On Sun Aug 4, 2024 at 4:42 PM EEST, James Bottomley wrote: > The design of the intel-tss shim is to hide the difference between the > internal and the external handles by doing the internal to external > transform on entry. Unfortunately, the NULL handle (TPM_RH_NULL, > 40000007) has two possible internal representations depending on > whether it's used to indicate no session or the null hierarcy. > > There is a bug in the intel-tss in that it uses the wrong internal > NULL handle to try to create the NULL seed primary (and thus fails). > Now that we're going to be using the NULL primary to salt sessions, > the Intel TSS shim needs fixing to cope with thi correctly. > > The fix is to do the correct transform to the internal hierarchy > representation on NULL hierarchy creation and to do the session handle > conversion everywhere else. Additionally remove the intel_handle() > code which was supposed to do this: it's unused because 0 is never > passed in as a handle number. > > Signed-off-by: James Bottomley <[email protected]> > > --- > v2: reword commit message > > --- > src/include/intel-tss.h | 18 +++++------------- > 1 file changed, 5 insertions(+), 13 deletions(-) > > diff --git a/src/include/intel-tss.h b/src/include/intel-tss.h > index 1870b4e..5b8db20 100644 > --- a/src/include/intel-tss.h > +++ b/src/include/intel-tss.h > @@ -251,14 +251,6 @@ intel_sess_helper(TSS_CONTEXT *tssContext, > TPM_HANDLE auth, TPMA_SESSION flags) > TPMA_SESSION_CONTINUESESSION | > flags); > } > > -static inline TPM_HANDLE > -intel_handle(TPM_HANDLE h) > -{ > - if (h == 0) > - return ESYS_TR_NONE; > - return h; > -} > - > static inline void > TSS_Delete(TSS_CONTEXT *tssContext) > { > @@ -937,8 +929,10 @@ tpm2_CreatePrimary(TSS_CONTEXT *tssContext, > TPM_HANDLE primaryHandle, > TPM2B_PUBLIC *opub; > TPM_RC rc; > > - /* FIXME will generate wrong value for NULL hierarchy */ > - primaryHandle = intel_handle(primaryHandle); > + > + /* TPM_RH_NULL is mapped to ESYS_TR_NONE, which won't work > here */ > + if (primaryHandle == TPM_RH_NULL) > + primaryHandle = INT_TPM_RH_NULL; > > outsideInfo.size = 0; > creationPcr.count = 0; > @@ -993,9 +987,7 @@ tpm2_StartAuthSession(TSS_CONTEXT *tssContext, > TPM_HANDLE tpmKey, > TPM_HANDLE *sessionHandle, > const char *bindPassword) > { > - bind = intel_handle(bind); > - tpmKey = intel_handle(tpmKey); > - if (bind != ESYS_TR_NONE) > + if (bind != TPM_RH_NULL) > intel_auth_helper(tssContext, bind, bindPassword);
Not blaming the patch but just have hard time coping this. The most basic question is probably this: what is the application for INT_TPM_RH_NULL? Let's imagine that we have a flow chart describing Intel shim as a state machine. I decide to shoot it with these three stimulus: 1. INT_TPM_RH_NULL 2. TPM_RH_NULL 3. A valid handle What happens in each case to its state? > > return Esys_StartAuthSession(tssContext, tpmKey, bind, > ESYS_TR_NONE, BR, Jarkko
