punycode licensing

[Matt Caswell]

PR 9199 incorporates the C punycode implementation from RFC3492:

https://github.com/openssl/openssl/pull/9199

The RFC itself has this section in it:

B. Disclaimer and license

   Regarding this entire document or any portion of it (including the
   pseudocode and C code), the author makes no guarantees and is not
   responsible for any damage resulting from its use.  The author grants
   irrevocable permission to anyone to use, modify, and distribute it in
   any way that does not diminish the rights of anyone else to use,
   modify, and distribute it, provided that redistributed derivative
   works do not contain misleading author or version information.
   Derivative works need not be licensed under similar terms.

Which is quite confusing because on the one hand it places a requirement on
redistributed derivative works:

"provided that redistributed derivative works do not contain misleading author
or version information"

and then on the other hand states that derivative works are free to licence
under different terms:

"Derivative works need not be licensed under similar terms"

It seems to me that the above gives us the ability to just relicense this under
Apache 2 and incorporate it. But I'm not entirely sure.

Thoughts?

Matt