UseJwtBearerAuthentication does not get User.Identity.Name populated : <p>I am trying to use <code>JWT</code> for authentication mechanism in <code>ASP.NET Core Web API</code> project. Suppose this project has not <code>MVC</code> part and does not use cookie authentication. I have created my code based on <a href="https://goblincoding.com/2016/07/03/issuing-and-authenticating-jwt-tokens-in-asp-net-core-webapi-part-i/" rel="noreferrer">this guide</a>. </p>

<p>Login works good and protection with <code>[Authorize]</code> attribute works ok but <code>User.Identity.Name</code> is <code>null</code>. How can I fix this?</p>

<p>My code:</p>

<pre><code>public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory)
{
    var jwtAppSettingOptions = Configuration.GetSection(nameof(JwtIssuerOptions));
    var tokenValidationParameters = new TokenValidationParameters
    {
        ValidateIssuer = true,
        ValidIssuer = jwtAppSettingOptions[nameof(JwtIssuerOptions.Issuer)],

        ValidateAudience = true,
        ValidAudience = jwtAppSettingOptions[nameof(JwtIssuerOptions.Audience)],

        ValidateIssuerSigningKey = true,
        IssuerSigningKey = _signingKey,

        RequireExpirationTime = true,
        ValidateLifetime = true,

        ClockSkew = TimeSpan.Zero
    };

    app.UseJwtBearerAuthentication(new JwtBearerOptions
    {
        AutomaticAuthenticate = true,
        AutomaticChallenge = true,
        TokenValidationParameters = tokenValidationParameters,
        AuthenticationScheme = JwtBearerDefaults.AuthenticationScheme
    });

    app.UseMvc(routes =&gt;
    {
        routes.MapRoute(
            name: "default",
            template: "{controller=Home}/{action=Index}/{id?}");
    });
}
</code></pre>

<hr>

<pre><code>    [HttpPost]
    [AllowAnonymous]
    [Route("Login")]
    public async Task&lt;IActionResult&gt; Login([FromForm] ApplicationUser applicationUser)
    {
        //assume user/pass are checked and are ok

        _logger.LogInformation(1, "API User logged in.");
        var user = await _userManager.FindByNameAsync(applicationUser.UserName);
        var roles = await _userManager.GetRolesAsync(user);

        var claims = new List&lt;Claim&gt;
        {
            new Claim(JwtRegisteredClaimNames.Sub, applicationUser.UserName),
            new Claim(ClaimTypes.NameIdentifier, applicationUser.UserName),
            new Claim(JwtRegisteredClaimNames.Jti, await _jwtOptions.JtiGenerator()),
            new Claim(JwtRegisteredClaimNames.Iat,
                    ToUnixEpochDate(_jwtOptions.IssuedAt).ToString(),
                    ClaimValueTypes.Integer64),
                    new Claim("Claim", "Value")
        };

        if (roles != null)
            foreach (var role in roles)
                claims.Add(new Claim("role", role));

        // Create the JWT security token and encode it.
        var jwt = new JwtSecurityToken(
            issuer: _jwtOptions.Issuer,
            audience: _jwtOptions.Audience,
            claims: claims,
            notBefore: _jwtOptions.NotBefore,
            expires: _jwtOptions.Expiration,
            signingCredentials: _jwtOptions.SigningCredentials);

        var encodedJwt = new JwtSecurityTokenHandler().WriteToken(jwt);

        // Serialize and return the response
        var response = new
        {
            access_token = encodedJwt,
            expires_in = (int)_jwtOptions.ValidFor.TotalSeconds
        };

        var json = JsonConvert.SerializeObject(response, _serializerSettings);
        return new OkObjectResult(json);
    }
</code></pre>
