在CentOS 下布署ROR环境时， gem update 指令报如下错误

/opt/rubies/ruby-1.9.3-p484/lib/ruby/1.9.1/rubygems/custom_require.rb:36:in `require': /opt/rubies/ruby-1.9.3-p484/lib/ruby/1.9.1/x86_64-linux/openssl.so: undefined symbol: EC_GROUP_new_curve_GF2m - /opt/rubies/ruby-1.9.3-p484/lib/ruby/1.9.1/x86_64-linux/openssl.so (LoadError)
from /opt/rubies/ruby-1.9.3-p484/lib/ruby/1.9.1/rubygems/custom_require.rb:36:in `require'
from /opt/rubies/ruby-1.9.3-p484/lib/ruby/1.9.1/openssl.rb:17:in `<top (required)>'
from /opt/rubies/ruby-1.9.3-p484/lib/ruby/1.9.1/rubygems/custom_require.rb:36:in `require'
from /opt/rubies/ruby-1.9.3-p484/lib/ruby/1.9.1/rubygems/custom_require.rb:36:in `require'

应该是 openssl 版本问题所致，解决方案如下：
Installing OpenSSL anywhere besides /usr puts the libraries in the expected lib instead of lib64. (Don’t ask me why… dunno.) This may be the more maintainable solution as it lets you avoid hacking up the Makefile. This is also the solution RVM uses when running rvm pkg install openssl. Thus, to install both OpenSSL and Ruby (in /opt), you may run commands something like these (I run as sudo bash):
Install OpenSSL:
cd /opt/local
wget http://www.openssl.org/source/openssl-1.0.1f.tar.gz
tar -xzf openssl-1.0.1f.tar.gz
cd openssl-1.0.1f
./config --prefix=/opt/local shared no-asm zlib > openssl_config.log
make > openssl_make.log
make install > openssl_install.log
(The shared switch is required for Ruby to install without error, the no-asm switch helps get rid of a Make warning but does not appear to be required, and zlib and other switches are optional.)
Optional, update openssl certs:
cd /opt/local/ssl
wget http://curl.haxx.se/ca/cacert.pem
mv cacert.pem cert.pem
cd /opt
Back to Ruby: 连接指定的OpenSSL 安装
ruby-install ruby 1.9.3-p545 -- --with-openssl-dir=/opt/local
或者RVM环境下：
rvm install 1.9.3 --with-openssl-dir=/opt/local
问题解决， gem update 成功！