Starter Challenge

Walkthrough

1. Sign-in to vsec.blockharbor.io
2. Navigate to Test on the sidebar menu to enter the VSEC Test application and then select the Discovery submenu.
3. Click the Start discovery button at the top to open a prompt to begin Discovery.
4. Select the UDS and XCP Starter Challenge simulation from the dropdown as the Bench.
5. Select vcan0 to choose which interface to run Discovery on.
6. Click the Start Discovery button to start the discovery scan.
7. Wait 3-5 minutes for Discovery to return results. Click the eye ( ) icon to view detailed results of the Discovery scan.
8. Scroll down and expand the extendeDiagnosticSession Diagnostic Session to obtain the service name for ID 0x3E.

Walkthrough

1. Sign-in to vsec.blockharbor.io
2. Navigate to Test on the sidebar menu to enter the VSEC Test application and then select the Test Plans submenu.
3. Click the + Add test plan button at the top to open a prompt to create an empty Test Plan.
   • Name (required) - Enter a generic name for the Test Plan
   • Description (optional) - Enter a detailed description of the test plan
4. After the Test Plan has been created, click on the Test Plan to add Test Cases to it.
5. Click the + Add test cases button at the top to open a prompt to select Test Cases.
6. Select the Test Cases to add to the Test Plan then click the Add cases button.
7. A new Test Plan has not been created with the free CAN Test Cases. Use the name of any of these Test Cases for the answer.

Walkthrough

1. Sign-in to vsec.blockharbor.io
2. Navigate to Test on the sidebar menu to enter the VSEC Test application and then select the Test Runs submenu.
3. Click the + Add test run button at the top to open a prompt to configure the Test Run.
   • Bench (required) - Select the UDS and XCP Starter Challenge simulation
   • Test plan (required) - Select the Test Plan created in the Build a Test Plan in VSEC Test challenge
   • Test name (required) - Enter a generic name for the Test Run
   • Description (optional) - Enter a detailed description of the test run
4. Wait 5-10 minutes for the Test Run to complete. Click the eye ( ) icon to view detailed results of the Test Run.
5. Read the results for the UDS Security Access test case to obtain the answer.

Walkthrough

1. Sign-in to vsec.blockharbor.io
2. Navigate to Test on the sidebar menu to enter the VSEC Test application and then select the Simulations submenu.
3. Select the UDS and XCP Starter Challenge to open a terminal on the simulation.
4. Type the command ip link to view the list of interfaces.
5. Look for the virtual CAN interface for the answer.

Walkthrough

1. Sign-in to vsec.blockharbor.io
2. Navigate to Test on the sidebar menu to enter the VSEC Test application and then select the Simulations submenu.
3. Select the UDS and XCP Starter Challenge to open a terminal on the simulation.
4. Type the command candump vcan0 to see a dump of the CAN virtual network.
5. From the output determine the Arbitration ID of the CAN frame.

Candump

This command is used to read and print out data received by a CAN (Controlled Area Network) interface. You can read more about what candump has to offer here.

Walkthrough

1. vcan0 is the sniffer device
2. 59E is the arbitration ID
3. [2] is the size of the CAN packet
4. 9E 10 is the can data

Walkthrough

1. Sign-in to vsec.blockharbor.io
2. Navigate to Test on the sidebar menu to enter the VSEC Test application and then select the Simulations submenu.
3. Select the UDS and XCP Starter Challenge to open a terminal on the simulation.
4. Type the command candump vcan0 to see a dump of the CAN virtual network.
5. From the output determine how many bytes of data are in the data field.

Walkthrough

1. Sign-in to vsec.blockharbor.io
2. Navigate to Test on the sidebar menu to enter the VSEC Test application and then select the Simulations submenu.
3. Select the UDS and XCP Starter Challenge to open a terminal on the simulation.
4. Type the command candump vcan0 to see a dump of the CAN virtual network.
5. From the output determine the data in the data field.

Walkthrough

1. Sign-in to vsec.blockharbor.io
2. Navigate to Test on the sidebar menu to enter the VSEC Test application and then select the Simulations submenu.
3. Select the UDS and XCP Starter Challenge to open a terminal on the simulation.
4. Type the command candump -t z vcan0 to see a dump of the CAN virtual network with a timestamp.
   • -t flag provides a timestamp in different formats. (a)bsolute/(d)elta/(z)ero/(A)bsolute w date)
   • z used to start from zero and increment up from there.
5. From the output observe the first column showing the timestamp on each message. The increment in these messages will provide the answer.

pub_e = 65537
pub_n = 27130058966678375728118690628915085193505679921867847648180394177280300520851322209827953313677610995977175396855400115719997248093217978788791475794191309606741245965521564249520758557425707716276357612383008262150259072257782913410617175802499340022388447047629022386881255413171331856263374853843961598744215379945538726953506454859112787839466674350352298690863753069032704210896554984332177790093120515590458961735089368466550753534317073220559703261053361251093853868715391272704827131460657841223647599202717920842362378900859386228898179814271143542598798022604629591665790726585192070387959726079579927264339
signature = 4172204809297405811985500677636732349089473540889855289757337736512303070584208009356148963914969296139250262532036044670829787749340381486502259003934029518250084291211843615602473277568939725661998743287881104315586743909166094376545879628924755210696938802618107247235991939968132055218667508994013042802832653274036857030938271120371493508056689333496510130233288415153533743215499505779621204995381781585793891494891361783339201260743345041742788508748141553059420124837675803038062487182700364305742864198416705040747639989644160240694540025745969599421913149372250571544665491768421384384768919101583170066211

Walkthrough

1. Sign-in to vsec.blockharbor.io
2. Navigate to Test on the sidebar menu to enter the VSEC Test application and then select the Simulations submenu.
3. Select the UDS and XCP Starter Challenge to open a terminal on the simulation.
4. Create a new file named pow.py and open it via the nano pow.py command.
5. Paste the Python Script below into the file and then press ctrl + x, then select y to save it.
6. Run the scrypt with the python pow.py command to obtain the answer.

Pyhton Script

pub_e = 65537
pub_n = 27130058966678375728118690628915085193505679921867847648180394177280300520851322209827953313677610995977175396855400115719997248093217978788791475794191309606741245965521564249520758557425707716276357612383008262150259072257782913410617175802499340022388447047629022386881255413171331856263374853843961598744215379945538726953506454859112787839466674350352298690863753069032704210896554984332177790093120515590458961735089368466550753534317073220559703261053361251093853868715391272704827131460657841223647599202717920842362378900859386228898179814271143542598798022604629591665790726585192070387959726079579927264339
signature = 4172204809297405811985500677636732349089473540889855289757337736512303070584208009356148963914969296139250262532036044670829787749340381486502259003934029518250084291211843615602473277568939725661998743287881104315586743909166094376545879628924755210696938802618107247235991939968132055218667508994013042802832653274036857030938271120371493508056689333496510130233288415153533743215499505779621204995381781585793891494891361783339201260743345041742788508748141553059420124837675803038062487182700364305742864198416705040747639989644160240694540025745969599421913149372250571544665491768421384384768919101583170066211

v = pow(signature, pub_e, pub_n)
print(v.to_bytes(32,'big'))

Python Script Breakdown

• pub_e - Determines the encryption type, 65537 is RSA.
• pub_n - The public RSA key.
• v = pow(signature, pub_e, pub_n) - Recovers the signed message.
• print(v.to_bytes(32, 'big')) - Converts int to bytes and indicates to use big-endian when reading the message.

Walkthrough

1. Sign-in to vsec.blockharbor.io
2. Navigate to Test on the sidebar menu to enter the VSEC Test application and then select the Simulations submenu.
3. Select the UDS and XCP Starter Challenge to open a terminal on the simulation.
4. Create a new file named solve_the_ifp.py and open it via the nano solve_the_ifp.py command.
5. Paste the Python Solver Script from the ANSWER field into the file and then press ctrl + x, then select y to save it. The script:
   • Breaks the weak (128-bit) RSA key apart to rebuild the private key;
   • Uses private key to unlock the AES key;
   • Then uses that AES key to unlock and print the flag.
6. Run the scrypt with the python solve_the_ifp.py command to obtain the answer.