Method to securely transfer root of trust responsibilities on a common shared motherboard
In general, embodiments of the invention relate to implementing a secure boot process in information handling systems that supports both an external root of trust (eRoT) and an internal root of trust (RoT). Further, embodiments of the invention relate to binding a management controller to a specific chassis and, in the case where the eRoT is used, to an eRoT. When the management controller and the chassis are provisioned according to one or more embodiments of the invention, security checks may be performed by management controller executing an initial program loader (IPL) using the aforementioned bindings. If the bindings are not present or do not match, then the boot process halts and the user is unable to use the information handling system.
1. An information handling system, comprising:
a chassis comprising chassis storage; and
a motherboard located within the chassis comprising a management controller, wherein the management controller comprises controller storage,
wherein the controller storage comprises a unique encryption key and a root of trust (RoT) identifier,
wherein the chassis storage comprises an encrypted value generated by encrypting the RoT identifier with the unique encryption key,
wherein the management controller is programmed to:
after being powered on and prior to initiating a boot loader:
requesting the encrypted value from the chassis storage;
receiving the encrypted value from the chassis storage;
decrypting the encrypted value for the chassis storage using the unique encryption key to obtain a decrypted value; and
initiating the boot loader when the decrypted value equals the RoT identifier.
2. The information handling system of claim 1 , further comprising:
a RoT that generated the RoT identifier,
wherein the RoT is operatively connected to the management controller, and
wherein the RoT identifier is unique to the RoT.
3. The information handling system of claim 2 , wherein the RoT is located on the management controller.
4. The information handling system of claim 2 , wherein the RoT is located on the motherboard and external to the management controller.
5. The information handling system of claim 2 , wherein the management controller is programmed to:
after being powered on and prior to initiating the boot loader:
requesting the RoT identifier from the RoT;
receiving, in response to the request, a response value from the RoT; and
determining whether the RoT identifier stored in the controller storage matches the response value.
6. The information handling system of claim 5 , wherein the management controller is further programmed to:
stop further bootup of the information handling system when the RoT identifier stored in the controller storage does not match the response value.
7. The information handling system of claim 5 , wherein the management controller is further programmed to:
when the RoT identifier stored in the controller storage matches the response value:
requesting the encrypted value from the chassis storage;
receiving the encrypted value from the chassis storage;
decrypting the encrypted value for the chassis storage using the unique encryption key to obtain a second decrypted value; and
initiating execution of the boot loader when the second decrypted value equals the RoT identifier.
8. The information handling system of claim 1 , wherein the chassis storage is one-time programmable storage and is not located on the motherboard.
9. The information handling system of claim 8 wherein the controller storage is one-time programmable storage and is located on the motherboard.
10. The information handling system of claim 1 , wherein the unique encryption key is unique to the management controller.
11. The information handling system of claim 1 , wherein the management controller is a baseboard management controller.
12. A method for securely booting an information handling system comprising a chassis and a management controller, the method comprising:
after being powered on and prior to initiating a boot loader:
requesting, by the management controller, a root of trust (RoT) identifier from a RoT;
receiving, in response to the request, a response value from the RoT;
determining, by the management controller, that the RoT identifier stored in a controller storage matches the response value;
based on the determination:
requesting an encrypted value from a chassis storage located in the chassis;
receiving the encrypted value from the chassis storage;
decrypting the encrypted value for the chassis storage using a unique encryption key to obtain a decrypted value; and
initiating the boot loader when the decrypted value equals the RoT identifier.
13. The method of claim 12 , further comprising:
prior to requesting, by the management controller, the RoT identifier from the RoT, provisioning the information handling system, wherein the provisioning comprises:
requesting, by the management controller, the RoT identifier from the RoT;
receiving, in response to the request, the RoT identifier from the RoT;
fusing the RoT identifier to the management controller;
encrypting the RoT identifier using the unique encryption key to obtain the encrypted value; and
initiating the fusing of the encrypted value to the chassis storage.
14. The method of claim 13 ,
wherein the controller storage is a first one-time programmable storage and is located on a motherboard in the chassis; and
wherein the chassis storage is a second one-time programmable storage and is not located on the motherboard.
15. The method of claim 13 , wherein the unique encryption key is unique to the management controller.
16. The method of claim 13 , wherein the management controller is a baseboard management controller.
17. The method of claim 13 , wherein the RoT is located on the management controller.
18. The method of claim 13 , wherein the RoT is located on a motherboard in the chassis and external to the management controller.
19. The method of claim 13 , wherein the RoT identifier that is stored in the controller storage cannot be changed after the fusing.