mirror of
https://github.com/cwinfo/matterbridge.git
synced 2024-11-27 07:41:36 +00:00
32 lines
1001 B
Go
32 lines
1001 B
Go
|
// Copyright (c) 2021 Tulir Asokan
|
||
|
|
//
|
||
|
|
// This Source Code Form is subject to the terms of the Mozilla Public
|
||
|
|
// License, v. 2.0. If a copy of the MPL was not distributed with this
|
||
|
|
// file, You can obtain one at http://mozilla.org/MPL/2.0/.
|
||
|
|
|
||
|
|
package binary
|
||
|
|
|
||
|
|
import (
|
||
|
|
"bytes"
|
||
|
|
"compress/zlib"
|
||
|
|
"fmt"
|
||
|
|
"io"
|
||
|
|
)
|
||
|
|
|
||
|
|
// Unpack unpacks the given decrypted data from the WhatsApp web API.
|
||
|
|
//
|
||
|
|
// It checks the first byte to decide whether to uncompress the data with zlib or just return as-is
|
||
|
|
// (without the first byte). There's currently no corresponding Pack function because Marshal
|
||
|
|
// already returns the data with a leading zero (i.e. not compressed).
|
||
|
|
func Unpack(data []byte) ([]byte, error) {
|
||
|
|
dataType, data := data[0], data[1:]
|
||
|
|
if 2&dataType > 0 {
|
||
|
|
if decompressor, err := zlib.NewReader(bytes.NewReader(data)); err != nil {
|
||
|
|
return nil, fmt.Errorf("failed to create zlib reader: %w", err)
|
||
|
|
} else if data, err = io.ReadAll(decompressor); err != nil {
|
||
|
|
return nil, err
|
||
|
|
}
|
||
|
|
}
|
||
|
|
return data, nil
|
||
|
|
}
|