Method and Apparatus for On-Demand Isolated I/O Channels for Secure Applications

• US 20170177854A1
• Filed: 05/15/2015
• Published: 06/22/2017
• Est. Priority Date: 05/15/2014
• Status: Active Grant

• Current Assignee: Carnegie Mellon University
• Original Assignee: Carnegie Mellon University
• Inventors: Gligor, Virgil D, Zhou, Zongwei, Yu, Miao
• Granted Patent: US 10,235,515 B2
• Time in Patent Office: Days
• CPC Class Codes: G06F 2009/45579 I/O management, e.g. providing access to device drivers or storage
• CPC Class Codes: G06F 2009/45587 Isolation or security of virtual machine instances
• CPC Class Codes: G06F 21/44 Program or device authentication
• CPC Class Codes: G06F 21/53 by executing in a restricted environment, e.g. sandbox or secure virtual machine
• CPC Class Codes: G06F 21/57 Certifying or maintaining trusted computer platforms, e.g. secure boots or power-downs, version controls, system software checks, secure updates or assessing vulnerabilities
• CPC Class Codes: G06F 21/572 Secure firmware programming, e.g. of basic input output system [BIOS]
• CPC Class Codes: G06F 2221/034 Test or assess a computer or a system
• CPC Class Codes: G06F 2221/2141 Access rights, e.g. capability lists, access control lists, access tables, access matrices
• CPC Class Codes: G06F 2221/2145 Inheriting rights or properties, e.g., propagation of permissions or restrictions within a hierarchy
• CPC Class Codes: G06F 9/45558 Hypervisor-specific management and integration aspects

Abstract

A computing platform for on-demand I/O channels, which enable secure application to dynamically connect to diverse peripheral devices of untrusted commodity OSes

Claims

1. A system for providing input/output channels to a secure application, comprising:

one or more processors;

one or more input/output (I/O) devices, said devices in communication with at least one of said processors; and

memory, connected to said one or more processors and including computer-readable instructions which, when executed by one of said processors, cause the processor to create a computing platform having;

one or more untrusted operating systems;

a trusted computing base;

a trusted I/O kernel; and

a communications channel between said untrusted operating system and said trusted I/O kernel.

2. The system of claim 1 wherein one or more secure applications may be run on top of said trusted input/output kernel.

3. The system of claim 2 wherein said trusted computing base creates one or more isolated domains, each of said isolated domains comprising:

processor contents; and

one or more regions of memory, said regions of memory being for the exclusive use of said isolated domain.

4. The system of claim 3 wherein said trusted computing base partitions memory into a plurality of portions comprising:

a portion for the exclusive use of said trusted computing base;

a portion for the exclusive use of said trusted input/output kernel and one or more secure applications; and

a portion for the exclusive use of said one or more untrusted operating systems and one or more untrusted applications.

5. The system of claim 4 wherein said trusted I/O kernel runs in a first isolated domain.

6. The system of claim 5 wherein said secure application runs in a second isolated domain.

7. The system of claim 4 wherein said trusted I/O kernel and said secure application run in the same isolated domain

8. The system of claim 5 wherein each of said one or more secure applications includes one or more device drivers and further wherein each of said one or more secured application has exclusive use of an I/O device associated with said device driver.

9. The system of claim 8 wherein said trusted kernel decomposes said device drivers and exports portions of said device drivers to said secure applications for execution.

10. The system of claim 8 wherein input/output devices are reserved for exclusive and verified use by said secured application when:

said untrusted operating system configures an I/O device for use by a secure application and releases said device to said trusted I/O kernel;

said trusted I/O kernel verifies the configuration of the I/O device and assigns the I/O device to said secure application; and

said trusted I/O kernel provides channel isolation between said secure application and said I/O device.

11. The system of claim 9 wherein data transferred between said secure application and said I/O device cannot be intercepted or altered by said untrusted operating system, by other secure applications or by other I/O devices.

12. The system of claim 10 wherein said trusted I/O kernel provides isolation of interrupts generated by I/O devices assigned to a secure application.

13. The system of claim 3 wherein said trusted computing base performs the functions of:

creating an isolated domain;

mapping a secure application to said isolated domain;

mapping I/O device resources required by said secure application to said isolated domain; and

transferring control to said trusted I/O kernel

14. The system of claim 1 further comprising a plug-in to said untrusted operating system, said plug-in performing the functions of configuring I/O devices for use by the trusted I/O kernel and releasing control of said I/O devices to said trusted I/O kernel.

15. The system of claim 1 wherein said trusted computing base runs at the highest privilege level of said computing platform.

16. The system of claim 3 wherein said trusted computing base relies on a trusted platform module to implement a security primitive.

17. The system of claim 16 wherein said trusted computing base employs a plurality of security primitives, including:

controlling which of said isolated domains can access which memory regions;

controlling which device can perform direct memory access operations to the memory of aid isolated domain; and

performing sealed storage and attestation root-of-trust

18. The system of claim 17 wherein said sealed storage allows the biding of data with the identity of one or more isolated domains.

19. The system of claim 17 where said attestation root-or-trust allows the measurement of the identity of an isolated domain and the reporting of the measured identity to a third party for verification.