github.com/Mrs4s/MiraiGo@v0.0.0-20240226124653-54bdd873e3fe/client/internal/auth/pow.go (about)

     1  package auth
     2  
     3  import (
     4  	"bytes"
     5  	"crypto/sha256"
     6  	"math/big"
     7  	"time"
     8  
     9  	"github.com/Mrs4s/MiraiGo/binary"
    10  )
    11  
    12  func CalcPow(data []byte) []byte {
    13  	r := binary.NewReader(data)
    14  	a := r.ReadByte()
    15  	typ := r.ReadByte()
    16  	c := r.ReadByte()
    17  	ok := r.ReadByte() != 0
    18  	e := r.ReadUInt16()
    19  	f := r.ReadUInt16()
    20  	src := r.ReadBytesShort()
    21  	tgt := r.ReadBytesShort()
    22  	cpy := r.ReadBytesShort()
    23  
    24  	var dst []byte
    25  	var elp, cnt uint32
    26  	if typ == 2 && len(tgt) == 32 {
    27  		start := time.Now()
    28  		tmp := new(big.Int).SetBytes(src)
    29  		hash := sha256.Sum256(tmp.Bytes())
    30  		one := big.NewInt(1)
    31  		for !bytes.Equal(hash[:], tgt) {
    32  			tmp = tmp.Add(tmp, one)
    33  			hash = sha256.Sum256(tmp.Bytes())
    34  			cnt++
    35  		}
    36  		ok = true
    37  		dst = tmp.Bytes()
    38  		elp = uint32(time.Since(start).Milliseconds())
    39  	}
    40  
    41  	w := binary.SelectWriter()
    42  	w.WriteByte(a)
    43  	w.WriteByte(typ)
    44  	w.WriteByte(c)
    45  	w.WriteBool(ok)
    46  	w.WriteUInt16(e)
    47  	w.WriteUInt16(f)
    48  	w.WriteBytesShort(src)
    49  	w.WriteBytesShort(tgt)
    50  	w.WriteBytesShort(cpy)
    51  	if ok {
    52  		w.WriteBytesShort(dst)
    53  		w.WriteUInt32(elp)
    54  		w.WriteUInt32(cnt)
    55  	}
    56  	return w.Bytes()
    57  }