Password Complexity in Linux

[karthik keyan]

Hi All 
 
I would like to setup passwd complexity on our Linux servers .
 
Min 8 characters - 1 upper , 1 digit and 1 Lower character 
 
Last used 4 passwords should not be used 
 
And also i want to set Passwd expiry for user accounts which are already created and These passwd complexity should apply to users which has alreay been created .
 
I Need  your valuable help and advice 
 
Thanks & Regards
Karthik