3
0
mirror of https://github.com/42wim/matterbridge.git synced 2024-12-25 12:42:37 +01:00
matterbridge/vendor/github.com/Rhymen/go-whatsapp/binary/decoder.go

389 lines
7.2 KiB
Go
Raw Normal View History

2019-02-21 20:28:13 +01:00
package binary
import (
"fmt"
2019-05-30 12:20:56 +02:00
"github.com/Rhymen/go-whatsapp/binary/token"
2019-02-21 20:28:13 +01:00
"io"
"strconv"
)
type binaryDecoder struct {
data []byte
index int
}
func NewDecoder(data []byte) *binaryDecoder {
return &binaryDecoder{data, 0}
}
func (r *binaryDecoder) checkEOS(length int) error {
if r.index+length > len(r.data) {
return io.EOF
}
return nil
}
func (r *binaryDecoder) readByte() (byte, error) {
if err := r.checkEOS(1); err != nil {
return 0, err
}
b := r.data[r.index]
r.index++
return b, nil
}
func (r *binaryDecoder) readIntN(n int, littleEndian bool) (int, error) {
if err := r.checkEOS(n); err != nil {
return 0, err
}
var ret int
for i := 0; i < n; i++ {
var curShift int
if littleEndian {
curShift = i
} else {
curShift = n - i - 1
}
ret |= int(r.data[r.index+i]) << uint(curShift*8)
}
r.index += n
return ret, nil
}
func (r *binaryDecoder) readInt8(littleEndian bool) (int, error) {
return r.readIntN(1, littleEndian)
}
func (r *binaryDecoder) readInt16(littleEndian bool) (int, error) {
return r.readIntN(2, littleEndian)
}
func (r *binaryDecoder) readInt20() (int, error) {
if err := r.checkEOS(3); err != nil {
return 0, err
}
ret := ((int(r.data[r.index]) & 15) << 16) + (int(r.data[r.index+1]) << 8) + int(r.data[r.index+2])
r.index += 3
return ret, nil
}
func (r *binaryDecoder) readInt32(littleEndian bool) (int, error) {
return r.readIntN(4, littleEndian)
}
func (r *binaryDecoder) readInt64(littleEndian bool) (int, error) {
return r.readIntN(8, littleEndian)
}
func (r *binaryDecoder) readPacked8(tag int) (string, error) {
startByte, err := r.readByte()
if err != nil {
return "", err
}
ret := ""
for i := 0; i < int(startByte&127); i++ {
currByte, err := r.readByte()
if err != nil {
return "", err
}
lower, err := unpackByte(tag, currByte&0xF0>>4)
if err != nil {
return "", err
}
upper, err := unpackByte(tag, currByte&0x0F)
if err != nil {
return "", err
}
ret += lower + upper
}
if startByte>>7 != 0 {
ret = ret[:len(ret)-1]
}
return ret, nil
}
func unpackByte(tag int, value byte) (string, error) {
switch tag {
case token.NIBBLE_8:
return unpackNibble(value)
case token.HEX_8:
return unpackHex(value)
default:
return "", fmt.Errorf("unpackByte with unknown tag %d", tag)
}
}
func unpackNibble(value byte) (string, error) {
switch {
case value < 0 || value > 15:
return "", fmt.Errorf("unpackNibble with value %d", value)
case value == 10:
return "-", nil
case value == 11:
return ".", nil
case value == 15:
return "\x00", nil
default:
return strconv.Itoa(int(value)), nil
}
}
func unpackHex(value byte) (string, error) {
switch {
case value < 0 || value > 15:
return "", fmt.Errorf("unpackHex with value %d", value)
case value < 10:
return strconv.Itoa(int(value)), nil
default:
return string('A' + value - 10), nil
}
}
func (r *binaryDecoder) readListSize(tag int) (int, error) {
switch tag {
case token.LIST_EMPTY:
return 0, nil
case token.LIST_8:
return r.readInt8(false)
case token.LIST_16:
return r.readInt16(false)
default:
return 0, fmt.Errorf("readListSize with unknown tag %d at position %d", tag, r.index)
}
}
func (r *binaryDecoder) readString(tag int) (string, error) {
switch {
case tag >= 3 && tag <= len(token.SingleByteTokens):
tok, err := token.GetSingleToken(tag)
if err != nil {
return "", err
}
if tok == "s.whatsapp.net" {
tok = "c.us"
}
return tok, nil
case tag == token.DICTIONARY_0 || tag == token.DICTIONARY_1 || tag == token.DICTIONARY_2 || tag == token.DICTIONARY_3:
i, err := r.readInt8(false)
if err != nil {
return "", err
}
return token.GetDoubleToken(tag-token.DICTIONARY_0, i)
case tag == token.LIST_EMPTY:
return "", nil
case tag == token.BINARY_8:
length, err := r.readInt8(false)
if err != nil {
return "", err
}
return r.readStringFromChars(length)
case tag == token.BINARY_20:
length, err := r.readInt20()
if err != nil {
return "", err
}
return r.readStringFromChars(length)
case tag == token.BINARY_32:
length, err := r.readInt32(false)
if err != nil {
return "", err
}
return r.readStringFromChars(length)
case tag == token.JID_PAIR:
b, err := r.readByte()
if err != nil {
return "", err
}
i, err := r.readString(int(b))
if err != nil {
return "", err
}
b, err = r.readByte()
if err != nil {
return "", err
}
j, err := r.readString(int(b))
if err != nil {
return "", err
}
if i == "" || j == "" {
return "", fmt.Errorf("invalid jid pair: %s - %s", i, j)
}
return i + "@" + j, nil
case tag == token.NIBBLE_8 || tag == token.HEX_8:
return r.readPacked8(tag)
default:
return "", fmt.Errorf("invalid string with tag %d", tag)
}
}
func (r *binaryDecoder) readStringFromChars(length int) (string, error) {
if err := r.checkEOS(length); err != nil {
return "", err
}
ret := r.data[r.index : r.index+length]
r.index += length
return string(ret), nil
}
func (r *binaryDecoder) readAttributes(n int) (map[string]string, error) {
if n == 0 {
return nil, nil
}
ret := make(map[string]string)
for i := 0; i < n; i++ {
idx, err := r.readInt8(false)
if err != nil {
return nil, err
}
index, err := r.readString(idx)
if err != nil {
return nil, err
}
idx, err = r.readInt8(false)
if err != nil {
return nil, err
}
ret[index], err = r.readString(idx)
if err != nil {
return nil, err
}
}
return ret, nil
}
func (r *binaryDecoder) readList(tag int) ([]Node, error) {
size, err := r.readListSize(tag)
if err != nil {
return nil, err
}
ret := make([]Node, size)
for i := 0; i < size; i++ {
n, err := r.ReadNode()
if err != nil {
return nil, err
}
ret[i] = *n
}
return ret, nil
}
func (r *binaryDecoder) ReadNode() (*Node, error) {
ret := &Node{}
size, err := r.readInt8(false)
if err != nil {
return nil, err
}
listSize, err := r.readListSize(size)
if err != nil {
return nil, err
}
descrTag, err := r.readInt8(false)
if descrTag == token.STREAM_END {
return nil, fmt.Errorf("unexpected stream end")
}
ret.Description, err = r.readString(descrTag)
if err != nil {
return nil, err
}
if listSize == 0 || ret.Description == "" {
return nil, fmt.Errorf("invalid Node")
}
ret.Attributes, err = r.readAttributes((listSize - 1) >> 1)
if err != nil {
return nil, err
}
if listSize%2 == 1 {
return ret, nil
}
tag, err := r.readInt8(false)
if err != nil {
return nil, err
}
switch tag {
case token.LIST_EMPTY, token.LIST_8, token.LIST_16:
ret.Content, err = r.readList(tag)
case token.BINARY_8:
size, err = r.readInt8(false)
if err != nil {
return nil, err
}
ret.Content, err = r.readBytes(size)
case token.BINARY_20:
size, err = r.readInt20()
if err != nil {
return nil, err
}
ret.Content, err = r.readBytes(size)
case token.BINARY_32:
size, err = r.readInt32(false)
if err != nil {
return nil, err
}
ret.Content, err = r.readBytes(size)
default:
ret.Content, err = r.readString(tag)
}
if err != nil {
return nil, err
}
return ret, nil
}
func (r *binaryDecoder) readBytes(n int) ([]byte, error) {
ret := make([]byte, n)
var err error
for i := range ret {
ret[i], err = r.readByte()
if err != nil {
return nil, err
}
}
return ret, nil
}