)

// getCanonicalHeaders generate a list of request headers with their values
func getCanonicalHeaders(signedHeaders http.Header) string {
	var headers []string
	vals := make(http.Header)
	for k, vv := range signedHeaders {
		k = strings.ToLower(k)
		headers = append(headers, k)
		vals[k] = vv
	}
	sort.Strings(headers)

	var buf bytes.Buffer
	for _, k := range headers {
		buf.WriteString(k)
		buf.WriteByte(':')

			// Verify if date headers are set, if not reject the request
			amzDate, errCode := parseAmzDateHeader(r)
			if errCode != ErrNone {
				if ok {
					tc.FuncName = "handler.Auth"
					tc.ResponseRecorder.LogErrBody = true
				}

				// All our internal APIs are sensitive towards Date
				// header, for all requests where Date header is not
				// present we will reject such clients.

	// and don't process the If-Modified-Since header.
	if objInfo.ModTime.IsZero() || objInfo.ModTime.Equal(time.Unix(0, 0)) {
		return false
	}

	// Headers to be set of object content is not going to be written to the client.
	writeHeaders := func() {
		// set common headers
		setCommonHeaders(w)

		// set object-related metadata headers
		w.Header().Set(xhttp.LastModified, objInfo.ModTime.UTC().Format(http.TimeFormat))

	TimeToFirstByte time.Duration
	StartTime       time.Time
	// number of bytes written
	bytesWritten int
	// number of bytes of response headers written
	headerBytesWritten int
	// Internal recording buffer
	headers bytes.Buffer
	body    bytes.Buffer
	// Indicate if headers are written in the log
	headersLogged bool
}

// Hijack - hijacks the underlying connection

	},
	ErrUnsupportedMetadata: {
		Code:           "InvalidArgument",
		Description:    "Your metadata headers are not supported.",
		HTTPStatusCode: http.StatusBadRequest,
	},
	ErrUnsupportedHostHeader: {
		Code:           "InvalidArgument",
		Description:    "Your Host header is malformed.",
		HTTPStatusCode: http.StatusBadRequest,
	},
	ErrObjectTampered: {

		FreeVersion: fi.TierFreeVersion(),
		Tier:        fi.TransitionTier,
	}

	// etag/md5Sum has already been extracted. We need to
	// remove to avoid it from appearing as part of
	// response headers. e.g, X-Minio-* or X-Amz-*.
	// Tags have also been extracted, we remove that as well.
	objInfo.UserDefined = cleanMetadata(fi.Metadata)

	// All the parts per object.
	objInfo.Parts = fi.Parts

	}
	if match.GetPath() != "" {
		conds = append(conds, match.GetPath())
	}
	if match.GetSafeRegex() != nil {
		conds = append(conds, fmt.Sprintf("regex %s", match.GetSafeRegex().Regex))
	}
	// Ignore headers
	return strings.Join(conds, " ")
}

// PrintListenerDump prints the relevant listeners in the config dump to the ConfigWriter stdout

	config.drivercache[tierName] = d
	return nil
}

// Bytes returns msgpack encoded config with format and version headers.
func (config *TierConfigMgr) Bytes() ([]byte, error) {
	config.RLock()
	defer config.RUnlock()
	data := make([]byte, 4, config.Msgsize()+4)

	// Initialize the header.
	binary.LittleEndian.PutUint16(data[0:2], tierConfigFormat)
	binary.LittleEndian.PutUint16(data[2:4], tierConfigVersion)

	}
	if v, ok := header[xhttp.MinIOSourceProxyRequest]; ok {
		opts.ProxyHeaderSet = true
		opts.ProxyRequest = strings.Join(v, "") == "true"
	}
	if _, ok := header[xhttp.MinIOSourceReplicationRequest]; ok {
		opts.ReplicationRequest = true
	}
	opts.Speedtest = header.Get(globalObjectPerfUserMetadata) != ""
	return
}

// get ObjectOptions for GET calls from encryption headers

	if r.NotificationCfg.Endpoint == "" {
		return nil
	}

	ctx, cancel := context.WithTimeout(ctx, 10*time.Second)
	defer cancel()

	req, err := http.NewRequestWithContext(ctx, http.MethodPost, r.NotificationCfg.Endpoint, body)
	if err != nil {
		return err
	}

	if r.NotificationCfg.Token != "" {
		req.Header.Set("Authorization", r.NotificationCfg.Token)