Changes

This tutorial uses can use either the [[CW1173_ChipWhisperer-Lite]], [[CW1200_ChipWhisperer-Pro]], or [[CW1002_ChipWhisperer_Capture_Rev2]] hardware along with the [[CW301_Multi-Target]] board. Note that you '''don't need hardware''' to complete the tutorial. Instead you can download [https://www.assembla.com/spaces/chipwhisperer/wiki/Example_Captures example traces from the ChipWhisperer Site], just look for the traces titled ''XMEGA: AES128 Hardware Accelerator (ChipWhisperer Tutorial #A6)''. '''NOTE: The ChipWhisperer-Lite Target Board contains an XMEGA device, but this device DOES NOT contain the hardware crypto engine. Only the CW301 Multi-Target board contains an XMEGA with a hardware AES engine.'''

The Multi-Target board should be plugged into the ChipWhisperer Capture Rev2 via the 20-pin target cable. The ''VOUT'' SMA connector is wired to the ''LNA'' input on the ChipWhisperer-Capture Rev2 front panel. The general hardware setup is as followsslightly different for the ChipWhisperer-Lite/Pro and older Capture-Rev2:

<blockquote>=== Using ChipWhisperer-Lite / ChipWhisperer-Pro === # 20-Pin Header connects Multi-Target to Capture Hardware# VOUT Connects to SMA Cable# SMA Cable connects to 'LNA' on CHA input Jumpers on the Multi-Target Victim board are as follows: [[File:xmegajumpers_cwlite.jpg]] # NO jumpers mounted in AVR Portion (JP1,JP4-6,JP28) or SmartCard Portion. Note if your multi-target board does not have JP28, the TRIG jumper for the AVR, you will have to remove the AVR from the socket.# 3.3V IO Level (JP20 set to INT.)# FPGAOUT is routed to XTAL1 pin of XMEGA (requires jumper wire to JP4/JP15).# The 7.37 MHz oscillator is not connected (JP18)# The TXD &amp; RXD jumpers are set on the XMEGA portion (JP5, JP6)# The TRIG jumper is set on the XMEGA portion (JP13)# The PWR jumper is set on the XMEGA portion (JP14)# Power measurement taken from VCC shunt (JP12) === Using Capture Rev 2 === # 20-Pin Header connects Multi-Target to Capture Hardware

<blockquote>[[File:xmegajumpers.jpg|image]]

Device: atxmega128a3atxmega16a4

Using either AVRStudio or AVRDudethe XMEGA Programmer, program the XMega16A4 device (it is connected to the programmer built into the ChipWhisperer) with the resulting simpleserial.hex file.

=== Running the Capture Capturing Traces ===

<ol style="list=== CW-styleCapture Lite/Pro Specific Setup ====  The following are specific instructions only for the ChipWhisperer-typeLite or -Pro: decimal;"><li>Close # From the Project menu select the Example Scripts and then ChipWhisperer-Lite: AES SimpleSerial on XMEGA# This should connect to the target board &amp; reopen run a few encryptions. You should check the capture software "Encryption Status Manager" along with viewing the resulting power measurement.# Jump to the generic instructions (to clear out any previous connection which may be invalidskip the CWC-Rev2 instructions next).</li><li><p>==== CW-Capture Rev2 Specific Setup ==== The following are specific instructions only for the ChipWhisperer-Capture Rev 2: #From the ''Project'' menu elect select the ''Example Scripts'' and then ''ChipWhisperer-Rev2: SimpleSerial Target''</p><p>#: [[File:runscript.png|image]]</p></li><li><p>#The script will automatically connect to the capture hardware and run 2 example traces. They will not yet work on the XMega as additional setup is required. You must switch the RX/TX pins:</p><p>#:[[File:xmegarxtx.png|image]]</p></li><li><p>#Run a 'Capture 1', you should confirm the encryption algorithm is working:</p><p>#:[[File:capture1_working.png|image]]</p></li><li><p>#Jump to the generic capture instructions (next) ==== Trace Capture Instructions ==== #Switch from software to hardware crypto. To do this change the 'Goyou' command ll have to change the <code>h$TEXT$\nmakefile</code>for the project.#:In the makefile, add a define for </pcode>HWCRYPTO=1<p/code>[[File:gocommand.png|image]]</ppre>#Multi-Target Board, XMEGA DevicePLATFORM = CW301_XMEGA#Optional - use hardware cryptoCDEFS += -DHWCRYPTO=1</lipre><li><p>#Build a new hex-file, and program the file in.#Run a few 'capture 1' traces, and confirm (using the Encryption Status Manager) that the encryption was successful.#Finally, set the offset to 1500, and number of samples to only 1000:</p><p>#:[[File:slength.png|image]]</p></li><li><p>#Confirm you now get something like this with a 'capture 1':</p><p>#:[[File:capture1_fullworking.png|image]]</p></li><li><p>To complete the tutorial, follow these steps:</p><blockquote><ol style="list-style-type: decimal;"><li>#Switch to the ''General Settings'' tab</li><li>#Change the number of traces to 3000.</li><li>#Hit the ''Capture Many'' button (M in a green triangle) to start the capture process.</li><li>#You will see each new trace plotted in the waveform display.</li><li>#Wait until the capture is complete.</li></ol></blockquote></li><li>#Finally save this project using the ''File --&gt; Save Project'' option, give it any name you want.</li></ol>

<dt>The API calling parameters changed in release 0.10 a number of the ChipWhisperer softwaretimes. If using version 0.09 release 10 or older, either see the documentation that</dt><dd><p>is present in the 'doc' directory (which will always correspond to your release), or see Appendix B -2/B-1 for the full attack script.</p></dd></dl>

return self.attack</pre></li>

== Appendix A: Full Attack Script for Current Release ==

<pre># Based on Ilya Kizhvatov's work, published as &quot;Side Channel Analysis of AVR XMEGA Crypto Engine&quot;from chipwhisperer.common.api.CWCoreAPI import CWCoreAPIfrom chipwhisperer.common.scripts.base import UserScriptBase# Imports from Preprocessingimport chipwhisperer.analyzer.preprocessing as preprocessing# Imports from Attackfrom chipwhisperer.analyzer.attacks.cpa import CPAfrom chipwhisperer.analyzer.attacks.cpa_algorithms.progressive import CPAProgressiveimport chipwhisperer.analyzer.attacks.models.AES128_8bit# Imports from utilListfrom chipwhisperer.analyzer.attacks.models.AES128_8bit import getHW class AESXMega(object): numSubKeys = 16  @staticmethod def leakage(pt, ct, guess, bnum, setting, state): #In real life would recover this one at a time, in our case we know entire full key, so we cheat to make #the iterations easier knownkey = [0x2b, 0x7e, 0x15, 0x16, 0x28, 0xae, 0xd2, 0xa6, 0xab, 0xf7, 0x15, 0x88, 0x09, 0xcf, 0x4f, 0x3c]  s1 = pt[bnum-1] ^ knownkey[bnum-1] s2 = pt[bnum] ^ guess  #We subtract 8 as way measurements are taken a higher current results in a lower voltage. Normally this #doesn't matter due to use of absolute values. In this attack we do not use absolute mode, so we simply #"flip" the expected hamming weight, which results in the correlation changing signs. return 8-getHW(s1 ^ s2) class UserScript(UserScriptBase): name = "Auto-generated" description = "Auto-generated Attack Script" def __init__(self, api): UserScriptBase.__init__(self, api) self.initProject() self.initPreprocessing() self.initAnalysis() self.initReporting()  def initProject(self): pass  def initPreprocessing(self): self.traces = self.api.project().traceManager()  def initAnalysis(self): self.attack = CPA() self.attack.setTraceSource(self.traces, blockSignal=True) self.attack.setAnalysisAlgorithm(CPAProgressive,AESXMega,None) self.attack.setTraceStart(0) self.attack.setTracesPerAttack(3000) self.attack.setIterations(1) self.attack.setReportingInterval(50) self.attack.setTargetBytes([1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15]) self.attack.setPointRange((0,995)) self.attack.setAbsoluteMode(False)  def initReporting(self): # Configures the attack observers (usually a set of GUI widgets) self.api.getResults("Attack Settings").setAnalysisSource(self.attack) self.api.getResults("Correlation vs Traces in Attack").setAnalysisSource(self.attack) self.api.getResults("Output vs Point Plot").setAnalysisSource(self.attack) self.api.getResults("PGE vs Trace Plot").setAnalysisSource(self.attack) self.api.getResults("Results Table").setAnalysisSource(self.attack) self.api.getResults("Save to Files").setAnalysisSource(self.attack) self.api.getResults("Trace Output Plot").setTraceSource(self.traces) self.api.getResults("Trace Recorder").setTraceSource(self.traces)  def run(self): self.attack.processTraces() if __name__ == '__main__': import chipwhisperer.analyzer.ui.CWAnalyzerGUI as cwa from chipwhisperer.common.utils.parameter import Parameter Parameter.usePyQtGraph = True # Comment if you don't need the GUI api = CWCoreAPI() # Instantiate the API app = cwa.makeApplication("Analyzer") # Comment if you don't need the GUI gui = cwa.CWAnalyzerGUI(api) # Comment if you don't need the GUI gui.show() # Comment if you don't need the GUI api.runScriptClass(UserScript) # Run UserScript through the API app.exec_() # Comment if you don't need the GUI</pre> == Appendix B-1: Full Attack Script for older (< 3.1.x) == Here is the full attack script for current older releases:- '''DO NOT attempt to use with a current release (3.1.8 or later)'''.

== Appendix B-2: Full Attack Script for 0.09 or Older Releases == Here is the full attack scriptfor VERY old releases: