Merge pull request #2864 from yueguobin/fix/console-ws-ticket

fix: issue short-lived access tickets instead of JWTs in MCP tools

docs/features/mcp-service.md

@@ -439,7 +439,7 @@ sequenceDiagram
 
 ### Console WebSocket
 
-The `node_console` tool returns a WebSocket URL for connecting to a node's console. The URL includes a short-lived JWT (10 min) — reconnect if it expires. This endpoint is protocol-agnostic — it works for **telnet**, **ssh**, and **vnc** console types alike. The WebSocket simply proxies raw byte streams between the client and the compute node; protocol negotiation (e.g. SSH key exchange) happens on the compute side.
+The `node_console` tool returns a WebSocket URL for connecting to a node's console. The URL includes a short-lived **access ticket** (10 min) — a short random string (`gns3t_…`, 22 chars) minted server-side and bound to that node's console endpoints. `link_capture_download` uses the same kind of ticket bound to one exact resource path instead of embedding a Bearer JWT in the returned curl command. Tickets replaced the long JWTs previously embedded in these URLs/commands: LLM clients retyping them into shell commands reliably corrupted a ~200-char JWT, while a short ticket survives copying. Re-request the URL when the ticket expires (logging out also invalidates outstanding tickets). This endpoint is protocol-agnostic — it works for **telnet**, **ssh**, and **vnc** console types alike. The WebSocket simply proxies raw byte streams between the client and the compute node; protocol negotiation (e.g. SSH key exchange) happens on the compute side.
 
 The WebSocket URL is constructed using the server's `_server_url()`, which resolves the host as follows:
 
@@ -454,11 +454,11 @@ When `Server.host` is `0.0.0.0` (listen on all interfaces), the MCP server disco
 
 If the configured host is already a specific IP or hostname (not `0.0.0.0`), it is used directly in the URL without modification.
 
-Use `websocat` to connect from the command line:
+Use `websocat` to connect from the command line (use the `command` returned by `node_console` verbatim — never reconstruct the URL by hand):
 
 ```bash
 # The host in the URL is automatically resolved to a reachable address
-websocat ws://192.168.1.3:3080/v3/projects/{project_id}/nodes/{node_id}/console/ws?token=<jwt>
+websocat ws://192.168.1.3:3080/v3/projects/{project_id}/nodes/{node_id}/console/ws?token=<console_ticket>
 ```
 
 ### Source Files

docs/features/vnc-websocket-console.md

@@ -58,7 +58,7 @@ graph LR
 **URL**: `ws://{controller_host}:{port}/v3/projects/{project_id}/nodes/{node_id}/console/vnc?token={jwt_token}`
 
 **Authentication**:
-- JWT token via query parameter
+- JWT token via query parameter, **or** a short-lived console ticket (`gns3t_…`, minted per node by the `node_console` MCP tool, valid 10 min, bound to this node's console endpoints)
 - User must have `Node.Console` privilege
 
 **WebSocket Subprotocols**:
@@ -179,7 +179,7 @@ sequenceDiagram
 
 1. **Authentication**:
    - JWT token validation via `has_privilege_on_websocket("Node.Console")` dependency
-   - Token passed as query parameter: `?token={jwt}`
+   - Token passed as query parameter: `?token={jwt}`, or a console ticket (`gns3t_…`) redeemable only on the node it was minted for
 
 2. **Authorization**:
    - RBAC privilege check: `Node.Console`

gns3server/agent/gns3_copilot/gns3_client/api_handlers.py

@@ -53,7 +53,8 @@ from concurrent.futures import ThreadPoolExecutor
 import hashlib
 import logging
 
-from gns3server.services import auth_service
+from gns3server.services import access_ticket_service
+from gns3server.services.access_tickets import DEFAULT_TICKET_TTL
 
 from gns3server.agent.gns3_copilot.gns3_client.connector import Gns3Connector
 
@@ -416,12 +417,21 @@ def get_node_console_info_handler(params: dict[str, Any], gns3_ctx: dict[str, An
     node = conn.http_call("get", f"{conn.base_url}/projects/{project_id}/nodes/{node_id}").json()
 
     console_type = node.get("console_type", "unknown")
-    # Short-lived JWT for the WebSocket URL (10 min)
+    # Short-lived console ticket (10 min, multi-use, bound to this node's
+    # console endpoints). Deliberately a short random string instead of a JWT:
+    # LLM clients retype this URL into shell commands and reliably corrupted
+    # the ~200-char JWT previously embedded here (dropped header segment →
+    # "Missing 'alg' value in header" on the server).
     username = gns3_ctx.get("jwt_username")
-    ws_token = auth_service.create_access_token(username, token_version=gns3_ctx.get("jwt_token_version", 0), expires_in=10) if username else None
+    ticket = access_ticket_service.mint(
+        username,
+        token_version=gns3_ctx.get("jwt_token_version", 0),
+        project_id=project_id,
+        node_id=node_id,
+    ) if username else None
     raw_url = f"{gns3_ctx['server_url']}/v3/projects/{project_id}/nodes/{node_id}/console/ws"
-    if ws_token:
-        raw_url += f"?token={ws_token}"
+    if ticket:
+        raw_url += f"?token={ticket}"
     # Convert http scheme to ws for direct websocat usage
     ws_url = raw_url.replace("https://", "wss://").replace("http://", "ws://")
 
@@ -432,14 +442,15 @@ def get_node_console_info_handler(params: dict[str, Any], gns3_ctx: dict[str, An
         "ws_url": ws_url,
         "command": f"websocat -t --no-close {ws_url}",
     }
-    if ws_token:
+    if ticket:
         # Fingerprint of the minted token: compare it against what actually reached the
         # server (logged on WebSocket auth rejection) to detect copy corruption, and
         # re-request the URL once token_ttl_seconds has elapsed.
-        result["token_sha256_prefix"] = hashlib.sha256(ws_token.encode()).hexdigest()[:8]
-        result["token_ttl_seconds"] = 600
-    if console_type in ("vnc",):
-        result["vnc_url"] = f"/v3/projects/{project_id}/nodes/{node_id}/console/vnc?token={gns3_ctx['jwt_token']}"
+        result["token_sha256_prefix"] = hashlib.sha256(ticket.encode()).hexdigest()[:8]
+        result["token_ttl_seconds"] = DEFAULT_TICKET_TTL
+    if console_type in ("vnc",) and ticket:
+        # Same node binding covers the vnc endpoint (identical path params)
+        result["vnc_url"] = f"/v3/projects/{project_id}/nodes/{node_id}/console/vnc?token={ticket}"
     return result
 
 
@@ -848,34 +859,36 @@ def download_capture_file_handler(params: dict[str, Any], gns3_ctx: dict[str, An
     if not project_id:
         return {"error": "project_id is required"}
     username = gns3_ctx.get("jwt_username")
-    download_token = auth_service.create_access_token(username, token_version=gns3_ctx.get("jwt_token_version", 0), expires_in=10) if username else None
+    token_version = gns3_ctx.get("jwt_token_version", 0)
+
+    def _download(link_id: str) -> dict[str, Any]:
+        # short-lived ticket bound to this exact download path — LLM clients
+        # retyping curl commands corrupted the long Bearer JWT this used to embed
+        path = f"/v3/projects/{project_id}/links/{link_id}/capture/file"
+        url = f"{gns3_ctx['server_url']}{path}"
+        ticket = access_ticket_service.mint(username, token_version=token_version, path=path) if username else None
+        if ticket:
+            url += f"?token={ticket}"
+        entry = {"link_id": link_id, "download_url": url}
+        if ticket:
+            entry["curl_command"] = f"curl -L -o capture_{link_id}.pcap '{url}'"
+        return entry
 
     link_ids = params.get("link_ids")
     if link_ids:
         if not isinstance(link_ids, list):
             return {"error": "link_ids must be a list"}
-        results = []
-        for lid in link_ids:
-            url = f"{gns3_ctx['server_url']}/v3/projects/{project_id}/links/{lid}/capture/file"
-            entry = {"link_id": lid, "download_url": url}
-            if download_token:
-                cmd = f"curl -L -o capture_{lid}.pcap -H 'Authorization: Bearer {download_token}' '{url}'"
-                entry["curl_command"] = cmd
-            results.append(entry)
-        return {"downloads": results, "count": len(results), "note": "Files are in pcap format. Links include a 10-minute token."}
+        results = [_download(lid) for lid in link_ids]
+        return {"downloads": results, "count": len(results), "note": "Files are in pcap format. URLs include a 10-minute ticket."}
 
     link_id = params.get("link_id")
     if not link_id:
         return {"error": "link_id or link_ids is required"}
-    download_url = f"{gns3_ctx['server_url']}/v3/projects/{project_id}/links/{link_id}/capture/file"
-    result = {
-        "link_id": link_id,
-        "download_url": download_url,
-        "note": "The file is in pcap format and can be analyzed with Wireshark or tcpdump.",
-    }
-    if download_token:
-        result["curl_command"] = f"curl -L -o capture.pcap -H 'Authorization: Bearer {download_token}' '{download_url}'"
-        result["note"] += " The download link includes a 10-minute token."
+    result = _download(link_id)
+    result["note"] = "The file is in pcap format and can be analyzed with Wireshark or tcpdump."
+    if "curl_command" in result:
+        result["curl_command"] = f"curl -L -o capture.pcap '{result['download_url']}'"
+        result["note"] += " The download URL includes a 10-minute ticket."
     return result
 
 

gns3server/agent/mcp/__init__.py

@@ -557,21 +557,19 @@ async def node_console(
 ) -> list[dict[str, Any]]:
     """Get WebSocket console connection info for a node.
 
-    Returns the WebSocket URL, console type (telnet/ssh/vnc), and other
-    connection details needed to interact with a node's console via WebSocket.
-    The URL includes a short-lived JWT (10 min) — reconnect if it expires.
+    Returns the console type (telnet/ssh/vnc) and a ready-to-run websocat
+    command with a short-lived access token (10 min) already embedded.
 
-    Complete workflow:
-      1. Call this tool with project_id and node_id to get the WebSocket URL
-      2. Connect to the returned URL using websocat in text mode (-t):
-         > websocat -t --no-close "ws://<your-gns3-server-host>:3080/v3/projects/{project_id}/nodes/{node_id}/console/ws?token={jwt_token}"
-      3. Send device commands with \\r\\n line endings via heredoc:
-         > websocat -t --no-close "ws://..." <<< $'\\r\\nenable\\r\\nshow version\\r\\nexit\\r\\n'
-      4. Receive response: websocat receives and displays device output
-         Use 'timeout' to avoid connection hanging:
-         > timeout 10 websocat -t --no-close "ws://..." <<< $'commands\\r\\n'
+    IMPORTANT — copy the returned values EXACTLY:
+      - Run the returned "command" string verbatim; it already contains the
+        full URL with token. NEVER construct or edit the URL yourself, and
+        NEVER copy the token by hand — a mistyped token is rejected.
+      - The token expires after token_ttl_seconds (10 min): call this tool
+        again to get a fresh one; do not reuse an old URL.
+
+    Sending device commands after connecting:
+      > timeout 10 websocat -t --no-close "ws://..." <<< $'\\r\\nenable\\r\\nshow version\\r\\nexit\\r\\n'
 
-    Key points:
       - Use \\r\\n (not \\n) to match console protocol line endings
       - Use $'...' format for escape sequences in bash
       - --no-close keeps the WebSocket open after stdin (heredoc) hits EOF, so
@@ -1011,7 +1009,18 @@ async def link_capture_download(
     link_id: Annotated[str | None, Field(description="Link UUID (single mode)")] = None,
     link_ids: Annotated[list[str] | None, Field(description="Batch mode: [\"uuid1\",\"uuid2\"] — get download URLs for multiple captures")] = None,
 ) -> list[dict[str, Any]]:
-    """Get download URL(s) for PCAP capture file(s). The URL includes a short-lived JWT (10 min). Use curl to download."""
+    """Get download command(s) for PCAP capture file(s).
+
+    Returns a ready-to-run curl command per link with a short-lived access
+    ticket (10 min) already embedded in the URL.
+
+    IMPORTANT — copy the returned values EXACTLY:
+      - Run each returned "curl_command" verbatim; it already contains the
+        full URL with ticket. NEVER construct or edit the URL yourself, and
+        NEVER copy the ticket by hand — a mistyped ticket is rejected.
+      - The ticket expires after 10 minutes: call this tool again to get a
+        fresh one; do not reuse an old URL.
+    """
     params = {"project_id": project_id}
     if link_ids:
         params["link_ids"] = link_ids
@@ -1301,7 +1310,13 @@ async def server_statistics() -> list[dict[str, Any]]:
 # async def symbol_get(
 #     symbol_id: Annotated[str, Field(description="Symbol ID (e.g. ':/symbols/router.svg')")],
 # ) -> list[dict[str, Any]]:
-#     """Get a download URL for a symbol file (SVG). The URL includes a short-lived JWT (10 min). Use curl to download."""
+#     """Get a download URL for a symbol file (SVG).
+#
+#     Returns a ready-to-run curl command with a short-lived access ticket
+#     (10 min) embedded in the URL. Run the returned "curl_command" verbatim —
+#     never reconstruct the URL or copy the ticket by hand. Re-call this tool
+#     once the ticket has expired.
+#     """
 #     return await asyncio.to_thread(_run_handler_sync, get_symbol_handler, {
 #         "symbol_id": symbol_id,
 #     })

gns3server/agent/mcp/symbols.py

@@ -23,7 +23,7 @@ from typing import Any
 
 import logging
 
-from gns3server.services import auth_service
+from gns3server.services import access_ticket_service
 
 log = logging.getLogger(__name__)
 
@@ -52,18 +52,25 @@ def get_symbol_handler(params: dict[str, Any], gns3_ctx: dict[str, Any]) -> dict
     symbol_id = params.get("symbol_id")
     if not symbol_id:
         return {"error": "symbol_id is required"}
-    download_url = f"{gns3_ctx['server_url']}/v3/symbols/{symbol_id}/raw"
+    path = f"/v3/symbols/{symbol_id}/raw"
+    download_url = f"{gns3_ctx['server_url']}{path}"
     username = gns3_ctx.get("jwt_username")
-    download_token = auth_service.create_access_token(username, token_version=gns3_ctx.get("jwt_token_version", 0), expires_in=10) if username else None
+    # short-lived ticket bound to this exact path — LLM clients retyping curl
+    # commands corrupted the long Bearer JWT this used to embed
+    ticket = access_ticket_service.mint(
+        username, token_version=gns3_ctx.get("jwt_token_version", 0), path=path
+    ) if username else None
+    if ticket:
+        download_url += f"?token={ticket}"
     result = {
         "symbol_id": symbol_id,
         "download_url": download_url,
         "note": "Symbol files are SVG images.",
     }
-    if download_token:
+    if ticket:
         safe_name = symbol_id.replace(':', '').replace('/', '_')
-        result["curl_command"] = f"curl -L -o '{safe_name}.svg' -H 'Authorization: Bearer {download_token}' '{download_url}'"
-        result["note"] += " Download link includes a 10-minute token."
+        result["curl_command"] = f"curl -L -o '{safe_name}.svg' '{download_url}'"
+        result["note"] += " The download URL includes a 10-minute ticket."
     return result
 
 

gns3server/api/routes/controller/dependencies/authentication.py

@@ -29,7 +29,9 @@ import gns3server.db.models as models
 from gns3server.db.repositories.api_keys import ApiKeysRepository
 from gns3server.db.repositories.users import UsersRepository
 from gns3server.db.repositories.rbac import RbacRepository
-from gns3server.services import auth_service
+from gns3server.schemas.controller.tokens import TokenData
+from gns3server.services import auth_service, access_ticket_service
+from gns3server.services.access_tickets import TICKET_PREFIX
 from .database import get_repository
 
 log = logging.getLogger(__name__)
@@ -48,6 +50,7 @@ def _reject_refresh_token(token_data) -> None:
 
 
 async def get_user_from_token(
+        request: Request,
         bearer_token: str = Depends(oauth2_scheme),
         user_repo: UsersRepository = Depends(get_repository(UsersRepository)),
         api_keys_repo: ApiKeysRepository = Depends(get_repository(ApiKeysRepository)),
@@ -66,6 +69,38 @@ async def get_user_from_token(
             headers={"WWW-Authenticate": "Bearer"},
         )
 
+    if token.startswith(TICKET_PREFIX):
+        # Access tickets ("gns3t_…"): short-lived credentials bound to one
+        # exact resource path, minted by the MCP download tools (capture
+        # files, symbols). redeem_for_path() confines the ticket to that
+        # path, so it cannot be replayed against any other resource.
+        ticket = access_ticket_service.redeem_for_path(token, request.url.path)
+        if ticket is None:
+            raise HTTPException(
+                status_code=status.HTTP_401_UNAUTHORIZED,
+                detail="Invalid or expired access ticket",
+                headers={"WWW-Authenticate": "Bearer"},
+            )
+        token_data = TokenData(
+            username=ticket.username,
+            token_version=ticket.token_version,
+            token_use="access",
+        )
+        user = await user_repo.get_user_by_username(token_data.username)
+        if user is None:
+            raise HTTPException(
+                status_code=status.HTTP_401_UNAUTHORIZED,
+                detail="Could not validate credentials",
+                headers={"WWW-Authenticate": "Bearer"},
+            )
+        if token_data.token_version != user.token_version:
+            raise HTTPException(
+                status_code=status.HTTP_401_UNAUTHORIZED,
+                detail=f"Token has been revoked for '{token_data.username}'",
+                headers={"WWW-Authenticate": "Bearer"},
+            )
+        return user
+
     # API Key authentication — format: gns3_<api_key_id>_<random_secret>
     # Direct lookup by UUID avoids O(n) scan of all keys.
     if token.startswith("gns3_"):
@@ -149,7 +184,25 @@ async def get_current_active_user_from_websocket(
     await websocket.accept(subprotocol=subprotocol)
 
     try:
-        token_data = auth_service.get_token_data(token)
+        if token.startswith(TICKET_PREFIX):
+            # Node-bound access tickets ("gns3t_…"): short-lived credentials
+            # for one node's console endpoints, minted by the node_console
+            # MCP tool. redeem() confines them to the route matching their
+            # binding, so they cannot authenticate the notification/wireshark
+            # sockets that share this dependency.
+            ticket = access_ticket_service.redeem(token, websocket.path_params)
+            if ticket is None:
+                raise HTTPException(
+                    status_code=status.HTTP_401_UNAUTHORIZED,
+                    detail="Invalid or expired console ticket",
+                )
+            token_data = TokenData(
+                username=ticket.username,
+                token_version=ticket.token_version,
+                token_use="access",
+            )
+        else:
+            token_data = auth_service.get_token_data(token)
         _reject_refresh_token(token_data)
         user = await user_repo.get_user_by_username(token_data.username)
 

gns3server/compute/base_node.py

@@ -640,10 +640,20 @@ class BaseNode:
 
         async def telnet_forward(telnet_reader):
 
-            while not telnet_reader.at_eof():
-                data = await telnet_reader.read(1024)
-                if data:
-                    await websocket.send_bytes(data)
+            try:
+                while not telnet_reader.at_eof():
+                    data = await telnet_reader.read(1024)
+                    if data:
+                        await websocket.send_bytes(data)
+            except WebSocketDisconnect:
+                # the client disconnected while node output was still streaming:
+                # normal end of the session, not an error. Starlette raises
+                # WebSocketDisconnect (whose str() is empty) from send once the
+                # peer is gone, which used to surface as a message-less warning.
+                log.info(
+                    f"Client {websocket.client.host}:{websocket.client.port} has disconnected from compute"
+                    f" console WebSocket while node output was being forwarded"
+                )
 
         # keep forwarding websocket data in both direction
         if sys.version_info >= (3, 11, 0):
@@ -657,7 +667,7 @@ class BaseNode:
             if task.exception():
                 log.warning(
                     f"Exception while forwarding WebSocket data to "
-                    f"{self._console_type.upper()} server: {task.exception()}"
+                    f"{self._console_type.upper()} server: {task.exception()!r}"
                 )
         for task in pending:
             task.cancel()
@@ -728,8 +738,16 @@ class BaseNode:
                     data = await vnc_reader.read(65536)  # Larger buffer for VNC frames
                     if data:
                         await websocket.send_bytes(data)
+            except WebSocketDisconnect:
+                # the browser disconnected while VNC frames were still streaming
+                # (starlette raises WebSocketDisconnect with an empty str() from
+                # send once the peer is gone — not an error)
+                log.info(
+                    f"Client {websocket.client.host}:{websocket.client.port} has disconnected from compute "
+                    f"VNC console WebSocket while frames were being forwarded"
+                )
             except Exception as e:
-                log.warning(f"Exception while forwarding VNC data to WebSocket: {e}")
+                log.warning(f"Exception while forwarding VNC data to WebSocket: {e!r}")
 
         # Keep forwarding WebSocket data in both directions
         if sys.version_info >= (3, 11, 0):
@@ -741,7 +759,7 @@ class BaseNode:
         done, pending = await asyncio.wait(aws, return_when=asyncio.FIRST_COMPLETED)
         for task in done:
             if task.exception():
-                log.warning(f"Exception while forwarding WebSocket data to VNC server: {task.exception()}")
+                log.warning(f"Exception while forwarding WebSocket data to VNC server: {task.exception()!r}")
         for task in pending:
             task.cancel()
 

gns3server/services/__init__.py

@@ -15,5 +15,7 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 from .authentication import AuthService
+from .access_tickets import AccessTicketService
 
 auth_service = AuthService()
+access_ticket_service = AccessTicketService()

gns3server/services/access_tickets.py

@@ -0,0 +1,149 @@
+#
+# Copyright (C) 2026 GNS3 Technologies Inc.
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+"""
+Short-lived access tickets.
+
+An access ticket is a short random string ("gns3t_" + 16 urlsafe chars) that
+replaces the long JWTs previously embedded in URLs and curl commands returned
+to LLM clients, which reliably corrupted the ~200-char JWT when retyping it
+into a shell command. The ticket carries no information itself — the server
+remembers what it maps to, which is what makes a 96-bit random string a
+sufficient credential.
+
+A ticket is bound to exactly one target, in one of two modes:
+
+- node binding (project_id + node_id): redeemable on that node's console
+  WebSocket endpoints (console/ws and console/vnc share the binding),
+  validated against the route's path parameters.
+- path binding (exact resource path): redeemable on one REST resource path
+  (e.g. a capture file download or a symbol image), validated against
+  request.url.path.
+
+Tickets are multi-use within their TTL, so clients that reconnect keep
+working. Redemption re-checks the minting user's token_version, so logging
+out invalidates outstanding tickets just like it invalidates JWTs.
+"""
+
+import logging
+import secrets
+import time
+from dataclasses import dataclass
+from typing import Optional
+
+log = logging.getLogger(__name__)
+
+# Distinguishes tickets from JWTs (which contain dots) and API keys ("gns3_")
+TICKET_PREFIX = "gns3t_"
+DEFAULT_TICKET_TTL = 600  # seconds
+
+
+@dataclass
+class AccessTicket:
+    username: str
+    token_version: int
+    project_id: Optional[str] = None  # node binding: console WebSocket endpoints
+    node_id: Optional[str] = None
+    path: Optional[str] = None  # path binding: one exact REST resource path
+    expires_at: float = 0.0  # time.monotonic() based
+
+
+class AccessTicketService:
+    """
+    In-memory store for access tickets.
+
+    Single-process asyncio app: minting (MCP tool handlers, via worker
+    threads) and redemption (auth dependencies, event loop) share one dict.
+    dict get/set/del are atomic under the GIL and keys are random, so no
+    locking is needed. Tickets vanish on restart — clients just request a
+    new one.
+    """
+
+    def __init__(self) -> None:
+        self._tickets: dict[str, AccessTicket] = {}
+
+    def mint(
+        self,
+        username: str,
+        token_version: int,
+        project_id: Optional[str] = None,
+        node_id: Optional[str] = None,
+        path: Optional[str] = None,
+        ttl: int = DEFAULT_TICKET_TTL,
+    ) -> str:
+        # 12 random bytes → 16 urlsafe chars (~96 bits); comfortably
+        # unguessable within the 10-minute window and short enough that
+        # LLM clients copy it without corruption.
+        ticket = TICKET_PREFIX + secrets.token_urlsafe(12)
+        self._sweep_expired()
+        self._tickets[ticket] = AccessTicket(
+            username=username,
+            token_version=token_version,
+            project_id=project_id,
+            node_id=node_id,
+            path=path,
+            expires_at=time.monotonic() + ttl,
+        )
+        return ticket
+
+    def redeem(self, ticket: str, path_params: dict) -> Optional[AccessTicket]:
+        """
+        Validate a node-bound ticket against a WebSocket route.
+
+        Returns the ticket record if valid, None otherwise. The route's path
+        parameters must match the ticket's binding, which confines a ticket
+        to the node's console endpoints — routes without a node_id path
+        parameter (notifications, web wireshark, …) always fail the binding,
+        and so do path-bound (REST) tickets.
+        """
+
+        record = self._get_valid(ticket)
+        if record is None:
+            return None
+        if record.node_id is None or record.path is not None:
+            return None
+        if path_params.get("project_id") != record.project_id or path_params.get("node_id") != record.node_id:
+            return None
+        return record
+
+    def redeem_for_path(self, ticket: str, path: str) -> Optional[AccessTicket]:
+        """
+        Validate a path-bound ticket against a REST resource path.
+
+        The path must match exactly — a ticket minted for one capture file
+        download cannot be replayed against any other resource.
+        """
+
+        record = self._get_valid(ticket)
+        if record is None:
+            return None
+        if record.path is None or record.path != path:
+            return None
+        return record
+
+    def _get_valid(self, ticket: str) -> Optional[AccessTicket]:
+        record = self._tickets.get(ticket)
+        if record is None:
+            return None
+        if time.monotonic() >= record.expires_at:
+            self._tickets.pop(ticket, None)
+            return None
+        return record
+
+    def _sweep_expired(self) -> None:
+        now = time.monotonic()
+        for ticket in [t for t, record in self._tickets.items() if now >= record.expires_at]:
+            del self._tickets[ticket]

tests/agent/mcp/test_handlers.py

@@ -280,10 +280,38 @@ class TestNode:
 
     def test_console(self, ctx):
         from gns3server.agent.gns3_copilot.gns3_client.api_handlers import get_node_console_info_handler
+        from gns3server.services import access_ticket_service
         with patch(f"{AH}._get_connector") as m:
             m.return_value = _mock_conn({"console_url": "ws://host/console"})
             result = get_node_console_info_handler({"project_id": "p1", "node_id": "n1"}, ctx)
             assert "command" in result
+            # the URL embeds a short console ticket (not a JWT) redeemable for this node
+            assert "?token=gns3t_" in result["ws_url"]
+            ticket = result["ws_url"].split("token=")[1]
+            assert ticket in result["command"]
+            assert result["token_ttl_seconds"] == 600
+            assert len(result["token_sha256_prefix"]) == 8
+            redeemed = access_ticket_service.redeem(ticket, {"project_id": "p1", "node_id": "n1"})
+            assert redeemed is not None and redeemed.username == "admin"
+            assert "vnc_url" not in result  # console_type is not vnc
+
+    def test_console_vnc_uses_same_ticket(self, ctx):
+        from gns3server.agent.gns3_copilot.gns3_client.api_handlers import get_node_console_info_handler
+        with patch(f"{AH}._get_connector") as m:
+            m.return_value = _mock_conn({"console_type": "vnc"})
+            result = get_node_console_info_handler({"project_id": "p1", "node_id": "n1"}, ctx)
+            ticket = result["ws_url"].split("token=")[1]
+            # one node-bound ticket covers both console endpoints (identical path params)
+            assert result["vnc_url"] == f"/v3/projects/p1/nodes/n1/console/vnc?token={ticket}"
+
+    def test_console_without_username_omits_token(self, ctx):
+        from gns3server.agent.gns3_copilot.gns3_client.api_handlers import get_node_console_info_handler
+        unauthenticated_ctx = {k: v for k, v in ctx.items() if k != "jwt_username"}
+        with patch(f"{AH}._get_connector") as m:
+            m.return_value = _mock_conn({"console_url": "ws://host/console"})
+            result = get_node_console_info_handler({"project_id": "p1", "node_id": "n1"}, unauthenticated_ctx)
+            assert "token=" not in result["ws_url"]
+            assert "token_sha256_prefix" not in result
 
     @staticmethod
     def _file_conn(text):
@@ -434,6 +462,56 @@ class TestLink:
             }, ctx)
             assert result["suspend"] is True
 
+    def test_download_capture_file(self, ctx):
+        from gns3server.agent.gns3_copilot.gns3_client.api_handlers import download_capture_file_handler
+        from gns3server.services import access_ticket_service
+        result = download_capture_file_handler({"project_id": "p1", "link_id": "l1"}, ctx)
+        # a short path-bound ticket replaces the long Bearer JWT in the URL
+        assert "?token=gns3t_" in result["download_url"]
+        assert "Bearer" not in result["curl_command"]
+        path = f"/v3/projects/p1/links/l1/capture/file"
+        ticket = result["download_url"].split("token=")[1]
+        assert result["curl_command"] == f"curl -L -o capture.pcap '{result['download_url']}'"
+        redeemed = access_ticket_service.redeem_for_path(ticket, path)
+        assert redeemed is not None and redeemed.username == "admin"
+
+    def test_download_capture_file_batch(self, ctx):
+        from gns3server.agent.gns3_copilot.gns3_client.api_handlers import download_capture_file_handler
+        from gns3server.services import access_ticket_service
+        result = download_capture_file_handler({"project_id": "p1", "link_ids": ["l1", "l2"]}, ctx)
+        assert result["count"] == 2
+        # each link gets its own ticket bound to its own download path
+        tickets = [entry["download_url"].split("token=")[1] for entry in result["downloads"]]
+        assert tickets[0] != tickets[1]
+        for lid, ticket in zip(["l1", "l2"], tickets):
+            redeemed = access_ticket_service.redeem_for_path(ticket, f"/v3/projects/p1/links/{lid}/capture/file")
+            assert redeemed is not None
+
+
+# ── Symbol ──────────────────────────────────────────────────────────────
+
+
+class TestSymbol:
+
+    mod = "symbols"
+
+    def test_get_symbol_download(self, ctx):
+        from gns3server.agent.mcp.symbols import get_symbol_handler
+        from gns3server.services import access_ticket_service
+        result = get_symbol_handler({"symbol_id": "router.svg"}, ctx)
+        assert "?token=gns3t_" in result["download_url"]
+        assert "Bearer" not in result["curl_command"]
+        ticket = result["download_url"].split("token=")[1]
+        redeemed = access_ticket_service.redeem_for_path(ticket, "/v3/symbols/router.svg/raw")
+        assert redeemed is not None and redeemed.username == "admin"
+
+    def test_get_symbol_without_username_omits_token(self, ctx):
+        from gns3server.agent.mcp.symbols import get_symbol_handler
+        unauthenticated_ctx = {k: v for k, v in ctx.items() if k != "jwt_username"}
+        result = get_symbol_handler({"symbol_id": "router.svg"}, unauthenticated_ctx)
+        assert "token=" not in result["download_url"]
+        assert "curl_command" not in result
+
 
 # ── Appliance ───────────────────────────────────────────────────────────
 

tests/api/routes/controller/test_access_tickets.py

@@ -0,0 +1,306 @@
+#
+# Copyright (C) 2026 GNS3 Technologies Inc.
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+import hashlib
+from types import SimpleNamespace
+from typing import List
+
+import aiohttp
+import pytest
+from fastapi import FastAPI, status
+from httpx import AsyncClient
+from httpx_ws import aconnect_ws
+from httpx_ws.transport import ASGIWebSocketTransport
+from pydantic import SecretStr
+
+from gns3server.config import Config
+from gns3server.controller import Controller
+from gns3server.controller.compute import Compute
+from gns3server.controller.node import Node
+from gns3server.controller.project import Project
+from gns3server.services import access_ticket_service
+from gns3server.services.access_tickets import (
+    AccessTicketService,
+    DEFAULT_TICKET_TTL,
+    TICKET_PREFIX,
+)
+from gns3server.utils.http_client import HTTPClient
+from tests.api.routes.controller.test_nodes import FakeComputeConsoleWebSocket
+
+
+class TestAccessTicketService:
+    """Unit tests for the in-memory ticket store (fresh instances, no app)."""
+
+    def test_mint_format(self) -> None:
+
+        service = AccessTicketService()
+        ticket = service.mint("admin", 1, project_id="p1", node_id="n1")
+        assert ticket.startswith(TICKET_PREFIX)
+        # 12 random bytes -> 16 urlsafe chars; shell-safe alphabet (no quoting hazards)
+        assert len(ticket) == len(TICKET_PREFIX) + 16
+        assert "." not in ticket  # never confusable with a JWT
+        assert service.mint("admin", 1, project_id="p1", node_id="n1") != ticket
+
+    def test_redeem_valid_ticket_is_multi_use(self) -> None:
+
+        service = AccessTicketService()
+        ticket = service.mint("admin", 7, project_id="p1", node_id="n1")
+        path_params = {"project_id": "p1", "node_id": "n1"}
+        first = service.redeem(ticket, path_params)
+        second = service.redeem(ticket, path_params)  # console clients reconnect, tickets stay usable
+        assert first is not None and second is not None
+        assert first.username == "admin"
+        assert first.token_version == 7
+
+    def test_redeem_rejects_wrong_binding(self) -> None:
+
+        service = AccessTicketService()
+        ticket = service.mint("admin", 0, project_id="p1", node_id="n1")
+        assert service.redeem(ticket, {"project_id": "p1", "node_id": "n2"}) is None
+        assert service.redeem(ticket, {"project_id": "p2", "node_id": "n1"}) is None
+        # routes without a node_id path parameter (notifications, wireshark…) never accept a ticket
+        assert service.redeem(ticket, {"project_id": "p1"}) is None
+        assert service.redeem(ticket, {}) is None
+
+    def test_redeem_rejects_unknown_ticket(self) -> None:
+
+        service = AccessTicketService()
+        assert service.redeem(TICKET_PREFIX + "doesnotexist", {"project_id": "p1", "node_id": "n1"}) is None
+
+    def test_expired_ticket_is_rejected_and_removed(self) -> None:
+
+        service = AccessTicketService()
+        ticket = service.mint("admin", 0, project_id="p1", node_id="n1", ttl=0)
+        assert service.redeem(ticket, {"project_id": "p1", "node_id": "n1"}) is None
+        assert ticket not in service._tickets
+
+    def test_mint_sweeps_expired_entries(self) -> None:
+
+        service = AccessTicketService()
+        stale = service.mint("admin", 0, project_id="p1", node_id="n1", ttl=0)
+        fresh = service.mint("admin", 0, project_id="p1", node_id="n2", ttl=DEFAULT_TICKET_TTL)
+        assert stale not in service._tickets
+        assert fresh in service._tickets
+
+    def test_redeem_for_path_valid_ticket_is_multi_use(self) -> None:
+
+        service = AccessTicketService()
+        ticket = service.mint("admin", 3, path="/v3/projects/p1/links/l1/capture/file")
+        first = service.redeem_for_path(ticket, "/v3/projects/p1/links/l1/capture/file")
+        second = service.redeem_for_path(ticket, "/v3/projects/p1/links/l1/capture/file")
+        assert first is not None and second is not None
+        assert first.username == "admin"
+        assert first.token_version == 3
+
+    def test_redeem_for_path_rejects_other_path(self) -> None:
+
+        service = AccessTicketService()
+        ticket = service.mint("admin", 0, path="/v3/projects/p1/links/l1/capture/file")
+        assert service.redeem_for_path(ticket, "/v3/projects/p1/links/l2/capture/file") is None
+        assert service.redeem_for_path(ticket, "/v3/projects/p2/links/l1/capture/file") is None
+        assert service.redeem_for_path(ticket, "/v3/symbols/router.svg/raw") is None
+
+    def test_binding_modes_are_isolated(self) -> None:
+
+        service = AccessTicketService()
+        # a node-bound ticket must not authenticate REST resources…
+        ws_ticket = service.mint("admin", 0, project_id="p1", node_id="n1")
+        assert service.redeem_for_path(ws_ticket, "/v3/projects/p1/nodes/n1/console/ws") is None
+        # …and a path-bound ticket must not authenticate WebSocket routes
+        rest_ticket = service.mint("admin", 0, path="/v3/projects/p1/links/l1/capture/file")
+        assert service.redeem(rest_ticket, {"project_id": "p1", "node_id": "n1"}) is None
+
+
+class TestAccessTicketWebSocketAuth:
+    """
+    Drive the console WebSocket auth dependency end-to-end through the real
+    routes (the shared service singleton is the one the dependency consults).
+    """
+
+    pytestmark = pytest.mark.asyncio
+
+    @pytest.fixture(autouse=True)
+    def _reset_controller_singleton(self, controller):
+        # The project/compute fixtures register state on the shared Controller
+        # singleton; reset it after each test so files running later (e.g. the
+        # controller statistics endpoint) see a pristine controller regardless
+        # of test order — same reset the controller fixture applies at setup.
+        yield
+        Controller._instance = None
+
+    @pytest.fixture
+    def node(self, project: Project, compute: Compute) -> Node:
+
+        compute.host = "127.0.0.1"
+        compute.port = 3080
+        node = Node(project, compute, "test", node_type="vpcs")
+        project._nodes[node.id] = node
+        return node
+
+    @pytest.fixture
+    def compute_credentials(self) -> None:
+
+        server_config = Config.instance().settings.Server
+        server_config.compute_username = "admin"
+        server_config.compute_password = SecretStr("password")
+
+    @staticmethod
+    def _ws_client(app: FastAPI, base_client: AsyncClient) -> AsyncClient:
+        # base_client must be requested so the app gets the test-DB dependency
+        # override, but the WebSocket connection itself needs a function-local
+        # client: closing the WS transport from the class-scoped base_client
+        # teardown exits anyio cancel scopes in the wrong task.
+        return AsyncClient(base_url="http://test-api", transport=ASGIWebSocketTransport(app=app))
+
+    @staticmethod
+    def _forward_compute_ws(monkeypatch, messages: List[aiohttp.WSMessage]) -> FakeComputeConsoleWebSocket:
+
+        compute_ws = FakeComputeConsoleWebSocket(messages)
+        monkeypatch.setattr(
+            HTTPClient,
+            "get_client",
+            classmethod(lambda cls: SimpleNamespace(ws_connect=lambda *args, **kwargs: compute_ws))
+        )
+        return compute_ws
+
+    async def test_console_ws_accepts_valid_ticket(
+            self,
+            app: FastAPI,
+            base_client: AsyncClient,
+            compute_credentials,
+            project: Project,
+            node: Node,
+            monkeypatch
+    ) -> None:
+        # admin is the seeded superadmin, so the RBAC privilege check is skipped
+        ticket = access_ticket_service.mint("admin", 0, project_id=project.id, node_id=node.id)
+        self._forward_compute_ws(monkeypatch, [
+            aiohttp.WSMessage(aiohttp.WSMsgType.TEXT, "device output", None),
+        ])
+
+        async with self._ws_client(app, base_client) as client:
+            async with aconnect_ws(
+                    f"/v3/projects/{project.id}/nodes/{node.id}/console/ws",
+                    client,
+                    params={"token": ticket}
+            ) as ws:
+                # reaching the compute forwarding loop means ticket auth succeeded
+                assert await ws.receive_text() == "device output"
+
+    async def test_console_ws_rejects_ticket_bound_to_other_node(
+            self,
+            app: FastAPI,
+            base_client: AsyncClient,
+            project: Project,
+            node: Node
+    ) -> None:
+
+        other_node = "00000000-0000-0000-0000-000000000000"
+        ticket = access_ticket_service.mint("admin", 0, project_id=project.id, node_id=other_node)
+        async with self._ws_client(app, base_client) as client:
+            async with aconnect_ws(
+                    f"/v3/projects/{project.id}/nodes/{node.id}/console/ws",
+                    client,
+                    params={"token": ticket}
+            ) as ws:
+                notification = await ws.receive_json()
+                assert notification["event"]["message"] == (
+                    "Could not authenticate while connecting to controller WebSocket: "
+                    "Invalid or expired console ticket "
+                    f"(received token sha256 prefix: {hashlib.sha256(ticket.encode()).hexdigest()[:8]})"
+                )
+
+    async def test_console_ws_rejects_ticket_with_stale_token_version(
+            self,
+            app: FastAPI,
+            base_client: AsyncClient,
+            project: Project,
+            node: Node
+    ) -> None:
+        # logging out bumps the user's token_version: outstanding tickets must die with it
+        ticket = access_ticket_service.mint("admin", 999, project_id=project.id, node_id=node.id)
+        async with self._ws_client(app, base_client) as client:
+            async with aconnect_ws(
+                    f"/v3/projects/{project.id}/nodes/{node.id}/console/ws",
+                    client,
+                    params={"token": ticket}
+            ) as ws:
+                notification = await ws.receive_json()
+                assert "Token has been revoked for 'admin'" in notification["event"]["message"]
+
+    async def test_ticket_rejected_on_non_console_websocket(
+            self,
+            app: FastAPI,
+            base_client: AsyncClient
+    ) -> None:
+        # the controller notification stream shares the WS auth dependency but has
+        # no node binding: a console ticket must not authenticate it
+        ticket = access_ticket_service.mint("admin", 0, project_id="p1", node_id="n1")
+        async with self._ws_client(app, base_client) as client:
+            async with aconnect_ws("/v3/notifications/ws", client, params={"token": ticket}) as ws:
+                notification = await ws.receive_json()
+                assert "Invalid or expired console ticket" in notification["event"]["message"]
+
+
+class TestAccessTicketRestAuth:
+    """
+    Drive the REST auth dependency (get_user_from_token) end-to-end: a
+    path-bound ticket authenticates exactly one resource path.
+    """
+
+    pytestmark = pytest.mark.asyncio
+
+    async def test_rest_accepts_path_bound_ticket(
+            self,
+            app: FastAPI,
+            base_client: AsyncClient
+    ) -> None:
+        # base_client carries no Authorization header, so the ?token= parameter is used
+        ticket = access_ticket_service.mint("admin", 0, path="/v3/projects")
+        response = await base_client.get("/v3/projects", params={"token": ticket})
+        assert response.status_code == status.HTTP_200_OK
+
+    async def test_rest_rejects_ticket_bound_to_other_path(
+            self,
+            app: FastAPI,
+            base_client: AsyncClient
+    ) -> None:
+
+        ticket = access_ticket_service.mint("admin", 0, path="/v3/symbols/router.svg/raw")
+        response = await base_client.get("/v3/projects", params={"token": ticket})
+        assert response.status_code == status.HTTP_401_UNAUTHORIZED
+        assert "Invalid or expired access ticket" in response.text
+
+    async def test_rest_rejects_node_bound_ticket(
+            self,
+            app: FastAPI,
+            base_client: AsyncClient
+    ) -> None:
+        # node-bound (console) tickets must not authenticate REST resources
+        ticket = access_ticket_service.mint("admin", 0, project_id="p1", node_id="n1")
+        response = await base_client.get("/v3/projects", params={"token": ticket})
+        assert response.status_code == status.HTTP_401_UNAUTHORIZED
+
+    async def test_rest_rejects_ticket_with_stale_token_version(
+            self,
+            app: FastAPI,
+            base_client: AsyncClient
+    ) -> None:
+        # logging out bumps the user's token_version: outstanding tickets must die with it
+        ticket = access_ticket_service.mint("admin", 999, path="/v3/projects")
+        response = await base_client.get("/v3/projects", params={"token": ticket})
+        assert response.status_code == status.HTTP_401_UNAUTHORIZED
+        assert "revoked" in response.text

tests/compute/test_base_node.py

@@ -453,3 +453,57 @@ async def test_stop_ubridge_clears_marker_bridges(compute_project, manager):
     node._marker_filter_bridges["m", "L1"] = "VPCS-10"
     await node._stop_ubridge()
     assert node._marker_filter_bridges == {}
+
+
+class _GoneConsoleWebsocket:
+    """
+    Stand-in for the compute-side WebSocket when the peer (the controller, or a
+    browser) is already gone: receive() yields the disconnect message and
+    send_bytes raises WebSocketDisconnect — what starlette raises from send
+    after the transport reports OSError.
+    """
+
+    def __init__(self):
+        from types import SimpleNamespace
+        self.client = SimpleNamespace(host="127.0.0.1", port=5000)
+
+    async def receive(self):
+        return {"type": "websocket.disconnect"}
+
+    async def send_bytes(self, data):
+        from starlette.websockets import WebSocketDisconnect
+        raise WebSocketDisconnect(code=1006)
+
+
+@pytest.mark.asyncio
+async def test_console_websocket_client_disconnect_while_node_output_streams(
+        compute_project, manager, port_manager, monkeypatch, caplog):
+    # regression test: the client disconnects while the node is still streaming
+    # console output. telnet_forward used to let the (empty-str) WebSocketDisconnect
+    # from send_bytes escape, logging a message-less WARNING.
+    import asyncio
+    import logging
+
+    node = VPCSVM("test", "00010203-0405-0607-0809-0a0b0c0d0e0f", compute_project, manager)
+    node.status = "started"
+
+    telnet_reader = MagicMock()
+    telnet_reader.at_eof.return_value = False
+    telnet_reader.read = AsyncioMagicMock(return_value=b"device output")
+    telnet_writer = MagicMock()
+    telnet_writer.wait_closed = AsyncioMagicMock()
+
+    async def fake_open_connection(*args, **kwargs):
+        return telnet_reader, telnet_writer
+
+    monkeypatch.setattr(asyncio, "open_connection", fake_open_connection)
+
+    with caplog.at_level(logging.INFO):
+        await node.start_websocket_console(_GoneConsoleWebsocket())
+
+    assert telnet_writer.close.called
+    assert not [r for r in caplog.records if r.levelno >= logging.WARNING]
+    assert any(
+        "has disconnected from compute console WebSocket while node output" in r.message
+        for r in caplog.records
+    )