From c3dbdefc3f73e64696609156a367d9ae130ac0fc Mon Sep 17 00:00:00 2001
From: Bartoszkk <Bartosz.michalak@epitech.eu>
Date: Mon, 1 Jul 2024 15:04:24 +0200
Subject: [PATCH] add of compression encryptino decryption process

---
 encryption/example.bin      |  1 +
 encryption/main.py          | 96 +++++++++++++++++++++++++++++++++++++
 encryption/requirements.txt |  1 +
 3 files changed, 98 insertions(+)
 create mode 100644 encryption/example.bin
 create mode 100755 encryption/main.py
 create mode 100644 encryption/requirements.txt

diff --git a/encryption/example.bin b/encryption/example.bin
new file mode 100644
index 0000000..8a5022e
--- /dev/null
+++ b/encryption/example.bin
@@ -0,0 +1 @@
+Ϩ-���o��
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\ No newline at end of file
diff --git a/encryption/main.py b/encryption/main.py
new file mode 100755
index 0000000..028f0e0
--- /dev/null
+++ b/encryption/main.py
@@ -0,0 +1,96 @@
+#!/usr/bin/env python3
+
+import sys
+from ffmpy import FFmpeg
+from cryptography.hazmat.primitives.asymmetric import ec
+from cryptography.hazmat.primitives import hashes
+from cryptography.hazmat.primitives.kdf.hkdf import HKDF
+from cryptography.hazmat.primitives.ciphers import Cipher, algorithms, modes
+from cryptography.hazmat.primitives import serialization
+from cryptography.hazmat.primitives import padding
+from cryptography.hazmat.backends import default_backend
+import os
+import subprocess
+
+private_key = ec.generate_private_key(ec.SECP256R1(), default_backend())
+public_key = private_key.public_key()
+public_key_bytes = public_key.public_bytes(
+    encoding=serialization.Encoding.PEM,
+    format=serialization.PublicFormat.SubjectPublicKeyInfo
+)
+
+
+
+def encrypt_bitstream(bitstream, peer_public_key_bytes):
+    peer_public_key = serialization.load_pem_public_key(peer_public_key_bytes, backend=default_backend())
+    shared_key = private_key.exchange(ec.ECDH(), peer_public_key)
+    derived_key = HKDF(
+        algorithm=hashes.SHA256(),
+        length=32,
+        salt=None,
+        info=b'handshake data',
+        backend=default_backend()
+    ).derive(shared_key)
+    iv = os.urandom(16)
+    cipher = Cipher(algorithms.AES(derived_key), modes.CBC(iv), backend=default_backend())
+    encryptor = cipher.encryptor()
+    padder = padding.PKCS7(algorithms.AES.block_size).padder()
+    padded_data = padder.update(bitstream) + padder.finalize()
+    ciphertext = encryptor.update(padded_data) + encryptor.finalize()
+    return iv + ciphertext
+
+
+
+def decrypt_bitstream(ciphertext, peer_public_key_bytes):
+    peer_public_key = serialization.load_pem_public_key(peer_public_key_bytes, backend=default_backend())
+    shared_key = private_key.exchange(ec.ECDH(), peer_public_key)
+    derived_key = HKDF(
+        algorithm=hashes.SHA256(),
+        length=32,
+        salt=None,
+        info=b'handshake data',
+        backend=default_backend()
+    ).derive(shared_key)
+    iv = ciphertext[:16]
+    actual_ciphertext = ciphertext[16:]
+    cipher = Cipher(algorithms.AES(derived_key), modes.CBC(iv), backend=default_backend())
+    decryptor = cipher.decryptor()
+    padded_data = decryptor.update(actual_ciphertext) + decryptor.finalize()
+    unpadder = padding.PKCS7(algorithms.AES.block_size).unpadder()
+    data = unpadder.update(padded_data) + unpadder.finalize()
+    return data
+
+
+
+def process_audio(input_wav):
+
+    process = subprocess.Popen(
+        ['ffmpeg', '-i', input_wav, '-ar', '8000', '-b:a', '128k', '-f', 'mp3', 'pipe:1'],
+        stdout=subprocess.PIPE,
+        stderr=subprocess.PIPE
+    )
+    return process.stdout.read()
+
+
+def main():
+    input_wav = 'CantinaBand60.wav'
+
+    with open(input_wav, 'rb') as f:
+        original_bitstream = f.read()
+
+    processed_bitstream = process_audio(input_wav)
+
+    print("Original WAV bitstream length:", len(original_bitstream))
+    print("Processed MP3 bitstream length:", len(processed_bitstream))
+
+    chunk_size = 1024
+    for i in range(0, len(processed_bitstream), chunk_size):
+        chunk = processed_bitstream[i:i + chunk_size]
+        ciphertext = encrypt_bitstream(chunk, public_key_bytes)
+        decrypted_chunk = decrypt_bitstream(ciphertext, public_key_bytes)
+        with open('output.mp3', 'ab') as f:
+            f.write(decrypted_chunk)
+
+
+if __name__ == "__main__":
+    main()
diff --git a/encryption/requirements.txt b/encryption/requirements.txt
new file mode 100644
index 0000000..488c3aa
--- /dev/null
+++ b/encryption/requirements.txt
@@ -0,0 +1 @@
+cryptography
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