ASP.NET Core中使用自定義驗證屬性控制訪問許可權
在應用中,有時我們需要對訪問的客戶端進行有效性驗證,只有提供有效憑證(AccessToken)的終端應用能訪問我們的受控站點(如WebAPI站點),此時我們可以通過驗證屬性的方法來解決。
一、public class Startup的配置:
//啟用跨域訪問(不同埠也是跨域) services.AddCors(options => { options.AddPolicy("AllowOriginOtherBis", builder => builder.WithOrigins("https://1.16.9.12:4432", "https://pc12.ato.biz:4432", "https://localhost:44384", "https://1.16.9.12:4432", "https://pc12.ato.biz:4432").AllowAnyMethod().AllowAnyHeader()); });
//啟用自定義屬性以便對控制器或Action進行[TerminalApp()]定義。
services.AddSingleton<IAuthorizationHandler, TerminalAppAuthorizationHandler>(); services.AddAuthorization(options => { options.AddPolicy("TerminalApp", policyBuilder => { policyBuilder.Requirements.Add(new TerminalAppAuthorizationRequirement()); }); });
二、public void Configure(IApplicationBuilder app, IHostingEnvironment env)中的配置:
app.UseHttpsRedirection(); //使用Https傳輸 app.UseCors("AllowOriginOtherBis"); //根據定義啟用跨域設定
三、示例WebApi專案結構:
四、主要程式碼(我採用的從資料庫進行驗證):
[AttributeUsage(AttributeTargets.Class | AttributeTargets.Method, AllowMultiple = trueTerminalAppAttribute.cs)] internal class TerminalAppAttribute : AuthorizeAttribute { public string AppID { get; } /// <summary> /// 指定客戶端訪問API /// </summary> /// <param name="appID"></param> public TerminalAppAttribute(string appID="") : base("TerminalApp") { AppID = appID; } }
public abstract class AttributeAuthorizationHandler<TRequirement, TAttribute> : AuthorizationHandler<TRequirement> where TRequirement : IAuthorizationRequirement where TAttribute : Attribute { protected override Task HandleRequirementAsync(AuthorizationHandlerContext context, TRequirement requirement) { var attributes = new List<TAttribute>(); if ((context.Resource as AuthorizationFilterContext)?.ActionDescriptor is ControllerActionDescriptor action) { attributes.AddRange(GetAttributes(action.ControllerTypeInfo.UnderlyingSystemType)); attributes.AddRange(GetAttributes(action.MethodInfo)); } return HandleRequirementAsync(context, requirement, attributes); } protected abstract Task HandleRequirementAsync(AuthorizationHandlerContext context, TRequirement requirement, IEnumerable<TAttribute> attributes); private static IEnumerable<TAttribute> GetAttributes(MemberInfo memberInfo) { return memberInfo.GetCustomAttributes(typeof(TAttribute), false).Cast<TAttribute>(); } } internal class TerminalAppAuthorizationHandler : AttributeAuthorizationHandler<TerminalAppAuthorizationRequirement,TerminalAppAttribute> { protected override Task HandleRequirementAsync(AuthorizationHandlerContext context, TerminalAppAuthorizationRequirement requirement, IEnumerable<TerminalAppAttribute> attributes) { object errorMsg = string.Empty; //如果取不到身份驗證資訊,並且不允許匿名訪問,則返回未驗證403 if (context.Resource is AuthorizationFilterContext filterContext && filterContext.ActionDescriptor is ControllerActionDescriptor descriptor) { //先判斷是否是匿名訪問, if (descriptor != null) { var actionAttributes = descriptor.MethodInfo.GetCustomAttributes(inherit: true); bool isAnonymous = actionAttributes.Any(a => a is AllowAnonymousAttribute); //非匿名的方法,連結中新增accesstoken值 if (isAnonymous) { context.Succeed(requirement); return Task.CompletedTask; } else { //url獲取access_token //從AuthorizationHandlerContext轉成HttpContext,以便取出表求資訊 var httpContext = (context.Resource as AuthorizationFilterContext).HttpContext; //var questUrl = httpContext.Request.Path.Value.ToLower(); string requestAppID = httpContext.Request.Headers["appid"]; string requestAccessToken = httpContext.Request.Headers["access_token"]; if ((!string.IsNullOrEmpty(requestAppID)) && (!string.IsNullOrEmpty(requestAccessToken))) { if (attributes != null) { //當不指定具體的客戶端AppID僅運用驗證屬性時預設所有客戶端都接受 if (attributes.ToArray().ToString()=="") { //任意一個在資料庫列表中的App都可以執行,否則先判斷提交的APPID與需要ID是否相符 bool mat = false; foreach (var terminalAppAttribute in attributes) { if (terminalAppAttribute.AppID == requestAppID) { mat = true; break; } } if (!mat) { errorMsg = ReturnStd.NotAuthorize("客戶端應用未在服務端登記或未被授權運用當前功能."); return HandleBlockedAsync(context, requirement, errorMsg); } } } //如果未指定attributes,則表示任何一個終端服務都可以呼叫服務, 在驗證區域驗證終端提供的ID是否匹配資料庫記錄 string valRst = ValidateToken(requestAppID, requestAccessToken); if (string.IsNullOrEmpty(valRst)) { context.Succeed(requirement); return Task.CompletedTask; } else { errorMsg = ReturnStd.NotAuthorize("AccessToken驗證失敗(" + valRst + ")","91"); return HandleBlockedAsync(context, requirement, errorMsg); } } else { errorMsg = ReturnStd.NotAuthorize("未提供AppID或Token."); return HandleBlockedAsync(context, requirement, errorMsg); //return Task.CompletedTask; } } } } else { errorMsg = ReturnStd.NotAuthorize("FilterContext型別不匹配."); return HandleBlockedAsync(context, requirement, errorMsg); } errorMsg = ReturnStd.NotAuthorize("未知錯誤."); return HandleBlockedAsync(context,requirement, errorMsg); } //校驗票據(資料庫資料匹配) /// <summary> /// 驗證終端服務程式提供的AccessToken是否合法 /// </summary> /// <param name="appID">終端APP的ID</param> /// <param name="accessToken">終端APP利用其自身AppKEY運算出來的AccessToken,與伺服器生成的進行比對</param> /// <returns></returns> private string ValidateToken(string appID,string accessToken) { try { DBContextMain dBContext = new DBContextMain(); string appKeyOnServer = string.Empty; //從資料庫讀取AppID對應的KEY(此KEY為加解密演算法的AES_KEY AuthApp authApp = dBContext.AuthApps.FirstOrDefault(a => a.AppID == appID); if (authApp == null) { return "客戶端應用沒有在雲端登記!"; } else { appKeyOnServer = authApp.APPKey; } if (string.IsNullOrEmpty(appKeyOnServer)) { return "客戶端應用基礎資訊有誤!"; } string tmpToken = string.Empty; tmpToken = System.Net.WebUtility.UrlDecode(accessToken);//解碼相應的Token到原始字元(因其中可能會有+=等特殊字元,必須編碼後傳遞) tmpToken = OCrypto.AES16Decrypt(tmpToken, appKeyOnServer); //使用APPKEY解密並分析 if (string.IsNullOrEmpty(tmpToken)) { return "客戶端提交的身份令牌運算為空!"; } else { try { //原始驗證碼為im_cloud_sv001-appid-ticks格式 //取出時間,與伺服器時間對比,超過10秒即拒絕服務 long tmpTime =Convert.ToInt64(tmpToken.Substring(tmpToken.LastIndexOf("-")+1)); //DateTime dt = DateTime.ParseExact(tmpTime, "yyyyMMddHHmmss", CultureInfo.CurrentCulture); DateTime dt= new DateTime(tmpTime); bool IsInTimeSpan = (Convert.ToDouble(ODateTime.DateDiffSeconds(dt, DateTime.Now)) <= 7200); bool IsInternalApp = (tmpToken.IndexOf("im_cloud_sv001-") >= 0); if (!IsInternalApp || !IsInTimeSpan) { return "令牌未被許可或已經失效!"; } else { return string.Empty; //成功驗證 } } catch (Exception ex) { return "令牌解析出錯(" + ex.Message + ")"; } } } catch (Exception ex) { return "令牌解析出錯(" + ex.Message + ")"; } } private Task HandleBlockedAsync(AuthorizationHandlerContext context, TerminalAppAuthorizationRequirement requirement, object errorMsg) { var authorizationFilterContext = context.Resource as AuthorizationFilterContext; authorizationFilterContext.Result = new JsonResult(errorMsg) { StatusCode = 202 }; //設定為403會顯示不了自定義資訊,改為Accepted202,由客戶端處理 context.Succeed(requirement); return Task.CompletedTask; } }TerminalAppAuthorizationHandler.cs
internal class TerminalAppAuthorizationRequirement : IAuthorizationRequirement { public TerminalAppAuthorizationRequirement() { } }TerminalAppAuthorizationRequirement.cs
五、相應的Token驗證程式碼:
[AutoValidateAntiforgeryToken] //在本控制器內自動啟用跨站攻擊防護 [Route("api/get_accesstoken")] public class GetAccessTokenController : Controller { //尚未限制訪問頻率 //返回{"access_token":"ACCESS_TOKEN","expires_in":7200} 有效期2個小時 //錯誤時返回{"errcode":40013,"errmsg":"invalid appid"} [AllowAnonymous] public ActionResult<string> Get() { try { string tmpToken = string.Empty; string appID = HttpContext.Request.Headers["appid"]; string appKey = HttpContext.Request.Headers["appkey"]; if ((appID.Length < 5) || appKey.Length != 32) { return "{'errcode':10000,'errmsg':'appid或appkey未提供'}"; } //token採用im_cloud_sv001-appid-ticks數字 long timeTk = DateTime.Now.Ticks; //輸出毫微秒:633603924670937500 //DateTime dt = new DateTime(timeTk);//可以還原時間 string plToken = "im_cloud1-" + appID + "-" + timeTk; tmpToken = OCrypto.AES16Encrypt(plToken, appKey); //使用APPKEY加密 tmpToken = System.Net.WebUtility.UrlEncode(tmpToken); //編碼相應的Token(因其中可能會有+=等特殊字元,必須編碼後傳遞) tmpToken = "{'access_token':'" + tmpToken + "','expires_in':7200}"; return tmpToken; } catch (Exception ex) { return "{'errcode':10001,'errmsg':'" + ex.Message +"'}"; } } }GetAccessTokenController.cs
六、這樣,在我們需要控制的地方加上
[TerminalApp()] 即可,這樣所有授權的App都能訪問,當然,也可以使用[TerminalApp(“app01”)]限定某一個ID為app01的應用訪問。
[Area("SYS")] // 路由: api/sys/user [Produces("application/json")] [TerminalApp()] public class UserController : Controller { // }