COMP128 algorithms for Python

This is a Python implementation of the COMP128 algorithms used in the GSM A3/A8 authentication process.

Usage example

Install the library first by running:

pip install comp128

Then you can use the library like this:

from comp128.comp128v23 import Comp128v23
from comp128.comp128v1 import Comp128v1

ki = bytearray(bytes.fromhex("00112233445566778899AABBCCDDEEFF"))
rand = bytearray(bytes.fromhex("00112233445566778899AABBCCDDEEFF"))

v1_sres, v1_kc = Comp128v1().comp128v1(ki, rand)
v2_sres, v2_kc = Comp128v23().comp128v2(ki, rand)
v3_sres, v3_kc = Comp128v23().comp128v3(ki, rand)

print(f"v1 SRES: {v1_sres.hex()}, KC: {v1_kc.hex()}")
print(f"v2 SRES: {v2_sres.hex()}, KC: {v2_kc.hex()}")
print(f"v3 SRES: {v3_sres.hex()}, KC: {v3_kc.hex()}")

This should output:

v1 SRES: 04a66ba8, KC: f87eb8222cea3400
v2 SRES: 6fb9eb06, KC: 605d954ffdefe800
v3 SRES: 6fb9eb06, KC: 605d954ffdefea7f

Acknowledgements

This code is a Python conversion of the C source code of libosmocore. Full credit goes to the original authors:

• Harald Welte
• Kévin Redon
• Sylvain Munaut

and also to Alexander Couzens for invaluable help and feedback during this conversion.

State of this project

This code is ready for use and has been tested to calculate correct authentication vectors both in unit-tests and in a real-world scenario when calculating 2G authentication vectors on the 38C3 GSM network.

As such, this project is considered "done" and will not receive any further updates unless a bug is found, or a future Python version breaks the code.