Add 1/n-1 record splitting

include/polarssl/check_config.h

@@ -263,6 +263,11 @@
 #error "POLARSSL_SSL_SESSION_TICKETS_C defined, but not all prerequisites"
 #endif
 
+#if defined(POLARSSL_SSL_CBC_RECORD_SPLITTING) && \
+    !defined(POLARSSL_SSL_PROTO_SSL3) && !defined(POLARSSL_SSL_PROTO_TLS1)
+#error "POLARSSL_SSL_CBC_RECORD_SPLITTING defined, but not all prerequisites"
+#endif
+
 #if defined(POLARSSL_SSL_SERVER_NAME_INDICATION) && \
         !defined(POLARSSL_X509_CRT_PARSE_C)
 #error "POLARSSL_SSL_SERVER_NAME_INDICATION defined, but not all prerequisites"

include/polarssl/config.h

@@ -821,6 +821,18 @@
  */
 //#define POLARSSL_SSL_HW_RECORD_ACCEL
 
+/**
+ * \def POLARSSL_SSL_CBC_RECORD_SPLITTING
+ *
+ * Enable 1/n-1 record splitting for CBC mode in SSLv3 and TLS 1.0.
+ *
+ * This is a countermeasure to the BEAST attack, which also minimizes the risk
+ * of interoperability issues compared to sending 0-length records.
+ *
+ * Comment this macro to disable 1/n-1 record splitting.
+ */
+#define POLARSSL_SSL_CBC_RECORD_SPLITTING
+
 /**
  * \def POLARSSL_SSL_SRV_SUPPORT_SSLV2_CLIENT_HELLO
  *

include/polarssl/ssl.h

@@ -784,6 +784,9 @@ struct _ssl_context
 #if defined(POLARSSL_SSL_MAX_FRAGMENT_LENGTH)
     unsigned char mfl_code;     /*!< MaxFragmentLength chosen by us   */
 #endif /* POLARSSL_SSL_MAX_FRAGMENT_LENGTH */
+#if defined(POLARSSL_SSL_CBC_RECORD_SPLITTING)
+    unsigned char split_done;  /*!< flag for record splitting        */
+#endif
 
     /*
      * PKI layer