/// <summary>
/// Computes the DNS value for the <paramref name="challenge"/>.
/// </summary>
/// <param name="challenge">The challenge.</param>
/// <param name="key">The key.</param>
/// <returns>The value for the text DNS record.</returns>
public static string ComputeDnsValue(this ChallengeEntity challenge, IAccountKey key)
{
var keyAuthString = challenge.ComputeKeyAuthorization(key);
var keyAuthBytes = Encoding.UTF8.GetBytes(keyAuthString);
var sha256 = new Sha256Digest();
var hashed = new byte[sha256.GetDigestSize()];
sha256.BlockUpdate(keyAuthBytes, 0, keyAuthBytes.Length);
sha256.DoFinal(hashed, 0);
var dnsValue = JwsConvert.ToBase64String(hashed);
return(dnsValue);
}
public async Task CanComputeDnsKeyAuth()
{
var challenge = new ChallengeEntity
{
Token = "6csJt_REONi1guIpCqdw6wCP5hL8YxtOhTCETu7ECYY",
Type = "dns-01"
};
var keyAuth = challenge.ComputeDnsValue(await Helper.LoadkeyV1());
Assert.Equal(
"_R4B3fDaVztZshDzof1sXQ90V-JlADF_2WFua87u7qU",
keyAuth);
}
/// <summary>
/// Computes the key authorization string for <paramref name="challenge"/>.
/// </summary>
/// <param name="challenge">The challenge.</param>
/// <param name="key">The key.</param>
/// <returns>The key authorization string.</returns>
public static string ComputeKeyAuthorization(this ChallengeEntity challenge, IAccountKey key)
=> $"{challenge.Token}.{key.Thumbprint()}";