Walter Soldierer’s Blog

Ab Firmware-Version xx.04.74 hat AVM die Login-Prozedur für die Fritzbox von einem normalen Passwort-Login zu einem recht komplizierten challenge-response Verfahren geändert. Ich lese mit einem Perl script die Telefonanrufe alle 6 Stunden aus und logge sie in eine Datei. Nach dem letzten Firmware-Update funktionierte das script plötzlich nicht mehr. Ich meide in Zukunft solche updates. Bereits zum zweiten mal musste ich nämlich nach einem update mehrere Stunden investieren, um die Änderungen zu verstehen und mein script entsprechend anzupassen. Hier also meine Perl Implementation des neuen Login-Verfahrens. (more…)

Wir hatten uns vor Monaten entschlossen, den alten 1&1 Vertrag auf DSL 6000 zu erhöhen, auch wenn man dafür auf dem platten Land mit 5 Euro mtl. Zusatzkosten bestraft wird. Jetzt habe ich endlich die Zeit gefunden, meine neue FRITZ!Box Fon WLAN 7270 zu installieren. DSL 6000 funktioniert noch nicht 100%. Anscheinend wird die Bandbreite auf 3456 kBit/s gedrosselt. Ich habe den 1&1 support gebeten, das zu korrigieren. Die FRITZ!Box hängt im Netzwerkschrank im Keller.  Tolles Gerät mit vielen features. Endlich haben wir den beiden großen Kindern auch ihre eigenen Rufnummern und DECT Telefone verpasst. Kein stundenlanges Blockieren der Leitung mehr. (more…)

Whenever I take a look at our web server log files, I am amazed how many robots are trying to hack their way into our machines every day. And whenever I help a friend or neighbor to fix a computer problem, I need to explain even the most essential safety measures as most PCs are infected with some trojan or virus already. Computer and network security is a big issue, don’t underestimate the risks. I first noticed this years ago when I installed a free personal firewall on my PC. Only seconds after the program started to do its job, it alerted me of suspicious activity on ports and protocols that I even didn’t know existed. Steve Gibson calls this activity Internet Background Radiation. Much of this is not merely junk but malicious traffic. To protect my personal computers, data, and privacy, I have taken a number of simple security measures which I want to share with you. (more…)

When I heard Steve Gibson talk about the Ironkey I wanted to have one. Its basically a USB storage device with strong hardware encryption built in. In a earlier post about encryption I said

“Some USB drives (SanDisk, Lexar, Kingston, IronKey) have hardware encryption built in, but when it comes to encryption, I prefer to stay away from proprietary implementations.”

Well, the Ironkey is proprietary of course. However, after Steve’s interview with Ironkey’s CEO I was very curious how the thing would actually work. For my daily needs Ironkey’s level of security is more than I need anyway. And I’m not a big fan of conspiracy theories. Ironkey is very likely not a subsidiary of the NSA. And should I ever be concerned about some government agency breaking into it, I can still encrypt the data on my Ironkey with PGP. Call me paranoid but actually I run a copy on the Ironkey and use it to encrypt the hundreds of entries in my master passwords file.

Gnu Privacy Guard (GPG) is an open source PGP clone. It uses strong encryption to protect emails as well as files and folders. For encrypting drives, folders, and files I use a different piece of software (Truecrypt). GPG is my encryption tool for email. The majority of email traffic on the Internet still goes unencrypted, which still amazes me. Many email users don’t know that their email can be easily intercepted and read. PGP’s documentation compares sending email to sending paper postcards, and rightly so. There is no envelope. Any person having access to a mail server or a router could read or automatically filter the many emails that are processed every day. Wireless connections are even more of a problem. There is software which can make email data visible if it is sent over an unencrypted WLAN connection.

So do I encrypt all my email? No. I wish I could, but none of my friends and colleagues uses email encryption. There is only two things I can do: Download my mail with a secure protocol to at least encrypt the last hop, and never forget that emails are like paper postcards that not only the postman can read.

Free encryption software (1): Introduction
Free encryption software (2): File encryption on USB flash drives
Free encryption software (3): Hard disc encryption

I have been doing do a lot of email marketing lately. Our email marketing service does a pretty good job at removing records with an invalid email address from the imported data set. However, some invalid addresses still slip through and cause unnecessary bounces and license costs. We therefore need to correct or remove all invalid addresses before we import them. Some can be easily corrected without involving the subscriber, like

someone@hotmail
someone @ yahoo.com
someone@gmail.cmo

Others can be removed from the subscriber list because they originate from fake subscriptions, like test@justtesting.

I was looking for an online tool to clean up an email address list but could only find tools that process one address at a time. So I read RFC 3696 to learn more about valid email address formats and wrote my own. The tool does email format checks for most of the RFC requirements. It also queries the email domain’s DNS server to look for MX and A records.

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