init project

app/libs/wechat/client.rb

@@ -0,0 +1,74 @@
+class Wechat::Client
+  BASE_SITE = 'https://api.weixin.qq.com'.freeze
+
+  attr_reader :appid, :secret
+
+  def initialize(appid, secret)
+    @appid  = appid
+    @secret = secret
+  end
+
+  def access_token
+    # 7200s 有效时间
+    Rails.cache.fetch(access_token_cache_key, expires_in: 100.minutes) do
+      result = request(:get, '/cgi-bin/token', appid: appid, secret: secret, grant_type: 'client_credential')
+      result['access_token']
+    end
+  end
+
+  def refresh_access_token
+    Rails.cache.delete(access_token_cache_key)
+    access_token
+  end
+
+  def jsapi_ticket
+    # 7200s 有效时间
+    Rails.cache.fetch(jsapi_ticket_cache_key, expires_in: 100.minutes) do
+      result = request(:get, '/cgi-bin/ticket/getticket', access_token: access_token, type: 'jsapi')
+      result['ticket']
+    end
+  end
+
+  def refresh_jsapi_ticket
+    Rails.cache.delete(jsapi_ticket_cache_key)
+    jsapi_ticket
+  end
+
+  def jscode2session(code)
+    request(:get, '/sns/jscode2session', appid: appid, secret: secret, js_code: code, grant_type: 'authorization_code')
+  end
+
+  def access_token_cache_key
+    "#{base_cache_key}/access_token"
+  end
+
+  def jsapi_ticket_cache_key
+    "#{base_cache_key}/jsapi_ticket"
+  end
+
+  def base_cache_key
+    "wechat/#{appid}"
+  end
+
+  private
+
+  def request(method, url, **params)
+    Rails.logger.info("[wechat] request: #{method} #{url} #{params.except(:secret).inspect}")
+
+    client = Faraday.new(url: BASE_SITE)
+    response = client.public_send(method, url, params)
+    result = JSON.parse(response.body)
+
+    Rails.logger.info("[wechat] response:#{response.status} #{result.inspect}")
+
+    if response.status != 200
+      raise Wechat::Error.parse(result)
+    end
+
+    if result['errcode'].present? && result['errcode'].to_i.nonzero?
+      raise Wechat::Error.parse(result)
+    end
+
+    result
+  end
+end

app/libs/wechat/error.rb

@@ -0,0 +1,14 @@
+class Wechat::Error < StandardError
+  attr_reader :code
+
+  def initialize(code, message)
+    super message
+    @code = code
+  end
+
+  class << self
+    def parse(result)
+      new(result['errcode'], result['errmsg'])
+    end
+  end
+end

app/libs/wechat/official_account.rb

@@ -0,0 +1,17 @@
+class Wechat::OfficialAccount
+  class << self
+    attr_accessor :appid, :secret
+
+    delegate :access_token, :jsapi_ticket, to: :client
+
+    def js_sdk_signature(url, noncestr, timestamp)
+      data = { jsapi_ticket: jsapi_ticket, noncestr: noncestr, timestamp: timestamp, url: url }
+      str = data.map { |k, v| "#{k}=#{v}" }.join('&')
+      Digest::SHA1.hexdigest(str)
+    end
+
+    def client
+      @_client ||= Wechat::Client.new(appid, secret)
+    end
+  end
+end

app/libs/wechat/weapp.rb

@@ -0,0 +1,49 @@
+class Wechat::Weapp
+  class << self
+    attr_accessor :appid, :secret
+
+    delegate :access_token, :jscode2session, to: :client
+
+    def client
+      @_client ||= Wechat::Client.new(appid, secret)
+    end
+
+    def session_key(openid)
+      Rails.cache.read(session_key_cache_key(openid))
+    end
+
+    def write_session_key(openid, session_key)
+      Rails.cache.write(session_key_cache_key(openid), session_key)
+    end
+
+    def verify?(openid, str, signature)
+      session_key = session_key(openid)
+      Digest::SHA1.hexdigest("#{str}#{session_key}") == signature
+    end
+
+    def decrypt(session_key, encrypted_data, iv)
+      session_key = Base64.decode64(session_key)
+      encrypted_data = Base64.decode64(encrypted_data)
+      iv = Base64.decode64(iv)
+
+      cipher = OpenSSL::Cipher::AES.new(128, :CBC)
+      cipher.decrypt
+      cipher.padding = 0
+      cipher.key = session_key
+      cipher.iv  = iv
+      Rails.logger.info("[Weapp] encrypted_data: #{encrypted_data}")
+      data = cipher.update(encrypted_data) << cipher.final
+      Rails.logger.info("[Weapp] data: #{data}")
+      result = JSON.parse(data[0...-data.last.ord])
+
+      raise Wechat::Error.new(-1, '解密错误') if result.dig('watermark', 'appid') != appid
+      result
+    end
+
+    private
+
+    def session_key_cache_key(openid)
+      "weapp:#{appid}:#{openid}:session_key"
+    end
+  end
+end