ssl: fix conflict of options in SSLContext#set_params

Make SSLContext#set_params call #options= first.

SSLContext#set_params by default disables SSL 2.0 and SSL 3.0 by calling
SSLContext#min_version=. After that, it sets the SSL option flags by
calling SSLContext#options=.

This is problematic when built with OpenSSL before 1.1.0 because
SSLContext#min_version= achieves its goal using the SSL_OP_NO_{SSL,TLS}*
options. Since the subsequent SSLContext#options= call replaces the
flags rather than OR together, this results in effectively disabling
min_version setting in SSLContext::DEFAULT_PARAMS.

The issue was first fixed in Ruby trunk tree, as part of r60310 ("fix
OpenSSL::SSL::SSLContext#min_version doesn't work", 2017-10-21).

lib/openssl/ssl.rb

@@ -136,6 +136,7 @@ def initialize(version = nil)
       # used.
       def set_params(params={})
         params = DEFAULT_PARAMS.merge(params)
+        self.options = params.delete(:options) # set before min_version/max_version
         params.each{|name, value| self.__send__("#{name}=", value) }
         if self.verify_mode != OpenSSL::SSL::VERIFY_NONE
           unless self.ca_file or self.ca_path or self.cert_store

test/test_ssl.rb

@@ -811,6 +811,24 @@ def check_supported_protocol_versions
     supported
   end
 
+  def test_set_params_min_version
+    supported = check_supported_protocol_versions
+    store = OpenSSL::X509::Store.new
+    store.add_cert(@ca_cert)
+
+    if supported.include?(OpenSSL::SSL::SSL3_VERSION)
+      # SSLContext#set_params properly disables SSL 3.0 by default
+      ctx_proc = proc { |ctx|
+        ctx.min_version = ctx.max_version = OpenSSL::SSL::SSL3_VERSION
+      }
+      start_server(ctx_proc: ctx_proc, ignore_listener_error: true) { |port|
+        ctx = OpenSSL::SSL::SSLContext.new
+        ctx.set_params(cert_store: store, verify_hostname: false)
+        assert_handshake_error { server_connect(port, ctx) { } }
+      }
+    end
+  end
+
   def test_minmax_version
     supported = check_supported_protocol_versions