func newUnsignedV4ChunkedReader(req *http.Request, trailer bool, signature bool) (io.ReadCloser, APIErrorCode) {
	if signature {
		if errCode := doesSignatureMatch(unsignedPayloadTrailer, req, globalSite.Region(), serviceS3); errCode != ErrNone {
			return nil, errCode
		}
	}
	if trailer {
		// Discard anything unsigned.
		req.Trailer = make(http.Header)

const unsignedPayload = "UNSIGNED-PAYLOAD"

// http Header "x-amz-content-sha256" == "STREAMING-UNSIGNED-PAYLOAD-TRAILER" indicates that the
// client did not calculate sha256 of the payload and there is a trailer.
const unsignedPayloadTrailer = "STREAMING-UNSIGNED-PAYLOAD-TRAILER"

// skipContentSha256Cksum returns true if caller needs to skip
// payload checksum, false if not.
func skipContentSha256Cksum(r *http.Request) bool {
	var (
		v  []string

}

// Verify if the request has AWS Streaming Signature Version '4', with unsigned content and trailer.
func isRequestUnsignedTrailerV4(r *http.Request) bool {
	return r.Header.Get(xhttp.AmzContentSha256) == unsignedPayloadTrailer &&
		r.Method == http.MethodPut
}

// Authorization type.
//
//go:generate stringer -type=authType -trimprefix=authType $GOFILE
type authType int

// List of all supported auth types.

		"X-Amz-Decoded-Content-Length": []string{"8"},
		"Content-Encoding":             []string{"aws-chunked"},
		"X-Amz-Trailer":                []string{"x-amz-checksum-crc32"},
		"x-amz-content-sha256":         []string{unsignedPayloadTrailer},
	}

	for k, v := range maliciousHeaders {
		req.Header.Set(k, v[0])
	}

	// execute the request.
	response, err = s.client.Do(req)
	c.Assert(err, nil)