[hashcash] Re: regex bug or feature?

  • From: "Eric S. Johansson" <esj@xxxxxxxxxx>
  • To: hashcash@xxxxxxxxxxxxx
  • Date: Mon, 30 Nov 2015 09:04:03 -0500

no, there is nothing for tbird (or any other email client. I think
using regex here is not a good idea as it is easy to get it wrong. use
a "real" parser.

fwiw, I figured out a way to use hashcash as part of the smtp protocol.
since a hashcash stamp has the email address in plaintext, you can use
it in the rcpt part of the protocol. the error code can can be used to
indicate postage pricing changes. It could be implemented as an smtp
extension (ehlo).

advantages: minimal impact on smtp protocol, backwards compatible,
dynamic pricing/reputation, per address and domain pricing values. can
be implemented in a proxy

disadvantages: changes to the smtp protocol and other things that I'm
probably blind to :-) someday I'll get around to implementing this.

--- eric


On 11/30/2015 03:51 AM, Erich Eckner wrote:

Hi,

firts of all: I really like the idea and simplicity [1] of hashcash -
It's a pity that it's not widely used.

I have a question/suggestion regarding using regex for checking (-E):
It seems like the regex is directly encapsulated in ^ and $. This makes
the use of | somewhat strange:
hashcash -cEr "mailOne@serverOne|mailTwo@serverTwo"
will also match "mailOne@serverOnethousand" and "anymailTwo@serverTwo".
Is this intended? I would find it more intuitive if the regex was
encapsulated in "^(" and ")$" rather than "^" and "$". Would this have
any disadvantages?

cheers,
Erich

[1] Unfortunately I can only find an extension (=pennyPost) for
thunderbird which uses java (and is broken for my installation) - is
there any alternative or some patch for thunderbird?


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