// It returns the client provided key on success.
func ParseSSECustomerRequest(r *http.Request) (key []byte, err error) {
	return ParseSSECustomerHeader(r.Header)
}

// ParseSSECustomerHeader parses the SSE-C header fields and returns
// the client provided key on success.
func ParseSSECustomerHeader(header http.Header) (key []byte, err error) {
	if crypto.S3.IsRequested(header) && crypto.SSEC.IsRequested(header) {

		var (
			reader io.Reader
			keyID  string
			key    []byte
			kmsCtx kms.Context
		)
		kind, _ := crypto.IsRequested(formValues)
		switch kind {
		case crypto.SSEC:
			key, err = ParseSSECustomerHeader(formValues)
			if err != nil {
				writeErrorResponse(ctx, w, toAPIError(ctx, err), r.URL)
				return
			}
		case crypto.S3KMS:
			keyID, kmsCtx, err = crypto.S3KMS.ParseHTTP(formValues)