1 #

     2 # This patch contains the fixes for CVE-2013-4073 (NULL bytes in subjectAltName

     3 # not correctly interpreted).

     4 # The patch was taken from:

     5 # https://code.launchpad.net/~heimes/pyopenssl/pyopenssl/+merge/179673 

     6 # and modified to fit the the 0.13 release code (original fix was based off tip

     7 # code in pyopenssl repo).

     8 #

     9 --- pyOpenSSL-0.13/ChangeLog	2011-09-02 08:46:13.000000000 -0700

    10 +++ pyOpenSSL-0.13/ChangeLog	2013-08-26 14:40:43.941191227 -0700

    11 @@ -1,3 +1,9 @@

    12 +2013-08-11 Christian Heimes <[email protected]>

    13 +

    14 +	* OpenSSL/crypto/x509ext.c: Fix handling of NULL bytes inside

    15 +	  subjectAltName general names, CVE-2013-4073.

    16 +	* OpenSSL/crypto/x509.c: Fix memory leak in get_extension().

    17 +

    18  2011-09-02  Jean-Paul Calderone  <[email protected]>

    19  

    20  	* Release 0.13

    21 --- pyOpenSSL-0.13/OpenSSL/crypto/x509.c	2011-09-02 08:46:13.000000000 -0700

    22 +++ pyOpenSSL-0.13/OpenSSL/crypto/x509.c	2013-08-26 14:41:34.379545946 -0700

    23 @@ -756,6 +756,7 @@

    24  

    25      extobj = PyObject_New(crypto_X509ExtensionObj, &crypto_X509Extension_Type);

    26      extobj->x509_extension = X509_EXTENSION_dup(ext);

    27 +    extobj->dealloc = 1;

    28  

    29      return (PyObject*)extobj;

    30  }

    31 --- pyOpenSSL-0.13/OpenSSL/crypto/x509ext.c	2011-09-02 08:46:13.000000000 -0700

    32 +++ pyOpenSSL-0.13/OpenSSL/crypto/x509ext.c	2013-08-26 14:53:08.501972021 -0700

    33 @@ -236,6 +236,75 @@

    34      PyObject_Del(self);

    35  }

    36  

    37 +

    38 +/* Special handling of subjectAltName, see CVE-2013-4073 */

    39 +

    40 +int

    41 +crypto_X509Extension_str_san(crypto_X509ExtensionObj *self, BIO *bio)

    42 +{

    43 +    GENERAL_NAMES *names;

    44 +    const X509V3_EXT_METHOD *method = NULL;

    45 +    long i, length, num;

    46 +    const unsigned char *p;

    47 +

    48 +    method = X509V3_EXT_get(self->x509_extension);

    49 +    if (method == NULL) {

    50 +        return -1;

    51 +    }

    52 +

    53 +    p = self->x509_extension->value->data;

    54 +    length = self->x509_extension->value->length;

    55 +    if (method->it) {

    56 +        names = (GENERAL_NAMES*)(ASN1_item_d2i(NULL, &p, length,

    57 +                                               ASN1_ITEM_ptr(method->it)));

    58 +    }

    59 +    else {

    60 +        names = (GENERAL_NAMES*)(method->d2i(NULL, &p, length));

    61 +    }

    62 +    if (names == NULL) {

    63 +        return -1;

    64 +    }

    65 +

    66 +    num = sk_GENERAL_NAME_num(names);

    67 +    for (i = 0; i < num; i++) {

    68 +            GENERAL_NAME *name;

    69 +            ASN1_STRING *as;

    70 +            name = sk_GENERAL_NAME_value(names, i);

    71 +            switch (name->type) {

    72 +                case GEN_EMAIL:

    73 +                    BIO_puts(bio, "email:");

    74 +                    as = name->d.rfc822Name;

    75 +                    BIO_write(bio, ASN1_STRING_data(as),

    76 +                              ASN1_STRING_length(as));

    77 +                    break;

    78 +                case GEN_DNS:

    79 +                    BIO_puts(bio, "DNS:");

    80 +                    as = name->d.dNSName;

    81 +                    BIO_write(bio, ASN1_STRING_data(as),

    82 +                              ASN1_STRING_length(as));

    83 +                    break;

    84 +                case GEN_URI:

    85 +                    BIO_puts(bio, "URI:");

    86 +                    as = name->d.uniformResourceIdentifier;

    87 +                    BIO_write(bio, ASN1_STRING_data(as),

    88 +                              ASN1_STRING_length(as));

    89 +                    break;

    90 +                default:

    91 +                    /* use builtin print for GEN_OTHERNAME, GEN_X400,

    92 +                     * GEN_EDIPARTY, GEN_DIRNAME, GEN_IPADD and GEN_RID

    93 +                     */

    94 +                    GENERAL_NAME_print(bio, name);

    95 +            }

    96 +            /* trailing ', ' except for last element */

    97 +            if (i < (num - 1)) {

    98 +                BIO_puts(bio, ", ");

    99 +            }

   100 +    }

   101 +    sk_GENERAL_NAME_pop_free(names, GENERAL_NAME_free);

   102 +

   103 +    return 0;

   104 +}

   105 +

   106  /*

   107   * Print a nice text representation of the certificate request.

   108   */

   109 @@ -247,7 +316,14 @@

   110      PyObject *str;

   111      BIO *bio = BIO_new(BIO_s_mem());

   112  

   113 -    if (!X509V3_EXT_print(bio, self->x509_extension, 0, 0))

   114 +    if (OBJ_obj2nid(self->x509_extension->object) == NID_subject_alt_name) {

   115 +        if (crypto_X509Extension_str_san(self, bio) == -1) {

   116 +            BIO_free(bio);

   117 +            exception_from_error_queue(crypto_Error);

   118 +            return NULL;

   119 +        }

   120 +    }

   121 +    else if (!X509V3_EXT_print(bio, self->x509_extension, 0, 0))

   122      {

   123          BIO_free(bio);

   124          exception_from_error_queue(crypto_Error);

   125 --- pyOpenSSL-0.13/OpenSSL/test/test_crypto.py	2011-09-02 08:46:13.000000000 -0700

   126 +++ pyOpenSSL-0.13/OpenSSL/test/test_crypto.py	2013-08-26 14:57:06.933614387 -0700

   127 @@ -265,6 +265,37 @@

   128  -----END RSA PRIVATE KEY-----

   129  """)

   130  

   131 +# certificate with NULL bytes in subjectAltName and common name

   132 +

   133 +nullbyte_san_PEM = b("""-----BEGIN CERTIFICATE-----

   134 +MIIE2DCCA8CgAwIBAgIBADANBgkqhkiG9w0BAQUFADCBxTELMAkGA1UEBhMCVVMx

   135 +DzANBgNVBAgMBk9yZWdvbjESMBAGA1UEBwwJQmVhdmVydG9uMSMwIQYDVQQKDBpQ

   136 +eXRob24gU29mdHdhcmUgRm91bmRhdGlvbjEgMB4GA1UECwwXUHl0aG9uIENvcmUg

   137 +RGV2ZWxvcG1lbnQxJDAiBgNVBAMMG251bGwucHl0aG9uLm9yZwBleGFtcGxlLm9y

   138 +ZzEkMCIGCSqGSIb3DQEJARYVcHl0aG9uLWRldkBweXRob24ub3JnMB4XDTEzMDgw

   139 +NzEzMTE1MloXDTEzMDgwNzEzMTI1MlowgcUxCzAJBgNVBAYTAlVTMQ8wDQYDVQQI

   140 +DAZPcmVnb24xEjAQBgNVBAcMCUJlYXZlcnRvbjEjMCEGA1UECgwaUHl0aG9uIFNv

   141 +ZnR3YXJlIEZvdW5kYXRpb24xIDAeBgNVBAsMF1B5dGhvbiBDb3JlIERldmVsb3Bt

   142 +ZW50MSQwIgYDVQQDDBtudWxsLnB5dGhvbi5vcmcAZXhhbXBsZS5vcmcxJDAiBgkq

   143 +hkiG9w0BCQEWFXB5dGhvbi1kZXZAcHl0aG9uLm9yZzCCASIwDQYJKoZIhvcNAQEB

   144 +BQADggEPADCCAQoCggEBALXq7cn7Rn1vO3aA3TrzA5QLp6bb7B3f/yN0CJ2XFj+j

   145 +pHs+Gw6WWSUDpybiiKnPec33BFawq3kyblnBMjBU61ioy5HwQqVkJ8vUVjGIUq3P

   146 +vX/wBmQfzCe4o4uM89gpHyUL9UYGG8oCRa17dgqcv7u5rg0Wq2B1rgY+nHwx3JIv

   147 +KRrgSwyRkGzpN8WQ1yrXlxWjgI9de0mPVDDUlywcWze1q2kwaEPTM3hLAmD1PESA

   148 +oY/n8A/RXoeeRs9i/Pm/DGUS8ZPINXk/yOzsR/XvvkTVroIeLZqfmFpnZeF0cHzL

   149 +08LODkVJJ9zjLdT7SA4vnne4FEbAxDbKAq5qkYzaL4UCAwEAAaOB0DCBzTAMBgNV

   150 +HRMBAf8EAjAAMB0GA1UdDgQWBBSIWlXAUv9hzVKjNQ/qWpwkOCL3XDALBgNVHQ8E

   151 +BAMCBeAwgZAGA1UdEQSBiDCBhYIeYWx0bnVsbC5weXRob24ub3JnAGV4YW1wbGUu

   152 +Y29tgSBudWxsQHB5dGhvbi5vcmcAdXNlckBleGFtcGxlLm9yZ4YpaHR0cDovL251

   153 +bGwucHl0aG9uLm9yZwBodHRwOi8vZXhhbXBsZS5vcmeHBMAAAgGHECABDbgAAAAA

   154 +AAAAAAAAAAEwDQYJKoZIhvcNAQEFBQADggEBAKxPRe99SaghcI6IWT7UNkJw9aO9

   155 +i9eo0Fj2MUqxpKbdb9noRDy2CnHWf7EIYZ1gznXPdwzSN4YCjV5d+Q9xtBaowT0j

   156 +HPERs1ZuytCNNJTmhyqZ8q6uzMLoht4IqH/FBfpvgaeC5tBTnTT0rD5A/olXeimk

   157 +kX4LxlEx5RAvpGB2zZVRGr6LobD9rVK91xuHYNIxxxfEGE8tCCWjp0+3ksri9SXx

   158 +VHWBnbM9YaL32u3hxm8sYB/Yb8WSBavJCWJJqRStVRHM1koZlJmXNx2BX4vPo6iW

   159 +RFEIPQsFZRLrtnCAiEhyT8bC2s/Njlu6ly9gtJZWSV46Q3ZjBL4q9sHKqZQ=

   160 +-----END CERTIFICATE-----""")

   161 +

   162  

   163  class X509ExtTests(TestCase):

   164      """

   165 @@ -1382,6 +1413,36 @@

   166          self.assertRaises(TypeError, cert.get_extension, "hello")

   167  

   168  

   169 +    def test_nullbyte_san(self):

   170 +        """

   171 +        Test correct handling of CN and SAN with NULL bytes

   172 +

   173 +        see CVE-2013-4073

   174 +        """

   175 +        cert = load_certificate(FILETYPE_PEM, nullbyte_san_PEM)

   176 +        subject = cert.get_subject()

   177 +        self.assertEqual(subject.CN, 'null.python.org\x00example.org')

   178 +        issuer = cert.get_issuer()

   179 +        self.assertEqual(issuer.CN, 'null.python.org\x00example.org')

   180 +

   181 +        ext = cert.get_extension(0)

   182 +        self.assertEqual(ext.get_short_name(), b('basicConstraints'))

   183 +

   184 +        ext = cert.get_extension(1)

   185 +        self.assertEqual(ext.get_short_name(), b('subjectKeyIdentifier'))

   186 +

   187 +        ext = cert.get_extension(2)

   188 +        self.assertEqual(ext.get_short_name(), b('keyUsage'))

   189 +

   190 +        ext = cert.get_extension(3)

   191 +        self.assertEqual(ext.get_short_name(), b('subjectAltName'))

   192 +        self.assertEqual(str(ext), 

   193 +            'DNS:altnull.python.org\x00example.com, '

   194 +            'email:[email protected]\[email protected], '

   195 +            'URI:http://null.python.org\x00http://example.org, '

   196 +            'IP Address:192.0.2.1, IP Address:2001:DB8:0:0:0:0:0:1\n')

   197 +

   198 +

   199      def test_invalid_digest_algorithm(self):

   200          """

   201          L{X509.digest} raises L{ValueError} if called with an unrecognized hash