diff --git a/include/mbedtls/x509_internal.h b/include/mbedtls/x509_internal.h
new file mode 100644
index 0000000..6fc6fe6
--- /dev/null
+++ b/include/mbedtls/x509_internal.h
@@ -0,0 +1,83 @@
+/**
+ * \file x509_internal.h
+ *
+ * \brief Internal X.509 functions
+ */
+/*
+ *  Copyright (C) 2006-2019, 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)
+ *
+ */
+#ifndef MBEDTLS_X509_INTERNAL_H
+#define MBEDTLS_X509_INTERNAL_H
+
+#include "x509.h"
+
+int mbedtls_x509_get_name( unsigned char *p, size_t len,
+                           mbedtls_x509_name *cur );
+int mbedtls_x509_get_alg_null( unsigned char **p, const unsigned char *end,
+                       mbedtls_x509_buf *alg );
+int mbedtls_x509_get_alg( unsigned char **p, const unsigned char *end,
+                  mbedtls_x509_buf *alg, mbedtls_x509_buf *params );
+#if defined(MBEDTLS_X509_RSASSA_PSS_SUPPORT)
+int mbedtls_x509_get_rsassa_pss_params( const mbedtls_x509_buf *params,
+                                mbedtls_md_type_t *md_alg, mbedtls_md_type_t *mgf_md,
+                                int *salt_len );
+#endif
+int mbedtls_x509_get_sig( unsigned char **p, const unsigned char *end, mbedtls_x509_buf *sig );
+int mbedtls_x509_get_sig_alg_raw( unsigned char **p, unsigned char const *end,
+                                  mbedtls_md_type_t *md_alg,
+                                  mbedtls_pk_type_t *pk_alg,
+                                  void **sig_opts );
+int mbedtls_x509_get_sig_alg( const mbedtls_x509_buf *sig_oid, const mbedtls_x509_buf *sig_params,
+                      mbedtls_md_type_t *md_alg, mbedtls_pk_type_t *pk_alg,
+                      void **sig_opts );
+int mbedtls_x509_get_time( unsigned char **p, const unsigned char *end,
+                   mbedtls_x509_time *t );
+int mbedtls_x509_get_serial( unsigned char **p, const unsigned char *end,
+                     mbedtls_x509_buf *serial );
+int mbedtls_x509_name_cmp_raw( mbedtls_x509_buf_raw const *a,
+                               mbedtls_x509_buf_raw const *b,
+                               int (*check)( void *ctx,
+                                             mbedtls_x509_buf *oid,
+                                             mbedtls_x509_buf *val,
+                                             int next_merged ),
+                               void *check_ctx );
+int mbedtls_x509_memcasecmp( const void *s1, const void *s2,
+                             size_t len1, size_t lend2 );
+int mbedtls_x509_get_ext( unsigned char **p, const unsigned char *end,
+                  mbedtls_x509_buf *ext, int tag );
+
+#if !defined(MBEDTLS_X509_REMOVE_INFO)
+int mbedtls_x509_sig_alg_gets( char *buf, size_t size,
+                       mbedtls_pk_type_t pk_alg, mbedtls_md_type_t md_alg,
+                       const void *sig_opts );
+#endif
+int mbedtls_x509_key_size_helper( char *buf, size_t buf_size, const char *name );
+int mbedtls_x509_string_to_names( mbedtls_asn1_named_data **head, const char *name );
+int mbedtls_x509_set_extension( mbedtls_asn1_named_data **head, const char *oid, size_t oid_len,
+                        int critical, const unsigned char *val,
+                        size_t val_len );
+int mbedtls_x509_write_extensions( unsigned char **p, unsigned char *start,
+                           mbedtls_asn1_named_data *first );
+int mbedtls_x509_write_names( unsigned char **p, unsigned char *start,
+                      mbedtls_asn1_named_data *first );
+int mbedtls_x509_write_sig( unsigned char **p, unsigned char *start,
+                    const char *oid, size_t oid_len,
+                    unsigned char *sig, size_t size );
+
+#endif /* MBEDTLS_X509_INTERNAL_H */