feat: sign in with a passkey (WebAuthn, ES256, discoverable credentials) and manage your passkeys [CI]

backend/src/MoShiro.Backend.Api/Admin/AuthEndpoints.cs

@@ -19,6 +19,14 @@ public static class AuthEndpoints
             .AllowsAnonymous()
             .Api("auth_login", "Sign in with a username and password", Tag)
             .Returns<LoginResponse>().ProducesProblems(400, 401, 429);
+        open.MapPost("/auth/passkey/options", PasskeyLoginOptions)
+            .AllowsAnonymous()
+            .Api("auth_passkey_options", "A challenge for signing in with a passkey (discoverable credential, no username needed)", Tag)
+            .Returns<PasskeyRequestOptionsDto>().ProducesProblems(429);
+        open.MapPost("/auth/passkey/login", PasskeyLoginAsync)
+            .AllowsAnonymous()
+            .Api("auth_passkey_login", "Sign in with a passkey assertion; same response as the password sign-in", Tag)
+            .Returns<LoginResponse>().ProducesProblems(400, 401, 429);
     }
 
     public static void MapSession(RouteGroupBuilder guarded)
@@ -27,6 +35,22 @@ public static class AuthEndpoints
             .Api("auth_logout", "Sign out and clear the session cookie", Tag)
             .Returns<object>(StatusCodes.Status204NoContent).ProducesProblems(401)
             .Requires(Capability.Authenticated);
+        guarded.MapGet("/auth/passkeys", ListPasskeysAsync)
+            .Api("auth_passkeys_list", "The signed-in user's passkeys", Tag)
+            .Returns<PageDto<PasskeyDto>>().ProducesProblems(401)
+            .Requires(Capability.Authenticated);
+        guarded.MapPost("/auth/passkeys/options", PasskeyCreationOptionsAsync)
+            .Api("auth_passkeys_options", "A challenge for registering a new passkey (the user must be signed in)", Tag)
+            .Returns<PasskeyCreationOptionsDto>().ProducesProblems(400, 401, 403)
+            .Requires(Capability.Authenticated);
+        guarded.MapPost("/auth/passkeys", RegisterPasskeyAsync)
+            .Api("auth_passkeys_register", "Register a passkey from a WebAuthn attestation (ES256, user verification required)", Tag)
+            .Returns<PasskeyDto>(StatusCodes.Status201Created).ProducesProblems(400, 401, 403, 409)
+            .Requires(Capability.Authenticated);
+        guarded.MapDelete("/auth/passkeys/{id}", DeletePasskeyAsync)
+            .Api("auth_passkeys_delete", "Remove one of your own passkeys", Tag)
+            .Returns<object>(StatusCodes.Status204NoContent).ProducesProblems(401, 404)
+            .Requires(Capability.Authenticated);
         guarded.MapGet("/auth/me", Me)
             .Api("auth_me", "The current identity", Tag)
             .Returns<MeDto>().ProducesProblems(401)
@@ -47,8 +71,12 @@ public static class AuthEndpoints
             return Problems.From(http, error);
         }
 
-        // 跨域的前端（return_session）不用 Cookie：会话令牌放在响应里，之后用 Bearer 带上
-        bool returnSession = request.ReturnSession == true;
+        return IssueSession(http, login, request.ReturnSession == true, options);
+    }
+
+    /// <summary>发放会话：Cookie（同源前端）或在响应里返回会话令牌（跨域前端的 return_session）。密码登录和 passkey 登录共用。</summary>
+    private static Microsoft.AspNetCore.Http.HttpResults.JsonHttpResult<LoginResponse> IssueSession(HttpContext http, LoginResult login, bool returnSession, BackendOptions options)
+    {
         if (!returnSession)
         {
             http.Response.Cookies.Append(
@@ -68,6 +96,88 @@ public static class AuthEndpoints
         return TypedResults.Json(new LoginResponse(login.UserId, login.Username, login.CsrfToken, Mappers.Time(login.ExpiresAtMs), returnSession ? login.SessionToken : null), ApiJsonContext.Default.LoginResponse);
     }
 
+    /// <summary>这次请求的 WebAuthn 依赖方：配置优先，其次面板对外地址，最后是请求自己的主机。</summary>
+    private static PasskeyContext PasskeyContextOf(HttpContext http, BackendOptions options)
+    {
+        string own = $"{http.Request.Scheme}://{http.Request.Host}";
+        Uri? configured = Uri.TryCreate(options.PublicUrl, UriKind.Absolute, out Uri? uri) ? uri : null;
+        string rpId = !string.IsNullOrWhiteSpace(options.WebAuthnRpId) ? options.WebAuthnRpId.Trim() : configured?.Host ?? http.Request.Host.Host;
+        IEnumerable<string> origins = !string.IsNullOrWhiteSpace(options.WebAuthnOrigins)
+            ? options.WebAuthnOrigins.Split(',', StringSplitOptions.RemoveEmptyEntries | StringSplitOptions.TrimEntries).Select(o => o.TrimEnd('/'))
+            : [configured is null ? own : configured.GetLeftPart(UriPartial.Authority)];
+        return new PasskeyContext(rpId, new HashSet<string>(origins, StringComparer.Ordinal));
+    }
+
+    /// <summary>限流。<paramref name="scope"/> 把「取挑战」和「提交登录」分成两个桶：页面加载取挑战不该占用登录失败的额度。</summary>
+    private static IResult Limited(HttpContext http, LoginRateLimiter limiter, out bool ok, string scope = "", int? limit = null)
+    {
+        string source = scope + (http.Connection.RemoteIpAddress?.ToString() ?? "unknown");
+        ok = limiter.TryAcquire(source, out int retryAfter, limit);
+        return ok ? TypedResults.NoContent() : Problems.RetryAfter(http, new FleetError(MoShiroErrors.TooManyRequests, "too many sign-in attempts"), retryAfter);
+    }
+
+    /// <summary>取挑战只是页面加载和点按钮，不是猜密码：额度比登录失败宽松，挑战总量另有上限（淘汰最旧的）。</summary>
+    private const int PasskeyOptionsPerMinute = 60;
+
+    private static IResult PasskeyLoginOptions(HttpContext http, PasskeyService passkeys, LoginRateLimiter limiter, BackendOptions options)
+    {
+        IResult limit = Limited(http, limiter, out bool ok, "passkey-options:", limit: PasskeyOptionsPerMinute);
+        if (!ok)
+        {
+            return limit;
+        }
+
+        RequestOptions o = passkeys.BeginLogin(PasskeyContextOf(http, options));
+        http.Response.Headers.CacheControl = "no-store";
+        return TypedResults.Json(new PasskeyRequestOptionsDto(o.Challenge, o.RpId, o.TimeoutMs), ApiJsonContext.Default.PasskeyRequestOptionsDto);
+    }
+
+    private static async Task<IResult> PasskeyLoginAsync(HttpContext http, PasskeyLoginRequest request, PasskeyService passkeys, LoginRateLimiter limiter, BackendOptions options)
+    {
+        IResult limit = Limited(http, limiter, out bool ok);
+        if (!ok)
+        {
+            return limit;
+        }
+
+        Result<LoginResult> result = await passkeys.LoginAsync(
+            new PasskeyAssertion(request.CredentialId ?? "", request.AuthenticatorData ?? "", request.ClientDataJson ?? "", request.Signature ?? ""), PasskeyContextOf(http, options), http.RequestAborted);
+        return result.TryGet(out LoginResult? login, out FleetError? error) ? IssueSession(http, login, request.ReturnSession == true, options) : Problems.From(http, error);
+    }
+
+    private static async Task<IResult> ListPasskeysAsync(HttpContext http, PasskeyService passkeys)
+    {
+        string userId = http.GetPrincipal().UserId ?? "";
+        IReadOnlyList<PasskeyRecord> list = userId.Length == 0 ? [] : await passkeys.ListAsync(userId, http.RequestAborted);
+        return TypedResults.Json(new PageDto<PasskeyDto>([.. list.Select(Mappers.ToDto)], null), ApiJsonContext.Default.PageDtoPasskeyDto);
+    }
+
+    private static async Task<IResult> PasskeyCreationOptionsAsync(HttpContext http, PasskeyService passkeys, BackendOptions options)
+    {
+        Result<CreationOptions> result = await passkeys.BeginRegistrationAsync(http.GetPrincipal(), PasskeyContextOf(http, options), http.RequestAborted);
+        if (!result.TryGet(out CreationOptions? o, out FleetError? error))
+        {
+            return Problems.From(http, error);
+        }
+
+        http.Response.Headers.CacheControl = "no-store";
+        return TypedResults.Json(new PasskeyCreationOptionsDto(o.Challenge, o.RpId, o.RpName, o.UserId, o.UserName, o.ExcludeCredentials, o.TimeoutMs), ApiJsonContext.Default.PasskeyCreationOptionsDto);
+    }
+
+    private static async Task<IResult> RegisterPasskeyAsync(HttpContext http, RegisterPasskeyRequest request, PasskeyService passkeys, BackendOptions options)
+    {
+        Result<PasskeyRecord> result = await passkeys.RegisterAsync(
+            http.GetPrincipal(), new PasskeyRegistration(request.Name ?? "", request.CredentialId ?? "", request.AttestationObject ?? "", request.ClientDataJson ?? "", request.Transports), PasskeyContextOf(http, options), http.RequestAborted);
+        return result.TryGet(out PasskeyRecord? record, out FleetError? error)
+            ? TypedResults.Json(Mappers.ToDto(record), ApiJsonContext.Default.PasskeyDto, statusCode: StatusCodes.Status201Created)
+            : Problems.From(http, error);
+    }
+
+    private static async Task<IResult> DeletePasskeyAsync(HttpContext http, PasskeyService passkeys, string id) =>
+        http.GetPrincipal().UserId is { } userId && await passkeys.DeleteAsync(userId, id, http.RequestAborted)
+            ? TypedResults.NoContent()
+            : Problems.Create(http, MoShiroErrors.NotFound, "no such passkey");
+
     private static async Task<IResult> LogoutAsync(HttpContext http, AuthService auth)
     {
         string? bearer = PrincipalResolver.BearerOf(http);