Address review feedback

Signed-off-by: Dave Rodgman <dave.rodgman@arm.com>
diff --git a/library/ssl_cli.c b/library/ssl_cli.c
index 558755d..fc791d6 100644
--- a/library/ssl_cli.c
+++ b/library/ssl_cli.c
@@ -1389,8 +1389,8 @@
             mbedtls_ssl_send_alert_message(
                 ssl,
                 MBEDTLS_SSL_ALERT_LEVEL_FATAL,
-                MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER );
-            return( MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER );
+                MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
+            return( MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE );
         }
     }
     else
@@ -1403,8 +1403,8 @@
             mbedtls_ssl_send_alert_message(
                 ssl,
                 MBEDTLS_SSL_ALERT_LEVEL_FATAL,
-                MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER );
-            return( MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER );
+                MBEDTLS_SSL_ALERT_MSG_HANDSHAKE_FAILURE );
+            return( MBEDTLS_ERR_SSL_HANDSHAKE_FAILURE );
         }
 
         ssl->secure_renegotiation = MBEDTLS_SSL_SECURE_RENEGOTIATION;
@@ -1453,7 +1453,7 @@
     {
         MBEDTLS_SSL_DEBUG_MSG( 1, ( "CID extension unexpected" ) );
         mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,
-                                        MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER );
+                                        MBEDTLS_SSL_ALERT_MSG_UNSUPPORTED_EXT );
         return( MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER );
     }
 
@@ -1508,7 +1508,7 @@
         mbedtls_ssl_send_alert_message(
             ssl,
             MBEDTLS_SSL_ALERT_LEVEL_FATAL,
-            MBEDTLS_SSL_ALERT_MSG_ILLEGAL_PARAMETER );
+            MBEDTLS_SSL_ALERT_MSG_UNSUPPORTED_EXT );
         return( MBEDTLS_ERR_SSL_ILLEGAL_PARAMETER );
     }