OS versionAndroid OS 2.3.5_r1
Screen Lock Settings'Screen unlock security' lock screen can be set from Settings.apk.
Password and pattern information that used unlock screen is managed by 'LockPatternUtils'.
LockPatternUtils class overviewGenerate an SHA-1(and MD5) hash for the password / pattern.
Write the hash to file.
Check to see if a password matches the saved password / pattern.
Save password quality to DevicePolicyManager.