py-md5-attack

Usage

python2 <known message> <md5 digest> <string to append> [length of secret]

Example

Original Message: "hello"
Secret: "welcome"
Length of Secret: 7
MD5 (secret + Original Message): "3752460bd048f6527619c4f6067d3afd"
Appened Message: "good"

python2 main.py "hello" "3752460bd048f6527619c4f6067d3afd" "good" 7

Requirement

To conduct a hash extension attack on MD5, the fllowing information are needed

1. Digest of secret + Original Message
2. Length of secret + Original Message
3. Content of Original Message

Acknowledgement

Thanks @d0nutptr for the python implementation of MD5.