initial commit, 4.5 stable

thirdparty/mbedtls/library/x509_crl.c

@@ -0,0 +1,713 @@
+/*
+ *  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 "x509_internal.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 = (size_t) (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 = (size_t) (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 */