Add WebSocket auth — JWT token validation on WS upgrade handshake

- websocket.nim: check Authorization Bearer token before WebSocket upgrade
- httpserver.nim: pass config + jwtSecret to WsServer

src/barabadb/core/httpserver.nim

@@ -42,11 +42,11 @@ proc newHttpServer*(config: BaraConfig): HttpServer =
   let db = newLSMTree(dataDir)
   let ctx = newExecutionContext(db)
   ctx.txnManager = newTxnManager()
-  let ws = newWsServer()
+  let secret = if config.jwtSecret.len > 0: config.jwtSecret else: "baradb-default-secret-change-in-production!"
+  let ws = newWsServer(config, secret)
   ctx.onChange = proc(ev: ChangeEvent) =
     let msg = $ev.kind & " " & ev.table
     asyncCheck ws.broadcastToTable(ev.table, msg)
-  let secret = if config.jwtSecret.len > 0: config.jwtSecret else: "baradb-default-secret-change-in-production!"
   HttpServer(config: config, running: false, db: db, ctx: ctx,
              secretKey: secret,
              metrics: Metrics(), ws: ws)

src/barabadb/core/websocket.nim

@@ -5,6 +5,8 @@ import std/strutils
 import std/tables
 import std/base64
 import std/sets
+import config
+import jwt as jwtlib
 
 type
   WsFrame = object
@@ -24,11 +26,14 @@ type
     clients*: Table[int, WsClient]
     nextId: int
     running: bool
+    config*: BaraConfig
+    secretKey*: string
     onInsert*: proc (table, key, value: string) {.closure.}
     onDelete*: proc (table, key: string) {.closure.}
 
-proc newWsServer*(): WsServer =
+proc newWsServer*(cfg: BaraConfig = defaultConfig(), secret: string = ""): WsServer =
-  WsServer(clients: initTable[int, WsClient](), nextId: 1, running: false)
+  WsServer(clients: initTable[int, WsClient](), nextId: 1, running: false,
+           config: cfg, secretKey: secret)
 
 # ----------------------------------------------------------------------
 # WebSocket frame encoding/decoding (RFC 6455)
@@ -270,6 +275,25 @@ proc handleConnection(server: WsServer, client: AsyncSocket) {.async.} =
     client.close()
     return
 
+  # Auth check
+  if server.config.authEnabled:
+    let authHeader = headers.getOrDefault("authorization", "")
+    if authHeader.len == 0 or not authHeader.startsWith("Bearer "):
+      await client.send("HTTP/1.1 401 Unauthorized\r\n\r\n")
+      client.close()
+      return
+    let tokenStr = authHeader[7..^1]
+    try:
+      let token = tokenStr.toJWT()
+      if not token.verify(server.secretKey, HS256):
+        await client.send("HTTP/1.1 401 Unauthorized\r\n\r\n")
+        client.close()
+        return
+    except:
+      await client.send("HTTP/1.1 401 Unauthorized\r\n\r\n")
+      client.close()
+      return
+
   let acceptKey = computeAcceptKey(wsKey)
 
   var response = "HTTP/1.1 101 Switching Protocols\r\n"