U.S. patent application number 17/152314 was filed with the patent office on 2022-07-21 for binding customer-signed image to a specific platform.
This patent application is currently assigned to Dell Products L.P.. The applicant listed for this patent is Dell Products L.P.. Invention is credited to Elie JREIJ, Balaji Bapu Gururaja RAO, Marshal SAVAGE, Paul VANCIL.
Application Number | 20220229911 17/152314 |
Document ID | / |
Family ID | |
Filed Date | 2022-07-21 |
United States Patent
Application |
20220229911 |
Kind Code |
A1 |
RAO; Balaji Bapu Gururaja ;
et al. |
July 21, 2022 |
BINDING CUSTOMER-SIGNED IMAGE TO A SPECIFIC PLATFORM
Abstract
An information handling system may include a circuit board; a
processor disposed on the circuit board, wherein the processor
includes a media access control (MAC) address and a hidden root key
(HRK) encoded therein; and a memory not disposed on the circuit
board. The information handling system may be configured to:
determine a customer public key (CPK); create a data structure
comprising the CPK and the MAC address; encrypt the data structure
using the HRK to generate an encrypted structure; and store the
encrypted structure in the memory.
Inventors: |
RAO; Balaji Bapu Gururaja;
(Austin, TX) ; JREIJ; Elie; (Pflugerville, TX)
; VANCIL; Paul; (Austin, TX) ; SAVAGE;
Marshal; (Austin, TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Dell Products L.P. |
Round Rock |
TX |
US |
|
|
Assignee: |
Dell Products L.P.
Round Rock
TX
|
Appl. No.: |
17/152314 |
Filed: |
January 19, 2021 |
International
Class: |
G06F 21/57 20060101
G06F021/57; G06F 13/42 20060101 G06F013/42; G06F 15/78 20060101
G06F015/78 |
Claims
1. An information handling system comprising: a circuit board; a
processor disposed on the circuit board, wherein the processor
includes a media access control (MAC) address and a hidden root key
(HRK) encoded therein; and a memory not disposed on the circuit
board; wherein the information handling system is configured to:
determine a customer public key (CPK); create a data structure
comprising the CPK and the MAC address; encrypt the data structure
using the HRK to generate an encrypted structure; and store the
encrypted structure in the memory.
2. The information handling system of claim 1, wherein the
information handling system comprises a management controller.
3. The information handling system of claim 2, wherein the
management controller is configured to carry out the determining,
the creating, the encrypting, and the storing.
4. The information handling system of claim 1, wherein the memory
is an integral part of a chassis of the information handling
system.
5. The information handling system of claim 1, wherein the memory
is a front-panel flash memory.
6. The information handling system of claim 5, wherein the
front-panel flash memory is coupled to the processor via a serial
peripheral interface (SPI) bus.
7. The information handling system of claim 1, wherein the data
structure further comprises an initialization vector (IV), and
wherein the information handling system is further configured to
store the IV in the memory.
8. The information handling system of claim 1, wherein, during a
subsequent boot process, the information handling system is further
configured to: read the encrypted structure from the memory;
decrypt the encrypted structure with the HRK to determine a
potential MAC address and a potential CPK; perform a first
comparison between the potential MAC address and the MAC address;
perform a second comparison between the potential CPK and the CPK;
and in response to a mismatch in either the first comparison or the
second comparison, disable execution of a customer-signed firmware
image.
9. A method executed in an information handling system including a
circuit board; a processor disposed on the circuit board, wherein
the processor includes a media access control (MAC) address and a
hidden root key (HRK) encoded therein; and a memory not disposed on
the circuit board, the method comprising: determining a customer
public key (CPK); creating a data structure comprising the CPK and
the MAC address; encrypting the data structure using the HRK to
generate an encrypted structure; and storing the encrypted
structure in the memory.
10. The method of claim 9, wherein the CPK is encoded into a vendor
boot loader of the information handling system.
11. The method of claim 9, wherein the processor is a
system-on-chip (SoC) of a management controller.
12. The method of claim 9, wherein the method is performed in
response to an instruction to enable execution of a customer-signed
firmware image.
13. An article of manufacture comprising a non-transitory,
computer-readable medium having computer-executable instructions
thereon that are executable by a processor of an information
handling system that includes a circuit board; a processor disposed
on the circuit board, wherein the processor includes a media access
control (MAC) address and a hidden root key (HRK) encoded therein;
and a memory not disposed on the circuit board, the instructions
executable for: determining a customer public key (CPK); creating a
data structure comprising the CPK and the MAC address; encrypting
the data structure using the HRK to generate an encrypted
structure; and storing the encrypted structure in the memory.
14. The article of claim 13, wherein the information handling
system comprises a management controller.
15. The article of claim 14, wherein the management controller is
configured to carry out the determining, the creating, the
encrypting, and the storing.
16. The article of claim 13, wherein the memory is an integral part
of a chassis of the information handling system.
17. The article of claim 13, wherein the memory is a front-panel
flash memory.
18. The article of claim 17, wherein the front-panel flash memory
is coupled to the processor via a serial peripheral interface (SPI)
bus.
19. The article of claim 13, wherein the data structure further
comprises an initialization vector (IV), and wherein the
information handling system is further configured to store the IV
in the memory.
20. The article of claim 19, wherein the instructions are further
executable for, during a subsequent boot process: reading the
encrypted structure from the memory; decrypting the encrypted
structure with the HRK to determine a potential MAC address and a
potential CPK; performing a first comparison between the potential
MAC address and the MAC address; performing a second comparison
between the potential CPK and the CPK; and in response to a
mismatch in either the first comparison or the second comparison,
disabling execution of a customer-signed firmware image.
Description
TECHNICAL FIELD
[0001] The present disclosure relates in general to information
handling systems, and more particularly to firmware images for
management controllers of information handling systems.
BACKGROUND
[0002] As the value and use of information continues to increase,
individuals and businesses seek additional ways to process and
store information. One option available to users is information
handling systems. An information handling system generally
processes, compiles, stores, and/or communicates information or
data for business, personal, or other purposes thereby allowing
users to take advantage of the value of the information. Because
technology and information handling needs and requirements vary
between different users or applications, information handling
systems may also vary regarding what information is handled, how
the information is handled, how much information is processed,
stored, or communicated, and how quickly and efficiently the
information may be processed, stored, or communicated. The
variations in information handling systems allow for information
handling systems to be general or configured for a specific user or
specific use such as financial transaction processing, airline
reservations, enterprise data storage, or global communications. In
addition, information handling systems may include a variety of
hardware and software components that may be configured to process,
store, and communicate information and may include one or more
computer systems, data storage systems, and networking systems.
[0003] As discussed in more detail below, an information handling
system may include a management controller such as a baseboard
management controller (BMC). Typically the firmware image for such
a management controller is provided and signed by the
manufacturer/distributor/vendor of the information handling system.
But in some instances, a customer may desire the ability to build
and cryptographically sign their own BMC image (e.g., based on an
open source project such as OpenBMC).
[0004] But the ability for a customer to do so may defeat the
assurances provided by immutable root-of-trust implementations
(also referred to as silicon-based root-of-trust), where only the
vendor can sign and release BMC code.
[0005] It may be possible to enable customer signing and attempt to
limit the signing to specific information handling systems by using
a controlled method to store the customer's public key into a
vendor-signed boot loader (e.g., uboot). Then the vendor-signed
uboot may accept and chain load the customer-signed BMC images that
are signed with the customer private key.
[0006] However, such a solution may not protect from the ability to
move the customer-signed capability to another information handling
system chassis, which might happen if the motherboard is
maliciously moved to another chassis, or if the motherboard is
returned for repair, put into service stock, and later sent out to
replace a broken motherboard, or in other situations.
[0007] Embodiments of this disclosure may provide techniques to
prevent a customer-signed firmware from being used in a different
information handling system.
[0008] It should be noted that for purposes of this disclosure, the
term "vendor" will be used to refer to any party such as the
manufacturer, distributor, or vendor of an information handling
system. Further, the term "BMC" may be used broadly to refer to any
type of management controller. Further, the term "uboot" may be
used broadly to refer to any type of boot loader.
[0009] It should be noted that the discussion of a technique in the
Background section of this disclosure does not constitute an
admission of prior-art status. No such admissions are made herein,
unless clearly and unambiguously identified as such.
SUMMARY
[0010] In accordance with the teachings of the present disclosure,
the disadvantages and problems associated with firmware images of
management controllers of information handling systems may be
reduced or eliminated.
[0011] In accordance with embodiments of the present disclosure, an
information handling system may include a circuit board; a
processor disposed on the circuit board, wherein the processor
includes a media access control (MAC) address and a hidden root key
(HRK) encoded therein; and a memory not disposed on the circuit
board. The information handling system may be configured to:
determine a customer public key (CPK); create a data structure
comprising the CPK and the MAC address; encrypt the data structure
using the HRK to generate an encrypted structure; and store the
encrypted structure in the memory.
[0012] In accordance with these and other embodiments of the
present disclosure, a method may be executed in an information
handling system including a circuit board; a processor disposed on
the circuit board, wherein the processor includes a media access
control (MAC) address and a hidden root key (HRK) encoded therein;
and a memory not disposed on the circuit board. The method may
include: determining a customer public key (CPK); creating a data
structure comprising the CPK and the MAC address; encrypting the
data structure using the HRK to generate an encrypted structure;
and storing the encrypted structure in the memory.
[0013] In accordance with these and other embodiments of the
present disclosure, an article of manufacture may include a
non-transitory, computer-readable medium having computer-executable
instructions thereon that are executable by a processor of an
information handling system that includes a circuit board; a
processor disposed on the circuit board, wherein the processor
includes a media access control (MAC) address and a hidden root key
(HRK) encoded therein; and a memory not disposed on the circuit
board, the instructions executable for: determining a customer
public key (CPK); creating a data structure comprising the CPK and
the MAC address; encrypting the data structure using the HRK to
generate an encrypted structure; and storing the encrypted
structure in the memory.
[0014] Technical advantages of the present disclosure may be
readily apparent to one skilled in the art from the figures,
description and claims included herein. The objects and advantages
of the embodiments will be realized and achieved at least by the
elements, features, and combinations particularly pointed out in
the claims.
[0015] It is to be understood that both the foregoing general
description and the following detailed description are examples and
explanatory and are not restrictive of the claims set forth in this
disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] A more complete understanding of the present embodiments and
advantages thereof may be acquired by referring to the following
description taken in conjunction with the accompanying drawings, in
which like reference numbers indicate like features, and
wherein:
[0017] FIG. 1 illustrates a block diagram of an example information
handling system, in accordance with embodiments of the present
disclosure;
[0018] FIG. 2 illustrates a block diagram of an example method, in
accordance with embodiments of the present disclosure; and
[0019] FIG. 3 illustrates a block diagram of an example method, in
accordance with embodiments of the present disclosure.
DETAILED DESCRIPTION
[0020] Preferred embodiments and their advantages are best
understood by reference to FIGS. 1 through 3, wherein like numbers
are used to indicate like and corresponding parts.
[0021] For the purposes of this disclosure, the term "information
handling system" may include any instrumentality or aggregate of
instrumentalities operable to compute, classify, process, transmit,
receive, retrieve, originate, switch, store, display, manifest,
detect, record, reproduce, handle, or utilize any form of
information, intelligence, or data for business, scientific,
control, entertainment, or other purposes. For example, an
information handling system may be a personal computer, a personal
digital assistant (PDA), a consumer electronic device, a network
storage device, or any other suitable device and may vary in size,
shape, performance, functionality, and price. The information
handling system may include memory, one or more processing
resources such as a central processing unit ("CPU") or hardware or
software control logic. Additional components of the information
handling system may include one or more storage devices, one or
more communications ports for communicating with external devices
as well as various input/output ("I/O") devices, such as a
keyboard, a mouse, and a video display. The information handling
system may also include one or more buses operable to transmit
communication between the various hardware components.
[0022] For purposes of this disclosure, when two or more elements
are referred to as "coupled" to one another, such term indicates
that such two or more elements are in electronic communication or
mechanical communication, as applicable, whether connected directly
or indirectly, with or without intervening elements.
[0023] When two or more elements are referred to as "coupleable" to
one another, such term indicates that they are capable of being
coupled together.
[0024] For the purposes of this disclosure, the term
"computer-readable medium" (e.g., transitory or non-transitory
computer-readable medium) may include any instrumentality or
aggregation of instrumentalities that may retain data and/or
instructions for a period of time. Computer-readable media may
include, without limitation, storage media such as a direct access
storage device (e.g., a hard disk drive or floppy disk), a
sequential access storage device (e.g., a tape disk drive), compact
disk, CD-ROM, DVD, random access memory (RAM), read-only memory
(ROM), electrically erasable programmable read-only memory
(EEPROM), and/or flash memory; communications media such as wires,
optical fibers, microwaves, radio waves, and other electromagnetic
and/or optical carriers; and/or any combination of the
foregoing.
[0025] For the purposes of this disclosure, the term "information
handling resource" may broadly refer to any component system,
device, or apparatus of an information handling system, including
without limitation processors, service processors, basic
input/output systems, buses, memories, I/O devices and/or
interfaces, storage resources, network interfaces, motherboards,
and/or any other components and/or elements of an information
handling system.
[0026] For the purposes of this disclosure, the term "management
controller" may broadly refer to an information handling system
that provides management functionality (typically out-of-band
management functionality) to one or more other information handling
systems. In some embodiments, a management controller may be (or
may be an integral part of) a service processor, a baseboard
management controller (BMC), a chassis management controller (CMC),
or a remote access controller (e.g., a Dell Remote Access
Controller (DRAC) or Integrated Dell Remote Access Controller
(iDRAC)).
[0027] FIG. 1 illustrates a block diagram of an example information
handling system 102, in accordance with embodiments of the present
disclosure. In some embodiments, information handling system 102
may comprise a server chassis configured to house a plurality of
servers or "blades." In other embodiments, information handling
system 102 may comprise a personal computer (e.g., a desktop
computer, laptop computer, mobile computer, and/or notebook
computer). In yet other embodiments, information handling system
102 may comprise a storage enclosure configured to house a
plurality of physical disk drives and/or other computer-readable
media for storing data (which may generally be referred to as
"physical storage resources"). As shown in FIG. 1, information
handling system 102 may comprise a processor 103, a memory 104
communicatively coupled to processor 103, a BIOS 105 (e.g., a UEFI
BIOS) communicatively coupled to processor 103, a network interface
108 communicatively coupled to processor 103, and a management
controller 112 communicatively coupled to processor 103.
[0028] In operation, processor 103, memory 104, BIOS 105, and
network interface 108 may comprise at least a portion of a host
system 98 of information handling system 102. In addition to the
elements explicitly shown and described, information handling
system 102 may include one or more other information handling
resources.
[0029] Processor 103 may include any system, device, or apparatus
configured to interpret and/or execute program instructions and/or
process data, and may include, without limitation, a
microprocessor, microcontroller, digital signal processor (DSP),
application specific integrated circuit (ASIC), or any other
digital or analog circuitry configured to interpret and/or execute
program instructions and/or process data. In some embodiments,
processor 103 may interpret and/or execute program instructions
and/or process data stored in memory 104 and/or another component
of information handling system 102.
[0030] Memory 104 may be communicatively coupled to processor 103
and may include any system, device, or apparatus configured to
retain program instructions and/or data for a period of time (e.g.,
computer-readable media). Memory 104 may include RAM, EEPROM, a
PCMCIA card, flash memory, magnetic storage, opto-magnetic storage,
or any suitable selection and/or array of volatile or non-volatile
memory that retains data after power to information handling system
102 is turned off.
[0031] As shown in FIG. 1, memory 104 may have stored thereon an
operating system 106. Operating system 106 may comprise any program
of executable instructions (or aggregation of programs of
executable instructions) configured to manage and/or control the
allocation and usage of hardware resources such as memory,
processor time, disk space, and input and output devices, and
provide an interface between such hardware resources and
application programs hosted by operating system 106. In addition,
operating system 106 may include all or a portion of a network
stack for network communication via a network interface (e.g.,
network interface 108 for communication over a data network).
Although operating system 106 is shown in FIG. 1 as stored in
memory 104, in some embodiments operating system 106 may be stored
in storage media accessible to processor 103, and active portions
of operating system 106 may be transferred from such storage media
to memory 104 for execution by processor 103.
[0032] Network interface 108 may comprise one or more suitable
systems, apparatuses, or devices operable to serve as an interface
between information handling system 102 and one or more other
information handling systems via an in-band network. Network
interface 108 may enable information handling system 102 to
communicate using any suitable transmission protocol and/or
standard. In these and other embodiments, network interface 108 may
comprise a network interface card, or "NIC." In these and other
embodiments, network interface 108 may be enabled as a local area
network (LAN)-on-motherboard (LOM) card.
[0033] Management controller 112 may be configured to provide
management functionality for the management of information handling
system 102. Such management may be made by management controller
112 even if information handling system 102 and/or host system 98
are powered off or powered to a standby state. Management
controller 112 may include a processor 113, memory, and a network
interface 118 separate from and physically isolated from network
interface 108.
[0034] As shown in FIG. 1, processor 113 of management controller
112 may be communicatively coupled to processor 103. Such coupling
may be via a Universal Serial Bus (USB), System Management Bus
(SMBus), and/or one or more other communications channels.
[0035] Network interface 118 may be coupled to a management
network, which may be separate from and physically isolated from
the data network as shown. Network interface 118 of management
controller 112 may comprise any suitable system, apparatus, or
device operable to serve as an interface between management
controller 112 and one or more other information handling systems
via an out-of-band management network. Network interface 118 may
enable management controller 112 to communicate using any suitable
transmission protocol and/or standard. In these and other
embodiments, network interface 118 may comprise a network interface
card, or "NIC." Network interface 118 may be the same type of
device as network interface 108, or in other embodiments it may be
a device of a different type.
[0036] Information handling system 102 may include a storage medium
that is an integral part of the chassis thereof (e.g., disposed at
a front panel of the chassis). In particular, any storage medium
that is part of the chassis of information handling system 102
rather than part of a motherboard, backplane, etc. may be used for
this purpose, because such storage medium is physically separate
from management controller 112 (which would typically reside on the
motherboard or backplane of information handling system 102). In
some embodiments, such a storage medium may be implemented as front
panel serial peripheral interconnect (SPI) flash 115.
[0037] Management controller 112 may include a firmware 122
therein. For example, firmware 122 may be embodied in a solid-state
storage medium such as flash memory, EEPROM, etc.
[0038] As discussed above, the owner of information handling system
112 may desire to build and cryptographically sign their own image
for firmware 122 (e.g., based on an open source project such as
OpenBMC or the like).
[0039] Some embodiments of this disclosure may securely enable the
use of customer-signed firmware images for firmware 122 by
leveraging front panel SPI flash 115 to detect when a motherboard
has been moved to another information handling system chassis. This
may be done by leveraging a hidden root key (HRK) of management
controller 112, which may be unique to each processor 113. For
example, processor 113 may be a system on chip (SoC) that includes
the HRK embedded therein, and the HRK may be inaccessible by
firmware 122. For example, the HRK may be accessible only via a
hardware encryption engine in processor 113.
[0040] Turning now to FIG. 2, a flow chart is shown of an example
method 200 for enabling a customer-signed image for management
controller 112, in accordance with some embodiments of this
disclosure. In some embodiments, the various steps of method 200
may be carried out by management controller 112.
[0041] At step 202, during the enablement of a customer-signed
image for management controller 112, management controller 112 may
read the customer public key (CPK). In some embodiments, the
customer may provide the CPK to the vendor, such that the CPK may
be stored in the vendor uboot and thus accessible to management
controller 112.
[0042] At step 204, management controller 112 may read its MAC
address, which may be a fused MAC (FMAC) address that is not
changeable and may be stored in processor 113. Management
controller 112 may generate random nonce data (e.g., an
initialization vector (IV)) as well.
[0043] At step 206, management controller 112 may create a data
structure using the CPK, the FMAC, and the random nonce. The data
structure may then be encrypted at step 208 using the HRK to
generate an encrypted structure (ES). Any suitable type of
encryption (e.g., symmetric or asymmetric) may be used in
particular embodiments. The ES and the IV may then be stored in
front panel SPI flash 115 at step 210, and the method may end.
[0044] One of ordinary skill in the art with the benefit of this
disclosure will understand that the preferred initialization point
for the method depicted in FIG. 2 and the order of the steps
comprising that method may depend on the implementation chosen. In
these and other embodiments, this method may be implemented as
hardware, firmware, software, applications, functions, libraries,
or other instructions. Further, although FIG. 2 discloses a
particular number of steps to be taken with respect to the
disclosed method, the method may be executed with greater or fewer
steps than depicted. The method may be implemented using any of the
various components disclosed herein (such as the components of FIG.
1), and/or any other system operable to implement the method.
[0045] Turning now to FIG. 3, a flow chart is shown of an example
method 300 for booting management controller 112 after enablement
of customer-signed firmware, in accordance with some embodiments of
this disclosure.
[0046] At step 302, execution of the customer BMC runtime image
begins. At step 304, the vendor uboot may read the encrypted
structure and initialization vector from front panel SPI flash 115.
At step 306, the vendor uboot may decrypt the encrypted structure
with the HRK in order to obtain the CPK and the MAC address that
were stored in the encrypted structure (which may be referred to as
a "potential" CPK and a "potential" MAC address, to be compared
with known values).
[0047] At step 308, the vendor uboot may validate the decrypted CPK
from the encrypted structure against the CPK stored in the uboot;
the vendor uboot may also validate the MAC address from the
encrypted structure with the fused MAC address.
[0048] If these data match, it means that the motherboard has not
been moved to another chassis, and the vendor uboot may proceed to
chain load the customer firmware image at step 310.
[0049] If the data do not match, then the vendor uboot may disable
booting to the customer-signed image at step 312.
[0050] At step 314, it may be determined whether or not a
vendor-supplied backup image is available for firmware 122. If so,
it may be loaded at step 318 and boot may continue.
[0051] If such a backup image is not found, the vendor uboot may
halt the boot process and provide an error indication at step 316.
For example, error indications may include displaying an error
message on the video output, sending an error message over a serial
connector, sending network alerts (e.g., an SNMP trap), etc. At
step 320, method 300 may end.
[0052] One of ordinary skill in the art with the benefit of this
disclosure will understand that the preferred initialization point
for the method depicted in FIG. 3 and the order of the steps
comprising that method may depend on the implementation chosen. In
these and other embodiments, this method may be implemented as
hardware, firmware, software, applications, functions, libraries,
or other instructions. Further, although FIG. 3 discloses a
particular number of steps to be taken with respect to the
disclosed method, the method may be executed with greater or fewer
steps than depicted. The method may be implemented using any of the
various components disclosed herein (such as the components of FIG.
1), and/or any other system operable to implement the method.
[0053] Thus embodiments of this disclosure may provide many
benefits. For example, customer image signing may effectively be
automatically revoked when the motherboard is removed from the
chassis. Further, supply chain protection may be ensured via the
use of the HRK of management controller 112.
[0054] This disclosure encompasses all changes, substitutions,
variations, alterations, and modifications to the exemplary
embodiments herein that a person having ordinary skill in the art
would comprehend. Similarly, where appropriate, the appended claims
encompass all changes, substitutions, variations, alterations, and
modifications to the exemplary embodiments herein that a person
having ordinary skill in the art would comprehend. Moreover,
reference in the appended claims to an apparatus or system or a
component of an apparatus or system being adapted to, arranged to,
capable of, configured to, enabled to, operable to, or operative to
perform a particular function encompasses that apparatus, system,
or component, whether or not it or that particular function is
activated, turned on, or unlocked, as long as that apparatus,
system, or component is so adapted, arranged, capable, configured,
enabled, operable, or operative.
[0055] Further, reciting in the appended claims that a structure is
"configured to" or "operable to" perform one or more tasks is
expressly intended not to invoke 35 U.S.C. .sctn. 112(f) for that
claim element. Accordingly, none of the claims in this application
as filed are intended to be interpreted as having
means-plus-function elements. Should Applicant wish to invoke
.sctn. 112(f) during prosecution, Applicant will recite claim
elements using the "means for [performing a function]"
construct.
[0056] All examples and conditional language recited herein are
intended for pedagogical objects to aid the reader in understanding
the invention and the concepts contributed by the inventor to
furthering the art, and are construed as being without limitation
to such specifically recited examples and conditions. Although
embodiments of the present inventions have been described in
detail, it should be understood that various changes,
substitutions, and alterations could be made hereto without
departing from the spirit and scope of the disclosure.
* * * * *