Get cryptsetup working without typing a password

Question

I have used cryptsetup to encrypt an external hard drive.

I have no problem at using the encrypted hard drive in this way:

/sbin/cryptsetup luksOpen /dev/sdc1 backup   
// typing password   
// mounting the partition   
// doing something   
// unmounting the partition  
/sbin/cryptsetup luksClose /dev/mapper/backup

But my next requirement was to be able to do it without the need of typing a password.

Then I created a binary file with the hash of my password via this command:

hashalot -n 32 ripemd160 > volume_key 

and then:

/sbin/cryptsetup luksOpen -d volume_key /dev/sdc1 backup

but I get this error:

Command failed: No key available with this passphrase.

Any ideas guys?

Answer 1

The contents of the volume_key file will be hashed by cryptsetup, so you don't need to do that yourself?

Answer 2

cryptsetup man page suggests the following about the -d parameter: "If you want to set a new key via a key file, you have to use a positional arg to luksFormat or luksAddKey."