Sample codes for the blog post: Generate/Validate JSON Web Tokens(JWT) in ASP.NET Core

account-login.cs

var securityKey = new SymmetricSecurityKey(
        Encoding.UTF8.GetBytes("7h!$S40u1d83@$7r0n9P@5$Word"));
var header = new JwtHeader(
        new SigningCredentials(
                securityKey,
                SecurityAlgorithms.HmacSha512Signature
        ));

var claims = new[]
{
    new Claim(ClaimTypes.NameIdentifier, "user1"),
    new Claim(ClaimTypes.Role, "admin"),
};
var payload = new JwtPayload(
                        issuer: "http://localhost:6001",
                        audience: "my-api",
                        claims: claims, null,
                        expires: DateTime.UtcNow.AddDays(7),null);

var token = new JwtSecurityToken(header, payload);

var tokenHandler = new JwtSecurityTokenHandler();

return tokenHandler.WriteToken(token);

add-package.bash

dotnet add package Microsoft.AspNetCore.Authentication.JwtBearer --version 3.1.8

configure-services.cs

services.AddAuthentication(JwtBearerDefaults.AuthenticationScheme)
        .AddJwtBearer(JwtBearerDefaults.AuthenticationScheme, options =>
        {
            options.TokenValidationParameters = new TokenValidationParameters
            {
                ValidateIssuerSigningKey = true,
                ValidateIssuer = true,
                ValidateAudience = true,
                ValidIssuer = "http://localhost:6001",
                ValidAudience = "my-api",
                IssuerSigningKey = new SymmetricSecurityKey(
                    Encoding.UTF8.GetBytes("7h!$S40u1d83@$7r0n9P@5$Word"))
            };

            options.Events = new JwtBearerEvents
            {
                OnMessageReceived = ValidateToken
            };
        });

curl-account-login.bash

curl -X POST "https://localhost:6001/Account/login" -H "accept: application/json" -H "Content-Type: application/json" -d "{\"username\":\"shahab\",\"password\":\"somepassword\"}"

validate-token.cs

public static Task ValidateToken(MessageReceivedContext context)
{
    try
    {
        context.Token = GetToken(context.Request);

        var tokenHandler = new JwtSecurityTokenHandler();
        tokenHandler.ValidateToken(context.Token, context.Options.TokenValidationParameters, out var validatedToken);

        var jwtSecurityToken = validatedToken as JwtSecurityToken;

        context.Principal = new ClaimsPrincipal();

        var claimsIdentity = new ClaimsIdentity(jwtSecurityToken.Claims.ToList(),
                "JwtBearerToken", ClaimTypes.NameIdentifier, ClaimTypes.Role);
        context.Principal.AddIdentity(claimsIdentity);

        context.Success();

        return Task.CompletedTask;
    }
    catch (Exception e)
    {
        context.Fail(e);
    }

    return Task.CompletedTask;
}