diff --git a/include/mbedtls/asn1write.h b/include/mbedtls/asn1write.h
index f76fc80..40c5d97 100644
--- a/include/mbedtls/asn1write.h
+++ b/include/mbedtls/asn1write.h
@@ -153,6 +153,21 @@
 int mbedtls_asn1_write_int( unsigned char **p, unsigned char *start, int val );
 
 /**
+ * \brief           Write a given string tag and
+ *                  value in ASN.1 format
+ *                  Note: function works backwards in data buffer
+ *
+ * \param p         reference to current position pointer
+ * \param start     start of the buffer (for bounds-checking)
+ * \param tag       the tag to write
+ * \param text      the text to write
+ * \param text_len  length of the text
+ *
+ * \return          the length written or a negative error code
+ */
+int mbedtls_asn1_write_any_string( unsigned char **p, unsigned char *start,
+                                 int tag, const char *text, size_t text_len );
+/**
  * \brief           Write a printable string tag (MBEDTLS_ASN1_PRINTABLE_STRING) and
  *                  value in ASN.1 format
  *                  Note: function works backwards in data buffer
@@ -168,6 +183,21 @@
                                  const char *text, size_t text_len );
 
 /**
+ * \brief           Write a UTF8 string tag (MBEDTLS_ASN1_UTF8_STRING) and
+ *                  value in ASN.1 format
+ *                  Note: function works backwards in data buffer
+ *
+ * \param p         reference to current position pointer
+ * \param start     start of the buffer (for bounds-checking)
+ * \param text      the text to write
+ * \param text_len  length of the text
+ *
+ * \return          the length written or a negative error code
+ */
+int mbedtls_asn1_write_utf8_string( unsigned char **p, unsigned char *start,
+                                 const char *text, size_t text_len );
+
+/**
  * \brief           Write an IA5 string tag (MBEDTLS_ASN1_IA5_STRING) and
  *                  value in ASN.1 format
  *                  Note: function works backwards in data buffer