/// <summary>
/// Calculates the signature for the specified request using the Asymmetric SigV4 signing protocol
/// </summary>
/// <param name="request">
/// The request to compute the signature for. Additional headers mandated by the
/// SigV4a protocol will be added to the request before signing.
/// </param>
/// <param name="clientConfig">
/// Client configuration data encompassing the service call (notably authentication
/// region, endpoint and service name).
/// </param>
/// <param name="metrics">Metrics for the request</param>
/// <param name="credentials">The AWS credentials for the account making the service call</param>
/// <returns>AWS4aSigningResult for the given request</returns>
public AWS4aSigningResult SignRequest(IRequest request,
IClientConfig clientConfig,
RequestMetrics metrics,
ImmutableCredentials credentials)
{
var signedAt = AWS4Signer.InitializeHeaders(request.Headers, request.Endpoint);
var serviceSigningName = !string.IsNullOrEmpty(request.OverrideSigningServiceName) ? request.OverrideSigningServiceName : AWS4Signer.DetermineService(clientConfig);
var regionSet = AWS4Signer.DetermineSigningRegion(clientConfig, clientConfig.RegionEndpointServiceName, request.AlternateEndpoint, request);
request.DeterminedSigningRegion = regionSet;
AWS4Signer.SetXAmzTrailerHeader(request.Headers, request.TrailingHeaders);
var signingConfig = PrepareCRTSigningConfig(AwsSignatureType.HTTP_REQUEST_VIA_HEADERS, regionSet, serviceSigningName, signedAt, credentials);
// If the request should use a fixed x-amz-content-sha256 header value, determine the appropriate one
var fixedBodyHash = request.TrailingHeaders?.Count > 0
? AWS4Signer.V4aStreamingBodySha256WithTrailer
: AWS4Signer.V4aStreamingBodySha256;
signingConfig.SignedBodyValue = AWS4Signer.SetRequestBodyHash(request, SignPayload, fixedBodyHash, ChunkedUploadWrapperStream.V4A_SIGNATURE_LENGTH);
var crtRequest = CrtHttpRequestConverter.ConvertToCrtRequest(request);
var signingResult = AwsSigner.SignHttpRequest(crtRequest, signingConfig);
var authorizationValue = Encoding.Default.GetString(signingResult.Get().Signature);
var signedCrtRequest = signingResult.Get().SignedRequest;
CrtHttpRequestConverter.CopyHeadersFromCrtRequest(request, signedCrtRequest);
var dateStamp = AWS4Signer.FormatDateTime(signedAt, AWSSDKUtils.ISO8601BasicDateFormat);
var scope = string.Format(CultureInfo.InvariantCulture, "{0}/{1}/{2}", dateStamp, serviceSigningName, AWS4Signer.Terminator);
AWS4aSigningResult result = new AWS4aSigningResult(
credentials.AccessKey,
signedAt,
CrtHttpRequestConverter.ExtractSignedHeaders(signedCrtRequest),
scope,
regionSet,
authorizationValue,
serviceSigningName,
"",
credentials);
return(result);
}