From a3a62f87e144be31b9ca8ad6415b207f43f4e126 Mon Sep 17 00:00:00 2001 From: emboss Date: Fri, 5 Jul 2013 21:08:04 +0000 Subject: * lib/openssl/ssl.rb: Fix SSL client connection crash for SAN marked critical. The patch for CVE-2013-4073 caused SSL crash when a SSL server returns the certificate that has critical SAN value. X509 extension could include 2 or 3 elements in it: [id, criticality, octet_string] if critical, [id, octet_string] if not. Making sure to pick the last element of X509 extension and use it as SAN value. [ruby-core:55685] [Bug #8575] Thank you @nahi for providing the patch! git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@41805 b2dd03c8-39d4-4d8f-98ff-823fe69b080e --- ChangeLog | 17 +++++++++++++++++ ext/openssl/lib/openssl/ssl.rb | 2 +- test/openssl/test_ssl.rb | 27 +++++++++++++++++---------- 3 files changed, 35 insertions(+), 11 deletions(-) diff --git a/ChangeLog b/ChangeLog index d6fd2ca577..2cb8c11402 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,20 @@ +Sat Jul 6 06:06:16 2013 Martin Bosslet + + * lib/openssl/ssl.rb: Fix SSL client connection crash for SAN marked + critical. + The patch for CVE-2013-4073 caused SSL crash when a SSL server returns + the certificate that has critical SAN value. X509 extension could + include 2 or 3 elements in it: + + [id, criticality, octet_string] if critical, + [id, octet_string] if not. + + Making sure to pick the last element of X509 extension and use it as + SAN value. + [ruby-core:55685] [Bug #8575] + + Thank you @nahi for providing the patch! + Sat Jul 6 04:49:38 2013 Aaron Patterson * ext/psych/lib/psych/visitors/yaml_tree.rb: register time objects so diff --git a/ext/openssl/lib/openssl/ssl.rb b/ext/openssl/lib/openssl/ssl.rb index 04eb59246c..741274a5f9 100644 --- a/ext/openssl/lib/openssl/ssl.rb +++ b/ext/openssl/lib/openssl/ssl.rb @@ -98,7 +98,7 @@ module OpenSSL should_verify_common_name = true cert.extensions.each{|ext| next if ext.oid != "subjectAltName" - id, ostr = OpenSSL::ASN1.decode(ext.to_der).value + ostr = OpenSSL::ASN1.decode(ext.to_der).value.last sequence = OpenSSL::ASN1.decode(ostr.value) sequence.value.each{|san| case san.tag diff --git a/test/openssl/test_ssl.rb b/test/openssl/test_ssl.rb index daaaa0a1e4..a3100a8c50 100644 --- a/test/openssl/test_ssl.rb +++ b/test/openssl/test_ssl.rb @@ -338,25 +338,32 @@ class OpenSSL::TestSSL < OpenSSL::SSLTestCase end def test_verify_certificate_identity - # creating NULL byte SAN certificate + [true, false].each do |criticality| + cert = create_null_byte_SAN_certificate(criticality) + assert_equal(false, OpenSSL::SSL.verify_certificate_identity(cert, 'www.example.com')) + assert_equal(true, OpenSSL::SSL.verify_certificate_identity(cert, 'www.example.com\0.evil.com')) + assert_equal(false, OpenSSL::SSL.verify_certificate_identity(cert, '192.168.7.255')) + assert_equal(true, OpenSSL::SSL.verify_certificate_identity(cert, '192.168.7.1')) + assert_equal(false, OpenSSL::SSL.verify_certificate_identity(cert, '13::17')) + assert_equal(true, OpenSSL::SSL.verify_certificate_identity(cert, '13:0:0:0:0:0:0:17')) + end + end + + # Create NULL byte SAN certificate + def create_null_byte_SAN_certificate(critical = false) ef = OpenSSL::X509::ExtensionFactory.new cert = OpenSSL::X509::Certificate.new cert.subject = OpenSSL::X509::Name.parse "/DC=some/DC=site/CN=Some Site" - ext = ef.create_ext('subjectAltName', 'DNS:placeholder,IP:192.168.7.1,IP:13::17') + ext = ef.create_ext('subjectAltName', 'DNS:placeholder,IP:192.168.7.1,IP:13::17', critical) ext_asn1 = OpenSSL::ASN1.decode(ext.to_der) san_list_der = ext_asn1.value.reduce(nil) { |memo,val| val.tag == 4 ? val.value : memo } san_list_asn1 = OpenSSL::ASN1.decode(san_list_der) san_list_asn1.value[0].value = 'www.example.com\0.evil.com' - ext_asn1.value[1].value = san_list_asn1.to_der + pos = critical ? 2 : 1 + ext_asn1.value[pos].value = san_list_asn1.to_der real_ext = OpenSSL::X509::Extension.new ext_asn1 cert.add_extension(real_ext) - - assert_equal(false, OpenSSL::SSL.verify_certificate_identity(cert, 'www.example.com')) - assert_equal(true, OpenSSL::SSL.verify_certificate_identity(cert, 'www.example.com\0.evil.com')) - assert_equal(false, OpenSSL::SSL.verify_certificate_identity(cert, '192.168.7.255')) - assert_equal(true, OpenSSL::SSL.verify_certificate_identity(cert, '192.168.7.1')) - assert_equal(false, OpenSSL::SSL.verify_certificate_identity(cert, '13::17')) - assert_equal(true, OpenSSL::SSL.verify_certificate_identity(cert, '13:0:0:0:0:0:0:17')) + cert end def test_tlsext_hostname -- cgit v1.2.3