SCP Hints

Just a few quick speed hints for using SCP, which came my way: The -C flag will tell SSH/SCP to compress stuff. In general I use it all the time. CPUs are so much faster than networks still so compression is your friend. Depending on your platform, using the blowfish cipher should be a little faster than using the default 3des or aes128 (don’t quote me on the aes128 claim, they’re both pretty close). Most people don’t realize, but you can configure all sorts of options on a global and a per host level in your ~/.ssh/config file. This is nice because you can force it to use a different port for certain hosts, different ciphers, not allow password, only forward X for some hosts, etc. Here’s a little snippet to drop in your ~/.ssh/config that will make you use blowfish for your cipher and compress all data going over the network with GZip at level 6. Host * Compression yes Ciphers blowfish-cbc,aes128-cbc,3des-cbc,cast128-cbc,arcfour,aes192-cbc,aes256-cbc I’m actually a little confused about why exactly this works, as the docs say it is only for SSH1 and not SSH2, but testing a 11 meg text file (about 20 copies of Huckleberry Finn repeated over and over), with compression gave me an overall throughput of 90.6K (11 megs in 1 minute, 51 seconds), without compression gave an overall throughput of 32.8K (11 megs in 4:58). Totally non-scientific, but good enough for me to conclude that it’s doing something, especially considering that my cable modem says that it’s current upstream rate 384000bps. At this point, I’ll also throw in a quick plug for using mod_gzip...

Open source in the police department

What I appreciate about this article over at RedHat (as I read): 1. This guy clearly will bounce between operating systems. He mentions “MSYS” (http://www.mingw.org/download.shtml) which also should be in one’s bag of tricks with cygwin. 2. He is willing to consider some old 8086 machines and dot-matrix printers as potential time-saving tools. 3. He mentions the Penguin Sleuthkit, which looks great as a forensic tool. It is incredibly important to use tools which protect the integrity of the scene — there can be no question of tampering with anything. This kit looks like it has the tools one would need to do a rapid...