mount truecrypt volumes using system encryption passphrase

From a previous Windows setup I have two Truecrypt encrypted harddrives. I can mount these without any problem during my fedora session with: sudo /sbin/cryptsetup open --type tcrypt /dev/sdb2 stuff sudo /sbin/cryptsetup open --type tcrypt /dev/sdb2 otherstuff I have automated this process with the help of . However, this is stil a bit tedious as I have to type the same passphrase is a bit long and I have to type it twice. I could just write a script storing my passphrase but this would be a vulnerability as the script can be read by anyone. I thought about storing the passphrase in the keyring, but I prefer not to save the passphrase on the pc. Additionally I have no Idea how to do this because I only found an [incomplete tutorial for Arch Linux](https://wiki.archlinux.org/index.php?title=Dm-crypt%2FMounting_at_login&type=revision&diff=425842&oldid=425740) . Since I use the same passphrase for the truecrypt drives as I do for the system drive, I wonder if I can mount these during startup with the passphrase to unlock the system partition. I run Fedora and any help is greatly appreciated! P.S. I have previously [asked this on Ask Fedora](http://ask.fedoraproject.org/en/question/93269/mount-truecrypt-volumes-using-system-encryption-passphrase/) with no response.