fix: replace Bearer JWTs with path-bound access tickets in MCP download tools

link_capture_download and get_symbol embedded a 10-min JWT in the
Authorization header of the curl command they return; LLM clients
retyping that command corrupted the long token — the same failure
class as the console WebSocket URLs fixed in the previous commit.

Generalize the ticket store (console_tickets.py -> access_tickets.py,
ConsoleTicketService -> AccessTicketService): a ticket now binds to
either a node's console endpoints (WebSocket, matched against route
path params) or one exact REST resource path (capture file, symbol
image). The two binding modes are isolated — a node-bound ticket
cannot authenticate a REST resource and vice versa.

get_user_from_token redeems path-bound tickets through the existing
token parameter / Bearer header, matched exactly against
request.url.path, then reuses the shared user lookup and token_version
revocation checks. Download URLs embed ?token=<ticket> and the curl
commands no longer carry a Bearer header.

gns3server/agent/gns3_copilot/gns3_client/api_handlers.py

@@ -53,8 +53,8 @@ from concurrent.futures import ThreadPoolExecutor
 import hashlib
 import logging
 
-from gns3server.services import auth_service, console_ticket_service
-from gns3server.services.console_tickets import DEFAULT_TICKET_TTL
+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
 
@@ -423,7 +423,7 @@ def get_node_console_info_handler(params: dict[str, Any], gns3_ctx: dict[str, An
     # the ~200-char JWT previously embedded here (dropped header segment →
     # "Missing 'alg' value in header" on the server).
     username = gns3_ctx.get("jwt_username")
-    ticket = console_ticket_service.mint(
+    ticket = access_ticket_service.mint(
         username,
         token_version=gns3_ctx.get("jwt_token_version", 0),
         project_id=project_id,
@@ -859,34 +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/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

@@ -30,8 +30,8 @@ from gns3server.db.repositories.api_keys import ApiKeysRepository
 from gns3server.db.repositories.users import UsersRepository
 from gns3server.db.repositories.rbac import RbacRepository
 from gns3server.schemas.controller.tokens import TokenData
-from gns3server.services import auth_service, console_ticket_service
-from gns3server.services.console_tickets import TICKET_PREFIX
+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__)
@@ -50,6 +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)),
@@ -68,6 +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_"):
@@ -152,12 +185,12 @@ async def get_current_active_user_from_websocket(
 
     try:
         if token.startswith(TICKET_PREFIX):
-            # Console tickets ("gns3t_…"): short-lived credentials bound to 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 = console_ticket_service.redeem(token, websocket.path_params)
+            # 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,

gns3server/services/__init__.py

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

gns3server/services/access_tickets.py

@@ -15,20 +15,27 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 """
-Short-lived console tickets.
+Short-lived access tickets.
 
-A console ticket is a short random string ("gns3t_" + 16 urlsafe chars) that
-replaces the long JWT previously embedded in console WebSocket URLs returned
+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.
 
-Tickets are bound to a single node's console endpoints (console/ws and
-console/vnc share the same binding) and are multi-use within their TTL, so
-console clients that reconnect after a drop keep working. Redeeming also
-re-checks the minting user's token_version, so logging out invalidates
-outstanding tickets just like it invalidates JWTs.
+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
@@ -45,34 +52,36 @@ DEFAULT_TICKET_TTL = 600  # seconds
 
 
 @dataclass
-class ConsoleTicket:
+class AccessTicket:
     username: str
     token_version: int
-    project_id: str
-    node_id: str
-    expires_at: float  # time.monotonic() based
+    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 ConsoleTicketService:
+class AccessTicketService:
     """
-    In-memory store for console tickets.
+    In-memory store for access tickets.
 
     Single-process asyncio app: minting (MCP tool handlers, via worker
-    threads) and redemption (WS auth dependency, event loop) share one dict.
+    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, ConsoleTicket] = {}
+        self._tickets: dict[str, AccessTicket] = {}
 
     def mint(
         self,
         username: str,
         token_version: int,
-        project_id: str,
-        node_id: str,
+        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
@@ -80,33 +89,58 @@ class ConsoleTicketService:
         # LLM clients copy it without corruption.
         ticket = TICKET_PREFIX + secrets.token_urlsafe(12)
         self._sweep_expired()
-        self._tickets[ticket] = ConsoleTicket(
+        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[ConsoleTicket]:
+    def redeem(self, ticket: str, path_params: dict) -> Optional[AccessTicket]:
         """
-        Validate a ticket against the route it is being used on.
+        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.
+        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
-        if path_params.get("project_id") != record.project_id or path_params.get("node_id") != record.node_id:
-            return None
         return record
 
     def _sweep_expired(self) -> None: