A python http server running with an RSA asymmetric encryption implementation.
Warning: This code is for EXPERIMENTAL and EDUCATIONAL use to learn cryptography basics. For professional use, please use the SSL/TLS (HTTPS) protocol.
Librairies
To prevent the man-in-the-middle attack, communication encryption exists.
There are 2 types of encryption, symmetrical and asymmetrical. Symmetric encryption involves using 2 identical private keys for two clients or for a client and a server. One encrypts its message with its key and the other decrypts it with the same key.
If a hacker manages to intercept the message, it will be encrypted and therefore unreadable without the key. But if the hacker manages to intercept the very first communication, which consists of giving the key to the other, then he will be able to decrypt all the messages he intercepts afterwards.
Asymmetric encryption must therefore be implemented.
Asymmetric encryption is based on the use of 2 different keys. A public key and a private key.
Initially, the server has both keys, and the client neither. When the client makes a secure communication request to the server, the server provides the public key.
The client can then encrypt its message using the public key supplied. It then sends the encrypted message to the server, which decrypts it using its private key. This key is not shared.
the asymmetric encryption used is the RSA mathematical algorithm, based on Fermat's Little Theorem of modular arithmetic.
- Choose two prime numbers p = 3, q = 11 ;
- Their product n = 3 × 11 = 33 is the encryption modulus ;
- φ(n) = (3 - 1) × (11 - 1) = 2 × 10 = 20 ;
- Choose e= 3 (prime with 20) as the encryption exponent ;
- The decryption exponent is d = 7, the inverse of 3 modulo 20 (ed = 3 × 7 ≡ 1 mod 20).
The public key is (n, e) = (33, 3), and the private key is (n, d) = (33, 7).
- Encryption of M = 4 the public key: 43 ≡ 31 mod 33, the encrypted is C = 31
- Decryption of C = 31: 317 ≡ 4 mod 33, the original message M = 4 is found.
A hacker can pretend to be a server and generate his own public and private key. The client therefore thinks it is communicating with the real server, when in fact it is communicating with the pirate.
The hacker will then decrypt and recover the client's message before pretending to be the client, re-encrypting the message with the real server's public key and sending it to the server so as not to arouse suspicion.
To get a local copy up and running follow these simple steps.
You need to install Python, that can be done here
- Clone the repo
git clone https://github.com/KursK-sys/Secure-Http-Server.git cd Secure-Http-Server - Install Python packages
pip install -r requirements.txt
git clone https://github.com/KursK-sys/Secure-Http-Server.git
pkg install python
pip install -r requirements.txt
cd Secure-Http-Server
Run the server.py on server side and client.py on client side.
There is an graphic interface, with two user entry zones, one for the server IP address and the other for the port.
- Default: 127.0.0.1 and 80 You can then start the server by click on the button and see all events in textbox.
In first you need to set correct server IP and port in the code. Default: 127.0.0.1 and 80 Type a message in client and see it in server.py in the logs textbox made for it.
MIT License
Copyright (c) 2022 Elias
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.