diff --git a/mtkclient/Library/DA/xflash/xflash_lib.py b/mtkclient/Library/DA/xflash/xflash_lib.py
index d8a1ed9..b7a28b8 100755
--- a/mtkclient/Library/DA/xflash/xflash_lib.py
+++ b/mtkclient/Library/DA/xflash/xflash_lib.py
@@ -8,6 +8,8 @@ import sys
 from binascii import hexlify
 from struct import pack, unpack
 
+from Cryptodome.Util.number import long_to_bytes
+
 from mtkclient.Library.Auth.sla import generate_da_sla_signature
 from mtkclient.Library.DA.xflash.xflash_flash_param import NandExtension
 from mtkclient.Library.DA.xflash.xflash_param import Cmd, ChecksumAlgorithm, FtSystemOSE, DataType
@@ -1142,7 +1144,7 @@ class DAXFlash(metaclass=LogBase):
         rsakey = None
         from mtkclient.Library.Auth.sla_keys import da_sla_keys
         for key in da_sla_keys:
-            if da2.find(bytes.fromhex(key.n)) != -1:
+            if da2.find(long_to_bytes(key.n)) != -1:
                 rsakey = key
                 break
         if rsakey is None:
diff --git a/mtkclient/Library/DA/xml/xml_lib.py b/mtkclient/Library/DA/xml/xml_lib.py
index b4f34c1..ad399aa 100755
--- a/mtkclient/Library/DA/xml/xml_lib.py
+++ b/mtkclient/Library/DA/xml/xml_lib.py
@@ -7,6 +7,7 @@ from struct import pack, unpack
 from queue import Queue
 from threading import Thread
 
+from Cryptodome.Util.number import long_to_bytes
 from Cryptodome.Cipher import PKCS1_OAEP
 from Cryptodome.Hash import SHA256
 from Cryptodome.PublicKey import RSA
@@ -624,7 +625,7 @@ class DAXML(metaclass=LogBase):
                         from mtkclient.Library.Auth.sla_keys import da_sla_keys, SlaKey
                         for key in da_sla_keys:
                             if isinstance(key, SlaKey):
-                                if da2.find(bytes.fromhex(key.n)) != -1:
+                                if da2.find(long_to_bytes(key.n)) != -1:
                                     rsakey = key
                         if rsakey is None:
                             print("No valid sla key found, using dummy auth ....")