Set buffer pointer before parsing ASN1
Set buffer pointer before parsing ASN1

Thanks OSS-Fuzz
https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=49248

mouse07410/OpenSC,LudovicRousseau/OpenSC,LudovicRousseau/OpenSC,metsma/OpenSC,philipWendland/OpenSC,dengert/OpenSC,philipWendland/OpenSC,OpenSC/OpenSC,philipWendland/OpenSC,metsma/OpenSC,mouse07410/OpenSC,mouse07410/OpenSC,LudovicRousseau/OpenSC,dengert/OpenSC,dengert/OpenSC,OpenSC/OpenSC,metsma/OpenSC,OpenSC/OpenSC