Merge support for enabling / disabling renegotiation support at compile-time
diff --git a/library/ssl_cli.c b/library/ssl_cli.c
index 0db9e23..cf8e46c 100644
--- a/library/ssl_cli.c
+++ b/library/ssl_cli.c
@@ -114,6 +114,7 @@
 }
 #endif /* POLARSSL_SSL_SERVER_NAME_INDICATION */
 
+#if defined(POLARSSL_SSL_RENEGOTIATION)
 static void ssl_write_renegotiation_ext( ssl_context *ssl,
                                          unsigned char *buf,
                                          size_t *olen )
@@ -141,6 +142,7 @@
 
     *olen = 5 + ssl->verify_data_len;
 }
+#endif /* POLARSSL_SSL_RENEGOTIATION */
 
 /*
  * Only if we handle at least one key exchange that needs signatures.
@@ -521,7 +523,9 @@
         return( POLARSSL_ERR_SSL_NO_RNG );
     }
 
+#if defined(POLARSSL_SSL_RENEGOTIATION)
     if( ssl->renegotiation == SSL_INITIAL_HANDSHAKE )
+#endif
     {
         ssl->major_ver = ssl->min_major_ver;
         ssl->minor_ver = ssl->min_minor_ver;
@@ -585,7 +589,10 @@
      */
     n = ssl->session_negotiate->length;
 
-    if( ssl->renegotiation != SSL_INITIAL_HANDSHAKE || n < 16 || n > 32 ||
+    if( n < 16 || n > 32 ||
+#if defined(POLARSSL_SSL_RENEGOTIATION)
+        ssl->renegotiation != SSL_INITIAL_HANDSHAKE ||
+#endif
         ssl->handshake->resume == 0 )
     {
         n = 0;
@@ -596,8 +603,10 @@
      * RFC 5077 section 3.4: "When presenting a ticket, the client MAY
      * generate and include a Session ID in the TLS ClientHello."
      */
-    if( ssl->renegotiation == SSL_INITIAL_HANDSHAKE &&
-        ssl->session_negotiate->ticket != NULL &&
+#if defined(POLARSSL_SSL_RENEGOTIATION)
+    if( ssl->renegotiation == SSL_INITIAL_HANDSHAKE )
+#endif
+    if( ssl->session_negotiate->ticket != NULL &&
         ssl->session_negotiate->ticket_len != 0 )
     {
         ret = ssl->f_rng( ssl->p_rng, ssl->session_negotiate->id, 32 );
@@ -627,7 +636,9 @@
     /*
      * Add TLS_EMPTY_RENEGOTIATION_INFO_SCSV
      */
+#if defined(POLARSSL_SSL_RENEGOTIATION)
     if( ssl->renegotiation == SSL_INITIAL_HANDSHAKE )
+#endif
     {
         *p++ = (unsigned char)( SSL_EMPTY_RENEGOTIATION_INFO >> 8 );
         *p++ = (unsigned char)( SSL_EMPTY_RENEGOTIATION_INFO      );
@@ -693,8 +704,10 @@
     ext_len += olen;
 #endif
 
+#if defined(POLARSSL_SSL_RENEGOTIATION)
     ssl_write_renegotiation_ext( ssl, p + 2 + ext_len, &olen );
     ext_len += olen;
+#endif
 
 #if defined(POLARSSL_SSL_PROTO_TLS1_2) && \
     defined(POLARSSL_KEY_EXCHANGE__WITH_CERT__ENABLED)
@@ -740,6 +753,9 @@
     ext_len += olen;
 #endif
 
+    /* olen unused if all extensions are disabled */
+    ((void) olen);
+
     SSL_DEBUG_MSG( 3, ( "client hello, total extension length: %d",
                    ext_len ) );
 
@@ -773,21 +789,8 @@
 {
     int ret;
 
-    if( ssl->renegotiation == SSL_INITIAL_HANDSHAKE )
-    {
-        if( len != 1 || buf[0] != 0x0 )
-        {
-            SSL_DEBUG_MSG( 1, ( "non-zero length renegotiated connection field" ) );
-
-            if( ( ret = ssl_send_fatal_handshake_failure( ssl ) ) != 0 )
-                return( ret );
-
-            return( POLARSSL_ERR_SSL_BAD_HS_SERVER_HELLO );
-        }
-
-        ssl->secure_renegotiation = SSL_SECURE_RENEGOTIATION;
-    }
-    else
+#if defined(POLARSSL_SSL_RENEGOTIATION)
+    if( ssl->renegotiation != SSL_INITIAL_HANDSHAKE )
     {
         /* Check verify-data in constant-time. The length OTOH is no secret */
         if( len    != 1 + ssl->verify_data_len * 2 ||
@@ -797,7 +800,7 @@
             safer_memcmp( buf + 1 + ssl->verify_data_len,
                           ssl->peer_verify_data, ssl->verify_data_len ) != 0 )
         {
-            SSL_DEBUG_MSG( 1, ( "non-matching renegotiated connection field" ) );
+            SSL_DEBUG_MSG( 1, ( "non-matching renegotiation info" ) );
 
             if( ( ret = ssl_send_fatal_handshake_failure( ssl ) ) != 0 )
                 return( ret );
@@ -805,6 +808,21 @@
             return( POLARSSL_ERR_SSL_BAD_HS_SERVER_HELLO );
         }
     }
+    else
+#endif /* POLARSSL_SSL_RENEGOTIATION */
+    {
+        if( len != 1 || buf[0] != 0x00 )
+        {
+            SSL_DEBUG_MSG( 1, ( "non-zero length renegotiation info" ) );
+
+            if( ( ret = ssl_send_fatal_handshake_failure( ssl ) ) != 0 )
+                return( ret );
+
+            return( POLARSSL_ERR_SSL_BAD_HS_SERVER_HELLO );
+        }
+
+        ssl->secure_renegotiation = SSL_SECURE_RENEGOTIATION;
+    }
 
     return( 0 );
 }
@@ -996,7 +1014,9 @@
     size_t n;
     size_t ext_len;
     unsigned char *buf, *ext;
+#if defined(POLARSSL_SSL_RENEGOTIATION)
     int renegotiation_info_seen = 0;
+#endif
     int handshake_failure = 0;
 #if defined(POLARSSL_DEBUG_C)
     uint32_t t;
@@ -1021,6 +1041,7 @@
 
     if( ssl->in_msgtype != SSL_MSG_HANDSHAKE )
     {
+#if defined(POLARSSL_SSL_RENEGOTIATION)
         if( ssl->renegotiation == SSL_RENEGOTIATION )
         {
             ssl->renego_records_seen++;
@@ -1036,6 +1057,7 @@
             SSL_DEBUG_MSG( 1, ( "non-handshake message during renego" ) );
             return( POLARSSL_ERR_SSL_WAITING_SERVER_HELLO_RENEGO );
         }
+#endif /* POLARSSL_SSL_RENEGOTIATION */
 
         SSL_DEBUG_MSG( 1, ( "bad server hello message" ) );
         return( POLARSSL_ERR_SSL_UNEXPECTED_MESSAGE );
@@ -1144,8 +1166,10 @@
     /*
      * Check if the session can be resumed
      */
-    if( ssl->renegotiation != SSL_INITIAL_HANDSHAKE ||
-        ssl->handshake->resume == 0 || n == 0 ||
+    if( ssl->handshake->resume == 0 || n == 0 ||
+#if defined(POLARSSL_SSL_RENEGOTIATION)
+        ssl->renegotiation != SSL_INITIAL_HANDSHAKE ||
+#endif
         ssl->session_negotiate->ciphersuite != i ||
         ssl->session_negotiate->compression != comp ||
         ssl->session_negotiate->length != n ||
@@ -1226,7 +1250,9 @@
         {
         case TLS_EXT_RENEGOTIATION_INFO:
             SSL_DEBUG_MSG( 3, ( "found renegotiation extension" ) );
+#if defined(POLARSSL_SSL_RENEGOTIATION)
             renegotiation_info_seen = 1;
+#endif
 
             if( ( ret = ssl_parse_renegotiation_info( ssl, ext + 4,
                                                       ext_size ) ) != 0 )
@@ -1346,6 +1372,7 @@
         SSL_DEBUG_MSG( 1, ( "legacy renegotiation, breaking off handshake" ) );
         handshake_failure = 1;
     }
+#if defined(POLARSSL_SSL_RENEGOTIATION)
     else if( ssl->renegotiation == SSL_RENEGOTIATION &&
              ssl->secure_renegotiation == SSL_SECURE_RENEGOTIATION &&
              renegotiation_info_seen == 0 )
@@ -1367,6 +1394,7 @@
         SSL_DEBUG_MSG( 1, ( "renegotiation_info extension present (legacy)" ) );
         handshake_failure = 1;
     }
+#endif /* POLARSSL_SSL_RENEGOTIATION */
 
     if( handshake_failure == 1 )
     {
diff --git a/library/ssl_srv.c b/library/ssl_srv.c
index 7bcec57..4fac0e4 100644
--- a/library/ssl_srv.c
+++ b/library/ssl_srv.c
@@ -431,11 +431,29 @@
 {
     int ret;
 
-    if( ssl->renegotiation == SSL_INITIAL_HANDSHAKE )
+#if defined(POLARSSL_SSL_RENEGOTIATION)
+    if( ssl->renegotiation != SSL_INITIAL_HANDSHAKE )
+    {
+        /* Check verify-data in constant-time. The length OTOH is no secret */
+        if( len    != 1 + ssl->verify_data_len ||
+            buf[0] !=     ssl->verify_data_len ||
+            safer_memcmp( buf + 1, ssl->peer_verify_data,
+                          ssl->verify_data_len ) != 0 )
+        {
+            SSL_DEBUG_MSG( 1, ( "non-matching renegotiation info" ) );
+
+            if( ( ret = ssl_send_fatal_handshake_failure( ssl ) ) != 0 )
+                return( ret );
+
+            return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
+        }
+    }
+    else
+#endif /* POLARSSL_SSL_RENEGOTIATION */
     {
         if( len != 1 || buf[0] != 0x0 )
         {
-            SSL_DEBUG_MSG( 1, ( "non-zero length renegotiated connection field" ) );
+            SSL_DEBUG_MSG( 1, ( "non-zero length renegotiation info" ) );
 
             if( ( ret = ssl_send_fatal_handshake_failure( ssl ) ) != 0 )
                 return( ret );
@@ -445,22 +463,6 @@
 
         ssl->secure_renegotiation = SSL_SECURE_RENEGOTIATION;
     }
-    else
-    {
-        /* Check verify-data in constant-time. The length OTOH is no secret */
-        if( len    != 1 + ssl->verify_data_len ||
-            buf[0] !=     ssl->verify_data_len ||
-            safer_memcmp( buf + 1, ssl->peer_verify_data,
-                          ssl->verify_data_len ) != 0 )
-        {
-            SSL_DEBUG_MSG( 1, ( "non-matching renegotiated connection field" ) );
-
-            if( ( ret = ssl_send_fatal_handshake_failure( ssl ) ) != 0 )
-                return( ret );
-
-            return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
-        }
-    }
 
     return( 0 );
 }
@@ -701,11 +703,13 @@
     if( len == 0 )
         return( 0 );
 
+#if defined(POLARSSL_SSL_RENEGOTIATION)
     if( ssl->renegotiation != SSL_INITIAL_HANDSHAKE )
     {
         SSL_DEBUG_MSG( 3, ( "ticket rejected: renegotiating" ) );
         return( 0 );
     }
+#endif /* POLARSSL_SSL_RENEGOTIATION */
 
     /*
      * Failures are ok: just ignore the ticket and proceed.
@@ -941,6 +945,7 @@
 
     SSL_DEBUG_MSG( 2, ( "=> parse client hello v2" ) );
 
+#if defined(POLARSSL_SSL_RENEGOTIATION)
     if( ssl->renegotiation != SSL_INITIAL_HANDSHAKE )
     {
         SSL_DEBUG_MSG( 1, ( "client hello v2 illegal for renegotiation" ) );
@@ -950,6 +955,7 @@
 
         return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
     }
+#endif /* POLARSSL_SSL_RENEGOTIATION */
 
     buf = ssl->in_hdr;
 
@@ -1086,15 +1092,18 @@
         if( p[0] == 0 && p[1] == 0 && p[2] == SSL_EMPTY_RENEGOTIATION_INFO )
         {
             SSL_DEBUG_MSG( 3, ( "received TLS_EMPTY_RENEGOTIATION_INFO " ) );
+#if defined(POLARSSL_SSL_RENEGOTIATION)
             if( ssl->renegotiation == SSL_RENEGOTIATION )
             {
-                SSL_DEBUG_MSG( 1, ( "received RENEGOTIATION SCSV during renegotiation" ) );
+                SSL_DEBUG_MSG( 1, ( "received RENEGOTIATION SCSV "
+                                    "during renegotiation" ) );
 
                 if( ( ret = ssl_send_fatal_handshake_failure( ssl ) ) != 0 )
                     return( ret );
 
                 return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
             }
+#endif /* POLARSSL_SSL_RENEGOTIATION */
             ssl->secure_renegotiation = SSL_SECURE_RENEGOTIATION;
             break;
         }
@@ -1191,15 +1200,19 @@
     unsigned int comp_len;
     unsigned int ext_len = 0;
     unsigned char *buf, *p, *ext;
+#if defined(POLARSSL_SSL_RENEGOTIATION)
     int renegotiation_info_seen = 0;
+#endif
     int handshake_failure = 0;
     const int *ciphersuites;
     const ssl_ciphersuite_t *ciphersuite_info;
 
     SSL_DEBUG_MSG( 2, ( "=> parse client hello" ) );
 
-    if( ssl->renegotiation == SSL_INITIAL_HANDSHAKE &&
-        ( ret = ssl_fetch_input( ssl, 5 ) ) != 0 )
+#if defined(POLARSSL_SSL_RENEGOTIATION)
+    if( ssl->renegotiation == SSL_INITIAL_HANDSHAKE )
+#endif
+    if( ( ret = ssl_fetch_input( ssl, 5 ) ) != 0 )
     {
         SSL_DEBUG_RET( 1, "ssl_fetch_input", ret );
         return( ret );
@@ -1249,18 +1262,22 @@
         return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
     }
 
-    if( ssl->renegotiation == SSL_INITIAL_HANDSHAKE &&
-        ( ret = ssl_fetch_input( ssl, 5 + n ) ) != 0 )
+#if defined(POLARSSL_SSL_RENEGOTIATION)
+    if( ssl->renegotiation == SSL_INITIAL_HANDSHAKE )
+#endif
+    if( ( ret = ssl_fetch_input( ssl, 5 + n ) ) != 0 )
     {
         SSL_DEBUG_RET( 1, "ssl_fetch_input", ret );
         return( ret );
     }
 
     buf = ssl->in_msg;
-    if( !ssl->renegotiation )
-        n = ssl->in_left - 5;
-    else
+#if defined(POLARSSL_SSL_RENEGOTIATION)
+    if( ssl->renegotiation != SSL_INITIAL_HANDSHAKE )
         n = ssl->in_msglen;
+    else
+#endif
+        n = ssl->in_left - 5;
 
     ssl->handshake->update_checksum( ssl, buf, n );
 
@@ -1423,6 +1440,7 @@
         if( p[0] == 0 && p[1] == SSL_EMPTY_RENEGOTIATION_INFO )
         {
             SSL_DEBUG_MSG( 3, ( "received TLS_EMPTY_RENEGOTIATION_INFO " ) );
+#if defined(POLARSSL_SSL_RENEGOTIATION)
             if( ssl->renegotiation == SSL_RENEGOTIATION )
             {
                 SSL_DEBUG_MSG( 1, ( "received RENEGOTIATION SCSV during renegotiation" ) );
@@ -1432,6 +1450,8 @@
 
                 return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
             }
+            renegotiation_info_seen = 1;
+#endif /* POLARSSL_SSL_RENEGOTIATION */
             ssl->secure_renegotiation = SSL_SECURE_RENEGOTIATION;
             break;
         }
@@ -1490,7 +1510,9 @@
 
         case TLS_EXT_RENEGOTIATION_INFO:
             SSL_DEBUG_MSG( 3, ( "found renegotiation extension" ) );
+#if defined(POLARSSL_SSL_RENEGOTIATION)
             renegotiation_info_seen = 1;
+#endif
 
             ret = ssl_parse_renegotiation_info( ssl, ext + 4, ext_size );
             if( ret != 0 )
@@ -1501,8 +1523,10 @@
     defined(POLARSSL_KEY_EXCHANGE__WITH_CERT__ENABLED)
         case TLS_EXT_SIG_ALG:
             SSL_DEBUG_MSG( 3, ( "found signature_algorithms extension" ) );
+#if defined(POLARSSL_SSL_RENEGOTIATION)
             if( ssl->renegotiation == SSL_RENEGOTIATION )
                 break;
+#endif
 
             ret = ssl_parse_signature_algorithms_ext( ssl, ext + 4, ext_size );
             if( ret != 0 )
@@ -1608,12 +1632,13 @@
     /*
      * Renegotiation security checks
      */
-    if( ssl->secure_renegotiation == SSL_LEGACY_RENEGOTIATION &&
+    if( ssl->secure_renegotiation != SSL_SECURE_RENEGOTIATION &&
         ssl->allow_legacy_renegotiation == SSL_LEGACY_BREAK_HANDSHAKE )
     {
         SSL_DEBUG_MSG( 1, ( "legacy renegotiation, breaking off handshake" ) );
         handshake_failure = 1;
     }
+#if defined(POLARSSL_SSL_RENEGOTIATION)
     else if( ssl->renegotiation == SSL_RENEGOTIATION &&
              ssl->secure_renegotiation == SSL_SECURE_RENEGOTIATION &&
              renegotiation_info_seen == 0 )
@@ -1635,6 +1660,7 @@
         SSL_DEBUG_MSG( 1, ( "renegotiation_info extension present (legacy)" ) );
         handshake_failure = 1;
     }
+#endif /* POLARSSL_SSL_RENEGOTIATION */
 
     if( handshake_failure == 1 )
     {
@@ -1831,16 +1857,29 @@
     *p++ = (unsigned char)( ( TLS_EXT_RENEGOTIATION_INFO >> 8 ) & 0xFF );
     *p++ = (unsigned char)( ( TLS_EXT_RENEGOTIATION_INFO      ) & 0xFF );
 
-    *p++ = 0x00;
-    *p++ = ( ssl->verify_data_len * 2 + 1 ) & 0xFF;
-    *p++ = ssl->verify_data_len * 2 & 0xFF;
+#if defined(POLARSSL_SSL_RENEGOTIATION)
+    if( ssl->renegotiation != SSL_INITIAL_HANDSHAKE )
+    {
+        *p++ = 0x00;
+        *p++ = ( ssl->verify_data_len * 2 + 1 ) & 0xFF;
+        *p++ = ssl->verify_data_len * 2 & 0xFF;
 
-    memcpy( p, ssl->peer_verify_data, ssl->verify_data_len );
-    p += ssl->verify_data_len;
-    memcpy( p, ssl->own_verify_data, ssl->verify_data_len );
-    p += ssl->verify_data_len;
+        memcpy( p, ssl->peer_verify_data, ssl->verify_data_len );
+        p += ssl->verify_data_len;
+        memcpy( p, ssl->own_verify_data, ssl->verify_data_len );
+        p += ssl->verify_data_len;
 
-    *olen = 5 + ssl->verify_data_len * 2;
+        *olen = 5 + ssl->verify_data_len * 2;
+    }
+    else
+#endif /* POLARSSL_SSL_RENEGOTIATION */
+    {
+        *p++ = 0x00;
+        *p++ = 0x01;
+        *p++ = 0x00;
+
+        *olen = 5;
+    }
 }
 
 #if defined(POLARSSL_SSL_MAX_FRAGMENT_LENGTH)
@@ -1999,7 +2038,9 @@
      * If not, try looking up session ID in our cache.
      */
     if( ssl->handshake->resume == 0 &&
+#if defined(POLARSSL_SSL_RENEGOTIATION)
         ssl->renegotiation == SSL_INITIAL_HANDSHAKE &&
+#endif
         ssl->session_negotiate->length != 0 &&
         ssl->f_get_cache != NULL &&
         ssl->f_get_cache( ssl->p_get_cache, ssl->session_negotiate ) == 0 )
diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index 7eec364..91ce32d 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -2797,7 +2797,7 @@
      * On client, make sure the server cert doesn't change during renego to
      * avoid "triple handshake" attack: https://secure-resumption.com/
      */
-#if defined(POLARSSL_SSL_CLI_C)
+#if defined(POLARSSL_SSL_RENEGOTIATION) && defined(POLARSSL_SSL_CLI_C)
     if( ssl->endpoint == SSL_IS_CLIENT &&
         ssl->renegotiation == SSL_RENEGOTIATION )
     {
@@ -2817,7 +2817,7 @@
             return( POLARSSL_ERR_SSL_BAD_HS_CERTIFICATE );
         }
     }
-#endif /* POLARSSL_SSL_CLI_C */
+#endif /* POLARSSL_SSL_RENEGOTIATION && POLARSSL_SSL_CLI_C */
 
     if( ssl->authmode != SSL_VERIFY_NONE )
     {
@@ -3260,11 +3260,13 @@
     polarssl_free( ssl->handshake );
     ssl->handshake = NULL;
 
+#if defined(POLARSSL_SSL_RENEGOTIATION)
     if( ssl->renegotiation == SSL_RENEGOTIATION )
     {
         ssl->renegotiation =  SSL_RENEGOTIATION_DONE;
         ssl->renego_records_seen = 0;
     }
+#endif
 
     /*
      * Switch in our now active transform context
@@ -3329,8 +3331,10 @@
     // TODO TLS/1.2 Hash length is determined by cipher suite (Page 63)
     hash_len = ( ssl->minor_ver == SSL_MINOR_VERSION_0 ) ? 36 : 12;
 
+#if defined(POLARSSL_SSL_RENEGOTIATION)
     ssl->verify_data_len = hash_len;
     memcpy( ssl->own_verify_data, ssl->out_msg + 4, hash_len );
+#endif
 
     ssl->out_msglen  = 4 + hash_len;
     ssl->out_msgtype = SSL_MSG_HANDSHAKE;
@@ -3454,8 +3458,10 @@
         return( POLARSSL_ERR_SSL_BAD_HS_FINISHED );
     }
 
+#if defined(POLARSSL_SSL_RENEGOTIATION)
     ssl->verify_data_len = hash_len;
     memcpy( ssl->peer_verify_data, buf, hash_len );
+#endif
 
     if( ssl->handshake->resume != 0 )
     {
@@ -3607,7 +3613,11 @@
 
     ssl_set_ciphersuites( ssl, ssl_list_ciphersuites() );
 
+#if defined(POLARSSL_SSL_RENEGOTIATION)
     ssl->renego_max_records = SSL_RENEGO_MAX_RECORDS_DEFAULT;
+    memset( ssl->renego_period, 0xFF, 7 );
+    ssl->renego_period[7] = 0x00;
+#endif
 
 #if defined(POLARSSL_DHM_C)
     if( ( ret = mpi_read_string( &ssl->dhm_P, 16,
@@ -3681,12 +3691,16 @@
     int ret;
 
     ssl->state = SSL_HELLO_REQUEST;
+
+#if defined(POLARSSL_SSL_RENEGOTIATION)
     ssl->renegotiation = SSL_INITIAL_HANDSHAKE;
-    ssl->secure_renegotiation = SSL_LEGACY_RENEGOTIATION;
+    ssl->renego_records_seen = 0;
 
     ssl->verify_data_len = 0;
-    memset( ssl->own_verify_data, 0, 36 );
-    memset( ssl->peer_verify_data, 0, 36 );
+    memset( ssl->own_verify_data, 0, SSL_VERIFY_DATA_MAX_LEN );
+    memset( ssl->peer_verify_data, 0, SSL_VERIFY_DATA_MAX_LEN );
+#endif
+    ssl->secure_renegotiation = SSL_LEGACY_RENEGOTIATION;
 
     ssl->in_offt = NULL;
 
@@ -3707,8 +3721,6 @@
     ssl->transform_in = NULL;
     ssl->transform_out = NULL;
 
-    ssl->renego_records_seen = 0;
-
     memset( ssl->out_ctr, 0, SSL_BUFFER_LEN );
     memset( ssl->in_ctr, 0, SSL_BUFFER_LEN );
 
@@ -4251,21 +4263,29 @@
 }
 #endif /* POLARSSL_SSL_TRUNCATED_HMAC */
 
-void ssl_set_renegotiation( ssl_context *ssl, int renegotiation )
-{
-    ssl->disable_renegotiation = renegotiation;
-}
-
 void ssl_legacy_renegotiation( ssl_context *ssl, int allow_legacy )
 {
     ssl->allow_legacy_renegotiation = allow_legacy;
 }
 
+#if defined(POLARSSL_SSL_RENEGOTIATION)
+void ssl_set_renegotiation( ssl_context *ssl, int renegotiation )
+{
+    ssl->disable_renegotiation = renegotiation;
+}
+
 void ssl_set_renegotiation_enforced( ssl_context *ssl, int max_records )
 {
     ssl->renego_max_records = max_records;
 }
 
+void ssl_set_renegotiation_period( ssl_context *ssl,
+                                   const unsigned char period[8] )
+{
+    memcpy( ssl->renego_period, period, 8 );
+}
+#endif /* POLARSSL_SSL_RENEGOTIATION */
+
 #if defined(POLARSSL_SSL_SESSION_TICKETS)
 int ssl_set_session_tickets( ssl_context *ssl, int use_tickets )
 {
@@ -4400,6 +4420,7 @@
     return( ret );
 }
 
+#if defined(POLARSSL_SSL_RENEGOTIATION)
 #if defined(POLARSSL_SSL_SRV_C)
 /*
  * Write HelloRequest to request renegotiation on server
@@ -4513,6 +4534,30 @@
 }
 
 /*
+ * Check record counters and renegotiate if they're above the limit.
+ */
+static int ssl_check_ctr_renegotiate( ssl_context *ssl )
+{
+    if( ssl->state != SSL_HANDSHAKE_OVER ||
+        ssl->renegotiation == SSL_RENEGOTIATION_PENDING ||
+        ssl->disable_renegotiation == SSL_RENEGOTIATION_DISABLED )
+    {
+        return( 0 );
+    }
+
+    // TODO: adapt for DTLS
+    if( memcmp( ssl->in_ctr,  ssl->renego_period, 8 ) <= 0 &&
+        memcmp( ssl->out_ctr, ssl->renego_period, 8 ) <= 0 )
+    {
+        return( 0 );
+    }
+
+    SSL_DEBUG_MSG( 0, ( "record counter limit reached: renegotiate" ) );
+    return( ssl_renegotiate( ssl ) );
+}
+#endif /* POLARSSL_SSL_RENEGOTIATION */
+
+/*
  * Receive application data decrypted from the SSL layer
  */
 int ssl_read( ssl_context *ssl, unsigned char *buf, size_t len )
@@ -4522,6 +4567,14 @@
 
     SSL_DEBUG_MSG( 2, ( "=> read" ) );
 
+#if defined(POLARSSL_SSL_RENEGOTIATION)
+    if( ( ret = ssl_check_ctr_renegotiate( ssl ) ) != 0 )
+    {
+        SSL_DEBUG_RET( 1, "ssl_check_ctr_renegotiate", ret );
+        return( ret );
+    }
+#endif
+
     if( ssl->state != SSL_HANDSHAKE_OVER )
     {
         ret = ssl_handshake( ssl );
@@ -4566,6 +4619,7 @@
             }
         }
 
+#if defined(POLARSSL_SSL_RENEGOTIATION)
         if( ssl->in_msgtype == SSL_MSG_HANDSHAKE )
         {
             SSL_DEBUG_MSG( 1, ( "received handshake message" ) );
@@ -4648,6 +4702,7 @@
                 return( POLARSSL_ERR_SSL_UNEXPECTED_MESSAGE );
             }
         }
+#endif /* POLARSSL_SSL_RENEGOTIATION */
 
         /* Fatal and closure alerts handled by ssl_read_record() */
         if( ssl->in_msgtype == SSL_MSG_ALERT )
@@ -4694,6 +4749,14 @@
 
     SSL_DEBUG_MSG( 2, ( "=> write" ) );
 
+#if defined(POLARSSL_SSL_RENEGOTIATION)
+    if( ( ret = ssl_check_ctr_renegotiate( ssl ) ) != 0 )
+    {
+        SSL_DEBUG_RET( 1, "ssl_check_ctr_renegotiate", ret );
+        return( ret );
+    }
+#endif
+
     if( ssl->state != SSL_HANDSHAKE_OVER )
     {
         if( ( ret = ssl_handshake( ssl ) ) != 0 )