Shiro - how to login with hashed password -

i using shiro secure application, , problem how login hashed password following scenarios:

1, automatically login user after click on activation email.

2, login via facebook, find user facebookid database, , try login in, have hashed passwrod, have ways decrypt hashed password.

this how encrypt password stored in database:

new sha256hash(password).tohex() 

below login code.

subject currentuser = securityutils.getsubject(); if (!currentuser.isauthenticated()) {     usernamepasswordtoken token = new usernamepasswordtoken(email, password, rememberme);     currentuser.login(token); } 

bear me if question weird, , in advance.

the purpose of hash function undecryptable. no, can not decrypted. achieve both goals can configure additional realms. 1 email activation, other oauth login.

for email activation can create temporary account, create random activation token , send email. user clicks activation link , application tries authenticate user token provided in http request:

string token = //get request subject.authenticate(new activationtoken(token)); 

activation realm checks whether token valid. , if valid removes token account , authenticates it.

as facebook realm can use secret obtained outh authentication step user info , if there no erros authenticate user.