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Add support for negotiating IMAP and SMTP on the HTTPS port 443 using TLS ALPN "imap" and "smtp"

Browse Source 
Intended for future use with chatmail servers. Standard email ports may be
blocked on some networks, while the HTTPS port may be accessible.

This is a squashed commit of PR #255 by s0ph0s-dog.
This commit is contained in:
s0ph0s
2025-01-23 11:13:06 +01:00
committed by Mechiel Lukkien
parent 0203dfa9d9
commit 3c77e076e2
49 changed files with 14832 additions and 86 deletions
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245
vendor/golang.org/x/net/http2/hpack/encode.go generated vendored Normal file
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// Copyright 2014 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 hpack
import (
"io"
)
const (
uint32Max = ^uint32(0)
initialHeaderTableSize = 4096
)
type Encoder struct {
dynTab dynamicTable
// minSize is the minimum table size set by
// SetMaxDynamicTableSize after the previous Header Table Size
// Update.
minSize uint32
// maxSizeLimit is the maximum table size this encoder
// supports. This will protect the encoder from too large
// size.
maxSizeLimit uint32
// tableSizeUpdate indicates whether "Header Table Size
// Update" is required.
tableSizeUpdate bool
w io.Writer
buf []byte
}
// NewEncoder returns a new Encoder which performs HPACK encoding. An
// encoded data is written to w.
func NewEncoder(w io.Writer) *Encoder {
e := &Encoder{
minSize: uint32Max,
maxSizeLimit: initialHeaderTableSize,
tableSizeUpdate: false,
w: w,
}
e.dynTab.table.init()
e.dynTab.setMaxSize(initialHeaderTableSize)
return e
}
// WriteField encodes f into a single Write to e's underlying Writer.
// This function may also produce bytes for "Header Table Size Update"
// if necessary. If produced, it is done before encoding f.
func (e *Encoder) WriteField(f HeaderField) error {
e.buf = e.buf[:0]
if e.tableSizeUpdate {
e.tableSizeUpdate = false
if e.minSize < e.dynTab.maxSize {
e.buf = appendTableSize(e.buf, e.minSize)
}
e.minSize = uint32Max
e.buf = appendTableSize(e.buf, e.dynTab.maxSize)
}
idx, nameValueMatch := e.searchTable(f)
if nameValueMatch {
e.buf = appendIndexed(e.buf, idx)
} else {
indexing := e.shouldIndex(f)
if indexing {
e.dynTab.add(f)
}
if idx == 0 {
e.buf = appendNewName(e.buf, f, indexing)
} else {
e.buf = appendIndexedName(e.buf, f, idx, indexing)
}
}
n, err := e.w.Write(e.buf)
if err == nil && n != len(e.buf) {
err = io.ErrShortWrite
}
return err
}
// searchTable searches f in both stable and dynamic header tables.
// The static header table is searched first. Only when there is no
// exact match for both name and value, the dynamic header table is
// then searched. If there is no match, i is 0. If both name and value
// match, i is the matched index and nameValueMatch becomes true. If
// only name matches, i points to that index and nameValueMatch
// becomes false.
func (e *Encoder) searchTable(f HeaderField) (i uint64, nameValueMatch bool) {
i, nameValueMatch = staticTable.search(f)
if nameValueMatch {
return i, true
}
j, nameValueMatch := e.dynTab.table.search(f)
if nameValueMatch || (i == 0 && j != 0) {
return j + uint64(staticTable.len()), nameValueMatch
}
return i, false
}
// SetMaxDynamicTableSize changes the dynamic header table size to v.
// The actual size is bounded by the value passed to
// SetMaxDynamicTableSizeLimit.
func (e *Encoder) SetMaxDynamicTableSize(v uint32) {
if v > e.maxSizeLimit {
v = e.maxSizeLimit
}
if v < e.minSize {
e.minSize = v
}
e.tableSizeUpdate = true
e.dynTab.setMaxSize(v)
}
// MaxDynamicTableSize returns the current dynamic header table size.
func (e *Encoder) MaxDynamicTableSize() (v uint32) {
return e.dynTab.maxSize
}
// SetMaxDynamicTableSizeLimit changes the maximum value that can be
// specified in SetMaxDynamicTableSize to v. By default, it is set to
// 4096, which is the same size of the default dynamic header table
// size described in HPACK specification. If the current maximum
// dynamic header table size is strictly greater than v, "Header Table
// Size Update" will be done in the next WriteField call and the
// maximum dynamic header table size is truncated to v.
func (e *Encoder) SetMaxDynamicTableSizeLimit(v uint32) {
e.maxSizeLimit = v
if e.dynTab.maxSize > v {
e.tableSizeUpdate = true
e.dynTab.setMaxSize(v)
}
}
// shouldIndex reports whether f should be indexed.
func (e *Encoder) shouldIndex(f HeaderField) bool {
return !f.Sensitive && f.Size() <= e.dynTab.maxSize
}
// appendIndexed appends index i, as encoded in "Indexed Header Field"
// representation, to dst and returns the extended buffer.
func appendIndexed(dst []byte, i uint64) []byte {
first := len(dst)
dst = appendVarInt(dst, 7, i)
dst[first] |= 0x80
return dst
}
// appendNewName appends f, as encoded in one of "Literal Header field
// - New Name" representation variants, to dst and returns the
// extended buffer.
//
// If f.Sensitive is true, "Never Indexed" representation is used. If
// f.Sensitive is false and indexing is true, "Incremental Indexing"
// representation is used.
func appendNewName(dst []byte, f HeaderField, indexing bool) []byte {
dst = append(dst, encodeTypeByte(indexing, f.Sensitive))
dst = appendHpackString(dst, f.Name)
return appendHpackString(dst, f.Value)
}
// appendIndexedName appends f and index i referring indexed name
// entry, as encoded in one of "Literal Header field - Indexed Name"
// representation variants, to dst and returns the extended buffer.
//
// If f.Sensitive is true, "Never Indexed" representation is used. If
// f.Sensitive is false and indexing is true, "Incremental Indexing"
// representation is used.
func appendIndexedName(dst []byte, f HeaderField, i uint64, indexing bool) []byte {
first := len(dst)
var n byte
if indexing {
n = 6
} else {
n = 4
}
dst = appendVarInt(dst, n, i)
dst[first] |= encodeTypeByte(indexing, f.Sensitive)
return appendHpackString(dst, f.Value)
}
// appendTableSize appends v, as encoded in "Header Table Size Update"
// representation, to dst and returns the extended buffer.
func appendTableSize(dst []byte, v uint32) []byte {
first := len(dst)
dst = appendVarInt(dst, 5, uint64(v))
dst[first] |= 0x20
return dst
}
// appendVarInt appends i, as encoded in variable integer form using n
// bit prefix, to dst and returns the extended buffer.
//
// See
// https://httpwg.org/specs/rfc7541.html#integer.representation
func appendVarInt(dst []byte, n byte, i uint64) []byte {
k := uint64((1 << n) - 1)
if i < k {
return append(dst, byte(i))
}
dst = append(dst, byte(k))
i -= k
for ; i >= 128; i >>= 7 {
dst = append(dst, byte(0x80|(i&0x7f)))
}
return append(dst, byte(i))
}
// appendHpackString appends s, as encoded in "String Literal"
// representation, to dst and returns the extended buffer.
//
// s will be encoded in Huffman codes only when it produces strictly
// shorter byte string.
func appendHpackString(dst []byte, s string) []byte {
huffmanLength := HuffmanEncodeLength(s)
if huffmanLength < uint64(len(s)) {
first := len(dst)
dst = appendVarInt(dst, 7, huffmanLength)
dst = AppendHuffmanString(dst, s)
dst[first] |= 0x80
} else {
dst = appendVarInt(dst, 7, uint64(len(s)))
dst = append(dst, s...)
}
return dst
}
// encodeTypeByte returns type byte. If sensitive is true, type byte
// for "Never Indexed" representation is returned. If sensitive is
// false and indexing is true, type byte for "Incremental Indexing"
// representation is returned. Otherwise, type byte for "Without
// Indexing" is returned.
func encodeTypeByte(indexing, sensitive bool) byte {
if sensitive {
return 0x10
}
if indexing {
return 0x40
}
return 0
}

523
vendor/golang.org/x/net/http2/hpack/hpack.go generated vendored Normal file
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// Copyright 2014 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 hpack implements HPACK, a compression format for
// efficiently representing HTTP header fields in the context of HTTP/2.
//
// See http://tools.ietf.org/html/draft-ietf-httpbis-header-compression-09
package hpack
import (
"bytes"
"errors"
"fmt"
)
// A DecodingError is something the spec defines as a decoding error.
type DecodingError struct {
Err error
}
func (de DecodingError) Error() string {
return fmt.Sprintf("decoding error: %v", de.Err)
}
// An InvalidIndexError is returned when an encoder references a table
// entry before the static table or after the end of the dynamic table.
type InvalidIndexError int
func (e InvalidIndexError) Error() string {
return fmt.Sprintf("invalid indexed representation index %d", int(e))
}
// A HeaderField is a name-value pair. Both the name and value are
// treated as opaque sequences of octets.
type HeaderField struct {
Name, Value string
// Sensitive means that this header field should never be
// indexed.
Sensitive bool
}
// IsPseudo reports whether the header field is an http2 pseudo header.
// That is, it reports whether it starts with a colon.
// It is not otherwise guaranteed to be a valid pseudo header field,
// though.
func (hf HeaderField) IsPseudo() bool {
return len(hf.Name) != 0 && hf.Name[0] == ':'
}
func (hf HeaderField) String() string {
var suffix string
if hf.Sensitive {
suffix = " (sensitive)"
}
return fmt.Sprintf("header field %q = %q%s", hf.Name, hf.Value, suffix)
}
// Size returns the size of an entry per RFC 7541 section 4.1.
func (hf HeaderField) Size() uint32 {
// https://httpwg.org/specs/rfc7541.html#rfc.section.4.1
// "The size of the dynamic table is the sum of the size of
// its entries. The size of an entry is the sum of its name's
// length in octets (as defined in Section 5.2), its value's
// length in octets (see Section 5.2), plus 32. The size of
// an entry is calculated using the length of the name and
// value without any Huffman encoding applied."
// This can overflow if somebody makes a large HeaderField
// Name and/or Value by hand, but we don't care, because that
// won't happen on the wire because the encoding doesn't allow
// it.
return uint32(len(hf.Name) + len(hf.Value) + 32)
}
// A Decoder is the decoding context for incremental processing of
// header blocks.
type Decoder struct {
dynTab dynamicTable
emit func(f HeaderField)
emitEnabled bool // whether calls to emit are enabled
maxStrLen int // 0 means unlimited
// buf is the unparsed buffer. It's only written to
// saveBuf if it was truncated in the middle of a header
// block. Because it's usually not owned, we can only
// process it under Write.
buf []byte // not owned; only valid during Write
// saveBuf is previous data passed to Write which we weren't able
// to fully parse before. Unlike buf, we own this data.
saveBuf bytes.Buffer
firstField bool // processing the first field of the header block
}
// NewDecoder returns a new decoder with the provided maximum dynamic
// table size. The emitFunc will be called for each valid field
// parsed, in the same goroutine as calls to Write, before Write returns.
func NewDecoder(maxDynamicTableSize uint32, emitFunc func(f HeaderField)) *Decoder {
d := &Decoder{
emit: emitFunc,
emitEnabled: true,
firstField: true,
}
d.dynTab.table.init()
d.dynTab.allowedMaxSize = maxDynamicTableSize
d.dynTab.setMaxSize(maxDynamicTableSize)
return d
}
// ErrStringLength is returned by Decoder.Write when the max string length
// (as configured by Decoder.SetMaxStringLength) would be violated.
var ErrStringLength = errors.New("hpack: string too long")
// SetMaxStringLength sets the maximum size of a HeaderField name or
// value string. If a string exceeds this length (even after any
// decompression), Write will return ErrStringLength.
// A value of 0 means unlimited and is the default from NewDecoder.
func (d *Decoder) SetMaxStringLength(n int) {
d.maxStrLen = n
}
// SetEmitFunc changes the callback used when new header fields
// are decoded.
// It must be non-nil. It does not affect EmitEnabled.
func (d *Decoder) SetEmitFunc(emitFunc func(f HeaderField)) {
d.emit = emitFunc
}
// SetEmitEnabled controls whether the emitFunc provided to NewDecoder
// should be called. The default is true.
//
// This facility exists to let servers enforce MAX_HEADER_LIST_SIZE
// while still decoding and keeping in-sync with decoder state, but
// without doing unnecessary decompression or generating unnecessary
// garbage for header fields past the limit.
func (d *Decoder) SetEmitEnabled(v bool) { d.emitEnabled = v }
// EmitEnabled reports whether calls to the emitFunc provided to NewDecoder
// are currently enabled. The default is true.
func (d *Decoder) EmitEnabled() bool { return d.emitEnabled }
// TODO: add method *Decoder.Reset(maxSize, emitFunc) to let callers re-use Decoders and their
// underlying buffers for garbage reasons.
func (d *Decoder) SetMaxDynamicTableSize(v uint32) {
d.dynTab.setMaxSize(v)
}
// SetAllowedMaxDynamicTableSize sets the upper bound that the encoded
// stream (via dynamic table size updates) may set the maximum size
// to.
func (d *Decoder) SetAllowedMaxDynamicTableSize(v uint32) {
d.dynTab.allowedMaxSize = v
}
type dynamicTable struct {
// https://httpwg.org/specs/rfc7541.html#rfc.section.2.3.2
table headerFieldTable
size uint32 // in bytes
maxSize uint32 // current maxSize
allowedMaxSize uint32 // maxSize may go up to this, inclusive
}
func (dt *dynamicTable) setMaxSize(v uint32) {
dt.maxSize = v
dt.evict()
}
func (dt *dynamicTable) add(f HeaderField) {
dt.table.addEntry(f)
dt.size += f.Size()
dt.evict()
}
// If we're too big, evict old stuff.
func (dt *dynamicTable) evict() {
var n int
for dt.size > dt.maxSize && n < dt.table.len() {
dt.size -= dt.table.ents[n].Size()
n++
}
dt.table.evictOldest(n)
}
func (d *Decoder) maxTableIndex() int {
// This should never overflow. RFC 7540 Section 6.5.2 limits the size of
// the dynamic table to 2^32 bytes, where each entry will occupy more than
// one byte. Further, the staticTable has a fixed, small length.
return d.dynTab.table.len() + staticTable.len()
}
func (d *Decoder) at(i uint64) (hf HeaderField, ok bool) {
// See Section 2.3.3.
if i == 0 {
return
}
if i <= uint64(staticTable.len()) {
return staticTable.ents[i-1], true
}
if i > uint64(d.maxTableIndex()) {
return
}
// In the dynamic table, newer entries have lower indices.
// However, dt.ents[0] is the oldest entry. Hence, dt.ents is
// the reversed dynamic table.
dt := d.dynTab.table
return dt.ents[dt.len()-(int(i)-staticTable.len())], true
}
// DecodeFull decodes an entire block.
//
// TODO: remove this method and make it incremental later? This is
// easier for debugging now.
func (d *Decoder) DecodeFull(p []byte) ([]HeaderField, error) {
var hf []HeaderField
saveFunc := d.emit
defer func() { d.emit = saveFunc }()
d.emit = func(f HeaderField) { hf = append(hf, f) }
if _, err := d.Write(p); err != nil {
return nil, err
}
if err := d.Close(); err != nil {
return nil, err
}
return hf, nil
}
// Close declares that the decoding is complete and resets the Decoder
// to be reused again for a new header block. If there is any remaining
// data in the decoder's buffer, Close returns an error.
func (d *Decoder) Close() error {
if d.saveBuf.Len() > 0 {
d.saveBuf.Reset()
return DecodingError{errors.New("truncated headers")}
}
d.firstField = true
return nil
}
func (d *Decoder) Write(p []byte) (n int, err error) {
if len(p) == 0 {
// Prevent state machine CPU attacks (making us redo
// work up to the point of finding out we don't have
// enough data)
return
}
// Only copy the data if we have to. Optimistically assume
// that p will contain a complete header block.
if d.saveBuf.Len() == 0 {
d.buf = p
} else {
d.saveBuf.Write(p)
d.buf = d.saveBuf.Bytes()
d.saveBuf.Reset()
}
for len(d.buf) > 0 {
err = d.parseHeaderFieldRepr()
if err == errNeedMore {
// Extra paranoia, making sure saveBuf won't
// get too large. All the varint and string
// reading code earlier should already catch
// overlong things and return ErrStringLength,
// but keep this as a last resort.
const varIntOverhead = 8 // conservative
if d.maxStrLen != 0 && int64(len(d.buf)) > 2*(int64(d.maxStrLen)+varIntOverhead) {
return 0, ErrStringLength
}
d.saveBuf.Write(d.buf)
return len(p), nil
}
d.firstField = false
if err != nil {
break
}
}
return len(p), err
}
// errNeedMore is an internal sentinel error value that means the
// buffer is truncated and we need to read more data before we can
// continue parsing.
var errNeedMore = errors.New("need more data")
type indexType int
const (
indexedTrue indexType = iota
indexedFalse
indexedNever
)
func (v indexType) indexed() bool { return v == indexedTrue }
func (v indexType) sensitive() bool { return v == indexedNever }
// returns errNeedMore if there isn't enough data available.
// any other error is fatal.
// consumes d.buf iff it returns nil.
// precondition: must be called with len(d.buf) > 0
func (d *Decoder) parseHeaderFieldRepr() error {
b := d.buf[0]
switch {
case b&128 != 0:
// Indexed representation.
// High bit set?
// https://httpwg.org/specs/rfc7541.html#rfc.section.6.1
return d.parseFieldIndexed()
case b&192 == 64:
// 6.2.1 Literal Header Field with Incremental Indexing
// 0b10xxxxxx: top two bits are 10
// https://httpwg.org/specs/rfc7541.html#rfc.section.6.2.1
return d.parseFieldLiteral(6, indexedTrue)
case b&240 == 0:
// 6.2.2 Literal Header Field without Indexing
// 0b0000xxxx: top four bits are 0000
// https://httpwg.org/specs/rfc7541.html#rfc.section.6.2.2
return d.parseFieldLiteral(4, indexedFalse)
case b&240 == 16:
// 6.2.3 Literal Header Field never Indexed
// 0b0001xxxx: top four bits are 0001
// https://httpwg.org/specs/rfc7541.html#rfc.section.6.2.3
return d.parseFieldLiteral(4, indexedNever)
case b&224 == 32:
// 6.3 Dynamic Table Size Update
// Top three bits are '001'.
// https://httpwg.org/specs/rfc7541.html#rfc.section.6.3
return d.parseDynamicTableSizeUpdate()
}
return DecodingError{errors.New("invalid encoding")}
}
// (same invariants and behavior as parseHeaderFieldRepr)
func (d *Decoder) parseFieldIndexed() error {
buf := d.buf
idx, buf, err := readVarInt(7, buf)
if err != nil {
return err
}
hf, ok := d.at(idx)
if !ok {
return DecodingError{InvalidIndexError(idx)}
}
d.buf = buf
return d.callEmit(HeaderField{Name: hf.Name, Value: hf.Value})
}
// (same invariants and behavior as parseHeaderFieldRepr)
func (d *Decoder) parseFieldLiteral(n uint8, it indexType) error {
buf := d.buf
nameIdx, buf, err := readVarInt(n, buf)
if err != nil {
return err
}
var hf HeaderField
wantStr := d.emitEnabled || it.indexed()
var undecodedName undecodedString
if nameIdx > 0 {
ihf, ok := d.at(nameIdx)
if !ok {
return DecodingError{InvalidIndexError(nameIdx)}
}
hf.Name = ihf.Name
} else {
undecodedName, buf, err = d.readString(buf)
if err != nil {
return err
}
}
undecodedValue, buf, err := d.readString(buf)
if err != nil {
return err
}
if wantStr {
if nameIdx <= 0 {
hf.Name, err = d.decodeString(undecodedName)
if err != nil {
return err
}
}
hf.Value, err = d.decodeString(undecodedValue)
if err != nil {
return err
}
}
d.buf = buf
if it.indexed() {
d.dynTab.add(hf)
}
hf.Sensitive = it.sensitive()
return d.callEmit(hf)
}
func (d *Decoder) callEmit(hf HeaderField) error {
if d.maxStrLen != 0 {
if len(hf.Name) > d.maxStrLen || len(hf.Value) > d.maxStrLen {
return ErrStringLength
}
}
if d.emitEnabled {
d.emit(hf)
}
return nil
}
// (same invariants and behavior as parseHeaderFieldRepr)
func (d *Decoder) parseDynamicTableSizeUpdate() error {
// RFC 7541, sec 4.2: This dynamic table size update MUST occur at the
// beginning of the first header block following the change to the dynamic table size.
if !d.firstField && d.dynTab.size > 0 {
return DecodingError{errors.New("dynamic table size update MUST occur at the beginning of a header block")}
}
buf := d.buf
size, buf, err := readVarInt(5, buf)
if err != nil {
return err
}
if size > uint64(d.dynTab.allowedMaxSize) {
return DecodingError{errors.New("dynamic table size update too large")}
}
d.dynTab.setMaxSize(uint32(size))
d.buf = buf
return nil
}
var errVarintOverflow = DecodingError{errors.New("varint integer overflow")}
// readVarInt reads an unsigned variable length integer off the
// beginning of p. n is the parameter as described in
// https://httpwg.org/specs/rfc7541.html#rfc.section.5.1.
//
// n must always be between 1 and 8.
//
// The returned remain buffer is either a smaller suffix of p, or err != nil.
// The error is errNeedMore if p doesn't contain a complete integer.
func readVarInt(n byte, p []byte) (i uint64, remain []byte, err error) {
if n < 1 || n > 8 {
panic("bad n")
}
if len(p) == 0 {
return 0, p, errNeedMore
}
i = uint64(p[0])
if n < 8 {
i &= (1 << uint64(n)) - 1
}
if i < (1<<uint64(n))-1 {
return i, p[1:], nil
}
origP := p
p = p[1:]
var m uint64
for len(p) > 0 {
b := p[0]
p = p[1:]
i += uint64(b&127) << m
if b&128 == 0 {
return i, p, nil
}
m += 7
if m >= 63 { // TODO: proper overflow check. making this up.
return 0, origP, errVarintOverflow
}
}
return 0, origP, errNeedMore
}
// readString reads an hpack string from p.
//
// It returns a reference to the encoded string data to permit deferring decode costs
// until after the caller verifies all data is present.
func (d *Decoder) readString(p []byte) (u undecodedString, remain []byte, err error) {
if len(p) == 0 {
return u, p, errNeedMore
}
isHuff := p[0]&128 != 0
strLen, p, err := readVarInt(7, p)
if err != nil {
return u, p, err
}
if d.maxStrLen != 0 && strLen > uint64(d.maxStrLen) {
// Returning an error here means Huffman decoding errors
// for non-indexed strings past the maximum string length
// are ignored, but the server is returning an error anyway
// and because the string is not indexed the error will not
// affect the decoding state.
return u, nil, ErrStringLength
}
if uint64(len(p)) < strLen {
return u, p, errNeedMore
}
u.isHuff = isHuff
u.b = p[:strLen]
return u, p[strLen:], nil
}
type undecodedString struct {
isHuff bool
b []byte
}
func (d *Decoder) decodeString(u undecodedString) (string, error) {
if !u.isHuff {
return string(u.b), nil
}
buf := bufPool.Get().(*bytes.Buffer)
buf.Reset() // don't trust others
var s string
err := huffmanDecode(buf, d.maxStrLen, u.b)
if err == nil {
s = buf.String()
}
buf.Reset() // be nice to GC
bufPool.Put(buf)
return s, err
}

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vendor/golang.org/x/net/http2/hpack/huffman.go generated vendored Normal file
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// Copyright 2014 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 hpack
import (
"bytes"
"errors"
"io"
"sync"
)
var bufPool = sync.Pool{
New: func() interface{} { return new(bytes.Buffer) },
}
// HuffmanDecode decodes the string in v and writes the expanded
// result to w, returning the number of bytes written to w and the
// Write call's return value. At most one Write call is made.
func HuffmanDecode(w io.Writer, v []byte) (int, error) {
buf := bufPool.Get().(*bytes.Buffer)
buf.Reset()
defer bufPool.Put(buf)
if err := huffmanDecode(buf, 0, v); err != nil {
return 0, err
}
return w.Write(buf.Bytes())
}
// HuffmanDecodeToString decodes the string in v.
func HuffmanDecodeToString(v []byte) (string, error) {
buf := bufPool.Get().(*bytes.Buffer)
buf.Reset()
defer bufPool.Put(buf)
if err := huffmanDecode(buf, 0, v); err != nil {
return "", err
}
return buf.String(), nil
}
// ErrInvalidHuffman is returned for errors found decoding
// Huffman-encoded strings.
var ErrInvalidHuffman = errors.New("hpack: invalid Huffman-encoded data")
// huffmanDecode decodes v to buf.
// If maxLen is greater than 0, attempts to write more to buf than
// maxLen bytes will return ErrStringLength.
func huffmanDecode(buf *bytes.Buffer, maxLen int, v []byte) error {
rootHuffmanNode := getRootHuffmanNode()
n := rootHuffmanNode
// cur is the bit buffer that has not been fed into n.
// cbits is the number of low order bits in cur that are valid.
// sbits is the number of bits of the symbol prefix being decoded.
cur, cbits, sbits := uint(0), uint8(0), uint8(0)
for _, b := range v {
cur = cur<<8 | uint(b)
cbits += 8
sbits += 8
for cbits >= 8 {
idx := byte(cur >> (cbits - 8))
n = n.children[idx]
if n == nil {
return ErrInvalidHuffman
}
if n.children == nil {
if maxLen != 0 && buf.Len() == maxLen {
return ErrStringLength
}
buf.WriteByte(n.sym)
cbits -= n.codeLen
n = rootHuffmanNode
sbits = cbits
} else {
cbits -= 8
}
}
}
for cbits > 0 {
n = n.children[byte(cur<<(8-cbits))]
if n == nil {
return ErrInvalidHuffman
}
if n.children != nil || n.codeLen > cbits {
break
}
if maxLen != 0 && buf.Len() == maxLen {
return ErrStringLength
}
buf.WriteByte(n.sym)
cbits -= n.codeLen
n = rootHuffmanNode
sbits = cbits
}
if sbits > 7 {
// Either there was an incomplete symbol, or overlong padding.
// Both are decoding errors per RFC 7541 section 5.2.
return ErrInvalidHuffman
}
if mask := uint(1<<cbits - 1); cur&mask != mask {
// Trailing bits must be a prefix of EOS per RFC 7541 section 5.2.
return ErrInvalidHuffman
}
return nil
}
// incomparable is a zero-width, non-comparable type. Adding it to a struct
// makes that struct also non-comparable, and generally doesn't add
// any size (as long as it's first).
type incomparable [0]func()
type node struct {
_ incomparable
// children is non-nil for internal nodes
children *[256]*node
// The following are only valid if children is nil:
codeLen uint8 // number of bits that led to the output of sym
sym byte // output symbol
}
func newInternalNode() *node {
return &node{children: new([256]*node)}
}
var (
buildRootOnce sync.Once
lazyRootHuffmanNode *node
)
func getRootHuffmanNode() *node {
buildRootOnce.Do(buildRootHuffmanNode)
return lazyRootHuffmanNode
}
func buildRootHuffmanNode() {
if len(huffmanCodes) != 256 {
panic("unexpected size")
}
lazyRootHuffmanNode = newInternalNode()
// allocate a leaf node for each of the 256 symbols
leaves := new([256]node)
for sym, code := range huffmanCodes {
codeLen := huffmanCodeLen[sym]
cur := lazyRootHuffmanNode
for codeLen > 8 {
codeLen -= 8
i := uint8(code >> codeLen)
if cur.children[i] == nil {
cur.children[i] = newInternalNode()
}
cur = cur.children[i]
}
shift := 8 - codeLen
start, end := int(uint8(code<<shift)), int(1<<shift)
leaves[sym].sym = byte(sym)
leaves[sym].codeLen = codeLen
for i := start; i < start+end; i++ {
cur.children[i] = &leaves[sym]
}
}
}
// AppendHuffmanString appends s, as encoded in Huffman codes, to dst
// and returns the extended buffer.
func AppendHuffmanString(dst []byte, s string) []byte {
// This relies on the maximum huffman code length being 30 (See tables.go huffmanCodeLen array)
// So if a uint64 buffer has less than 32 valid bits can always accommodate another huffmanCode.
var (
x uint64 // buffer
n uint // number valid of bits present in x
)
for i := 0; i < len(s); i++ {
c := s[i]
n += uint(huffmanCodeLen[c])
x <<= huffmanCodeLen[c] % 64
x |= uint64(huffmanCodes[c])
if n >= 32 {
n %= 32 // Normally would be -= 32 but %= 32 informs compiler 0 <= n <= 31 for upcoming shift
y := uint32(x >> n) // Compiler doesn't combine memory writes if y isn't uint32
dst = append(dst, byte(y>>24), byte(y>>16), byte(y>>8), byte(y))
}
}
// Add padding bits if necessary
if over := n % 8; over > 0 {
const (
eosCode = 0x3fffffff
eosNBits = 30
eosPadByte = eosCode >> (eosNBits - 8)
)
pad := 8 - over
x = (x << pad) | (eosPadByte >> over)
n += pad // 8 now divides into n exactly
}
// n in (0, 8, 16, 24, 32)
switch n / 8 {
case 0:
return dst
case 1:
return append(dst, byte(x))
case 2:
y := uint16(x)
return append(dst, byte(y>>8), byte(y))
case 3:
y := uint16(x >> 8)
return append(dst, byte(y>>8), byte(y), byte(x))
}
// case 4:
y := uint32(x)
return append(dst, byte(y>>24), byte(y>>16), byte(y>>8), byte(y))
}
// HuffmanEncodeLength returns the number of bytes required to encode
// s in Huffman codes. The result is round up to byte boundary.
func HuffmanEncodeLength(s string) uint64 {
n := uint64(0)
for i := 0; i < len(s); i++ {
n += uint64(huffmanCodeLen[s[i]])
}
return (n + 7) / 8
}

188
vendor/golang.org/x/net/http2/hpack/static_table.go generated vendored Normal file
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// go generate gen.go
// Code generated by the command above; DO NOT EDIT.
package hpack
var staticTable = &headerFieldTable{
evictCount: 0,
byName: map[string]uint64{
":authority": 1,
":method": 3,
":path": 5,
":scheme": 7,
":status": 14,
"accept-charset": 15,
"accept-encoding": 16,
"accept-language": 17,
"accept-ranges": 18,
"accept": 19,
"access-control-allow-origin": 20,
"age": 21,
"allow": 22,
"authorization": 23,
"cache-control": 24,
"content-disposition": 25,
"content-encoding": 26,
"content-language": 27,
"content-length": 28,
"content-location": 29,
"content-range": 30,
"content-type": 31,
"cookie": 32,
"date": 33,
"etag": 34,
"expect": 35,
"expires": 36,
"from": 37,
"host": 38,
"if-match": 39,
"if-modified-since": 40,
"if-none-match": 41,
"if-range": 42,
"if-unmodified-since": 43,
"last-modified": 44,
"link": 45,
"location": 46,
"max-forwards": 47,
"proxy-authenticate": 48,
"proxy-authorization": 49,
"range": 50,
"referer": 51,
"refresh": 52,
"retry-after": 53,
"server": 54,
"set-cookie": 55,
"strict-transport-security": 56,
"transfer-encoding": 57,
"user-agent": 58,
"vary": 59,
"via": 60,
"www-authenticate": 61,
},
byNameValue: map[pairNameValue]uint64{
{name: ":authority", value: ""}: 1,
{name: ":method", value: "GET"}: 2,
{name: ":method", value: "POST"}: 3,
{name: ":path", value: "/"}: 4,
{name: ":path", value: "/index.html"}: 5,
{name: ":scheme", value: "http"}: 6,
{name: ":scheme", value: "https"}: 7,
{name: ":status", value: "200"}: 8,
{name: ":status", value: "204"}: 9,
{name: ":status", value: "206"}: 10,
{name: ":status", value: "304"}: 11,
{name: ":status", value: "400"}: 12,
{name: ":status", value: "404"}: 13,
{name: ":status", value: "500"}: 14,
{name: "accept-charset", value: ""}: 15,
{name: "accept-encoding", value: "gzip, deflate"}: 16,
{name: "accept-language", value: ""}: 17,
{name: "accept-ranges", value: ""}: 18,
{name: "accept", value: ""}: 19,
{name: "access-control-allow-origin", value: ""}: 20,
{name: "age", value: ""}: 21,
{name: "allow", value: ""}: 22,
{name: "authorization", value: ""}: 23,
{name: "cache-control", value: ""}: 24,
{name: "content-disposition", value: ""}: 25,
{name: "content-encoding", value: ""}: 26,
{name: "content-language", value: ""}: 27,
{name: "content-length", value: ""}: 28,
{name: "content-location", value: ""}: 29,
{name: "content-range", value: ""}: 30,
{name: "content-type", value: ""}: 31,
{name: "cookie", value: ""}: 32,
{name: "date", value: ""}: 33,
{name: "etag", value: ""}: 34,
{name: "expect", value: ""}: 35,
{name: "expires", value: ""}: 36,
{name: "from", value: ""}: 37,
{name: "host", value: ""}: 38,
{name: "if-match", value: ""}: 39,
{name: "if-modified-since", value: ""}: 40,
{name: "if-none-match", value: ""}: 41,
{name: "if-range", value: ""}: 42,
{name: "if-unmodified-since", value: ""}: 43,
{name: "last-modified", value: ""}: 44,
{name: "link", value: ""}: 45,
{name: "location", value: ""}: 46,
{name: "max-forwards", value: ""}: 47,
{name: "proxy-authenticate", value: ""}: 48,
{name: "proxy-authorization", value: ""}: 49,
{name: "range", value: ""}: 50,
{name: "referer", value: ""}: 51,
{name: "refresh", value: ""}: 52,
{name: "retry-after", value: ""}: 53,
{name: "server", value: ""}: 54,
{name: "set-cookie", value: ""}: 55,
{name: "strict-transport-security", value: ""}: 56,
{name: "transfer-encoding", value: ""}: 57,
{name: "user-agent", value: ""}: 58,
{name: "vary", value: ""}: 59,
{name: "via", value: ""}: 60,
{name: "www-authenticate", value: ""}: 61,
},
ents: []HeaderField{
{Name: ":authority", Value: "", Sensitive: false},
{Name: ":method", Value: "GET", Sensitive: false},
{Name: ":method", Value: "POST", Sensitive: false},
{Name: ":path", Value: "/", Sensitive: false},
{Name: ":path", Value: "/index.html", Sensitive: false},
{Name: ":scheme", Value: "http", Sensitive: false},
{Name: ":scheme", Value: "https", Sensitive: false},
{Name: ":status", Value: "200", Sensitive: false},
{Name: ":status", Value: "204", Sensitive: false},
{Name: ":status", Value: "206", Sensitive: false},
{Name: ":status", Value: "304", Sensitive: false},
{Name: ":status", Value: "400", Sensitive: false},
{Name: ":status", Value: "404", Sensitive: false},
{Name: ":status", Value: "500", Sensitive: false},
{Name: "accept-charset", Value: "", Sensitive: false},
{Name: "accept-encoding", Value: "gzip, deflate", Sensitive: false},
{Name: "accept-language", Value: "", Sensitive: false},
{Name: "accept-ranges", Value: "", Sensitive: false},
{Name: "accept", Value: "", Sensitive: false},
{Name: "access-control-allow-origin", Value: "", Sensitive: false},
{Name: "age", Value: "", Sensitive: false},
{Name: "allow", Value: "", Sensitive: false},
{Name: "authorization", Value: "", Sensitive: false},
{Name: "cache-control", Value: "", Sensitive: false},
{Name: "content-disposition", Value: "", Sensitive: false},
{Name: "content-encoding", Value: "", Sensitive: false},
{Name: "content-language", Value: "", Sensitive: false},
{Name: "content-length", Value: "", Sensitive: false},
{Name: "content-location", Value: "", Sensitive: false},
{Name: "content-range", Value: "", Sensitive: false},
{Name: "content-type", Value: "", Sensitive: false},
{Name: "cookie", Value: "", Sensitive: false},
{Name: "date", Value: "", Sensitive: false},
{Name: "etag", Value: "", Sensitive: false},
{Name: "expect", Value: "", Sensitive: false},
{Name: "expires", Value: "", Sensitive: false},
{Name: "from", Value: "", Sensitive: false},
{Name: "host", Value: "", Sensitive: false},
{Name: "if-match", Value: "", Sensitive: false},
{Name: "if-modified-since", Value: "", Sensitive: false},
{Name: "if-none-match", Value: "", Sensitive: false},
{Name: "if-range", Value: "", Sensitive: false},
{Name: "if-unmodified-since", Value: "", Sensitive: false},
{Name: "last-modified", Value: "", Sensitive: false},
{Name: "link", Value: "", Sensitive: false},
{Name: "location", Value: "", Sensitive: false},
{Name: "max-forwards", Value: "", Sensitive: false},
{Name: "proxy-authenticate", Value: "", Sensitive: false},
{Name: "proxy-authorization", Value: "", Sensitive: false},
{Name: "range", Value: "", Sensitive: false},
{Name: "referer", Value: "", Sensitive: false},
{Name: "refresh", Value: "", Sensitive: false},
{Name: "retry-after", Value: "", Sensitive: false},
{Name: "server", Value: "", Sensitive: false},
{Name: "set-cookie", Value: "", Sensitive: false},
{Name: "strict-transport-security", Value: "", Sensitive: false},
{Name: "transfer-encoding", Value: "", Sensitive: false},
{Name: "user-agent", Value: "", Sensitive: false},
{Name: "vary", Value: "", Sensitive: false},
{Name: "via", Value: "", Sensitive: false},
{Name: "www-authenticate", Value: "", Sensitive: false},
},
}

403
vendor/golang.org/x/net/http2/hpack/tables.go generated vendored Normal file
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@ -0,0 +1,403 @@
// Copyright 2014 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 hpack
import (
"fmt"
)
// headerFieldTable implements a list of HeaderFields.
// This is used to implement the static and dynamic tables.
type headerFieldTable struct {
// For static tables, entries are never evicted.
//
// For dynamic tables, entries are evicted from ents[0] and added to the end.
// Each entry has a unique id that starts at one and increments for each
// entry that is added. This unique id is stable across evictions, meaning
// it can be used as a pointer to a specific entry. As in hpack, unique ids
// are 1-based. The unique id for ents[k] is k + evictCount + 1.
//
// Zero is not a valid unique id.
//
// evictCount should not overflow in any remotely practical situation. In
// practice, we will have one dynamic table per HTTP/2 connection. If we
// assume a very powerful server that handles 1M QPS per connection and each
// request adds (then evicts) 100 entries from the table, it would still take
// 2M years for evictCount to overflow.
ents []HeaderField
evictCount uint64
// byName maps a HeaderField name to the unique id of the newest entry with
// the same name. See above for a definition of "unique id".
byName map[string]uint64
// byNameValue maps a HeaderField name/value pair to the unique id of the newest
// entry with the same name and value. See above for a definition of "unique id".
byNameValue map[pairNameValue]uint64
}
type pairNameValue struct {
name, value string
}
func (t *headerFieldTable) init() {
t.byName = make(map[string]uint64)
t.byNameValue = make(map[pairNameValue]uint64)
}
// len reports the number of entries in the table.
func (t *headerFieldTable) len() int {
return len(t.ents)
}
// addEntry adds a new entry.
func (t *headerFieldTable) addEntry(f HeaderField) {
id := uint64(t.len()) + t.evictCount + 1
t.byName[f.Name] = id
t.byNameValue[pairNameValue{f.Name, f.Value}] = id
t.ents = append(t.ents, f)
}
// evictOldest evicts the n oldest entries in the table.
func (t *headerFieldTable) evictOldest(n int) {
if n > t.len() {
panic(fmt.Sprintf("evictOldest(%v) on table with %v entries", n, t.len()))
}
for k := 0; k < n; k++ {
f := t.ents[k]
id := t.evictCount + uint64(k) + 1
if t.byName[f.Name] == id {
delete(t.byName, f.Name)
}
if p := (pairNameValue{f.Name, f.Value}); t.byNameValue[p] == id {
delete(t.byNameValue, p)
}
}
copy(t.ents, t.ents[n:])
for k := t.len() - n; k < t.len(); k++ {
t.ents[k] = HeaderField{} // so strings can be garbage collected
}
t.ents = t.ents[:t.len()-n]
if t.evictCount+uint64(n) < t.evictCount {
panic("evictCount overflow")
}
t.evictCount += uint64(n)
}
// search finds f in the table. If there is no match, i is 0.
// If both name and value match, i is the matched index and nameValueMatch
// becomes true. If only name matches, i points to that index and
// nameValueMatch becomes false.
//
// The returned index is a 1-based HPACK index. For dynamic tables, HPACK says
// that index 1 should be the newest entry, but t.ents[0] is the oldest entry,
// meaning t.ents is reversed for dynamic tables. Hence, when t is a dynamic
// table, the return value i actually refers to the entry t.ents[t.len()-i].
//
// All tables are assumed to be a dynamic tables except for the global staticTable.
//
// See Section 2.3.3.
func (t *headerFieldTable) search(f HeaderField) (i uint64, nameValueMatch bool) {
if !f.Sensitive {
if id := t.byNameValue[pairNameValue{f.Name, f.Value}]; id != 0 {
return t.idToIndex(id), true
}
}
if id := t.byName[f.Name]; id != 0 {
return t.idToIndex(id), false
}
return 0, false
}
// idToIndex converts a unique id to an HPACK index.
// See Section 2.3.3.
func (t *headerFieldTable) idToIndex(id uint64) uint64 {
if id <= t.evictCount {
panic(fmt.Sprintf("id (%v) <= evictCount (%v)", id, t.evictCount))
}
k := id - t.evictCount - 1 // convert id to an index t.ents[k]
if t != staticTable {
return uint64(t.len()) - k // dynamic table
}
return k + 1
}
var huffmanCodes = [256]uint32{
0x1ff8,
0x7fffd8,
0xfffffe2,
0xfffffe3,
0xfffffe4,
0xfffffe5,
0xfffffe6,
0xfffffe7,
0xfffffe8,
0xffffea,
0x3ffffffc,
0xfffffe9,
0xfffffea,
0x3ffffffd,
0xfffffeb,
0xfffffec,
0xfffffed,
0xfffffee,
0xfffffef,
0xffffff0,
0xffffff1,
0xffffff2,
0x3ffffffe,
0xffffff3,
0xffffff4,
0xffffff5,
0xffffff6,
0xffffff7,
0xffffff8,
0xffffff9,
0xffffffa,
0xffffffb,
0x14,
0x3f8,
0x3f9,
0xffa,
0x1ff9,
0x15,
0xf8,
0x7fa,
0x3fa,
0x3fb,
0xf9,
0x7fb,
0xfa,
0x16,
0x17,
0x18,
0x0,
0x1,
0x2,
0x19,
0x1a,
0x1b,
0x1c,
0x1d,
0x1e,
0x1f,
0x5c,
0xfb,
0x7ffc,
0x20,
0xffb,
0x3fc,
0x1ffa,
0x21,
0x5d,
0x5e,
0x5f,
0x60,
0x61,
0x62,
0x63,
0x64,
0x65,
0x66,
0x67,
0x68,
0x69,
0x6a,
0x6b,
0x6c,
0x6d,
0x6e,
0x6f,
0x70,
0x71,
0x72,
0xfc,
0x73,
0xfd,
0x1ffb,
0x7fff0,
0x1ffc,
0x3ffc,
0x22,
0x7ffd,
0x3,
0x23,
0x4,
0x24,
0x5,
0x25,
0x26,
0x27,
0x6,
0x74,
0x75,
0x28,
0x29,
0x2a,
0x7,
0x2b,
0x76,
0x2c,
0x8,
0x9,
0x2d,
0x77,
0x78,
0x79,
0x7a,
0x7b,
0x7ffe,
0x7fc,
0x3ffd,
0x1ffd,
0xffffffc,
0xfffe6,
0x3fffd2,
0xfffe7,
0xfffe8,
0x3fffd3,
0x3fffd4,
0x3fffd5,
0x7fffd9,
0x3fffd6,
0x7fffda,
0x7fffdb,
0x7fffdc,
0x7fffdd,
0x7fffde,
0xffffeb,
0x7fffdf,
0xffffec,
0xffffed,
0x3fffd7,
0x7fffe0,
0xffffee,
0x7fffe1,
0x7fffe2,
0x7fffe3,
0x7fffe4,
0x1fffdc,
0x3fffd8,
0x7fffe5,
0x3fffd9,
0x7fffe6,
0x7fffe7,
0xffffef,
0x3fffda,
0x1fffdd,
0xfffe9,
0x3fffdb,
0x3fffdc,
0x7fffe8,
0x7fffe9,
0x1fffde,
0x7fffea,
0x3fffdd,
0x3fffde,
0xfffff0,
0x1fffdf,
0x3fffdf,
0x7fffeb,
0x7fffec,
0x1fffe0,
0x1fffe1,
0x3fffe0,
0x1fffe2,
0x7fffed,
0x3fffe1,
0x7fffee,
0x7fffef,
0xfffea,
0x3fffe2,
0x3fffe3,
0x3fffe4,
0x7ffff0,
0x3fffe5,
0x3fffe6,
0x7ffff1,
0x3ffffe0,
0x3ffffe1,
0xfffeb,
0x7fff1,
0x3fffe7,
0x7ffff2,
0x3fffe8,
0x1ffffec,
0x3ffffe2,
0x3ffffe3,
0x3ffffe4,
0x7ffffde,
0x7ffffdf,
0x3ffffe5,
0xfffff1,
0x1ffffed,
0x7fff2,
0x1fffe3,
0x3ffffe6,
0x7ffffe0,
0x7ffffe1,
0x3ffffe7,
0x7ffffe2,
0xfffff2,
0x1fffe4,
0x1fffe5,
0x3ffffe8,
0x3ffffe9,
0xffffffd,
0x7ffffe3,
0x7ffffe4,
0x7ffffe5,
0xfffec,
0xfffff3,
0xfffed,
0x1fffe6,
0x3fffe9,
0x1fffe7,
0x1fffe8,
0x7ffff3,
0x3fffea,
0x3fffeb,
0x1ffffee,
0x1ffffef,
0xfffff4,
0xfffff5,
0x3ffffea,
0x7ffff4,
0x3ffffeb,
0x7ffffe6,
0x3ffffec,
0x3ffffed,
0x7ffffe7,
0x7ffffe8,
0x7ffffe9,
0x7ffffea,
0x7ffffeb,
0xffffffe,
0x7ffffec,
0x7ffffed,
0x7ffffee,
0x7ffffef,
0x7fffff0,
0x3ffffee,
}
var huffmanCodeLen = [256]uint8{
13, 23, 28, 28, 28, 28, 28, 28, 28, 24, 30, 28, 28, 30, 28, 28,
28, 28, 28, 28, 28, 28, 30, 28, 28, 28, 28, 28, 28, 28, 28, 28,
6, 10, 10, 12, 13, 6, 8, 11, 10, 10, 8, 11, 8, 6, 6, 6,
5, 5, 5, 6, 6, 6, 6, 6, 6, 6, 7, 8, 15, 6, 12, 10,
13, 6, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
7, 7, 7, 7, 7, 7, 7, 7, 8, 7, 8, 13, 19, 13, 14, 6,
15, 5, 6, 5, 6, 5, 6, 6, 6, 5, 7, 7, 6, 6, 6, 5,
6, 7, 6, 5, 5, 6, 7, 7, 7, 7, 7, 15, 11, 14, 13, 28,
20, 22, 20, 20, 22, 22, 22, 23, 22, 23, 23, 23, 23, 23, 24, 23,
24, 24, 22, 23, 24, 23, 23, 23, 23, 21, 22, 23, 22, 23, 23, 24,
22, 21, 20, 22, 22, 23, 23, 21, 23, 22, 22, 24, 21, 22, 23, 23,
21, 21, 22, 21, 23, 22, 23, 23, 20, 22, 22, 22, 23, 22, 22, 23,
26, 26, 20, 19, 22, 23, 22, 25, 26, 26, 26, 27, 27, 26, 24, 25,
19, 21, 26, 27, 27, 26, 27, 24, 21, 21, 26, 26, 28, 27, 27, 27,
20, 24, 20, 21, 22, 21, 21, 23, 22, 22, 25, 25, 24, 24, 26, 23,
26, 27, 26, 26, 27, 27, 27, 27, 27, 28, 27, 27, 27, 27, 27, 26,
}