Advanced Hardware Hacking Techniques DEFCON 12 Friday, July 30

Advanced Hardware Hacking Techniques DEFCON 12 Friday, July 30 Joe Grand (Kingpin) [email protected]

Agenda 2 The "What" and "Why" of Hardware Hacking Enclosure & Mechanical Attacks Electrical Attacks Final Thoughts and Conclusions 2004 Grand Idea Studio, Inc.

What is Hardware Hacking (to me)? Doing something with a piece of hardware that has never been done before – – – – 3 Personalization and customization (e.g., "hot rodding for geeks") Adding functionality Capacity or performance increase Defeating protection and security mechanisms (not for profit) Creating something extraordinary Harming nobody in the process 2004 Grand Idea Studio, Inc.

Why Hardware Hacking? Curiosity – Improvement and Innovation – – Make products better/cooler Some products are sold to you intentionally limited or "crippled" Consumer Protection – 4 To see how things work I don't trust glossy marketing brochures.do you? 2004 Grand Idea Studio, Inc.

Hardware Security Myths 5 Many security-related products rely on misconceptions to remain "secure" Hardware hacking is hard Consumers lack the competency or courage to void their warranty Therefore, hardware is "safe" 2004 Grand Idea Studio, Inc.

Gaining Access to a Product Purchase – Evaluation – Product is in active operation, not owned by attacker Remote Access – 6 Rent or borrow the product Active – Buy the product from a retail outlet (with cash) No physical access to product, attacks launched remotely 2004 Grand Idea Studio, Inc.

Attack Vectors Interception (or Eavesdropping) – Interruption (or Fault Generation) – Tampering with the product, typically invasive Fabrication – 7 Preventing the product from functioning normally Modification – Gain access to protected information without opening the product Creating counterfeit assets of a product 2004 Grand Idea Studio, Inc.

Enclosure & Mechanical Attacks 8 Opening Housings External Interfaces Anti-Tamper Mechanisms Conformal Coating and Epoxy Encapsulation Removal 2004 Grand Idea Studio, Inc.

Opening Housings 9 Goal is to get access to internal circuitry Usually as easy as loosening some screws or prying open the device 2004 Grand Idea Studio, Inc.

Opening Housings 2 If glue is used to seal housing, use heat gun to soften glue and pry open with a knife – – 10 Some designers use glue with a high-melting point - enclosure will melt/deform before the glue does Some devices are sonically-welded to create a one-piece outer shell If done properly, will require destruction of device in order to open it 2004 Grand Idea Studio, Inc.

Opening Housings 3 Security bits and one-way screws – – – – 11 Used to prevent housings from being easily opened Ex.: Bathroom stalls, 3.8mm and 4.5mm security bit for Nintendo and Sega game cartridges/systems To identify a particular bit type, visit www.lara.com/reviews/screwtypes.htm Bits available at electronics stores, swapmeets, online 2004 Grand Idea Studio, Inc.

External Interfaces Usually a product's lifeline to the outside world – – Wireless interfaces also at risk (though not discussed here) – Ex.: 802.11b, Bluetooth Any interface that connects to a third-party may contain information that is useful for an attack – 12 Manufacturing tests, field programming/upgrading, peripheral connections Ex.: JTAG, RS232, USB, Firewire, Ethernet Could possibly obtain data, secrets, etc. 2004 Grand Idea Studio, Inc.

External Interfaces 2 Look for obfuscated interfaces – 13 Ex.: Proprietary or out-of-the-ordinary connector types, hidden access doors or holes Many times, test points just hidden by a sticker 2004 Grand Idea Studio, Inc.

External Interfaces 3 Use multimeter or oscilloscope to probe and determine functionality – – Monitor communications using H/W or S/W-based protocol analyzer – – USB: SnoopyPro RS232 and parallel port: PortMon Send intentionally malformed/bad packets to cause a fault – 14 Logic state of pins can help with an educated guess Ex.: Pull pins high or low, observe results, repeat If firmware doesn't handle this right, device could trigger unintended operation useful for an attack 2004 Grand Idea Studio, Inc.

External Interfaces: Backdoors Architecture-specific debug and test interfaces (usually undocumented) Diagnostic serial ports – – Developer's backdoors – – – 15 Provides information about system, could also be used for administration Ex.: Intel NetStructure crypto accelerator administrator access [1] Commonly seen on networking equipment, telephone switches Ex.: Palm OS debug mode [2] Ex.: Sega Dreamcast CD-ROM boot 2004 Grand Idea Studio, Inc.

External Interfaces: JTAG JTAG (IEEE 1149.1) interface is often the Achilles' heel Industry-standard interface for testing and debugging – Can provide a direct interface to hardware – – 16 Ex.: System-level testing, boundary-scanning, and lowlevel testing of dies and components Has become a common attack vector Ex.: Flash memory reprogramming on Pocket PC devices (www.xda-developers.com/jtag) 2004 Grand Idea Studio, Inc.

External Interfaces: JTAG 2 Five connections (4 required, 1 optional): TDO Data Out (from target device) TDI Data In (to target device) TMS Test Mode Select TCK Test Clock /TRST Test Reset (optional) H/W interface to PC can be built with a few dollars of off-the-shelf components – Ex.: www.lart.tudelft.nl/projects/jtag, http://jtagarm9.sourceforge.net/circuit.txt, or ftp://www.keithkoep.com/pub/arm-tools/jtag/ jtag05 sch.pdf 17 2004 Grand Idea Studio, Inc.

External Interfaces: JTAG 3 JTAG Tools (http://openwince.sourceforge.net/jtag) serves as the S/W interface on the PC Removing JTAG functionality from a device is difficult – 18 Designers usually obfuscate traces, cut traces, or blow fuses, all of which can be repaired by an attacker 2004 Grand Idea Studio, Inc.

Anti-Tamper Mechanisms Primary facet of physical security for embedded systems Attempts to prevent unauthorized physical or electronic tampering against the product Most effectively used in layers Possibly bypassed with knowledge of method – 19 Purchase one or two devices to serve as "sacrificial lambs" 2004 Grand Idea Studio, Inc.

Anti-Tamper Mechanisms 2 Tamper Resistance – – Tamper Evidence – – – 20 Specialized materials used to make tampering difficult Ex.: One-way screws, epoxy encapsulation, sealed housings Ensure that there is visible evidence left behind by tampering Only successful if a process is in place to check for deformity Ex.: Passive detectors (seals, tapes, glues), special enclosure finishes (brittle packages, crazed aluminum, bleeding paint) 2004 Grand Idea Studio, Inc.

Anti-Tamper Mechanisms 3 Tamper Detection – – – – 21 Enable the hardware device to be aware of tampering Switches: Detect the opening of a device, breach of security boundary, or movement of a component Sensors: Detect an operational or environmental change Circuitry: Detect a puncture, break, or attempted modification of the security envelope 2004 Grand Idea Studio, Inc.

Anti-Tamper Mechanisms 4 Tamper Response – – Physical Security Devices for Computer Subsystems [3] provides comprehensive attacks and countermeasures – 22 Countermeasures taken upon the detection of tampering Ex.: Zeroize critical memory, shutdown/disable/destroy device, enable logging features Ex.: Probing, machining, electrical attacks, physical barriers, tamper evident solutions, sensors, response technologies 2004 Grand Idea Studio, Inc.

Conformal Coating and Epoxy Encapsulation Removal 23 Encapsulation used to protect circuitry from moisture, dust, mold, corrosion, or arcing Epoxy or urethane coatings leave a hard, difficult to remove film 2004 Grand Idea Studio, Inc.

Conformal Coating and Epoxy Encapsulation Removal 2 The good news: The coatings are not specifically designed for security – Brute force approach: Dremel tool and wooden skewer as a drill bit – – 24 Can usually be bypassed with special chemicals like MG Chemicals' 8310 Conformal Coating Stripper (www.mgchemicals.com) Doesn't damage the components underneath coating Might remove the soldermask, but not a big deal. 2004 Grand Idea Studio, Inc.

Conformal Coating and Epoxy Encapsulation Removal 3 25 When all else fails, use X-ray to determine location of components or connections 2004 Grand Idea Studio, Inc.

Electrical Attacks 26 Surface Mount Devices Probing Boards Memory and Programmable Logic Chip Delidding and Die Analysis Emissions and Side-Channel Attacks Clock and Timing 2004 Grand Idea Studio, Inc.

Surface Mount Devices Harder to work with than through-hole devices – – Human hands have more resolution than the naked eye can resolve – 27 Ex.: Fine-pitched packages, tiny discrete components Don't get discouraged A microscope can go a long way to solder components Circuit Cellar, July 2004: Build your own computer-controlled, temperature-adjusting SMT oven 2004 Grand Idea Studio, Inc.

Surface Mount Devices 2 28 Easy to desolder using ChipQuik SMD Removal Kit (www.chipquik.com) 2004 Grand Idea Studio, Inc.

Probing Boards Look for test points and exposed traces/bus lines Surface mount leads and points are usually too small to manually probe Many ways to access: – – – – 29 Solder probe wire onto board using microscope Use an SMD micrograbber ( 5- 50) Use a probe adapter ( 100) from www.emulation.com, www.ironwoodelectronics.com, or www.advintcorp.com Build your own probe 2004 Grand Idea Studio, Inc.

Probing Boards 2 30 Ex.: Tap board used to intercept data transfer over Xbox's HyperTransport bus [4] 2004 Grand Idea Studio, Inc.

Memory and Programmable Logic Most memory is notoriously insecure – – Difficult to securely and totally erase data from RAM and non-volatile memory [6] – – 31 Not designed with security in mind Serial EEPROMs can be read in-circuit, usually SPI or I2C bus (serial clock and data) [5] Remnants may exist and be retrievable from devices long after power is removed Could be useful to obtain program code, temporary data, crypto keys, etc. 2004 Grand Idea Studio, Inc.

Memory and Programmable Logic 2 SRAM-based FPGAs most vulnerable to attack – – To determine PLD functionality, try an I/O scan attack – 32 Must load configuration from external memory Bit stream can be monitored to retrieve entire configuration Cycle through all possible combinations of inputs to determine outputs 2004 Grand Idea Studio, Inc.

Memory and Programmable Logic 3 Security fuses and boot-block protection – – – – 33 Enabled for "write-once" access to a memory area or to prevent full read back Usually implemented in any decent design Might be bypassed with die analysis attacks (FIB) or electrical faults [7] Ex.: PIC16C84 attack in which security bit is removed by increasing VCC during repeated write accesses 2004 Grand Idea Studio, Inc.

Chip Decapping and Die Analysis Analysis of Integrated Circuit (IC) dies is typically the most difficult area for hardware hacking With access to the IC die, you can: – – 34 Retrieve contents of Flash, ROM, FPGAs, other nonvolatile devices (firmware and crypto keys stored here) Modify or destroy gates and other silicon structures (e.g., reconnect a security fuse that prevents reading of the device) 2004 Grand Idea Studio, Inc.

Chip Decapping and Die Analysis 2 The good thing is that IC designers make mistakes, so tools are needed – – What tools? – – – – 35 Failure analysis Chip repair and inspection Chip Decappers Scanning Electron Microscope (SEM) Voltage Contrast Microscopy Focused Ion Beam (FIB) 2004 Grand Idea Studio, Inc.

Chip Decapping and Die Analysis 3 Equipment available on the used/surplus market Access to tools in most any large academic institution Reverse engineering and analysis services exist (still high priced, 10k- 20k) – – 36 Can provide functional investigation, extraction, IC simulation, analyze semiconductor processes, etc. Ex.: Semiconductor Insights (www.semiconductor.com) and Chipworks (www.chipworks.com) 2004 Grand Idea Studio, Inc.

Chip Decapping and Die Analysis: IC Decapsulation 37 Decapsulation tools used to "delid" or "decap" the top of the IC housing Uses chemical or mechanical means (or both) Will keep the silicon die intact while removing the outer material Ex.: Nippon Scientific (www.nscnet.co.jp/e), Nisene Technology Group (www.nisene.com), ULTRA TEC Manufacturing (www.ultratecusa. com), approx. 30k new, 15k used 2004 Grand Idea Studio, Inc.

Chip Decapping and Die Analysis: Scanning Electron Microscope 38 Used to perform sub-micron inspection of the physical die Metal or other material layers might need to be de-processed before access to gate structures Depending on ROM size and properties, can visually recreate contents (Photos from ADSR Ltd. and FIB International) 2004 Grand Idea Studio, Inc.

Chip Decapping and Die Analysis: Voltage Contrast Microscopy Detect variances of voltages and display them as contrast images – Performed with a SEM Ex.: Could extract information from a Flash ROM storage cell (Photo from http://testequipmentcanada.com/VoltageContrastPaper.html) 39 2004 Grand Idea Studio, Inc.

Chip Decapping and Die Analysis: Focused Ion Beams Send a focused stream of ions onto the surface of the chip – Cutting – Ex.: Cut a bond pad or trace from the die ( 1k- 10k) Deposition – 40 Beam current and optional use of gas/vapor changes the function Ex.: Add a jumper/reconnect a trace on the die ( 1k 10k) 2004 Grand Idea Studio, Inc.

Chip Decapping and Die Analysis: Focused Ion Beams 2 Imaging – 41 High-resolution image of die structure Ex.: Fibics Incorporated (www.fibics.com) or FIB International (www.fibinternational.com) (Photos from Fibics Incorporated) 2004 Grand Idea Studio, Inc.

Chip Decapping and Die Analysis: Focused Ion Beams 3 42 (Photos from Fibics Incorporated) 2004 Grand Idea Studio, Inc.

Emissions and Side-Channel Attacks All devices leak information – – – Can be monitored and used by attacker to determine secret information Devices may also be susceptible to RF or ESD (immunity) – 43 EMI (electromagnetic interference) from circuits (TEMPEST) [8, 9] Power supply fluctuations Visible radiation from LEDs and monitors [10, 11] Intentionally injected to cause failure 2004 Grand Idea Studio, Inc.

Emissions and Side-Channel Attacks: Power Supply Simple Power Analysis (SPA) – – – Differential Power Analysis (DPA) [12] – 44 Attacker directly observes power consumption Varies based on microprocessor operation Easy to identify intensive functions (cryptographic) Advanced mathematical methods to determine secret information on a device 2004 Grand Idea Studio, Inc.

Clock and Timing Attacks rely on changing or measuring timing characteristics of the system Active (Invasive) timing attacks – Passive timing attacks – – 45 Vary clock (speed up or slow down) to induce failure or unintended operation Non-invasive measurements of computation time Different tasks take different amounts of time 2004 Grand Idea Studio, Inc.

Security Through Obscurity "Security through obscurity" does not work – – Weak tactics to look out for when hacking "secure" hardware products: – – – – 46 Provides a false sense of security to designers/users Might temporarily discourage an attacker, but it only takes one to discover it Encoded forms of fixed data Scrambled address lines through extra logic Intentionally messy/lousy code Spurious and meaningless data ("signal decoys") 2004 Grand Idea Studio, Inc.

Hardware Hacking Challenges Advances in chip packaging – – – Highly-integrated chips (sub-micron) – Difficult, but not impossible, to probe and modify High speed boards – – 47 Ultra-fine pitch and chip-scale packaging (e.g., BGA, COB, CIB) Not as easy to access pins/connections to probe Discrete components can now easily be inhaled Processor and memory bus hundreds of MHz Serial bus speeds approaching Gigabit/sec. 2004 Grand Idea Studio, Inc.

Hardware Hacking Challenges 2 Cost of equipment – – Societal pressures – 48 Advanced tools still beyond the reach of average hobbyist (probing, decapping, SEMs, etc.) "State of the art" defined by what hackers can find in the trash and at swapmeets Hardware hacking is practically mainstream, but "hacker" is still a naughty word 2004 Grand Idea Studio, Inc.

Conclusions Hardware hacking is approaching a mainstream activity Plays an important role in the balance between consumers and corporations (e.g., The Man) Think as a designer would Nothing is ever 100% secure – 49 Given enough time, resources, and motivation, you can break anything The possibilities are endless Have fun! 2004 Grand Idea Studio, Inc.

References 1. 2. 3. 4. 5. 6. 50 J. Grand, et al, "Hack Proofing Your Network: 2nd Edition," Syngress Publishing, 2002, www.grandideastudio.com/files/books/hpyn2e chapter14.pdf J. Grand (Kingpin), “Palm OS Password Lockout Bypass,” March 2001, www.grandideastudio.com/files/security/mobile/ palm backdoor debug advisory.txt S.H. Weingart, "Physical Security Devices for Computer Subsystems: A Survey of Attacks and Defenses,'' Workshop on Cryptographic Hardware and Embedded Systems, 2000. A. Huang, "Hacking the Xbox: An Introduction to Reverse Engineering," No Starch Press, 2003. J. Grand (Kingpin), "Attacks on and Countermeasures for USB Hardware Token Devices,'' Proceedings of the Fifth Nordic Workshop on Secure IT Systems, 2000, www.grandideastudio.com/files/security/tokens/usb hardware token.pdf P. Gutmann, "Secure Deletion from Magnetic and Solid-State Memory Devices," Sixth USENIX Security Symposium, 1996, www.usenix.org/publications/ library/proceedings/sec96/full papers/gutmann/index.html 2004 Grand Idea Studio, Inc.

References 2 7. 8. 9. 10. 11. 12. 51 S. Skorobogatov, "Breaking Copy Protection in Microcontrollers," www.cl.cam.ac.uk/ sps32/mcu lock.html W. van Eck, “Electronic Radiation from Video Display Units: An Eavesdropping Risk?” Computers and Security, 1985, www.jya.com/emr.pdf J.R. Rao and P. Rohatgi, "EMPowering Side-Channel Attacks," IBM Research Center, www.research.ibm.com/intsec/emf-paper.ps Joe Loughry and D.A. Umphress, "Information Leakage from Optical Emanations," ACM Transactions on Information and System Security v.5, #3, August 2002, www.applied-math.org/optical tempest.pdf M. Kuhn, "Optical Time-Domain Eavesdropping Risks of CRT Displays," Proceedings of the 2002 IEEE Symposium on Security and Privacy, May 2002, www.cl.cam.ac.uk/ mgk25/ieee02-optical.pdf P. Kocher, J. Jaffe, and B. Jun, "Overview of Differential Power Analysis," www.cryptography.com/resources/whitepapers/DPATechInfo.PDF 2004 Grand Idea Studio, Inc.

Appendix A: Additional Resources J. Grand, et al, "Hardware Hacking: Have Fun While Voiding Your Warranty," Syngress Publishing, January 2004. J. Grand, "Practical Secure Hardware Design for Embedded Systems," Proceedings of the 2004 Embedded Systems Conference, 2004, www.grandideastudio.com/ files/security/hardware/practical secure hardware design.pdf A. Huang, "Keeping Secrets in Hardware: the Microsoft XBox Case Study," Massachusetts Institute of Technology AI Memo 2002-008, May 2002, http://web.mit.edu/bunnie/www/proj/anatak/AIM-2002-008.pdf F. Beck, "Integrated Circuit Failure Analysis - A Guide to Preparation Techniques," John Wiley & Sons, 1998. O. Kömmerling and M. Kuhn, "Design Principles for Tamper-Resistant Smartcard Processors," USENIX Workshop on Smartcard Technology, 1999, www.cl.cam. ac.uk/ mgk25/sc99tamper.pdf R.G. Johnston and A.R.E. Garcia, "Vulnerability Assessment of Security Seals", Journal of Security Administration, 1997, www.securitymanagement.com/ library/lanl 00418796.pdf 52 2004 Grand Idea Studio, Inc.

Appendix B: Related Web Sites Cambridge University Security Group - TAMPER Laboratory, www.cl.cam.ac.uk/Research/Security/tamper Molecular Expressions: Chip Shots Gallery, http://microscopy.fsu.edu/chipshots/index.html Bill Miller's CircuitBending.com, http://billtmiller.com/circuitbending Virtual-Hideout.Net, www.virtual-hideout.net LinuxDevices.com - The Embedded Linux Portal, www.linuxdevices.com Roomba Community - Discussing and Dissecting the Roomba, www.roombacommunity.com TiVo Techies, www.tivotechies.com 53 2004 Grand Idea Studio, Inc.

Appendix C: Tools of the Warranty Voiding Trade 54 Bright overhead lighting or desk lamp Protective gear (mask, goggles, rubber gloves, smock, etc.) ESD protection (anti-static mat and wriststrap) Screwdrivers X-ACTO hobby knife Dremel tool Needle file set 2004 Grand Idea Studio, Inc.

Appendix C: Tools of the Warranty Voiding Trade 2 55 Wire brushes Sandpaper Glue Tape Cleaning supplies Variable-speed cordless drill w/ drill bits Heat gun and heat-shrink tubing Center punch 2004 Grand Idea Studio, Inc.

Appendix C: Tools of the Warranty Voiding Trade 3 56 Nibbling tool Jigsaw Wire stripper/clipper Needle-nose pliers Tweezers Soldering iron w/ accessories (solder sucker, various tips, etc.) Basic electronic components 2004 Grand Idea Studio, Inc.

Appendix C: Tools of the Warranty Voiding Trade 4 57 Microscope Digital and analog multimeters Adjustable power supply Device programmer UV EPROM eraser PCB etching kit Oscilloscope Logic Analyzer 2004 Grand Idea Studio, Inc.

Appendix D: Where to Obtain the Tools 58 The Home Depot (www.homedepot.com) Lowe's (www.lowes.com) Hobby Lobby (www.hobbylobby.com) McMaster-Carr (www.mcmaster.com) Radio Shack (www.radioshack.com) Digi-Key (www.digikey.com) Contact East (www.contacteast.com) Test Equity (www.testequity.com) 2004 Grand Idea Studio, Inc.

Thanks! Joe Grand (Kingpin) [email protected]