[hashcash] more format stuff
- From: Adam Back <adam@xxxxxxxxxxxxxxx>
- To: hashcash@xxxxxxxxxxxxx
- Date: Wed, 24 Mar 2004 17:48:16 +0000
OK reading http://www.blooberry.com/indexdot/html/topics/urlencoding.htm
one of the issues url-encoding is trying to deal with is shell's getting
confused with shell special chars encoded in urls.
So it is going to be simpler and safer for hashcash integration that
just shell's the hashcash executable if it can be sure there should be
no shell special characters. (So it can simply remove them).
If we define that people doing this should put '' around the args to
avoid shell interpretation, that leaves the shell unsafe char of '
(single quote).
And these would be disallowed for regexp parsability:
:;,=
and the non-printables > ascii(127) and whitespace would be banned for
7-bit cleanness and mail-transport survivability.
Apart from that we could leave encoding choice up to the extension.
URL encoding might be appropriate for some extension involving web
related stuff; some other encoding might be appropriate in some other
scenario.
As SpamAssassin 2.7 (which I think follows the linx kernel convention
that the odd number releases are beta / dev releases) is using the
existing version 0 format, I think it may be nicer to rev the version
number.
This brings us to current format:
version:date:resource:random
where version=0, for simplicity as no-one is using it retro-active
definition change that resource can not contain a :
New format:
version:date:resource:[extension]:random:counter
where extension is optional, version=1. no fields are allowed to contain
: or ' or whitespace or non-printable.
The extension format is something like:
name1=val1,val2;name2=val3
etc name, value pairs with values being , (comma) separated list ;
(semi-colon) name-value pairs separated by ; (semi-colons).
we could put some time limit on acceptance of the version 0 format so it
doesn't live for ever.
Adam
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