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Tutorial B5 Breaking AES (Straightforward)

1,259 bytes removed, 16:35, 9 October 2018
Flashing Firmware
{{Warningbox|This tutorial will take has been updated for ChipWhisperer 4.0.0 release. If you through a complete attack on a software AES implementationare using 3.x. The specific implementation being attacked is a well-known AES implementation written x see the "V3" link in C, which is likely to be similar to other implementations used by proprietary systemsthe sidebar.}}
{{Infobox tutorial
|name = B5: Breaking AES (Straightforward)
|image =
|caption =
|software versions =
|capture hardware = CW-Lite, CW-Lite 2-Part, CW-Pro
|Target Device =
|Target Architecture = XMEGA/ARM
|Hardware Crypto = No
|Purchase Hardware =
}}
This tutorial will take you through a complete attack on a software AES implementation. The specific implementation being attacked is a well-known AES implementation written in C, which is likely to be similar to other implementations used by proprietary systems. == Capturing ==
This tutorial runs on four different hardware targets. You only need to follow the steps for your given hardware.
=== Capturing with ChipWhisperer-Lite /Pro with default XMEGA Target (CW1173 + CW303) === WARNING: This video was recorded with API V3.x, some changes happened so please take note.
NOTE: You can see a Quick-Start Guide and Video for this target on the [[CW1173_ChipWhisperer-Lite]] page:
=== Hardware Setup ===
<ol style="list-style-type: decimal;">{{CollapsibleSection<li><p>Connect the |intro = ==== CW1173 by micro USB cable to computer.</p>(Lite) Hardware Setup ====<blockquote><p>[[File:cw1173_microusb.jpg|image]]</p></blockquote></li></ol>content= CWLite HW Setup}}
{{CollapsibleSection|intro === Capturing the Traces ==CW1200 (Pro) Hardware Setup ====|content= CW1200 HW Setup}}
<ol style{{CollapsibleSection|intro ="list-style-type: decimal;"><li>Close &amp; reopen the capture software ==== CW308 (to clear out any previous connection which may be invalidUFO).</li>Hardware Setup ====<li><p>From the ''Project'' menu elect the ''Example Scripts'' and then ''ChipWhisperer-Lite: AES SimpleSerial on XMEGA'' (make sure you don't select the &quot;SPA&quot; example):</p><p>[[File:runscript_cw1173xmega.png|image]]</p></li><li><p>The script will automatically connect to the capture hardware and run 2 example traces. You should see something that looks like the following screen:</p><p>[[File:capture_cw1173xmega.png|image]]</p><p>To complete the tutorial, follow these steps:</p><blockquote><ol stylecontent="list-style-type: decimal;"><li>Switch to the ''General Settings'' tab</li><li>If you wish to change the number of traces, do so here. The default of 50 should be sufficient to break AES though!</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>You'll see the trace count in the status bar. Once it says ''Trace 50 done'' (assuming you requested 50 traces) the capture process 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><li>Skip ahead to [[#Analyzing_the_Traces]].</li></ol>CW308 HW Setup}}
== Capturing with ChipWhisperer= Building Firmware ===Note that for this tutorial, you'll need to use the <code>simpleserial-Lite aes</code> firmware.{{CollapsibleSection|intro = ==== Building for CWLite with NOTDuino (CW1173 + CW304) XMEGA Target ====|content=Building for XMEGA}}
{{CollapsibleSection|intro === Hardware Setup ==Building for CWLite with Arm Target ====|content= Building for Arm}}
<ol style="list-style-type: decimal;">{{CollapsibleSection<li>Set jumpers on NOTDuino to default position (see silkscreen on bottom of NOTDuino |intro = ==== Building for default positions).</li>Other Targets ====<li>Connect the NOTDuino using the SMA cable on the &quot;measure&quot; port, and the 20-pin IDC cable:</li><li><p>Connect the CW1173 by micro USB cable to computer.</p><p>[[File:cw1173_avr_microusb.jpg|image]]</p></li></ol>content= Building for Other Targets}}
=== Capturing Flashing Firmware ===Note that for this tutorial, you'll need to use the Traces <code>simpleserial-aes</code> firmware. We won't be modifying the firmware, so feel free to just build in the <code>simpleserial-aes</code> folder.{{CollapsibleSection|intro = ==== Programming the XMEGA Target ====|content=Programming XMEGA}}
<ol style{{CollapsibleSection|intro ="list-style-type: decimal;"><li>Close &amp; reopen ==== Programming the capture software STM32F3 (to clear out any previous connection which may be invalidCW303 Arm).</li>Target ====<li><p>From the ''Project'' menu elect the ''Example Scripts'' and then ''ChipWhisperer-Lite: AES SimpleSerial on ATMega328P''</p><p>[[File:runscript_cw1173avr.png|image]]</p></li><li><p>The script will automatically connect to the capture hardware and run 2 example traces. You should see something that looks like the following screen:</p><p>[[File:capture.png|image]]</p><p>To complete the tutorial, follow these steps:</p><blockquote><ol stylecontent="list-style-type: decimal;"><li>Switch to the ''General Settings'' tab</li><li>If you wish to change the number of traces, do so here. The default of 50 should be sufficient to break AES though!</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>You'll see the trace count in the status bar. Once it says ''Trace 50 done'' (assuming you requested 50 traces) the capture process 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><li>Skip ahead to [[#Analyzing_the_Traces]].</li></ol>Programming Arm}}
{{CollapsibleSection
|intro = ==== Programming Other Targets ====
|content= Programming Other}}
=== Capturing with Capture Rev2 + Multi-Target (CW1002 + CW301) the Traces ===
=== Hardware Setup ===[[File:cwsetup_scriptselection.png|889x889px]]
This tutorial uses # Switch to the [[CW1002_ChipWhisperer_Capture_Rev2]] hardware along with the [[CW301_Multi-Target]] board. Note that you '''don't need hardware'Python Console'' tab.# The script selection window (2) lists available example scripts. Scroll down to complete the tutorial"connect_cwlite_simpleserial. Instead you can download [https://wwwpy" and click on it.assembla# You will see the script contents appear in the "Script Preview" window (3).com/spaces/chipwhisperer/wiki/Example_Captures example traces from You can either hit the ChipWhisperer Site]"Run" button or double-click the filename of the script to execute it. Do either of those now.
This example uses the Atmel AVR in 28-pin DIP programmed with a ''simpleserial'' communications protocol. This is the default firmware programmed into the devices, so you shouldn't need The window should change to do anything. If you've erased the device, you can see programming instructions in indicate the [[Installing_ChipWhisperer]] section.connect succeeded:
The Multi-Target board should be plugged into the ChipWhisperer Capture Rev2 via the 20-pin target cable[[File:cwsetup_scriptselection_cwliterun. The ''VOUT'' SMA connector is wired to the ''LNA'' input on the ChipWhisperer-Capture Rev2 front panel. The general hardware setup is as follows:png|889x889px]]
<blockquotep>[[File<ol start="4" style="list-style-type:hwdecimal;"><li>The console lists the exact script that is executed. Note you could have manually executed the script commands line-1by-line in this console.</li><li>The "Scope" and "Target" buttons will show as connected.</li><li>The Status Bar will show a connection.</li></ol></p>Note in previous software versions, this tutorial took you through manual setup. This can still be done (using the GUI), but instead now the API has been made more powerful, so the example configuration script will be used instead.jpg|image]]
# 20-Pin Header connects Multi-Target to Capture Hardware# VOUT Connects to SMA Cable# SMA Cable connects to To do so, simply scroll down and select the "setup_cwlite_xmega_aes.py" if you'LNAre using the CW303 XMEGA target. If you' on CHA input# USB-Mini connects to side (NB: Confirm jumper settings in next section first)</blockquote>Jumpers on re using the Multi-Target Victim board are as follows:CW303 Arm target, select "setup_cwlite_stm32f_aes.py".
<blockquote>[[File:hw-2If you're using another target, use the setup script for that target (such as setup_cw308_esp32.py). Additionally, try capturing a trace and seeing how long the "Trigger Active Count" field is under trigger setup. This will set an upper bound on how big "Total Samples" should be (since the AES is completed by this point). Reducing "Total Samples" will give better correlation and take less time to capture and analyze, but lowering it too much will miss the operations we're interest in! If your target lacks a script, "setup_cwlite_stm32f_aes.py" will probably work, but you should check the wiki page for your target to make sure there aren't any differences.jpg|600px|image]]
# NO jumpers mounted in XMEGA Portion or SmartCard Portion (JP10-JP15, JP19, JP7-JP8, JP17)# 3.3V IO Level (JP20 set to INT.)# The 7.37 MHz oscillator is selected as the CLKOSC source (JP18)# The CLKOSC is connected to the AVR CLock Network, along with connected to the FPGAIN pin (JP4)# The TXD &amp; RXD jumpers are set (JP5, JP6)# Power measurement taken from VCC shunt (JP1)# The TRIG jumper is set (JP28) (NOTE[[File: Early revisions of the multi-target board do not have the TRIG jumper and you can ingore this)cwsetup_scriptselection_xmegaconfig_cwliterun.png|718x718px]]
For more information on these jumper settings see [[CW301_Multi-TargetFile:Stm32f aes.PNG|frameless|798x798px]] .</blockquote>=== Setting up the Software ===
It is assumed that you've already followed the guide in [[Installing_ChipWhisperer]]. Thus it is assumed you are able to communicate with the ChipWhisperer Capture Rev2 hardware. Note in particular you must have configured the FPGA bitstream in the ChipWhisperer-Capture software, all part of the description in the [[Installing_ChipWhisperer]] guide. === Capturing the Traces === This tutorial uses a simple script that ships with the ChipWhisperer Capture software. The easiest method of accomplishing the trace capture is as follows: <ol style="list-style-type: decimal;"><li>Close &amp; reopen the capture software (to clear out any previous connection which may be invalid).</li><li><p>From the ''Project'' menu elect 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. You should see something that looks like the following screen:</p><p>[[File:capture.png|image]]</p><p>To complete the tutorial, follow these steps:</p><blockquote><ol start="7" style="list-style-type: decimal;">
<li>Switch to the ''General Settings'' tab</li>
<li>If you wish to change the number of traces, do so here. The default of 50 should be sufficient to break AES for most targets though!</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>You'll see the trace count in the status bar. Once it says ''Trace 50 done'' (assuming you requested 50 traces) the capture process 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>
<li>Skip ahead to [[#Analyzing_the_Traces]].</li></ol>
== Analyzing the Traces ==
== Capturing with PicoScope + Multi-Target (CW301) == Opening File &lt;TODO&gt; Viewing Traces == Analyzing the Traces =
<ol style="list-style-type: decimal;">
<li>Open the Analyzer software</li>
<li>From the ''File --> Open Project'' option, navigate to the .cwp file you save previously. Open this file.</li>
<li><p>Select Switch to the ''Project --> Manage TracesTrace Output Plot'' option to open tab on the dialog, enable the captured traces by adding a check-mark in the boxright side. Close </li><li>Switch to the dialog with `ESC`:''Results'' setting tab on the left side</pli><li>Scroll down to the ''Trace Output Plot'' setting, highlighted below:<p>[[File:tracemanagev4_tracedraw.png|image500px]]</p></li><li>You can choose to plot a specific range of traces. For example type '''0-10''' in the ''Trace(s) to plot'' window.<p/li>If <li>Hit the ''Redraw'' button when you wish change the trace plot range.</li><li>You can right-click on the waveform to view change options, or left-click and drag to zoom.</li><li>Use the toolbar to quickly reset the zoom back to original.</li><li>Try more advanced plotting options, like '''0(r),4-7(b)''' to plot trace data0 in red, follow these steps:and 4-6 in blue. See a full list of possible commands on the page [[Plotting_Widget]].</pli></ol>
<ol style="list-style-type: decimal;">== Running Attack Script ===<li>Switch In ChipWhisperer V4.0, we now use attack scripts for everything. As in the capture program, switch to the ''Waveform Display'Python Console' tab</li><li>Switch to the ''General'' parameter setting tab</li><li>You can choose to plot a specific range of traces</li><li>Hit & find the ''Redraw'' button when attack scripts. There may be additional scripts there, but you change should find one called "attack_cpa.py". It has the trace plot range</li>following contents: <lisyntaxhighlight lang=python>You can right-click on the waveform to change optionsimport chipwhisperer as cwfrom chipwhisperer.analyzer.attacks.cpa import CPAfrom chipwhisperer.analyzer.attacks.cpa_algorithms.progressive import CPAProgressivefrom chipwhisperer.analyzer.attacks.models.AES128_8bit import AES128_8bit, or leftSBox_outputfrom chipwhisperer.analyzer.preprocessing.add_noise_random import AddNoiseRandom #self.project = cw.openProject("2017-click and drag to zoom</li>mar23-xmega-aes.cwp")<li>traces = self.project.traceManager(oops there is no 6)</li><li>Use the toolbar #Example: If you wanted to quickly reset add noise, turn the zoom back .enabled to original</li>"True"self.ppmod[0] = AddNoiseRandom()self.ppmod[0].noise = 0.05self.ppmod[0].enabled = False attack = CPA()leak_model = AES128_8bit(SBox_output)attack.setAnalysisAlgorithm(CPAProgressive, leak_model) attack.setTraceStart(0)attack.setTracesPerAttack(50)attack.setIterations(1)attack.setReportingInterval(10)attack.setTargetSubkeys([0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15])attack.setTraceSource(self.ppmod[0])attack.setPointRange((0, 3000)) self.results_table.setAnalysisSource(attack)self.correlation_plot.setAnalysisSource(attack)self.output_plot.setAnalysisSource(attack)self.pge_plot.setAnalysisSource(attack)attack.processTraces()</olsyntaxhighlight>
<p>[[File:traceplotting.png|image]]</p></li><li><p>You can view or change the attack options on the ''Attack'' parameter settings tabsee this script has several sections:</p><ol style="list-style-type: decimal;"><li>The ''Hardware Model'' settings are correct for the software AES by default</li><li>The ''Point Setup'' makes the attack faster by looking over a more narrow range of points. Often you might have to characterize your device to determine the location of specific attack points of interest.</li><li>''Traces per Attack'' allows you to use only a subset of capture traces on each attack. Or if you have for example 1000 traces, you could average the results of attacking 50 traces over 200 attack runs.</li><li>''Reporting Interval'' is how often data is generated. A smaller interval generates more useful output data, but greatly increases computational complexity (e.g. slows down attack). If you only care about attacking the system, the reporting interval can be set to the number of traces. In which case the attack runs completely, and you get the results. For this tutorial you can set to a smaller number (such as 5).</li></ol>
<p# Imports for needed functions.# Loading of project (if using a project from disk) & setting of trace information.# Configuration of attack.# Connecting output (drawing) widgets to the attack.# Running the attack. If you need to modify the script, you can edit the file in an external editor. You will need to ensure your system is configured to open your preferred editor on ".py" files, OR configure the editor under ''Help -->[[File:attacksettingsPreferences''.png|image]] The default options should work, but you can modify for example the ''Reporting Interval'' to see more detailed graphs. </p></liol style="list-style-type: decimal;"><li><p>Finally run the attack by switching to the ''Results Table'' tab and then hitting the ''AttackRun'' buttonwith the script selected:</p><p>[[File:attackv4_runscript.png|image400px]]</p></li>
<li><p>If you adjusted the ''Reporting Interval'' to a smaller number such as 5, you'll see the progression of attack results as more traces are used. If not you should simply see the final results, which should have the correct key highlighted in red. In the following case the correct key ''was'' recovered:</p>
<p>[[File:attack-done.png|image]]</p></li>
<p>[[File:attack-done2.png|image]]</p></li></ol>
== Next Steps == This has only briefly outlined how to perform a CPA attack. You can move onto more advanced tutorials, especially showing you how the actual attack works when performed manually. This tutorial also utilized tiny-AES128-C for Arm targets, which uses the same operations as the XMEGA target. For a more typical 32 bit AES attack, see [[Tutorial A8 32bit AES]].
This has only briefly outlined how to perform a CPA attack. You can move onto more advanced tutorials, especially showing you how the actual attack works when performed manually.== Links ==
{{Template:Tutorials}}[[Category:Tutorials]]
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