Can you provide information on the encryption algorithm and key used for encrypting WiFi passphrase storage in Windows 10? I am attempting to gain understanding on this topic.
Upon examination of the XML file located at C:\ProgramData\Microsoft\Wlansvc\Profiles\Interfaces{INTERFACE UUID}, it appears that the stored passphrase is protected by an encryption method. However, I am unable to determine the specific algorithm and key used as it is not the user’s password, and all users have access to it.
3 Answers
Introduction
In today’s digitally connected world, Wi-Fi has become an essential part of our lives. It has made our lives easier by providing us with wireless internet connectivity. Windows 10, the most widely used operating system worldwide, stores Wi-Fi network information such as the SSID and passphrase in an encrypted format. This encrypted information is stored in XML files, which can be accessed using administrative privileges. In this blog post, we will explore the encryption algorithm used to encrypt Wi-Fi passphrase storage in Windows 10.
Wi-Fi Passphrase Storage in Windows 10
Windows 10 stores Wi-Fi network information in XML files located in the C:ProgramDataMicrosoftWlansvcProfilesInterfaces{INTERFACE UUID} directory. These XML files contain information about the Wi-Fi network, including the SSID, authentication method, and passphrase. The passphrase is the key used to connect to the Wi-Fi network.
Encryption of Wi-Fi Passphrase
The passphrase is stored in an encrypted format in the XML file. This is done to prevent unauthorized access to the Wi-Fi network. The encryption algorithm used to encrypt the passphrase is not publicly documented by Microsoft. However, it is known that the encryption is performed using a key that is unique to each user account.
Encryption Algorithm and Key
The encryption algorithm used to encrypt the Wi-Fi passphrase storage in Windows 10 is not publicly documented. However, it is believed that Microsoft uses the Advanced Encryption Standard (AES) algorithm to encrypt the passphrase. AES is a widely used encryption algorithm that is known for its security and efficiency.
The key used to encrypt the passphrase is unique to each user account. This means that each user account has its own key, which is used to encrypt the Wi-Fi passphrase. The key is derived from the user’s password using a key derivation function (KDF). The KDF used by Microsoft is not publicly documented.
Accessing the Encrypted Passphrase
To access the encrypted passphrase, you need administrative privileges on the Windows 10 computer. Once you have administrative privileges, you can navigate to the C:ProgramDataMicrosoftWlansvcProfilesInterfaces{INTERFACE UUID} directory and open the XML file containing the Wi-Fi network information. You can then use a decryption tool to decrypt the passphrase.
Security of Wi-Fi Passphrase Storage
The encryption of Wi-Fi passphrase storage in Windows 10 is an essential security measure. It prevents unauthorized access to the Wi-Fi network, which could result in the theft of sensitive information. However, the security of the Wi-Fi passphrase storage depends on the strength of the user’s password.
If the user’s password is weak, it can be easily cracked, and the Wi-Fi passphrase can be decrypted. Therefore, it is essential to use a strong password to protect the Wi-Fi passphrase. A strong password should be at least 12 characters long and should contain a combination of uppercase and lowercase letters, numbers, and special characters.
Conclusion
In conclusion, Windows 10 uses an encryption algorithm to encrypt Wi-Fi passphrase storage. The encryption algorithm used is not publicly documented, but it is believed to be the Advanced Encryption Standard (AES) algorithm. The key used to encrypt the passphrase is unique to each user account and is derived from the user’s password using a key derivation function (KDF). The security of the Wi-Fi passphrase storage depends on the strength of the user’s password. Therefore, it is essential to use a strong password to protect the Wi-Fi passphrase.
The encryption algorithm used to encrypt WiFi passphrase storage in Windows 10 is the Advanced Encryption Standard (AES) algorithm, specifically AES-128. The key used is derived from the user’s login credentials and the network’s SSID (service set identifier). The encryption key is unique to each user and each wireless network they have connected to, which means that the passphrase cannot be decrypted by another user even if they have access to the same XML file.
In Windows 10, the storage of WiFi location information has changed from previous versions such as Windows Vista, 7, and 8. Instead of using the registry, all information is now stored in the following file: C:\ProgramData\Microsoft\Wlansvc\Profiles\Interfaces{xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx}{Random-GUID}.xml
Each wireless device is represented by its unique GUID {xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx} and its settings are stored in an XML file with a random GUID name.
Encryption and decryption in Windows 10 is done using the ‘Windows Cryptography’ functions. The ‘Wireless Configuration Manager’ uses the CryptProtectData functions to encrypt wireless keys and passwords. The signature at the beginning of each encrypted password is 01000000D08C9DDF0115D1118C7A00C0.
Decryption is done using the CryptUnprotectData function, but it must be run as the system. This can be done by creating a scheduled task as the system using the task scheduler, using the System Internals program psexec64.exe, running CMD as an administrator and navigating to the folder of the exe, or by running powershell as an administrator and navigating to the exe.
Another method, although considered risky, is to inject the code via a remote thread in the system process LSASS.EXE. This requires knowledge of C++ and the procedure can be found on nirsoft.net.
The CryptProtectData and CryptUnprotectData functions are based on the Data Protection API (DPAPI). These user interfaces are available through the Windows SDK and MSDN Library. DPAPI requires a password to protect information and uses the Triple-DES algorithm and strong keys for encryption. The MasterKey, which is protected by the user’s password, is initially generated by DPAPI and then used with Triple-DES to encrypt data.
In summary, Windows 10 stores WiFi location information in the file C:\ProgramData\Microsoft\Wlansvc\Profiles\Interfaces{xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx}{Random-GUID}.xml, where each wireless device is represented by its unique GUID and settings are stored in an XML file with a random GUID name. The encryption and decryption of wireless keys and passwords is done using the CryptProtectData and CryptUnprotectData functions respectively, which are based on the Data Protection API (DPAPI). Decryption of the wireless keys and passwords can be done by running the CryptUnprotectData function as the system, but it can be risky if done through remote thread in the system process LSASS.EXE.