[dcc2] Files Draft

[codemastr]

I've been looking over the draft a bit more, and there was one thing that I
don't quite know about. Are the headers required to be in a specific order?
All the examples go id,name,size. Is that required? No where does it say it
is, but it also doesn't say that it isn't. Also, regardless of their order,
do the required fields have to go before any optional fields?

Also, about the sha1 header. I was thinking, should we use a header called
sha1? It seems to me a better, more expandable way is to use, "file-hash:"
or something similar.

So instead of:
sha1: blahblahblah

You have:
file-hash: sha1 blahblahblah

That makes it so you don't need to create a new header type each time you
want to use a different hashing function. For example, RIPEMD-160 is
generally regarded as being stronger than SHA1. So if I want, I should be
able to choose RIPEMD-160. Then, of course, you run into problems with "what
if the receiver doesn't support RIPEMD-160?" Well then you can specify
multiple headers!

file-hash: ripemd160 123456abc
file-hash: sha1 432165cba

You could even design it so you can specify more than one in a single
header.

Again, the reason for this is, it is, in my mind, a bad idea to lock
yourself into a particular algorithm. One day, 30 years from now, sha1 might
be cracked and therefore useless. So there should be a method that allows
people to easily switch to a different algorithm.

-- codemastr