58 lines
No EOL
2.3 KiB
C#
58 lines
No EOL
2.3 KiB
C#
using System.Net;
|
|
using Iceshrimp.Backend.Core.Configuration;
|
|
using Iceshrimp.Backend.Core.Database;
|
|
using Iceshrimp.Backend.Core.Federation.ActivityPub;
|
|
using Iceshrimp.Backend.Core.Federation.Cryptography;
|
|
using Microsoft.AspNetCore.Http.Features;
|
|
using Microsoft.EntityFrameworkCore;
|
|
using Microsoft.Extensions.Options;
|
|
|
|
namespace Iceshrimp.Backend.Core.Middleware;
|
|
|
|
public class AuthorizedFetchMiddleware(
|
|
IOptionsSnapshot<Config.SecuritySection> config,
|
|
DatabaseContext db,
|
|
UserResolver userResolver,
|
|
ILogger<AuthorizedFetchMiddleware> logger) : IMiddleware {
|
|
public async Task InvokeAsync(HttpContext ctx, RequestDelegate next) {
|
|
var endpoint = ctx.Features.Get<IEndpointFeature>()?.Endpoint;
|
|
var attribute = endpoint?.Metadata.GetMetadata<AuthorizedFetchAttribute>();
|
|
|
|
if (attribute != null && config.Value.AuthorizedFetch) {
|
|
var request = ctx.Request;
|
|
if (!request.Headers.TryGetValue("signature", out var sigHeader))
|
|
throw new CustomException(HttpStatusCode.Unauthorized, "Request is missing the signature header");
|
|
|
|
var sig = HttpSignature.Parse(sigHeader.ToString());
|
|
|
|
// First, we check if we already have the key
|
|
var key = await db.UserPublickeys.FirstOrDefaultAsync(p => p.KeyId == sig.KeyId);
|
|
|
|
// If we don't, we need to try to fetch it
|
|
if (key == null) {
|
|
var user = await userResolver.Resolve(sig.KeyId);
|
|
key = await db.UserPublickeys.FirstOrDefaultAsync(p => p.UserId == user.Id);
|
|
}
|
|
|
|
// If we still don't have the key, something went wrong and we need to throw an exception
|
|
if (key == null) throw new CustomException("Failed to fetch key of signature user");
|
|
|
|
//TODO: re-fetch key once if signature validation fails, to properly support key rotation
|
|
|
|
List<string> headers = request.Body.Length > 0 || attribute.ForceBody
|
|
? ["(request-target)", "digest", "host", "date"]
|
|
: ["(request-target)", "host", "date"];
|
|
|
|
var verified = await HttpSignature.Verify(ctx.Request, sig, headers, key.KeyPem);
|
|
logger.LogDebug("HttpSignature.Verify returned {result} for key {keyId}", verified, sig.KeyId);
|
|
if (!verified)
|
|
throw new CustomException(HttpStatusCode.Forbidden, "Request signature validation failed");
|
|
}
|
|
|
|
await next(ctx);
|
|
}
|
|
}
|
|
|
|
public class AuthorizedFetchAttribute(bool forceBody = false) : Attribute {
|
|
public bool ForceBody { get; } = forceBody;
|
|
} |