common: add TPM vendor command to support RMA authentication

The new vendor command operates in two modes: when received with a
zero size payload, it triggers the Cr50 to generate a new RMA
authentication challenge and the expected authentication code value.

When receive with the payload, it compares the received payload with
the pre-calculate authentication code, and returns to the host the
comparison result (passed/not passed).

A care is taken not to accept payload until at least there is a valid
calculated auth code present (to avoid reporting a match on a payload
of all zeros).

Test config needed to be modified to allow compiling of the ccprintf
wrapper.

BRANCH=cr50
BUG=b:37952913
TEST=with the rest of the patches applied observed expected behavior
     of generating challenge/response and verifying the auth code.

Change-Id: I30638b0ceef68830565f222dd1f4af17cfc8d7ef
Signed-off-by: Vadim Bendebury <vbendeb@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/690992

1 files changed, 1 insertions, 0 deletions

diff --git a/include/tpm_vendor_cmds.h b/include/tpm_vendor_cmds.h
index 59331313d9..b46e0af754 100644
--- a/include/tpm_vendor_cmds.h
+++ b/include/tpm_vendor_cmds.h
@@ -43,6 +43,7 @@ enum vendor_cmd_cc {
 	VENDOR_CC_U2F_APDU = 27,
 	VENDOR_CC_POP_LOG_ENTRY = 28,
 	VENDOR_CC_GET_REC_BTN = 29,
+	VENDOR_CC_RMA_CHALLENGE_RESPONSE = 30,
 
 	LAST_VENDOR_COMMAND = 65535,
 };