I have bought a TPM module for the PcEngines APUs that are installed in the motherboard’s LPC interface and now correctly in the BIOS the interface to configure the TPM appears but doing tests in the IPFire, I see that it does not detect the TPM.
[root@ipfire ~]# /usr/sbin/rngd
Initalizing available sources
Failed to init entropy source 1: TPM RNG Device
Failed to init entropy source 2: Intel RDRAND Instruction RNG
[root@ipfire ~]#
But first of all a question, the TPM is a source of entropy, isn’t it?
This is clear dangerous half knowledge!
mknod /dev/tpm0 c 1 9
Creates a devnode that points to the urandom driver not to the tpm module (the devicenode is not created because the IPFire kernel has no driver/support for tpm modules).
You seed the random generator with its own output wich is not random!!!