validate password devise 1.0.x to 2.x

Export Devise 1.0.x Database to new Devise 2.1.x

#First you need to copy password_salt and encrypted_password to your new object model

#Using this because I have to export my database User to another application and old, 
# app are using devise 1.0.x and new app using 2.1.x


Class User < ActiveRecord::Base
 alias :devise_valid_password? :valid_password?
    def valid_password?(password)
      begin
        devise_valid_password?(password)
      rescue BCrypt::Errors::InvalidHash
        salt = password_salt
        digest = nil
        10.times { digest = ::Digest::SHA1.hexdigest('--' << [salt, digest, password, nil].flatten.join('--') << '--') }
        digest
        return false unless digest == encrypted_password
        logger.info "User #{email} is using the old password hashing method, updating attribute."
        self.password = password
        self.password_salt = nil # With this you will knew what object already using the new authentication by devise
        self.save
        true
      end
    end
end