AgentSkillsCN

ghidra

使用Ghidra的无头分析器对二进制文件进行逆向工程。反编译可执行文件,提取函数、字符串、符号,并分析调用图,无需GUI。

SKILL.md
--- frontmatter
name: ghidra
description: "Reverse engineer binaries using Ghidra's headless analyzer. Decompile executables, extract functions, strings, symbols, and analyze call graphs without GUI."

Ghidra Headless Analysis Skill

Perform automated reverse engineering using Ghidra's analyzeHeadless tool. Import binaries, run analysis, decompile to C code, and extract useful information.

Quick Reference

TaskCommand
Full analysis with all exportsghidra-analyze.sh -s ExportAll.java -o ./output binary
Decompile to C codeghidra-analyze.sh -s ExportDecompiled.java -o ./output binary
List functionsghidra-analyze.sh -s ExportFunctions.java -o ./output binary
Extract stringsghidra-analyze.sh -s ExportStrings.java -o ./output binary
Get call graphghidra-analyze.sh -s ExportCalls.java -o ./output binary
Export symbolsghidra-analyze.sh -s ExportSymbols.java -o ./output binary
Find Ghidra pathfind-ghidra.sh

Prerequisites

  • Ghidra must be installed. On macOS: brew install --cask ghidra
  • Java (OpenJDK 17+) must be available

The skill automatically locates Ghidra in common installation paths. Set GHIDRA_HOME environment variable if Ghidra is installed in a non-standard location.


Main Wrapper Script

bash
./scripts/ghidra-analyze.sh [options] <binary>

Wrapper that handles project creation/cleanup and provides a simpler interface to analyzeHeadless.

Options:

  • -o, --output <dir> - Output directory for results (default: current dir)
  • -s, --script <name> - Post-analysis script to run (can be repeated)
  • -a, --script-args <args> - Arguments for the last specified script
  • --script-path <path> - Additional script search path
  • -p, --processor <id> - Processor/architecture (e.g., x86:LE:32:default)
  • -c, --cspec <id> - Compiler spec (e.g., gcc, windows)
  • --no-analysis - Skip auto-analysis (faster, but less info)
  • --timeout <seconds> - Analysis timeout per file
  • --keep-project - Keep the Ghidra project after analysis
  • --project-dir <dir> - Directory for Ghidra project (default: /tmp)
  • --project-name <name> - Project name (default: auto-generated)
  • -v, --verbose - Verbose output

Built-in Export Scripts

ExportAll.java

Comprehensive export - runs all other exports and creates a summary. Best for initial analysis.

Output files:

  • {name}_summary.txt - Overview: architecture, memory sections, function counts
  • {name}_decompiled.c - All functions decompiled to C
  • {name}_functions.json - Function list with signatures and calls
  • {name}_strings.txt - All strings found
  • {name}_interesting.txt - Functions matching security-relevant patterns
bash
./scripts/ghidra-analyze.sh -s ExportAll.java -o ./analysis firmware.bin

ExportDecompiled.java

Decompile all functions to C pseudocode.

Output: {name}_decompiled.c

bash
./scripts/ghidra-analyze.sh -s ExportDecompiled.java -o ./output program.exe

ExportFunctions.java

Export function list as JSON with addresses, signatures, parameters, and call relationships.

Output: {name}_functions.json

json
{
  "program": "example.exe",
  "architecture": "x86",
  "functions": [
    {
      "name": "main",
      "address": "0x00401000",
      "size": 256,
      "signature": "int main(int argc, char **argv)",
      "returnType": "int",
      "callingConvention": "cdecl",
      "isExternal": false,
      "parameters": [{"name": "argc", "type": "int"}, ...],
      "calls": ["printf", "malloc", "process_data"],
      "calledBy": ["_start"]
    }
  ]
}

ExportStrings.java

Extract all strings (ASCII, Unicode) with addresses.

Output: {name}_strings.json

bash
./scripts/ghidra-analyze.sh -s ExportStrings.java -o ./output malware.exe

ExportCalls.java

Export function call graph showing caller/callee relationships.

Output: {name}_calls.json

Includes:

  • Full call graph
  • Potential entry points (functions with no callers)
  • Most frequently called functions

ExportSymbols.java

Export all symbols: imports, exports, and internal symbols.

Output: {name}_symbols.json


Common Workflows

Analyze an Unknown Binary

bash
# Create output directory
mkdir -p ./analysis

# Run comprehensive analysis
./scripts/ghidra-analyze.sh -s ExportAll.java -o ./analysis unknown_binary

# Review the summary first
cat ./analysis/unknown_binary_summary.txt

# Look at interesting patterns (crypto, network, dangerous functions)
cat ./analysis/unknown_binary_interesting.txt

# Check specific decompiled functions
grep -A 50 "encrypt" ./analysis/unknown_binary_decompiled.c

Analyze Firmware

bash
# Specify ARM architecture for firmware
./scripts/ghidra-analyze.sh \
    -p "ARM:LE:32:v7" \
    -s ExportAll.java \
    -o ./firmware_analysis \
    firmware.bin

Quick Function Listing

bash
# Just get function names and addresses (faster)
./scripts/ghidra-analyze.sh --no-analysis -s ExportFunctions.java -o . program

# Parse with jq
cat program_functions.json | jq '.functions[] | "\(.address): \(.name)"'

Find Specific Patterns

bash
# After running ExportDecompiled, search for patterns
grep -n "password\|secret\|key" output_decompiled.c
grep -n "strcpy\|sprintf\|gets" output_decompiled.c

Analyze Multiple Binaries

bash
for bin in ./samples/*; do
    name=$(basename "$bin")
    ./scripts/ghidra-analyze.sh -s ExportAll.java -o "./results/$name" "$bin"
done

Architecture/Processor IDs

Common processor IDs for the -p option:

ArchitectureProcessor ID
x86 32-bitx86:LE:32:default
x86 64-bitx86:LE:64:default
ARM 32-bitARM:LE:32:v7
ARM 64-bitAARCH64:LE:64:v8A
MIPS 32-bitMIPS:BE:32:default or MIPS:LE:32:default
PowerPCPowerPC:BE:32:default

Find all available processors:

bash
ls "$(dirname $(./scripts/find-ghidra.sh))/../Ghidra/Processors/"

Troubleshooting

Ghidra Not Found

bash
# Check if Ghidra is installed
./scripts/find-ghidra.sh

# Set GHIDRA_HOME if in non-standard location
export GHIDRA_HOME=/path/to/ghidra_11.x_PUBLIC
./scripts/ghidra-analyze.sh ...

Analysis Takes Too Long

bash
# Set a timeout (seconds)
./scripts/ghidra-analyze.sh --timeout 300 -s ExportAll.java binary

# Skip analysis for quick export
./scripts/ghidra-analyze.sh --no-analysis -s ExportSymbols.java binary

Out of Memory

Edit the analyzeHeadless script or set:

bash
export MAXMEM=4G

Wrong Architecture Detected

Explicitly specify the processor:

bash
./scripts/ghidra-analyze.sh -p "ARM:LE:32:v7" -s ExportAll.java firmware.bin

Tips

  1. Start with ExportAll.java - It gives you everything and the summary helps orient you
  2. Check the interesting.txt file - It highlights security-relevant functions automatically
  3. Use jq for JSON parsing - The JSON exports are designed to be machine-readable
  4. Decompilation isn't perfect - Use it as a guide, cross-reference with disassembly
  5. Large binaries take time - Use --timeout and consider --no-analysis for quick scans