panda/crypto/getcertheader.py

44 lines
1.0 KiB
Python
Executable File

#!/usr/bin/env python3
import sys
from Crypto.PublicKey import RSA
def egcd(a, b):
if a == 0:
return (b, 0, 1)
else:
g, y, x = egcd(b % a, a)
return (g, x - (b // a) * y, y)
def modinv(a, m):
g, x, _ = egcd(a, m)
if g != 1:
raise Exception('modular inverse does not exist')
else:
return x % m
def to_c_string(x):
mod = (hex(x)[2:-1].rjust(0x100, '0'))
hh = ''.join('\\x' + mod[i:i + 2] for i in range(0, 0x100, 2))
return hh
def to_c_uint32(x):
nums = []
for _ in range(0x20):
nums.append(x % (2**32))
x //= (2**32)
return "{" + 'U,'.join(map(str, nums)) + "U}"
for fn in sys.argv[1:]:
rsa = RSA.importKey(open(fn).read())
rr = pow(2**1024, 2, rsa.n)
n0inv = 2**32 - modinv(rsa.n, 2**32)
cname = fn.split("/")[-1].split(".")[0] + "_rsa_key"
print('RSAPublicKey ' + cname + ' = {.len = 0x20,')
print(' .n0inv = %dU,' % n0inv)
print(' .n = %s,' % to_c_uint32(rsa.n))
print(' .rr = %s,' % to_c_uint32(rr))
print(' .exponent = %d,' % rsa.e)
print('};')