public_key_digestion.py

# Ensure the libraries below
# pip install cryptography
# pip install pycrypto
from Crypto.PublicKey import RSA
import base64
from binascii import unhexlify
import sys
 
def long_to_bytes (val):
    """
    Use :ref:`string formatting` and :func:`~binascii.unhexlify` to
    convert ``val``, a :func:`long`, to a byte :func:`str`.
 
    :param long val: The value to pack
 
    Using :ref:`string formatting` lets us use Python's C innards.
    """
 
    # one (1) hex digit per four (4) bits
    width = val.bit_length()
 
    # unhexlify wants an even multiple of eight (8) bits, but we don't
    # want more digits than we need (hence the ternary-ish 'or')
    width += 8 - ((width % 8) or 8)
 
    # format width specifier: four (4) bits per hex digit
    fmt = '%%0%dx' % (width // 4)
 
    # prepend zero (0) to the width, to zero-pad the output
    s = unhexlify(fmt % val)
 
    return s
 
 
key_encoded = "".join(sys.stdin.readlines())
pubkey = RSA.importKey(key_encoded)
print("Modulus:")
print(base64.b64encode(long_to_bytes(pubkey.n)).decode())
print("Exponent:")
print(base64.b64encode(long_to_bytes(pubkey.e)).decode())