ntor3, rend3: clarify extension field defaults.

These patch changes describe new default behaviors for extension
field lists, as appear in ntor3 and in many places throughout the
ntor3 protocol.  In general:

* Unrecognized extensions MUST be ignored.

Additionally, all the following rules apply _unless otherwise stated
in the documentation for an extension.

* Extensions are sent in sorted order.
* Extensions should only be sent once in a message
* If you receive multiple copies of an extension, only the first
  one counts.

This comes out of discussions on tor!525.

0 files changed, 0 insertions, 0 deletions