重复授权在使用Doorkeeper（资源所有者凭据流）时会产生422错误。

Question

我是Rails和Web开发的新手。尝试使用Rails+Devise+Doorkeeper实现移动应用的简单API（就像https://github.com/doorkeeper-gem/doorkeeper-provider-app中所示）。

遇到的问题是，如果用户已经收到令牌，他将无法进行授权请求（POST /oauth/token）。即：

curl -F grant_type=password -F username=[e-mail] -F password=12345678 -X POST http://api.to_the_trip.dev/oauth/token

首次接收：

{"access_token":"eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.eyJ1c2VyIjp7ImlkIjoyLCJlbWFpbCI6IjFAdG90aGV0cmlwLmNvbSJ9fQ.dYai6nH_KYb9YbDltqwFuzCO3i0igR_gw2T7u_TeVcI","token_type":"bearer","expires_in":7200,"created_at":1435864812}

Token会被存储到oauth_access_tokens表中（对于JWT来说不是必要的，但也不是问题）。

如果我重复这个请求，就会收到422错误和类似于rails页面的内容。

    ActiveRecord::RecordInvalid in Doorkeeper::TokensController#create
Validation failed: Token has already been taken

activerecord (4.2.3) lib/active_record/validations.rb:79:in `raise_record_invalid'
activerecord (4.2.3) lib/active_record/validations.rb:43:in `save!'
activerecord (4.2.3) lib/active_record/attribute_methods/dirty.rb:29:in `save!'
activerecord (4.2.3) lib/active_record/transactions.rb:291:in `block in save!'
activerecord (4.2.3) lib/active_record/transactions.rb:351:in `block in with_transaction_returning_status'
activerecord (4.2.3) lib/active_record/connection_adapters/abstract/database_statements.rb:213:in `block in transaction'
activerecord (4.2.3) lib/active_record/connection_adapters/abstract/transaction.rb:184:in `within_new_transaction'
activerecord (4.2.3) lib/active_record/connection_adapters/abstract/database_statements.rb:213:in `transaction'
activerecord (4.2.3) lib/active_record/transactions.rb:220:in `transaction'
activerecord (4.2.3) lib/active_record/transactions.rb:348:in `with_transaction_returning_status'
activerecord (4.2.3) lib/active_record/transactions.rb:291:in `save!'
activerecord (4.2.3) lib/active_record/persistence.rb:51:in `create!'
doorkeeper (2.2.1) lib/doorkeeper/models/access_token_mixin.rb:76:in `find_or_create_for'
doorkeeper (2.2.1) lib/doorkeeper/oauth/request_concern.rb:33:in `find_or_create_access_token'
doorkeeper (2.2.1) lib/doorkeeper/oauth/password_access_token_request.rb:30:in `before_successful_response'
doorkeeper (2.2.1) lib/doorkeeper/oauth/request_concern.rb:7:in `authorize'
doorkeeper (2.2.1) lib/doorkeeper/request/password.rb:19:in `authorize'
doorkeeper (2.2.1) app/controllers/doorkeeper/tokens_controller.rb:42:in `authorize_response'
doorkeeper (2.2.1) app/controllers/doorkeeper/tokens_controller.rb:4:in `create'

即使我使用POST /oauth/revoke撤销令牌，除了在oauth_access_tokens中的撤销时间戳之外，一切都不会改变。这很奇怪。

我进行了一些调查，并在doorkeeper gem（access_token_mixin.rb）中找到了一段代码：

def find_or_create_for(application, resource_owner_id, scopes, expires_in, use_refresh_token)
        if Doorkeeper.configuration.reuse_access_token
          access_token = matching_token_for(application, resource_owner_id, scopes)
          if access_token && !access_token.expired?
            return access_token
          end
        end
        create!(
          application_id:    application.try(:id),
          resource_owner_id: resource_owner_id,
          scopes:            scopes.to_s,
          expires_in:        expires_in,
          use_refresh_token: use_refresh_token
        )
      end

因此，错误出现在create!方法中，该方法指出我们尝试添加重复项（在堆栈跟踪中）。如果我在Doorkeeper.configure中设置reuse_access_token，则可以解决问题。但是，我会在每次授权后收到相同的令牌，这非常不安全，我理解。是的，如果我手动从oauth_access_tokens中删除令牌，那么我将能够进行身份验证。

那么问题出在哪里呢？

我的Doorkeeper配置：

Doorkeeper.configure do
  # Change the ORM that doorkeeper will use.
  # Currently supported options are :active_record, :mongoid2, :mongoid3,
  # :mongoid4, :mongo_mapper
  orm :active_record

  resource_owner_authenticator do
    current_user || env['warden'].authenticate!(:scope => :user)
  end

  resource_owner_from_credentials do |routes|
    request.params[:user] = {:email => request.params[:username], :password => request.params[:password]}
    request.env["devise.allow_params_authentication"] = true
    user = request.env['warden'].authenticate!(:scope => :user)
    env['warden'].logout
    user
  end

  access_token_generator "Doorkeeper::JWT"
end

Doorkeeper.configuration.token_grant_types << "password"

Doorkeeper::JWT.configure do
#JWT config
end

路由：

require 'api_constraints'

Rails.application.routes.draw do
  use_doorkeeper
  devise_for :users
  namespace :api, defaults: {format: :json}, constraints: { subdomain: 'api' }, path: '/' do
    scope module: :v1, constraints: ApiConstraints.new(version: 1, default: true) do
      resources :users, :only => [:show, :create, :update]

      get '/me' => "credentials#me"
    end
  end
end

- cheyuriy

Answer 1

如果您想找到答案，那么就要提出一个问题。

问题出在 Doorkeeper::JWT 令牌的默认实现上。它的负载中没有任何随机性，因此对于每个用户的身份验证，它始终是相同的。因此我添加了以下内容：

Doorkeeper::JWT.configure do
  token_payload do |opts|
    user = User.find(opts[:resource_owner_id])
    {
      iss: "myapp",  #this
      iat: DateTime.current.utc.to_i,   #this
      rnd: SecureRandom.hex,   #and this

      user: {
        id: user.id,
        email: user.email
      }
    }
  end

  secret_key "key"

  encryption_method :hs256
end

它能够正常工作。

- cheyuriy

Answer 2

我没有足够的声望在选择的答案上发表评论，所以我会添加另一个答案来建议改进。

不要创建可能会发生名称冲突的 "rnd" 声明，而应使用保留的 "jti" 声明，因为它旨在为JWT提供唯一标识符。我还建议使用UUID而不是Hex作为 "jti" 值。

Doorkeeper::JWT.configure do
  token_payload do |opts|
    user = User.find(opts[:resource_owner_id])
    {
      iss: "myapp",
      iat: DateTime.current.utc.to_i,
      jti: SecureRandom.uuid,

      user: {
        id: user.id,
        email: user.email
      }
    }
  end

  secret_key "key"

  encryption_method :hs256
end

您可以在这里阅读有关JWT保留声明的更多信息。

- kevinsapp