169 lines
6.9 KiB
Markdown
169 lines
6.9 KiB
Markdown
# RuCaptcha
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[](https://badge.fury.io/rb/rucaptcha)
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[](https://travis-ci.org/huacnlee/rucaptcha)
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This is a Captcha gem for Rails Applications which generates captcha image by C code.
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[中文介绍和使用说明](https://ruby-china.org/topics/27832)
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## Example
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**default style**
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**outline enable**
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## Feature
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- No dependencies. No ImageMagick. No RMagick;
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- For Rails Application;
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- Simple, Easy to use;
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- High performance.
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## Usage
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Put rucaptcha in your `Gemfile`:
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```
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gem 'rucaptcha'
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```
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Create `config/initializers/rucaptcha.rb`
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```rb
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RuCaptcha.configure do
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# Color style, default: :colorful, allows: [:colorful, :black_white]
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# self.style = :colorful
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# Custom captcha code expire time if you need, default: 2 minutes
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# self.expires_in = 120
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# [Requirement / 重要]
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# Store Captcha code where, this config more like Rails config.cache_store
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# default: Read config info from `Rails.application.config.cache_store`
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# But RuCaptcha requirements cache_store not in [:null_store, :memory_store, :file_store]
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# 默认：会从 Rails 配置的 cache_store 里面读取相同的配置信息，并尝试用可以运行的方式，用于存储验证码字符
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# 但如果是 [:null_store, :memory_store, :file_store] 之类的，你可以通过下面的配置项单独给 RuCaptcha 配置 cache_store
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self.cache_store = :mem_cache_store
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# Chars length, default: 5, allows: [3 - 7]
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# self.length = 5
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# enable/disable Strikethrough.
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# self.strikethrough = true
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# enable/disable Outline style, for hard mode
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# self.outline = false
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end
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```
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RuCaptcha 没有使用 Rails Session 来存储验证码信息，因为 Rails 的默认 Session 是存储在 Cookie 里面，如果验证码存在里面会存在 [Replay attack](https://en.wikipedia.org/wiki/Replay_attack) 漏洞，导致验证码关卡被攻破。
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所以我在设计上要求 RuCaptcha 得配置一个可以支持分布式的后端存储方案例如：Memcached 或 Redis 以及其他可以支持分布式的 cache_store 方案。
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同时，为了保障易用性，默认会尝试使用 `:file_store` 的方式，将验证码存在应用程序的 `tmp/cache/rucaptcha/session` 目录（但请注意，多机器部署这样是无法正常运作的）。
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所以，我建议大家使用的时候，配置上 `cache_store` （详见 [Rails Guides 缓存配置部分](https://ruby-china.github.io/rails-guides/caching_with_rails.html#%E9%85%8D%E7%BD%AE)的文档）到一个 Memcached 或 Redis，这才是最佳实践。
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#
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(RuCaptha do not use Rails Session to store captcha information. As the default session is stored in Cookie in Rails, there's a [Replay attack](https://en.wikipedia.org/wiki/Replay_attack) bug which may causes capthcha being destroyed if we store captcha in Rails Session.
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So in my design I require RuCaptcha to configure a distributed backend storage scheme, such as Memcached, Redis or other cache_store schemes which support distribution.
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Meanwhile, for the ease of use, RuCapthca would try to use `:file_store` by default and store the capthca in `tmp/cache/rucaptcha/session` directory (kindly note that it's not working if deploy on multiple machine).
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For recommendation, configure the `cache_store`（more details on [Rails Guides Configuration of Cache Stores](http://guides.rubyonrails.org/caching_with_rails.html#configuration)） to Memcached or Redis, that would be the best practice.)
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#
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Controller `app/controller/account_controller.rb`
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When you called `verify_rucaptcha?`, it uses value from `params[:_rucaptcha]` to validate.
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```rb
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class AccountController < ApplicationController
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def create
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@user = User.new(params[:user])
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if verify_rucaptcha?(@user) && @user.save
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redirect_to root_path, notice: 'Sign up successed.'
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else
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render 'account/new'
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end
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end
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end
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class ForgotPasswordController < ApplicationController
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def create
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# without any args
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if verify_rucaptcha?
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to_send_email
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else
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redirect_to '/forgot-password', alert: 'Invalid captcha code.'
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end
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end
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end
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```
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> TIP: Sometimes you may need to keep last verified captcha code in session on `verify_rucaptcha?` method call, you can use `keep_session: true`. For example: `verify_rucaptcha? @user, keep_session: true`.
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View `app/views/account/new.html.erb`
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```erb
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<form method="POST">
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...
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<div class="form-group">
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<%= rucaptcha_input_tag(class: 'form-control', placeholder: 'Input Captcha') %>
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<%= rucaptcha_image_tag(alt: 'Captcha') %>
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</div>
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...
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<div class="form-group">
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<button type="submit" class="btn btn-primary">Submit</button>
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</div>
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</form>
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```
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And if you are using [Devise](https://github.com/plataformatec/devise), you can read this reference to add validation: [RuCaptcha with Devise](https://github.com/huacnlee/rucaptcha/wiki/Working-with-Devise).
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### Write your test skip captcha validation
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for RSpec
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```rb
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describe 'sign up and login', type: :feature do
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before do
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allow_any_instance_of(ActionController::Base).to receive(:verify_rucaptcha?).and_return(true)
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end
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it { ... }
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end
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```
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for MiniTest
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```rb
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class ActionDispatch::IntegrationTest
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def sign_in(user)
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ActionController::Base.any_instance.stubs(:verify_rucaptcha?).returns(true)
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post user_session_path \
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'user[email]' => user.email,
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'user[password]' => user.password
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end
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end
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```
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### Invalid message without Devise
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When you are using this gem without Devise, you may find out that the invalid message is missing.
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For this case, use the trick below to add your i18n invalid message manually.
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```rb
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if verify_rucaptcha?(@user) && @user.save
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do_whatever_you_want
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redirect_to someplace_you_want
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else
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# this is the trick
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@user.errors.add(:base, t('rucaptcha.invalid'))
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render :new
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end
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```
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