mirror of
https://github.com/Mezeporta/Erupe.git
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118 lines
2.5 KiB
Go
118 lines
2.5 KiB
Go
package decryption
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/*
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This code is HEAVILY based from
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https://github.com/Chakratos/ReFrontier/blob/master/ReFrontier/Unpack.cs
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*/
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import (
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"erupe-ce/common/byteframe"
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"io"
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)
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var m_shiftIndex int = 0
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var m_flag byte = byte(0)
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func UnpackSimple(data []byte) []byte {
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m_shiftIndex = 0
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m_flag = byte(0)
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bf := byteframe.NewByteFrameFromBytes(data)
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bf.SetLE()
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header := bf.ReadUint32()
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println("Decrypting")
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if header == 0x1A524B4A {
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bf.Seek(0x2, io.SeekCurrent)
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jpkType := bf.ReadUint16()
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println("JPK Type: ", jpkType)
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switch jpkType {
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case 3:
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startOffset := bf.ReadInt32()
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outSize := bf.ReadInt32()
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outBuffer := make([]byte, outSize)
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bf.Seek(int64(startOffset), io.SeekStart)
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ProcessDecode(bf, outBuffer)
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return outBuffer
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}
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}
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println("Skipping")
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return data
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}
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func ProcessDecode(data *byteframe.ByteFrame, outBuffer []byte) {
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outIndex := 0
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for int(data.Index()) < len(data.Data()) && outIndex < len(outBuffer)-1 {
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if JPKBitshift(data) == 0 {
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outBuffer[outIndex] = ReadByte(data)
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outIndex++
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continue
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} else {
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if JPKBitshift(data) == 0 {
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len := (JPKBitshift(data) << 1) | JPKBitshift(data)
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off := ReadByte(data)
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JPKCopy(outBuffer, int(off), int(len)+3, &outIndex)
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continue
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} else {
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hi := ReadByte(data)
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lo := ReadByte(data)
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var len int = int((hi & 0xE0)) >> 5
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var off int = ((int(hi) & 0x1F) << 8) | int(lo)
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if len != 0 {
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JPKCopy(outBuffer, off, len+2, &outIndex)
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continue
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} else {
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if JPKBitshift(data) == 0 {
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len := (JPKBitshift(data) << 3) | (JPKBitshift(data) << 2) | (JPKBitshift(data) << 1) | JPKBitshift(data)
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JPKCopy(outBuffer, off, int(len)+2+8, &outIndex)
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continue
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} else {
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temp := ReadByte(data)
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if temp == 0xFF {
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for i := 0; i < off+0x1B; i++ {
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outBuffer[outIndex] = ReadByte(data)
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outIndex++
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continue
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}
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} else {
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JPKCopy(outBuffer, off, int(temp)+0x1a, &outIndex)
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}
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}
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}
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}
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}
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}
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}
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func JPKBitshift(data *byteframe.ByteFrame) byte {
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m_shiftIndex--
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if m_shiftIndex < 0 {
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m_shiftIndex = 7
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m_flag = ReadByte(data)
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}
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return (byte)((m_flag >> m_shiftIndex) & 1)
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}
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func JPKCopy(outBuffer []byte, offset int, length int, index *int) {
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for i := 0; i < length; i++ {
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outBuffer[*index] = outBuffer[*index-offset-1]
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*index++
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}
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}
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func ReadByte(bf *byteframe.ByteFrame) byte {
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value := bf.ReadUint8()
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if value < 0 {
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println("Not implemented")
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}
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return byte(value)
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}
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