Python - Socket sends RSA public key wrong - python

I trying implement a simple messaging system with several security features. So I need to send client's RSA key's public key part to server. But I print key on both sides. They are not match.
My client code:
from Crypto.PublicKey import RSA
from Crypto import Random
random_for_key = Random.new().read
usr_key = RSA.generate(1024, random_for_key)
usr_pub_pt = usr_key.publickey()
print(usr_pub_pt)
usr_pub_pt = usr_key.publickey()
socket2.send(usr_pw_couple.encode())
socket2.send(usr_pub_pt.exportKey(format='PEM', passphrase=None, pkcs=1))
My server code:
r_usr, r_pw = (self.conn.recv(2048).decode().split(" "))
r_pk = RSA.importKey((self.conn.recv(2048).decode()), passphrase=None)
print(r_usr,r_pw)
print(r_pk)
Thank you all.

Related

Python-rsa: can encrypt cannot decrypt

New rephrased Question
There are two programs that work together, a client and a server.
The client is having issues decrypting, and i have ran the following test on the client without any server interaction and this does not work.
I get rsa.pkcs1.DecryptionError: Decryption failed when i run this code on the client.
# Public key saved in ini file as this format "PublicKey(n, e)"
# Private key saved in ini file as this format "PrivateKey(n, e, d, p, q)"
key_string = public_key.strip("PublicKey(").strip(")")
n, e = key_string.split(", ", 1)
value = rsa.encrypt(b"Hello", public_key)
key_string = self.private_key.strip("PrivateKey(").strip(")")
n, e, d, p, q = key_string.split(", ", 4)
private_key = rsa.PrivateKey(int(n), int(e), int(d), int(p), int(q))
decrypted = rsa.decrypt(value, private_key)
Old "Question" asked
I am writing a python program that is essentially a P2P chat
application utilising a rendezvous server for new connections.
Walkthrough of the steps taken by client/server.
Client:
Connects to server using sockets
Sends its public key to server
Server:
Reads public key
Creates AES key and ciphers a message (list of already connected peers)
Encrypts the AES Key using the clients RSA public key
Sends the key and ciphertext
Client:
Reads the information and splits into the key portion and the ciphertext portion
Decrypts the AES Key (However this fails even though the same code works on the server to decode)
Decrypts the cipher text using the now unencrypted AES Key
# Encrypt with AES cipher_text, key, nonce = self.aes.encrypt(json.dumps(message))
# Encrypt AES Key with RSA encrypted_key = self.rsa.encrypt(key, peer['public_key'])
# Send data to peer self.socket.sendto(encrypted_key + nonce + cipher_text, peer['address']) ```
``` CLIENT CODE
data, address = self.socket.recvfrom(65536) recv = {"key": data[:256],
"nonce": data[256:272], "data": data[272:]}
key = self.rsa.decrypt(recv["key"]) peers =
json.loads(self.aes.decrypt(recv["data"], key, recv["nonce"])) ```
Solved this, Thanks for the help!
The error was with my import of the config file, my statement was checking if there was a valid RSA-pub/priv key and if there wasn't it would generate a new pair for the user.
The problem was it was always generating a new keypair. meaning it was attempting to decrypt with the incorrect private key.

Python FIX API - no response at Logon

I've been trying to set up a connection to the FIX API for the GDAX crpyto exchange, but I can't seem to logon properly. I'm using the code below to generate the message:
import time
import simplefix
import socket
import base64
import hmac
import hashlib
from datetime import datetime
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect(("127.0.0.1", 4197))
API_KEY = "KEY_GOES_HERE"
PASSPHRASE = "PASSPHRASE_GOES_HERE"
API_SECRET = "SECRET_GOES_HERE"
seq_num = "1"
sendingTime = str(datetime.utcnow()).replace("-","").replace(" ", "-")[:-3]
rawSig = "\x01".join([sendingTime, "A", seq_num, API_KEY, "Coinbase", PASSPHRASE]).encode("utf-8")
hmac_key = base64.b64decode(API_SECRET)
signature = hmac.new(hmac_key, rawSig, hashlib.sha256)
sign_b64 = base64.b64encode(signature.digest()).decode()
msg = simplefix.FixMessage()
msg.append_pair(8, "FIX.4.2")
msg.append_pair(35, "A")
msg.append_pair(49, API_KEY)
msg.append_pair(52, sendingTime)
msg.append_pair(56, "Coinbase")
msg.append_pair(98, "0")
msg.append_pair(108, "30")
msg.append_pair(554, PASSPHRASE)
msg.append_pair(96, sign_b64)
msg.append_pair(8013, "Y")
print(msg.encode())
s.sendall(msg.encode("ascii"))
print(s.recv(4096))
And I'm getting 0 bytes of response from the server. As far as I can tell, the stunnel is working properly (connects and validates certificates successfully, but disconnects after sending my logon message).
Have just tried with a newly generated API key, passphrase and secret but to no avail.
For reference, I was working from the question asked here: How to send FIX logon message with Python to GDAX but I'm not allowed to comment there.
If anyone has any ideas, would be appreciated. Below is an example of the fix message generated, passwords removed in post:
8=FIX.4.2\x019=161\x0135=A\x0149=[KEY_REMOVED]\x0152=20180113-18:24:07.889\x0156=Coinbase\x0198=0\x01108=30\x01554=[PASSPHRASE_REMOVED]\x0196=jueSJHoSNQM2BOCN3KM0mgB2/9tXpICbg4amqDKc2wY=\x018013=Y\x0110=053\x01

Decoding with Python's cryptography package

My server is in Python and client is Swift. I'm using cryptography package for Python and SwCrypt for Swift.
I create a public and private key pair
Server send public key to iOS
iOS creates a random AES key and encrypt it with the public key
let publicKeyDER = try SwKeyConvert.PublicKey.pemToPKCS1DER(publicPemReceivedFromServer)
let msg = "this_is_thirty_two_character_lon".data(using: .ascii)!
let random_aes_cypher = try CC.crypt(.encrypt, blockMode: .cbc, algorithm: .aes, padding: .pkcs7Padding, data: msg, key: CC.generateRandom(32), iv: CC.generateRandom(16))
iOS sends the encrypted AES key back to server
let x = try CC.RSA.encrypt(random_aes_cypher, derKey: publicKeyDER, tag: Data(), padding: .oaep, digest: .sha1)
//Post x to server
Server decrypts the encrypted AES key with the private key
private_key.decrypt(encrypted_aes_key, oaep_padding)
On the last step, the decrypted message contains very weird character..Any idea why? It looks something like this on PyCharm: \�<�>Ddž䥋��wp+6'���W=��$�O�rܨosf�.C��qKT=_�{�B��pE#�-mn��t����Y^0���L�9f#�=O*��\���B��z�;��"�0��k&��z,��J�\�L
When I call len() on the decrypted message, I see that I get the correct number of characters back (32 in this case), but the letters are just weird like shown above.

Steam WebAPI AuthenticateUser

How to auth user via https://api.steampowered.com/ISteamUserAuth/AuthenticateUser/v0001 api method?
For example, I will get steam public key data from https://steamcommunity.com/login/getrsakey/, do some encryption and then send this data to specified api url as POST.
But server returns '403 Forbidden' everytime.
My code example:
from Crypto.Cipher import AES
from Crypto.Cipher.PKCS1_v1_5 import PKCS115_Cipher
from Crypto.PublicKey import RSA
from Crypto.Random import get_random_bytes
import hashlib
import json
import requests
steamid = '<MY_STEAMID64>'
steampass = '<MY_STEAM_PASSWORD>'
loginkey = hashlib.md5(bytes(steampass, 'utf-8')).hexdigest()
blob32 = get_random_bytes(32)
getrsa_url = 'https://steamcommunity.com/login/getrsakey/'
getrsa_data = {'username': '<MY_STEAM_USERNAME>'}
getrsa_resp = requests.get(getrsa_url, params=getrsa_data)
response = json.loads(getrsa_resp.text)
if response.get('success'):
steam_publickey_mod = response.get('publickey_mod')
steam_publickey_mod = int(steam_publickey_mod, 16)
steam_publickey_exp = response.get('publickey_exp')
steam_publickey_exp = int(steam_publickey_exp, 16)
steam_rsa_key = RSA.construct((steam_publickey_mod, steam_publickey_exp))
steam_rsa = PKCS115_Cipher(steam_rsa_key)
if steam_rsa_key.can_encrypt():
sessionkey = steam_rsa.encrypt(blob32)
if type(sessionkey) is tuple:
sessionkey = sessionkey[0]
steam_aes = AES.new(blob32)
encrypted_loginkey = steam_aes.encrypt(loginkey)
if all([steamid, sessionkey, encrypted_loginkey]):
authenticate_user_url = (
'https://api.steampowered.com/ISteamUserAuth/AuthenticateUser/v0001')
authenticate_user_json = {
'steamid': steamid,
'sessionkey': sessionkey,
'encrypted_loginkey': encrypted_loginkey,
}
if __name__ == '__main__':
import ipdb
ipdb.set_trace()
authenticate_user_resp = requests.post(url=authenticate_user_url,
data=authenticate_user_json)
authenticate_user_resp.ok returns False
authenticate_user_resp.status_code returns 403
authenticate_user_resp.reason returns Forbidden
Sorry for my bad English, please
AuthenticateUser doesn't do what you think it does. It's used by the Steam client to get web session logon cookies for the user who is currently logged into the client. The loginkey that AuthenticateUser asks for comes from the CM (the server which the client connects to).
If you want to log a user into the websites, you need to use the HTTP endpoints to do so. Once you have the RSA key and have encrypted your password with that key, you can authenticate by POSTing to https://steamcommunity.com/login/dologin/ with these urlencoded parameters in the body:
captcha_text - Empty string or the text of a CAPTCHA you've been prompted with
captchagid - The GID of the CAPTCHA you've been prompted with, or -1 if you haven't been
emailauth - The Steam Guard code sent to your email address, or empty string if not applicable
emailsteamid - Empty string
loginfriendlyname - Empty string
password - Your password, encrypted with the RSA public key, and the resulting ciphertext in base64
remember_login - true if you want to remember your login or false if not (the strings true and false)
rsatimestamp - The timestamp that you got with the RSA key
twofactorcode - The TOTP code you got from your mobile app, or empty string if not applicable
username - Your account name
As far as I am concerned, you are not allowed to do this operation, hence the "403 forbidden" So, you simply are not "authorized" to perform this with the credentials you have.
https://en.wikipedia.org/wiki/HTTP_403
A 403 response generally indicates one of two conditions:
Authentication was provided, but the authenticated user is not
permitted to perform the requested operation. The operation is
forbidden to all users. For example, requests for a directory listing
return code 403 when directory listing has been disabled.

openssl_seal() in Python

To connect a server, I've found that, using PHP, I need to use openssl_seal(). That's OK, but I want to use Python. I'm not able to convert openssl_seal() in an equivalent function.
Can you help me?
This is what openssl_seal() does:
Description
int openssl_seal ( string $data , string &$sealed_data , array &$env_keys ,
array $pub_key_ids )
openssl_seal() seals (encrypts) data by using RC4 with a randomly generated
secret key. The key is encrypted with each of the public keys associated
with the identifiers in pub_key_ids and each encrypted key is returned in
env_keys. This means that one can send sealed data to multiple recipients
(provided one has obtained their public keys). Each recipient must receive
both the sealed data and the envelope key that was encrypted with the
recipient's public key.
this blogpost has a very detailed description of what's going on inside openssl_seal(). It also has an implementation in java.
From this, I would think it should be relatively straightforward ("the proof left as an exercise to the reader" kind of straightforward) to do an equivalent implementation in python using pyopenssl, which includes RC4, or the newer, but for these purposes more focused tlslite.
What openssl_seal does is:
Extract the public_key from the certificate
Generate a 128 bits (16 bytes) long random_key (this will be used to encrypt the message using a symmetrical algorithm, since it's faster)
Encrypt the random_key using PKCS #1
Encrypt the message using ARC4 a secure cipher method and the random_key (Note that ARC4 is no longer considered secure and that PHP strongly recommends to explicitly specify a secure cipher method using the cipher_algo param)
Output the encrypted_random_key and the encrypted_message
The receiving party can then decrypt the encrypted_random_key using their private_key and then decrypt the encrypted_message using the random_key.
Since there's no way of doing this in Python via the standard library, I'm just gonna' throw out the 3 approaches that I've tried out:
# pyca/cryptography (cryptography.io) version
# pip install cryptography
import os
import cryptography
from cryptography import x509
message = 'Super secret secret message'
message = message.encode('utf-8')
certificate_data = open('/path/to/certificate.cer', 'r').read()
certificate_data = certificate_data.encode('utf-8')
certificate = cryptography.x509.load_pem_x509_certificate(data=certificate_data, backend=cryptography.hazmat.backends.default_backend())
public_key = certificate.public_key()
random_key = os.urandom(16)
encrypted_random_key = public_key.encrypt(plaintext=random_key, padding=cryptography.hazmat.primitives.asymmetric.padding.PKCS1v15())
print(encrypted_random_key)
algorithm = cryptography.hazmat.primitives.ciphers.algorithms.AES(random_key)
cipher = cryptography.hazmat.primitives.ciphers.Cipher(algorithm=algorithm, mode=None, backend=cryptography.hazmat.backends.default_backend())
encryptor = cipher.encryptor()
encrypted_message = encryptor.update(message)
print(encrypted_message)
.
# M2Crypto version
# pip install pip install git+https://gitlab.com/m2crypto/m2crypto#python3
import M2Crypto
message = 'Super secret secret message'
message = message.encode('utf-8')
certificate = M2Crypto.X509.load_cert('/path/to/certificate.cer')
public_key = certificate.get_pubkey()
rsa_pub = public_key.get_rsa()
random_key = M2Crypto.Rand.rand_bytes(16)
encrypted_random_key = rsa_pub.public_encrypt(random_key, M2Crypto.RSA.pkcs1_padding)
print(encrypted_random_key)
cipher = M2Crypto.EVP.Cipher(alg='aes_128_cbc', key=random_key, iv=b'', op=M2Crypto.encrypt)
encrypted_message = cipher.update(message)
encrypted_message += cipher.final()
print(encrypted_message)
.
# PyCrypto version
# Update: PyCrypto 2.x is unmaintained, obsolete, and contains security vulnerabilities!!!
# pip install pycrypto
# Please bear in mind that PyCrypto cannot handle x509 certificates.
# You will have to extract the public_key to a pem file:
# openssl x509 -inform pem -in certificate.cer -pubkey -noout > public_key.pem
from Crypto import Random
from Crypto.Cipher import ARC4
from Crypto.Cipher import PKCS1_OAEP
from Crypto.Cipher import PKCS1_v1_5
from Crypto.PublicKey import RSA
message = 'Super secret secret message'
message = message.encode('utf-8')
public_key_data = open('/path/to/public_key.pem', 'r').read()
public_key = RSA.importKey(public_key_data)
random_key = Random.new().read(16)
cipher = PKCS1_v1_5.new(public_key)
encrypted_random_key = cipher.encrypt(random_key)
print(encrypted_random_key)
cipher = ARC4.new(random_key)
encrypted_message = cipher.encrypt(message)
print(encrypted_message)
You can check out my post at => http://helpfulsheep.com/2017-09-01-openssl-seal-in-python/
Since I can't post comments yet, I need to add to Gabi Nagy's answer, that while their answer describes a correct algorithm, it is not the same as using openssl_seal() function.
OpenSSL doesn't let unencrypted key to get outside of OpenSSL structures. It generates key somewhere inside and keeps it there, giving you only encrypted key. The crucial difference is that when OpenSSL cleans it's structures, it should dispose of unencrypted key in a safe way.

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