By now, everybody knows we have a problem with the TPM2_RS_PW easy button on TPM2 in that transactions on the TPM bus can be intercepted and altered. The way to fix this is to use real sessions for HMAC capabilities to ensure integrity and to use parameter and response encryption to ensure confidentiality of the data flowing over the TPM bus. This RFC is about adding a simple API which can ensure the above properties as a layered addition to the existing TPM handling code. Eventually we can add this to the random number generator, the PCR extensions and the trusted key handling, but this all depends on the conversion to tpm_buf which is not yet upstream, so I've constructed a second patch which demonstrates the new API in a test module for those who wish to play with it. This series is also dependent on additions to the crypto subsystem to fix problems in the elliptic curve key handling and add the Cipher FeedBack encryption scheme: https://marc.info/?l=linux-crypto-vger&m=151994371015475 In the second version, I added security HMAC to our PCR extend and encryption to the returned random number generators and also extracted the parsing and tpm2b construction API into a new file. James --- James Bottomley (5): tpm-buf: create new functions for handling TPM buffers tpm2-sessions: Add full HMAC and encrypt/decrypt session handling tpm2: add hmac checks to tpm2_pcr_extend() tpm2: add session encryption protection to tpm2_get_random() tpm2-sessions: NOT FOR COMMITTING add sessions testing drivers/char/tpm/Kconfig | 3 + drivers/char/tpm/Makefile | 3 +- drivers/char/tpm/tpm-buf.c | 184 ++++++ drivers/char/tpm/tpm-chip.c | 1 + drivers/char/tpm/tpm.h | 116 ++-- drivers/char/tpm/tpm2-cmd.c | 129 ++--- drivers/char/tpm/tpm2-sessions-test.c | 177 ++++++ drivers/char/tpm/tpm2-sessions.c | 1030 +++++++++++++++++++++++++++++++++ drivers/char/tpm/tpm2-sessions.h | 56 ++ 9 files changed, 1548 insertions(+), 151 deletions(-) create mode 100644 drivers/char/tpm/tpm-buf.c create mode 100644 drivers/char/tpm/tpm2-sessions-test.c create mode 100644 drivers/char/tpm/tpm2-sessions.c create mode 100644 drivers/char/tpm/tpm2-sessions.h -- 2.12.3
