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Tutorial B5 Breaking AES (Straightforward)

2,748 bytes removed, 16:35, 9 October 2018
→‎Flashing Firmware
{{Warningbox|This tutorial has been updated for ChipWhisperer 4.0.0 release. If you are using 3.x.x see the "V3" link in the sidebar.}}
 
{{Infobox tutorial
|name = B5: Breaking AES (Straightforward)
|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 (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/CW1200 by USB cable to computer.</p>(Lite) Hardware Setup ====<blockquote><p>[[File:cw1173_microusb.jpg|image]]</p></blockquote></li><li> The software AES implementation that will run on the target is located in <code>chipwhisperer\hardware\victims\firmware\simpleserial-aes</code>. In a terminal window, navigate here and run the command <code>make</code> to build the firmware. content= CWLite HW Setup}}
As in previous tutorials, ensure that the firmware has been built for the correct board. Here, the output of <code>make</code> should end like{{CollapsibleSection<pre>|intro = ==== CW1200 (Pro) Hardware Setup ====AVR Memory Usage----------------Device: atxmega128d3|content= CW1200 HW Setup}}
Program: 3078 bytes {{CollapsibleSection|intro = ==== CW308 (2.2% FullUFO)Hardware Setup ====(.text + .data + .bootloader)|content= CW308 HW Setup}}
Data: 352 bytes (4=== Building Firmware ===Note that for this tutorial, you'll need to use the <code>simpleserial-aes</code> firmware.3% Full){{CollapsibleSection(.data + .bss + .noinit)|intro = ==== Building for CWLite with XMEGA Target ====|content= Building for XMEGA}}
{{CollapsibleSection
|intro = ==== Building for CWLite with Arm Target ====
|content= Building for Arm}}
Built {{CollapsibleSection|intro = ==== Building for platform CW-Lite XMEGAOther Targets ====|content= Building for Other Targets}}
=== Flashing Firmware ===Note that for this tutorial, you'll need to use the <code>simpleserial-aes</code> firmware. We won't be modifying the firmware, so feel free to just build in the <code>simpleserial------- end --------aes</precode>folder.{{CollapsibleSectionMake sure that |intro = ==== Programming the platform is correct.XMEGA Target ====</li>|content= Programming XMEGA}}
<li> Upload the firmware to the target chip. The process to do this is the same as the previous tutorials:{{CollapsibleSection* Open |intro = ==== Programming the ChipWhisperer Capture software.* Connect to the ChipWhisperer. STM32F3 (You can do this using a script or by filling out the generic settings and connecting to the board yourself.CW303 Arm)Target ====* Open the XMEGA Programmer (**Tools > ChipWhisperer-Lite XMEGA Programmer**).|content= Programming Arm}}* Find the hex file you compiled and program it onto the target.</li>{{CollapsibleSection|intro = ==== Programming Other Targets ====</ol>|content= Programming Other}}
=== Capturing the Traces ===
<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-Lite: AES SimpleSerial on XMEGA'' (make sure you don't select the &quot;SPA&quot; example):</p><p>[[File:runscript_cw1173xmegacwsetup_scriptselection.png|image889x889px]]</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 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 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>
== Capturing with ChipWhisperer-Lite/Pro with NOTDuino # Switch to the ''Python Console'' tab.# The script selection window (CW3042) ==lists available example scripts. Scroll down to "connect_cwlite_simpleserial.py" and click on it.# You will see the script contents appear in the "Script Preview" window (3). You can either hit the "Run" button or double-click the filename of the script to execute it. Do either of those now.
=== Hardware Setup ===The window should change to indicate the connect succeeded:
<ol style="list-style-type: decimal;"><li>Set jumpers on NOTDuino to default position (see silkscreen on bottom of NOTDuino for default positions).</li><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/CW1200 by USB cable to computer.</p><p>[[File:cw1173_avr_microusbcwsetup_scriptselection_cwliterun.jpgpng|image889x889px]]</p></li></ol>
<p><ol start="4" style== Capturing "list-style-type: decimal;"><li>The console lists the Traces ===exact script that is executed. Note you could have manually executed the script commands line-by-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. To do so, simply scroll down and select the "setup_cwlite_xmega_aes.py" if you're using the CW303 XMEGA target. If you're using the CW303 Arm target, select "setup_cwlite_stm32f_aes.py".
<ol style=If 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 "list-style-type: decimal;Trigger Active Count"><li>Close &amp; reopen field is under trigger setup. This will set an upper bound on how big "Total Samples" should be (since the capture software (to clear out any previous connection which may be invalidAES is completed by this point).</li><li><p>From 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''Project'' menu elect 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''Example Scripts'' and then ''ChipWhisperer-Lite: AES SimpleSerial on ATMega328P''</p>t any differences. <p>[[File:runscript_cw1173avrcwsetup_scriptselection_xmegaconfig_cwliterun.png|image718x718px]]</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:captureStm32f aes.pngPNG|imageframeless|798x798px]]</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 Capture Rev2 + Multi-Target (CW1002 + CW301) = Opening File & Viewing Traces ===
<ol style=== Hardware Setup ==="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>Switch to the ''Trace Output Plot'' tab on the right side.</li><li>Switch to the ''Results'' setting tab on the left side</li><li>Scroll down to the ''Trace Output Plot'' setting, highlighted below:<p>[[File:v4_tracedraw.png|500px]]</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.</li><li>Hit the ''Redraw'' button when you change the trace plot range.</li><li>You can right-click on the waveform to 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 0 in red, and 4-6 in blue. See a full list of possible commands on the page [[Plotting_Widget]].</li></ol>
This tutorial uses the [[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].=== Running Attack Script ===
This example uses In ChipWhisperer V4.0, we now use attack scripts for everything. As in the capture program, switch to the Atmel AVR in 28-pin DIP programmed with a ''simpleserial'Python Console' communications protocol. This is the default firmware programmed into the devices, so you shouldn't need to do anything. If you've erased tab & find the deviceattack scripts. There may be additional scripts there, but you can see programming instructions in should find one called "attack_cpa.py". It has the [[Installing_ChipWhisperer]] section.following contents:
The Multi-Target board should be plugged into the ChipWhisperer Capture Rev2 via the 20-pin target cable<syntaxhighlight lang=python>import chipwhisperer as cwfrom chipwhisperer. The ''VOUT'' SMA connector is wired to the ''LNA'' input on the ChipWhisperer-Capture Rev2 front panelanalyzer. The general hardware setup is as follows:attacks.cpa import CPAfrom chipwhisperer.analyzer.attacks.cpa_algorithms.progressive import CPAProgressivefrom chipwhisperer.analyzer.attacks.models.AES128_8bit import AES128_8bit, SBox_outputfrom chipwhisperer.analyzer.preprocessing.add_noise_random import AddNoiseRandom
<blockquote>[[File:hw#self.project = cw.openProject("2017-1mar23-xmega-aes.cwp")traces = self.project.jpg|image]]traceManager()
# 20-Pin Header connects Multi-Target Example: If you wanted to Capture Hardware# VOUT Connects add noise, turn the .enabled to SMA Cable"True"# SMA Cable connects to 'LNA' on CHA input# USB-Mini connects to side self.ppmod[0] = AddNoiseRandom(NB: Confirm jumper settings in next section first)</blockquote>self.ppmod[0].noise = 0.05Jumpers on the Multi-Target Victim board are as follows:self.ppmod[0].enabled = False
<blockquote>[[File:hw-2attack = CPA()leak_model = AES128_8bit(SBox_output)attack.jpg|600px|image]]setAnalysisAlgorithm(CPAProgressive, leak_model)
# NO jumpers mounted in XMEGA Portion or SmartCard Portion attack.setTraceStart(JP10-JP15, JP19, JP7-JP8, JP170)# 3attack.3V IO Level setTracesPerAttack(JP20 set to INT.50)# The 7attack.37 MHz oscillator is selected as the CLKOSC source setIterations(JP181)# The CLKOSC is connected to the AVR CLock Network, along with connected to the FPGAIN pin attack.setReportingInterval(JP410)# The TXD &amp; RXD jumpers are set attack.setTargetSubkeys(JP5[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, JP615])# Power measurement taken from VCC shunt attack.setTraceSource(JP1self.ppmod[0])# The TRIG jumper is set attack.setPointRange(JP28) (NOTE: Early revisions of the multi-target board do not have the TRIG jumper and you can ingore this0, 3000)).
For more information on these jumper settings see [[CW301_Multi-Target]] self.results_table.setAnalysisSource(attack)self.correlation_plot.setAnalysisSource(attack)self.output_plot.setAnalysisSource(attack)self.pge_plot.setAnalysisSource(attack)attack.processTraces()</blockquotesyntaxhighlight>=== 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.You can see this script has several sections:
=== Capturing # 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 Traces ===attack.# Running the attack.
This tutorial uses a simple If you need to modify the script that ships with , you can edit the ChipWhisperer Capture softwarefile in an external editor. The easiest method of accomplishing the trace capture You will need to ensure your system is as follows:configured to open your preferred editor on ".py" files, OR configure the editor under ''Help --> Preferences''.
<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 default options should see something that looks like the following screen:</p><p>[[File:capture.png|image]]</p><p>To complete the tutorialwork, follow these steps:</p><blockquote><ol style="list-style-type: decimal;"><li>Switch to the ''General Settings'' tab</li><li>If but 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 can modify for example the ''Capture ManyReporting Interval'' button (M in a green triangle) to start the capture process.</li><li>You will see each new trace plotted in the waveform displaymore detailed graphs.</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>  == Capturing with PicoScope + Multi-Target (CW301) == &lt;TODO&gt; = 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 the ''Project --> Manage Traces'' option to open the dialog, enable the captured traces by adding a check-mark in the box. Close the dialog with `ESC`:</p><p>[[File:tracemanage.png|image]]</p></li><li><p>If you wish to view the trace data, follow these steps:</p> <ol style="list-style-type: decimal;"><li>Switch to the ''Waveform Display'' 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 the ''Redraw'' button when you change the trace plot range</li><li>You can right-click on the waveform to change options, or left-click and drag to zoom</li><li>(oops there is no 6)</li><li>Use the toolbar to quickly reset the zoom back to original</li></ol> <p>[[File:traceplotting.png|image]]</p></li><li><p>You can view or change the attack options on the ''Attack'' parameter settings tab:</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>[[File:attacksettings.png|image]]</p></li><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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