Web Api Owin+Oauth2.0（ClientCredentials）+Jwt Token权限认证控制
OAuth简介
OAuth简单说就是一种授权的协议，只要授权方和被授权方遵守这个协议去写代码提供服务，那双方就是实现了OAuth模式。
OAuth 2.0 四种授权模式：
- 授权码模式（authorization code）
- 简化模式（implicit）
- 密码模式（resource owner password credentials）
- 客户端模式（client credentials）
下面的实列就是 客户端模式（client credentials）
Jwt 简介
JSON Web Token（JWT）是一个开放式标准（RFC 7519），它定义了一种紧凑且自包含的方式，用于在各方之间以JSON对象安全传输信息。这些信息可以通过数字签名进行验证和信任。可以使用秘密（使用HMAC算法）或使用RSA的公钥/私钥对对JWT进行签名。
实列讲解
如上图所示引入对应得Nuget包。
在项目中创建 Startup.cs 文件，添加如下代码：
///
/// Startup
///
public class Startup
{
private readonly HttpConfiguration _httpConfig;
///
/// Initializes a new instance of the
public Startup()
{
_httpConfig = new HttpConfiguration();
}
///
/// Configurations the specified application.
///
/// The application.
public void Configuration(IAppBuilder app)
{
ConfigureOAuthTokenGeneration(app);
ConfigureOAuthTokenConsumption(app);
}
//配置token生成
private void ConfigureOAuthTokenGeneration(IAppBuilder app)
{
var oAuthServerOptions = new OAuthAuthorizationServerOptions
{
//TODO:For Dev enviroment only (on production should be AllowInsecureHttp = false)
AllowInsecureHttp = true,
TokenEndpointPath = new PathString("/oauth/token"),//获取token请求地址
AccessTokenExpireTimeSpan = TimeSpan.FromDays(5),//token过期时间
Provider = new SimpleOAuthProvider(),//token生成服务
AccessTokenFormat = new SimpleJwtFormat()//token生成Jwt格式
};
app.UseOAuthAuthorizationServer(oAuthServerOptions);
app.UseOAuthBearerAuthentication(new OAuthBearerAuthenticationOptions());
}
//配置token使用
private void ConfigureOAuthTokenConsumption(IAppBuilder app)
{
var issuer = ConfigurationManager.AppSettings["oauth:Issuer"];
var audienceIds = ConfigurationManager.AppSettings["oauth:Audiences"];
var audienceSecrets = ConfigurationManager.AppSettings["oauth:Secrets"];
var allowedAudiences = audienceIds.Split(new[] {","}, StringSplitOptions.RemoveEmptyEntries);
var base64Keys = audienceSecrets.Split(new[] {","}, StringSplitOptions.RemoveEmptyEntries);
var keys = base64Keys.Select(s => TextEncodings.Base64Url.Decode(s)).ToList();
app.UseJwtBearerAuthentication(new JwtBearerAuthenticationOptions
{
AuthenticationMode = AuthenticationMode.Active,
AllowedAudiences = allowedAudiences,
IssuerSecurityTokenProviders = new IIssuerSecurityTokenProvider[]
{
new SymmetricKeyIssuerSecurityTokenProvider(issuer, keys)
},
Provider = new SimpleOAuthBearerAuthenticationProvider("access_token")
});
}
}
SimpleOAuthProvider示例代码：
public class SimpleOAuthProvider : OAuthAuthorizationServerProvider
{
public override Task ValidateClientAuthentication(OAuthValidateClientAuthenticationContext context)
{
string clientId;
string clientSecret;
if (!context.TryGetBasicCredentials(out clientId, out clientSecret))
context.TryGetFormCredentials(out clientId, out clientSecret);
var authDbContext = new ExternalInterfaceBaseDbContext();
ICustomerRepository customerRepository = new CustomerRepository(authDbContext);
if (context.ClientId == null)
{
context.SetError("invalid_client", "The client_id is not set.");
return Task.FromResult使用Oauth2.0 ClientCredentials 模式获取token，授予客户凭证 。注意：不同得模式重写。GrantResourceOwnerCredentials 内部可以调用外部服务，以进行对用户账户信息的验证。
SimpleJwtFormat 示例代码：
public class SimpleJwtFormat : ISecureDataFormat
{
private const string AudiencePropertyKey = "audience";
private readonly string _issuer;
private readonly string _audienceSecrets;
public SimpleJwtFormat()
{
_issuer = ConfigurationManager.AppSettings["oauth:Issuer"];
_audienceSecrets = ConfigurationManager.AppSettings["oauth:Secrets"];
}
public string Protect(AuthenticationTicket data)
{
if (data == null)
throw new ArgumentNullException(nameof(data));
var properties = data.Properties;
var propertityDictionary = properties.Dictionary;
var audienceId = propertityDictionary.ContainsKey(AudiencePropertyKey)
? propertityDictionary[AudiencePropertyKey]
: null;
if (string.IsNullOrWhiteSpace(audienceId))
throw new InvalidOperationException("AuthenticationTicket.Properties does not include audience.");
if (properties.IssuedUtc == null)
throw new InvalidOperationException("AuthenticationTicket.Properties does not include issued.");
if (properties.ExpiresUtc == null)
throw new InvalidOperationException("AuthenticationTicket.Properties does not include expires.");
var issued = properties.IssuedUtc.Value.UtcDateTime;
var expires = properties.ExpiresUtc.Value.UtcDateTime;
//TODO:
//var authDbContext = new InstrumentDbContext();
//var audienceRepository = new AudienceRepository(authDbContext);
//var audience = audienceRepository.Get(audienceId);
var decodedSecret = TextEncodings.Base64Url.Decode(_audienceSecrets);
var signingCredentials = new HmacSigningCredentials(decodedSecret);
var token = new JwtSecurityToken(_issuer, audienceId, data.Identity.Claims, issued, expires,
signingCredentials);
var handler = new JwtSecurityTokenHandler();
var jwt = handler.WriteToken(token);
return jwt;
}
} 根据授权Id生成Jwt Token返回。
SimpleOAuthBearerAuthenticationProvider 示例代码：
public class SimpleOAuthBearerAuthenticationProvider : OAuthBearerAuthenticationProvider
{
private readonly string _accessTokenName;
public SimpleOAuthBearerAuthenticationProvider(string accessTokenName)
{
_accessTokenName = accessTokenName;
}
public override Task RequestToken(OAuthRequestTokenContext context)
{
var token = context.Request.Query.Get(_accessTokenName);
if (!string.IsNullOrEmpty(token))
context.Token = token;
return Task.FromResult配置AccessToken使用。
到这里权限认证代码基本完成，最后就是在控制器或者方法上配置权限控制特性 [Authorize]。
[Authorize]
[RoutePrefix("api/areas")]
public class AreaController : ApiController这样Web Api Owin + Oauth2.0 + Jwt Token 的权限认证框架就已经搭好了。
