package ssh

import "regexp"

var clientVersionVerifier = regexp.MustCompile(`^[a-zA-Z0-9\.\-\_]+\x{20}?[a-zA-Z0-9\.\-\_]+?$`)

// isValidClientVersion returns true if provided SSH client version string is compliant with RFC-4253.
func isValidClientVersion(ver string) bool {
	return clientVersionVerifier.MatchString(ver)
}