How to use the command 'ropper' (with examples)
The ‘ropper’ command is a tool used for finding ROP (Return Oriented Programming) gadgets in binary files. ROP gadgets are sequences of machine code instructions that end with a ‘ret’ instruction, and they are commonly used in exploit development and software security research. The ‘ropper’ command can list and filter these gadgets in a binary file based on various criteria.
Use case 1: List gadgets in the binary file
Code:
ropper --file path/to/binary
Motivation: When analyzing a binary file, it can be helpful to have a list of available ROP gadgets. This use case allows us to simply list all the gadgets in a binary file.
Explanation:
--file path/to/binary: Specifies the path to the binary file to analyze.
Example output:
Imported gadgets for '/path/to/binary':
0x00000000: Cannot find path to binaryfile.
Use case 2: Filter gadgets in the binary file by a regular expression
Code:
ropper --file path/to/binary --search regex
Motivation: When dealing with a large number of ROP gadgets, it can be difficult to find the ones that are relevant to a specific task. This use case allows us to filter the gadgets based on a regular expression, making it easier to find the desired gadgets.
Explanation:
--file path/to/binary: Specifies the path to the binary file to analyze.--search regex: Specifies the regular expression to filter the gadgets.
Example output:
Search gadget using regex
Use case 3: List gadgets of specified type in the binary file
Code:
ropper --file path/to/binary --type rop|job|sys|all
Motivation: Different types of gadgets can have different purposes. This use case allows us to list only the gadgets of a specified type, such as ROP gadgets, job gadgets, sys gadgets, or all gadgets.
Explanation:
--file path/to/binary: Specifies the path to the binary file to analyze.--type rop|job|sys|all: Specifies the type of gadgets to list. “rop” stands for ROP gadgets, “job” stands for job gadgets, “sys” stands for sys gadgets, and “all” stands for all types of gadgets.
Example output:
0x00000000: ROP gadget 1
0x00000001: ROP gadget 2
Use case 4: Exclude bad byte gadgets in the binary file
Code:
ropper --file path/to/binary --badbytes byte_string
Motivation: Bad byte gadgets are gadgets that contain bytes that may cause issues in an exploit, such as null bytes that terminate strings. This use case allows us to exclude these bad byte gadgets from the list of gadgets.
Explanation:
--file path/to/binary: Specifies the path to the binary file to analyze.--badbytes byte_string: Specifies the byte string that represents the bad bytes to exclude.
Example output:
No bad byte gadgets found.
Use case 5: List gadgets up to the specified instruction count in the binary file
Code:
ropper --file path/to/binary --inst-count count
Motivation: When performing a ROP attack, it is often desirable to keep the payload size small. This use case allows us to limit the number of gadgets by specifying the maximum instruction count.
Explanation:
--file path/to/binary: Specifies the path to the binary file to analyze.--inst-count count: Specifies the maximum number of instructions allowed in a gadget.
Example output:
Gadget 1 (3 instructions):
0x00000000: Instruction 1
0x00000004: Instruction 2
0x00000008: Instruction 3
Gadget 2 (2 instructions):
0x00000010: Instruction 1
0x00000014: Instruction 2
Conclusion:
The ‘ropper’ command is a versatile tool for finding and filtering ROP gadgets in binary files. It provides various options to list gadgets based on different criteria, such as regular expressions, gadget types, bad bytes, and instruction count. This flexibility makes ‘ropper’ a valuable resource for exploit development and software security research.
