server code with basic account stuff

2026-07-28 18:31:54 +02:00
parent 6eb37f137c
commit 4a5ff08afc
4 changed files with 497 additions and 0 deletions
@@ -0,0 +1,137 @@
+#!/usr/bin/env python
+
+import asyncio
+import json, random, re, math, time, traceback
+from websockets.asyncio.server import serve
+
+from db import Database
+
+
+userdb = Database("users")
+userdb.createTable("NAMES",{"id":"int","name":"string","creation_date":"int","last_login":"int"})
+userdb.createTable("PASSWORDS",{"id":"int","sum":"string"})
+
+def makeUserID() -> int:
+    count = userdb.rowAmount("NAMES")
+    digits = max(4,1+int(math.log10(10+count)))
+
+    uid=0
+    while uid==0 or userdb.hasPK("NAMES","id",uid) or userdb.hasPK("PASSWORDS","id",uid):
+        uid = random.randint(0,(10**digits)-1) & 0x7FFFFFFFFFFFFFFF
+    return uid
+
+def isValidUsername(name) -> bool:
+    pattern = re.compile("^[a-z][a-z0-9-_]*")
+    match = pattern.match(name)
+    if match==None: return False
+    return match.start()==0 and match.end()==len(name)
+
+def isValidChecksum(cs) -> bool:
+    if len(cs)!=32: return False
+    pattern = re.compile("^[0-9a-f]*")
+    match = pattern.match(cs)
+    if match==None: return False
+    return match.start()==0 and match.end()==len(cs)
+
+
+def response(msg,**kwargs) -> str:
+    return json.dumps({"type":"response","response":msg,**kwargs})
+
+def clientError(msg,**kwargs) -> str:
+    return json.dumps({"type":"error","error":msg,"server":False,**kwargs})
+
+def serverError(msg,**kwargs) -> str:
+    print(f"Server error: {msg}")
+    return json.dumps({"type":"error","error":msg,"server":True,**kwargs})
+
+sessionUsers = {}
+
+async def handleCommand(ws,cmd):
+    global sessionUsers
+    print(f"recieved command: {cmd} (from {id(ws)})")
+    if not "type" in cmd:
+        return await ws.send(clientError("Malformed command"))
+    if id(ws) in sessionUsers:
+        uid = sessionUsers[id(ws)]
+    match cmd["type"]:
+        case "ping":
+            return await ws.send(response("Pong!"))
+        case "createuser":
+            uid = makeUserID()
+            name = cmd["name"]
+            name = name.lower()
+            if not isValidUsername(name):
+                return await ws.send(clientError("Username is not valid."))
+            if len(userdb.select("SELECT * FROM NAMES WHERE name = ?",(name,)))>0:
+                return await ws.send(clientError(f"The username '{name}' is already taken."))
+            psum = cmd["pass"]
+            psum = psum.lower()
+            if not isValidChecksum(psum):
+                return await ws.send(clientError("Recieved password has not been correctly checksummed."))
+            create = time.time()
+            userdb.insertRow("NAMES",{"id":uid,"name":cmd["name"],"creation_date":create,"last_login":create})
+            userdb.insertRow("PASSWORDS",{"id":uid,"sum":psum})
+            return await ws.send(response({"uid":uid}))
+
+        case "login":
+            if id(ws) in sessionUsers:
+                return await ws.send(clientError("You are already logged in."))
+            name = cmd["name"]
+            psum = cmd["pass"]
+            if not isValidUsername(name):
+                return await ws.send(clientError("Username is not valid."))
+            res = userdb.findRow("NAMES","name = ?",(name,))
+            if res==None:
+                return await ws.send(clientError("Invalid username or password."))
+            uid = res["id"]
+            if not isValidChecksum(psum):
+                return await ws.send(clientError("Recieved password has not been correctly checksummed."))
+            dbsum = userdb.rowFromPK("PASSWORDS","id",uid)["sum"]
+            if psum.lower() != dbsum.lower():
+                return await ws.send(clientError("Invalid username or password."))
+            print(f"session {id(ws)} has logged in as {name} ({uid})")
+            sessionUsers[id(ws)] = uid
+            userdb.updateFromPK("NAMES","id",uid,{"last_login":time.time()})
+            return await ws.send(response("success"))
+
+        case "logout":
+            if not id(ws) in sessionUsers:
+                return await ws.send(clientError("You are already logged out."))
+            del sessionUsers[id(ws)]
+            return await ws.send(response("success"))
+
+        case "status":
+            if not id(ws) in sessionUsers:
+                return await ws.send(response({"login":False}))
+            name = userdb.rowFromPK("NAMES","id",uid)["name"]
+            return await ws.send(response({"login":True,"uid":uid,"name":name}))
+
+        case _:
+            return await ws.send(clientError(f"Command '{cmd["type"]}' does not exist."))
+
+
+async def serveClient(ws):
+    print("serve client",id(ws))
+    await ws.send(json.dumps({"type":"connected"}))
+    while True:
+        try:
+            cmdtxt = await ws.recv()
+            if type(cmdtxt)==bytes: cmdtxt=cmdtxt.decode("utf8")
+            if type(cmdtxt)!=str: continue
+            cmd = json.loads(cmdtxt)
+            try:
+                await handleCommand(ws,cmd)
+            except Exception as e:
+                traceback.print_exception(e)
+                await ws.send(serverError(f"Cannot process command ({cmd["type"]})"))
+        except Exception as e:
+            traceback.print_exception(e)
+            await ws.send(serverError("Cannot process JSON."))
+
+async def main():
+    async with serve(serveClient, "", 30341) as server:
+        await server.serve_forever()
+
+if __name__ == "__main__":
+    print("now serving")
+    asyncio.run(main())