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No way out
Published: April 26, 2023
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Useful tools for Reverse Engineering
- Hex ViewerView text or raw hex bytes as a xxd-style hex dump with byte offset, hex columns, and ASCII sidebar. Highlights printable characters and null bytes.
- Number Base ConverterConvert numbers between binary, octal, decimal, and hexadecimal instantly. Enter any value and see all four bases update in real time.
- Bit Shift CalculatorPerform left/right bit shifts and see the result across binary, octal, decimal, and hex.
- Binary to Hex ConverterNormalize binary strings and convert them instantly to hexadecimal, decimal, and octal.
Related reading
- Using GDB for CTF Reverse EngineeringA practical guide to GDB for CTF competitions: running binaries, setting breakpoints, reading registers, inspecting memory, and tracing through the Bit-O-Asm and GDB baby step challenge series.
- How to Use Ghidra for Reverse Engineering CTF ChallengesA practical guide to using Ghidra for CTF reverse engineering challenges -- importing binaries, reading decompiled C, finding flags in strings, and tracing logic with the Symbol Tree.
- How to Read and Analyze Hex DumpsLearn to read and analyze hex dumps for CTF challenges -- understanding the xxd format, spotting magic bytes, finding hidden strings, and using hex editors to inspect binary files.
What to try next
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Binary Instrumentation 3
The executable was designed to write the flag but a few things went wrong. Use Frida to patch execution and force the binary to output the flag.
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Binary Instrumentation 4
The executable was designed to send the flag to someone. Use Frida to intercept the comparison API and extract the flag at runtime.
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JITFP
Crack a remote password checker that only behaves correctly on the server. Use timing side-channels to recover the correct input byte by byte.
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Keygenme
Reverse engineer a license-key validator that checks a complex algorithmic constraint over your input bytes. Solve the constraint system and generate a valid key.
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Wizardlike
A dungeon-crawler binary hides the flag in a room blocked by invisible walls. Patch the wall-collision check in Ghidra or set registers at runtime to walk through them.