I am using BeableBone Black devices running Debian which communicate securely with an AWS server over TLS using signed certificates.
I need to store my private keys securely on the devices. The best way to store these is by using a separate hardware security module or TPM connected to the BeagleBone which I don't have just yet.
Just by using the available flash memory, what would be the most secure way that I can store the keys? My applications will of course need access to the keys without any user intervention.
Does encrypting the keys make any sense, for example by using dm-crypt? Decryption of the keys I guess will require a password, but then this password must be stored securely too? What about an encrypted partition?