BitLocker Windows Resume
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Security Policy
for FIPS 140‐2 Validation
Microsoft Windows 8
Microsoft Windows Server 2012
Microsoft Windows Storage Server 2012
Microsoft Surface Windows 8 Pro
BitLocker® Windows Resume
(WINRESUME)
DOCUMENT INFORMATION
Version Number 1.2
Updated On December 17, 2014
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This Security Policy is non‐proprietary and may be reproduced only in its original entirety (without revision).
The information contained in this document
represents the current view of Microsoft Corporation
on the issues discussed as of the date of publication.
Because Microsoft must respond to changing market
conditions, it should not be interpreted to be a
commitment on the part of Microsoft, and Microsoft
cannot guarantee the accuracy of any information
presented after the date of publication.
This document is for informational purposes only.
MICROSOFT MAKES NO WARRANTIES, EXPRESS
OR IMPLIED, AS TO THE INFORMATION IN THIS
DOCUMENT.
Complying with all applicable copyright laws is the
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© 2014 Microsoft Corporation. All rights reserved.
Microsoft, Windows, the Windows logo, Windows
Server, and BitLocker are either registered
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The names of actual companies and products
mentioned herein may be the trademarks of their
respective owners.
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TABLE OF CONTENTS
1 INTRODUCTION .................................................................................................................... 5
1.1 LIST OF CRYPTOGRAPHIC MODULE BINARY EXECUTABLES................................................................... 5
1.2 BRIEF MODULE DESCRIPTION....................................................................................................... 5
1.3 VALIDATED PLATFORMS ............................................................................................................. 7
1.4 CRYPTOGRAPHIC BOUNDARY ....................................................................................................... 7
2 SECURITY POLICY .................................................................................................................. 7
2.1 FIPS 140‐2 APPROVED ALGORITHMS.......................................................................................... 10
2.2 NON‐APPROVED ALGORITHMS .................................................................................................. 10
2.3 CRYPTOGRAPHIC BYPASS .......................................................................................................... 10
2.4 MACHINE CONFIGURATIONS...................................................................................................... 10
3 OPERATIONAL ENVIRONMENT............................................................................................ 10
4 INTEGRITY CHAIN OF TRUST................................................................................................ 10
4.1 CONVENTIONAL BIOS AND UEFI WITHOUT SECURE BOOT ENABLED .................................................. 10
4.2 UEFI WITH SECURE BOOT ENABLED ............................................................................................ 10
5 PORTS AND INTERFACES ..................................................................................................... 11
5.1 CONTROL INPUT INTERFACE....................................................................................................... 11
5.2 STATUS OUTPUT INTERFACE ...................................................................................................... 11
5.3 DATA OUTPUT INTERFACE......................................................................................................... 11
5.4 DATA INPUT INTERFACE............................................................................................................ 11
6 SPECIFICATION OF ROLES.................................................................................................... 11
6.1 MAINTENANCE ROLES .............................................................................................................. 11
6.2 MULTIPLE CONCURRENT INTERACTIVE OPERATORS......................................................................... 12
6.3 SHOW STATUS SERVICES........................................................................................................... 12
6.4 SELF‐TEST SERVICES................................................................................................................. 12
6.5 SERVICE INPUTS / OUTPUTS ...................................................................................................... 12
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7 CRYPTOGRAPHIC KEY MANAGEMENT ................................................................................. 12
7.1 ACCESS CONTROL POLICY.......................................................................................................... 12
8 SELF‐TESTS.......................................................................................................................... 12
8.1 POWER‐ON SELF TESTS ............................................................................................................ 12
8.2 CONDITIONAL SELF‐TESTS ......................................................................................................... 13
9 DESIGN ASSURANCE............................................................................................................ 13
10 MITIGATION OF OTHER ATTACKS........................................................................................ 14
11 ADDITIONAL DETAILS.......................................................................................................... 14
12 APPENDIX A – HOW TO VERIFY WINDOWS VERSIONS AND DIGITAL SIGNATURES ............... 15
12.1 HOW TO VERIFY WINDOWS VERSIONS......................................................................................... 15
12.2 HOW TO VERIFY WINDOWS DIGITAL SIGNATURES.......................................................................... 15
BitLocker Windows Resume
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1 Introduction
BitLocker ® Windows Resume, WINRESUME.EXE, is an operating system loader which loads the
Windows 8, Windows Server 2012, and Windows Storage Server 2012 operating system kernel
(ntoskrnl.exe) and other boot stage binary image files, as well as previous operating system state
information, when Windows has been previously put into a sleep (S3) or hibernate (S4) power state.
Throughout this document, BitLocker ® Windows Resume may be called Windows Resume for short.
1.1 List of Cryptographic Module Binary Executables
WINRESUME.EXE – Version 6.2.9200 for Windows 8, Windows Server 2012, and Windows Storage
Server 2012 on systems using conventional BIOS.
WINRESUME.EFI – Version 6.2.9200 for Windows 8, Windows Server 2012, and Windows Storage Server
2012 on systems using UEFI firmware.
1.2 Brief Module Description
Windows Resume is the binary executable that handles loading the Windows operating system when
resuming from hibernation. At resume time, if BitLocker is enabled, the encrypted hibernation data is
decrypted as it is paged back into memory.
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TPM
chip
TPM.SYS
TBS.DLL
TPM Base Services
WIN32_TPM.DLL
TPM WMI
Provider
TPM MMC SnapIn
TPM Initialization
Wizard
FVEAPI.DLL
MBR Boot Code
BootMgr
WINLOAD.EXE/
WINRESUME.EXE
Shared memory /
Key Ring
Ntfs Boot Code
FVEVOL.SYS
NTOSKRNL.EXE
CI.DLL
I/O Manager
File System
Volume Manager
DUMPFVE.SYS
Partition Manager Partition Manager Partition Manager
SCSI / Mini Port USBStor SD / Mini Port
Harddisk USB storage device
Flash disk
SD card
BIOS
Smart card
reader / Smart
card
BitLockerWizard.Exe
FVE Setup Wizard
BdeUnlockWizard.Exe
FVE Unlock Wizard
FveNotify.Exe
FvePrompt.Exe
Fvecpl.dll
FVEUI.DLL
FVECERT.DLL
BdeSvc.Dll
BitLocker Service
AD
Smart Card Picker
Certificate UI
Certificate Picker
Crypt32.dll
Ncrypt.dll
Bcrypt.dll
Bcryptprimitives.dll
Win32_Encryptable
Volume.Dll
FVE WMI Provider
Manage‐Bde.Exe
‐ Key material flow
‐ Control flow
‐ IO flow
Figure 1 - Logical Operation of Module (this cryptographic module is in orange, other
BitLocker-related cryptographic modules are in blue)
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1.3 Validated Platforms
The Windows Resume components listed in Section 1.1 were validated using the following machine
configurations:
x86 Microsoft Windows 8 Enterprise – Dell Dimension C521 (AMD Athlon 64 X2 Dual Core)
x64 Microsoft Windows 8 Enterprise – Dell PowerEdge SC430 (Intel Pentium D without AES‐NI)
x64‐AES‐NI Microsoft Windows 8 Enterprise – Intel Client Desktop (Intel Core i7 with AES‐NI )
x64 Microsoft Windows Server 2012 – Dell PowerEdge SC430 (Intel Pentium D without AES‐NI)
x64‐AES‐NI Microsoft Windows Server 2012 – Intel Client Desktop (Intel Core i7 with AES‐NI)
x64‐AES‐NI Microsoft Windows 8 Pro – Microsoft Surface Windows 8 Pro (Intel x64 Processor
with AES‐NI)
x64 Microsoft Windows Storage Server 2012 – Intel Maho Bay (Intel Core i7 without AES‐NI)
x64‐AES‐NI Microsoft Windows Storage Server 2012 – Intel Maho Bay (Intel Core i7 with AES‐NI)
Windows Resume maintains FIPS 140‐2 validation compliance (according to FIPS 140‐2 PUB
Implementation Guidance G.5) on the following platforms:
x86 Microsoft Windows 8
x86 Microsoft Windows 8 Pro
x64 Microsoft Windows 8
x64 Microsoft Windows 8 Pro
x64 Microsoft Windows Server 2012 Datacenter
x64‐AES‐NI Microsoft Windows 8
x64‐AES‐NI Microsoft Windows 8 Pro
x64‐AES‐NI Microsoft Windows Server 2012 Datacenter
1.4 Cryptographic Boundary
The software cryptographic boundary for Windows Resume is defined as the binaries WINRESUME.EXE
and WINRESUME.EFI.
2 Security Policy
Windows Resume operates under several rules that encapsulate its security policy.
 Windows Resume is validated on Windows 8 running on x86 and x64.
 Windows Resume maintains FIPS 140‐2 validation compliance on Windows Server 2012 running
on x64.
 Windows Resume operates in FIPS mode of operation only when used with the FIPS validated
version of Windows 8, Windows Server 2012, and Windows Storage Server 2012 Boot Manager
(bootmgr) validated to FIPS 140‐2 under Cert. #1895 operating in FIPS mode.
 Windows 8, Windows Server 2012, and Windows Storage Server 2012 are operating systems
supporting a “single user” mode where there is only one interactive user during a logon session.
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 Windows Resume is only in its Approved mode of operation when Windows is booted normally,
meaning Debug mode is disabled and Driver Signing enforcement is enabled.
 The Debug mode status and Driver Signing enforcement status can be viewed by using the
bcdedit tool.

The following diagram illustrates the master components of the Windows Resume module:
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The following diagram illustrates Windows Resume module interaction with other cryptographic
modules:
 Windows Resume’s main service is to load the Windows 8, Windows Server 2012, and Windows
Storage Server 2012 operating system kernel (ntoskrnl.exe) and other boot stage binary image
files, including Code Integrity cryptographic module (ci.dll), after it validates their integrity using
its cryptographic algorithm implementations using the FIPS 140‐2 approved algorithms
mentioned below. After the verified kernel and boot stage binary image files, including Code
Integrity, are loaded, Windows Resume passes the execution control to the kernel and it
terminates its own execution. In addition to this service, Windows Resume also provides status
and self‐test services. The Crypto officer and User have access to all services WINRESUME
supports.
 If the integrity of the kernel or Code Integrity is not verified, Windows Resume does not transfer
the execution to the kernel.
 The module provides a power‐up self‐tests service that is automatically executed when the
module is loaded into memory. The module also provides a show status service that is
automatically executed by the module to provide the status response of the module either via
output to the GPC monitor or to log files.
 Windows Resume verifies the integrity of multiple kernel mode crypto modules. This verification
relies on RSA 2048‐bit signature verification using SHA‐256. If the verification fails, the modules
are not loaded into memory, and this will prevent Windows from booting. The following binaries
are verified in this manner:
o CI.DLL
o CNG.SYS
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2.1 FIPS 140‐2 Approved Algorithms
Windows Resume implements the following FIPS‐140‐2 Approved algorithms:
 RSA PKCS#1 (v1.5) digital signature verification (Cert. # 1132)
o RSA signature verification with 1024‐bit keys and SHA‐1 message digest
o RSA signature verification with 2048‐bit keys and SHA‐256 message digest
 SHS (SHA‐1) (Cert. # 1903)
 SHS (SHA‐256) (Cert. # 1903)
 SHS (SHA‐384) (Cert. # 1903)
 SHS (SHA‐512) (Cert. # 1903)
 AES (Certs. # 2196 and # 2198)
2.2 Non‐Approved Algorithms
Windows Resume also includes a legacy implementation of MD5.
2.3 Cryptographic Bypass
Cryptographic bypass is not supported by Windows Resume.
2.4 Machine Configurations
BitLocker Windows Resume was tested using the machine configurations listed in Section 1.3 ‐ Validated
Platforms.
3 Operational Environment
The operational environment for Windows Resume is Windows 8, Windows Server 2012, and Windows
Storage Server 2012 running on the hardware listed in Section 1.3 ‐ Validated Platforms. Windows
Resume services are only available before the startup of the operating system. This is done inside the
Trusted Computing Base (TCB).
4 Integrity Chain of Trust
4.1 Conventional BIOS and UEFI without Secure Boot Enabled
Boot Manager is the start of the chain of trust. It cryptographically checks its own integrity during its
startup. It then cryptographically checks the integrity of Windows Resume (if resuming from
hibernation) before starting it. Windows Resume then checks the integrity of the Code Integrity crypto
module, the operating system kernel, and other boot stage binary images. An RSA signature with a
2048‐bit key and SHA‐256 message digest are used.
4.2 UEFI with Secure Boot Enabled
On UEFI systems with Secure Boot enabled, Boot Manager is still the OS binary from which the integrity
of all other OS binaries is rooted, and it does cryptographically check its own integrity. However, Boot
Manager’s integrity is also checked and verified by the UEFI firmware, which is the root of trust on
Secure Boot enabled systems. An RSA signature with a 2048‐bit key and SHA‐256 message digest are
used.
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5 Ports and Interfaces
5.1 Control Input Interface
The Windows Resume Control Input Interface is the set of internal functions responsible for intercepting
control input. These functions are:
 BlBdInitialize – Reads the system status to determine if a boot debugger is attached.
 OslMain – This function receives and parses the Boot Application parameters, which are passed
to the module when execution is passed from Boot Manager.
 BlInitializeLibrary – Performs the parsing Boot Application parameters.
 BlXmiRead – Reads the operator selection from the Winload user interface.
5.2 Status Output Interface
The Status Output Interface is the BlXmiWrite function that is responsible for displaying the integrity
verification errors to the screen. The Status Output Interface is also defined as the BlLogData
responsible for writing the name of the corrupt driver to the bootlog.
5.3 Data Output Interface
The Data Output Interface is represented by the OslArchTransferToKernel function and the
AhCreateLoadOptionsString function. OslArchTransferToKernel is responsible for transferring the
execution from Winresume to the initial execution point of the Windows 8, Windows Server 2012, and
Windows Storage Server 2012 kernel. Data exits the module in the form of the initial instruction address
of the Windows 8, Windows Server 2012, and Windows Storage Server 2012 kernel.
Data exits the module from the AhCreateLoadOptionsString function in the form of boot application
parameters passed to the Windows 8, Windows Server 2012, and Windows Storage Server 2012 kernel.
5.4 Data Input Interface
The Data Input Interface is represented by the BlFileReadEx function and the BlDeviceRead function.
BlFileReadEx is responsible for reading the binary data of unverified components from the computer
hard drive. In addition the BitLocker Full Volume Encryption Key (FVEK) can also be entered into the
module over the module’s data input interface. BlDeviceRead is responsible for reading data directly
from devices.
6 Specification of Roles
Windows Resume supports both User and Cryptographic Officer roles (as defined in FIPS‐140‐2). Both
roles have access to all services implemented in Windows Resume. The module does not implement any
authentication services. Therefore, roles are assumed implicitly by booting the Windows 8, Windows
Server 2012, and Windows Storage Server 2012 operating systems.
6.1 Maintenance Roles
Maintenance roles are not supported.
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6.2 Multiple Concurrent Interactive Operators
There is only one interactive operator in Single User Mode. When run in this configuration, multiple
concurrent interactive operators are not supported.
6.3 Show Status Services
The User and Cryptographic Officer roles have the same Show Status functionality, which is, for each
function, the status information is returned to the caller as the return value from the function.
6.4 Self‐Test Services
The User and Cryptographic Officer roles have the same Self‐Test functionality, which is described in
Section 8 Self‐Tests.
6.5 Service Inputs / Outputs
The User and Cryptographic Officer roles have service inputs and outputs as specified in Section 5 Ports
and Interfaces.
7 Cryptographic Key Management
Windows Resume does not store any secret or private cryptographic keys across power‐cycles.
However, it does use two AES keys in support of the BitLocker feature. These keys are:
 Full Volume Encryption Key (FVEK) ‐ 128 or 256‐bit AES key that is used to decrypt data on disk
sectors of the hard drive.
This key is stored in memory and is zeroized by power‐cycling the OS.
Windows Resume also uses public keys stored on the computer hard disk to verify digital signatures
using its implementation of RSA PKCS#1 (v1.5) verify. These public keys are available to both roles.
Zeroization is performed by deleting the Winload module.
7.1 Access Control Policy
All the keys (mentioned above) are accessed only by the Windows Resume service that loads the
operating system kernel (ntoskrnl.exe) and other boot stage binary image files, including Code Integrity.
This service only has execute access to the keys mentioned above. Due to such simplicity, an access
control policy table is not included in this document.
8 Self‐Tests
8.1 Power‐On Self Tests
Windows Resume performs the following power‐on (startup) self‐tests:
 SHS (SHA‐1) Known Answer Test
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 SHS (SHA‐256) Known Answer Test
 SHS (SHA‐512) Known Answer Test
 RSA PKCS#1 (v1.5) verify with public key
o RSA signature with 1024‐bit key and SHA‐1 message digest
o RSA signature with 2048‐bit key and SHA‐256 message digest
 AES encrypt and decrypt Known Answer Tests
If the self‐test fails, the module will not load and status will be returned. If the status is not
STATUS_SUCCESS, then that is the indicator a self‐test failed.
8.2 Conditional Self‐Tests
Windows OS Loader does not perform conditional self‐tests.
9 Design Assurance
The secure installation, generation, and startup procedures of this cryptographic module are part of the
overall Windows 8, Windows Server 2012, and Windows Storage Server 2012 operating system secure
installation, configuration, and startup procedures. After the operating system has been installed, it
must be configured by enabling the "System cryptography: Use FIPS compliant algorithms for
encryption, hashing, and signing" policy setting followed by restarting the system. This procedure is all
the crypto officer and user behavior necessary for the secure operation of this cryptographic module.
The procedures required for maintaining security while distributing and delivering versions of a
cryptographic module to authorized operators are:
1. The secure distribution method is via the physical medium for product installation delivered by
Microsoft Corporation, which is a DVD in the case of Windows 8, Windows Server 2012, and
Windows Storage Server 2012. In the case of Surface Windows 8 Pro, the cryptographic module
is already installed at the factory and is only distributed with the hardware.
2. An inspection of authenticity of the physical medium can be made by following the guidance at
this Microsoft web site: http://www.microsoft.com/en‐us/howtotell/default.aspx
3. The installed version of Windows 8, Windows Server 2012, and Windows Storage Server 2012
must be verified to match the version that was validated. See Appendix A for details on how to
do this.
For Windows Updates, the client only accepts binaries signed by Microsoft certificates. The Windows
Update client only accepts content whose SHA‐2 hash matches the SHA‐2 hash specified in the
metadata. All metadata communication is done over a Secure Sockets Layer (SSL) port. Using SSL
ensures that the client is communicating with the real server and so prevents a spoof server from
sending the client harmful requests. The version and digital signature of new cryptographic module
releases must be verified to match the version that was validated. See Appendix A for details on how to
do this.
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10 Mitigation of Other Attacks
The following table lists the mitigations of other attacks for this cryptographic module:
Algorithm Protected
Against
Mitigation Comments
SHA1 Timing
Analysis
Attack
Constant Time Implementation
Cache Attack Memory Access pattern is
independent of any
confidential data
SHA2 Timing
Analysis
Attack
Constant Time Implementation
Cache Attack Memory Access pattern is
independent of any
confidential data
AES Timing
Analysis
Attack
Constant Time Implementation
Cache Attack Memory Access pattern is
independent of any
confidential data
Protected Against Cache
attacks only when used with
AES NI
11 Additional Details
For the latest information on Microsoft Windows, check out the Microsoft web site at:
http://windows.microsoft.com
For more information about FIPS 140 evaluations of Microsoft products, please see:
http://technet.microsoft.com/en‐us/library/cc750357.aspx
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12 Appendix A – How to Verify Windows Versions and Digital Signatures
12.1 How to Verify Windows Versions
The installed version of Windows 8, Windows Server 2012, and Windows Storage Server 2012 must be
verified to match the version that was validated using one of the following methods:
1. The ver command
a. From Start, open the Search charm.
b. In the search field type "cmd" and press the Enter key.
c. The command window will open with a "C:\>" prompt.
d. At the prompt, type "ver" and press the Enter key.
e. You should see the answer "Microsoft Windows [Version 6.2.9200]".
2. The systeminfo command
a. From Start, open the Search charm.
b. In the search field type "cmd" and press the Enter key.
c. The command window will open with a "C:\>" prompt.
d. At the prompt, type "systeminfo" and press the Enter key.
e. Wait for the information to be loaded by the tool.
f. Near the top of the output, you should see:
OS Name: Microsoft Windows 8 Enterprise
OS Version: 6.2.9200 N/A Build 9200
OS Manufacturer: Microsoft Corporation
If the version number reported by the utility matches the expected output, then the installed version
has been validated to be correct.
12.2 How to Verify Windows Digital Signatures
After performing a Windows Update that includes changes to a cryptographic module, the digital
signature and file version of the binary executable file must be verified. This is done like so:
1. Open a new window in Windows Explorer.
2. Type “C:\Windows\” in the file path field at the top of the window.
3. Type the cryptographic module binary executable file name (for example, “CNG.SYS”) in the
search field at the top right of the window, then press the Enter key.
4. The file will appear in the window.
5. Right click on the file’s icon.
6. Select Properties from the menu and the Properties window opens.
7. Select the Details tab.
8. Note the File version Property and its value, which has a number in this format: x.x.xxxx.xxxxx.
9. If the file version number matches one of the version numbers that appear at the start of this
security policy document, then the version number has been verified.
10. Select the Digital Signatures tab.
11. In the Signature list, select the Microsoft Windows signer.
12. Click the Details button.
13. Under the Digital Signature Information, you should see: “This digital signature is OK.” If that
condition is true then the digital signature has been verified.