步骤：
1.

gem sources --remove https://rubygems.org/

2.

gem sources -a https://ruby.taobao.org/
Error fetching https://ruby.taobao.org/:
        SSL_connect returned=1 errno=0 state=SSLv3 read server certificate B: ce
rtificate verify failed (https://rubygems-china.oss-cn-hangzhou.aliyuncs.com/spe
cs.4.8.gz)

3.

gem sources -l
*** CURRENT SOURCES ***

问题出处：
http://stackoverflow.com/questions/4528101/ssl-connect-returned-1-errno-0-state-sslv3-read-server-certificate-b-certificat

https://gist.github.com/fnichol/867550

I had this same issue while working on a Ruby project. I am using Windows 7 64bit.

I resolved this by:

Downloading the cacert.pem file from http://curl.haxx.se/ca/cacert.pem.
Saved that file to C:/RubyCertificates/cacert.pem
Then set my environmental variable "SSL_CERT_FILE" to "C:/RubyCertificates/cacert.pem"
source: https://gist.github.com/fnichol/867550

证书地址：http://curl.haxx.se/ca/cacert.pem

按照上面这位网友的方法配置了环境变量如下图

再次执行gem sources -a https://ruby.taobao.org/
报错依旧

有谁遇到过，还是我的环境变量没有配置对呢？