// characters long, and it must be a sequence of one or more labels
// separated by periods. Each label can contain lowercase ascii
// letters, decimal digits and hyphens, but must not begin or end with
// a hyphen. See:
// http://docs.aws.amazon.com/AmazonS3/latest/dev/BucketRestrictions.html
func IsValidBucketName(bucket string) bool {
	// Special case when bucket is equal to one of the meta buckets.

	objectAPI, _ := validateAdminReq(ctx, w, r, policy.CreatePolicyAdminAction)
	if objectAPI == nil {
		return
	}

	vars := mux.Vars(r)
	policyName := vars["name"]

	// Policy has space characters in begin and end reject such inputs.
	if hasSpaceBE(policyName) {
		writeErrorResponseJSON(ctx, w, errorCodes.ToAPIErr(ErrAdminResourceInvalidArgument), r.URL)
		return
	}

	// Error out if Content-Length is missing.