Patent ID: 11900127
Assignee: MICROSOFT TECHNOLOGY LICENSING, LLC
Field: Computer technology (Electrical engineering)
Classification: CPC G  H | IPC G  H

Claim 0:
1. A computer-implemented method, operable on a computing device having a processor supporting a secure execution environment in a secure enclave, comprising:
providing at least one security monitor configured for runtime introspection of a runtime state of the computing device;
providing at least one non-transitory computer-readable storage device storing code for an operating system (OS) thereon and including an isolated read-only partition storing a recovery OS thereon,
executing a trusted Unified Extensible Firmware Interface (UEFI) providing a runtime that executes System Management Mode (SMM) code from a hardware-protected System Management Random Access Memory (SMRAM);
executing the SMM code to instantiate a System Management Interrupt (SMI) handler that executes on the computing device to cause the computing device to reboot and be re-imaged from a trusted recovery operating system (OS);
initializing a UEFI enclave in the UEFI runtime as a pre-boot process on the computing device;
configuring an untrusted OS to initialize a deferral ticket minting enclave as a post-boot process on the computing device, in which the UEFI enclave and the deferral ticket minting enclave share a common enclave author, and in which the deferral ticket minting enclave is configured for minting a deferral ticket based on the runtime state, wherein presence of the deferral ticket causes the SMI handler to defer the reboot and re-imaging of the computing device; and
utilizing an enclave versioning support protocol by which enclaves having a common author are each enabled to provision a common symmetric key to provide cryptographic security for the deferral ticket.