Authenticated Debug for Computing Systems

Patent metadata

Field	Value
Publication number	US-2022027519-A1
Application number	US-202016936150-A
Country	US
Kind code	A1
Filing date	Jul 22, 2020
Priority date	Jul 22, 2020
Publication date	Jan 27, 2022
Grant date	—

Abstract

An apparatus includes one or more functional circuits, a debug circuit configured to implement one or more debug features for the one or more functional circuits, and a validation circuit. The validation circuit is configured to receive a request to access debug features, and to send an identification value corresponding to the apparatus. The validation circuit is further configured to receive a certificate generated by a server computer system, the certificate including encoded debug permissions, and to decode the debug permissions using the identification value. Using the decoded debug permissions, the validation circuit is further configured to enable one or more of the debug features.

First claim

What is claimed is:

1 . An apparatus, comprising:
one or more functional circuits; a debug circuit configured to implement one or more debug features for the one or more functional circuits; and a validation circuit configured to:
receive a request to access debug features;
send an identification value corresponding to the apparatus;
receive a certificate generated by a server computer system, the certificate including encoded debug permissions;
decode the encoded debug permissions using the identification value; and
using the decoded debug permissions, enable one or more of the debug features.

2 . The apparatus of claim 1 , wherein the validation circuit is further configured to:
in response to receiving the request, generate a liveness token, wherein the liveness token includes a one-time use value; and send the generated liveness token with the identification value.

3 . The apparatus of claim 2 , wherein the validation circuit is further configured, in response to receiving the certificate, to:
compare a received liveness token extracted from the certificate to the generated liveness token; and based on the comparison, selectively permit the debug circuit to be accessed.

4 . The apparatus of claim 1 , wherein the validation circuit is further configured to send information indicative of available features of the debug circuit and currently enabled features of the debug circuit.

5 . The apparatus of claim 1 , wherein the validation circuit is further configured, in response to receiving the certificate, to determine if the reception of the certificate is expected.

6 . The apparatus of claim 1 , wherein the validation circuit is further configured to end an active debug session in response to a determination that a particular amount of time has elapsed since receiving the certificate, wherein the particular amount of time is indicated in the certificate.

7 . The apparatus of claim 1 , wherein the validation circuit is further configured to end an active debug session in response to a determination that a number of allowed device resets, as indicated by the certificate, have occurred.

8 . The apparatus of claim 1 , wherein the validation circuit receives the request from a first computing device, and wherein the validation circuit is further configured to end an active debug session in response to a determination that a second computing device has been connected to the apparatus.

9 . The apparatus of claim 1 , wherein the validation circuit is further configured to authenticate a digital signature that is included in the received certificate.

10 . A non-transitory computer-readable medium having instructions stored thereon that are executable by a computer system to perform operations comprising:
sending, to a device, a request to access debug features of the device; in response to receiving an identification value from the device, sending, to a server computer system, a certificate request to access the debug features of the device, the certificate request including the identification value; receiving a certificate from the server computer system, the certificate including debug permissions; sending the certificate to the device; and accessing one or more of the debug features of the device based on the debug permissions in the certificate.

11 . The non-transitory computer-readable medium of claim 10 , wherein the operations further comprise:
requesting, from the device, a liveness token that includes a one-time use value; and including the liveness token in the certificate request.

12 . The non-transitory computer-readable medium of claim 10 , wherein the operations further comprise including authentication credentials for a user of the computer system in the certificate request.

13 . The non-transitory computer-readable medium of claim 10 , wherein the operations further comprise:
requesting, from the device, a first value indicating a plurality of debug features available on the device, and a second value indicating a subset of the plurality of debug features that are currently locked; using the first value and the second value to generate a third value indicating one or more of the plurality of debug features to be accessed; and including the third value in the certificate request.

14 . The non-transitory computer-readable medium of claim 10 , wherein the operations further comprise sending, to the device, a command to end a current debug session.

15 . The non-transitory computer-readable medium of claim 10 , wherein the operations further comprise including, in the certificate request, a user-specified number of device resets that are allowed by the device while maintaining a validity of the certificate.

16 . A method, comprising:
maintaining, by a server computer system, one or more policies that indicate debug permissions for one or more users to access debug features of one or more devices; receiving, by the server computer system from a debug system, a request to access debug features of a particular device, the request including an identification value associated with the particular device; validating, by the server computer system using the identification value, the request; in response to the validating, determining, by the server computer system, debug permissions for a particular user based on the one or more policies; and sending, by the server computer system, a certificate to the debug system, the certificate indicating the debug permissions.

17 . The method of claim 16 , wherein the validating includes:
receiving authentication credentials for the particular user; and in response to a successful validation of the authentication credentials, identifying a particular policy that corresponds to the particular user.

18 . The method of claim 17 , wherein the validating, using the identification value, includes determining if the particular policy is valid for the particular device or for a class of devices that includes the particular device.

19 . The method of claim 17 , wherein determining the debug permissions for the particular user includes:
receiving, from the request, a first value indicating one or more debug features to be accessed; and generating, using the particular policy, a second value indicating at least one of the one or more debug features for which access is granted.

20 . The method of claim 16 , wherein validating the request comprises determining a geographic location of the debug system.

Assignees

• Apple Inc

Inventors

• Kataria Mukesh
• Hauck Jerrold V

Classifications

• G06F11/3698

  Environments for analysis, debugging or testing of software · CPC title

• G06F21/73

  by creating or determining hardware identification, e.g. serial numbers · CPC title

• G06F21/629

  to features or functions of an application · CPC title

• H04L63/0838

  using one-time-passwords · CPC title

• H04L63/0823

  using certificates (cryptographic mechanisms or cryptographic arrangements for entity authentication involving certificates H04L9/3263) · CPC title