VerifySignature can be implemented using a mirror of the AuthenticodeVerify function that's already in use in the ImageVerificationDXE environment, so this patch simply wires up VerifySignature using that code. <NOTE: Only Authenticode-signature verification was supported by this VerifySignature() implementation now.) Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com> Reviewed-by: Long Qin <qin.long@intel.com>