Traffic sniffing

Summary #

The toniebox communicates over https with its servers. It uses its Certificate Authority certifcate (flash:/cert/ca.der) to verify the tls connection. The box authenticates itself with a client certificate (flash:/cert/client.der) + private rsa key (flash:/cert/private.der). The communication is based on https and protobuf.

Known domains #


Attention! #

Your certificate may be banned if you send to many wrong requests to the Boxine servers.

Using mitmproxy #

The Toniebox can be man-in-the-middled by replacing the CA of the box with one you can control. You need to use mitmproxy v8.0.0 and use the mitmproxy-validity addon. You should prepare a system for transparent proxing with mitmproxy. The easiest way in my opinion to use an VM and set up the DHCP for the WiFi the way that the Toniebox gets the VM as gateway.

Don’t use the latest mitmproxy #

Don’t use mitmproxy v9 as it doesn’t support the needed sha-1 signature algoritms! Stick to 8.0.0 until further notice!

(OpenSSL Error([('SSL routines', '', 'no shared signature algorithms')]))

Create CA #

mitmproxy creates its CA on first run (/root/.mitmproxy/). I suggest to start it with the tool faketime or change your systems date to 2015-11-04. (It may work without, but no warranty) Don’t forget to run it as root.

Conversion to DER-format #

Afterwards you need convert the mitmproxy-ca-cert.cer into the DER-format

openssl x509 -inform PEM -outform DER -in mitmproxy-ca-cert.cer -out mitmproxy-ca-cert.der

Backup original files #

Afterwards you’ll need to backup the Toniebox’ CA and its client.der/private.der

cc3200tool read_file /cert/ca.der ca.der read_file /cert/client.der client.der read_file /cert/private.der private.der

Upload mitmproxy CA to the Toniebox #

cc3200tool write_file mitmproxy-ca-cert.der /cert/ca.der 

Convert client certificate to PEM-format #

openssl x509 -inform DER -outform PEM -in client.der -out client.cer
openssl rsa -inform DER -outform PEM -in private.der -out private.key
cat client.cer private.key > client.pem

Dump SSL-keys #

I suggest you to set the SSLKEYLOGFILE enviroment variable so you can record your traffic with Wireshark and decrypt it afterwards (Edit-Preferences-Protocols-TLS-(Pre)-Master-Secret log filename)

export SSLKEYLOGFILE=/root/keylogfile.txt

Run mitmproxy / mitmweb / mitmdump #

You can use mitmproxy, mitmweb or mitmdump. I prefered mitmweb

./mitmweb --verbose --web-host 0.0.0. --mode transparent --set client_certs=/root/client.pem --ssl-insecure -s /root/

Using wireshark over ssh #

You’ll need to install tcpdump on you target system. I also disabled password auth for sudoing tcpdump.

$ nano /etc/sudoers.d/tcpdump

%pcap ALL=NOPASSWD: /usr/bin/tcpdump

Attach pcap-group to tcpdump

sudo chgrp pcap /usr/bin/tcpdump
sudo chmod 750 /usr/bin/tcpdump

I suggest you to ssh once into your machine to confirm the signature. Then you can run wireshark over the command and then enter the password to start tcpdump

ssh user@hackiebox sudo tcpdump -i ens19 -U -s0 -w - 'not port 22' | wireshark -k -i -

Certificates helpers (just for legacy reasons!) #

Certificate conversion #

To use the certificates and the rsa key with most tools you will need to convert it from DER to PEM

openssl x509 -inform DER -outform PEM -in ca.der -out ca.cer
openssl x509 -inform DER -outform PEM -in client.der -out client.cer
openssl rsa -inform DER -outform PEM -in private.der -out private.key

Generate self signed root CA #

openssl genrsa -out ca.key 4096
faketime '2015-11-04 00:00:00' openssl req -new -x509 -key ca.key -out ca.cer -days 9000 -subj '/C=DE/ST=NW/L=Duesseldorf/O=Boxine GmbH/CN=Boxine CA'

Generate domains certificates #

openssl req -new -key ca.key -out -subj '/C=DE/ST=NW/L=Duesseldorf/O=Boxine GmbH/'
openssl req -new -key ca.key -out -subj '/C=DE/ST=NW/L=Duesseldorf/O=Boxine GmbH/'
faketime '2015-11-05 00:00:00' openssl x509 -req -in -CA ca.cer -CAkey ca.key -set_serial 101 -days 10950 -outform PEM -out
faketime '2015-11-05 00:00:00' openssl x509 -req -in -CA ca.cer -CAkey ca.key -set_serial 101 -days 10950 -outform PEM -out

Generate client certificate #

openssl genrsa -out private.key 2048
openssl req -utf8 -new -key private.key -out client.req -subj '/C=DE/ST=NRW/L=Düsseldorf/O=Boxine GmbH'
openssl x509 -req -in client.req -CA ca.cer -CAkey ca.key -set_serial 101 -extensions client -days 10950 -outform PEM -out client.cer

Certificate conversion #

To use your generated certificates/ley for the toniebox you will have to convert it back to DER format.

openssl x509 -inform PEM -outform DER -in ca.cer -out ca.der
openssl x509 -inform PEM -outform DER -in client.cer -out client.der
openssl rsa -inform PEM -outform DER -in private.key -out private.der

Certificate upload #

cc3200tool -p COM6 write_file z:\fakessl\box_fake\client.der /cert/client.der write_file z:\fakessl\box_fake\private.der /cert/private.der write_file z:\fakessl\fake\ca.der /cert/ca.der

Concat certificates to PEM #

cat ca.key ca.cer > ca.pem
cat ca.key >
cat ca.key >