I am writ­ing a sort of we­b-based ad­min tool for a clien­t, and I had this prob­lem: How do you val­i­date a sys­tem us­er from a scrip­t?

Well, this is how:

def validPass(name,password):
     p=os.popen('/usr/bin/checkpassword-pam -s login -- /bin/true 3<&0','w')
     s='%s\000%s\000xxx\000'%(name,password)
     p.write(s)
     r=p.close()
     if r==None: #Success
             return True
     else:
             return False

Just get check­pass­word-­pam from some­where.

Or, if you use some oth­er sort of au­then­ti­ca­tion scheme, some oth­er check­pass­word. They are meant for qmail, but they are very handy :-)