Category Archives: iPhone/iPad

A Little Printing Please – Packet Capture

Uh, I wasn’t aware of so many different printing protocols. Do you? While I was trying to solve a little printing problem I took a packet capture of three different printing variants over TCP/IP: Raw via TCP port 9100, LPD/LPR via TCP port 515, and Apple’s AirPrint which uses the Internet Printing Protocol IPP. As always, you can download this pcap and have a look at it by yourself.

Continue reading A Little Printing Please – Packet Capture

Yamaha R-N500 Network Receiver Packet Capture

Last but not least I was interested which “home-calling” connections my Yamaha R-N500 Network Receiver initiates. In my previous post I already analyzed the open ports within the network, while I showed a complete Apple AirPlay capture here. This time I was only interested in outgoing TCP/UDP connections to the Internet as well as how the Yamaha App “NP Controller” communicates with the receiver.

It turned out that it was not easy for me to fully analyze such a packet trace even though only a couple of connections were made. It consists of many protocols that I am not familiar with such as UPnP, MDNS, SSDP, and RTP. Anyway, ere we go:

Continue reading Yamaha R-N500 Network Receiver Packet Capture

Apple AirPlay Capture

I was interested in how Apple AirPlay works in my network. I am using an iPad to stream music to a Yamaha R-N500 network receiver. There is a great Unofficial AirPlay Protocol Specification which already shows many details about the used protocols. But since I am a networking guy I captured the whole process in order to analyze it with Wireshark.

Following is a downloadable pcap if you want to have a look at it by yourself as well as some Wireshark and NetworkMiner screenshots for a first glance.

Continue reading Apple AirPlay Capture

Threema: Zwei Hinweise

Nach wie vor empfehle ich Threema, wenn es um einen sicheren, also Ende-zu-Ende verschlüsselten, Austausch von Nachrichten, Fotos, usw. geht.

Threema hat allerdings zwei Besonderheiten, die andere Chat Programme nicht haben: Eine Art Punktesystem als Wertung der Authentizität des Gesprächspartners, und die Notwendigkeit, ein Backup seiner ID zu machen, wenn man das Handy einmal wechseln möchte. Beide Sachen haben ihren Ursprung in der Kryptographie und sind daher nicht gerade einleuchtend für den Otto Normalverbraucher. Daher hier ein paar Worte dazu:

Continue reading Threema: Zwei Hinweise

Palo Alto Remote Access VPN for iPhone

I tested the Palo Alto GlobalProtect app on my iPhone, but also the native IPsec Cisco VPN-Client on iOS which connects to the GlobalProtect Gateway on a Palo Alto firewall, too. Since this variant needs no further licenses from Palo Alto, it is a cheap alternative for a basic VPN connection.

Though not that much exciting, there are a few differences in the logs on the firewall which I will show here on the basis of a few screenshots.

Continue reading Palo Alto Remote Access VPN for iPhone

E-Mail Übertragung verschlüsseln

Zur Zeit wird viel über Abhörmaßnahmen im Internet und speziell über das generelle Mitschneiden von Traffic normaler User geredet. Und während große Firmen gezielt Verschlüsselungstechniken einsetzen können hat der Otto Normalverbraucher kaum das Wissen, um ernsthaft etwas gegen das Mitschneiden seiner Daten zu tun. Dabei ist es gar nicht so schwer, zumindest die Übertragung der eigenen E-Mails hin zu seinem Provider über entsprechende Maßnahmen abzusichern. Ob man damit die internationalen Geheimdienste aussperrt bleibt fraglich, aber zumindest schränkt man das Mitlesen der privaten E-Mails durch Unbefugte im Internet deutlich ein! Hier kommt also eine Erklärung inkl. einiger Screenshots der gängigen E-Mail Programme und Smartphones, um die eigenen E-Mails über einen verschlüsselten Kanal zu übertragen. Continue reading E-Mail Übertragung verschlüsseln