Data structure measurement comparison
A system comprising an inner kernel of an operating system (OS) running at a higher privilege level than an outer kernel of the OS, the inner kernel to measure a data structure in a memory; a device including a measurement engine to measure the data structure in the memory, wherein the device operates independently of the OS; and a trusted execution environment including an application to compare measurements from the inner kernel and the measurement engine.
1. A system comprising:
a trusted application environment including an application;
an inner kernel of an operating system (OS) running at a higher privilege level than an outer kernel of the OS, the inner kernel includes machine-readable instructions that, when executed, measure a data structure in a memory space that the inner kernel occupies to provide a first measurement; and
a device including a measurement engine to measure the memory space, wherein the device operates independently of the OS and the device to, in response to requests from the application at different times, send second measurements of the memory space to the application;
wherein the application to:
provide the requests to the device;
compare the first measurement to the second measurements; and
initiate remedial action based on the comparison.
2. The system of claim 1 , wherein the device is a baseboard management controller (BMC).
3. The system of claim 1 , wherein the device receives an address corresponding to the memory space from the application.
4. The system of claim 1 , wherein the measurement engine continuously measures the memory space.
5. The system of claim 1 , wherein, in response to a given second measurement of the second measurements not matching the first measurement, the device performs the remedial action.
6. The system of claim 5 , wherein the remedial action includes a system restart with a known good image.
7. The system of claim 1 , wherein the application sends a heartbeat signal to the device.
8. The system of claim 7 , wherein, in response to a failure to receive a heartbeat signal within a timeout period, the device takes the remedial action.
9. The system of claim 1 , wherein the device authenticates that the application is genuine at startup and at periodic intervals.
10. The system of claim 1 , wherein the inner kernel is static and the outer kernel is a self-modifying kernel.
11. The system of claim 1 , wherein the first measurement comprises a hash of a region of the memory space.