Backport r34482 from trunk. See #5353

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_8@34485 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

3 files changed, 64 insertions, 13 deletions

diff --git a/ChangeLog b/ChangeLog
index cfc05d33a2..3f77135599 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,34 @@
+Wed Feb  8 14:06:59 2012  Hiroshi Nakamura  <nahi@ruby-lang.org>
+
+	* ext/openssl/ossl_ssl.c: Add SSL constants and allow to unset SSL
+	  option to prevent BEAST attack. See [Bug #5353].
+
+	  In OpenSSL, OP_DONT_INSERT_EMPTY_FRAGMENTS is used to prevent
+	  TLS-CBC-IV vulunerability described at
+	  http://www.openssl.org/~bodo/tls-cbc.txt
+	  It's known issue of TLSv1/SSLv3 but it attracts lots of attention
+	  these days as BEAST attack. (CVE-2011-3389)
+
+	  Until now ossl sets OP_ALL at SSLContext allocation and call
+	  SSL_CTX_set_options at connection.  SSL_CTX_set_options updates the
+	  value by using |= so bits set by OP_ALL cannot be unset afterwards.
+
+	  This commit changes to call SSL_CTX_set_options only 1 time for each
+	  SSLContext. It sets the specified value if SSLContext#options= are
+	  called and sets OP_ALL if not.
+
+	  To help users to unset bits in OP_ALL, this commit also adds several
+	  constant to SSL such as
+	  OpenSSL::SSL::OP_DONT_INSERT_EMPTY_FRAGMENTS.  These constants were
+	  not exposed in Ruby because there's no way to unset bits in OP_ALL
+	  before.
+
+	  Following is an example to enable 0/n split for BEAST prevention.
+
+	    ctx.options = OP_ALL & ~OP_DONT_INSERT_EMPTY_FRAGMENTS
+
+	* test/openssl/test_ssl.rb: Test above option exists.
+
 Sun Jun 26 17:52:32 2011  Nobuhiro Iwamatsu  <iwamatsu@nigauri.org>
 
 	* ext/openssl/ossl_ssl.c: By trunk@31346, function check of SSLv2 is executed.
diff --git a/ext/openssl/ossl_ssl.c b/ext/openssl/ossl_ssl.c
index 138b405a13..078f88acdc 100644
--- a/ext/openssl/ossl_ssl.c
+++ b/ext/openssl/ossl_ssl.c
@@ -148,7 +148,6 @@ ossl_sslctx_s_alloc(VALUE klass)
         ossl_raise(eSSLError, "SSL_CTX_new:");
     }
     SSL_CTX_set_mode(ctx, SSL_MODE_ENABLE_PARTIAL_WRITE);
-    SSL_CTX_set_options(ctx, SSL_OP_ALL);
     return Data_Wrap_Struct(klass, 0, ossl_sslctx_free, ctx);
 }
 
@@ -630,7 +629,11 @@ ossl_sslctx_setup(VALUE self)
     if(!NIL_P(val)) SSL_CTX_set_verify_depth(ctx, NUM2LONG(val));
 
     val = ossl_sslctx_get_options(self);
-    if(!NIL_P(val)) SSL_CTX_set_options(ctx, NUM2LONG(val));
+    if(!NIL_P(val)) {
+    	SSL_CTX_set_options(ctx, NUM2LONG(val));
+    } else {
+	SSL_CTX_set_options(ctx, SSL_OP_ALL);
+    }
     rb_obj_freeze(self);
 
     val = ossl_sslctx_get_sess_id_ctx(self);
@@ -1536,18 +1539,20 @@ Init_ossl_ssl()
     ossl_ssl_def_const(VERIFY_PEER);
     ossl_ssl_def_const(VERIFY_FAIL_IF_NO_PEER_CERT);
     ossl_ssl_def_const(VERIFY_CLIENT_ONCE);
-    /* Not introduce constants included in OP_ALL such as...
-     * ossl_ssl_def_const(OP_MICROSOFT_SESS_ID_BUG);
-     * ossl_ssl_def_const(OP_NETSCAPE_CHALLENGE_BUG);
-     * ossl_ssl_def_const(OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG);
-     * ossl_ssl_def_const(OP_SSLREF2_REUSE_CERT_TYPE_BUG);
-     * ossl_ssl_def_const(OP_MICROSOFT_BIG_SSLV3_BUFFER);
-     * ossl_ssl_def_const(OP_MSIE_SSLV2_RSA_PADDING);
-     * ossl_ssl_def_const(OP_SSLEAY_080_CLIENT_DH_BUG);
-     * ossl_ssl_def_const(OP_TLS_D5_BUG);
-     * ossl_ssl_def_const(OP_TLS_BLOCK_PADDING_BUG);
-     * ossl_ssl_def_const(OP_DONT_INSERT_EMPTY_FRAGMENTS);
+    /* Introduce constants included in OP_ALL.  These constants are mostly for
+     * unset some bits in OP_ALL such as;
+     *   ctx.options = OP_ALL & ~OP_DONT_INSERT_EMPTY_FRAGMENTS
      */
+    ossl_ssl_def_const(OP_MICROSOFT_SESS_ID_BUG);
+    ossl_ssl_def_const(OP_NETSCAPE_CHALLENGE_BUG);
+    ossl_ssl_def_const(OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG);
+    ossl_ssl_def_const(OP_SSLREF2_REUSE_CERT_TYPE_BUG);
+    ossl_ssl_def_const(OP_MICROSOFT_BIG_SSLV3_BUFFER);
+    ossl_ssl_def_const(OP_MSIE_SSLV2_RSA_PADDING);
+    ossl_ssl_def_const(OP_SSLEAY_080_CLIENT_DH_BUG);
+    ossl_ssl_def_const(OP_TLS_D5_BUG);
+    ossl_ssl_def_const(OP_TLS_BLOCK_PADDING_BUG);
+    ossl_ssl_def_const(OP_DONT_INSERT_EMPTY_FRAGMENTS);
     ossl_ssl_def_const(OP_ALL);
 #if defined(SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION)
     ossl_ssl_def_const(OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION);
diff --git a/test/openssl/test_ssl.rb b/test/openssl/test_ssl.rb
index 0bcf754b00..e64ce44071 100644
--- a/test/openssl/test_ssl.rb
+++ b/test/openssl/test_ssl.rb
@@ -1032,6 +1032,21 @@ class OpenSSL::TestSSL < Test::Unit::TestCase
       end
     end
   end
+
+  def test_unset_OP_ALL
+    ctx_proc = Proc.new { |ctx|
+      ctx.options = OpenSSL::SSL::OP_ALL & ~OpenSSL::SSL::OP_DONT_INSERT_EMPTY_FRAGMENTS
+    }
+    start_server(PORT, OpenSSL::SSL::VERIFY_NONE, true, :ctx_proc => ctx_proc){|server, port|
+      sock = TCPSocket.new("127.0.0.1", port)
+      ssl = OpenSSL::SSL::SSLSocket.new(sock)
+      ssl.sync_close = true
+      ssl.connect
+      ssl.puts('hello')
+      assert_equal("hello\n", ssl.gets)
+      ssl.close
+    }
+  end
 end
 
 end