Creates an asymmetric key, signs a JWT and validates the signature

jwt-token-sign-validate-asymmetric.linq

// https://medium.com/dev-genius/jwt-authentication-in-asp-net-core-e67dca9ae3e8

var rsa = RSA.Create();
var keyPair = (
	prv: rsa.ExportRSAPrivateKey(),
	pub: rsa.ExportRSAPublicKey()
);

// create token and sign it with private key
var rsa_signer = RSA.Create();
rsa_signer.ImportRSAPrivateKey(source: keyPair.prv, bytesRead: out int _);

var signingCredentials = new SigningCredentials(
   key: new RsaSecurityKey(rsa_signer),
   algorithm: SecurityAlgorithms.RsaSha256 // Important to use RSA version of the SHA algo 
);

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 rsa_validater = RSA.Create();
rsa_validater.ImportRSAPublicKey(source: keyPair.pub, bytesRead: out int _);

var principal = new JwtSecurityTokenHandler().ValidateToken(encodedSignedToken, new TokenValidationParameters
{
	ValidateLifetime = true,
	ValidateAudience = true,
	ValidateIssuer = true,
	ValidIssuer = "issuer",
	ValidAudience = "audience",
	IssuerSigningKey = new RsaSecurityKey(rsa_validater)
}, out var validatedToken);

principal.Dump("Validated principal");