Importing Burp CA into rooted Android device

The Android operating system is on the rise. The last months I spent a lot of time testing mobile devices, especially the Android platform.l

One of the things that helped me a lot, is the ability to intercept SSL traffic on my Wireless Access Point. Therefore I set up a laptop with Burp, airbase and some iptables commands to redirect the traffic to the Burp proxy. In the Android browser I could simply accept the certificate warning, but for applications like the Google Android Market that’s not possible. Therefore I had to import the Burp CA into my Android device. As far as I know, this is only possible for rooted (and s-off) phones! The follwing things are necessary:

– The PortSwiggerCA from your Burp install (see instructions here)
– The cacerts.bks (from your phone or from the Android source)
Bouncycastle Java Library

Except for the PortSwiggerCA, everything is included in this zip file. After adding the PortSwiggerCA, just execute the import-ca-and-upload.sh script and follow the instructions.

Happy intercepting!

Edit: Depending on which Android version you are running, Android now supports installing “Trusted Credentials”. It’s pretty simple: Download the Burp CA certificate (e.g. through the webinterface on http://burp/ or see below), rename cacert.der to cacert.crt, transfer it to your SD card (or /sdcard folder if you don’t have a physical card in your phone). Then go to “Settings – Security – Install from storage” and it should get recognised automatically. From now on you’ll get a very annoying message everytime you startup your phone (“Network may be monitored-by an unknown third party”) as if a custom CA is a bigger problem than the default CAs… To me all the default CAs are way worse “unknown third party”s. However, this setup is usually not working with your default Android browser and you might still need the steps above. Some apps work, but for example from Android 4.4 on Google uses certificate pinning on its Google server connections. Certificate pinning means you really have to apply hooking techniques to the app you are analysing.

3 thoughts on “Importing Burp CA into rooted Android device

  1. It’s weird: I overwrote the cacerts.bks with the modified one, but upon reboot it gets overwritten again. Also, the cp command doesn’t exist unless busybox is installed.
    So this doesn’t work for me. What version of android are you using (I tried several via the android SDK)

  2. You’re right about the cp command. Simply use “dd if=/from/file of=/to/file” instead. I’m using an HTC Desire on 2.2.0. Just some days after my post, the guys at intrepidusgroup did a similar post. Maybe it’s because you are using an emulated device instead of a real device. Check out that link for how you can do it for emulators.

  3. Pingback: Install Burp CA | Godick

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