add draft code

draft_code/modwebsocket_test.py

@@ -0,0 +1,39 @@
+#import network
+import socket
+import ubinascii
+from websocket import websocket
+
+
+# Create and connect socket
+sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+#sock.connect(('echo.websocket.org', 80))
+sock.connect(socket.getaddrinfo('echo.websocket.org', 80)[0][-1])
+#getaddrinfo('localhost', 5000)[0][-1]
+
+# Perform WebSocket handshake
+key = ubinascii.b2a_base64(b'random_bytes_here').strip()
+handshake = (
+    'GET / HTTP/1.1\r\n'
+    'Host: echo.websocket.org\r\n'
+    'Upgrade: websocket\r\n'
+    'Connection: Upgrade\r\n'
+    'Sec-WebSocket-Key: {}\r\n'
+    'Sec-WebSocket-Version: 13\r\n'
+    '\r\n'
+).format(key.decode())
+sock.send(handshake.encode())
+response = sock.recv(1024).decode()
+print(f"reponse: {response}")
+if '101 Switching Protocols' not in response:
+    raise Exception('Handshake failed')
+
+# Create WebSocket object
+ws = websocket(sock, True)
+
+# Send and receive data
+ws.write('Hello, WebSocket!')
+data = ws.read(1024)
+print('Received:', data)
+
+# Close connection
+ws.close()

draft_code/secp256k1.py

@@ -0,0 +1,51 @@
+import secp256k1
+import hashlib
+from binascii import hexlify
+
+def secp256k1_example():
+    """Usage example for secp256k1 usermodule"""
+
+    # randomize context from time to time
+    # - it helps against sidechannel attacks
+    # secp256k1.context_randomize(os.urandom(32))
+
+    # some random secret key
+    secret = hashlib.sha256(b"secret key").digest()
+
+    print("Secret key:", hexlify(secret).decode())
+
+    # Makes sense to check if secret key is valid.
+    # It will be ok in most cases, only if secret > N it will be invalid
+    if not secp256k1.ec_seckey_verify(secret):
+        raise ValueError("Secret key is invalid")
+
+    # computing corresponding pubkey
+    pubkey = secp256k1.ec_pubkey_create(secret)
+
+    # serialize the pubkey in compressed format
+    sec = secp256k1.ec_pubkey_serialize(pubkey, secp256k1.EC_COMPRESSED)
+    print("Public key:", hexlify(sec).decode())
+ 
+    # this is how you parse the pubkey
+    pubkey = secp256k1.ec_pubkey_parse(sec)
+
+    # Signature generation:
+ 
+    # hash of the string "hello"
+    msg = hashlib.sha256(b"hello").digest()
+    # signing
+    sig = secp256k1.ecdsa_sign(msg, secret)
+ 
+    # serialization
+    der = secp256k1.ecdsa_signature_serialize_der(sig)
+
+    print("Signature:", hexlify(der).decode())
+
+    # verification
+    if secp256k1.ecdsa_verify(sig, msg, pubkey):
+        print("Signature is valid")
+    else:
+        printf("Invalid signature")
+
+if __name__ == '__main__':
+    secp256k1_example()