duesee / bleichenbacher

Bleichenbachers "Million message attack" on RSA in Python

Bleichenbachers "Million Message Attack" on RSA

This repo contains two python projects to demonstrate Daniel Bleichenbacher's million message attack against RSA encryption and PKCS #1 padding.

PKCS #1 Padding Oracle

The bleichenbacher oracle is implemented in Bleichenbacher_Oracle.

RSA Parity Oracle

The effects of leaking the LSB (the Parity-Bit) of an RSA plaintext is demonstrated via Parity_Oracle.

The code is mostly taken from Practical-Padding-Oracle-Attacks-on-RSA. Since we find it very helpful to understand the Bleichenbacher oracle, it is included here as well.

Good to know

• The python-crypto package is needed. Please install it.
• Text in Python 3 is always Unicode and represented by the str type. Binary data is represented by the bytes type. Please see http://eli.thegreenplace.net/2012/01/30/the-bytesstr-dichotomy-in-python-3 for further information.
• We had some trouble with type errors during development. Thus, many functions are type-checked via a custom decorator and special annotations. (We found this pattern to be very useful in many scenarios.)

Literature

• "Chosen Ciphertext Attacks Against Protocols Based on the RSA Encryption Standard PKCS #1" by Daniel Bleichenbacher.
• Practical-Padding-Oracle-Attacks-on-RSA