public override UploadResult Upload(Stream stream, string fileName) { bool isPathStyleRequest = Settings.UsePathStyle; if (!isPathStyleRequest && Settings.Bucket.Contains(".")) { isPathStyleRequest = true; } string scheme = URLHelpers.GetPrefix(Settings.Endpoint); string endpoint = URLHelpers.RemovePrefixes(Settings.Endpoint); string host = isPathStyleRequest ? endpoint : $"{Settings.Bucket}.{endpoint}"; string algorithm = "AWS4-HMAC-SHA256"; string credentialDate = DateTime.UtcNow.ToString("yyyyMMdd", CultureInfo.InvariantCulture); string region = GetRegion(); string scope = URLHelpers.CombineURL(credentialDate, region, "s3", "aws4_request"); string credential = URLHelpers.CombineURL(Settings.AccessKeyID, scope); string timeStamp = DateTime.UtcNow.ToString("yyyyMMddTHHmmssZ", CultureInfo.InvariantCulture); string contentType = RequestHelpers.GetMimeType(fileName); string hashedPayload; if (Settings.SignedPayload) { hashedPayload = Helpers.BytesToHex(Helpers.ComputeSHA256(stream)); } else { hashedPayload = "UNSIGNED-PAYLOAD"; } string uploadPath = GetUploadPath(fileName); string resultURL = GenerateURL(uploadPath); OnEarlyURLCopyRequested(resultURL); NameValueCollection headers = new NameValueCollection { ["Host"] = host, ["Content-Length"] = stream.Length.ToString(), ["Content-Type"] = contentType, ["x-amz-date"] = timeStamp, ["x-amz-content-sha256"] = hashedPayload, // If you don't specify, S3 Standard is the default storage class. Amazon S3 supports other storage classes. // Valid Values: STANDARD | REDUCED_REDUNDANCY | STANDARD_IA | ONEZONE_IA | INTELLIGENT_TIERING | GLACIER | DEEP_ARCHIVE // https://docs.aws.amazon.com/AmazonS3/latest/API/API_PutObject.html ["x-amz-storage-class"] = Settings.StorageClass.ToString() }; if (Settings.SetPublicACL) { // The canned ACL to apply to the object. For more information, see Canned ACL. // https://docs.aws.amazon.com/AmazonS3/latest/dev/acl-overview.html#canned-acl headers["x-amz-acl"] = "public-read"; } string canonicalURI = uploadPath; if (isPathStyleRequest) { canonicalURI = URLHelpers.CombineURL(Settings.Bucket, canonicalURI); } canonicalURI = URLHelpers.AddSlash(canonicalURI, SlashType.Prefix); canonicalURI = URLHelpers.URLEncode(canonicalURI, true); string canonicalQueryString = ""; string canonicalHeaders = CreateCanonicalHeaders(headers); string signedHeaders = GetSignedHeaders(headers); string canonicalRequest = "PUT" + "\n" + canonicalURI + "\n" + canonicalQueryString + "\n" + canonicalHeaders + "\n" + signedHeaders + "\n" + hashedPayload; string stringToSign = algorithm + "\n" + timeStamp + "\n" + scope + "\n" + Helpers.BytesToHex(Helpers.ComputeSHA256(canonicalRequest)); byte[] dateKey = Helpers.ComputeHMACSHA256(credentialDate, "AWS4" + Settings.SecretAccessKey); byte[] dateRegionKey = Helpers.ComputeHMACSHA256(region, dateKey); byte[] dateRegionServiceKey = Helpers.ComputeHMACSHA256("s3", dateRegionKey); byte[] signingKey = Helpers.ComputeHMACSHA256("aws4_request", dateRegionServiceKey); string signature = Helpers.BytesToHex(Helpers.ComputeHMACSHA256(stringToSign, signingKey)); headers["Authorization"] = algorithm + " " + "Credential=" + credential + "," + "SignedHeaders=" + signedHeaders + "," + "Signature=" + signature; headers.Remove("Host"); headers.Remove("Content-Type"); string url = URLHelpers.CombineURL(scheme + host, canonicalURI); url = URLHelpers.FixPrefix(url, "https://"); SendRequest(HttpMethod.PUT, url, stream, contentType, null, headers); if (LastResponseInfo != null && LastResponseInfo.IsSuccess) { return(new UploadResult { IsSuccess = true, URL = resultURL }); } Errors.Add("Upload to Amazon S3 failed."); return(null); }