func (ssec) IsEncrypted(metadata map[string]string) bool {
	if _, ok := metadata[MetaSealedKeySSEC]; ok {
		return true
	}
	return false
}

// ParseHTTP parses the SSE-C headers and returns the SSE-C client key
// on success. SSE-C copy headers are ignored.
func (ssec) ParseHTTP(h http.Header) (key [32]byte, err error) {
	if h.Get(xhttp.AmzServerSideEncryptionCustomerAlgorithm) != xhttp.AmzEncryptionAES {

		return true
	}
	if _, ok := h[xhttp.AmzServerSideEncryptionCopyCustomerKeyMD5]; ok {
		return true
	}
	return false
}

// ParseHTTP parses the SSE-C copy headers and returns the SSE-C client key
// on success. Regular SSE-C headers are ignored.
func (ssecCopy) ParseHTTP(h http.Header) (key [32]byte, err error) {
	if h.Get(xhttp.AmzServerSideEncryptionCopyCustomerAlgorithm) != xhttp.AmzEncryptionAES {

	return ok && !strings.EqualFold(h.Get(xhttp.AmzServerSideEncryption), xhttp.AmzEncryptionKMS)
}

// ParseHTTP parses the SSE-S3 related HTTP headers and checks
// whether they contain valid values.
func (sses3) ParseHTTP(h http.Header) error {
	if h.Get(xhttp.AmzServerSideEncryption) != xhttp.AmzEncryptionAES {
		return ErrInvalidEncryptionMethod
	}
	return nil
}

		return strings.ToUpper(h.Get(xhttp.AmzServerSideEncryption)) != xhttp.AmzEncryptionAES
	}
	return false
}

// ParseHTTP parses the SSE-KMS headers and returns the SSE-KMS key ID
// and the KMS context on success.
func (ssekms) ParseHTTP(h http.Header) (string, kms.Context, error) {
	if h == nil {
		return "", nil, ErrInvalidEncryptionMethod
	}

	algorithm := h.Get(xhttp.AmzServerSideEncryption)

// and returns the decrypted object key.
func (sse ssecCopy) UnsealObjectKey(h http.Header, metadata map[string]string, bucket, object string) (key ObjectKey, err error) {
	clientKey, err := sse.ParseHTTP(h)
	if err != nil {
		return key, err
	}
	return unsealObjectKey(clientKey[:], metadata, bucket, object)
}

// unsealObjectKey decrypts and returns the sealed object key