refactor: use kgm crypto from parakeet-rs
chore: update deps
This commit is contained in:
Unlock Music Dev
@ -2,27 +2,24 @@ package kgm
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import (
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"bytes"
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"encoding/binary"
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"errors"
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"fmt"
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"io"
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"github.com/unlock-music/cli/algo/common"
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)
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var (
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vprHeader = []byte{
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0x05, 0x28, 0xBC, 0x96, 0xE9, 0xE4, 0x5A, 0x43,
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0x91, 0xAA, 0xBD, 0xD0, 0x7A, 0xF5, 0x36, 0x31}
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kgmHeader = []byte{
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0x7C, 0xD5, 0x32, 0xEB, 0x86, 0x02, 0x7F, 0x4B,
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0xA8, 0xAF, 0xA6, 0x8E, 0x0F, 0xFF, 0x99, 0x14}
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ErrKgmMagicHeader = errors.New("kgm/vpr magic header not matched")
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)
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type Decoder struct {
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file []byte
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key []byte
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maskFunc func(int) byte
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audio []byte
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header Header
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initializer kgmCryptoInitializer
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file []byte
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audio []byte
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}
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type kgmCryptoInitializer func(header *Header, body io.Reader) (io.Reader, error)
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var kgmCryptoInitializers = map[uint32]kgmCryptoInitializer{
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3: newKgmCryptoV3,
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}
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func NewDecoder(file []byte) common.Decoder {
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@ -44,31 +41,34 @@ func (d *Decoder) GetMeta() common.Meta {
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}
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func (d *Decoder) Validate() error {
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if bytes.Equal(kgmHeader, d.file[:len(kgmHeader)]) {
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d.maskFunc = getKgmMask
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} else if bytes.Equal(vprHeader, d.file[:len(vprHeader)]) {
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d.maskFunc = getVprMask
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} else {
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return ErrKgmMagicHeader
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if err := d.header.FromBytes(d.file); err != nil {
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return err
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}
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// TODO; validate crypto version
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var ok bool
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d.initializer, ok = kgmCryptoInitializers[d.header.CryptoVersion]
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if !ok {
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return fmt.Errorf("kgm: unsupported crypto version %d", d.header.CryptoVersion)
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}
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d.key = d.file[0x1c:0x2c]
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d.key = append(d.key, 0x00)
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_ = d.file[0x2c:0x3c] //todo: key2
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return nil
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}
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func (d *Decoder) Decode() error {
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headerLen := binary.LittleEndian.Uint32(d.file[0x10:0x14])
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d.audio = d.file[headerLen:]
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d.audio = d.file[d.header.AudioOffset:]
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for i := 0; i < len(d.audio); i++ {
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med8 := d.audio[i] ^ d.key[i%17] ^ d.maskFunc(i)
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d.audio[i] = med8 ^ (med8&0xf)<<4
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r, err := d.initializer(&d.header, bytes.NewReader(d.audio))
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if err != nil {
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return fmt.Errorf("kgm: failed to initialize crypto: %w", err)
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}
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d.audio, err = io.ReadAll(r)
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if err != nil {
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return fmt.Errorf("kgm: failed to decrypt audio: %w", err)
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}
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return nil
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}
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func init() {
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// Kugou
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common.RegisterDecoder("kgm", false, NewDecoder)
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64
algo/kgm/kgm_header.go
Normal file
64
algo/kgm/kgm_header.go
Normal file
@ -0,0 +1,64 @@
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package kgm
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import (
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"bytes"
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"encoding/binary"
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"errors"
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"fmt"
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"io"
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)
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var (
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vprHeader = []byte{
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0x05, 0x28, 0xBC, 0x96, 0xE9, 0xE4, 0x5A, 0x43,
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0x91, 0xAA, 0xBD, 0xD0, 0x7A, 0xF5, 0x36, 0x31,
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}
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kgmHeader = []byte{
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0x7C, 0xD5, 0x32, 0xEB, 0x86, 0x02, 0x7F, 0x4B,
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0xA8, 0xAF, 0xA6, 0x8E, 0x0F, 0xFF, 0x99, 0x14,
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}
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ErrKgmMagicHeader = errors.New("kgm magic header not matched")
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)
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// Header is the header of a KGM file.
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type Header struct {
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MagicHeader []byte // 0x00-0x0f: magic header
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AudioOffset uint32 // 0x10-0x13: offset of audio data
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CryptoVersion uint32 // 0x14-0x17: crypto version
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CryptoSlot uint32 // 0x18-0x1b: crypto key slot
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CryptoTestData []byte // 0x1c-0x2b: crypto test data
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CryptoKey []byte // 0x2c-0x3b: crypto key
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}
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func (h *Header) FromFile(rd io.ReadSeeker) error {
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if _, err := rd.Seek(0, io.SeekStart); err != nil {
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return fmt.Errorf("kgm seek start: %w", err)
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}
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buf := make([]byte, 0x3c)
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if _, err := io.ReadFull(rd, buf); err != nil {
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return fmt.Errorf("kgm read header: %w", err)
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}
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return h.FromBytes(buf)
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}
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func (h *Header) FromBytes(buf []byte) error {
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if len(buf) < 0x3c {
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return errors.New("invalid kgm header length")
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}
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h.MagicHeader = buf[:0x10]
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if !bytes.Equal(kgmHeader, h.MagicHeader) && !bytes.Equal(vprHeader, h.MagicHeader) {
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return ErrKgmMagicHeader
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}
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h.AudioOffset = binary.LittleEndian.Uint32(buf[0x10:0x14])
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h.CryptoVersion = binary.LittleEndian.Uint32(buf[0x14:0x18])
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h.CryptoSlot = binary.LittleEndian.Uint32(buf[0x18:0x1c])
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h.CryptoTestData = buf[0x1c:0x2c]
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h.CryptoKey = buf[0x2c:0x3c]
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return nil
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}
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66
algo/kgm/kgm_v3.go
Normal file
66
algo/kgm/kgm_v3.go
Normal file
@ -0,0 +1,66 @@
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package kgm
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import (
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"crypto/md5"
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"fmt"
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"io"
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)
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// kgmCryptoV3 is kgm file crypto v3
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type kgmCryptoV3 struct {
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slotBox []byte
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fileBox []byte
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rd io.Reader
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offset int
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}
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var kgmV3Slot2Key = map[uint32][]byte{
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1: {0x6C, 0x2C, 0x2F, 0x27},
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}
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func newKgmCryptoV3(header *Header, body io.Reader) (io.Reader, error) {
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c := &kgmCryptoV3{rd: body}
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slotKey, ok := kgmV3Slot2Key[header.CryptoSlot]
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if !ok {
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return nil, fmt.Errorf("kgm3: unknown crypto slot %d", header.CryptoSlot)
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}
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c.slotBox = kugouMD5(slotKey)
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c.fileBox = append(kugouMD5(header.CryptoKey), 0x6b)
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return c, nil
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}
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func (d *kgmCryptoV3) Read(buf []byte) (int, error) {
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n, err := d.rd.Read(buf)
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if n > 0 {
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d.decrypt(buf[:n], d.offset)
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d.offset += n
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}
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return n, err
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}
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func (d *kgmCryptoV3) decrypt(b []byte, offset int) {
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for i := 0; i < len(b); i++ {
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b[i] ^= d.fileBox[(offset+i)%len(d.fileBox)]
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b[i] ^= b[i] << 4
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b[i] ^= d.slotBox[(offset+i)%len(d.slotBox)]
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b[i] ^= xorCollapseUint32(uint32(offset + i))
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}
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}
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func xorCollapseUint32(i uint32) byte {
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return byte(i) ^ byte(i>>8) ^ byte(i>>16) ^ byte(i>>24)
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}
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func kugouMD5(b []byte) []byte {
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digest := md5.Sum(b)
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ret := make([]byte, 16)
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for i := 0; i < md5.Size; i += 2 {
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ret[i] = digest[14-i]
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ret[i+1] = digest[14-i+1]
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}
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return ret
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}
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@ -1,88 +0,0 @@
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package kgm
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import (
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_ "embed"
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)
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var kgmMaskTable1 = [...]byte{
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0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
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0x00, 0x01, 0x21, 0x01, 0x61, 0x01, 0x21, 0x01, 0xe1, 0x01, 0x21, 0x01, 0x61, 0x01, 0x21, 0x01,
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0xd2, 0x23, 0x02, 0x02, 0x42, 0x42, 0x02, 0x02, 0xc2, 0xc2, 0x02, 0x02, 0x42, 0x42, 0x02, 0x02,
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0xd3, 0xd3, 0x02, 0x03, 0x63, 0x43, 0x63, 0x03, 0xe3, 0xc3, 0xe3, 0x03, 0x63, 0x43, 0x63, 0x03,
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0x94, 0xb4, 0x94, 0x65, 0x04, 0x04, 0x04, 0x04, 0x84, 0x84, 0x84, 0x84, 0x04, 0x04, 0x04, 0x04,
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0x95, 0x95, 0x95, 0x95, 0x04, 0x05, 0x25, 0x05, 0xe5, 0x85, 0xa5, 0x85, 0xe5, 0x05, 0x25, 0x05,
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0xd6, 0xb6, 0x96, 0xb6, 0xd6, 0x27, 0x06, 0x06, 0xc6, 0xc6, 0x86, 0x86, 0xc6, 0xc6, 0x06, 0x06,
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0xd7, 0xd7, 0x97, 0x97, 0xd7, 0xd7, 0x06, 0x07, 0xe7, 0xc7, 0xe7, 0x87, 0xe7, 0xc7, 0xe7, 0x07,
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0x18, 0x38, 0x18, 0x78, 0x18, 0x38, 0x18, 0xe9, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08,
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0x19, 0x19, 0x19, 0x19, 0x19, 0x19, 0x19, 0x19, 0x08, 0x09, 0x29, 0x09, 0x69, 0x09, 0x29, 0x09,
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0xda, 0x3a, 0x1a, 0x3a, 0x5a, 0x3a, 0x1a, 0x3a, 0xda, 0x2b, 0x0a, 0x0a, 0x4a, 0x4a, 0x0a, 0x0a,
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0xdb, 0xdb, 0x1b, 0x1b, 0x5b, 0x5b, 0x1b, 0x1b, 0xdb, 0xdb, 0x0a, 0x0b, 0x6b, 0x4b, 0x6b, 0x0b,
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0x9c, 0xbc, 0x9c, 0x7c, 0x1c, 0x3c, 0x1c, 0x7c, 0x9c, 0xbc, 0x9c, 0x6d, 0x0c, 0x0c, 0x0c, 0x0c,
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0x9d, 0x9d, 0x9d, 0x9d, 0x1d, 0x1d, 0x1d, 0x1d, 0x9d, 0x9d, 0x9d, 0x9d, 0x0c, 0x0d, 0x2d, 0x0d,
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0xde, 0xbe, 0x9e, 0xbe, 0xde, 0x3e, 0x1e, 0x3e, 0xde, 0xbe, 0x9e, 0xbe, 0xde, 0x2f, 0x0e, 0x0e,
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0xdf, 0xdf, 0x9f, 0x9f, 0xdf, 0xdf, 0x1f, 0x1f, 0xdf, 0xdf, 0x9f, 0x9f, 0xdf, 0xdf, 0x0e, 0x0f,
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0x00, 0x20, 0x00, 0x60, 0x00, 0x20, 0x00, 0xe0, 0x00, 0x20, 0x00, 0x60, 0x00, 0x20, 0x00, 0xf1,
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}
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var kgmMaskTable2 = [...]byte{
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0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
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0x00, 0x01, 0x23, 0x01, 0x67, 0x01, 0x23, 0x01, 0xef, 0x01, 0x23, 0x01, 0x67, 0x01, 0x23, 0x01,
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0xdf, 0x21, 0x02, 0x02, 0x46, 0x46, 0x02, 0x02, 0xce, 0xce, 0x02, 0x02, 0x46, 0x46, 0x02, 0x02,
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0xde, 0xde, 0x02, 0x03, 0x65, 0x47, 0x65, 0x03, 0xed, 0xcf, 0xed, 0x03, 0x65, 0x47, 0x65, 0x03,
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0x9d, 0xbf, 0x9d, 0x63, 0x04, 0x04, 0x04, 0x04, 0x8c, 0x8c, 0x8c, 0x8c, 0x04, 0x04, 0x04, 0x04,
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0x9c, 0x9c, 0x9c, 0x9c, 0x04, 0x05, 0x27, 0x05, 0xeb, 0x8d, 0xaf, 0x8d, 0xeb, 0x05, 0x27, 0x05,
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0xdb, 0xbd, 0x9f, 0xbd, 0xdb, 0x25, 0x06, 0x06, 0xca, 0xca, 0x8e, 0x8e, 0xca, 0xca, 0x06, 0x06,
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0xda, 0xda, 0x9e, 0x9e, 0xda, 0xda, 0x06, 0x07, 0xe9, 0xcb, 0xe9, 0x8f, 0xe9, 0xcb, 0xe9, 0x07,
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0x19, 0x3b, 0x19, 0x7f, 0x19, 0x3b, 0x19, 0xe7, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08,
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0x18, 0x18, 0x18, 0x18, 0x18, 0x18, 0x18, 0x18, 0x08, 0x09, 0x2b, 0x09, 0x6f, 0x09, 0x2b, 0x09,
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0xd7, 0x39, 0x1b, 0x39, 0x5f, 0x39, 0x1b, 0x39, 0xd7, 0x29, 0x0a, 0x0a, 0x4e, 0x4e, 0x0a, 0x0a,
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0xd6, 0xd6, 0x1a, 0x1a, 0x5e, 0x5e, 0x1a, 0x1a, 0xd6, 0xd6, 0x0a, 0x0b, 0x6d, 0x4f, 0x6d, 0x0b,
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0x95, 0xb7, 0x95, 0x7b, 0x1d, 0x3f, 0x1d, 0x7b, 0x95, 0xb7, 0x95, 0x6b, 0x0c, 0x0c, 0x0c, 0x0c,
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0x94, 0x94, 0x94, 0x94, 0x1c, 0x1c, 0x1c, 0x1c, 0x94, 0x94, 0x94, 0x94, 0x0c, 0x0d, 0x2f, 0x0d,
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0xd3, 0xb5, 0x97, 0xb5, 0xd3, 0x3d, 0x1f, 0x3d, 0xd3, 0xb5, 0x97, 0xb5, 0xd3, 0x2d, 0x0e, 0x0e,
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0xd2, 0xd2, 0x96, 0x96, 0xd2, 0xd2, 0x1e, 0x1e, 0xd2, 0xd2, 0x96, 0x96, 0xd2, 0xd2, 0x0e, 0x0f,
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0x00, 0x22, 0x00, 0x66, 0x00, 0x22, 0x00, 0xee, 0x00, 0x22, 0x00, 0x66, 0x00, 0x22, 0x00, 0xfe,
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}
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var kgmMaskTable3 = [...]byte{
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0xB8, 0xD5, 0x3D, 0xB2, 0xE9, 0xAF, 0x78, 0x8C, 0x83, 0x33, 0x71, 0x51, 0x76, 0xA0, 0xCD, 0x37,
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0x2F, 0x3E, 0x35, 0x8D, 0xA9, 0xBE, 0x98, 0xB7, 0xE7, 0x8C, 0x22, 0xCE, 0x5A, 0x61, 0xDF, 0x68,
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0x69, 0x89, 0xFE, 0xA5, 0xB6, 0xDE, 0xA9, 0x77, 0xFC, 0xC8, 0xBD, 0xBD, 0xE5, 0x6D, 0x3E, 0x5A,
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0x36, 0xEF, 0x69, 0x4E, 0xBE, 0xE1, 0xE9, 0x66, 0x1C, 0xF3, 0xD9, 0x02, 0xB6, 0xF2, 0x12, 0x9B,
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0x44, 0xD0, 0x6F, 0xB9, 0x35, 0x89, 0xB6, 0x46, 0x6D, 0x73, 0x82, 0x06, 0x69, 0xC1, 0xED, 0xD7,
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0x85, 0xC2, 0x30, 0xDF, 0xA2, 0x62, 0xBE, 0x79, 0x2D, 0x62, 0x62, 0x3D, 0x0D, 0x7E, 0xBE, 0x48,
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0x89, 0x23, 0x02, 0xA0, 0xE4, 0xD5, 0x75, 0x51, 0x32, 0x02, 0x53, 0xFD, 0x16, 0x3A, 0x21, 0x3B,
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0x16, 0x0F, 0xC3, 0xB2, 0xBB, 0xB3, 0xE2, 0xBA, 0x3A, 0x3D, 0x13, 0xEC, 0xF6, 0x01, 0x45, 0x84,
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0xA5, 0x70, 0x0F, 0x93, 0x49, 0x0C, 0x64, 0xCD, 0x31, 0xD5, 0xCC, 0x4C, 0x07, 0x01, 0x9E, 0x00,
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0x1A, 0x23, 0x90, 0xBF, 0x88, 0x1E, 0x3B, 0xAB, 0xA6, 0x3E, 0xC4, 0x73, 0x47, 0x10, 0x7E, 0x3B,
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0x5E, 0xBC, 0xE3, 0x00, 0x84, 0xFF, 0x09, 0xD4, 0xE0, 0x89, 0x0F, 0x5B, 0x58, 0x70, 0x4F, 0xFB,
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0x65, 0xD8, 0x5C, 0x53, 0x1B, 0xD3, 0xC8, 0xC6, 0xBF, 0xEF, 0x98, 0xB0, 0x50, 0x4F, 0x0F, 0xEA,
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0xE5, 0x83, 0x58, 0x8C, 0x28, 0x2C, 0x84, 0x67, 0xCD, 0xD0, 0x9E, 0x47, 0xDB, 0x27, 0x50, 0xCA,
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0xF4, 0x63, 0x63, 0xE8, 0x97, 0x7F, 0x1B, 0x4B, 0x0C, 0xC2, 0xC1, 0x21, 0x4C, 0xCC, 0x58, 0xF5,
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0x94, 0x52, 0xA3, 0xF3, 0xD3, 0xE0, 0x68, 0xF4, 0x00, 0x23, 0xF3, 0x5E, 0x0A, 0x7B, 0x93, 0xDD,
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0xAB, 0x12, 0xB2, 0x13, 0xE8, 0x84, 0xD7, 0xA7, 0x9F, 0x0F, 0x32, 0x4C, 0x55, 0x1D, 0x04, 0x36,
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0x52, 0xDC, 0x03, 0xF3, 0xF9, 0x4E, 0x42, 0xE9, 0x3D, 0x61, 0xEF, 0x7C, 0xB6, 0xB3, 0x93, 0x50,
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}
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func getKgmMask(i int) byte {
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offset := i >> 4
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value := byte(0)
|
||||
for offset >= 17 {
|
||||
value ^= kgmMaskTable1[offset%(16*17)]
|
||||
offset = offset >> 4
|
||||
value ^= kgmMaskTable2[offset%(16*17)]
|
||||
offset = offset >> 4
|
||||
}
|
||||
|
||||
return kgmMaskTable3[i%(16*17)] ^ value
|
||||
}
|
||||
|
||||
var vprMaskDiffKgm = []byte{
|
||||
0x75, 0x2F, 0x68, 0xC6, 0x25, 0xFE, 0x25, 0xEE,
|
||||
0xDF, 0x80, 0xC3, 0xFD, 0x38, 0xD6, 0xD3, 0x01,
|
||||
0x00,
|
||||
}
|
||||
|
||||
func getVprMask(i int) byte {
|
||||
return vprMaskDiffKgm[i%17] ^ getKgmMask(i)
|
||||
}
|
||||
Reference in New Issue
Block a user