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Re: BASE64 encoding of SRS hash may not work with some mail servers

2004-05-05 15:58:53
On Wed, 5 May 2004, Roger Moser wrote:

The mail server of ifw-dresden.de does not accept '/' in the envelope sender
(see sample below). But SRS uses base64 to encode the hash and therefore
there is a chance of 6.25% that there will be a slash in the envelope
sender.

A good workaround for this would be to use modified base64 as specified in
RFC 3548 (using - and _ instead of + and /). The IMAP version of modified
base64 (using , instead of /) is not suitable because , must be quoted in
email addresses.

Futher, many mail servers (e.g. yahoo.com) convert the envelope sender to
lower case when bouncing a mail.

How crap.

An alternative encoding would be base41 (just invented by me) to encode 2
bytes into 3 characters using following characters:
abcdefghijklmnopqrstuvwxyz0123456789_+-*=

I like that idea.

Less efficient but more standard would be to use base32 from RFC 3548.

-- 
Tony Finch  <dot(_at_)dotat(_dot_)at>  http://dotat.at/