Fix keygen

keygen.go

@@ -0,0 +1,82 @@
+package wiiudownloader
+
+import (
+	"crypto/aes"
+	"crypto/cipher"
+	"crypto/md5"
+	"crypto/sha1"
+	"encoding/hex"
+
+	"golang.org/x/crypto/pbkdf2"
+)
+
+const (
+	KEYGEN_SECRET = "fd040105060b111c2d49"
+)
+
+var (
+	keygen_pw = []byte{0x6d, 0x79, 0x70, 0x61, 0x73, 0x73}
+)
+
+func encryptAES(data []byte, key []byte, iv []byte) ([]byte, error) {
+	block, err := aes.NewCipher(key)
+	if err != nil {
+		return nil, err
+	}
+
+	paddedData := PKCS7Padding(data, aes.BlockSize)
+	encrypted := make([]byte, len(paddedData))
+
+	mode := cipher.NewCBCEncrypter(block, iv)
+	mode.CryptBlocks(encrypted, paddedData)
+
+	return encrypted, nil
+}
+
+func generateKey(tid string) (string, error) {
+	tmp := []byte(tid)
+	for tmp[0] == '0' && tmp[1] == '0' {
+		tmp = tmp[2:]
+	}
+
+	h := []byte(KEYGEN_SECRET + string(tmp))
+
+	bhl := len(h) >> 1
+	bh := make([]byte, bhl)
+	for i, j := 0, 0; j < bhl; i += 2 {
+		bh[j] = byte((h[i]%32+9)%25*16 + (h[i+1]%32+9)%25)
+		j++
+	}
+
+	md5sum := md5.Sum(bh)
+
+	key := pbkdf2WithSHA1(keygen_pw, md5sum[:], 20, 16)
+
+	iv := make([]byte, 16)
+	for i, j := 0, 0; j < 8; i += 2 {
+		iv[j] = byte((tid[i]%32+9)%25*16 + (tid[i+1]%32+9)%25)
+		j++
+	}
+	copy(iv[8:], make([]byte, 8))
+
+	encrypted, err := encryptAES(key, commonKey, iv)
+	if err != nil {
+		return "", err
+	}
+
+	return hex.EncodeToString(encrypted), nil
+}
+
+func pbkdf2WithSHA1(password, salt []byte, iterations, keyLength int) []byte {
+	return pbkdf2.Key(password, salt, iterations, keyLength, sha1.New)
+}
+
+func PKCS7Padding(data []byte, blockSize int) []byte {
+	padding := blockSize - (len(data) % blockSize)
+	paddedData := make([]byte, len(data)+padding)
+	copy(paddedData, data)
+	for i := len(data); i < len(paddedData); i++ {
+		paddedData[i] = byte(padding)
+	}
+	return paddedData
+}