Patent Grant
7137016
Embodiments of the invention relate to power management of a data processing system, and more specifically, to dynamically loading power management code in a secure environment of a data processing system.
In many modern communication systems, including computer networks, the reliability and security of the information being exchanged is a significant concern. For example, in the Trusted Computing Platform Alliance (TCPA) model, each computer has a trusted hardware device called a Trusted Platform Module (TPM). TPM may record information about the software and hardware environment of the computer, with each TPM having a unique endorsement key (EK). A certificate, containing information about the TPM and platform, may be issued to the owner of the EK.
Accordingly, application software having a trusted EK may communicate with other applications within the system. However, power management features have not been addressed by the currently available techniques. Currently, the power management code, such as advanced configuration power interface (ACPI) code, cannot be loaded or unloaded dynamically in a secure environment as a trusted module.
The invention may best be understood by referring to the following description and accompanying drawings that are used to illustrate embodiments of the invention. In the drawings:
Methods and apparatuses for dynamically loading and unloading power management code, such as ACPI source language (ASL) code, during launch of a secure operating environment are described herein. According to one embodiment, this allows for execution of ACPI ASL control methods within the secure environment. When the secure environment is not needed, the power management code may be dynamically unloaded prior to termination of the secure environment.
According to one embodiment, prior to loading the ACPI definition block, an authentication sequence is performed by a trusted secure environment using a public-private key pair. The authentication ensures that the runtime ASL code executed is always trusted (e.g., authenticated). As a result, a critical ACPI definition block is kept secure from other untrusted entities.
In the following description, numerous specific details are set forth. However, it is understood that embodiments of the invention may be practiced without these specific details. In other instances, well-known circuits, structures and techniques have not been shown in detail in order not to obscure the understanding of this description.
Some portions of the detailed descriptions which follow are presented in terms of algorithms and symbolic representations of operations on data bits within a computer memory. These algorithmic descriptions and representations are used by those skilled in the data processing arts to most effectively convey the substance of their work to others skilled in the art. An algorithm is here, and generally, conceived to be a self-consistent sequence of operations leading to a desired result. The operations are those requiring physical manipulations of physical quantities. Usually, though not necessarily, these quantities take the form of electrical or magnetic signals capable of being stored, transferred, combined, compared, and otherwise manipulated. It has proven convenient at times, principally for reasons of common usage, to refer to these signals as bits, values, elements, symbols, characters, terms, numbers, or the like.
It should be borne in mind, however, that all of these and similar terms are to be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities. Unless specifically stated otherwise as apparent from the following discussion, it is appreciated that throughout the description, discussions utilizing terms such as “processing” or “computing” or “calculating” or “determining” or “displaying” or the like, refer to the action and processes of a computer system, or similar data processing device, that manipulates and transforms data represented as physical (e.g. electronic) quantities within the computer system's registers and memories into other data similarly represented as physical quantities within the computer system memories or registers or other such information storage, transmission or display devices.
Embodiments of the present invention also relate to apparatuses for performing the operations described herein. An apparatus may be specially constructed for the required purposes, or it may comprise a general purpose computer selectively activated or reconfigured by a computer program stored in the computer. Such a computer program may be stored in a computer readable storage medium, such as, but is not limited to, any type of disk including floppy disks, optical disks, CD-ROMs, and magnetic-optical disks, read-only memories (ROMs), random access memories (RAMs) such as Dynamic RAM (DRAM), erasable programmable ROMs (EPROMs), electrically erasable programmable ROMs (EEPROMs), magnetic or optical cards, or any type of media suitable for storing electronic instructions, and each of the above storage components is coupled to a computer system bus.
The algorithms and displays presented herein are not inherently related to any particular computer or other apparatus. Various general purpose systems may be used with programs in accordance with the teachings herein, or it may prove convenient to construct more specialized apparatus to perform the methods. The structure for a variety of these systems will appear from the description below. In addition, embodiments of the present invention are not described with reference to any particular programming language. It will be appreciated that a variety of programming languages may be used to implement the teachings of the embodiments of the invention as described herein.
A machine-readable medium includes any mechanism for storing or transmitting information in a form readable by a machine (e.g., a computer). For example, a machine-readable medium includes read only memory (“ROM”); random access memory (“RAM”); magnetic disk storage media; optical storage media; flash memory devices; electrical, optical, acoustical or other form of propagated signals (e.g., carrier waves, infrared signals, digital signals, etc.); etc.
Note that while
As shown in
According to one embodiment, an operating system (OS) may be launched and executed by processor 103 in a memory, such as volatile RAM 105. The exemplary operating system may be a Windows OS from Microsoft of Redmond, Wash. Alternatively, the operating system may be a Mac OS from Apple Computer of Cupertino, Calif. Other operating systems, such as UNIX, LINUX, or other real time embedded OSs may be utilized. The operating system may include one or more virtual machines (VMs) similar to those shown in
In a particular embodiment, the OS may detect a secure transaction initiated by a user, such as an application handling online secure transaction with a third party over a network and launches a secure environment, such as, for example, a specific VM (also referred to as a secure or protected VM), to handle the related applications used to complete the transaction. The OS may further include a power management loader during the launching of the secure environment (e.g., the specific VM), such as an ACPI loader, to dynamically load the power management code, such as ACPI code, into a dedicated memory, which may be dedicated or reserved by the OS or hardware, such as chip set 103 of system 100. Prior to loading the power management code, according to one embodiment, the loader performs one or more authentication processes to prove that the power management code is trusted. The authentication processes may be similar to those shown in
After the user completes the related secure transactions, the secure environment, such as corresponding secure VM may be terminated. Prior to the termination of the VM, according to one embodiment, the respective loaded power management code may be dynamically unloaded. As a result, the power management code is only loaded and executed within a secure environment having trusted parties, without unnecessarily exposing itself to an untrusted party, contrary to a conventional approach.
A single physical device (e.g., exemplary system 100 of
It will be appreciated that VMs may communicate with other VMs within the same physical device, with VMs on other physical devices, or simply with other physical devices. In one embodiment, multiple VMs hosted on a particular physical device may communicate among themselves on a private, virtual (optimized) network. In this latter case, the virtualization software (often the VMM or the host operating system, depending on implementation) may operate in a different manner, e.g. allowing inter-VM communication more efficiently through a virtual local network not externally visible outside of the hosting device.
Referring to
The term “hook” or “hooks” refers to mechanisms such as passive or active interfaces (e.g. polled API's, memory locations, or subroutine call-backs), notifications, messages, interrupts, and their associated handlers etc. Each of these provides different tradeoffs, which are important to overall system design, but may be incorporated by one skilled in the art. For example, when a VMM terminates a VM, it may notify the registry agent to remove or mark as unavailable all service entries associated with that VM. Often this might be the IP address or hostname of the VM.
According to one embodiment, VMs 206–210 operate in conjunction with a VMM 218. The VMM operates above device hardware 220 and regulates/arbitrates access by the VMs to the physical device hardware. In one embodiment, the VMM also regulates VM access to host operating system 202 resources. The VMM may be configured to allow complete isolation of VMs 206–210 (e.g., secure vs. unsecure VMs), or to allow data sharing between some or all of the VMs according to desired security policies. It will be appreciated that the VMM may be implemented in various ways, including in software, hardware, or a combination thereof on a host. For example, the VMM may be implemented as an application and device drivers (including power management functionality), etc. (e.g. VMWare by VMware, Inc. of California), as part of the operating system 202, or as part of a chipset or a microprocessor, such as processor 103 of the exemplary system 100 shown in
According to one embodiment, VMM 218 is configured to monitor the state of VMs and to automatically issue notifications to a registry to cause the registration and de-registration of VM services 212–216 based on monitored state. In one embodiment, the VMM 218 monitors at least VM creation, destruction, suspension requests, as well as registry advertising/de-registration requests to identify VMs having registry registrations affected by a change in VM status. In one embodiment, operating system hooks 222 are used to monitor operating system calls relating to advertising/de-registration requests and to implement registry registration changes. The operating system 202 and registry 204 are presumed responsive to notification by the VMM to register or de-register services.
According to one embodiment, one of the VMs 206–210 may be implemented or launched as a secure VM (e.g., secure environment) in response to a secure transaction initiated by a user. For example, certain services or applications, such as services 212–216, have been certified as trusted services or applications prior to being released to a customer or distributor. When such services or applications are launched, certain communications with the system (e.g., OS 202) happen indicating that a secure operating environment is needed. As a result, prior to launching the respective application or service, a secure VM will be launched, within which the desired service or application may be launched thereafter. Other mechanisms, such as application employing strong encryption algorithms may be used to determine whether a secure environment is needed. Accordingly, the respective VM may be launched or loaded in into a dedicated memory and its services offered are launched if they are determined as trusted parties (e.g., successfully authenticated). During the launching of the secure VM, a trusted version of power management code, such as ACPI code is authenticated and loaded within the VM to handle any power management issues within the secure environment. Once the user completes the transaction, the ACPI code may be dynamically unloaded and the respective VM may be terminated thereafter.
In this embodiment, hooks between the VMM 326 and various VM operating systems 318–324 (or service modules 310–316) allow the VMM to monitor registrations of the VMs 302–308 offered and/or desired services 310–316. Some of the VMs 304–308 may be launched as a secure VM including a trusted power management code, such as trusted ACPI code.
According to one embodiment, while launching the secure environment associated with VM 402, power management code, such as ACPI code 408, is authenticated and loaded within VM 402. ACPI code 408 may be provided by a trusted vendor, which may be certified by a trusted community, such as TCPA alliance. Once the user has completed the transaction via applications 406, ACPI code 408 may be unloaded dynamically and the secure environment (e.g., VM 402) may be terminated thereafter. VM 402 may be managed by secured VM monitor (SVMM) 403. According to one embodiment, SVMM 403 provides domain separation, VM entry/exit policy enforcement, and inter-VM communications channels, such as communications between secure VM 402 and other VMs 401 having respective untrusted applications 404 and corresponding OS portion 405. According to one embodiment, the trusted kernel 407 provides intra-VM services and it may be designed to interact with a specific main OS, such as OS 405. Note that in one embodiment, protected VM 402 and SVMM 403 are loaded in a dedicated memory 409, which is reserved, by hardware or software, or the both for secure environments.
Both secure VM 402 and VM 401 may exist within a single host, such as system 300 of
Referring to
If the power management code is determined to be trusted (e.g., it has been successfully authenticated), at block 503, processing logic loads the power management code dynamically into a dedicated memory, which may be protected by the software or hardware, or the both for the purposes of the secure environments. Once the power management code is successfully loaded, at block 504, processing logic continues to complete launching the secure environment. Once the secure environment has been launched, at block 505, the user may perform a secure transaction via one or more trusted applications (e.g., applications 406 of
However, if it is determined that the power management code is not trusted (e.g., it has not been successfully authenticated), at block 507, processing logic may issue one or more errors. Alternatively, processing logic may issue one or more warnings and continue to load the power management code as untrusted version and the warning message may be issued to the user to indicate that one or more components of the secure environment is not trusted. Other operations may be included.
In one embodiment, exemplary power management code 601 is an ACPI compatible code, which may include, among others, a header 602, a public key 603, a signature block 604, a ACM (ACPI code module) body 606, and some other scratch spaces 605. ACPI code 601 may be stored in a ROM, such as ROM 107 of data processing system 100 shown in
Referring to
If the public key hash in the hardware matches the computed hash of the public key in the module, according to one embodiment, processing logic reads the header 602 and the ACM body 606 from the ACPI code 601 to generate a first computed module hash result 609, via a hash operation, such as SHA-1 or MD-5 hash function. Thereafter, processing logic reads the signature block 604 from ACPI code 601 and performs a decryption on signature block 604. In one embodiment, signature block 604 may be decrypted using a public key via a variety of decryption algorithms, such as an RSA decryption algorithm from RSA Security, Inc., to generate a second module hash result 610. The first and second module hash results 609 and 610 are compared, via operation 611, to determine whether they are matched. If they are matched, the ACPI code 601 has been successfully authenticated.
Referring to
If the public key hash stored in the hardware matches the computed hash of the public key in the module, at block 703, processing logic performs another hash operation via a hash function (e.g., SHA-1 or MD-5 hash function) on at least a portion of the power management code, such as header 602 of ACPI code 601 shown in
Thus, methods and apparatuses for dynamically loading and unloading power management code in a secure environment have been described. In the foregoing specification, the invention has been described with reference to specific exemplary embodiments thereof. It will be evident that various modifications may be made thereto without departing from the broader spirit and scope of the invention as set forth in the following claims. The specification and drawings are, accordingly, to be regarded in an illustrative sense rather than a restrictive sense.
| Number | Name | Date | Kind |
|---|---|---|---|
| 6122745 | Wong-Insley | Sep 2000 | A |
| 6957332 | Ellison et al. | Oct 2005 | B1 |
| 20030229802 | Challener et al. | Dec 2003 | A1 |
| Number | Date | Country | |
|---|---|---|---|
| 20050055588 A1 | Mar 2005 | US |
