Add send message function

ressenger_client.py

@@ -11,6 +11,17 @@ Address = str
 # Default timeout for socket operations (seconds)
 _DEFAULT_TIMEOUT = 10.0
 
+# Return codes
+SUCCESS = 0
+ERR_TYPE = 1                 # invalid data type (TypeError)
+ERR_PAYLOAD_TOO_LARGE = 2    # payload exceeds supported length (ValueError)
+ERR_SOCKET_ERROR = 3         # plain TCP connection error or timeout
+ERR_SEND_FAILED = 4          # failure while sending data
+ERR_SOCKS_MISSING = 5        # PySocks (socks) module not installed
+ERR_INVALID_SOCKS_PORT = 6   # I2P_SOCKS_PORT environment variable not an integer
+ERR_PROXY_CONNECTION = 7     # error connecting through SOCKS proxy (I2P)
+ERR_UNKNOWN = 8              # unknown/unexpected error
+
 
 def _prepare_payload(data: typing.Union[bytes, str]) -> bytes:
     """
@@ -37,7 +48,7 @@ def _pack_message(payload: bytes) -> bytes:
     return struct.pack("!I", length) + payload
 
 
-def send_data(data: typing.Union[bytes, str], addr: Address, port: int) -> None:
+def send_data(data: typing.Union[bytes, str], addr: Address, port: int) -> int:
     """
     Send a single length-prefixed message over plain TCP to (addr, port).
 
@@ -48,22 +59,37 @@ def send_data(data: typing.Union[bytes, str], addr: Address, port: int) -> None:
 
     Behaviour:
       - Connects, sends the framed message, then closes the socket.
-      - Raises built-in socket exceptions on failure.
-
-    Example:
-      send_data(b'hello', '192.0.2.1', 12345)
+      - Returns 0 on success, otherwise returns an error code.
     """
-    payload = _prepare_payload(data)
-    message = _pack_message(payload)
+    try:
+        payload = _prepare_payload(data)
+    except TypeError:
+        return ERR_TYPE
+    try:
+        message = _pack_message(payload)
+    except ValueError:
+        return ERR_PAYLOAD_TOO_LARGE
 
     # Create a TCP connection with a timeout
-    with socket.create_connection((addr, port), timeout=_DEFAULT_TIMEOUT) as sock:
-        # Ensure blocking mode for sendall
-        sock.setblocking(True)
-        sock.sendall(message)
+    try:
+        with socket.create_connection((addr, port), timeout=_DEFAULT_TIMEOUT) as sock:
+            # Ensure blocking mode for sendall
+            sock.setblocking(True)
+            try:
+                sock.sendall(message)
+            except (socket.timeout, OSError):
+                # Sending failed after connection
+                return ERR_SEND_FAILED
+    except (socket.timeout, OSError):
+        # Could not create connection (including DNS, connect, timeout)
+        return ERR_SOCKET_ERROR
+    except Exception:
+        return ERR_UNKNOWN
+
+    return SUCCESS
 
 
-def send_data_i2p(data: typing.Union[bytes, str], addr: Address, port: int) -> None:
+def send_data_i2p(data: typing.Union[bytes, str], addr: Address, port: int) -> int:
     """
     Send a single length-prefixed message to an I2P destination via a local i2pd SOCKS5 proxy.
 
@@ -76,33 +102,29 @@ def send_data_i2p(data: typing.Union[bytes, str], addr: Address, port: int) -> N
       - Uses PySocks (socks) to create a socket that speaks SOCKS5 to the local proxy.
       - Uses remote DNS resolution (rdns=True) so that the proxy resolves .i2p names.
       - Connects, sends the framed message, then closes the socket.
-      - Raises ImportError if PySocks is not installed.
-      - Raises socket or proxy-related exceptions on failure.
-
-    Environment variables:
-      - I2P_SOCKS_HOST (default '127.0.0.1')
-      - I2P_SOCKS_PORT (default '4447')
-
-    Example:
-      send_data_i2p(b'hello', 'abcd1234xxxxxxx.b32.i2p', 12345)
+      - Returns 0 on success, otherwise returns an error code.
     """
     try:
         import socks  # PySocks; license: MIT
-    except Exception as e:
-        raise ImportError(
-            "PySocks is required for send_data_i2p. "
-            "Install it with: pip install PySocks"
-        ) from e
+    except Exception:
+        return ERR_SOCKS_MISSING
 
-    payload = _prepare_payload(data)
-    message = _pack_message(payload)
+    try:
+        payload = _prepare_payload(data)
+    except TypeError:
+        return ERR_TYPE
+
+    try:
+        message = _pack_message(payload)
+    except ValueError:
+        return ERR_PAYLOAD_TOO_LARGE
 
     socks_host = os.environ.get("I2P_SOCKS_HOST", "127.0.0.1")
     socks_port_str = os.environ.get("I2P_SOCKS_PORT", "4447")
     try:
         socks_port = int(socks_port_str)
     except ValueError:
-        raise ValueError("I2P_SOCKS_PORT environment variable must be an integer")
+        return ERR_INVALID_SOCKS_PORT
 
     # Create a socksified socket. socks.socksocket has the same interface as socket.socket.
     s = socks.socksocket()
@@ -114,11 +136,27 @@ def send_data_i2p(data: typing.Union[bytes, str], addr: Address, port: int) -> N
         # Connect through the proxy to the I2P destination.
         # When rdns=True, the proxy will perform name resolution for .i2p addresses.
         s.connect((addr, port))
+    except (socket.timeout, OSError, Exception):
+        # Proxy connection / resolution failed
+        try:
+            s.close()
+        except Exception:
+            pass
+        return ERR_PROXY_CONNECTION
+
+    try:
         # Ensure blocking mode for sendall
         s.setblocking(True)
-        s.sendall(message)
+        try:
+            s.sendall(message)
+        except (socket.timeout, OSError):
+            return ERR_SEND_FAILED
+    except Exception:
+        return ERR_UNKNOWN
     finally:
         try:
             s.close()
         except Exception:
             pass
+
+    return SUCCESS

ressenger_common.py

@@ -1,9 +1,6 @@
 #!/usr/bin/python3
-import ressenger_cryptography, ressenger_exceptions
-import pickle, pathlib
-
-# class Contact():
-#     def __init__(self, nickname, b32address, pub_enc, pub_sig):
+import ressenger_cryptography, ressenger_exceptions, ressenger_client
+import pickle, pathlib, time
 
 def load_user(password, username='default'):
     user_path=pathlib.Path(f'~/.ressenger/{username}').expanduser()
@@ -21,3 +18,19 @@ def dump_user(password, user, username='default'):
     else:
         with open(user_path, 'wb') as file:
             file.write(ressenger_cryptography.encrypt_bytes(pickle.dumps(user, protocol=pickle.HIGHEST_PROTOCOL), password))
+
+def send_message(text, destination_addr, destination_port, enc_pub_key, sig_pri_key, sig_pub_key):
+    data={'type':'text', 'sent_time'=time.time_ns(), 'data':{'content':text}}
+    data_encrypted, data_signature=ressenger_cryptography.encrypt(pickle.dumps(data, protocol=pickle.HIGHEST_PROTOCOL), enc_pub_key, sig_pri_key)
+    packet={'data':data_encrypted, 'sig':data_signature, 'enc_pub':enc_pub_key, 'sig_pub':sig_pub_key}
+    errorno=ressenger_client.send_data_i2p(pickle.dumps(packet, protocol=pickle.HIGHEST_PROTOCOL), destination_addr, destination_port)
+    event={'type':'sent', 'data':data, 'dest':{'addr':destination_addr, 'port':destination_port}, 'errorno':errorno}
+    return event
+
+def send_file(filename, filebytes, destination_addr, destination_port, enc_pub_key, sig_pri_key, sig_pub_key)
+    data={'type':'file', 'sent_time'=time.time_ns(), 'data':{'content':filebytes, 'filename':filename}}
+    data_encrypted, data_signature=ressenger_cryptography.encrypt(pickle.dumps(data, protocol=pickle.HIGHEST_PROTOCOL), enc_pub_key, sig_pri_key)
+    packet={'data':data_encrypted, 'sig':data_signature, 'enc_pub':enc_pub_key, 'sig_pub':sig_pub_key}
+    errorno=ressenger_client.send_data_i2p(pickle.dumps(packet, protocol=pickle.HIGHEST_PROTOCOL), destination_addr, destination_port)
+    event={'type':'sent', 'data':data, 'dest':{'addr':destination_addr, 'port':destination_port}, 'errorno':errorno}
+    return event

ressenger_cryptography.py

@@ -185,7 +185,7 @@ def decrypt(encrypted_bytes: bytes, decryption_private_key_pem: bytes, verificat
 #     # generate sender signing keypair (sender)
 #     priv_sig, pub_sig = generate_keypair()
 #
-#     message = b"I love Ruby!"
+#     message = b"I love C!"
 #     out = encrypt(message, pub_enc, priv_sig)
 #     if out is None:
 #         raise SystemExit("Encryption failed")

ressenger_initialisation.py

@@ -23,4 +23,4 @@ def initialise(password, b32address, username='default', port=5273, nick='John D
     enc_pri, enc_pub=ressenger_cryptography.generate_keypair()
     sig_pri, sig_pub=ressenger_cryptography.generate_keypair()
     with open(user_path, 'wb') as file:
-        file.write(ressenger_cryptography.encrypt_bytes(pickle.dumps({'port':port, 'b32address':b32address, 'enc_pri':enc_pri, 'enc_pub':enc_pub, 'sig_pri':sig_pri, 'sig_pub':sig_pub, 'keyring':[], 'events':{}, 'contacts':{}}, protocol=pickle.HIGHEST_PROTOCOL), password))
+        file.write(ressenger_cryptography.encrypt_bytes(pickle.dumps({'port':port, 'b32address':b32address, 'enc_pri':enc_pri, 'enc_pub':enc_pub, 'sig_pri':sig_pri, 'sig_pub':sig_pub, 'contacts':{}, 'events':{}}, protocol=pickle.HIGHEST_PROTOCOL), password))

ressenger_server.py

@@ -1,17 +1,4 @@
-#!/usr/bin/env python3
-"""
-TCP server that receives binary blobs and persists them to a cache file.
-This variant ensures the cache file is removed on shutdown (where possible).
-
-Behaviour:
- - Always start with a fresh, empty CACHE (do NOT load existing file).
- - Use a dedicated CacheWriter thread to debounce and atomically write CACHE.
- - On exit (signals, KeyboardInterrupt, normal interpreter exit) stop writer and remove cache file.
-Note: SIGKILL (kill -9) and sudden power loss cannot be trapped; cleanup cannot run then.
-"""
-
-# English comments throughout (British English spelling).
-
+#!/usr/bin/python3
 import socket
 import threading
 import struct
@@ -226,7 +213,7 @@ def run_server(port: int):
         CACHE_PATH.parent.mkdir(parents=True, exist_ok=True)
         with cache_lock:
             atomic_dump(CACHE, CACHE_PATH)
-        print("Initialised fresh empty CACHE on disk (existing file not loaded).")
+        print("Initialised fresh empty CACHE on disk.")
     except Exception:
         print("Failed to initialise cache file on disk")
         traceback.print_exc()

ressenger_user.py

@@ -1 +1,3 @@
 #!/usr/bin/python3
+import ressenger_common
+