sSSSSs FFFFFFFFFF sSSSSs sSSSSSSs FFFFFFFFF sSSSSSSs sSs sS FF sSs sS SS FF SS sSs FF sSs sSSSSSSs FFFFFFF sSSSSSSs sSs FF sSs SS FF SS Ss Ss FF Ss Ss sSSSSSSs FF sSSSSSSs sSSSSs FF sSSSSs S e c u r e F i l e S y s t e m Version 1.20 Copyright Peter C.Gutmann 1993, 1994, 1995 "The right to privacy... is the most comprehensive of rights and the right most valued by civilized man" - Justice Louis Brandeis, US Supreme Court, 1928 Ever since Julius Caesar used the cipher which now bears his name to try to hide his military dispatches from prying eyes, people have been working on various means to keep their confidential information private. O...

Creating an SFS Volume Before SFS can use an disk volume, you will need to convert it from a normal DOS volume into an encrypted SFS one. The program does this is mksfs (Make Secure Filesystem), which is very loosely patterned after the Unix mkfs utility. mksfs takes a standard DOS volume (which may be either freshly formatted or may already contain files) and turns in into an encrypted SFS one. The encryption process is non-destructive, so you won't lose any information already on the volume, except for the (fortunately very rare) case of there being a power cut while the encryption is taking place (this means that power to the syst...

Advanced SFS Driver Options The SFS driver supports several advanced options which can be used to customize the operation of SFS. These include the ability to mount SFS volumes automatically when the driver is loaded, the ability to echo passwords to the screen as they are entered, and the ability to change the read/write status, disk access mode, auto-unmount timeout of mounted volumes, quick-unmount hotkey, and the password prompt used when mounting volumes. Mounting SFS Volumes at System Startup You can mount SFS volumes automatically when the system is started up rather than having to use the mountsfs program or SFS Control Panel...

Controlling SFS Volumes with Smart Cards Requiring the entry of a complex pass phrase to allow access to an SFS volume can be troublesome since not everyone will be able to remember, and want to type in, long complicated passwords. As a result, people may be tempted to write them down, or choose simple passwords which are easily guessed. In order to ease this problem, SFS supports the use of passwords stored in physical devices such as smart cards and cryptographic ignition keys or datakeys. The simplest way to store a password in a physical device is on a magnetic stripe card similar to a credit card or ATM card. Unfortunately these car...

The Care and Feeding of Passwords With the inherent strength of an encryption system like the one used by SFS, the password used for encryption is becoming more the focus of attack than the encryption system itself. The reason for this is that trying to guess an encryption password is far simpler than trying to break the encryption system. SFS allows keys of up to 100 characters in length. These keys can contain letters, numbers, spaces, punctuation, and most control and extended characters except backspace (which is used for editing), escape (which is used to abort the password entry), and carriage return or newline, which are used to s...

Politics Many governments throughout the world have an unofficial policy on cryptography which is to reserve all knowledge and use of encryption to the government in general and the elite in particular. This means that encryption is to be used firstly (in the form of restrictions on its use) for intelligence-gathering, and secondly for protecting the secret communications of the government. The government therefore uses encryption to protect its own dealings, but denies its citizens the right to use it to protect their own privacy, and denies companies the right to use it to protect their business data. Only a very small number of countr...

Design Details This section goes into a few of the more obscure details not covered in the section on security analysis, such as the encryption algorithm used by SFS, the generation of random numbers, the handling of initialization vectors (IV's), and a brief overview on the deletion of sensitive information retained in memory after a program has terminated (this is covered in more detail in the section "Security Analysis" above). The Encryption Algorithm used in SFS Great care must be taken when choosing an encryption algorithm for use in security software. For example, the standard Unix crypt(1) command is based on a software imple...

SFS Disk Volume Layout An SFS volume is broken up into two parts, the boot sector which is used to identify the volume and store assorted status information, and the encrypted volume itself. If a program tries to read the boot sector, the SFS driver will assemble a pseudo-boot sector in memory and return that instead. If a program tries to write to the boot sector, the SFS driver will skip the boot sector while still writing any other sectors which may be requested. All data on the boot sector, both plaintext and encrypted, is stored in big-endian format following the convention used by international cryptographic standards. Care should ...

Interfacing with mountsfs In order to facilitate the use of SFS with other software such as graphical front-ends, mountsfs has the ability to be run in batch mode in which it will accept abbreviated forms of the usual commands and output more complex results to data files instead of to the screen. External software can then parse the mountsfs output and report the results back to the user. This is how WinSFS performs the task of scanning for SFS volumes, since using direct disk access to do this under Windows is virtually impossible. Controlling mountsfs in Batch Mode You can enable the use of batch mode by giving mountsfs the keyword `b...

CHAPTER 1 - Introduction 01.01 Product Description 01.02 Using This Manual 01.03 System Requirements 01.01 Product Description Soft-ICE is a software debugging tool that provides hardware-level debugging capabilities to PCDOS and MSDOS debuggers. Soft-ICE uses 80386 protected mode to run DOS in a virtual machine. This gives Soft-ICE complete control of the DOS environment. Soft-ICE uses 80386 protected mode features, such as paging, I/O privilege level, and break point registers, to add hardware-level break points your existing DOS debugger. Soft-ICE was designed with three goals in mind: * To utilize the 80386 virtual machine capability...

CHAPTER 2 - Getting Started 02.01 The Diskettes 02.02 Loading Soft-ICE 02.02.01 Loading Without Extended Memory 02.02.02 Loading With Extended Memory 02.02.03 Configuring Soft-ICE for a Customized Installation 02.03 Unloading Soft-ICE 02.04 Reloading Soft-ICE 02.01 The Diskettes Soft-ICE comes on either a 5 1/4" diskette or a 3 1/2" diskette. When you run Soft-ICE, the name of the person that your copy of Soft-ICE is licensed to is displayed on the screen as a deterrent to software pirates. The Soft-ICE diskette is not physically copy-protected for your convenience. For our convenience, we appreciate your high regard for our licensing ag...

CHAPTER 3 - Debugging In 30 Minutes 03.01 Introduction 03.02 Popping Up the Window 03.03 Returning From the Window 03.04 Changing the Window Size 03.05 Moving the Window 03.06 Line Editing Keystrokes 03.07 Interactive Status Line 03.08 Command Syntax 03.08.01 Specifying Memory Addresses 03.09 Function Keys 03.10 Help 03.11 Tutorial 03.01 Introduction All interaction with Soft-ICE takes place through a window that can be popped up at any time. All Soft-ICE commands fit in a small window, but the window can be enlarged to full screen. You will typically use the small window when using Soft-ICE as an assistant to another debugger, and the l...

CHAPTER 4 - Using Break Point Commands 04.00 Notationnal Conventions 04.01 Introduction 04.02 Setting Break Points 04.03 Manipulating Break Points 04.00 Notationnal Conventions Section II contains syntax listings for each Soft-ICE command, and explanations and examples for each command. All numbers are in hexadecimal; any number can be an expression using +,-,/,*, or registers. All commands are case-insensitive. Words that are in italics the command syntax statements must be replaced by an actual value, rather than typing in the italicized word. The following notational conventions are used throughout this section [ ] Brackets enclose an...

CHAPTER 5 - Using Other Commands 05.01 Display and Edit Commands 05.02 I/O Port Commands 05.03 Transfer Control Commands 05.04 Debug Mode Commands 05.05 Utility Commands 05.06 Specialized Debugging Commands 05.07 Windowing Commands 05.08 Debugger Customization Commands 05.09 Screen Control Commands 05.10 Symbol and Source Line Commands 05.01 Display and Edit Commands U Unassemble instructions or display source R Display or change registers MAP Display system memory map D, DB, DW, DD Display memory E, EB, EW, ED Edit memory INT? Display last interrupt number ? or H Display help information VER Display Soft-ICE version number Unassemble in...

CHAPTER 6 - Soft-ICE Initialization Options 06.01 Introduction 06.02 Loading Soft-ICE from the DOS Prompt 06.03 Loading Soft-ICE as a Loadable Device Driver 06.03.01 Soft-ICE Loading Switches 06.04 The Soft-ICE Initialization File S-ICE.DAT 06.04.01 Special Configuration Options 06.04.02 Function Key Assignments 06.04.03 Initialization Command Sequence 06.01 Introduction The Soft-ICE program file (S-ICE.EXE) can be loaded as a loadable device driver in CONFIG.SYS or as a program from the DOS command line. To get the full power of Soft-ICE, it must be initially loaded as a device driver in CONFIG.SYS. However, there may be circumstances w...

CHAPTER 7 - Symbolic and Source Level Debugging 07.01 Introduction 07.02 Preparing for Symbolic or Source Debugging 07.02.01 Preparing for Symbolic Debugging Only 07.02.02 Preparing for Symbolic and Source Level Debugging 07.03 Reserving Memory for Symbols and Source Files 07.04 Loading Programs and Symbol Files 07.04.01 Loading Program, Symbols and Source 07.04.02 Loading Only Symbols and Source Files 07.04.03 Loading a Program With No Symbols or Source 07.05 Debugging With Symbols 07.06 Debugging With Source 07.06.01 Using Line Numbers 07.06.02 Using Source Mode in the Code Window 07.01 Introduction Soft-ICE can load programs, symbol t...

CHAPTER 8 - Expanded Memory Support 08.01 Introduction 08.02 Configuring the EMM Environment 08.02.01 Default EMM Pages 08.02.02 Customizing the EMM Page Map 08.02.02.01 Including and Excluding Areas from EMM 08.03 Other EMM Features 08.03.01 Increasing Conventional Memory 08.03.02 Automatic Page Frame Locating 08.04 EMM Debugging 08.01 Introduction Soft-ICE has an expanded memory manager built into its kernel. The Soft- ICE expanded memory manager supports the Lotus-Intel-Microsoft 4.0 specification. This Soft-ICE feature is useful if you are using programs that support the EMM specification, or if you must backfill your conventional me...

CHAPTER 9 - Back Trace Ranges 09.01 Introduction 09.02 Using Back Trace Ranges 09.03 Special Notes 09.01 Introduction Soft-ICE can collect instruction information in a back trace history buffer as your program executes. These instructions can then be displayed after a bug has occurred. This allows you to go back and retrace a program's action to determine the actual flow of instructions preceding a break point. Instruction information is collected on accesses within a specified address range, rather than system wide. The ranges can be from 1 byte to 1 megabyte, so if desired, complete system information can be obtained. Using specific ra...

CHAPTER 10 - Using Soft-ICE with MagicCV or MagicCVW 10.01 Introduction 10.02 Running Soft-ICE with MagicCV or MagicCVW 10.03 Special Considerations 10.04 The Soft-ICE ACTION command 10.01 Introduction MagicCV allows you to run Microsoft's CodeView in less than 8K of conventional memory on your 80386 machine. MagicCVW allows you to run Microsoft's CodeView for Windows in less than 8K of conventional memory on your 80386 machine. Using Soft-ICE in combination with MagicCV or MagicCVW allows you to have the power of Soft-ICE while still having the convenience of using the CodeView product that you are familiar with. In the rest of this cha...

CHAPTER 11 - Advanced Features 11.01 Using Soft-ICE with other Debuggers 11.01.01 Debuggers that Use DOS 11.01.02 ACTION Command with other Debuggers 11.01.03 Special Considerations 11.01.04 Using Soft-ICE with CODEVIEW 11.01.05 Debuggers that Use 80386 Break Point Registers 11.02 User-Qualified Break Points 11.02.01 Example of a User-Qualified Break Point 11.03 The Window in Graphics Mode 11.04 Expanded Memory Debugging Features 11.05 Extended Memory Debugging Features 11.01 Using Soft-ICE with other Debuggers Soft-ICE was designed to work well with other debuggers. Each debugger offers different features, and therefore can require spec...