diff --git a/src/shared/tpm2-util.c b/src/shared/tpm2-util.c index 7c9eb77f95..ba2120065a 100644 --- a/src/shared/tpm2-util.c +++ b/src/shared/tpm2-util.c @@ -924,6 +924,18 @@ static int tpm2_make_policy_session( log_debug("Starting authentication session."); + /* So apparently some TPM implementations don't implement trial mode correctly. To avoid issues let's + * avoid it when it is easy to. At the moment we only really need trial mode for the signed PCR + * policies (since only then we need to shove PCR values into the policy that don't match current + * state anyway), hence if we have none of those we don't need to bother. Hence, let's patch in + * TPM2_SE_POLICY even if trial mode is requested unless a pubkey PCR mask is specified that is + * non-zero, i.e. signed PCR policy is requested. + * + * One day we should switch to calculating policy hashes client side when trial mode is requested, to + * avoid this mess. */ + if (session_type == TPM2_SE_TRIAL && pubkey_pcr_mask == 0) + session_type = TPM2_SE_POLICY; + if ((hash_pcr_mask | pubkey_pcr_mask) != 0) { /* We are told to configure a PCR policy of some form, let's determine/validate the PCR bank to use. */