return nil, errKMSNotConfigured
		}
		objectKey, err := crypto.S3.UnsealObjectKey(GlobalKMS, metadata, bucket, object)
		if err != nil {
			return nil, err
		}
		return objectKey[:], nil
	case crypto.S3KMS:
		if GlobalKMS == nil {
			return nil, errKMSNotConfigured
		}
		objectKey, err := crypto.S3KMS.UnsealObjectKey(GlobalKMS, metadata, bucket, object)
		if err != nil {
			return nil, err
		}

			w.Header().Set(xhttp.AmzServerSideEncryptionKmsContext, kmsCtx)
		}
	case crypto.SSEC:
		// Validate the SSE-C Key set in the header.
		if _, err = crypto.SSEC.UnsealObjectKey(r.Header, objInfo.UserDefined, bucket, object); err != nil {
			writeErrorResponse(ctx, w, toAPIError(ctx, err), r.URL)
			return
		}