从WebAPI控制器获取声明 - JWT令牌,

Question

我已经构建了一个在ASP.NET Core中使用JWT承载认证的应用程序.在进行身份验证时,我定义了一些我需要在另一个WebAPI控制器中读取的自定义声明,以便执行某些操作.

任何想法我如何实现这一目标？

我的代码如下所示:(代码已经简化)

public async Task<IActionResult> AuthenticateAsync([FromBody] UserModel user)
    {
        ..............

                var tokenHandler = new JwtSecurityTokenHandler();
                var key = Encoding.ASCII.GetBytes(_appSettings.Secret);
                var tokenDescriptor = new SecurityTokenDescriptor
                {
                    Subject = new ClaimsIdentity(new Claim[]
                    {
                        new Claim("userSecurityKey", userDeserialized.SecurityKey.ToString()),
                        new Claim("timeStamp",timeStamp),
                        new Claim("verificationKey",userDeserialized.VerificationKey.ToString())

                    }),
                    Expires = DateTime.UtcNow.AddDays(7),
                    SigningCredentials = new SigningCredentials(new SymmetricSecurityKey(key),
                        SecurityAlgorithms.HmacSha256Signature)
                };
                var token = tokenHandler.CreateToken(tokenDescriptor);
                var tokenString = tokenHandler.WriteToken(token);

     .................                           

    }

另一个控制器:(需要阅读"verificationKey"声明.)

    [HttpGet]
    [Route("getcandidate")]
    public async Task<IActionResult> GetCandidateAsync()
    {

        try
        {
             ............    


            var verificationKey = //TODO: GET VerificationKey FROM THE TOKEN

            var verificationRecord = await service.GetVerificationRecordAsync(verificationKey);

            .................

        }
        catch (Exception)
        {
            return NotFound();
        }
    }

Answer 1

您应该能够在控制器中检索此类声明

var identity = HttpContext.User.Identity as ClaimsIdentity;
if (identity != null)
{
    IEnumerable<Claim> claims = identity.Claims; 
    // or
    identity.FindFirst("ClaimName").Value;

}

如果您愿意,您可以为IPrincipal接口编写扩展方法并使用上面的代码检索声明,然后使用(例如)检索它们

HttpContext.User.Identity.MethodName();

为了完整的答案.要解码JWT令牌,让我们编写一个方法来验证令牌并提取信息.

public static ClaimsPrincipal ValidateToken(string jwtToken)
    {
        IdentityModelEventSource.ShowPII = true;

        SecurityToken validatedToken;
        TokenValidationParameters validationParameters = new TokenValidationParameters();

        validationParameters.ValidateLifetime = true;

        validationParameters.ValidAudience = _audience.ToLower();
        validationParameters.ValidIssuer = _issuer.ToLower();
        validationParameters.IssuerSigningKey = new Microsoft.IdentityModel.Tokens.SymmetricSecurityKey(Encoding.UTF8.GetBytes(_appSettings.Secret));

        ClaimsPrincipal principal = new JwtSecurityTokenHandler().ValidateToken(jwtToken, validationParameters, out validatedToken);


        return principal;
    }

现在我们可以使用以下方法验证和提取声明:

ValidateToken(tokenString)?.FindFirst("ClaimName")?.Value

您应该注意,null如果验证失败,ValidateToken方法将返回值.

Answer 2

解码 JWT 并获取声明的一种方法是使用System.IdentityModel.Tokens

public string getJWTTokenClaim(string token, string claimName)
{
    try
    {
        var tokenHandler = new JwtSecurityTokenHandler();
        var securityToken = (JwtSecurityToken)tokenHandler.ReadToken(token);
        var claimValue = securityToken.Claims.FirstOrDefault(c => c.Type == claimName)?.Value;
        return claimValue;
    }
    catch (Exception)
    {
        //TODO: Logger.Error
        return null;
    }
}

Answer 3

// Cast to ClaimsIdentity.
var identity = HttpContext.User.Identity as ClaimsIdentity;

// Gets list of claims.
IEnumerable<Claim> claim = identity.Claims; 

// Gets name from claims. Generally it's an email address.
var usernameClaim = claim
    .Where(x => x.Type == ClaimTypes.Name)
    .FirstOrDefault();

// Finds user.
var userName = await _userManager
    .FindByNameAsync(usernameClaim.Value);

if (userName == null)
{
    return BadRequest();
}

// The rest of your code goes here...

Answer 4

在通过 JwtBearerDefaults 方案授权的 net core 2 的任何控制器中，您可以使用：

 [Authorize(AuthenticationSchemes = JwtBearerDefaults.AuthenticationScheme)]
 public ActionResult Index()
    {
        var user = User.FindFirst("Name").Value;
        //or if u want the list of claims
        var claims = User.Claims;

        return View();
    }