This series of patches extends the TPM2 code to extend the BIOS related PCRs 0-7 in all available banks. This prevents that these PCRs remain untouched and filled with bogus values by applications. For example, the SHA1 hash is extended into the SHA256 bank. The value that is extended into this bank is essentially a SHA1 with zero bytes used for filling it to the size of a sha256 hash. This is done for all PCR banks of the TPM2 where these PCRs are available.
Stefan Berger (3): tpm: Retrieve the PCR Bank configuration tpm: Restructure tpm20_extend to use buffer and take hash as parameter tpm: Extend tpm20_extend to support extending to multiple PCR banks
src/std/tcg.h | 45 +++++++++++++-- src/tcgbios.c | 175 +++++++++++++++++++++++++++++++++++++++++++++++++++++----- 2 files changed, 201 insertions(+), 19 deletions(-)