Creates a symmetric key, signs a JWT and validates the signature

jwt-token-sign-validate-symmetric.linq

// https://weblog.west-wind.com/posts/2021/Mar/09/Role-based-JWT-Tokens-in-ASPNET-Core

// create token and sign it with key
var signingCredentials = new SigningCredentials(
	key: new SymmetricSecurityKey(Encoding.UTF8.GetBytes("Thats a sufficiently long key")), 
	algorithm: SecurityAlgorithms.HmacSha256);
	
var token = new JwtSecurityToken(
	issuer:"issuer",
	audience: "audience",
	claims: new List<Claim>
	{
		new Claim("username", "username")
	},
	notBefore: DateTime.UtcNow, 
	expires: DateTime.UtcNow.AddDays(1),
	signingCredentials:signingCredentials);

var encodedSignedToken = new JwtSecurityTokenHandler().WriteToken(token).Dump("Encoded signed token");

// validate the token
var principal =  new JwtSecurityTokenHandler().ValidateToken(encodedSignedToken, new TokenValidationParameters
{
	ValidateLifetime = true, 
	ValidateAudience = true,
	ValidateIssuer = true,
	ValidIssuer = "issuer",
	ValidAudience = "audience",
	IssuerSigningKey = new SymmetricSecurityKey(Encoding.UTF8.GetBytes("Thats a sufficiently long key"))
}, out var validatedToken);

principal.Dump("Validated principal");