Skip to main content

Add encryption key to device after installation

I started to use encryption on my drives during installation (and also with external drives).  As ironic as this sounds:  I'm sick of entering my encryption pass-phrase every time I boot my laptop.  Even though what I am about to do is *less* secure, I still think it makes my machine pretty damn secure yet.
I am preventing someone from stealing my laptop and pulling the drive to get my data.  Yes, the machine boots - which means they either have to brute-force a login at the console, or hack a service once the machine is up.  At that point, they almost deserve my "sensitive data"...

Anyhow - if you would like to use encryption on your OS drive, but do not want to enter a passphrase, do the following:

dd if=/dev/urandom of=/root/.keyfile bs=32 count=1
chmod 0600 /root/.keyfile
cryptsetup luksAddKey /dev/sda4 /root/.keyfile
sed -i -e 's/none/\/root\/.keyfile/g' /etc/crypttab
dracut --force --install /root/.keyfile /boot/initramfs-`uname -r`.img

# SPECIAL CASE(S)
If you can't use the "whole device" (i.e. sda4 in this example)
run
[root@neo ~]# lsblk
NAME                                            MAJ:MIN RM   SIZE RO TYPE  MOUNTPOINT
sda                                               8:0    0 223.6G  0 disk 
├─sda1                                            8:1    0   100M  0 part  /boot/efi
├─sda2                                            8:2    0   128M  0 part 
├─sda3                                            8:3    0 104.2G  0 part  /windows/C
├─sda4                                            8:4    0   256M  0 part  /boot
└─sda5                                            8:5    0  97.2G  0 part 
  ├─fedora-01                                   253:0    0  93.1G  0 lvm  
  │ └─luks-9d8c2cdc-aa74-4710-abc8-81f045573401 253:3    0  93.1G  0 crypt /
  └─fedora-00                                   253:1    0     4G  0 lvm  
    └─luks-5b9faf52-9831-4fe1-803b-750877c743e3 253:2    0     4G  0 crypt [SWAP]
mmcblk0                                         179:0    0 119.3G  0 disk 
└─mmcblk0p1                                     179:1    0 119.3G  0 part  /X1CARBON
cryptsetup luksAddKey /dev/mapper/fedora-00 /root/.keyfile
cryptsetup luksAddKey /dev/mapper/fedora-01 /root/.keyfile


# dracut --force --install /root/.keyfile /boot/initramfs-3.15.8-200.fc20.x86_64.img

Labels:

Comments

Post a Comment

Popular posts from this blog

P2V using dd for KVM-QEMU guest

Preface: I have certainly not exhaustively tested this process.  I had a specific need and found a specific solution that worked. Situation:  I was issued a shiny new laptop running Red Hat Enterprise Linux 7 (with Corp VPN, certs, Authentication configuration, etc...)  The image was great, but I needed more flexibility on my bare metal.  So, my goal was to P2V the corporate image so I could just run it as a VM. * Remove corporate drive and install new SSD * install corp drive in external USB-3 case * Install RHEL 7 on new SSD * dd old drive to a disk-image file in a temp location which will be an image which is the same size as your actual drive (unless you have enough space in your destination to contain a temp and converted image) * convert the raw disk-image to a qcow file while pushing it to the final location - this step should reduce the disk size - however, I believe it will only reduce/collapse zero-byte blocks (not just free space - i.e. if you de...
1 comment
Read more

Sun USS 7100 foo

TIP: put ALL of your LUNs into a designated TARGET and INITIATOR group when you create them.  If you leave them in the "default" group, then everything that does an discovery against the array will find them :-( I'm struggling to recognize a reason that a default should even be present on the array. Also - who, exactly, is Sun trying to kid.  The USS is simply a box.. running Solaris .. with IPMP and ZFS.  Great.  If you have ever attempted to "break-in" or "p0wn" your IBM HMC, you know that there are people out there that can harden a box - then.. there's Sun.  After a recent meltdown at the office I had to get quite intimate with my USS 7110 and learned quite a bit.  Namely: there's a shell ;-) My current irritation is how they attempt to "warn you" away from using the shell (my coverage expired a long time ago to worry about that) and then how they try to hide things, poorly. I was curious as to what version of SunOS it ...
1 comment
Read more

Extending SNMP to run arbitrary shell script

Why are we here... This is not likely something I would have pursued under normal circumstances.  I happen to be working for a customer/client who is not afforded a lot of flexibility to accomplish their goals.  In this case, the rigor is justified.  They have to sometimes be fairly creative with how they solve problems. In this case they would like to utilize an existing snmp implementation to execute a command (or shell script) on a remote system.  They came to me with the idea of using Net-SNMP extend. https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/6/html/Deployment_Guide/sect-System_Monitoring_Tools-Net-SNMP-Extending.html NOTE:  This is NOT a good implementation strategy in the "real world"  it will simply allow you to test the functionality.  There are a TON of security implications which would need to be taken in to consideration. Implementation Steps: [root@rh7tst01 ~]# yum -y install net-snmp net-snmp-utils ...
Post a Comment
Read more