2009/2/19 phcoder <phco...@gmail.com>: > First of all your system is still totally vulnerable to emanation and power > analysis or hw tampering. By reflashing bios one can bypass all tpm > protections (don't say it's difficult because it's closed source and so on. > Look at all closed source obfuscations/pseudo-protections that get cracked > every day)
This is interesting. I have not thought about the way the BIOS is protected from tampering. You can probably read the BIOS and verify the signature with the TPM chip but there is nothing that can attest the machine actually used this BIOS for booting. Since the BIOS is not stored in the TPM chip and must be able to reset the TPM chip into a good state at least when the power is removed from the board it must be possible to not use the BIOS at all and leave the TPM chip in good or resettable state. The hard part is initializing the hardware without the use of the original BIOS - the specifics of initializing various chips are not public, and probably depend on companion hardware and/or trace length on the particular board as well. Thanks Michal _______________________________________________ Grub-devel mailing list Grub-devel@gnu.org http://lists.gnu.org/mailman/listinfo/grub-devel
