diff --git a/library/ssl_tls13_client.c b/library/ssl_tls13_client.c
index d024abf..59e42c8 100644
--- a/library/ssl_tls13_client.c
+++ b/library/ssl_tls13_client.c
@@ -1189,8 +1189,6 @@
 static int ssl_tls13_postprocess_server_hello( mbedtls_ssl_context *ssl )
 {
     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
-    mbedtls_ssl_key_set traffic_keys;
-    mbedtls_ssl_transform *transform_handshake = NULL;
     mbedtls_ssl_handshake_params *handshake = ssl->handshake;
 
     /* Determine the key exchange mode:
@@ -1234,50 +1232,21 @@
     ret = mbedtls_ssl_tls13_key_schedule_stage_early( ssl );
     if( ret != 0 )
     {
-        MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_tls13_key_schedule_stage_early_data",
+        MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_tls13_key_schedule_stage_early",
                                ret );
         goto cleanup;
     }
 
-    /* Compute handshake secret */
-    ret = mbedtls_ssl_tls13_key_schedule_stage_handshake( ssl );
+    ret = mbedtls_ssl_tls13_compute_handshake_transform( ssl );
     if( ret != 0 )
     {
-        MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_tls13_derive_master_secret", ret );
-        goto cleanup;
-    }
-
-    /* Next evolution in key schedule: Establish handshake secret and
-     * key material. */
-    ret = mbedtls_ssl_tls13_generate_handshake_keys( ssl, &traffic_keys );
-    if( ret != 0 )
-    {
-        MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_tls13_generate_handshake_keys",
+        MBEDTLS_SSL_DEBUG_RET( 1,
+                               "mbedtls_ssl_tls13_compute_handshake_transform",
                                ret );
         goto cleanup;
     }
 
-    transform_handshake = mbedtls_calloc( 1, sizeof( mbedtls_ssl_transform ) );
-    if( transform_handshake == NULL )
-    {
-        ret = MBEDTLS_ERR_SSL_ALLOC_FAILED;
-        goto cleanup;
-    }
-
-    ret = mbedtls_ssl_tls13_populate_transform( transform_handshake,
-                              ssl->conf->endpoint,
-                              ssl->session_negotiate->ciphersuite,
-                              &traffic_keys,
-                              ssl );
-    if( ret != 0 )
-    {
-        MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_tls13_populate_transform", ret );
-        goto cleanup;
-    }
-
-    handshake->transform_handshake = transform_handshake;
-    mbedtls_ssl_set_inbound_transform( ssl, transform_handshake );
-
+    mbedtls_ssl_set_inbound_transform( ssl, handshake->transform_handshake );
     MBEDTLS_SSL_DEBUG_MSG( 1, ( "Switch to handshake keys for inbound traffic" ) );
     ssl->session_in = ssl->session_negotiate;
 
@@ -1287,16 +1256,13 @@
     mbedtls_ssl_handshake_set_state( ssl, MBEDTLS_SSL_ENCRYPTED_EXTENSIONS );
 
 cleanup:
-
-    mbedtls_platform_zeroize( &traffic_keys, sizeof( traffic_keys ) );
     if( ret != 0 )
     {
-        mbedtls_free( transform_handshake );
-
         MBEDTLS_SSL_PEND_FATAL_ALERT(
             MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE,
             MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE );
     }
+
     return( ret );
 }
 
diff --git a/library/ssl_tls13_keys.c b/library/ssl_tls13_keys.c
index 6559bc9..8ffd9a1 100644
--- a/library/ssl_tls13_keys.c
+++ b/library/ssl_tls13_keys.c
@@ -27,6 +27,7 @@
 #include "mbedtls/hkdf.h"
 #include "mbedtls/debug.h"
 #include "mbedtls/error.h"
+#include "mbedtls/platform.h"
 
 #include "ssl_misc.h"
 #include "ssl_tls13_keys.h"
@@ -1506,8 +1507,62 @@
     /* randbytes is not used again */
     mbedtls_platform_zeroize( ssl->handshake->randbytes,
                               sizeof( ssl->handshake->randbytes ) );
+
     mbedtls_platform_zeroize( transcript, sizeof( transcript ) );
     return( ret );
 }
 
+int mbedtls_ssl_tls13_compute_handshake_transform( mbedtls_ssl_context *ssl )
+{
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
+    mbedtls_ssl_key_set traffic_keys;
+    mbedtls_ssl_transform *transform_handshake = NULL;
+    mbedtls_ssl_handshake_params *handshake = ssl->handshake;
+
+    /* Compute handshake secret */
+    ret = mbedtls_ssl_tls13_key_schedule_stage_handshake( ssl );
+    if( ret != 0 )
+    {
+        MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_tls13_derive_master_secret", ret );
+        goto cleanup;
+    }
+
+    /* Next evolution in key schedule: Establish handshake secret and
+     * key material. */
+    ret = mbedtls_ssl_tls13_generate_handshake_keys( ssl, &traffic_keys );
+    if( ret != 0 )
+    {
+        MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_tls13_generate_handshake_keys",
+                               ret );
+        goto cleanup;
+    }
+
+    transform_handshake = mbedtls_calloc( 1, sizeof( mbedtls_ssl_transform ) );
+    if( transform_handshake == NULL )
+    {
+        ret = MBEDTLS_ERR_SSL_ALLOC_FAILED;
+        goto cleanup;
+    }
+
+    ret = mbedtls_ssl_tls13_populate_transform(
+                                        transform_handshake,
+                                        ssl->conf->endpoint,
+                                        ssl->session_negotiate->ciphersuite,
+                                        &traffic_keys,
+                                        ssl );
+    if( ret != 0 )
+    {
+        MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_tls13_populate_transform", ret );
+        goto cleanup;
+    }
+    handshake->transform_handshake = transform_handshake;
+
+cleanup:
+    mbedtls_platform_zeroize( &traffic_keys, sizeof( traffic_keys ) );
+    if( ret != 0 )
+        mbedtls_free( transform_handshake );
+
+    return( ret );
+}
+
 #endif /* MBEDTLS_SSL_PROTO_TLS1_3 */
diff --git a/library/ssl_tls13_keys.h b/library/ssl_tls13_keys.h
index d56067c..676ebae 100644
--- a/library/ssl_tls13_keys.h
+++ b/library/ssl_tls13_keys.h
@@ -638,6 +638,17 @@
                                              size_t *actual_len,
                                              int which );
 
+/**
+ * \brief Compute TLS 1.3 handshake transform
+ *
+ * \param ssl  The SSL context to operate on. The early secret must have been
+ *             computed.
+ *
+ * \returns    \c 0 on success.
+ * \returns    A negative error code on failure.
+ */
+int mbedtls_ssl_tls13_compute_handshake_transform( mbedtls_ssl_context *ssl );
+
 #endif /* MBEDTLS_SSL_PROTO_TLS1_3 */
 
 #endif /* MBEDTLS_SSL_TLS1_3_KEYS_H */
diff --git a/library/ssl_tls13_server.c b/library/ssl_tls13_server.c
index d06b9a8..b2a5cfc 100644
--- a/library/ssl_tls13_server.c
+++ b/library/ssl_tls13_server.c
@@ -22,10 +22,8 @@
 #if defined(MBEDTLS_SSL_SRV_C) && defined(MBEDTLS_SSL_PROTO_TLS1_3)
 
 #include "mbedtls/debug.h"
-
-#include "ssl_misc.h"
-#include "ssl_tls13_keys.h"
-#include "ssl_debug_helpers.h"
+#include "mbedtls/error.h"
+#include "mbedtls/platform.h"
 
 #if defined(MBEDTLS_ECP_C)
 #include "mbedtls/ecp.h"
@@ -39,6 +37,10 @@
 #define mbedtls_free       free
 #endif /* MBEDTLS_PLATFORM_C */
 
+#include "ssl_misc.h"
+#include "ssl_tls13_keys.h"
+#include "ssl_debug_helpers.h"
+
 /* From RFC 8446:
  *   struct {
  *          ProtocolVersion versions<2..254>;
@@ -1024,6 +1026,26 @@
     return( ret );
 }
 
+static int ssl_tls13_finalize_write_server_hello( mbedtls_ssl_context *ssl )
+{
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
+    ret = mbedtls_ssl_tls13_compute_handshake_transform( ssl );
+    if( ret != 0 )
+    {
+        MBEDTLS_SSL_DEBUG_RET( 1,
+                               "mbedtls_ssl_tls13_compute_handshake_transform",
+                               ret );
+        return( ret );
+    }
+
+    mbedtls_ssl_set_outbound_transform( ssl,
+                                        ssl->handshake->transform_handshake );
+    MBEDTLS_SSL_DEBUG_MSG(
+        3, ( "switching to handshake transform for outbound data" ) );
+
+    return( ret );
+}
+
 static int ssl_tls13_write_server_hello( mbedtls_ssl_context *ssl )
 {
     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
@@ -1047,7 +1069,10 @@
     MBEDTLS_SSL_PROC_CHK( mbedtls_ssl_finish_handshake_msg(
                               ssl, buf_len, msg_len ) );
 
+    MBEDTLS_SSL_PROC_CHK( ssl_tls13_finalize_write_server_hello( ssl ) );
+
     mbedtls_ssl_handshake_set_state( ssl, MBEDTLS_SSL_ENCRYPTED_EXTENSIONS );
+
 cleanup:
 
     MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write server hello" ) );
@@ -1055,6 +1080,78 @@
 }
 
 /*
+ * Handler for MBEDTLS_SSL_ENCRYPTED_EXTENSIONS
+ */
+
+/*
+ * struct {
+ *    Extension extensions<0..2 ^ 16 - 1>;
+ * } EncryptedExtensions;
+ *
+ */
+static int ssl_tls13_write_encrypted_extensions_body( mbedtls_ssl_context *ssl,
+                                                      unsigned char *buf,
+                                                      unsigned char *end,
+                                                      size_t *out_len )
+{
+    unsigned char *p = buf;
+    size_t extensions_len = 0;
+    unsigned char *p_extensions_len;
+
+    *out_len = 0;
+
+    MBEDTLS_SSL_CHK_BUF_PTR( p, end, 2 );
+    p_extensions_len = p;
+    p += 2;
+
+    ((void) ssl);
+
+    extensions_len = ( p - p_extensions_len ) - 2;
+    MBEDTLS_PUT_UINT16_BE( extensions_len, p_extensions_len, 0 );
+
+    *out_len = p - buf;
+
+    MBEDTLS_SSL_DEBUG_BUF( 4, "encrypted extensions", buf, *out_len );
+
+    return( 0 );
+}
+
+static int ssl_tls13_write_encrypted_extensions( mbedtls_ssl_context *ssl )
+{
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
+    unsigned char *buf;
+    size_t buf_len, msg_len;
+
+    MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> write encrypted extensions" ) );
+
+    MBEDTLS_SSL_PROC_CHK( mbedtls_ssl_start_handshake_msg( ssl,
+                       MBEDTLS_SSL_HS_ENCRYPTED_EXTENSIONS, &buf, &buf_len ) );
+
+    MBEDTLS_SSL_PROC_CHK( ssl_tls13_write_encrypted_extensions_body(
+                              ssl, buf, buf + buf_len, &msg_len ) );
+
+    mbedtls_ssl_add_hs_msg_to_checksum(
+        ssl, MBEDTLS_SSL_HS_ENCRYPTED_EXTENSIONS, buf, msg_len );
+
+    MBEDTLS_SSL_PROC_CHK( mbedtls_ssl_finish_handshake_msg(
+                              ssl, buf_len, msg_len ) );
+
+#if defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED)
+    if( mbedtls_ssl_tls13_some_psk_enabled( ssl ) )
+        mbedtls_ssl_handshake_set_state( ssl, MBEDTLS_SSL_SERVER_FINISHED );
+    else
+        mbedtls_ssl_handshake_set_state( ssl, MBEDTLS_SSL_SERVER_CERTIFICATE );
+#else
+    mbedtls_ssl_handshake_set_state( ssl, MBEDTLS_SSL_SERVER_FINISHED );
+#endif
+
+cleanup:
+
+    MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= write encrypted extensions" ) );
+    return( ret );
+}
+
+/*
  * TLS 1.3 State Machine -- server side
  */
 int mbedtls_ssl_tls13_handshake_server_step( mbedtls_ssl_context *ssl )
@@ -1089,6 +1186,15 @@
             ret = ssl_tls13_write_server_hello( ssl );
             break;
 
+        case MBEDTLS_SSL_ENCRYPTED_EXTENSIONS:
+            ret = ssl_tls13_write_encrypted_extensions( ssl );
+            if( ret != 0 )
+            {
+                MBEDTLS_SSL_DEBUG_RET( 1, "ssl_tls13_write_encrypted_extensions", ret );
+                return( ret );
+            }
+            break;
+
         default:
             MBEDTLS_SSL_DEBUG_MSG( 1, ( "invalid state %d", ssl->state ) );
             return( MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE );
diff --git a/tests/ssl-opt.sh b/tests/ssl-opt.sh
index dcee5df..07ad1b3 100755
--- a/tests/ssl-opt.sh
+++ b/tests/ssl-opt.sh
@@ -11307,6 +11307,7 @@
             -s "tls13 server state: MBEDTLS_SSL_CLIENT_HELLO" \
             -s "tls13 server state: MBEDTLS_SSL_SERVER_HELLO" \
             -s "tls13 server state: MBEDTLS_SSL_ENCRYPTED_EXTENSIONS" \
+            -s "tls13 server state: MBEDTLS_SSL_SERVER_CERTIFICATE" \
             -s "SSL - The requested feature is not available" \
             -s "=> parse client hello" \
             -s "<= parse client hello"
@@ -11323,6 +11324,7 @@
             -s "tls13 server state: MBEDTLS_SSL_CLIENT_HELLO" \
             -s "tls13 server state: MBEDTLS_SSL_SERVER_HELLO" \
             -s "tls13 server state: MBEDTLS_SSL_ENCRYPTED_EXTENSIONS" \
+            -s "tls13 server state: MBEDTLS_SSL_SERVER_CERTIFICATE" \
             -s "SSL - The requested feature is not available" \
             -s "=> parse client hello" \
             -s "<= parse client hello"
@@ -11338,7 +11340,8 @@
             -s "tls13 server state: MBEDTLS_SSL_CLIENT_HELLO" \
             -s "tls13 server state: MBEDTLS_SSL_SERVER_HELLO" \
             -s "tls13 server state: MBEDTLS_SSL_ENCRYPTED_EXTENSIONS" \
-            -c "client state: MBEDTLS_SSL_ENCRYPTED_EXTENSIONS" \
+            -s "tls13 server state: MBEDTLS_SSL_SERVER_CERTIFICATE" \
+            -c "client state: MBEDTLS_SSL_CERTIFICATE_REQUEST" \
             -s "SSL - The requested feature is not available" \
             -s "=> parse client hello" \
             -s "<= parse client hello"