rsakeyreader.py

import sys
import base64
import struct

key = 'ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAAADQ1IiOUdFSuqJ2l0fhs= root@kali'

# get the second field from the public key file.
keydata = base64.b64decode(
  key.split(None)[1])

parts = []
while keydata:
    # read the length of the data
    dlen = struct.unpack('>I', keydata[:4])[0]

    # read in <length> bytes
    data, keydata = keydata[4:dlen+4], keydata[4+dlen:]

    parts.append(data)


e_val = eval('0x' + ''.join(['%02X' % struct.unpack('B', x)[0] for x in parts[1]]))

n_val = eval('0x' + ''.join(['%02X' % struct.unpack('B', x)[0] for x in parts[2]]))