mirror of
https://github.com/muun/recovery.git
synced 2025-02-23 03:22:31 -05:00
76 lines
2.0 KiB
Go
76 lines
2.0 KiB
Go
package libwallet
|
|
|
|
import (
|
|
"bytes"
|
|
"crypto/aes"
|
|
"crypto/cipher"
|
|
"encoding/binary"
|
|
|
|
"github.com/btcsuite/btcd/btcec"
|
|
"github.com/btcsuite/btcutil/base58"
|
|
"github.com/pkg/errors"
|
|
)
|
|
|
|
type ChallengePublicKey struct {
|
|
pubKey *btcec.PublicKey
|
|
}
|
|
|
|
func NewChallengePublicKeyFromSerialized(serializedKey []byte) (*ChallengePublicKey, error) {
|
|
|
|
pubKey, err := btcec.ParsePubKey(serializedKey, btcec.S256())
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
return &ChallengePublicKey{pubKey}, nil
|
|
}
|
|
|
|
func (k *ChallengePublicKey) EncryptKey(privKey *HDPrivateKey, recoveryCodeSalt []byte, birthday int) (string, error) {
|
|
|
|
const (
|
|
chainCodeStart = 13
|
|
chainCodeLength = 32
|
|
privKeyStart = 46
|
|
privKeyLength = 32
|
|
)
|
|
|
|
rawHDKey := base58.Decode(privKey.String())
|
|
plaintext := make([]byte, 0)
|
|
plaintext = append(plaintext, rawHDKey[privKeyStart:privKeyStart+privKeyLength]...)
|
|
plaintext = append(plaintext, rawHDKey[chainCodeStart:chainCodeStart+chainCodeLength]...)
|
|
if len(plaintext) != 64 {
|
|
return "", errors.Errorf("failed to encrypt key: expected payload of 64 bytes, found %v", len(plaintext))
|
|
}
|
|
|
|
privEph, err := btcec.NewPrivateKey(btcec.S256())
|
|
if err != nil {
|
|
return "", errors.Wrapf(err, "failed to encrypt key")
|
|
}
|
|
|
|
sharedSecret, _ := k.pubKey.ScalarMult(k.pubKey.X, k.pubKey.Y, privEph.D.Bytes())
|
|
serializedPubkey := privEph.PubKey().SerializeCompressed()
|
|
iv := serializedPubkey[len(serializedPubkey)-aes.BlockSize:]
|
|
|
|
block, err := aes.NewCipher(sharedSecret.Bytes())
|
|
if err != nil {
|
|
return "", err
|
|
}
|
|
|
|
ciphertext := make([]byte, len(plaintext))
|
|
|
|
mode := cipher.NewCBCEncrypter(block, iv)
|
|
mode.CryptBlocks(ciphertext, plaintext)
|
|
|
|
birthdayBytes := make([]byte, 2)
|
|
binary.BigEndian.PutUint16(birthdayBytes, uint16(birthday))
|
|
|
|
result := make([]byte, 0, 1+2+33+len(ciphertext)+len(recoveryCodeSalt))
|
|
buf := bytes.NewBuffer(result)
|
|
buf.WriteByte(2)
|
|
buf.Write(birthdayBytes)
|
|
buf.Write(privEph.PubKey().SerializeCompressed())
|
|
buf.Write(ciphertext)
|
|
buf.Write(recoveryCodeSalt)
|
|
|
|
return base58.Encode(buf.Bytes()), nil
|
|
} |