title: Grails Spring Security Plugin Migrate User Passwords from 1.2.7.3 to 2.0
body: <p>I am using Grails 2.3.2 and am trying to upgrade my Spring Security Core Plugin from 1.2.7.3 to 2.0.</p>
  
  <p>I made all the import changes and got my app to start, but I was unable to login.  One of the changes in 2.0 is that it uses the bcrypt algorithm for passwords, making all my old passwords useless.  So, I went through the password reset process in my app and sure enough after that I could log in just fine.</p>
  
  <p>But, I want to keep my old passwords for all my users, so I went and found the documentation for the 1.2.7.3 version of the plugin and looked up what algorithm it used: <a href="http://grails-plugins.github.io/grails-spring-security-core/docs/manual.1273/guide/12%20Password%20and%20Account%20Protection.html" rel="nofollow">http://grails-plugins.github.io/grails-spring-security-core/docs/manual.1273/guide/12%20Password%20and%20Account%20Protection.html</a></p>
  
  <p>According to these docs its default is SHA-256.  So, I added that config change, yet I still cannot log in.</p>
  
  <p>So, how can I migrate all my user's passwords to the 2.0 version of the plugin?  As of right now it doesn't seem possible...</p>