Remove idn/ (#584)

Superseded by x/net/idna. It was useful, but not anymore; remove
entire directory.

Fixes #518
This commit is contained in:
Miek Gieben 2017-11-25 08:18:44 +00:00 committed by GitHub
parent cdb76b64a3
commit e776a21550
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4 changed files with 0 additions and 2850 deletions

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@ -1,18 +0,0 @@
package idn_test
import (
"fmt"
"github.com/miekg/dns/idn"
)
func ExampleToPunycode() {
name := "インターネット.テスト"
fmt.Printf("%s -> %s", name, idn.ToPunycode(name))
// Output: インターネット.テスト -> xn--eckucmux0ukc.xn--zckzah
}
func ExampleFromPunycode() {
name := "xn--mgbaja8a1hpac.xn--mgbachtv"
fmt.Printf("%s -> %s", name, idn.FromPunycode(name))
// Output: xn--mgbaja8a1hpac.xn--mgbachtv -> الانترنت.اختبار
}

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@ -1,370 +0,0 @@
// Package idn implements encoding from and to punycode as speficied by RFC 3492.
package idn
import (
"bytes"
"strings"
"unicode"
"unicode/utf8"
"github.com/miekg/dns"
)
// Implementation idea from RFC itself and from from IDNA::Punycode created by
// Tatsuhiko Miyagawa <miyagawa@bulknews.net> and released under Perl Artistic
// License in 2002.
const (
_MIN rune = 1
_MAX rune = 26
_SKEW rune = 38
_BASE rune = 36
_BIAS rune = 72
_N rune = 128
_DAMP rune = 700
_DELIMITER = '-'
_PREFIX = "xn--"
)
// ToPunycode converts unicode domain names to DNS-appropriate punycode names.
// This function will return an empty string result for domain names with
// invalid unicode strings. This function expects domain names in lowercase.
func ToPunycode(s string) string {
// Early check to see if encoding is needed.
// This will prevent making heap allocations when not needed.
if !needToPunycode(s) {
return s
}
tokens := dns.SplitDomainName(s)
switch {
case s == "":
return ""
case tokens == nil: // s == .
return "."
case s[len(s)-1] == '.':
tokens = append(tokens, "")
}
for i := range tokens {
t := encode([]byte(tokens[i]))
if t == nil {
return ""
}
tokens[i] = string(t)
}
return strings.Join(tokens, ".")
}
// FromPunycode returns unicode domain name from provided punycode string.
// This function expects punycode strings in lowercase.
func FromPunycode(s string) string {
// Early check to see if decoding is needed.
// This will prevent making heap allocations when not needed.
if !needFromPunycode(s) {
return s
}
tokens := dns.SplitDomainName(s)
switch {
case s == "":
return ""
case tokens == nil: // s == .
return "."
case s[len(s)-1] == '.':
tokens = append(tokens, "")
}
for i := range tokens {
tokens[i] = string(decode([]byte(tokens[i])))
}
return strings.Join(tokens, ".")
}
// digitval converts single byte into meaningful value that's used to calculate decoded unicode character.
const errdigit = 0xffff
func digitval(code rune) rune {
switch {
case code >= 'A' && code <= 'Z':
return code - 'A'
case code >= 'a' && code <= 'z':
return code - 'a'
case code >= '0' && code <= '9':
return code - '0' + 26
}
return errdigit
}
// lettercode finds BASE36 byte (a-z0-9) based on calculated number.
func lettercode(digit rune) rune {
switch {
case digit >= 0 && digit <= 25:
return digit + 'a'
case digit >= 26 && digit <= 36:
return digit - 26 + '0'
}
panic("dns: not reached")
}
// adapt calculates next bias to be used for next iteration delta.
func adapt(delta rune, numpoints int, firsttime bool) rune {
if firsttime {
delta /= _DAMP
} else {
delta /= 2
}
var k rune
for delta = delta + delta/rune(numpoints); delta > (_BASE-_MIN)*_MAX/2; k += _BASE {
delta /= _BASE - _MIN
}
return k + ((_BASE-_MIN+1)*delta)/(delta+_SKEW)
}
// next finds minimal rune (one with lowest codepoint value) that should be equal or above boundary.
func next(b []rune, boundary rune) rune {
if len(b) == 0 {
panic("dns: invalid set of runes to determine next one")
}
m := b[0]
for _, x := range b[1:] {
if x >= boundary && (m < boundary || x < m) {
m = x
}
}
return m
}
// preprune converts unicode rune to lower case. At this time it's not
// supporting all things described in RFCs.
func preprune(r rune) rune {
if unicode.IsUpper(r) {
r = unicode.ToLower(r)
}
return r
}
// tfunc is a function that helps calculate each character weight.
func tfunc(k, bias rune) rune {
switch {
case k <= bias:
return _MIN
case k >= bias+_MAX:
return _MAX
}
return k - bias
}
// needToPunycode returns true for strings that require punycode encoding
// (contain unicode characters).
func needToPunycode(s string) bool {
// This function is very similar to bytes.Runes. We don't use bytes.Runes
// because it makes a heap allocation that's not needed here.
for i := 0; len(s) > 0; i++ {
r, l := utf8.DecodeRuneInString(s)
if r > 0x7f {
return true
}
s = s[l:]
}
return false
}
// needFromPunycode returns true for strings that require punycode decoding.
func needFromPunycode(s string) bool {
if s == "." {
return false
}
off := 0
end := false
pl := len(_PREFIX)
sl := len(s)
// If s starts with _PREFIX.
if sl > pl && s[off:off+pl] == _PREFIX {
return true
}
for {
// Find the part after the next ".".
off, end = dns.NextLabel(s, off)
if end {
return false
}
// If this parts starts with _PREFIX.
if sl-off > pl && s[off:off+pl] == _PREFIX {
return true
}
}
}
// encode transforms Unicode input bytes (that represent DNS label) into
// punycode bytestream. This function would return nil if there's an invalid
// character in the label.
func encode(input []byte) []byte {
n, bias := _N, _BIAS
b := bytes.Runes(input)
for i := range b {
if !isValidRune(b[i]) {
return nil
}
b[i] = preprune(b[i])
}
basic := make([]byte, 0, len(b))
for _, ltr := range b {
if ltr <= 0x7f {
basic = append(basic, byte(ltr))
}
}
basiclen := len(basic)
fulllen := len(b)
if basiclen == fulllen {
return basic
}
var out bytes.Buffer
out.WriteString(_PREFIX)
if basiclen > 0 {
out.Write(basic)
out.WriteByte(_DELIMITER)
}
var (
ltr, nextltr rune
delta, q rune // delta calculation (see rfc)
t, k, cp rune // weight and codepoint calculation
)
for h := basiclen; h < fulllen; n, delta = n+1, delta+1 {
nextltr = next(b, n)
delta, n = delta+(nextltr-n)*rune(h+1), nextltr
for _, ltr = range b {
if ltr < n {
delta++
}
if ltr == n {
q = delta
for k = _BASE; ; k += _BASE {
t = tfunc(k, bias)
if q < t {
break
}
cp = t + ((q - t) % (_BASE - t))
out.WriteRune(lettercode(cp))
q = (q - t) / (_BASE - t)
}
out.WriteRune(lettercode(q))
bias = adapt(delta, h+1, h == basiclen)
h, delta = h+1, 0
}
}
}
return out.Bytes()
}
// decode transforms punycode input bytes (that represent DNS label) into Unicode bytestream.
func decode(b []byte) []byte {
src := b // b would move and we need to keep it
n, bias := _N, _BIAS
if !bytes.HasPrefix(b, []byte(_PREFIX)) {
return b
}
out := make([]rune, 0, len(b))
b = b[len(_PREFIX):]
for pos := len(b) - 1; pos >= 0; pos-- {
// only last delimiter is our interest
if b[pos] == _DELIMITER {
out = append(out, bytes.Runes(b[:pos])...)
b = b[pos+1:] // trim source string
break
}
}
if len(b) == 0 {
return src
}
var (
i, oldi, w rune
ch byte
t, digit rune
ln int
)
for i = 0; len(b) > 0; i++ {
oldi, w = i, 1
for k := _BASE; len(b) > 0; k += _BASE {
ch, b = b[0], b[1:]
digit = digitval(rune(ch))
if digit == errdigit {
return src
}
i += digit * w
if i < 0 {
// safety check for rune overflow
return src
}
t = tfunc(k, bias)
if digit < t {
break
}
w *= _BASE - t
}
ln = len(out) + 1
bias = adapt(i-oldi, ln, oldi == 0)
n += i / rune(ln)
i = i % rune(ln)
// insert
out = append(out, 0)
copy(out[i+1:], out[i:])
out[i] = n
}
var ret bytes.Buffer
for _, r := range out {
ret.WriteRune(r)
}
return ret.Bytes()
}
// isValidRune checks if the character is valid. We will look for the
// character property in the code points list. For now we aren't checking special
// rules in case of contextual property
func isValidRune(r rune) bool {
return findProperty(r) == propertyPVALID
}
// findProperty will try to check the code point property of the given
// character. It will use a binary search algorithm as we have a slice of
// ordered ranges (average case performance O(log n))
func findProperty(r rune) property {
imin, imax := 0, len(codePoints)
for imax >= imin {
imid := (imin + imax) / 2
codePoint := codePoints[imid]
if (codePoint.start == r && codePoint.end == 0) || (codePoint.start <= r && codePoint.end >= r) {
return codePoint.state
}
if (codePoint.end > 0 && codePoint.end < r) || (codePoint.end == 0 && codePoint.start < r) {
imin = imid + 1
} else {
imax = imid - 1
}
}
return propertyUnknown
}

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@ -1,116 +0,0 @@
package idn
import (
"strings"
"testing"
)
var testcases = [][2]string{
{"", ""},
{"a", "a"},
{"a-b", "a-b"},
{"a-b-c", "a-b-c"},
{"abc", "abc"},
{"я", "xn--41a"},
{"zя", "xn--z-0ub"},
{"яZ", "xn--z-zub"},
{"а-я", "xn----7sb8g"},
{"إختبار", "xn--kgbechtv"},
{"آزمایشی", "xn--hgbk6aj7f53bba"},
{"测试", "xn--0zwm56d"},
{"測試", "xn--g6w251d"},
{"испытание", "xn--80akhbyknj4f"},
{"परीक्षा", "xn--11b5bs3a9aj6g"},
{"δοκιμή", "xn--jxalpdlp"},
{"테스트", "xn--9t4b11yi5a"},
{"טעסט", "xn--deba0ad"},
{"テスト", "xn--zckzah"},
{"பரிட்சை", "xn--hlcj6aya9esc7a"},
{"mamão-com-açúcar", "xn--mamo-com-acar-yeb1e6q"},
{"σ", "xn--4xa"},
}
func TestEncodeDecodePunycode(t *testing.T) {
for _, tst := range testcases {
enc := encode([]byte(tst[0]))
if string(enc) != tst[1] {
t.Errorf("%s encodeded as %s but should be %s", tst[0], enc, tst[1])
}
dec := decode([]byte(tst[1]))
if string(dec) != strings.ToLower(tst[0]) {
t.Errorf("%s decoded as %s but should be %s", tst[1], dec, strings.ToLower(tst[0]))
}
}
}
func TestToFromPunycode(t *testing.T) {
for _, tst := range testcases {
// assert unicode.com == punycode.com
full := ToPunycode(tst[0] + ".com")
if full != tst[1]+".com" {
t.Errorf("invalid result from string conversion to punycode, %s and should be %s.com", full, tst[1])
}
// assert punycode.punycode == unicode.unicode
decoded := FromPunycode(tst[1] + "." + tst[1])
if decoded != strings.ToLower(tst[0]+"."+tst[0]) {
t.Errorf("invalid result from string conversion to punycode, %s and should be %s.%s", decoded, tst[0], tst[0])
}
}
}
func TestEncodeDecodeFinalPeriod(t *testing.T) {
for _, tst := range testcases {
// assert unicode.com. == punycode.com.
full := ToPunycode(tst[0] + ".")
if full != tst[1]+"." {
t.Errorf("invalid result from string conversion to punycode when period added at the end, %#v and should be %#v", full, tst[1]+".")
}
// assert punycode.com. == unicode.com.
decoded := FromPunycode(tst[1] + ".")
if decoded != strings.ToLower(tst[0]+".") {
t.Errorf("invalid result from string conversion to punycode when period added, %#v and should be %#v", decoded, tst[0]+".")
}
full = ToPunycode(tst[0])
if full != tst[1] {
t.Errorf("invalid result from string conversion to punycode when no period added at the end, %#v and should be %#v", full, tst[1]+".")
}
// assert punycode.com. == unicode.com.
decoded = FromPunycode(tst[1])
if decoded != strings.ToLower(tst[0]) {
t.Errorf("invalid result from string conversion to punycode when no period added, %#v and should be %#v", decoded, tst[0]+".")
}
}
}
var invalidACEs = []string{
"xn--*",
"xn--",
"xn---",
"xn--a000000000",
}
func TestInvalidPunycode(t *testing.T) {
for _, d := range invalidACEs {
s := FromPunycode(d)
if s != d {
t.Errorf("Changed invalid name %s to %#v", d, s)
}
}
}
// You can verify the labels that are valid or not comparing to the Verisign
// website: http://mct.verisign-grs.com/
var invalidUnicodes = []string{
"Σ",
"ЯZ",
"Испытание",
}
func TestInvalidUnicodes(t *testing.T) {
for _, d := range invalidUnicodes {
s := ToPunycode(d)
if s != "" {
t.Errorf("Changed invalid name %s to %#v", d, s)
}
}
}