"X-Amz-Date":           now.AddDate(0, 0, -2).Format(iso8601Format),
				"X-Amz-Content-Sha256": payloadSHA256,
			},
			region:   region,
			expected: ErrExpiredPresignRequest,
		},
		// (5) Should error if the signature is incorrect.
		{
			queryParams: map[string]string{
				"X-Amz-Algorithm":      signV4Algorithm,
				"X-Amz-Date":           now.Format(iso8601Format),
				"X-Amz-Expires":        "60",

	"github.com/minio/minio/internal/hash/sha256"
	xhttp "github.com/minio/minio/internal/http"
)

// AWS Signature Version '4' constants.
const (
	signV4Algorithm = "AWS4-HMAC-SHA256"
	iso8601Format   = "20060102T150405Z"
	yyyymmdd        = "20060102"
)

type serviceType string

const (
	serviceS3  serviceType = "s3"
	serviceSTS serviceType = "sts"
)

			}
			// validating presign date field.
			if testCase.expectedPreSignValues.Date.UTC().Format(iso8601Format) != parsedPreSign.Date.UTC().Format(iso8601Format) {
				t.Errorf("Test %d: Expected date to be %v, but got %v", i+1, testCase.expectedPreSignValues.Date.UTC().Format(iso8601Format), parsedPreSign.Date.UTC().Format(iso8601Format))
			}
		}

	}

		ETag:         "\"" + etag + "\"",
		LastModified: amztime.ISO8601Format(lastModified.UTC()),
	}
}

// generates CopyObjectPartResponse from etag and lastModified time.
func generateCopyObjectPartResponse(etag string, lastModified time.Time) CopyObjectPartResponse {
	return CopyObjectPartResponse{
		ETag:         "\"" + etag + "\"",
		LastModified: amztime.ISO8601Format(lastModified.UTC()),
	}
}

	hashedChunk := hex.EncodeToString(cr.chunkSHA256Writer.Sum(nil))

	// Calculate string to sign.
	alg := signV4ChunkedAlgorithm + "\n"
	stringToSign := alg +
		cr.seedDate.Format(iso8601Format) + "\n" +
		getScope(cr.seedDate, cr.region) + "\n" +
		cr.seedSignature + "\n" +
		emptySHA256 + "\n" +
		hashedChunk

	// Get hmac signing key.

	signedHeaders = append(signedHeaders, "expect")
	// expected header values.
	expectedHost := "play.min.io:9000"
	expectedContentSha256 := "1234abcd"
	expectedTime := UTCNow().Format(iso8601Format)
	expectedTransferEncoding := "gzip"
	expectedExpect := "100-continue"

	r, err := http.NewRequest(http.MethodGet, "http://play.min.io:9000", nil)
	if err != nil {

// empty string otherwise
func (rDate RetentionDate) MarshalXML(e *xml.Encoder, startElement xml.StartElement) error {
	if rDate.IsZero() {
		return nil
	}
	return e.EncodeElement(amztime.ISO8601Format(rDate.Time), startElement)
}

// ObjectRetention specified in
// https://docs.aws.amazon.com/AmazonS3/latest/API/API_PutObjectRetention.html
type ObjectRetention struct {

	if s3Err == ErrNone && retentionMode.Valid() {
		metadata[strings.ToLower(xhttp.AmzObjectLockMode)] = string(retentionMode)
		metadata[strings.ToLower(xhttp.AmzObjectLockRetainUntilDate)] = amztime.ISO8601Format(retentionDate.UTC())
	}
	if s3Err == ErrNone && legalHold.Status.Valid() {
		metadata[strings.ToLower(xhttp.AmzObjectLockLegalHold)] = string(legalHold.Status)
	}
	if s3Err != ErrNone {