From 0234bcfd19aa0a7b4152809c13554144b7322f41 Mon Sep 17 00:00:00 2001 From: emboss Date: Thu, 9 Feb 2012 17:04:41 +0000 Subject: * backport r34482 from trunk * 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. git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_9_3@34524 b2dd03c8-39d4-4d8f-98ff-823fe69b080e --- ext/openssl/ossl_ssl.c | 32 +++++++++++++++++++------------- 1 file changed, 19 insertions(+), 13 deletions(-) (limited to 'ext') diff --git a/ext/openssl/ossl_ssl.c b/ext/openssl/ossl_ssl.c index 3769633468..2b52bf07c3 100644 --- a/ext/openssl/ossl_ssl.c +++ b/ext/openssl/ossl_ssl.c @@ -151,7 +151,6 @@ ossl_sslctx_s_alloc(VALUE klass) ossl_raise(eSSLError, "SSL_CTX_new:"); } SSL_CTX_set_mode(ctx, mode); - SSL_CTX_set_options(ctx, SSL_OP_ALL); return Data_Wrap_Struct(klass, 0, ossl_sslctx_free, ctx); } @@ -643,7 +642,12 @@ ossl_sslctx_setup(VALUE self) if(!NIL_P(val)) SSL_CTX_set_verify_depth(ctx, NUM2INT(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); @@ -1966,18 +1970,20 @@ 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); -- cgit v1.2.3