+
+ bulk = conf['bulk']
+
+ if bulk == 'v0':
+ blksz = C.gcciphers[conf['cipher']].blksz
+ mtu -= mac_tagsz() # MAC tag
+ mtu -= 4 # Sequence number
+ mtu -= blksz # Initialization vector
+
+ elif bulk == 'iiv':
+ mtu -= mac_tagsz() # MAC tag
+ mtu -= 4 # Sequence number
+
+ elif bulk == 'naclbox':
+ mtu -= 16 # MAC tag
+ mtu -= 4 # Sequence number
+
+ else:
+ die("Unknown bulk transform `%s'" % bulk)