diff --git a/library/ssl_tls13_generic.c b/library/ssl_tls13_generic.c
index dab98a3..6623e7f 100644
--- a/library/ssl_tls13_generic.c
+++ b/library/ssl_tls13_generic.c
@@ -72,68 +72,6 @@
     return( ret );
 }
 
-int mbedtls_ssl_tls13_start_handshake_msg( mbedtls_ssl_context *ssl,
-                                           unsigned hs_type,
-                                           unsigned char **buf,
-                                           size_t *buf_len )
-{
-    /*
-     * Reserve 4 bytes for hanshake header. ( Section 4,RFC 8446 )
-     *    ...
-     *    HandshakeType msg_type;
-     *    uint24 length;
-     *    ...
-     */
-    *buf = ssl->out_msg + 4;
-    *buf_len = MBEDTLS_SSL_OUT_CONTENT_LEN - 4;
-
-    ssl->out_msgtype = MBEDTLS_SSL_MSG_HANDSHAKE;
-    ssl->out_msg[0]  = hs_type;
-
-    return( 0 );
-}
-
-int mbedtls_ssl_tls13_finish_handshake_msg( mbedtls_ssl_context *ssl,
-                                            size_t buf_len,
-                                            size_t msg_len )
-{
-    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
-    size_t msg_with_header_len;
-    ((void) buf_len);
-
-    /* Add reserved 4 bytes for handshake header */
-    msg_with_header_len = msg_len + 4;
-    ssl->out_msglen = msg_with_header_len;
-    MBEDTLS_SSL_PROC_CHK( mbedtls_ssl_write_handshake_msg_ext( ssl, 0, 0 ) );
-
-cleanup:
-    return( ret );
-}
-
-void mbedtls_ssl_tls13_add_hs_msg_to_checksum( mbedtls_ssl_context *ssl,
-                                               unsigned hs_type,
-                                               unsigned char const *msg,
-                                               size_t msg_len )
-{
-    mbedtls_ssl_tls13_add_hs_hdr_to_checksum( ssl, hs_type, msg_len );
-    ssl->handshake->update_checksum( ssl, msg, msg_len );
-}
-
-void mbedtls_ssl_tls13_add_hs_hdr_to_checksum( mbedtls_ssl_context *ssl,
-                                               unsigned hs_type,
-                                               size_t total_hs_len )
-{
-    unsigned char hs_hdr[4];
-
-    /* Build HS header for checksum update. */
-    hs_hdr[0] = MBEDTLS_BYTE_0( hs_type );
-    hs_hdr[1] = MBEDTLS_BYTE_2( total_hs_len );
-    hs_hdr[2] = MBEDTLS_BYTE_1( total_hs_len );
-    hs_hdr[3] = MBEDTLS_BYTE_0( total_hs_len );
-
-    ssl->handshake->update_checksum( ssl, hs_hdr, sizeof( hs_hdr ) );
-}
-
 #if defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED)
 /* mbedtls_ssl_tls13_parse_sig_alg_ext()
  *
@@ -479,8 +417,8 @@
     MBEDTLS_SSL_PROC_CHK( ssl_tls13_parse_certificate_verify( ssl, buf,
                             buf + buf_len, verify_buffer, verify_buffer_len ) );
 
-    mbedtls_ssl_tls13_add_hs_msg_to_checksum( ssl,
-                        MBEDTLS_SSL_HS_CERTIFICATE_VERIFY, buf, buf_len );
+    mbedtls_ssl_add_hs_msg_to_checksum( ssl, MBEDTLS_SSL_HS_CERTIFICATE_VERIFY,
+                                        buf, buf_len );
 
 cleanup:
 
@@ -796,8 +734,8 @@
     /* Validate the certificate chain and set the verification results. */
     MBEDTLS_SSL_PROC_CHK( ssl_tls13_validate_certificate( ssl ) );
 
-    mbedtls_ssl_tls13_add_hs_msg_to_checksum( ssl, MBEDTLS_SSL_HS_CERTIFICATE,
-                                              buf, buf_len );
+    mbedtls_ssl_add_hs_msg_to_checksum( ssl, MBEDTLS_SSL_HS_CERTIFICATE,
+                                        buf, buf_len );
 
 cleanup:
 
@@ -904,7 +842,7 @@
 
     MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write certificate" ) );
 
-    MBEDTLS_SSL_PROC_CHK( mbedtls_ssl_tls13_start_handshake_msg( ssl,
+    MBEDTLS_SSL_PROC_CHK( mbedtls_ssl_start_handshake_msg( ssl,
                           MBEDTLS_SSL_HS_CERTIFICATE, &buf, &buf_len ) );
 
     MBEDTLS_SSL_PROC_CHK( ssl_tls13_write_certificate_body( ssl,
@@ -912,12 +850,10 @@
                                                             buf + buf_len,
                                                             &msg_len ) );
 
-    mbedtls_ssl_tls13_add_hs_msg_to_checksum( ssl,
-                                              MBEDTLS_SSL_HS_CERTIFICATE,
-                                              buf,
-                                              msg_len );
+    mbedtls_ssl_add_hs_msg_to_checksum( ssl, MBEDTLS_SSL_HS_CERTIFICATE,
+                                        buf, msg_len );
 
-    MBEDTLS_SSL_PROC_CHK( mbedtls_ssl_tls13_finish_handshake_msg(
+    MBEDTLS_SSL_PROC_CHK( mbedtls_ssl_finish_handshake_msg(
                               ssl, buf_len, msg_len ) );
 cleanup:
 
@@ -1161,16 +1097,16 @@
 
     MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write certificate verify" ) );
 
-    MBEDTLS_SSL_PROC_CHK( mbedtls_ssl_tls13_start_handshake_msg( ssl,
+    MBEDTLS_SSL_PROC_CHK( mbedtls_ssl_start_handshake_msg( ssl,
                 MBEDTLS_SSL_HS_CERTIFICATE_VERIFY, &buf, &buf_len ) );
 
     MBEDTLS_SSL_PROC_CHK( ssl_tls13_write_certificate_verify_body(
                                 ssl, buf, buf + buf_len, &msg_len ) );
 
-    mbedtls_ssl_tls13_add_hs_msg_to_checksum(
-        ssl, MBEDTLS_SSL_HS_CERTIFICATE_VERIFY, buf, msg_len );
+    mbedtls_ssl_add_hs_msg_to_checksum( ssl, MBEDTLS_SSL_HS_CERTIFICATE_VERIFY,
+                                        buf, msg_len );
 
-    MBEDTLS_SSL_PROC_CHK( mbedtls_ssl_tls13_finish_handshake_msg(
+    MBEDTLS_SSL_PROC_CHK( mbedtls_ssl_finish_handshake_msg(
                                 ssl, buf_len, msg_len ) );
 
 cleanup:
@@ -1340,8 +1276,8 @@
                                               MBEDTLS_SSL_HS_FINISHED,
                                               &buf, &buf_len ) );
     MBEDTLS_SSL_PROC_CHK( ssl_tls13_parse_finished_message( ssl, buf, buf + buf_len ) );
-    mbedtls_ssl_tls13_add_hs_msg_to_checksum(
-        ssl, MBEDTLS_SSL_HS_FINISHED, buf, buf_len );
+    mbedtls_ssl_add_hs_msg_to_checksum( ssl, MBEDTLS_SSL_HS_FINISHED,
+                                        buf, buf_len );
     MBEDTLS_SSL_PROC_CHK( ssl_tls13_postprocess_finished_message( ssl ) );
 
 cleanup:
@@ -1418,19 +1354,18 @@
 
     MBEDTLS_SSL_PROC_CHK( ssl_tls13_prepare_finished_message( ssl ) );
 
-    MBEDTLS_SSL_PROC_CHK( mbedtls_ssl_tls13_start_handshake_msg( ssl,
+    MBEDTLS_SSL_PROC_CHK( mbedtls_ssl_start_handshake_msg( ssl,
                               MBEDTLS_SSL_HS_FINISHED, &buf, &buf_len ) );
 
     MBEDTLS_SSL_PROC_CHK( ssl_tls13_write_finished_message_body(
                               ssl, buf, buf + buf_len, &msg_len ) );
 
-    mbedtls_ssl_tls13_add_hs_msg_to_checksum( ssl, MBEDTLS_SSL_HS_FINISHED,
-                                              buf, msg_len );
+    mbedtls_ssl_add_hs_msg_to_checksum( ssl, MBEDTLS_SSL_HS_FINISHED,
+                                        buf, msg_len );
 
     MBEDTLS_SSL_PROC_CHK( ssl_tls13_finalize_finished_message( ssl ) );
-    MBEDTLS_SSL_PROC_CHK( mbedtls_ssl_tls13_finish_handshake_msg( ssl,
-                                              buf_len, msg_len ) );
-
+    MBEDTLS_SSL_PROC_CHK( mbedtls_ssl_finish_handshake_msg(
+                              ssl, buf_len, msg_len ) );
 cleanup:
 
     MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write finished message" ) );