本篇文章给大家介绍详解ASP.NET Core使用自定义验证属性控制访问权限。
大家都知道在应用中，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。
方法如下
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());
});
});
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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
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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;
}
}
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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;
}
}
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internal class TerminalAppAuthorizationRequirement : IAuthorizationRequirement
{
public TerminalAppAuthorizationRequirement()
{
}
}
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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 +"'}";
}
}
}
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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
{
//
}
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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);
}
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string accessToken = MainFramework.CloudAccessToken;
if (accessToken.IndexOf("ERROR:") >= 0)
{
MyMsg.Information("获取Token出错:" + accessToken);
return;
}
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