/// <summary>
/// Signs the final chunk containing trailing headers
/// </summary>
/// <param name="trailingHeaders">Trailing header keys and values</param>
/// <param name="previousSignature">Signature of the previously signed chunk</param>
/// <param name="headerSigningResult">Signing result for the "seed" signature consisting of headers</param>
/// <returns>Signature of the trailing header chunk</returns>
public string SignTrailingHeaderChunk(IDictionary <string, string> trailingHeaders, string previousSignature, AWS4aSigningResult headerSigningResult)
{
var signingConfig = PrepareCRTSigningConfig(AwsSignatureType.HTTP_REQUEST_TRAILING_HEADERS, headerSigningResult);
signingConfig.SignedBodyHeader = AwsSignedBodyHeaderType.NONE;
var headerArray = trailingHeaders.Select(kvp => new HttpHeader(kvp.Key, kvp.Value)).ToArray();
// The previous signature may be padded with '*' up to 144 characters, which is used
// when actually sending a chunk but not when calculating the next chunk's signature.
previousSignature = previousSignature.TrimEnd('*');
var signingResult = AwsSigner.SignTrailingHeaders(headerArray, Encoding.UTF8.GetBytes(previousSignature), signingConfig);
return(Encoding.UTF8.GetString(signingResult.Get().Signature));
}