bugtraq - Re: base64

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date: Tue, 23 Sep 2003 20:10:36 +0200
From: "Lothar Kimmeringer" <bugtraq@...meringer.de>
To: "BugTraq@...urityfocus.com" <BugTraq@...urityfocus.com>
Subject: Re: base64


On Tue, 23 Sep 2003 12:18:31 -0400 (EDT), Birl wrote:

>Excuse my ignorance.  I tried to pook around some B64 attachements in my
>email files for an answer.
>
>
>Are you stating that an =
>
>1) should not appear in B64 at all
>2) should not appear in the middle of a line, but only at the EOLN
>3) should only appear at the end of a B64 file

See the corresponding RFC. The number of characters in a base64-coded
text must be a multiply of 4. So ='s are used if there aren't enough
characters and are added at the end of the text.

= is not a valid character inside Base64 and an encoder should stop
with an error or stops decoding.

>Answering that question could help me better determine how to write a
>procmail filter for this.

/.*=[^=]/
(untested)


Regards, Lothar

-- 
Lothar Kimmeringer                E-Mail: mailbody@...meringer.de
               PGP-encrypted mails preferred (Key-ID: 0x8BC3CD81)

Always remember: The answer is forty-two, there can only be wrong
                 questions!