Added shebangs

geändert:       client/client.py
	geändert:       lib/terminal_table.py
	umbenannt:      server/main.py -> server/server.py

server/server.py

@@ -0,0 +1,93 @@
+#!/usr/bin/env python3
+
+import sys
+import os
+sys.path.append(os.getcwd())
+import asyncio
+from lib.crypto_utils import (
+    generate_keypair,
+    serialize_public_key,
+    deserialize_public_key,
+    derive_aes_key,
+)
+from lib.jebp_utils import sendmsg, readmsg, validate_cert, InvalidCertificateError
+from cryptography.hazmat.primitives.ciphers.aead import AESGCM
+from cryptography.hazmat.primitives import serialization
+from cryptography.hazmat.backends import default_backend
+from cryptography import x509
+import base64
+import dbm
+import hashlib
+
+
+HOST = "0.0.0.0"
+PORT = 8888
+VERSION = 'jebp 1.0'
+CERT_FILE = 'server/sec/server.crt.pem'
+CLIENT_CERT_ISSUER_NAME = 'jCloudCA-Root-CA'
+
+async def handle_client(reader: asyncio.StreamReader, writer: asyncio.StreamWriter):
+    addr = writer.get_extra_info('peername')
+    print(f'Connected to {addr}')
+
+
+    await sendmsg(VERSION, writer)
+    
+    # BEGIN ENCRYPTION HANDSHAKE
+
+    server_priv, server_pub = generate_keypair()
+
+    client_pub_bytes = await readmsg(reader)
+    client_pub = deserialize_public_key(client_pub_bytes)
+
+    await sendmsg(serialize_public_key(server_pub), writer)
+
+    aes_key = derive_aes_key(server_priv, client_pub)
+    aesgcm = AESGCM(aes_key)
+
+    client_nonce = await readmsg(reader)
+
+    server_nonce = os.urandom(12)
+    await sendmsg(server_nonce, writer)
+
+    await sendmsg(await readmsg(reader, aesgcm, client_nonce), writer)
+
+
+    # BEGIN SERVER AUTHENTICATION HANDSHAKE
+
+
+    await readmsg(reader)
+    with open(CERT_FILE, 'rb') as certfile:
+        cert_data = certfile.read()
+        certfile.close()
+
+    await sendmsg(base64.b64decode(cert_data.replace(b'-----BEGIN CERTIFICATE-----', b'').replace(b'-----END CERTIFICATE-----', b'').strip()), writer, aesgcm, server_nonce)
+
+
+    # BEGIN CLIENT AUTHENTICATION HANDSHAKE
+
+    cert = x509.load_der_x509_certificate(await readmsg(reader, aesgcm, client_nonce))
+    key_hash = hashlib.sha256(cert.public_key().public_bytes(encoding=serialization.Encoding.DER, format=serialization.PublicFormat.SubjectPublicKeyInfo)).digest()
+    with dbm.open('server/config/clients/fingerprints', 'c') as db:
+        if key_hash not in db.keys():
+            raise InvalidCertificateError('client not known')
+        if not validate_cert(cert, db[key_hash].decode(), CLIENT_CERT_ISSUER_NAME):
+            raise InvalidCertificateError('client certificate not trusted')
+
+    print('Client authenticated')
+
+    writer.close()
+    await writer.wait_closed()
+
+
+async def main():
+    server = await asyncio.start_server(handle_client, HOST, PORT)
+    addr = ', '.join(str(sock.getsockname()) for sock in server.sockets)
+    print(f'Listening on {addr}')
+
+    async with server:
+        await server.serve_forever()
+
+
+if __name__ == '__main__':
+    asyncio.run(main())