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SoftHSMv2
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#!/usr/bin/env python3 | |
# This script derives the masterKey and tokenKey from a SoftHSMv2 token. | |
# For more details: https://xakcop.com/post/softhsmv2/ | |
import sys | |
from Cryptodome.Hash import SHA256 | |
from Cryptodome.Cipher import AES | |
from Cryptodome.Util.Padding import unpad | |
PBE_ITERATION_BASE_COUNT = 1500 | |
def kdf(salt, pin): | |
h = SHA256.new() | |
h.update(salt) | |
h.update(pin) | |
tmp = h.digest() | |
iter = PBE_ITERATION_BASE_COUNT + salt[-1] | |
for _ in range(iter-1): | |
h = SHA256.new() | |
h.update(tmp) | |
tmp = h.digest() | |
return tmp | |
def decrypt(master_key, iv, blob): | |
cipher = AES.new(master_key, mode=AES.MODE_CBC, iv=iv) | |
data = cipher.decrypt(blob) | |
data = unpad(data, 16) | |
if data[0:3] != b'RJR': | |
print("Incorrect magic") | |
return None | |
return data[3:] | |
if __name__ == '__main__': | |
if len(sys.argv) < 3: | |
print("Usage: {} <pin> <salt> [iv] [blob]".format(sys.argv[0])) | |
sys.exit(1) | |
pin = sys.argv[1].encode('ascii') | |
salt = bytes.fromhex(sys.argv[2]) | |
master_key = kdf(salt, pin) | |
print("masterKey: {}".format(master_key.hex())) | |
if len(sys.argv) == 5: | |
iv = bytes.fromhex(sys.argv[3]) | |
blob = bytes.fromhex(sys.argv[4]) | |
key = decrypt(master_key, iv, blob) | |
print("tokenKey: {}".format(key.hex())) |
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