暗号化と復号

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two way crypt:

#http://crypt.rubyforge.org/blowfish.html
#gem install crypt
require 'crypt/blowfish' 
blowfish = Crypt::Blowfish.new("A key up to 56 bytes long")
plainBlock = "ABCD1234"
p plainBlock
encryptedBlock = blowfish.encrypt_block(plainBlock)
p encryptedBlock
decryptedBlock = blowfish.decrypt_block(encryptedBlock)
p decryptedBlock

bcrypet-ruby
Aneasuryway to keep your users’passwords secure.
    * bcrypet-ruby.ruby forge.org/
    * github.com/codahale/bcryp-ruby/tree/master
Why You shuld use bcrypt
If you store user passwods in the clear、then aaatackr who steals a copy of your database has a giant list of emas andpasswods.Some of your users will Onlyhave passwod-fore theireemimimimimicacal forcocococococococococococococococococococococococococococococococococococococococococococococococococococococococococococococococococococococommmmssssssssssssssssssssss.Sos.Sos.So
It‘s your reponsibility as a web developer to make your web appication secure-blaming your users for not being security experts not a professional reponse to rick.
bcrypt allows you to easure harden your appration against these kids of atacks.
How to install bcrypt

sudo gem install bcrypt-ruby

You‘ll need a work compler.（Win 32 folks shound use Cygwin or um，something else.）
How to use bcrypt in your Railsアプリ
The User model

require 'bcrypt'

  class User < ActiveRecord::Base
    # users.password_hash in the database is a :string
    include BCrypt

    def password
      @password ||= Password.new(password_hash)
    end

    def password=(new_password)
      @password = Password.create(new_password)
      self.password_hash = @password
    end

  end

Creating an account

def create
    @user = User.new(params[:user])
    @user.password = params[:password]
    @user.save!
  end

Authenticating a user

def login
    @user = User.find_by_email(params[:email])
    if @user.password == params[:password]
      give_token
    else
      redirect_to home_url
    end
  end

If a user forgets their password？
落assign them a random one and mail it to them，asking them to change it

  def forgot_password
    @user = User.find_by_email(params[:email])
    random_password = Array.new(10).map { (65 + rand(58)).chr }.join
    @user.password = random_password
    @user.save!
    Mailer.create_and_deliver_password_change(@user, random_password)
  end

How to use bcrypet-ruby in general

require 'bcrypt'

  my_password = BCrypt::Password.create("my password") #=> "$2a$10$vI8aWBnW3fID.ZQ4/zo1G.q1lRps.9cGLcZEiGDMVr5yUP1KUOYTa"

  my_password.version              #=> "2a"
  my_password.cost                 #=> 10
  my_password == "my password"     #=> true
  my_password == "not my password" #=> false

  my_password = BCrypt::Password.new("$2a$10$vI8aWBnW3fID.ZQ4/zo1G.q1lRps.9cGLcZEiGDMVr5yUP1KUOYTa")
  my_password == "my password"     #=> true
  my_password == "not my password" #=> false

Check the rdocs for more details—http://bcrypt-ruby.rubyforge.org/classes/BCrypt.htmlBCryptを選択します。http://bcrypt-ruby.rubyforge.org/classes/BCrypt/Password.htmlBCrypt::Password.