aspnettokens-block3.cs

[Route(Constants.KeysRoute)]
[Consumes("application/json")]
[Produces("application/json")]
[ApiController]
public class KeySetController : ControllerBase
{
    private readonly IEnumerable<X509Certificate2> signingCertificates;

    public KeySetController(
        // add this to dependency injection
        IEnumerable<X509Certificate2> signingCertificates)
    {
        this.signingCertificates = signingCertificates;
    }

    [HttpGet]
    public async Task<IActionResult> GetKeySetAsync(CancellationToken cancellationToken)
    {
        var jwks = new JsonWebKeySet();

        foreach (var certificate in this.signingCertificates)
        {
            var rsaParameters = ((RSA)certificate.PublicKey.Key).ExportParameters(false);

            var jwk = new JsonWebKey()
            {
                // https://tools.ietf.org/html/rfc7517#section-4
                Kty = certificate.PublicKey.Key.KeyExchangeAlgorithm,
                Use = "sig",
                Kid = certificate.Thumbprint,
                X5t = certificate.Thumbprint,

                // https://tools.ietf.org/html/rfc7517#appendix-B
                N = Convert.ToBase64String(rsaParameters.Modulus),
                E = Convert.ToBase64String(rsaParameters.Exponent),
            };

            jwks.Keys.Add(jwk);
        }

        return Ok(jwks);
    }
}