ASP.NET Core中使用自定义验证属性控制访问权限
在应用中，有时我们需要对访问的客户端进行有效性验证，只有提供有效凭证（AccessToken）的终端应用能访问我们的受控站点（如WebAPI站点），此时我们可以通过验证属性的方法来解决。
一、public class Startup的配置：
//启用跨域访问（不同端口也是跨域）
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());
});
//启用自定义属性以便对控制器或Action进行[TerminalApp()]定义。
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传输
app.UseCors("AllowOriginOtherBis"); //根据定义启用跨域设置
三、示例WebApi项目结构：
四、主要代码（我采用的从数据库进行验证）：
[AttributeUsage(AttributeTargets.Class | AttributeTargets.Method, AllowMultiple = true)] internal class TerminalAppAttribute : AuthorizeAttribute { public string AppID { get; } /// <summary> /// 指定客户端访问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; //如果取不到身份验证信息，并且不允许匿名访问，则返回未验证403 if (context.Resource is AuthorizationFilterContext filterContext && filterContext.ActionDescriptor is ControllerActionDescriptor descriptor) { //先判断是否是匿名访问, if (descriptor != null) { var actionAttributes = descriptor.MethodInfo.GetCustomAttributes(inherit: true); bool isAnonymous = actionAttributes.Any(a => a is AllowAnonymousAttribute); //非匿名的方法,链接中添加accesstoken值 if (isAnonymous) { context.Succeed(requirement); return Task.CompletedTask; } else { //url获取access_token //从AuthorizationHandlerContext转成HttpContext，以便取出表求信息 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) { //当不指定具体的客户端AppID仅运用验证属性时默认所有客户端都接受 if (attributes.ToArray().ToString()=="") { //任意一个在数据库列表中的App都可以运行,否则先判断提交的APPID与需要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("客户端应用未在服务端登记或未被授权运用当前功能."); return HandleBlockedAsync(context, requirement, errorMsg); } } } //如果未指定attributes，则表示任何一个终端服务都可以调用服务, 在验证区域验证终端提供的ID是否匹配数据库记录 string valRst = ValidateToken(requestAppID, requestAccessToken); if (string.IsNullOrEmpty(valRst)) { context.Succeed(requirement); return Task.CompletedTask; } else { errorMsg = ReturnStd.NotAuthorize("AccessToken验证失败(" + 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类型不匹配."); return HandleBlockedAsync(context, requirement, errorMsg); } errorMsg = ReturnStd.NotAuthorize("未知错误."); return HandleBlockedAsync(context,requirement, errorMsg); } //校验票据（数据库数据匹配） /// <summary> /// 验证终端服务程序提供的AccessToken是否合法 /// </summary> /// <param name="appID">终端APP的ID</param> /// <param name="accessToken">终端APP利用其自身AppKEY运算出来的AccessToken,与服务器生成的进行比对</param> /// <returns></returns> private string ValidateToken(string appID,string accessToken) { try { DBContextMain dBContext = new DBContextMain(); string appKeyOnServer = string.Empty; //从数据库读取AppID对应的KEY(此KEY为加解密算法的AES_KEY AuthApp authApp = dBContext.AuthApps.FirstOrDefault(a => a.AppID == appID); if (authApp == null) { return "客户端应用没有在云端登记!"; } else { appKeyOnServer = authApp.APPKey; } if (string.IsNullOrEmpty(appKeyOnServer)) { return "客户端应用基础信息有误!"; } string tmpToken = string.Empty; tmpToken = System.Net.WebUtility.UrlDecode(accessToken);//解码相应的Token到原始字符(因其中可能会有+=等特殊字符,必须编码后传递) tmpToken = OCrypto.AES16Decrypt(tmpToken, appKeyOnServer); //使用APPKEY解密并分析 if (string.IsNullOrEmpty(tmpToken)) { return "客户端提交的身份令牌运算为空!"; } else { try { //原始验证码为im_cloud_sv001-appid-ticks格式 //取出时间,与服务器时间对比,超过10秒即拒绝服务 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 "令牌未被许可或已经失效!"; } else { return string.Empty; //成功验证 } } catch (Exception ex) { return "令牌解析出错(" + ex.Message + ")"; } } } catch (Exception ex) { return "令牌解析出错(" + ex.Message + ")"; } } private Task HandleBlockedAsync(AuthorizationHandlerContext context, TerminalAppAuthorizationRequirement requirement, object errorMsg) { var authorizationFilterContext = context.Resource as AuthorizationFilterContext; authorizationFilterContext.Result = new JsonResult(errorMsg) { StatusCode = 202 }; //设置为403会显示不了自定义信息,改为Accepted202,由客户端处理 context.Succeed(requirement); return Task.CompletedTask; } }
internal class TerminalAppAuthorizationRequirement : IAuthorizationRequirement { public TerminalAppAuthorizationRequirement() { } }
五、相应的Token验证代码：
[AutoValidateAntiforgeryToken] //在本控制器内自动启用跨站攻击防护 [Route("api/get_accesstoken")] public class GetAccessTokenController : Controller { //尚未限制访问频率 //返回{"access_token":"ACCESS_TOKEN","expires_in":7200} 有效期2个小时 //错误时返回{"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采用im_cloud_sv001-appid-ticks数字 long timeTk = DateTime.Now.Ticks; //输出毫微秒：633603924670937500 //DateTime dt = new DateTime(timeTk);//可以还原时间 string plToken = "im_cloud1-" + appID + "-" + timeTk; tmpToken = OCrypto.AES16Encrypt(plToken, appKey); //使用APPKEY加密 tmpToken = System.Net.WebUtility.UrlEncode(tmpToken); //编码相应的Token(因其中可能会有+=等特殊字符,必须编码后传递) tmpToken = "{'access_token':'" + tmpToken + "','expires_in':7200}"; return tmpToken; } catch (Exception ex) { return "{'errcode':10001,'errmsg':'" + ex.Message +"'}"; } } }
六、这样，在我们需要控制的地方加上
[TerminalApp()] 即可，这样所有授权的App都能访问，当然，也可以使用[TerminalApp(“app01”)]限定某一个ID为app01的应用访问。
[Area("SYS")] // 路由: api/sys/user
[Produces("application/json")]
[TerminalApp()]
public class UserController : Controller
{
//
}
七、一个CS客户端通过Web API上传数据调用示例：
string postURL = "http://sv12.ato.com/api/sys/user/postnew";
Dictionary<string, string> headerDic2 = new Dictionary<string, string>
{
{ "appid", MainFramework.CloudAppID },
{ "access_token", accessToken }
};
string pushRst = OPWeb.Post(postURL, headerDic2, "POST", sYS_Users);
if (string.IsNullOrEmpty(pushRst))
{
MyMsg.Information("推送成功!");
}
else
{
MyMsg.Information("推送失败!", pushRst);
}
string accessToken = MainFramework.CloudAccessToken;
if (accessToken.IndexOf("ERROR:") >= 0)
{
MyMsg.Information("获取Token出错:" + accessToken);
return;
}
