| | | 1 | | using AsyncResponse; |
| | | 2 | | |
| | | 3 | | namespace Microsoft.Extensions.DependencyInjection; |
| | | 4 | | |
| | | 5 | | /// <summary> |
| | | 6 | | /// Builds an allowlist of callback targets for <see cref="IAsyncResponseCallbackAuthorizer"/>. |
| | | 7 | | /// Configure it once, at the type level — no per-method attributes. A target is allowed when its |
| | | 8 | | /// service type is allowed, or when any registered predicate accepts the <c>(type, method)</c> pair. |
| | | 9 | | /// </summary> |
| | | 10 | | public sealed class AsyncResponseCallbackAllowList |
| | | 11 | | { |
| | | 12 | | private readonly HashSet<string> _allowedTypes = new(StringComparer.Ordinal); |
| | | 13 | | private readonly List<Func<string, string, bool>> _predicates = []; |
| | | 14 | | |
| | | 15 | | /// <summary> |
| | | 16 | | /// Whether the built-in <see cref="IDurableFlowExecutor"/> is allowed as a callback target. |
| | | 17 | | /// Defaults to <c>true</c>: durable flows persist its methods as their resume/recover/fail |
| | | 18 | | /// targets, and rejecting them would break flow recovery. Note the security trade-off — an |
| | | 19 | | /// attacker with write access to the recovery store or worker transport can then invoke |
| | | 20 | | /// flow-executor methods (bounded to flow ids, terminal failure, and checkpointing a payload |
| | | 21 | | /// into a flow's ledger; see docs/security.md). Hosts that do not use durable flows, or that |
| | | 22 | | /// accept re-registering the executor themselves, can set this to <c>false</c>. |
| | | 23 | | /// </summary> |
| | | 24 | | public bool AllowDurableFlowExecutor { get; set; } = true; |
| | | 25 | | |
| | | 26 | | /// <summary>Allows every callback method on the given service type.</summary> |
| | | 27 | | public AsyncResponseCallbackAllowList Allow(Type serviceType) |
| | | 28 | | { |
| | | 29 | | ArgumentNullException.ThrowIfNull(serviceType); |
| | | 30 | | if (serviceType.FullName is { } name) |
| | | 31 | | _allowedTypes.Add(name); |
| | | 32 | | return this; |
| | | 33 | | } |
| | | 34 | | |
| | | 35 | | /// <summary>Allows every callback method on the given service type.</summary> |
| | | 36 | | public AsyncResponseCallbackAllowList Allow<TService>() => Allow(typeof(TService)); |
| | | 37 | | |
| | | 38 | | /// <summary>Allows a callback by its persisted service full name (for types not referenceable at config time).</sum |
| | | 39 | | public AsyncResponseCallbackAllowList Allow(string serviceInterfaceFullName) |
| | | 40 | | { |
| | | 41 | | ArgumentException.ThrowIfNullOrWhiteSpace(serviceInterfaceFullName); |
| | | 42 | | _allowedTypes.Add(serviceInterfaceFullName); |
| | | 43 | | return this; |
| | | 44 | | } |
| | | 45 | | |
| | | 46 | | /// <summary>Allows callbacks matching a custom predicate over the <c>(serviceFullName, methodName)</c> pair.</summa |
| | | 47 | | public AsyncResponseCallbackAllowList Allow(Func<string, string, bool> predicate) |
| | | 48 | | { |
| | | 49 | | ArgumentNullException.ThrowIfNull(predicate); |
| | | 50 | | _predicates.Add(predicate); |
| | | 51 | | return this; |
| | | 52 | | } |
| | | 53 | | |
| | | 54 | | internal IAsyncResponseCallbackAuthorizer Build() |
| | | 55 | | { |
| | | 56 | | // Materialized at build time (not special-cased in IsAllowed) so the executor shows up in |
| | | 57 | | // the same allowlist mechanism as every other target and stays overridable by config. |
| | | 58 | | if (AllowDurableFlowExecutor && typeof(IDurableFlowExecutor).FullName is { } executorName) |
| | | 59 | | _allowedTypes.Add(executorName); |
| | | 60 | | |
| | | 61 | | return new AllowListAuthorizer(_allowedTypes, _predicates); |
| | | 62 | | } |
| | | 63 | | |
| | 2 | 64 | | private sealed class AllowListAuthorizer(HashSet<string> allowedTypes, List<Func<string, string, bool>> predicates) |
| | | 65 | | : IAsyncResponseCallbackAuthorizer |
| | | 66 | | { |
| | | 67 | | /// <summary>Runs the IsAllowed operation.</summary> |
| | | 68 | | public bool IsAllowed(string serviceInterfaceFullName, string methodName) |
| | | 69 | | { |
| | 2 | 70 | | if (allowedTypes.Contains(serviceInterfaceFullName)) |
| | 2 | 71 | | return true; |
| | | 72 | | |
| | 2 | 73 | | foreach (var predicate in predicates) |
| | | 74 | | { |
| | 2 | 75 | | if (predicate(serviceInterfaceFullName, methodName)) |
| | 2 | 76 | | return true; |
| | | 77 | | } |
| | | 78 | | |
| | 2 | 79 | | return false; |
| | 2 | 80 | | } |
| | | 81 | | } |
| | | 82 | | } |
| | | 83 | | |
| | | 84 | | /// <summary> |
| | | 85 | | /// Opt-in registration for callback authorization (review item 1). By default no authorizer is |
| | | 86 | | /// registered and any DI-registered service method may be a callback target — calling these methods |
| | | 87 | | /// is the only thing that turns on the allowlist. |
| | | 88 | | /// </summary> |
| | | 89 | | public static class AsyncResponseCallbackAuthorizationExtensions |
| | | 90 | | { |
| | | 91 | | /// <summary>Registers an allowlist authorizer configured by <paramref name="configure"/>.</summary> |
| | | 92 | | public static AsyncResponseRegistrationBuilder AuthorizeCallbacks( |
| | | 93 | | this AsyncResponseRegistrationBuilder builder, |
| | | 94 | | Action<AsyncResponseCallbackAllowList> configure) |
| | | 95 | | { |
| | | 96 | | ArgumentNullException.ThrowIfNull(builder); |
| | | 97 | | ArgumentNullException.ThrowIfNull(configure); |
| | | 98 | | |
| | | 99 | | var allowList = new AsyncResponseCallbackAllowList(); |
| | | 100 | | configure(allowList); |
| | | 101 | | builder.Services.AddSingleton(allowList.Build()); |
| | | 102 | | return builder; |
| | | 103 | | } |
| | | 104 | | |
| | | 105 | | /// <summary> |
| | | 106 | | /// Registers a custom <see cref="IAsyncResponseCallbackAuthorizer"/>. Unlike the allowlist |
| | | 107 | | /// overload, nothing is allowed implicitly: when durable flows are enabled the authorizer must |
| | | 108 | | /// allow <see cref="IDurableFlowExecutor"/>, whose methods are persisted as every flow's |
| | | 109 | | /// resume/recover/fail targets — rejecting them breaks flow recovery. |
| | | 110 | | /// </summary> |
| | | 111 | | public static AsyncResponseRegistrationBuilder AuthorizeCallbacks( |
| | | 112 | | this AsyncResponseRegistrationBuilder builder, |
| | | 113 | | IAsyncResponseCallbackAuthorizer authorizer) |
| | | 114 | | { |
| | | 115 | | ArgumentNullException.ThrowIfNull(builder); |
| | | 116 | | ArgumentNullException.ThrowIfNull(authorizer); |
| | | 117 | | builder.Services.AddSingleton(authorizer); |
| | | 118 | | return builder; |
| | | 119 | | } |
| | | 120 | | } |