Plaintext logins with Dovecot and Ubuntu


Disallow plaintext authentication in non-SSL mode?

Webmin permits you to enable non-SSL connections on its Dovecot SSL Configuration page, but on Ubuntu at least, that edits /etc/dovecot/dovecot.conf by changing 'yes' here to 'no':

disable_plaintext_auth = no

but the same thing also has to be done in /etc/dovecot/dovecot-postfix.conf ... manually for now.

Debugging web pages using MySQL


mysql> <span style="text-decoration: underline;">show variables like '%log%';
| Variable_name                       | Value                           |
| back_log                            | 50                              |
| general_log                         | OFF                             |
| general_log_file                    | /var/run/mysqld/mysqld.log      |
| log                                 | OFF                             |
| log_bin                             | OFF                             |
| log_error                           | /var/log/mysqld.log             |
| log_output                          | FILE                            |
| slow_query_log                      | OFF                             |
| slow_query_log_file                 | /var/run/mysqld/mysqld-slow.log |
| sql_log_bin                         | ON                              |
| sql_log_off                         | OFF                             |
| sql_log_update                      | ON                              |
| sync_binlog                         | 0                               |
40 rows in set (0.00 sec)

mysql> <span style="text-decoration: underline;">SET GLOBAL general_log = 'ON';</span>
$ <span style="text-decoration: underline;">sudo less /var/run/mysqld/mysqld.log</span>
... (log entries scroll) ...
$ <span style="text-decoration: underline;">fg</span>
mysql> <span style="text-decoration: underline;">SET GLOBAL general_log = 'OFF';</span>
mysql> QUIT;

Adding PayJunction to OSCommerce


Applies to: PayJunction payment plugin for OSCommerce, when OSC has the CVV accepting patch installed.


Bug in the payjunction.php file -- Line 122 (approximately) reads:

$result = $cc_validation->validate($HTTP_POST_VARS['payjunction_cc_number'],
], $HTTP_POST_VARS['payjunction_cc_expires_year']);

and should read:

$result = $cc_validation->validate($HTTP_POST_VARS['payjunction_cc_number'],
], $HTTP_POST_VARS['payjunction_cc_expires_year'], 

Also, approximately line 136, below the "case -4 ... TEXT_CCVAL_ERROR_INVALID_DATE" should be a stanza:

case -5:

Which is what was happening above (the CVV was not being passed) -- and then the -5 error (invalid CVV) is not handled either.

Die Shapes and Radially Staggered Bonding


Over ten years ago I put aside my copy of the HP Journal, December 1996 edition for later reading. I would like to relate some thoughts I have recently had on an article in it.

As pin counts of integrated circuits have continued to rise, the difficulties in arranging wire bonds -- which connect the "pads" on the chip (die) to the landing zones on the "pins" that connect through the "device" (plastic or ceramic) to the outside world -- have likewise continued to rise. As the connections get closer, simply putting pads around the edge of the die makes them too close, and too small, to accurately bond with a flying piece of semi-molten gold wire.

The article shows micrographs of HP's technique for radially staggered bonding. This does increase the available size and separation of the pads but it really only defers the problem. Another problem with device yield is that the "street" which is traditionally cut by a saw requires a significant amount of area.

For a better overall solution, consider the bee's honeycomb.

A honeycomb is a matrix of hexagons. Not only is every cell nearly the same, but the amount of material used to construct the honeycomb is minimized.

If a silicon wafer were cut into hexagons, perhaps by a laser, that would reduce the amount of area lost. Further, because a hexagon more closely approximates a circle -- which is the end convergence of the radially staggered bonding process. (The clue is, "radial" -- think ... circle!)

This whole process could significantly increase both yield and pin count.

PostgreSQL connections


If you are using an application that needs PostgreSQL connections

on your LAN, don't forget to add, or replace, in file postgresql.conf

listen_addresses ='*'

Otherwise, postgres will bind only to 'localhost' and won't be accessible from your network. You will just get Connection Refused errors until you add this parameter to enable listening to TCP sockets. (That's port 5432 if you look in /etc/services.)

NOTE: Webmin doesn't give you a way to edit the parameters in postgresql.conf, you'll have to do it manually.