tpm: fix RC value check in tpm2_seal_trusted
The error code handling is broken as any error code that has the same
bits set as TPM_RC_HASH passes. Implemented tpm2_rc_value() helper to
parse the error value from FMT0 and FMT1 error codes so that these types
of mistakes are prevented in the future.
Fixes: 5ca4c20cfd37 ("keys, trusted: select hash algorithm for TPM2 chips")
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Reviewed-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
index 244fcff..dbe0c5a 100644
--- a/drivers/char/tpm/tpm.h
+++ b/drivers/char/tpm/tpm.h
@@ -519,6 +519,11 @@
}
#endif
+static inline inline u32 tpm2_rc_value(u32 rc)
+{
+ return (rc & BIT(7)) ? rc & 0xff : rc;
+}
+
int tpm2_pcr_read(struct tpm_chip *chip, int pcr_idx, u8 *res_buf);
int tpm2_pcr_extend(struct tpm_chip *chip, int pcr_idx, const u8 *hash);
int tpm2_get_random(struct tpm_chip *chip, u8 *out, size_t max);