Address validation using signatures

• US 10,027,666 B2
• Filed: 07/27/2017
• Issued: 07/17/2018
• Est. Priority Date: 05/20/2015
• Status: Active Grant

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: Google LLC (Alphabet Inc.)
• Inventors: Serebrin, Benjamin C.
• Primary Examiner(s): Parsons, Theodore C.
• Assistant Examiner(s): Stoica, Adrian
• Application Number:
  US15/661,632
• Publication Number:
  US 20170339145A1
• Time in Patent Office: 355 Days
• CPC Class Codes: G06F 12/1081 for peripheral access to main memory, e.g. direct memory access [DMA]
• CPC Class Codes: G06F 12/1408 by using cryptography for digital transmission H04L9/00
• CPC Class Codes: G06F 12/1475 in a virtual system, e.g. with translation means
• CPC Class Codes: G06F 21/79 in semiconductor storage media, e.g. directly-addressable memories
• CPC Class Codes: G06F 2212/1052 Security improvement
• CPC Class Codes: H04L 63/062 for key distribution, e.g. centrally by trusted party cryptographic mechanisms or cryptographic arrangements for key distribution involving a central third party H04L9/0819
• CPC Class Codes: H04L 63/0876 based on the identity of the terminal or configuration, e.g. MAC address, hardware or software configuration or device fingerprint
• CPC Class Codes: H04L 63/164 at the network layer
• CPC Class Codes: H04L 9/3247 involving digital signatures

Abstract

Methods, systems, and apparatus, including computer programs encoded on computer storage media, for generating signed addresses. One of the methods includes receiving, by a component from a device, a plurality of first requests, each first request for a physical address and including a virtual address, determining, by the component, a first physical address using the virtual address, generating a first signature for the first physical address, and providing, to the device, a response that includes the first signature, receiving, from the device, a plurality of second requests, each second request for access to a second physical address and including a second signature, determining, by the component for each of the plurality of second requests, whether the second physical address is valid using the second signature, and for each second request for which the second physical address is determined to be valid, servicing the corresponding second request.

Claims

1. A computer-implemented method comprising:

receiving, by a component from a device, a request that includes a physical address and an error-detecting code value and that requests access to a memory location identified by the physical address;

in response to receiving the request, generating, by the component, a signature for the physical address using the physical address, wherein the request does not include the signature and the error-detecting code value was previously generated using the signature;

in response to generating the signature, generating a second error-detecting code value using the request and the signature;

in response to generating the second error-detecting code value, determining whether the second error-detecting code value is the same value as the error-detecting code value by comparing the second error-detecting code value with the error-detecting code value; and

in response to determining that the second error-detecting code value is the same value as the error-detecting code value, servicing, by the component, the request.

2. The method of claim 1, wherein generating the second error-detecting code value using the request and the signature comprises:

determining a secret value for the device using an identifier for the device;

generating a hash value using the physical address and the secret value; and

generating the signature using at least a portion of the hash value.

3. The method of claim 1, wherein servicing the request comprises forwarding the request to a second component.

4. The method of claim 3, comprising updating settings data in the request to indicate that the request does not include a checksum prior to forwarding the request to the second component.

5. The method of claim 3, comprising:

receiving, from the second component, a response; and

providing, to the device, at least a portion of the response.

6. The method of claim 1, wherein generating, by the component, the signature for the physical address in response to receiving the request comprises:

in response to receiving the request, determining whether the request includes a virtual address; and

generating the signature for the physical address using the physical address is responsive to determining that the request does not include a virtual address.

7. The method of claim 1, wherein receiving, by the component from the device, the request comprises receiving, by a memory management unit from a device connected to a motherboard that includes the memory management unit, the request.

8. The method of claim 7, wherein receiving, by the memory management unit from the device, the request comprises receiving, by the memory management unit from a peripheral device connected to the motherboard that includes the memory management unit, the request.

9. A system comprising a data processing apparatus, and a non-transitory computer readable storage medium in data communication with the data processing apparatus and storing instructions executable by the data processing apparatus and upon such execution cause the data processing apparatus to perform operations comprising:

receiving, from a device, a request that includes a physical address and an error-detecting code value and that requests access to a memory location identified by the physical address;

in response to receiving the request, generating a signature for the physical address using the physical address, wherein the request does not include the signature and the error-detecting code value was previously generated using the signature;

in response to generating the signature, generating a second error-detecting code value using the request and the signature;

in response to generating the second error-detecting code value, determining whether the second error-detecting code value is the same value as the error-detecting code value by comparing the second error-detecting code value with the error-detecting code value; and

in response to determining that the second error-detecting code value is the same value as the error-detecting code value, servicing the request.

10. The system of claim 9, wherein generating the second error-detecting code value using the request and the signature comprises:

determining a secret value for the device using an identifier for the device;

generating a hash value using the physical address and the secret value; and

generating the signature using at least a portion of the hash value.

11. The system of claim 9, wherein servicing the request comprises forwarding the request to a component.

12. The system of claim 11, the operations comprising updating settings data in the request to indicate that the request does not include a checksum prior to forwarding the request to the component.

13. The system of claim 11, the operations comprising:

receiving, from the component, a response; and

providing, to the device, at least a portion of the response.

14. The system of claim 9, wherein generating the signature for the physical address in response to receiving the request comprises:

in response to receiving the request, determining whether the request includes a virtual address; and

generating the signature for the physical address using the physical address is responsive to determining that the request does not include a virtual address.

15. The system of claim 9, wherein:

the data processing apparatus comprises a memory management unit; and

receiving, from the device, the request comprises receiving, from a device connected to a motherboard that includes the memory management unit, the request.

16. The system of claim 15, wherein receiving, from the device, the request comprises receiving, from a peripheral device connected to the motherboard that includes the memory management unit, the request.

17. A non-transitory computer readable storage medium storing instructions executable by a data processing apparatus and upon such execution cause the data processing apparatus to perform operations comprising:

receiving, from a device, a request that includes a physical address, an error-detecting code value, and settings data that indicates that the request does not include a checksum and that requests access to a memory location identified by the physical address;

in response to receiving the request, determining a signature for the physical address wherein the request does not include the signature and the error-detecting code value was previously generated using the signature;

in response to determining the signature, generating a second error-detecting code value using the request and the signature;

in response to generating the second error-detecting code value, determining whether the second error-detecting code value is the same value as the error-detecting code value by comparing the second error-detecting code value with the error-detecting code value; and

in response to determining that the second error-detecting code value is the same value as the error-detecting code value, servicing the request.

18. The computer readable storage medium of claim 17, wherein generating the second error-detecting code value using the request and the signature comprises:

determining a secret value for the device using an identifier for the device;

generating a hash value using the physical address and the secret value; and

generating the signature using at least a portion of the hash value.

19. The computer readable storage medium of claim 17, wherein servicing the request comprises forwarding the request to a component.

20. The computer readable storage medium of claim 19, the operations comprising:

receiving, from the component, a response; and

providing, to the device, at least a portion of the response.

21. The computer readable storage medium of claim 17, wherein determining the signature for the physical address in response to receiving the request comprises:

in response to receiving the request, determining whether the request includes a virtual address; and

generating the signature for the physical address using the physical address is responsive to determining that the request does not include a virtual address.

22. The computer readable storage medium of claim 17, wherein:

the data processing apparatus comprises a memory management unit; and

receiving, from the device, the request comprises receiving, from a device connected to a motherboard that includes the memory management unit, the request.

23. The computer readable storage medium of claim 22, wherein receiving, from the device, the request comprises receiving, from a peripheral device connected to the motherboard that includes the memory management unit, the request.