1
1
mirror of https://github.com/OpenDiablo2/OpenDiablo2 synced 2024-11-18 18:36:12 -05:00
OpenDiablo2/d2common/d2fileformats/d2mpq/mpq.go
2020-08-04 22:52:54 -04:00

386 lines
10 KiB
Go

package d2mpq
import (
"bufio"
"encoding/binary"
"errors"
"io/ioutil"
"log"
"os"
"path"
"path/filepath"
"runtime"
"strings"
"github.com/OpenDiablo2/OpenDiablo2/d2common/d2interface"
)
var _ d2interface.Archive = &MPQ{} // Static check to confirm struct conforms to interface
// MPQ represents an MPQ archive
type MPQ struct {
filePath string
file *os.File
hashEntryMap HashEntryMap
blockTableEntries []BlockTableEntry
data Data
}
// Data Represents a MPQ file
type Data struct {
Magic [4]byte
HeaderSize uint32
ArchiveSize uint32
FormatVersion uint16
BlockSize uint16
HashTableOffset uint32
BlockTableOffset uint32
HashTableEntries uint32
BlockTableEntries uint32
}
// HashTableEntry represents a hashed file entry in the MPQ file
type HashTableEntry struct { // 16 bytes
NamePartA uint32
NamePartB uint32
Locale uint16
Platform uint16
BlockIndex uint32
}
// PatchInfo represents patch info for the MPQ.
type PatchInfo struct {
Length uint32 // Length of patch info header, in bytes
Flags uint32 // Flags. 0x80000000 = MD5 (?)
DataSize uint32 // Uncompressed size of the patch file
Md5 [16]byte // MD5 of the entire patch file after decompression
}
// FileFlag represents flags for a file record in the MPQ archive
type FileFlag uint32
const (
// FileImplode - File is compressed using PKWARE Data compression library
FileImplode FileFlag = 0x00000100
// FileCompress - File is compressed using combination of compression methods
FileCompress FileFlag = 0x00000200
// FileEncrypted - The file is encrypted
FileEncrypted FileFlag = 0x00010000
// FileFixKey - The decryption key for the file is altered according to the position of the file in the archive
FileFixKey FileFlag = 0x00020000
// FilePatchFile - The file contains incremental patch for an existing file in base MPQ
FilePatchFile FileFlag = 0x00100000
// FileSingleUnit - Instead of being divided to 0x1000-bytes blocks, the file is stored as single unit
FileSingleUnit FileFlag = 0x01000000
// FileDeleteMarker - File is a deletion marker, indicating that the file no longer exists. This is used to allow patch
// archives to delete files present in lower-priority archives in the search chain. The file usually
// has length of 0 or 1 byte and its name is a hash
FileDeleteMarker FileFlag = 0x02000000
// FileSectorCrc - File has checksums for each sector. Ignored if file is not compressed or imploded.
FileSectorCrc FileFlag = 0x04000000
// FileExists - Set if file exists, reset when the file was deleted
FileExists FileFlag = 0x80000000
)
// BlockTableEntry represents an entry in the block table
type BlockTableEntry struct { // 16 bytes
FilePosition uint32
CompressedFileSize uint32
UncompressedFileSize uint32
Flags FileFlag
// Local Stuff...
FileName string
EncryptionSeed uint32
}
// HasFlag returns true if the specified flag is present
func (v BlockTableEntry) HasFlag(flag FileFlag) bool {
return (v.Flags & flag) != 0
}
// Load loads an MPQ file and returns a MPQ structure
func Load(fileName string) (d2interface.Archive, error) {
result := &MPQ{filePath: fileName}
var err error
if runtime.GOOS == "linux" {
result.file, err = openIgnoreCase(fileName)
} else {
result.file, err = os.Open(fileName) //nolint:gosec Will fix later
}
if err != nil {
return nil, err
}
if err := result.readHeader(); err != nil {
return nil, err
}
return result, nil
}
func openIgnoreCase(mpqPath string) (*os.File, error) {
// First see if file exists with specified case
mpqFile, err := os.Open(mpqPath) //nolint:gosec Will fix later
if err == nil {
return mpqFile, err
}
mpqName := filepath.Base(mpqPath)
mpqDir := filepath.Dir(mpqPath)
files, err := ioutil.ReadDir(mpqDir)
if err != nil {
return nil, err
}
for _, file := range files {
if strings.EqualFold(file.Name(), mpqName) {
mpqName = file.Name()
break
}
}
file, err := os.Open(path.Join(mpqDir, mpqName)) //nolint:gosec Will fix later
return file, err
}
func (v *MPQ) readHeader() error {
err := binary.Read(v.file, binary.LittleEndian, &v.data)
if err != nil {
return err
}
if string(v.data.Magic[:]) != "MPQ\x1A" {
return errors.New("invalid mpq header")
}
v.loadHashTable()
v.loadBlockTable()
return nil
}
func (v *MPQ) loadHashTable() {
_, err := v.file.Seek(int64(v.data.HashTableOffset), 0)
if err != nil {
log.Panic(err)
}
hashData := make([]uint32, v.data.HashTableEntries*4) //nolint:gomnd Decryption magic
hash := make([]byte, 4)
for i := range hashData {
_, _ = v.file.Read(hash)
hashData[i] = binary.LittleEndian.Uint32(hash)
}
decrypt(hashData, hashString("(hash table)", 3))
for i := uint32(0); i < v.data.HashTableEntries; i++ {
v.hashEntryMap.Insert(&HashTableEntry{
NamePartA: hashData[i*4],
NamePartB: hashData[(i*4)+1],
//nolint:godox // TODO: Verify that we're grabbing the right high/lo word for the vars below
Locale: uint16(hashData[(i*4)+2] >> 16), //nolint:gomnd binary data
Platform: uint16(hashData[(i*4)+2] & 0xFFFF), //nolint:gomnd binary data
BlockIndex: hashData[(i*4)+3],
})
}
}
func (v *MPQ) loadBlockTable() {
_, err := v.file.Seek(int64(v.data.BlockTableOffset), 0)
if err != nil {
log.Panic(err)
}
blockData := make([]uint32, v.data.BlockTableEntries*4) //nolint:gomnd binary data
hash := make([]byte, 4)
for i := range blockData {
_, _ = v.file.Read(hash[:]) //nolint:errcheck Will fix later
blockData[i] = binary.LittleEndian.Uint32(hash)
}
decrypt(blockData, hashString("(block table)", 3))
for i := uint32(0); i < v.data.BlockTableEntries; i++ {
v.blockTableEntries = append(v.blockTableEntries, BlockTableEntry{
FilePosition: blockData[(i * 4)],
CompressedFileSize: blockData[(i*4)+1],
UncompressedFileSize: blockData[(i*4)+2],
Flags: FileFlag(blockData[(i*4)+3]),
})
}
}
func decrypt(data []uint32, seed uint32) {
seed2 := uint32(0xeeeeeeee) //nolint:gomnd Decryption magic
for i := 0; i < len(data); i++ {
seed2 += cryptoLookup(0x400 + (seed & 0xff)) //nolint:gomnd Decryption magic
result := data[i]
result ^= seed + seed2
seed = ((^seed << 21) + 0x11111111) | (seed >> 11)
seed2 = result + seed2 + (seed2 << 5) + 3 //nolint:gomnd Decryption magic
data[i] = result
}
}
func decryptBytes(data []byte, seed uint32) {
seed2 := uint32(0xEEEEEEEE) //nolint:gomnd Decryption magic
for i := 0; i < len(data)-3; i += 4 {
seed2 += cryptoLookup(0x400 + (seed & 0xFF)) //nolint:gomnd Decryption magic
result := binary.LittleEndian.Uint32(data[i : i+4])
result ^= seed + seed2
seed = ((^seed << 21) + 0x11111111) | (seed >> 11)
seed2 = result + seed2 + (seed2 << 5) + 3 //nolint:gomnd Decryption magic
data[i+0] = uint8(result & 0xff) //nolint:gomnd Decryption magic
data[i+1] = uint8((result >> 8) & 0xff) //nolint:gomnd Decryption magic
data[i+2] = uint8((result >> 16) & 0xff) //nolint:gomnd Decryption magic
data[i+3] = uint8((result >> 24) & 0xff) //nolint:gomnd Decryption magic
}
}
func hashString(key string, hashType uint32) uint32 {
seed1 := uint32(0x7FED7FED) //nolint:gomnd Decryption magic
seed2 := uint32(0xEEEEEEEE) //nolint:gomnd Decryption magic
/* prepare seeds. */
for _, char := range strings.ToUpper(key) {
seed1 = cryptoLookup((hashType*0x100)+uint32(char)) ^ (seed1 + seed2)
seed2 = uint32(char) + seed1 + seed2 + (seed2 << 5) + 3 //nolint:gomnd Decryption magic
}
return seed1
}
// GetFileBlockData gets a block table entry
func (v *MPQ) getFileBlockData(fileName string) (BlockTableEntry, error) {
fileEntry, found := v.hashEntryMap.Find(fileName)
if !found || fileEntry.BlockIndex >= uint32(len(v.blockTableEntries)) {
return BlockTableEntry{}, errors.New("file not found")
}
return v.blockTableEntries[fileEntry.BlockIndex], nil
}
// Close closes the MPQ file
func (v *MPQ) Close() {
err := v.file.Close()
if err != nil {
log.Panic(err)
}
}
// FileExists checks the mpq to see if the file exists
func (v *MPQ) FileExists(fileName string) bool {
return v.hashEntryMap.Contains(fileName)
}
// ReadFile reads a file from the MPQ and returns a memory stream
func (v *MPQ) ReadFile(fileName string) ([]byte, error) {
fileBlockData, err := v.getFileBlockData(fileName)
if err != nil {
return []byte{}, err
}
fileBlockData.FileName = strings.ToLower(fileName)
fileBlockData.calculateEncryptionSeed()
mpqStream, err := CreateStream(v, fileBlockData, fileName)
if err != nil {
return []byte{}, err
}
buffer := make([]byte, fileBlockData.UncompressedFileSize)
mpqStream.Read(buffer, 0, fileBlockData.UncompressedFileSize)
return buffer, nil
}
// ReadFileStream reads the mpq file data and returns a stream
func (v *MPQ) ReadFileStream(fileName string) (d2interface.ArchiveDataStream, error) {
fileBlockData, err := v.getFileBlockData(fileName)
if err != nil {
return nil, err
}
fileBlockData.FileName = strings.ToLower(fileName)
fileBlockData.calculateEncryptionSeed()
mpqStream, err := CreateStream(v, fileBlockData, fileName)
if err != nil {
return nil, err
}
return &MpqDataStream{stream: mpqStream}, nil
}
// ReadTextFile reads a file and returns it as a string
func (v *MPQ) ReadTextFile(fileName string) (string, error) {
data, err := v.ReadFile(fileName)
if err != nil {
return "", err
}
return string(data), nil
}
func (v *BlockTableEntry) calculateEncryptionSeed() {
fileName := path.Base(v.FileName)
v.EncryptionSeed = hashString(fileName, 3)
if !v.HasFlag(FileFixKey) {
return
}
v.EncryptionSeed = (v.EncryptionSeed + v.FilePosition) ^ v.UncompressedFileSize
}
// GetFileList returns the list of files in this MPQ
func (v *MPQ) GetFileList() ([]string, error) {
data, err := v.ReadFile("(listfile)")
if err != nil {
return nil, err
}
raw := strings.TrimRight(string(data), "\x00")
s := bufio.NewScanner(strings.NewReader(raw))
var filePaths []string
for s.Scan() {
filePath := s.Text()
filePaths = append(filePaths, filePath)
}
return filePaths, nil
}
// Path returns the MPQ file path
func (v *MPQ) Path() string {
return v.filePath
}
// Contains returns bool for whether the given filename exists in the mpq
func (v *MPQ) Contains(filename string) bool {
return v.hashEntryMap.Contains(filename)
}
// Size returns the size of the mpq in bytes
func (v *MPQ) Size() uint32 {
return v.data.ArchiveSize
}