688898de   
   XPost: comp.unix.programmer, comp.programming   
   From: philip+usenet@paeps.cx   
      
   Ramon F Herrera  wrote:   
   > On Sep 11, 1:25 pm, "Tom Einertson"  wrote:   
   >> "Ramon F Herrera"  wrote in messagenews:26   
   0b840-9d5d-4f7b-9683-45d96a82ece2@o9g2000yqj.googlegroups.com...   
   >>   
   >> > In my preliminary client & server versions, I will send the data in   
   >> > clear text, but a future version will be based on SSL.   
   >>   
   >> > Given that future direction (SSL on Version 2), should I base my   
   >> > Version 1 on:   
   >>   
   >> > (1) UDP   
   >> > (2) TCP   
   >> > (3) Irrelevant   
   >>   
   >> If you plan to convert to SSL eventually, then I would use TCP for Version   
   >> 1.  Although there are   
   >> differences between TCP and SSL (SSL is more complicated) both of these   
   >> protocols provide the   
   >> same type of service (stream).   UDP provides a datagram service, so you   
   >> have to deal with a   
   >> different set of issues.   
   >   
   > Thanks, Tom. You confirmed my suspicions. I have always wondered why:   
   >   
   >  - IP  has an encrypted equivalent: IPsec   
   >  - TCP has an encrypted equivalent: SSL   
   >   
   > but there is no such thing as an encrypted UDP.   
      
   I'm a bit dubious about the word "equivalent" here.  That would imply that   
   they are "alternatives", which they are not.  SSL merely encapsulates the   
   payload of TCP segments and IPsec either encapsulates the payload of IP   
   packets or entire IP packets in new IP packets.   
      
   It is perfectly possible to encrypt UDP using IPsec in transport mode and   
   obviously in tunnel mode.  Likewise for TCP.  You can even have SSL in TCP in   
   IPsec in IP if you like.   
      
   There is also nothing to stop you from running TLS on top of UDP.  Or on top   
   of anything else, for that matter.  A while back, when I was implementing IEEE   
   802.1X for a project, I ran TLS over EAP over Ethernet.  No TCP anywhere near.   
      
   Much as you don't like to hear this advice, you would find Stevens volume 1   
   very helpful in understanding the layering of protocols.  Once you understand   
   how the protocols work, implementing network programs is not all that   
   difficult, regardless of what programming language or API you choose.   
      
    - Philip   
      
   --   
   Philip Paeps                                    Please don't email any replies   
   philip@paeps.cx                                     I follow the newsgroup.   
      
     Real programmers don't announce how many times the   
     operations department called them last night.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)