added max_record_size extension

1 files changed, 149 insertions, 0 deletions

diff --git a/lib/ext_max_record.c b/lib/ext_max_record.c
new file mode 100644
index 0000000000..09f269df5d
--- /dev/null
+++ b/lib/ext_max_record.c
@@ -0,0 +1,149 @@
+/*
+ *      Copyright (C) 2001 Nikos Mavroyanopoulos
+ *
+ * This file is part of GNUTLS.
+ *
+ * GNUTLS is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * GNUTLS is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
+ */
+
+#include "gnutls_int.h"
+#include "gnutls_errors.h"
+#include "gnutls_num.h"
+#include "ext_max_record.h"
+
+/* 
+ * In case of a server: if a MAX_RECORD_SIZE extension type is received then it stores
+ * into the state the new value. The server may use gnutls_get_max_record_size(),
+ * in order to access it.
+ *
+ * In case of a client: If a different max record size (than the default) has
+ * been specified then it sends the extension.
+ *
+ */
+
+int _gnutls_max_record_recv_params( GNUTLS_STATE state, const opaque* data, int data_size) {
+	size_t new_size;
+	
+	if (state->security_parameters.entity == GNUTLS_SERVER) {
+		if (data_size > 0) {
+			
+			if ( data_size != 1) {
+				gnutls_assert();
+				return GNUTLS_E_UNEXPECTED_PACKET_LENGTH;
+			}
+			
+			new_size = _gnutls_mre_num2record(data[0]);
+
+			if (new_size < 0) {
+				gnutls_assert();
+				return new_size;
+			}
+
+			state->security_parameters.max_record_size = new_size;
+		}
+	} else { /* CLIENT SIDE - we must check if the sent record size is the right one 
+	          */
+		if (data_size > 0) {
+
+			if ( data_size != 1) {
+				gnutls_assert();
+				return GNUTLS_E_UNEXPECTED_PACKET_LENGTH;
+			}
+			
+			new_size = _gnutls_mre_num2record(data[0]);
+
+fprintf(stderr, "RECEIVING IT %d\n", new_size);
+
+			if (new_size < 0 || new_size != state->security_parameters.max_record_size) {
+				gnutls_assert();
+				return GNUTLS_E_ILLEGAL_PARAMETER;
+			}
+
+		}
+	
+	
+	}
+	
+	return 0;
+}
+
+/* returns data_size or a negative number on failure
+ * data is allocated localy
+ */
+int _gnutls_max_record_send_params( GNUTLS_STATE state, opaque** data) {
+	uint16 len;
+	/* this function sends the client extension data (dnsname) */
+	if (state->security_parameters.entity == GNUTLS_CLIENT) {
+
+		if (state->security_parameters.max_record_size != DEFAULT_MAX_RECORD_SIZE) {
+			len = 1;
+			(*data) = gnutls_malloc(len); /* hold the size and the type also */
+			if (*data==NULL) return GNUTLS_E_MEMORY_ERROR;
+			
+			(*data)[0] = _gnutls_mre_record2num( state->security_parameters.max_record_size);
+			return len;
+		}
+
+	} else { /* server side */
+
+		if (state->security_parameters.max_record_size != DEFAULT_MAX_RECORD_SIZE) {
+			len = 1;
+			(*data) = gnutls_malloc(len+2); /* hold the size and the type also */
+			if (*data==NULL) return GNUTLS_E_MEMORY_ERROR;
+			
+			(*data)[0] = _gnutls_mre_record2num( state->security_parameters.max_record_size);
+			return len;
+		}	
+	
+	
+	}
+
+	*data = NULL;
+	return 0;
+}
+
+/* Maps record size to numbers according to the
+ * extensions draft.
+ */
+int _gnutls_mre_num2record( int num) {
+	switch( num) {
+	case 1:
+		return 512;
+	case 2:
+		return 1024;
+	case 3:
+		return 2048;
+	case 4:
+		return 4096;
+	default:
+		return GNUTLS_E_ILLEGAL_PARAMETER;
+	}
+}
+
+int _gnutls_mre_record2num( int record_size) {
+	switch(record_size) {
+	case 512:
+		return 1;
+	case 1024:
+		return 2;
+	case 2048:
+		return 3;
+	case 4096:
+		return 4;
+	default:
+		return GNUTLS_E_ILLEGAL_PARAMETER;
+	}
+
+}