身在天朝，用了國外的代碼托管服務，會有些煩惱的。
網速慢就不說了，如果啟用了二次驗證，短信收不到那就悲催了。
之前的都能收到短信的，突然間嘗試了很多天都不行，聯系github的客服，幾次的答復如下：
第一封郵件發給Github
Hi,
When I login , after input username and password, need input Authentication Code, I input it, show [Two-factor Authentication failed]
I click [Re-send the code], but this page is 404 as follow:
I can’t login for several days, please help me quickly!
My username in GitHub is “*******”.
回復：
Hi Kang,
The 404 sounds like a Javascript error.
Can you try updating Chrome to the current release and double checking that Javascript is enabled in your browser settings?
Instructions for enabling JS can be found here:
http://enable-javascript.com/#chrome
Cheers,
John
既然這么說，咱換成IE吧，居然不提示404，那就這么滴吧，可是還收不到短信。
第二封郵件
Hi,
Thanks for your kindly support!
I use IE, no 404 error again, show " Your authentication code has been sent. ", but I don't get sms.
My phone number is "+86 xxx" and github username is "xxxx".
BTW, at 2/17/2014 , I got sms about two-factor authentication code successfully, but can't get sms now and phone number is same.
回復：
The authentication codes are being sent out, but we do hear sporadic reports of codes being delayed or dropped by Chinese carriers.
Do you have the two-factor authentication recovery codes for your account? They were presented to you when you first enabled 2FA. You should be able to user one of them to regain access to your account by following the "Forgot your phone?" on the 2FA page after entering your username and password
Once you have regained access to your account you might want to consider switching to an OTP authentication application for 2FA. More details are available here:
Thanks,
John
他說驗證碼都發了，但是確實受到零星的報告說 短信被丟棄或者被延遲發送了。
然后讓我去找那個 二次驗證的恢復碼，我哪有那玩意啊。
為此我還聯系了中國移動，讓他們查查發送給我的短信是否被攔截了，態度蠻好的，結果你懂的。
我自己也查看了之前收到的短信號碼，發現每次都不一樣，有的是是133開頭的，屬地為浙江某地，還有時候是香港的號碼。
一共是十幾次，每次短信號碼都不一樣，這樣子搞，能行嗎？
第三封郵件
Sorry to tell you, I can't find recovery codes, any other way?
Our other member can't receiver sms too.
回復：
Hello kang,
We recommend using one of the 2FA recovery codes you were asked to save when you enabled 2FA on your account.
If you haven't saved your recovery codes in a safe place, you can verify your identity using an SSH key you have added to your account. To do this, please run the following command on the computer where your SSH key exists, and send us the full output:
ssh -T git@github.com verify
If you can verify your identity, we can disable 2FA on your account so you can sign in again.
Sincerely,
Daisuke
人家還是推薦用二次驗證的恢復碼，我真沒有啊。
於是乎，嘗試 ssh驗證。
第一次總是那么倒霉，不成功啊。
找到了這篇文章，又琢磨了很久
http://rangercyh.blog.51cto.com/1444712/749490
確保網絡正常，能fanqiang的就fan一下吧。
第四封郵件：
Hi,
Thank you for your kindly support!
>>please run the following command on the computer where your SSH key exists, and send us the full output:
As follow:
E:\Android\github\AndroidLearning [master +9 ~5 -0 !]> ssh -t git@github.com verify
Warning: Permanently added
'[ssh.github.com]:443,[192.30.252.148]:443' (RSA) tothe list of known hosts.
Please provide the following verification token to GitHub Support.
BAh7BzoKbG9naW5JIhB4aWFva2F××××××××××××××××××××××××××××××××××××××××××××××iZg==
Connection to ssh.github.com closed.
終於能登錄了，扯了好幾天，不容易吶。
GitHub確實是個好東西，可是有時候真的很無奈。
另外還有一個app驗證的方式，沒試過，后面再研究一下。