Granted Patent B2

US 11,232,210 · App. 16/365,346 · Granted Jan 25, 2022

Inventor: Tino Lin (Irvine, CA)

Assignee: Western Digital Technologies, Inc.

G06F21/572G06F21/575H04L9/0631H04L9/0643

Abstract

Claims (92)

1. A direct-attached storage device bridge comprising:

a memory configured to store a firmware image to boot a device;

a read-only memory configured to store a public key; and

logic to, responsive to powering on the direct-attached storage device bridge:

access the firmware image in the memory, wherein the firmware image comprises:

an encrypted hash code;

encrypted firmware instructions; and

firmware instructions stored as clear-text;

use the public key to decrypt the encrypted hash code into a decrypted hash code;

use the public key to decrypt the encrypted firmware instructions into decrypted firmware instructions;

calculate a first calculated hash code of the decrypted firmware instructions;

calculate a second calculated hash code for the firmware instructions stored as clear-text;

compare the decrypted hash code, the first calculated hash code, and the second calculated hash code;

determine, based on the comparison of the decrypted hash code, the first calculated hash code, and the second calculated hash code, a firmware boot decision; and

boot, based on the firmware boot decision, the device using the clear-text firmware instructions.

2. The direct-attached storage device bridge of claim 1 , further comprising:

a FLASH memory separate from the read-only memory, the FLASH memory configured to store an index; and

logic to apply the index to identify the public key from a plurality of public keys stored in the read-only memory.

3. The direct-attached storage device bridge of claim 1 , wherein the firmware boot decision includes booting the device with no warnings on condition of any one of the following:

the decrypted hash code, the first calculated hash code, and the second calculated hash code are all equal to one another;

the decrypted hash code and the second calculated hash code are equal to one another, the decrypted hash code is not equal to the first calculated hash code, and the second calculated hash code is not equal to the first calculated hash code; and

the decrypted hash code and the first calculated hash code are equal to one another, the decrypted hash code is not equal to the second calculated hash code, and the second calculated hash code is not equal to the first calculated hash code.

4. The direct-attached storage device bridge of claim 1 , wherein the firmware boot decision includes booting the device with a warning on condition that:

the second calculated hash code is equal to the first calculated hash code; and

the decrypted hash code is not equal to the first calculated hash code or equal to the second calculated hash code.

5. The direct-attached storage device bridge of claim 4 , wherein the warning is a warning that the encrypted firmware instructions are compromised.

6. The direct-attached storage device bridge of claim 1 , wherein the firmware boot decision comprises performing a firmware repair on condition that:

the decrypted hash code and the first calculated hash code are equal to one another;

the decrypted hash code is not equal to the second calculated hash code; and

the second calculated hash code is not equal to the first calculated hash code.

7. The direct-attached storage device bridge of claim 1 , wherein the firmware boot decision comprises inhibiting booting the device on condition that:

the decrypted hash code, the first calculated hash code, and the second calculated hash code are all different from one another.

8. A system comprising:

means for storing a firmware image, wherein the firmware image comprises:

an encrypted hash block;

encrypted firmware instructions; and

firmware instructions stored as clear-text;

means for booting a device using the firmware image;

read-only memory configured to store a public key; and

means for validating the firmware image, wherein the means for validating is configured to, responsive to powering on and prior to booting the device:

use the public key to decrypt the encrypted hash block into a decrypted hash code and a symmetric key;

use the symmetric key to decrypt the encrypted firmware instructions into decrypted firmware instructions;

calculate a first calculated hash code of the decrypted firmware instructions;

calculate a second calculated hash code for the firmware instructions stored as clear-text;

compare the decrypted hash code, the first calculated hash code, and the second calculated hash code;

determine, based on the comparison of the decrypted hash code, the first calculated hash code, and the second calculated hash code, a firmware boot decision; and

initiate the means for booting the device based on the firmware boot decision.

9. The system of claim 8 , further comprising:

additional memory means separate from the read-only memory, wherein:

the additional memory means is configured to store an index; and

the means for validating the firmware image is configured to use the index to identify the public key from a plurality of public keys stored in the read-only memory.

10. The system of claim 8 , wherein the means for validating the firmware image is configured to initiate the means for booting the device with no warnings on condition of any one of the following:

the decrypted hash code, the first calculated hash code, and the second calculated hash code are all equal to one another;

the decrypted hash code and the second calculated hash code are equal to one another, the decrypted hash code is not equal to the first calculated hash code, and the second calculated hash code is not equal to the first calculated hash code; and

the decrypted hash code and the first calculated hash code are equal to one another, the decrypted hash code is not equal to the second calculated hash code, and the second calculated hash code is not equal to the first calculated hash code.

11. The system of claim 8 , wherein the means for validating the firmware image is configured to initiate the means for booting the device with a warning on condition that:

the second calculated hash code is equal to the first calculated hash code; and

the decrypted hash code is not equal to the first calculated hash code or equal to the second calculated hash code.

12. The system of claim 11 , wherein the warning is a warning that the symmetric key may be compromised.

13. The system of claim 8 , further comprising:

means for performing a firmware repair, wherein the means for validating the firmware image is configured to initiate the means for performing the firmware repair on condition that:

the decrypted hash code and the first calculated hash code are equal to one another;

the decrypted hash code is not equal to the second calculated hash code; and

the second calculated hash code is not equal to the first calculated hash code.

14. The system of claim 8 , wherein the means for validating the firmware image is configured to inhibit operation of the means for booting the device on condition that:

the decrypted hash code, the first calculated hash code, and the second calculated hash code are all different from one another.

15. A method for booting a device using a firmware image, the method comprising:

storing the firmware image in a storage device, the firmware image comprising:

an encrypted hash code;

encrypted firmware instructions; and

firmware instructions stored as clear-text; and

powering on the storage device and responsive to powering on the storage device, executing the following:

using a public key from a read-only memory to decrypt the encrypted hash code into a decrypted hash code;

using the public key to decrypt the encrypted firmware instructions into decrypted firmware instructions;

calculating a first calculated hash code of the decrypted firmware instructions;

calculating a second calculated hash code for the firmware instructions stored as clear-text;

comparing the decrypted hash code, the first calculated hash code, and the second calculated hash code;

determining, based on the comparison of the decrypted hash code, the first calculated hash code, and the second calculated hash code, a firmware boot decision; and

booting, based on the firmware boot decision, the device using the clear-text firmware instructions.

16. The method of claim 15 , further comprising:

applying an index stored in a FLASH memory separate from the read-only memory to identify the public key from a plurality of public keys stored in the read-only memory.

17. The method of claim 15 , wherein the firmware boot decision includes booting the device with no warnings on condition of any one of the following:

the decrypted hash code, the first calculated hash code, and the second calculated hash code are all equal to one another;

the decrypted hash code and the second calculated hash code are equal to one another, the decrypted hash code is not equal to the first calculated hash code, and the second calculated hash code is not equal to the first calculated hash code; and

the decrypted hash code and the first calculated hash code are equal to one another, the decrypted hash code is not equal to the second calculated hash code, and the second calculated hash code is not equal to the first calculated hash code.

18. The method of claim 15 , wherein the firmware boot decision includes booting the device with a warning on condition that:

the second calculated hash code is equal to the first calculated hash code; and

the decrypted hash code is not equal to the first calculated hash code or equal to the second calculated hash code.

19. The method of claim 15 , further comprising performing a firmware repair on condition that:

the decrypted hash code and the first calculated hash code are equal to one another;

the decrypted hash code is not equal to the second calculated hash code; and

the second calculated hash code is not equal to the first calculated hash code.

Assignments (10)

Continuity (1)

Cited By (2)

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