Docs.google.com Connection Reset Solution

From: http://www.zreading.cn/ican/2010/05/docs-google-com/

I. Why can I access it without encryption?

1. Google Docs is often used to disseminate illegal information

Google Docs has always been a tool for transmitting non-harmonious information, because it provides HTTPS access, encrypted transmission of information, and third parties cannot simply eavesdrop. Some illegal documents that use Google Docs are frequently circulated on Twitter.

A master's thesis from a university in Shanghai has been circulating on the internet some time ago. This paper reveals how freegate, an illegal software, gets the latest proxy list. The most important channel is Google Docs, since gdocs can be normally accessed in mainland China, freegate can update DNS and proxy lists in real time to escape the blocking. Freegate uses HTTPS to obtain the file information in Google Docs.

2. New interception methods

Similar to Google Docs, https is not accessible, but HTTP is accessible. The reason for using this method is 3:

(1) Google Docs is a common service and cannot be completely blocked

(2) Google has many IP addresses that cannot be completely blocked. If they are completely blocked, they will affect Google's normal use.

(3) Illegal Information in Google Docs must be blocked.

These three reasons have promoted the development of new interception methods. According to speculation, this method is like this: when the client sends an encrypted DNS resolution request, the DNS monitoring end immediately sends a reset signal once it finds that the request is from Google Docs. For general unencrypted DNS requests, the DNS monitoring end does not work, and the rest of the monitoring work is carried out by the normal review system.

3. Benefits of new interception methods

(1) it effectively prevents the spread of illegal information on Google Docs and enables normal use of Google Docs

(2) completely blocks illegal software such as freegate

(3) When users stop using HTTPS and use HTTP for access, the information is transmitted in plain text, and all content enters the review system for review. Illegal information cannot be transmitted.

Ii. solution 1: opendns

Since HTTPS access is reset when a request is sent to DNS, an easy-to-think solution is to change the DNS that does not review the DNS request. Opendns is a common choice. It is easy to use. Set the computer's DNS:

208.67.222.222

208.67.220.220

If you need to switch DNS frequently, you can use netsetman introduced in "8 Free Software for improving windows efficiency" to switch DNS.

However, opendns is a foreign DNS and the connection speed is slow. We may consider another solution.

Iii. solution 2: Custom hosts(I use this method)

Adding the resolution IP address of Google docs in the hosts directly bypasses the DNS query, so that Google Docs with HTTPS can be used normally.

Hosts file location:

1. Windows: c: \ windows \ system32 \ drivers \ etc \ hosts

2. Linux:/etc/hosts

Open the hosts file in notepad and add the following content to the top of the hosts file:

209.85.225.101 docs.google.com

74.125.127.100 writely.google.com

74.125.127.139 spreadsheets.google.com

Save the hosts and restart the browser. Then Google docs in https mode can be accessed normally.

What if Gmail also encounters Google docs? In the same way, add the Gmail IP address to the hosts file. For ease of use, I will provide the Google service with HTTPS and its IP address list as follows:

209.85.147.109 pop.gmail.com

209.85.147.109 smtp.gmail.com

66.102.7.19 mail.google.com

209.85.225.101 docs.google.com

209.85.225.102 groups.google.com

74.125.127.139 spreadsheets.google.com

74.125.127.100 services.google.com

74.125.127.100 writely.google.com

74.125.127.100 sites.google.com

209.85.225.104 reader.google.com

74.125.127.101 calendar.google.com