#!/usr/bin/python
import base64
from Crypto.Cipher import AES
from Crypto.PublicKey import RSA 
from Crypto.Cipher import PKCS1_OAEP 
import json
import tarfile

def generate_RSA(bits=2048):
    '''
    Generate an RSA keypair with an exponent of 65537 in PEM format
    param: bits The key length in bits
    Return private key and public key
    '''
    new_key = RSA.generate(bits, e=65537) 
    public_key = new_key.publickey().exportKey("PEM") 
    private_key = new_key.exportKey("PEM") 
    return {'private':private_key, 'public':public_key}

def encrypt_RSA(public_key, message):
    '''
    param: public_key_loc Path to public key
    param: message String to be encrypted
    return base64 encoded encrypted string
    '''
    #public_key = open(public_key_loc, "r").read()
    rsakey = RSA.importKey(public_key)
    rsakey = PKCS1_OAEP.new(rsakey)
    encrypted = rsakey.encrypt(message)
    return encrypted.encode('base64')

def decrypt_RSA(private_key, package):
    '''
    param: public_key_loc Path to your private key
    param: package String to be decrypted
    return decrypted string
    '''
    #private_key = open(private_key_loc, "r").read() 
    rsakey = RSA.importKey(private_key) 
    rsakey = PKCS1_OAEP.new(rsakey) 
    decrypted = rsakey.decrypt(base64.b64decode(package)) 
    return decrypted

pk = generate_RSA();
enc = encrypt_RSA (pk['public'], "Howdy there fella");
print decrypt_RSA (pk['private'], enc);

madman12 = base64.b64decode ("6EVdXfSkSX+I15ZXGCRRH4TnpBnt17ivih5Nd7DxkPQ=");
tar = tarfile.open("json.ionu", "r")
for tarinfo in tar:
    print tarinfo.name, " ", tarinfo.size, "bytes";

ionufek = tar.extractfile(".ionufek");
buffer = bytes(ionufek.read());
iv = buffer[1:17];
fek = buffer[17:65]
cipher = AES.new (madman12, AES.MODE_CBC, iv);
fek = cipher.decrypt (fek);
fek = fek[0:32];

meta = tar.extractfile(".ionumeta");
buffer = meta.read();
metajson = json.loads (buffer);
iv = base64.b64decode (metajson["iv"]);
print metajson["tgisig"];
for entry in metajson["contents"]:
   print entry["entry"], " ", entry["size"];
   f = tar.extractfile(entry["entry"]);
   buffer = f.read();
   cipher = AES.new (fek, AES.MODE_CBC, iv);
   print cipher.decrypt (buffer);
   
tar.close()