android手机密码password.key文件加密方式？

Question

android手机被设置了密码，由于开了root并且开启了USB调试，在终端下

 adb pull /data/system/password.key ～/ 

，之后cat password.key

 B10DE316C14D82701D418D03B85A02EFBCD02DBFAEFEA0BA8E1007D6CB4AF9F281419D67

把这个文件删除之后，手机重启就不需要输入密码了，但是想知道这种加密方法，没有密码学基础，没有思路，看了网上的不少说是sha1。另：已经知道了手机上设置的密码为123654。求大神点拨。

Answer 1

参考 Android Forensics May 27
加密是类似下面的方法，盐值是在/data/data/com.android.providers.settings/databases/settings.db数据库secure的表里面，你文件里面看到的就是sha1+md5: (40位+32位)的值

public byte[] passwordToHash(String password)
{
    if (password == null)
    {
            return null;
        }
    String algo = null;
    byte[] hashed = null;
    try
        {
        byte[] saltedPassword = (password + getSalt()).getBytes();
        byte[] sha1 = MessageDigest.getInstance(algo = "SHA-1").digest(saltedPassword);
        byte[] md5 = MessageDigest.getInstance(algo = "MD5").digest(saltedPassword);
                hashed = (toHex(sha1) + toHex(md5)).getBytes();
        }
        catch (NoSuchAlgorithmException e)
    {
            Log.w(TAG, "Failed to encode string because of missing algorithm: " + algo);
    }
        return hashed;
}

1. Pull out the salt using adb. Salt is stored in the ‘secure’ table from /data/data/com.android.providers.settings/databases/settings.db
2. Get the password : sha1+md5: (40+32) (stored at /data/system/password.key)

Ex: 0C4C24508F0D29CF54FFC4DBC5520C3C10496F43313B4D3ADDFF8ACDD5C8DC3CA69CE740

1. Once you have the md5 and the salt you can brute force using the tools available in market (Ex hashcat) to get password.