Re: Question on TLS wire format

[Tim Dierks <timd@xxxxxxxxxxxxx>]

At 1:20 PM -0600 7/16/97, Baber Amin wrote:
>According to TLS it is not backwards compatible with SSL v3, and the system
>will have to roll back to the SSL v3 protocol if the other side does not
>support TLS.  What and why is it different.  Since, I don't normally follow
>this list a detailed reply or a pointer to differences between TLS and SSL
>v3 will be greatly appreciated.
>
>I know that the TLS standard is not ratified yet, but is there a example
>implementation of it anywhere that I can look at.

For the most detail, you'll find that the TLS spec has been handily
equipped with two sets of change bars: ']' marks changes from revision 0 of
the draft (which was bit-for-bit compatible with SSL) and '|' marks changes
from the previous revision.

Here's a quick summary of the significant wire changes:
	- New algorithms for MACing, key derivation and finished messages
	- Variable-length block padding
	- More alert codes for more detailed error reporting
	- Different semantics for Certificate messages

The TLS effort has not been primarily about drastically improving SSL 3.0;
it's been about getting the protocol into the IETF standards process.

 - Tim

Tim Dierks - timd@xxxxxxxxxxxxx - www.consensus.com
     Software Haruspex - Consensus Development
  Developer of SSL Plus: SSL 3.0 Integration Suite