mirror of
https://github.com/superseriousbusiness/gotosocial.git
synced 2024-11-30 15:42:46 +00:00
484 lines
12 KiB
Go
484 lines
12 KiB
Go
// This files's string processing codes are inspired by https://github.com/segmentio/encoding.
|
|
// The license notation is as follows.
|
|
//
|
|
// # MIT License
|
|
//
|
|
// Copyright (c) 2019 Segment.io, Inc.
|
|
//
|
|
// Permission is hereby granted, free of charge, to any person obtaining a copy
|
|
// of this software and associated documentation files (the "Software"), to deal
|
|
// in the Software without restriction, including without limitation the rights
|
|
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
|
|
// copies of the Software, and to permit persons to whom the Software is
|
|
// furnished to do so, subject to the following conditions:
|
|
//
|
|
// The above copyright notice and this permission notice shall be included in all
|
|
// copies or substantial portions of the Software.
|
|
//
|
|
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
|
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
|
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
|
|
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
|
|
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
|
|
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
|
|
// SOFTWARE.
|
|
package encoder
|
|
|
|
import (
|
|
"math/bits"
|
|
"reflect"
|
|
"unsafe"
|
|
)
|
|
|
|
const (
|
|
lsb = 0x0101010101010101
|
|
msb = 0x8080808080808080
|
|
)
|
|
|
|
var hex = "0123456789abcdef"
|
|
|
|
//nolint:govet
|
|
func stringToUint64Slice(s string) []uint64 {
|
|
return *(*[]uint64)(unsafe.Pointer(&reflect.SliceHeader{
|
|
Data: ((*reflect.StringHeader)(unsafe.Pointer(&s))).Data,
|
|
Len: len(s) / 8,
|
|
Cap: len(s) / 8,
|
|
}))
|
|
}
|
|
|
|
func AppendString(ctx *RuntimeContext, buf []byte, s string) []byte {
|
|
if ctx.Option.Flag&HTMLEscapeOption != 0 {
|
|
if ctx.Option.Flag&NormalizeUTF8Option != 0 {
|
|
return appendNormalizedHTMLString(buf, s)
|
|
}
|
|
return appendHTMLString(buf, s)
|
|
}
|
|
if ctx.Option.Flag&NormalizeUTF8Option != 0 {
|
|
return appendNormalizedString(buf, s)
|
|
}
|
|
return appendString(buf, s)
|
|
}
|
|
|
|
func appendNormalizedHTMLString(buf []byte, s string) []byte {
|
|
valLen := len(s)
|
|
if valLen == 0 {
|
|
return append(buf, `""`...)
|
|
}
|
|
buf = append(buf, '"')
|
|
var (
|
|
i, j int
|
|
)
|
|
if valLen >= 8 {
|
|
chunks := stringToUint64Slice(s)
|
|
for _, n := range chunks {
|
|
// combine masks before checking for the MSB of each byte. We include
|
|
// `n` in the mask to check whether any of the *input* byte MSBs were
|
|
// set (i.e. the byte was outside the ASCII range).
|
|
mask := n | (n - (lsb * 0x20)) |
|
|
((n ^ (lsb * '"')) - lsb) |
|
|
((n ^ (lsb * '\\')) - lsb) |
|
|
((n ^ (lsb * '<')) - lsb) |
|
|
((n ^ (lsb * '>')) - lsb) |
|
|
((n ^ (lsb * '&')) - lsb)
|
|
if (mask & msb) != 0 {
|
|
j = bits.TrailingZeros64(mask&msb) / 8
|
|
goto ESCAPE_END
|
|
}
|
|
}
|
|
for i := len(chunks) * 8; i < valLen; i++ {
|
|
if needEscapeHTMLNormalizeUTF8[s[i]] {
|
|
j = i
|
|
goto ESCAPE_END
|
|
}
|
|
}
|
|
// no found any escape characters.
|
|
return append(append(buf, s...), '"')
|
|
}
|
|
ESCAPE_END:
|
|
for j < valLen {
|
|
c := s[j]
|
|
|
|
if !needEscapeHTMLNormalizeUTF8[c] {
|
|
// fast path: most of the time, printable ascii characters are used
|
|
j++
|
|
continue
|
|
}
|
|
|
|
switch c {
|
|
case '\\', '"':
|
|
buf = append(buf, s[i:j]...)
|
|
buf = append(buf, '\\', c)
|
|
i = j + 1
|
|
j = j + 1
|
|
continue
|
|
|
|
case '\n':
|
|
buf = append(buf, s[i:j]...)
|
|
buf = append(buf, '\\', 'n')
|
|
i = j + 1
|
|
j = j + 1
|
|
continue
|
|
|
|
case '\r':
|
|
buf = append(buf, s[i:j]...)
|
|
buf = append(buf, '\\', 'r')
|
|
i = j + 1
|
|
j = j + 1
|
|
continue
|
|
|
|
case '\t':
|
|
buf = append(buf, s[i:j]...)
|
|
buf = append(buf, '\\', 't')
|
|
i = j + 1
|
|
j = j + 1
|
|
continue
|
|
|
|
case '<', '>', '&':
|
|
buf = append(buf, s[i:j]...)
|
|
buf = append(buf, `\u00`...)
|
|
buf = append(buf, hex[c>>4], hex[c&0xF])
|
|
i = j + 1
|
|
j = j + 1
|
|
continue
|
|
|
|
case 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x0B, 0x0C, 0x0E, 0x0F, // 0x00-0x0F
|
|
0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F: // 0x10-0x1F
|
|
buf = append(buf, s[i:j]...)
|
|
buf = append(buf, `\u00`...)
|
|
buf = append(buf, hex[c>>4], hex[c&0xF])
|
|
i = j + 1
|
|
j = j + 1
|
|
continue
|
|
}
|
|
state, size := decodeRuneInString(s[j:])
|
|
switch state {
|
|
case runeErrorState:
|
|
buf = append(buf, s[i:j]...)
|
|
buf = append(buf, `\ufffd`...)
|
|
i = j + 1
|
|
j = j + 1
|
|
continue
|
|
// U+2028 is LINE SEPARATOR.
|
|
// U+2029 is PARAGRAPH SEPARATOR.
|
|
// They are both technically valid characters in JSON strings,
|
|
// but don't work in JSONP, which has to be evaluated as JavaScript,
|
|
// and can lead to security holes there. It is valid JSON to
|
|
// escape them, so we do so unconditionally.
|
|
// See http://timelessrepo.com/json-isnt-a-javascript-subset for discussion.
|
|
case lineSepState:
|
|
buf = append(buf, s[i:j]...)
|
|
buf = append(buf, `\u2028`...)
|
|
i = j + 3
|
|
j = j + 3
|
|
continue
|
|
case paragraphSepState:
|
|
buf = append(buf, s[i:j]...)
|
|
buf = append(buf, `\u2029`...)
|
|
i = j + 3
|
|
j = j + 3
|
|
continue
|
|
}
|
|
j += size
|
|
}
|
|
|
|
return append(append(buf, s[i:]...), '"')
|
|
}
|
|
|
|
func appendHTMLString(buf []byte, s string) []byte {
|
|
valLen := len(s)
|
|
if valLen == 0 {
|
|
return append(buf, `""`...)
|
|
}
|
|
buf = append(buf, '"')
|
|
var (
|
|
i, j int
|
|
)
|
|
if valLen >= 8 {
|
|
chunks := stringToUint64Slice(s)
|
|
for _, n := range chunks {
|
|
// combine masks before checking for the MSB of each byte. We include
|
|
// `n` in the mask to check whether any of the *input* byte MSBs were
|
|
// set (i.e. the byte was outside the ASCII range).
|
|
mask := n | (n - (lsb * 0x20)) |
|
|
((n ^ (lsb * '"')) - lsb) |
|
|
((n ^ (lsb * '\\')) - lsb) |
|
|
((n ^ (lsb * '<')) - lsb) |
|
|
((n ^ (lsb * '>')) - lsb) |
|
|
((n ^ (lsb * '&')) - lsb)
|
|
if (mask & msb) != 0 {
|
|
j = bits.TrailingZeros64(mask&msb) / 8
|
|
goto ESCAPE_END
|
|
}
|
|
}
|
|
for i := len(chunks) * 8; i < valLen; i++ {
|
|
if needEscapeHTML[s[i]] {
|
|
j = i
|
|
goto ESCAPE_END
|
|
}
|
|
}
|
|
// no found any escape characters.
|
|
return append(append(buf, s...), '"')
|
|
}
|
|
ESCAPE_END:
|
|
for j < valLen {
|
|
c := s[j]
|
|
|
|
if !needEscapeHTML[c] {
|
|
// fast path: most of the time, printable ascii characters are used
|
|
j++
|
|
continue
|
|
}
|
|
|
|
switch c {
|
|
case '\\', '"':
|
|
buf = append(buf, s[i:j]...)
|
|
buf = append(buf, '\\', c)
|
|
i = j + 1
|
|
j = j + 1
|
|
continue
|
|
|
|
case '\n':
|
|
buf = append(buf, s[i:j]...)
|
|
buf = append(buf, '\\', 'n')
|
|
i = j + 1
|
|
j = j + 1
|
|
continue
|
|
|
|
case '\r':
|
|
buf = append(buf, s[i:j]...)
|
|
buf = append(buf, '\\', 'r')
|
|
i = j + 1
|
|
j = j + 1
|
|
continue
|
|
|
|
case '\t':
|
|
buf = append(buf, s[i:j]...)
|
|
buf = append(buf, '\\', 't')
|
|
i = j + 1
|
|
j = j + 1
|
|
continue
|
|
|
|
case '<', '>', '&':
|
|
buf = append(buf, s[i:j]...)
|
|
buf = append(buf, `\u00`...)
|
|
buf = append(buf, hex[c>>4], hex[c&0xF])
|
|
i = j + 1
|
|
j = j + 1
|
|
continue
|
|
|
|
case 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x0B, 0x0C, 0x0E, 0x0F, // 0x00-0x0F
|
|
0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F: // 0x10-0x1F
|
|
buf = append(buf, s[i:j]...)
|
|
buf = append(buf, `\u00`...)
|
|
buf = append(buf, hex[c>>4], hex[c&0xF])
|
|
i = j + 1
|
|
j = j + 1
|
|
continue
|
|
}
|
|
j++
|
|
}
|
|
|
|
return append(append(buf, s[i:]...), '"')
|
|
}
|
|
|
|
func appendNormalizedString(buf []byte, s string) []byte {
|
|
valLen := len(s)
|
|
if valLen == 0 {
|
|
return append(buf, `""`...)
|
|
}
|
|
buf = append(buf, '"')
|
|
var (
|
|
i, j int
|
|
)
|
|
if valLen >= 8 {
|
|
chunks := stringToUint64Slice(s)
|
|
for _, n := range chunks {
|
|
// combine masks before checking for the MSB of each byte. We include
|
|
// `n` in the mask to check whether any of the *input* byte MSBs were
|
|
// set (i.e. the byte was outside the ASCII range).
|
|
mask := n | (n - (lsb * 0x20)) |
|
|
((n ^ (lsb * '"')) - lsb) |
|
|
((n ^ (lsb * '\\')) - lsb)
|
|
if (mask & msb) != 0 {
|
|
j = bits.TrailingZeros64(mask&msb) / 8
|
|
goto ESCAPE_END
|
|
}
|
|
}
|
|
valLen := len(s)
|
|
for i := len(chunks) * 8; i < valLen; i++ {
|
|
if needEscapeNormalizeUTF8[s[i]] {
|
|
j = i
|
|
goto ESCAPE_END
|
|
}
|
|
}
|
|
return append(append(buf, s...), '"')
|
|
}
|
|
ESCAPE_END:
|
|
for j < valLen {
|
|
c := s[j]
|
|
|
|
if !needEscapeNormalizeUTF8[c] {
|
|
// fast path: most of the time, printable ascii characters are used
|
|
j++
|
|
continue
|
|
}
|
|
|
|
switch c {
|
|
case '\\', '"':
|
|
buf = append(buf, s[i:j]...)
|
|
buf = append(buf, '\\', c)
|
|
i = j + 1
|
|
j = j + 1
|
|
continue
|
|
|
|
case '\n':
|
|
buf = append(buf, s[i:j]...)
|
|
buf = append(buf, '\\', 'n')
|
|
i = j + 1
|
|
j = j + 1
|
|
continue
|
|
|
|
case '\r':
|
|
buf = append(buf, s[i:j]...)
|
|
buf = append(buf, '\\', 'r')
|
|
i = j + 1
|
|
j = j + 1
|
|
continue
|
|
|
|
case '\t':
|
|
buf = append(buf, s[i:j]...)
|
|
buf = append(buf, '\\', 't')
|
|
i = j + 1
|
|
j = j + 1
|
|
continue
|
|
|
|
case 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x0B, 0x0C, 0x0E, 0x0F, // 0x00-0x0F
|
|
0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F: // 0x10-0x1F
|
|
buf = append(buf, s[i:j]...)
|
|
buf = append(buf, `\u00`...)
|
|
buf = append(buf, hex[c>>4], hex[c&0xF])
|
|
i = j + 1
|
|
j = j + 1
|
|
continue
|
|
}
|
|
|
|
state, size := decodeRuneInString(s[j:])
|
|
switch state {
|
|
case runeErrorState:
|
|
buf = append(buf, s[i:j]...)
|
|
buf = append(buf, `\ufffd`...)
|
|
i = j + 1
|
|
j = j + 1
|
|
continue
|
|
// U+2028 is LINE SEPARATOR.
|
|
// U+2029 is PARAGRAPH SEPARATOR.
|
|
// They are both technically valid characters in JSON strings,
|
|
// but don't work in JSONP, which has to be evaluated as JavaScript,
|
|
// and can lead to security holes there. It is valid JSON to
|
|
// escape them, so we do so unconditionally.
|
|
// See http://timelessrepo.com/json-isnt-a-javascript-subset for discussion.
|
|
case lineSepState:
|
|
buf = append(buf, s[i:j]...)
|
|
buf = append(buf, `\u2028`...)
|
|
i = j + 3
|
|
j = j + 3
|
|
continue
|
|
case paragraphSepState:
|
|
buf = append(buf, s[i:j]...)
|
|
buf = append(buf, `\u2029`...)
|
|
i = j + 3
|
|
j = j + 3
|
|
continue
|
|
}
|
|
j += size
|
|
}
|
|
|
|
return append(append(buf, s[i:]...), '"')
|
|
}
|
|
|
|
func appendString(buf []byte, s string) []byte {
|
|
valLen := len(s)
|
|
if valLen == 0 {
|
|
return append(buf, `""`...)
|
|
}
|
|
buf = append(buf, '"')
|
|
var (
|
|
i, j int
|
|
)
|
|
if valLen >= 8 {
|
|
chunks := stringToUint64Slice(s)
|
|
for _, n := range chunks {
|
|
// combine masks before checking for the MSB of each byte. We include
|
|
// `n` in the mask to check whether any of the *input* byte MSBs were
|
|
// set (i.e. the byte was outside the ASCII range).
|
|
mask := n | (n - (lsb * 0x20)) |
|
|
((n ^ (lsb * '"')) - lsb) |
|
|
((n ^ (lsb * '\\')) - lsb)
|
|
if (mask & msb) != 0 {
|
|
j = bits.TrailingZeros64(mask&msb) / 8
|
|
goto ESCAPE_END
|
|
}
|
|
}
|
|
valLen := len(s)
|
|
for i := len(chunks) * 8; i < valLen; i++ {
|
|
if needEscape[s[i]] {
|
|
j = i
|
|
goto ESCAPE_END
|
|
}
|
|
}
|
|
return append(append(buf, s...), '"')
|
|
}
|
|
ESCAPE_END:
|
|
for j < valLen {
|
|
c := s[j]
|
|
|
|
if !needEscape[c] {
|
|
// fast path: most of the time, printable ascii characters are used
|
|
j++
|
|
continue
|
|
}
|
|
|
|
switch c {
|
|
case '\\', '"':
|
|
buf = append(buf, s[i:j]...)
|
|
buf = append(buf, '\\', c)
|
|
i = j + 1
|
|
j = j + 1
|
|
continue
|
|
|
|
case '\n':
|
|
buf = append(buf, s[i:j]...)
|
|
buf = append(buf, '\\', 'n')
|
|
i = j + 1
|
|
j = j + 1
|
|
continue
|
|
|
|
case '\r':
|
|
buf = append(buf, s[i:j]...)
|
|
buf = append(buf, '\\', 'r')
|
|
i = j + 1
|
|
j = j + 1
|
|
continue
|
|
|
|
case '\t':
|
|
buf = append(buf, s[i:j]...)
|
|
buf = append(buf, '\\', 't')
|
|
i = j + 1
|
|
j = j + 1
|
|
continue
|
|
|
|
case 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x0B, 0x0C, 0x0E, 0x0F, // 0x00-0x0F
|
|
0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F: // 0x10-0x1F
|
|
buf = append(buf, s[i:j]...)
|
|
buf = append(buf, `\u00`...)
|
|
buf = append(buf, hex[c>>4], hex[c&0xF])
|
|
i = j + 1
|
|
j = j + 1
|
|
continue
|
|
}
|
|
j++
|
|
}
|
|
|
|
return append(append(buf, s[i:]...), '"')
|
|
}
|