ( ret = mbedtls_asn1_get_int( p, end, ver ) ) != 0 )
+    {
+        if( ret == MBEDTLS_ERR_ASN1_UNEXPECTED_TAG )
+        {
+            *ver = 0;
+            return( 0 );
+        }
+
+        return( 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;
+
+    /*
+     * crlExtensions           [0]  EXPLICIT Extensions OPTIONAL
+     *                              -- if present, version MUST be v2
+     */
+    if( ( ret = mbedtls_x509_get_ext( p, end, ext, 0 ) ) != 0 )
+    {
+        if( ret == MBEDTLS_ERR_ASN1_UNEXPECTED_TAG )
+            return( 0 );
+
+        return( ret );
+    }
+
+    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_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_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_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_ERR_X509_INVALID_EXTENSIONS + ret );
+
+        /* Ignore data so far and just check its length */
+        *p += len;
+        if( *p != end_ext_data )
+            return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
+                    MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
+
+        /* Abort on (unsupported) critical extensions */
+        if( is_critical )
+            return( MBEDTLS_ERR_X509_INVALID_EXTENSIONS +
+                    MBEDTLS_ERR_ASN1_UNEXPECTED_TAG );
+    }
+
+    if( *p != end )
+        return( 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;
+    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_ERR_X509_INVALID_EXTENSIONS + ret );
+    }
+
+    end = *p + ext->len;
+
+    if( end != *p + ext->len )
+        return( 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_ERR_X509_INVALID_EXTENSIONS + ret );
+
+        *p += len;
+    }
+
+    if( *p != end )
+        return( 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;
+    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;
+
+        if( ( ret = mbedtls_asn1_get_tag( p, end, &len2,
+                MBEDTLS_ASN1_SEQUENCE | MBEDTLS_ASN1_CONSTRUCTED ) ) != 0 )
+        {
+            return( ret );
+        }
+
+        cur_entry->raw.tag = **p;
+        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;
+    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_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_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_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_ERR_X509_INVALID_DATE +
+                        MBEDTLS_ERR_ASN1_UNEXPECTED_TAG ) &&
+            ret != ( 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_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_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;
+    size_t use_len;
+    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;
+    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_platform_zeroize( buf, n );
+    mbedtls_free( buf );
+
+    return( ret );
+}
+#endif /* MBEDTLS_FS_IO */
+
+/*
+ * 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;
+    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 ) );
+}
+
+/*
+ * 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_name *name_cur;
+    mbedtls_x509_name *name_prv;
+    mbedtls_x509_crl_entry *entry_cur;
+    mbedtls_x509_crl_entry *entry_prv;
+
+    if( crl == NULL )
+        return;
+
+    do
+    {
+#if defined(MBEDTLS_X509_RSASSA_PSS_SUPPORT)
+        mbedtls_free( crl_cur->sig_opts );
+#endif
+
+        name_cur = crl_cur->issuer.next;
+        while( name_cur != NULL )
+        {
+            name_prv = name_cur;
+            name_cur = name_cur->next;
+            mbedtls_platform_zeroize( name_prv, sizeof( mbedtls_x509_name ) );
+            mbedtls_free( name_prv );
+        }
+
+        entry_cur = crl_cur->entry.next;
+        while( entry_cur != NULL )
+        {
+            entry_prv = entry_cur;
+            entry_cur = entry_cur->next;
+            mbedtls_platform_zeroize( entry_prv,
+                                      sizeof( mbedtls_x509_crl_entry ) );
+            mbedtls_free( entry_prv );
+        }
+
+        if( crl_cur->raw.p != NULL )
+        {
+            mbedtls_platform_zeroize( crl_cur->raw.p, crl_cur->raw.len );
+            mbedtls_free( crl_cur->raw.p );
+        }
+
+        crl_cur = crl_cur->next;
+    }
+    while( crl_cur != NULL );
+
+    crl_cur = crl;
+    do
+    {
+        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 );
+    }
+    while( crl_cur != NULL );
+}
+
+#endif /* MBEDTLS_X509_CRL_PARSE_C */