/// <summary>
/// Determines whether the <see cref="ECDsaSecurityKey"/> can compute a JWK thumbprint.
/// </summary>
/// <returns><c>true</c> if JWK thumbprint can be computed; otherwise, <c>false</c>.</returns>
/// <remarks>https://tools.ietf.org/html/rfc7638</remarks>
public override bool CanComputeJwkThumbprint()
{
#if NET472 || NETSTANDARD2_0
if (ECDsaAdapter.SupportsECParameters())
{
return(true);
}
#endif
return(false);
}
/// <summary>
/// Computes a sha256 hash over the <see cref="ECDsaSecurityKey"/>.
/// </summary>
/// <returns>A JWK thumbprint.</returns>
/// <remarks>https://tools.ietf.org/html/rfc7638</remarks>
public override byte[] ComputeJwkThumbprint()
{
#if NET472 || NETSTANDARD2_0
if (ECDsaAdapter.SupportsECParameters())
{
ECParameters parameters = ECDsa.ExportParameters(false);
var canonicalJwk = $@"{{""{JsonWebKeyParameterNames.Crv}"":""{ECDsaAdapter.GetCrvParameterValue(parameters.Curve)}"",""{JsonWebKeyParameterNames.Kty}"":""{JsonWebAlgorithmsKeyTypes.EllipticCurve}"",""{JsonWebKeyParameterNames.X}"":""{Base64UrlEncoder.Encode(parameters.Q.X)}"",""{JsonWebKeyParameterNames.Y}"":""{Base64UrlEncoder.Encode(parameters.Q.Y)}""}}";
return(Utility.GenerateSha256Hash(canonicalJwk));
}
#endif
throw LogHelper.LogExceptionMessage(new PlatformNotSupportedException(LogMessages.IDX10695));
}
/// <summary>
/// Converts a <see cref="ECDsaSecurityKey"/> into a <see cref="JsonWebKey"/>
/// </summary>
/// <param name="key">an <see cref="ECDsaSecurityKey"/> to convert.</param>
/// <returns>a <see cref="JsonWebKey"/></returns>
/// <exception cref="ArgumentNullException">if <paramref name="key"/>is null.</exception>
public static JsonWebKey ConvertFromECDsaSecurityKey(ECDsaSecurityKey key)
{
if (!ECDsaAdapter.SupportsECParameters())
{
throw LogHelper.LogExceptionMessage(new PlatformNotSupportedException(LogMessages.IDX10695));
}
if (key == null)
{
throw LogHelper.LogArgumentNullException(nameof(key));
}
if (key.ECDsa == null)
{
throw LogHelper.LogArgumentNullException(nameof(key.ECDsa));
}
ECParameters parameters;
try
{
parameters = key.ECDsa.ExportParameters(true);
}
catch
{
parameters = key.ECDsa.ExportParameters(false);
}
return(new JsonWebKey
{
Crv = ECDsaAdapter.GetCrvParameterValue(parameters.Curve),
X = parameters.Q.X != null?Base64UrlEncoder.Encode(parameters.Q.X) : null,
Y = parameters.Q.Y != null?Base64UrlEncoder.Encode(parameters.Q.Y) : null,
D = parameters.D != null?Base64UrlEncoder.Encode(parameters.D) : null,
Kty = JsonWebAlgorithmsKeyTypes.EllipticCurve,
Kid = key.KeyId,
ConvertedSecurityKey = key
});
}