Amazon.S3.AmazonS3Client.GetPreSignedURLInternal C# (CSharp) Метод

        internal string GetPreSignedURLInternal(GetPreSignedUrlRequest request, bool useSigV2Fallback = true)
        {
            if (Credentials == null)
                throw new AmazonS3Exception("Credentials must be specified, cannot call method anonymously");

            if (request == null)
                throw new ArgumentNullException("request", "The PreSignedUrlRequest specified is null!");

            if (!request.IsSetExpires())
                throw new InvalidOperationException("The Expires specified is null!");

            var aws4Signing = AWSConfigsS3.UseSignatureVersion4;
            var region = AWS4Signer.DetermineSigningRegion(Config, "s3", alternateEndpoint: null, request: null);
            if (aws4Signing && string.IsNullOrEmpty(region))
                throw new InvalidOperationException("To use AWS4 signing, a region must be specified in the client configuration using the AuthenticationRegion or Region properties, or be determinable from the service URL.");

            RegionEndpoint endpoint = RegionEndpoint.GetBySystemName(region);
            if (endpoint.GetEndpointForService("s3").SignatureVersionOverride == "4" || endpoint.GetEndpointForService("s3").SignatureVersionOverride == null)
                aws4Signing = true;

            var fallbackToSigV2 = useSigV2Fallback && !AWSConfigsS3.UseSigV4SetExplicitly;
            if (endpoint == RegionEndpoint.USEast1 && fallbackToSigV2)
                aws4Signing = false;

            // If the expiration is longer than SigV4 will allow then automatically use SigV2 instead.
            // But only if the region we're signing for allows SigV2.
            if (aws4Signing)
            {
                var secondsUntilExpiration = GetSecondsUntilExpiration(request, aws4Signing);

                if (secondsUntilExpiration > AWS4PreSignedUrlSigner.MaxAWS4PreSignedUrlExpiry &&
                    endpoint.GetEndpointForService("s3").SignatureVersionOverride == "2")
                {
                    aws4Signing = false;
                }
            }

            var immutableCredentials = Credentials.GetCredentials();
            var irequest = Marshall(request, immutableCredentials.AccessKey, immutableCredentials.Token, aws4Signing);

            irequest.Endpoint = EndpointResolver.DetermineEndpoint(this.Config, irequest);

            var context = new Amazon.Runtime.Internal.ExecutionContext(new Amazon.Runtime.Internal.RequestContext(true) { Request = irequest, ClientConfig = this.Config }, null);
            AmazonS3PostMarshallHandler.ProcessRequestHandlers(context);

            var metrics = new RequestMetrics();

            string authorization;
            if (aws4Signing)
            {
                var aws4Signer = new AWS4PreSignedUrlSigner();
                var signingResult = aws4Signer.SignRequest(irequest,
                                                           this.Config,
                                                           metrics,
                                                           immutableCredentials.AccessKey,
                                                           immutableCredentials.SecretKey);
                authorization = "&" + signingResult.ForQueryParameters;
            }
            else
            {
                S3Signer.SignRequest(irequest, metrics, immutableCredentials.AccessKey, immutableCredentials.SecretKey);
                authorization = irequest.Headers[HeaderKeys.AuthorizationHeader];
                authorization = authorization.Substring(authorization.IndexOf(":", StringComparison.Ordinal) + 1);
                authorization = "&Signature=" + AmazonS3Util.UrlEncode(authorization, false);
            }

            Uri url = AmazonServiceClient.ComposeUrl(irequest);
            string result = url.AbsoluteUri + authorization;

            Protocol protocol = DetermineProtocol();
            if (request.Protocol != protocol)
            {
                switch (protocol)
                {
                    case Protocol.HTTP:
                        result = result.Replace("http://", "https://");
                        break;
                    case Protocol.HTTPS:
                        result = result.Replace("https://", "http://");
                        break;
                }
            }
            return result;
        }