Files
Musify/backend/Musify.StreamingGateway/Middleware/TicketValidationMiddleware.cs
T
AdminandClaude Opus 4.8 45ce66a6ee harden(gateway): prefix-boundary + path-traversal checks; simplify ticket validation
Tighten the stream-ticket authorization in the gateway middleware:
- Enforce a path-segment boundary on the prefix check instead of a bare
  StartsWith, so a ticket for 'users/12' no longer grants 'users/1234/...'
  (exact-match still allowed for single-object grants)
- Reject object keys containing '..'/'.' segments before proxying, closing a
  path-traversal bypass that SeaweedFS would otherwise resolve outside the
  authorized prefix

Also simplify TicketValidator.ValidateTicketAsync from ErrorOr<string> to
string? (null = invalid) since it has a single failure mode; drop the now
unused ErrorOr package reference from the gateway.

Verified: build clean; the authorization predicate passes a table of cases
covering both the escalation and traversal vulnerabilities.

Build: 0 warnings, 0 errors.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
2026-07-05 21:50:43 +02:00

75 lines
2.7 KiB
C#

using Microsoft.Extensions.Options;
using Musify.StreamingGateway.Authentication;
using Musify.StreamingGateway.Configuration;
namespace Musify.StreamingGateway.Middleware;
public sealed class TicketValidationMiddleware(
RequestDelegate next,
TicketValidator ticketValidator,
IOptions<StreamTicketValidationOptions> options,
ILogger<TicketValidationMiddleware> logger)
{
private readonly StreamTicketValidationOptions options = options.Value;
public async Task InvokeAsync(HttpContext context)
{
var path = context.Request.Path;
if (!path.StartsWithSegments(options.MediaPathPrefix, out var remaining))
{
await next(context);
return;
}
var token = context.Request.Query[options.QueryParameterName].ToString();
if (string.IsNullOrEmpty(token))
{
token = context.Request.Headers[options.HeaderName].ToString();
}
var prefix = await ticketValidator.ValidateTicketAsync(token);
if (prefix is null)
{
logger.LogWarning("Rejected media request {Path}: missing or invalid ticket", path);
context.Response.StatusCode = StatusCodes.Status401Unauthorized;
return;
}
var objectKey = remaining.Value?.TrimStart('/') ?? string.Empty;
if (HasTraversalSegment(objectKey))
{
logger.LogWarning("Rejected media request {ObjectKey}: contains a path traversal segment", objectKey);
context.Response.StatusCode = StatusCodes.Status400BadRequest;
return;
}
var prefixBoundary = prefix.EndsWith('/') ? prefix : prefix + "/";
if (!string.Equals(objectKey, prefix, StringComparison.Ordinal)
&& !objectKey.StartsWith(prefixBoundary, StringComparison.Ordinal))
{
logger.LogWarning("Rejected media request {ObjectKey}: outside authorized prefix {Prefix}", objectKey, prefix);
context.Response.StatusCode = StatusCodes.Status403Forbidden;
return;
}
StripQueryParameter(context, options.QueryParameterName);
await next(context);
}
private static bool HasTraversalSegment(string objectKey) =>
objectKey.Split('/').Any(segment => segment is ".." or ".");
private static void StripQueryParameter(HttpContext context, string name)
{
var remaining = context.Request.Query
.Where(pair => !string.Equals(pair.Key, name, StringComparison.Ordinal))
.SelectMany(pair => pair.Value.Select(value => new KeyValuePair<string, string?>(pair.Key, value)))
.ToList();
context.Request.QueryString = QueryString.Create(remaining);
}
}