The free FVP simulator can implement Pointer Authentication, but it defaults to an Implementation Defined algorithm. Specifically, ID_AA64ISAR1.API (bits 11:8) is non-0 indicating an IMPLEMENTATION DEFINED crypto algorithm is used. I've tried to turn on QARMA3 with cluster0.has_qarma3_pac=1, but this is ignored (since I assume the free FVP doesn't support it for some reason).
Can someone point me to a description of the pointer authentication algorithm the simulator is using? The Arm ARM gives the algorithm for QARMA3 and QARMA5 in the function ComputePACQARMA, so the algorithm should not need to be a secret (it's only in the FVP in any case).