I have setup my fedora to use LUKS encryoted partitions. But entering two passwords gets quite tiring, as I shutdown my laptop quite often to get the benefit of LUKS (I am assuming nothing is encrypted when in suspend, please correctme if I am wrong)
I am thinking about setting up TPM autodecrypt. However, I was wondering does the decryption happen on boot or after I login?
If it happens on boot, then it seems like the benefit is pretty limited compare to a unencrypted drive. Since the attacker can simply boot my laptop and get the unecrypted drive.
Am I missing something here? I was wondering is there a way for me to enter my password once and unlock everything, from disk to gnome keyring?
The TPM releases the key to the OS at boot time. Without that, there would be no way for the OS to load (assuming the root FS is encrypted).
The key is bound to PCRs in the TPM, which control under what conditions the key can be released. For example, it can be tied to secure boot, bios settings, etc.