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mirror of https://github.com/namecoin/ncdns synced 2024-11-16 00:13:01 +00:00
ncdns/util/util.go
2017-11-04 08:01:40 +00:00

270 lines
9.0 KiB
Go

package util
import "strings"
import "gopkg.in/hlandau/madns.v1/merr"
import "fmt"
import "regexp"
import "net/mail"
// Split a domain name a.b.c.d.e into parts e (the head) and a.b.c.d (the rest).
func SplitDomainHead(name string) (head, rest string) {
if len(name) > 0 && name[len(name)-1] == '.' {
name = name[0 : len(name)-1]
}
parts := strings.Split(name, ".")
head = parts[len(parts)-1]
if len(parts) >= 2 {
rest = strings.Join(parts[0:len(parts)-1], ".")
}
return
}
// Split a domain name a.b.c.d.e into parts a (the tail) and b.c.d.e (the rest).
func SplitDomainTail(name string) (tail, rest string) {
s := strings.SplitN(name, ".", 2)
if len(s) == 1 {
return s[0], ""
}
return s[0], s[1]
}
// For domains of the form "Y1.Y2...Yn.ANCHOR.X1.X2...Xn.", returns the following values:
//
// basename is the name appearing directly beneath the anchor (Yn).
//
// subname contains any additional labels appearing beneath the anchor (Y1 through Y(n-1)),
// separated by dots.
//
// rootname contains ANCHOR through Xn inclusive, separated by dots.
//
// If no label corresponds to ANCHOR, an error is returned.
// If ANCHOR is the first label, basename is an empty string.
//
// Examples, where anchor="bit":
// "a.b.c.d." -> merr.ErrNotInZone
// "a.b.c.d.bit." -> subname="a.b.c", basename="d", rootname="bit"
// "d.bit." -> subname="", basename="d", rootname="bit"
// "bit." -> subname="", basename="", rootname="bit"
// "bit.x.y.z." -> subname="", basename="", rootname="bit.x.y.z"
// "d.bit.x.y.z." -> subname="", basename="d", rootname="bit.x.y.z"
// "c.d.bit.x.y.z." -> subname="c", basename="d", rootname="bit.x.y.z"
// "a.b.c.d.bit.x.y.z." -> subname="a.b.c", basename="d", rootname="bit.x.y.z"
func SplitDomainByFloatingAnchor(qname, anchor string) (subname, basename, rootname string, err error) {
qname = strings.TrimRight(qname, ".")
parts := strings.Split(qname, ".")
if len(parts) < 2 {
if parts[0] != anchor {
err = merr.ErrNotInZone
return
}
rootname = parts[0]
return
}
for i := len(parts) - 1; i >= 0; i-- {
v := parts[i]
// scanning for rootname
if v == anchor {
if i == 0 {
// i is alreay zero, so we have something like bit.x.y.z.
rootname = qname
return
}
rootname = strings.Join(parts[i:], ".")
basename = parts[i-1]
subname = strings.Join(parts[0:i-1], ".")
return
}
}
err = merr.ErrNotInZone
return
}
// Convert a domain name basename (e.g. "example") to a Namecoin domain name
// key name ("d/example").
func BasenameToNamecoinKey(basename string) (string, error) {
if !ValidateDomainLabel(basename) {
return "", fmt.Errorf("invalid domain name")
}
return basenameToNamecoinKey(basename), nil
}
func basenameToNamecoinKey(basename string) string {
return "d/" + basename
}
// Convert a Namecoin domain name key name (e.g. "d/example") to a domain name
// basename ("example").
func NamecoinKeyToBasename(key string) (string, error) {
if !strings.HasPrefix(key, "d/") {
return "", fmt.Errorf("not a valid domain name key")
}
key = key[2:]
if !ValidateDomainLabel(key) {
return "", fmt.Errorf("not a valid domain name key")
}
return key, nil
}
// An owner name is any technically valid DNS name. RFC 2181 permits binary
// data in DNS labels (!), but this is ridiculous. The conventions which appear
// to be enforced by web browsers are used.
const sre_ownerLabel = `([a-z0-9_]|[a-z0-9_][a-z0-9_-]{0,61}[a-z0-9_])`
const sre_ownerName = `(` + sre_ownerLabel + `\.)*` + sre_ownerLabel + `\.?` // must check length
const sre_relOwnerName = `(|@|(` + sre_ownerLabel + `\.)*` + sre_ownerLabel + `(\.@?)?)` // must check length
var re_ownerLabel = regexp.MustCompilePOSIX(`^` + sre_ownerLabel + `$`)
var re_ownerName = regexp.MustCompilePOSIX(`^` + sre_ownerName + `$`)
var re_relOwnerName = regexp.MustCompilePOSIX(`^` + sre_relOwnerName + `$`)
const sre_domainLabel = `(xn--)?([a-z0-9]+-)*[a-z0-9]+` // must check length
const sre_domainName = `(` + sre_domainLabel + `\.)*` + sre_domainLabel + `\.?` // must check length
const sre_relDomainName = `(|@|(` + sre_domainLabel + `\.)*` + sre_domainLabel + `(\.@?)?)` // must check length
var re_domainLabel = regexp.MustCompilePOSIX(`^` + sre_domainLabel + `$`)
var re_domainName = regexp.MustCompilePOSIX(`^` + sre_domainName + `$`)
var re_relDomainName = regexp.MustCompilePOSIX(`^` + sre_relDomainName + `$`)
const sre_hostLabel = `([a-z0-9]|[a-z0-9][a-z0-9-]*[a-z0-9])` // must check length
const sre_hostName = sre_hostLabel + `(\.` + sre_hostLabel + `)*\.?` // must check length
const sre_relHostName = `(|@|(` + sre_hostLabel + `\.)*` + sre_hostLabel + `(\.@?)?)` // must check length
var re_hostLabel = regexp.MustCompilePOSIX(`^` + sre_hostLabel + `$`)
var re_hostName = regexp.MustCompilePOSIX(`^` + sre_hostName + `$`)
var re_relHostName = regexp.MustCompilePOSIX(`^` + sre_relHostName + `$`)
func ValidateLabelLength(label string) bool {
return len(label) <= 63
}
func ValidateNameLength(name string) bool {
return len(name) <= 255 || (name[len(name)-1] == '.' && len(name) <= 256)
}
func ValidateOwnerLabel(label string) bool {
return ValidateLabelLength(label) && re_ownerLabel.MatchString(label)
}
func ValidateServiceName(label string) bool {
return len(label) <= 62 && ValidateOwnerLabel(label)
}
func ValidateOwnerName(name string) bool {
return ValidateNameLength(name) && re_ownerName.MatchString(name)
}
func ValidateRelOwnerName(name string) bool {
return ValidateNameLength(name) && re_relOwnerName.MatchString(name)
}
func ValidateDomainLabel(label string) bool {
return ValidateLabelLength(label) && re_domainLabel.MatchString(label)
}
func ValidateDomainName(name string) bool {
return ValidateNameLength(name) && re_domainName.MatchString(name)
}
func ValidateRelDomainName(name string) bool {
return ValidateNameLength(name) && re_relDomainName.MatchString(name)
}
func ValidateHostLabel(label string) bool {
return ValidateLabelLength(label) && re_hostLabel.MatchString(label)
}
func ValidateHostName(name string) bool {
return ValidateNameLength(name) && re_hostName.MatchString(name)
}
func ValidateRelHostName(name string) bool {
return ValidateNameLength(name) && re_relHostName.MatchString(name)
}
/*
var re_ownerName = regexp.MustCompilePOSIX(`^([a-z0-9_][a-z0-9_-]{0,62}\.)*[a-z0-9_][a-z0-9_-]{0,62}\.?$`)
var re_ownerLabel = regexp.MustCompilePOSIX(`^([a-z0-9_]{1,2}|[a-z0-9_][a-z0-9_-]{0,61}[a-z0-9_])$`)
// A domain name is an owner name complying with the standard rules applied to
// domain names: No consecutive hyphens except as allowed by IDN, no underscores.
var re_domainName = regexp.MustCompilePOSIX(`^(([a-z0-9]+-)*[a-z0-9]+\.)*$`)
// This is used to validate NS records, targets in SRV records, etc. In these cases
// an IP address is not allowed. Therefore this regex must exclude all-numeric domain names.
// This is done by requiring the final part to start with an alphabetic character.
var re_hostName = regexp.MustCompilePOSIX(`^(([a-z0-9_][a-z0-9_-]{0,62}\.)*[a-z_][a-z0-9_-]{0,62}\.?|\.)$`)
var re_label = regexp.MustCompilePOSIX(`^[a-z_][a-z0-9_-]*$`)
var re_serviceName = regexp.MustCompilePOSIX(`^[a-z_][a-z0-9_-]*$`)
var re_domainNameLabel = regexp.MustCompilePOSIX(`^(xn--)?[a-z0-9]+(-[a-z0-9]+)*$`)
var re_ownerName = regexp.MustCompilePOSIX(`^(|@|([a-z0-9_-]{1,63}\.)*[a-z0-9_-]{1,63}(\.@?)?)$`)
func ValidateHostName(name string) bool {
name = dns.Fqdn(name)
return len(name) <= 255 && re_hostName.MatchString(name)
}
func ValidateLabel(name string) bool {
return len(name) <= 63 && re_label.MatchString(name)
}
func ValidateServiceName(name string) bool {
return len(name) < 63 && re_serviceName.MatchString(name)
}
func ValidateDomainNameLabel(name string) bool {
return len(name) <= 63 && re_domainNameLabel.MatchString(name)
}
func ValidateOwnerName(name string) bool {
return len(name) <= 255 && re_ownerName.MatchString(name)
}*/
func ValidateEmail(email string) bool {
addr, err := mail.ParseAddress(email)
if addr == nil || err != nil {
return false
}
return addr.Name == ""
}
// Takes a name in the form "d/example" or "example.bit" and converts it to the
// bareword "example". Returns an error if the input is in neither form.
func ParseFuzzyDomainName(name string) (string, error) {
if strings.HasPrefix(name, "d/") {
return NamecoinKeyToBasename(name)
}
if len(name) > 0 && name[len(name)-1] == '.' {
name = name[0 : len(name)-1]
}
if strings.HasSuffix(name, ".bit") {
name = name[0 : len(name)-4]
if !ValidateDomainLabel(name) {
return "", fmt.Errorf("invalid domain name")
}
return name, nil
}
return "", fmt.Errorf("invalid domain name")
}
func ParseFuzzyDomainNameNC(name string) (bareName string, namecoinKey string, err error) {
name, err = ParseFuzzyDomainName(name)
if err != nil {
return "", "", err
}
return name, basenameToNamecoinKey(name), nil
}
// © 2014 Hugo Landau <hlandau@devever.net> GPLv3 or later