Friday, October 14, 2011

combining greylisting with spam scores - working exim example

...personal experience with greylisting, some inspiration (some i can't remember anymore...), and some thoughts led to the following (implemented) idea:

let's suppose you trust the system's spam score to the extent that
- a low enough spam score is fairly-certainly correct

why not use a low enough threshold to have first-time senders pass by?
[/etc/exim4/conf.d/acl/40_exim4-config_check_data.rul]

>defer
>  ...
>  log_message = message deferred: probable spam and greylistd 
>  message     = Message temporarily deferred
>  condition   = ${if and \
>                  {\
>                    { >{$spam_score_int}{75}}\
>                    {eq{grey}\
>                      {${readsocket{/var/run/greylistd/socket}\
>                                      {${mask:$sender_host_address/24} \
>                                         $sender_address \
>                                         $local_part@$domain}\
>                                        {5s}{}{}}\
>                      }\
>                    }\
>                  }\
>                }
>  delay       = 4m

Sunday, March 6, 2011

personal reminder: ratpoison and an empty, gray java GUI

"How to un-break graphical Java apps under Ratpoison" suggests wmname to make the JVM believe it runs on a different window manager:
$ wmname LG3D
implies the JVM ran on lg3d (Project Looking Glass - a desktop utilizing 3D aspects in the UI), a non-re-parenting window manager written by Sun; this one is on java's hard-coded list of known non-reparenting window managers.

note for OpenJDK: according to this post "versions of OpenJDK that ship with some operating system distributions—at least Debian (and Ubuntu) and Arch Linux in March and August of 2009, respectively—have had this problem fixed by the vendors."

Friday, March 4, 2011

Manually add account to Google Authenticator - Enter key in Base32 Encoding

wanted to use OpenID with Multi-factor authentication as a Single Sign-On (SSO) for online services; in particular, i wanted to combine a regular password with a One-Time Password namely, a TOTP token.

Google Authenticator supports TOTP, and not only for their own 2-step verification but one can "Manually add" other accounts.

The bridging part from TOTP to OpenID, in my case, comes from Clavid (cf. OTP@Clavid).

Now to the tiny bit of information that might save you quite some minutes: when entering your secret key into these two locations to set-up an account

  • Google Authenticator expects the string to be RFC4648 Base32 encoded
  • Clavid expects the string to be hex encoded

Tuesday, January 4, 2011

personal reminder: rfkill to toggle bluetooth

toggling bluetooth (on a Lenovo ThinkPad X200s / Ubuntu 10.x) via rfkill:
rfkill list
rfkill block 0
rfkill unblock 0