github.com/LagrangeDev/LagrangeGo@v0.0.0-20240512064304-ad4a85e10cb4/client/packets/wtlogin/exchange.go (about)

     1  package wtlogin
     2  
     3  import (
     4  	"encoding/hex"
     5  
     6  	"github.com/LagrangeDev/LagrangeGo/client/packets/pb/login"
     7  	"github.com/LagrangeDev/LagrangeGo/internal/proto"
     8  	"github.com/LagrangeDev/LagrangeGo/utils"
     9  	"github.com/LagrangeDev/LagrangeGo/utils/binary"
    10  	"github.com/LagrangeDev/LagrangeGo/utils/crypto"
    11  	"github.com/LagrangeDev/LagrangeGo/utils/crypto/ecdh"
    12  )
    13  
    14  var encKey, _ = hex.DecodeString("e2733bf403149913cbf80c7a95168bd4ca6935ee53cd39764beebe2e007e3aee")
    15  
    16  func BuildKexExchangeRequest(uin uint32, guid string) ([]byte, error) {
    17  	encl, err := crypto.AESGCMEncrypt(proto.DynamicMessage{
    18  		1: uin,
    19  		2: guid,
    20  	}.Encode(), ecdh.P256().SharedKey())
    21  	if err != nil {
    22  		return nil, err
    23  	}
    24  
    25  	p2Hash := crypto.SHA256Digest(
    26  		binary.NewBuilder(nil).
    27  			WriteBytes(ecdh.P256().PublicKey()).
    28  			WriteU32(1).
    29  			WriteBytes(encl).
    30  			WriteU32(0).
    31  			WriteU32(uint32(utils.TimeStamp())).
    32  			ToBytes(),
    33  	)
    34  	encP2Hash, err := crypto.AESGCMEncrypt(p2Hash, encKey)
    35  	if err != nil {
    36  		return nil, err
    37  	}
    38  
    39  	return proto.DynamicMessage{
    40  		1: ecdh.P256().PublicKey(),
    41  		2: 1,
    42  		3: encl,
    43  		4: utils.TimeStamp(),
    44  		5: encP2Hash,
    45  	}.Encode(), nil
    46  }
    47  
    48  func ParseKeyExchangeResponse(response []byte) (key, sign []byte, err error) {
    49  	var p login.SsoKeyExchangeResponse
    50  	err = proto.Unmarshal(response, &p)
    51  	if err != nil {
    52  		return
    53  	}
    54  
    55  	shareKey, err := ecdh.P256().Exange(p.PublicKey)
    56  	if err != nil {
    57  		return
    58  	}
    59  
    60  	var decPb login.SsoKeyExchangeDecrypted
    61  	data, err := crypto.AESGCMDecrypt(p.GcmEncrypted, shareKey)
    62  	if err != nil {
    63  		return
    64  	}
    65  	err = proto.Unmarshal(data, &decPb)
    66  	if err != nil {
    67  		return
    68  	}
    69  
    70  	return decPb.GcmKey, decPb.Sign, nil
    71  }