From baf7141d1dd0f99d561a2197a909c66dd389809d Mon Sep 17 00:00:00 2001 From: Niall Sheridan Date: Sat, 8 Oct 2016 16:02:50 -0500 Subject: Update dependencies --- vendor/golang.org/x/net/idna/punycode.go | 200 +++++++++++++++++++++++++++++++ 1 file changed, 200 insertions(+) create mode 100644 vendor/golang.org/x/net/idna/punycode.go (limited to 'vendor/golang.org/x/net/idna/punycode.go') diff --git a/vendor/golang.org/x/net/idna/punycode.go b/vendor/golang.org/x/net/idna/punycode.go new file mode 100644 index 0000000..92e733f --- /dev/null +++ b/vendor/golang.org/x/net/idna/punycode.go @@ -0,0 +1,200 @@ +// Copyright 2012 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package idna + +// This file implements the Punycode algorithm from RFC 3492. + +import ( + "fmt" + "math" + "strings" + "unicode/utf8" +) + +// These parameter values are specified in section 5. +// +// All computation is done with int32s, so that overflow behavior is identical +// regardless of whether int is 32-bit or 64-bit. +const ( + base int32 = 36 + damp int32 = 700 + initialBias int32 = 72 + initialN int32 = 128 + skew int32 = 38 + tmax int32 = 26 + tmin int32 = 1 +) + +// decode decodes a string as specified in section 6.2. +func decode(encoded string) (string, error) { + if encoded == "" { + return "", nil + } + pos := 1 + strings.LastIndex(encoded, "-") + if pos == 1 { + return "", fmt.Errorf("idna: invalid label %q", encoded) + } + if pos == len(encoded) { + return encoded[:len(encoded)-1], nil + } + output := make([]rune, 0, len(encoded)) + if pos != 0 { + for _, r := range encoded[:pos-1] { + output = append(output, r) + } + } + i, n, bias := int32(0), initialN, initialBias + for pos < len(encoded) { + oldI, w := i, int32(1) + for k := base; ; k += base { + if pos == len(encoded) { + return "", fmt.Errorf("idna: invalid label %q", encoded) + } + digit, ok := decodeDigit(encoded[pos]) + if !ok { + return "", fmt.Errorf("idna: invalid label %q", encoded) + } + pos++ + i += digit * w + if i < 0 { + return "", fmt.Errorf("idna: invalid label %q", encoded) + } + t := k - bias + if t < tmin { + t = tmin + } else if t > tmax { + t = tmax + } + if digit < t { + break + } + w *= base - t + if w >= math.MaxInt32/base { + return "", fmt.Errorf("idna: invalid label %q", encoded) + } + } + x := int32(len(output) + 1) + bias = adapt(i-oldI, x, oldI == 0) + n += i / x + i %= x + if n > utf8.MaxRune || len(output) >= 1024 { + return "", fmt.Errorf("idna: invalid label %q", encoded) + } + output = append(output, 0) + copy(output[i+1:], output[i:]) + output[i] = n + i++ + } + return string(output), nil +} + +// encode encodes a string as specified in section 6.3 and prepends prefix to +// the result. +// +// The "while h < length(input)" line in the specification becomes "for +// remaining != 0" in the Go code, because len(s) in Go is in bytes, not runes. +func encode(prefix, s string) (string, error) { + output := make([]byte, len(prefix), len(prefix)+1+2*len(s)) + copy(output, prefix) + delta, n, bias := int32(0), initialN, initialBias + b, remaining := int32(0), int32(0) + for _, r := range s { + if r < 0x80 { + b++ + output = append(output, byte(r)) + } else { + remaining++ + } + } + h := b + if b > 0 { + output = append(output, '-') + } + for remaining != 0 { + m := int32(0x7fffffff) + for _, r := range s { + if m > r && r >= n { + m = r + } + } + delta += (m - n) * (h + 1) + if delta < 0 { + return "", fmt.Errorf("idna: invalid label %q", s) + } + n = m + for _, r := range s { + if r < n { + delta++ + if delta < 0 { + return "", fmt.Errorf("idna: invalid label %q", s) + } + continue + } + if r > n { + continue + } + q := delta + for k := base; ; k += base { + t := k - bias + if t < tmin { + t = tmin + } else if t > tmax { + t = tmax + } + if q < t { + break + } + output = append(output, encodeDigit(t+(q-t)%(base-t))) + q = (q - t) / (base - t) + } + output = append(output, encodeDigit(q)) + bias = adapt(delta, h+1, h == b) + delta = 0 + h++ + remaining-- + } + delta++ + n++ + } + return string(output), nil +} + +func decodeDigit(x byte) (digit int32, ok bool) { + switch { + case '0' <= x && x <= '9': + return int32(x - ('0' - 26)), true + case 'A' <= x && x <= 'Z': + return int32(x - 'A'), true + case 'a' <= x && x <= 'z': + return int32(x - 'a'), true + } + return 0, false +} + +func encodeDigit(digit int32) byte { + switch { + case 0 <= digit && digit < 26: + return byte(digit + 'a') + case 26 <= digit && digit < 36: + return byte(digit + ('0' - 26)) + } + panic("idna: internal error in punycode encoding") +} + +// adapt is the bias adaptation function specified in section 6.1. +func adapt(delta, numPoints int32, firstTime bool) int32 { + if firstTime { + delta /= damp + } else { + delta /= 2 + } + delta += delta / numPoints + k := int32(0) + for delta > ((base-tmin)*tmax)/2 { + delta /= base - tmin + k += base + } + return k + (base-tmin+1)*delta/(delta+skew) +} -- cgit v1.2.3