Jul 08

sslsnoop – hacking OpenSSH

Reading time: < 1 minute

Using sslsnoop you can dump SSH keys used in a session and decode ciphered traffic. Supported algorithms are: aes128-ctr, aes192-ctr, aes256-ctr, blowfish-cbc, cast128-cbc.

Basic sslsnoop information:

 $ sudo sslsnoop # try ssh, sshd and ssh-agent… for various things
 $ sudo sslsnoop-openssh live `pgrep ssh` # dumps SSH decrypted traffic in outputs/
 $ sudo sslsnoop-openssh offline –help # dumps SSH decrypted traffic in outputs/ from a pcap file
 $ sudo sslsnoop-openssl `pgrep ssh-agent` # dumps RSA and DSA keys

Take a look into the project in sslsnoop github page.

Jun 30

Enabling linux kernel to open LOTS of concurrent connections

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Just a small recipe about how to enable linux kernel to open tons of concurrent connections. Really simple and useful post entry.

echo “10152 65535″ > /proc/sys/net/ipv4/ip_local_port_range
sysctl -w fs.file-max=128000
sysctl -w net.ipv4.tcp_keepalive_time=300
sysctl -w net.core.somaxconn=250000
sysctl -w net.ipv4.tcp_max_syn_backlog=2500
sysctl -w net.core.netdev_max_backlog=2500
ulimit -n 10240
May 19

Firmware of my home heaters (Panstamp = Arduino + TI C1101)

This entry is part 3 of 3 in the series heater

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Clicking the next link you can get my github repository with the firmware of my home heaters. The code is very simple but useful as we tested last winter at home.

I know all the public documentation is not enough to duplicate my heating project. I’m so sorry but I have a lot of pending home projects to do because I have a lot of under construction things. If you need some help to understand what I have or how to do something feel free to ask.

 

Jan 30

USB 2.0 VGA from DealExtreme

Reading time: 1 – 2 minutes

Several months ago I bought a video graphics adapter for USB 2.0 port. It’s compatible with Linux, Mac and Windows but for a while I’ve only used it with Windows where it works as a extended screen for my HDMI main display. It works very good with 1920×1080 pixels resolution and it can play videos fast enough using a standalone video player or HTML5 video streaming from the internet.

The chipset used by this product is DISPLAYLINK DL-165 with DVI, HDMI and VGA adapters. It is powered by USB port with 5V DC and 450mA about 2,25W of consumption; but after installing the display driver I lost 2GB of RAM, which in my case it isn’t a problem but sometimes it could be a handicap.

USB 2.0 VGA

USB 2.0 VGA

If you are interested in this product I bought it in DealExtreme webpage, the product page is here and costs 34,28€ with free shipping.

Jan 29

Routerboard CRS125-24G-1S-2HnD-IN (Mikrotik) Cloud Switch

Reading time: 1 – 2 minutes

I bought this product a few weeks ago and finally I can enjoy it at home. With this product you have a firewall, gateway, switch and wireless box with:

  • 25x Gigabit Ethernet ports
  • 1x Fiber channel
  • 3G, 4G or any optional USB modem
  • With RouterOS inside you can manage: gateway, firewall, VPN and ad-hoc switching and routing configurations
  • 1000mW high power 2.4GHz 11n wireless AP
CRS125-24G-1S-2HnD-IN

CRS125-24G-1S-2HnD-IN

The official product page is here where you can find brochure in PDF and other useful information.

If you are looking for a powerful product for your SOHO network this is the solution as I like to say ‘this is one of the best communications servers’. It will be very difficult to find some feature or functionality that you can not get from this product. The product is robust and stable with the flexibility of RouterOS.

Jan 24

Conferència: La revolució dels mini-PC: Raspberry PI, Arduino i més

Reading time: 1 – 2 minutes

Ahir al vespre vaig fer una conferència a la FIB (Facultat d’Informàtica de Barcelona) dins de la UPC (Universitat Politècnica de Catalunya). En aquesta xerra vaig estar explicant què és i en que es diferència Arduino i Raspberry PI. A més de presentar tot un conjunt de solucions alternatives i experiències en el tema.

En aquest enllaç podeu trobar les transparències de:  La revolució dels mini-PC: Raspberry PI, Arduino i més. i el video el teniu disponible al servidor de la FIB.

Ara també teniu disponible el video a youtube:

i podeu veure les transparències des d’aquest mateix post:

Espero els vostres feedbacks als comentaris, desitjo que ús sigui útil.