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Moved things to subdir and adding functions to convert strings.

This commit is contained in:
Alex Sergeyev 2014-09-10 23:33:26 -04:00
parent e3c2c0734f
commit a906600891
2 changed files with 55 additions and 37 deletions
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77
punycode.go → idn/punycode.go
View File

@ -1,4 +1,4 @@
package dns
package idn
import (
"bytes"
@ -7,31 +7,40 @@ import (
// See http://tools.ietf.org/html/rfc3492
// Implementation idea from RFC itself and from from IDNA::Punycode created by
// Tatsuhiko Miyagawa <miyagawa@bulknews.net> in 2002
// Tatsuhiko Miyagawa <miyagawa@bulknews.net> and released under Perl Artistic
// License in 2002
const (
_MIN = '\u0001'
_MAX = '\u001a' // 26
_SKEW = '\u0026' // 38
_DAMP = '\u02BC' // 700
_BASE = '\u0024' // 36
_BIAS = '\u0048' // 72
_N = '\u0080' // 128
_MIN rune = 1
_MAX rune = 26
_SKEW rune = 38
_DAMP rune = 700
_BASE rune = 36
_BIAS rune = 72
_N rune = 128
Delimiter = '-'
Prefix = "xn--"
_DELIMITER = '-'
_PREFIX = "xn--"
)
func IdnToASCII(string) string {
return ""
func ToPunycode(s string) string {
tokens := bytes.Split([]byte(s), []byte{'.'})
for i := range tokens {
tokens[i] = encodeBytes(tokens[i])
}
return string(bytes.Join(tokens, []byte{'.'}))
}
func IdnFromASCII(string) string {
return ""
func FromPunycode(s string) string {
tokens := bytes.Split([]byte(s), []byte{'.'})
for i := range tokens {
tokens[i] = decodeBytes(tokens[i])
}
return string(bytes.Join(tokens, []byte{'.'}))
}
// digit_value convert single byte into meaningful value that's used to calculate decoded unicode character.
func digit_value(code rune) rune {
// digitval converts single byte into meaningful value that's used to calculate decoded unicode character.
func digitval(code rune) rune {
switch {
case code >= 'A' && code <= 'Z':
return code - 'A'
@ -43,8 +52,8 @@ func digit_value(code rune) rune {
panic("never happens")
}
// code_point finds BASE36 byte (a-z0-9) based on calculated number.
func code_point(digit rune) rune {
// 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'
@ -55,7 +64,7 @@ func code_point(digit rune) rune {
}
// adapt calculates next bias to be used for next iteration delta
func adapt_bias(delta rune, numpoints rune, firsttime bool) rune {
func adapt(delta rune, numpoints rune, firsttime bool) rune {
if firsttime {
delta /= _DAMP
} else {
@ -106,8 +115,8 @@ func tfunc(k, bias rune) rune {
return k - bias
}
// encode_punycode transforms Unicode input bytes (that represent DNS label) into punycode bytestream
func encode_punycode(input []byte) []byte {
// encodeBytes transforms Unicode input bytes (that represent DNS label) into punycode bytestream
func encodeBytes(input []byte) []byte {
n, delta, bias := _N, rune(0), _BIAS
b := bytes.Runes(input)
@ -129,10 +138,10 @@ func encode_punycode(input []byte) []byte {
var out bytes.Buffer
out.WriteString(Prefix)
out.WriteString(_PREFIX)
if basiclen > 0 {
out.Write(basic)
out.WriteByte(Delimiter)
out.WriteByte(_DELIMITER)
}
for h := basiclen; h < fulllen; n, delta = n+1, delta+1 {
@ -153,13 +162,13 @@ func encode_punycode(input []byte) []byte {
break
}
cp := t + ((q - t) % (_BASE - t))
out.WriteRune(code_point(cp))
out.WriteRune(lettercode(cp))
q = (q - t) / (_BASE - t)
}
out.WriteRune(code_point(q))
out.WriteRune(lettercode(q))
bias = adapt_bias(delta, h+1, h == basiclen)
bias = adapt(delta, h+1, h == basiclen)
h, delta = h+1, 0
}
}
@ -167,15 +176,15 @@ func encode_punycode(input []byte) []byte {
return out.Bytes()
}
// encode_punycode transforms punycode input bytes (that represent DNS label) into Unicode bytestream
func decode_punycode(b []byte) []byte {
// decodeBytes transforms punycode input bytes (that represent DNS label) into Unicode bytestream
func decodeBytes(b []byte) []byte {
n, bias := _N, _BIAS
if !bytes.HasPrefix(b, []byte(Prefix)) {
if !bytes.HasPrefix(b, []byte(_PREFIX)) {
return b
}
out := make([]rune, 0, len(b))
b = b[len(Prefix):]
pos := bytes.Index(b, []byte{Delimiter})
b = b[len(_PREFIX):]
pos := bytes.Index(b, []byte{_DELIMITER})
if pos >= 0 {
out = append(out, bytes.Runes(b[:pos])...)
b = b[pos+1:] // trim source string
@ -184,7 +193,7 @@ func decode_punycode(b []byte) []byte {
oldi, w, ch := i, rune(1), byte(0)
for k := _BASE; ; k += _BASE {
ch, b = b[0], b[1:]
digit := digit_value(rune(ch))
digit := digitval(rune(ch))
i += digit * w
t := tfunc(k, bias)
@ -195,7 +204,7 @@ func decode_punycode(b []byte) []byte {
w *= _BASE - t
}
ln := rune(len(out) + 1)
bias = adapt_bias(i-oldi, ln, oldi == 0)
bias = adapt(i-oldi, ln, oldi == 0)
n += i / ln
i = i % ln
// insert

15
punycode_test.go → idn/punycode_test.go
View File

@ -1,4 +1,4 @@
package dns
package idn
import (
"strings"
@ -27,13 +27,22 @@ var testcases = [][2]string{
func TestEncodePunycode(t *testing.T) {
for _, tst := range testcases {
enc := encode_punycode([]byte(tst[0]))
enc := encodeBytes([]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_punycode([]byte(tst[1]))
dec := decodeBytes([]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]))
}
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])
}
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])
}
}
}