我尝试使用TLS 1.2访问第三方API，但获得有效证书的SSL错误事件

Ruby版本：

ruby 2.3.0p0 (2015-12-25 revision 53290) [x86_64-linux]

Rails版本：

Rails 4.2.5

验证码：

ua = Net::HTTP.new(SERVER, 443)
    ua.instance_eval {
      @ssl_context = OpenSSL::SSL::SSLContext.new
      options = OpenSSL::SSL::OP_NO_SSLv2 | OpenSSL::SSL::OP_NO_SSLv3
      if OpenSSL::SSL.const_defined?('OP_NO_COMPRESSION')
        options |= OpenSSL::SSL::OP_NO_COMPRESSION
      end
      @ssl_context.set_params({options: options})
    }
   # ua.instance_eval { @ssl_context = OpenSSL::SSL::SSLContext.new(:TLSv1_2) }
    ua.use_ssl = true

    # Checks presence of CA certificate
    if File.directory?(RootCA)
      ua.ca_path = RootCA
      ua.verify_mode = OpenSSL::SSL::VERIFY_PEER
      ua.verify_depth = 3
    else
      puts "Invalid CA certificates directory. Exiting..."
      exit
    end

错误：

OpenSSL::SSL::SSLError: SSL_connect returned=1 errno=0 state=SSLv3 read server certificate B: certificate verify failed
    from /home/cp/.rbenv/versions/2.3.0/lib/ruby/2.3.0/net/http.rb:933:in `connect_nonblock'
    from /home/cp/.rbenv/versions/2.3.0/lib/ruby/2.3.0/net/http.rb:933:in `connect'
    from /home/cp/.rbenv/versions/2.3.0/lib/ruby/2.3.0/net/http.rb:863:in `do_start'
    from /home/cp/.rbenv/versions/2.3.0/lib/ruby/2.3.0/net/http.rb:852:in `start'
    from /home/cp/.rbenv/versions/2.3.0/lib/ruby/2.3.0/net/http.rb:1398:in `request'
    from /home/cp/.rbenv/versions/2.3.0/lib/ruby/2.3.0/net/http.rb:1421:in `send_entity'
    from /home/cp/.rbenv/versions/2.3.0/lib/ruby/2.3.0/net/http.rb:1209:in `post'