Thomas Nagy software pages

November 1, 2006

Crypto tools

#############################
# GNUPG
#############################

# generate a keypair
gpg --gen-key
# export ones public key
gpg --armor --output pubkey.txt --export 'My name'
# send the key on the server (easier with kgpg)
gpg --send-keys 'My name' --keyserver hkp://subkeys.pgp.net

# import someone else's key gpg --import key.asc gpg --search-keys 'tnagy1024@gmail.com' --keyserver hkp://subkeys.pgp.net # encrypt a file gpg --encrypt --recipient 'tnagy1024@gmail.com' foo.txt # decrypt a file gpg --output foo.txt --decrypt foo.txt.gpg


#############################

# LINUX

#############################
# partition creation using ‘dd’

dd if=/dev/urandom of=/root/linux.bin bs=1024k count=278

dd if=/dev/zero of=/root/linux.bin bs=1024k count=4489 (dvd R)

dd if=/dev/zero of=/root/linux.bin bs=1024k count=4450 (dvd RW)

dd if=/dev/zero of=/root/linux.bin bs=1024k count=700 (cdrom de 700 Mb)



# filesystem creation

mkfs -t ext2 /dev/loop0

tune2fs -m0 -c0 -i0 /dev/loop0
# script for mounting the volume

#! /bin/sh

DEVICE=/root/linux.bin

sudo /sbin/modprobe cryptoloop

sudo /sbin/modprobe aes

sudo /sbin/losetup -eaes256 -C7 /dev/loop0 $DEVICE

sleep 1

sudo mount /dev/loop0 /crypt
# script for unmounting

#! /bin/sh

sudo umount /crypt

sudo /sbin/losetup -d /dev/loop0
#############################

# SSH

#############################
# Key creation

ssh-keygen -t rsa
then copy ~/.ssh/id_rsa.pub on the remote server
# To avoid retyping the password over and over again, edit ~/.profile

SSHAGENT=/usr/bin/ssh-agent

SSHAGENTARGS="-s"

if [ -z "$SSH_AUTH_SOCK" -a -x "$SSHAGENT" ]; then

eval `$SSHAGENT $SSHAGENTARGS`

trap "kill $SSH_AGENT_PID" 0

fi


# for the fist time, call:

ssh-add ~/.ssh/id_dsa
#############################

# Links

#############################
IRC replacement : silcnet

librairies Bouncy Castle, Cryptlib

privacy Freenet, Tor