tree 89cd1acb780ee57bb744d3f1684d72ac07075fd0
parent 448d1cc854237feca7412bae2e0c1c99de5b6999
author Gilles Peskine <Gilles.Peskine@arm.com> 1579534266 +0100
committer Gilles Peskine <Gilles.Peskine@arm.com> 1579534266 +0100

Fix possible error code mangling in psa_mac_verify_finish

If psa_mac_finish_internal fails (which can only happen due to bad
parameters or hardware problem), the error code was converted to
PSA_ERROR_INVALID_SIGNATURE if the uninitialized stack variable
actual_mac happened to contain the expected MAC. This is a minor bug
but it may be possible to leverage it as part of a longer attack path
in some scenarios.

Reported externally. Found by static analysis.