cpython: 386b0f478117 (original) (raw)

Mercurial > cpython

changeset 92658:386b0f478117 3.2

Issue #18709: Fix CVE-2013-4238. The SSL module now handles NULL bytes inside subjectAltName correctly. Formerly the module has used OpenSSL's GENERAL_NAME_print() function to get the string represention of ASN.1 strings for ``rfc822Name`` (email), ``dNSName`` (DNS) and ``uniformResourceIdentifier`` (URI). [#18709]

Georg Brandl georg@python.org
date	Tue, 30 Sep 2014 14:04:51 +0200
parents	634f3fe8cbde
children	deee87d61436
files	Lib/test/nullbytecert.pem Lib/test/test_ssl.py Misc/NEWS Modules/_ssl.c
diffstat	4 files changed, 186 insertions(+), 7 deletions(-)[+] [-] Lib/test/nullbytecert.pem 90 Lib/test/test_ssl.py 29 Misc/NEWS 6 Modules/_ssl.c 68

line wrap: on

line diff

new file mode 100644 --- /dev/null +++ b/Lib/test/nullbytecert.pem @@ -0,0 +1,90 @@ +Certificate:

Data:
```
   Version: 3 (0x2)[](#l1.7)
```
```
   Serial Number: 0 (0x0)[](#l1.8)
```
Signature Algorithm: sha1WithRSAEncryption

   Issuer: C=US, ST=Oregon, L=Beaverton, O=Python Software Foundation, OU=Python Core Development, CN=null.python.org\x00example.org/emailAddress=python-dev@python.org[](#l1.10)

```
   Validity[](#l1.11)
```

       Not Before: Aug  7 13:11:52 2013 GMT[](#l1.12)

       Not After : Aug  7 13:12:52 2013 GMT[](#l1.13)

   Subject: C=US, ST=Oregon, L=Beaverton, O=Python Software Foundation, OU=Python Core Development, CN=null.python.org\x00example.org/emailAddress=python-dev@python.org[](#l1.14)

```
   Subject Public Key Info:[](#l1.15)
```

       Public Key Algorithm: rsaEncryption[](#l1.16)

           Public-Key: (2048 bit)[](#l1.17)

```
           Modulus:[](#l1.18)
```

               00:b5:ea:ed:c9:fb:46:7d:6f:3b:76:80:dd:3a:f3:[](#l1.19)

               03:94:0b:a7:a6:db:ec:1d:df:ff:23:74:08:9d:97:[](#l1.20)

               16:3f:a3:a4:7b:3e:1b:0e:96:59:25:03:a7:26:e2:[](#l1.21)

               88:a9:cf:79:cd:f7:04:56:b0🆎79:32:6e:59:c1:[](#l1.22)

               32:30:54:eb:58:a8:cb:91:f0:42:a5:64:27:cb:d4:[](#l1.23)

               56:31:88:52:ad:cf:bd:7f:f0:06:64:1f:cc:27:b8:[](#l1.24)

               a3:8b:8c:f3:d8:29:1f:25:0b:f5:46:06:1b:ca:02:[](#l1.25)

               45:ad:7b:76:0a:9c:bf:bb:b9:ae:0d:16:ab:60:75:[](#l1.26)

               ae:06:3e:9c:7c:31:dc:92:2f:29:1a:e0:4b:0c:91:[](#l1.27)

               90:6c:e9:37:c5:90:d7:2a:d7:97:15:a3:80:8f:5d:[](#l1.28)

               7b:49:8f:54:30:d4:97:2c:1c:5b:37:b5:ab:69:30:[](#l1.29)

               68:43:d3:33:78:4b:02:60:f5:3c:44:80:a1:8f:e7:[](#l1.30)

               f0:0f:d1:5e:87:9e:46:cf:62:fc:f9:bf:0c:65:12:[](#l1.31)

               f1:93:c8:35:79:3f:c8:ec:ec:47:f5:ef:be:44:d5:[](#l1.32)

               ae:82:1e:2d:9a:9f:98:5a:67:65:e1:74:70:7c:cb:[](#l1.33)

               d3:c2:ce:0e:45:49:27:dc:e3:2d:d4:fb:48:0e:2f:[](#l1.34)

               9e:77:b8:14:46:c0:c4:36:ca:02:ae:6a:91:8c:da:[](#l1.35)

```
               2f:85[](#l1.36)
```

           Exponent: 65537 (0x10001)[](#l1.37)

```
   X509v3 extensions:[](#l1.38)
```

       X509v3 Basic Constraints: critical[](#l1.39)

```
           CA:FALSE[](#l1.40)
```

       X509v3 Subject Key Identifier:[](#l1.41)

           88:5A:55:C0:52:FF:61:CD:52:A3:35:0F:EA:5A:9C:24:38:22:F7:5C[](#l1.42)

```
       X509v3 Key Usage:[](#l1.43)
```

           Digital Signature, Non Repudiation, Key Encipherment[](#l1.44)

       X509v3 Subject Alternative Name:[](#l1.45)

           *************************************************************[](#l1.46)

           WARNING: The values for DNS, email and URI are WRONG. OpenSSL[](#l1.47)

                    doesn't print the text after a NULL byte.[](#l1.48)

           *************************************************************[](#l1.49)

           DNS:altnull.python.org, email:null@python.org, URI:http://null.python.org, IP Address:192.0.2.1, IP Address:2001:DB8:0:0:0:0:0:1[](#l1.50)

Signature Algorithm: sha1WithRSAEncryption

    ac:4f:45:ef:7d:49:a8:21:70:8e:88:59:3e:d4:36:42:70:f5:[](#l1.52)

    a3:bd:8b:d7:a8:d0:58:f6:31:4a:b1:a4:a6:dd:6f:d9:e8:44:[](#l1.53)

    3c:b6:0a:71:d6:7f:b1:08:61:9d:60:ce:75:cf:77:0c:d2:37:[](#l1.54)

    86:02:8d:5e:5d:f9:0f:71:b4:16:a8:c1:3d:23:1c:f1:11:b3:[](#l1.55)

    56:6e:ca:d0:8d:34:94:e6:87:2a:99:f2:ae:ae:cc:c2:e8:86:[](#l1.56)

    de:08:a8:7f:c5:05:fa:6f:81:a7:82:e6:d0:53:9d:34:f4:ac:[](#l1.57)

    3e:40:fe:89:57:7a:29:a4:91:7e:0b:c6:51:31:e5:10:2f:a4:[](#l1.58)

    60:76:cd:95:51:1a:be:8b:a1:b0:fd:ad:52:bd:d7:1b:87:60:[](#l1.59)

    d2:31:c7:17:c4🔞4f:2d:08:25:a3:a7:4f:b7:92:ca:e2:f5:[](#l1.60)

    25:f1:54:75:81:9d:b3:3d:61:a2:f7:da:ed:e1:c6:6f:2c:60:[](#l1.61)

    1f:d8:6f:c5:92:05:ab:c9:09:62:49:a9:14:ad:55:11:cc:d6:[](#l1.62)

    4a:19:94:99:97:37:1d:81:5f:8b:cf:a3:a8:96:44:51:08:3d:[](#l1.63)

    0b:05:65:12:eb:b6:70:80:88:48:72:4f:c6:c2:da:cf:cd:8e:[](#l1.64)

    5b:ba:97:2f:60:b4:96:56:49:5e:3a:43:76:63:04:be:2a:f6:[](#l1.65)

```
    c1:ca:a9:94[](#l1.66)
```

+-----BEGIN CERTIFICATE----- +MIIE2DCCA8CgAwIBAgIBADANBgkqhkiG9w0BAQUFADCBxTELMAkGA1UEBhMCVVMx +DzANBgNVBAgMBk9yZWdvbjESMBAGA1UEBwwJQmVhdmVydG9uMSMwIQYDVQQKDBpQ +eXRob24gU29mdHdhcmUgRm91bmRhdGlvbjEgMB4GA1UECwwXUHl0aG9uIENvcmUg +RGV2ZWxvcG1lbnQxJDAiBgNVBAMMG251bGwucHl0aG9uLm9yZwBleGFtcGxlLm9y +ZzEkMCIGCSqGSIb3DQEJARYVcHl0aG9uLWRldkBweXRob24ub3JnMB4XDTEzMDgw +NzEzMTE1MloXDTEzMDgwNzEzMTI1MlowgcUxCzAJBgNVBAYTAlVTMQ8wDQYDVQQI +DAZPcmVnb24xEjAQBgNVBAcMCUJlYXZlcnRvbjEjMCEGA1UECgwaUHl0aG9uIFNv +ZnR3YXJlIEZvdW5kYXRpb24xIDAeBgNVBAsMF1B5dGhvbiBDb3JlIERldmVsb3Bt +ZW50MSQwIgYDVQQDDBtudWxsLnB5dGhvbi5vcmcAZXhhbXBsZS5vcmcxJDAiBgkq +hkiG9w0BCQEWFXB5dGhvbi1kZXZAcHl0aG9uLm9yZzCCASIwDQYJKoZIhvcNAQEB +BQADggEPADCCAQoCggEBALXq7cn7Rn1vO3aA3TrzA5QLp6bb7B3f/yN0CJ2XFj+j +pHs+Gw6WWSUDpybiiKnPec33BFawq3kyblnBMjBU61ioy5HwQqVkJ8vUVjGIUq3P +vX/wBmQfzCe4o4uM89gpHyUL9UYGG8oCRa17dgqcv7u5rg0Wq2B1rgY+nHwx3JIv +KRrgSwyRkGzpN8WQ1yrXlxWjgI9de0mPVDDUlywcWze1q2kwaEPTM3hLAmD1PESA +oY/n8A/RXoeeRs9i/Pm/DGUS8ZPINXk/yOzsR/XvvkTVroIeLZqfmFpnZeF0cHzL +08LODkVJJ9zjLdT7SA4vnne4FEbAxDbKAq5qkYzaL4UCAwEAAaOB0DCBzTAMBgNV +HRMBAf8EAjAAMB0GA1UdDgQWBBSIWlXAUv9hzVKjNQ/qWpwkOCL3XDALBgNVHQ8E +BAMCBeAwgZAGA1UdEQSBiDCBhYIeYWx0bnVsbC5weXRob24ub3JnAGV4YW1wbGUu +Y29tgSBudWxsQHB5dGhvbi5vcmcAdXNlckBleGFtcGxlLm9yZ4YpaHR0cDovL251 +bGwucHl0aG9uLm9yZwBodHRwOi8vZXhhbXBsZS5vcmeHBMAAAgGHECABDbgAAAAA +AAAAAAAAAAEwDQYJKoZIhvcNAQEFBQADggEBAKxPRe99SaghcI6IWT7UNkJw9aO9 +i9eo0Fj2MUqxpKbdb9noRDy2CnHWf7EIYZ1gznXPdwzSN4YCjV5d+Q9xtBaowT0j +HPERs1ZuytCNNJTmhyqZ8q6uzMLoht4IqH/FBfpvgaeC5tBTnTT0rD5A/olXeimk +kX4LxlEx5RAvpGB2zZVRGr6LobD9rVK91xuHYNIxxxfEGE8tCCWjp0+3ksri9SXx +VHWBnbM9YaL32u3hxm8sYB/Yb8WSBavJCWJJqRStVRHM1koZlJmXNx2BX4vPo6iW +RFEIPQsFZRLrtnCAiEhyT8bC2s/Njlu6ly9gtJZWSV46Q3ZjBL4q9sHKqZQ= +-----END CERTIFICATE-----

--- a/Lib/test/test_ssl.py +++ b/Lib/test/test_ssl.py @@ -52,6 +52,7 @@ BADCERT = data_file("badcert.pem") WRONGCERT = data_file("XXXnonexisting.pem") BADKEY = data_file("badkey.pem") NOKIACERT = data_file("nokia.pem") +NULLBYTECERT = data_file("nullbytecert.pem") def handle_error(prefix): @@ -140,6 +141,27 @@ class BasicSocketTests(unittest.TestCase ('DNS', 'projects.forum.nokia.com')) )

def test_parse_cert_CVE_2013_4073(self):

   p = ssl._ssl._test_decode_cert(NULLBYTECERT)[](#l2.16)

```
   if support.verbose:[](#l2.17)
```

       sys.stdout.write("\n" + pprint.pformat(p) + "\n")[](#l2.18)

   subject = ((('countryName', 'US'),),[](#l2.19)

              (('stateOrProvinceName', 'Oregon'),),[](#l2.20)

              (('localityName', 'Beaverton'),),[](#l2.21)

              (('organizationName', 'Python Software Foundation'),),[](#l2.22)

              (('organizationalUnitName', 'Python Core Development'),),[](#l2.23)

              (('commonName', 'null.python.org\x00example.org'),),[](#l2.24)

              (('emailAddress', 'python-dev@python.org'),))[](#l2.25)

   self.assertEqual(p['subject'], subject)[](#l2.26)

   self.assertEqual(p['issuer'], subject)[](#l2.27)

   self.assertEqual(p['subjectAltName'],[](#l2.28)

                    (('DNS', 'altnull.python.org\x00example.com'),[](#l2.29)

                    ('email', 'null@python.org\x00user@example.org'),[](#l2.30)

                    ('URI', 'http://null.python.org\x00http://example.org'),[](#l2.31)

                    ('IP Address', '192.0.2.1'),[](#l2.32)

                    ('IP Address', '2001:DB8:0:0:0:0:0:1\n'))[](#l2.33)

```
                   )[](#l2.34)
```

+ def test_DER_to_PEM(self): with open(SVN_PYTHON_ORG_ROOT_CERT, 'r') as f: pem = f.read() @@ -271,6 +293,13 @@ class BasicSocketTests(unittest.TestCase fail(cert, 'foo.a.com') fail(cert, 'bar.foo.com')

   # NULL bytes are bad, CVE-2013-4073[](#l2.43)

   cert = {'subject': ((('commonName',[](#l2.44)

                         'null.python.org\x00example.org'),),)}[](#l2.45)

   ok(cert, 'null.python.org\x00example.org') # or raise an error?[](#l2.46)

```
   fail(cert, 'example.org')[](#l2.47)
```

   fail(cert, 'null.python.org')[](#l2.48)

+ # Slightly fake real-world example cert = {'notAfter': 'Jun 26 21:41:46 2011 GMT', 'subject': ((('commonName', 'linuxfrz.org'),),),

--- a/Misc/NEWS +++ b/Misc/NEWS @@ -10,6 +10,12 @@ What's New in Python 3.2.6? Library ------- +- Issue #18709: Fix CVE-2013-4238. The SSL module now handles NULL bytes

inside subjectAltName correctly. Formerly the module has used OpenSSL's
GENERAL_NAME_print() function to get the string represention of ASN.1
strings for rfc822Name (email), dNSName (DNS) and
uniformResourceIdentifier (URI). +

Issue #21766: Prevent a security hole in CGIHTTPServer by URL unquoting paths before checking for a CGI script at that path.

--- a/Modules/_ssl.c +++ b/Modules/_ssl.c @@ -561,7 +561,7 @@ static PyObject * int i, j; PyObject *peer_alt_names = Py_None;

PyObject *v, *t;

PyObject *v = NULL, *t; X509_EXTENSION *ext = NULL; GENERAL_NAMES *names = NULL; GENERAL_NAME *name; @@ -616,12 +616,14 @@ static PyObject * ext->value->length));

for(j = 0; j < sk_GENERAL_NAME_num(names); j++) { - /* get a rendering of each name in the set of names */

```
       int gntype;[](#l4.18)
```

       ASN1_STRING *as = NULL;[](#l4.19)

name = sk_GENERAL_NAME_value(names, j);

       if (name->type == GEN_DIRNAME) {[](#l4.22)

```
       gntype = name-> type;[](#l4.24)
```
```
       switch (gntype) {[](#l4.25)
```

       case GEN_DIRNAME:[](#l4.26)
           /* we special-case DirName as a tuple of[](#l4.27)
              tuples of attributes */[](#l4.28)

@@ -643,11 +645,62 @@ static PyObject * goto fail; } PyTuple_SET_ITEM(t, 1, v); -

```
       } else {[](#l4.35)
```

```
           break;[](#l4.36)
```

```
       case GEN_EMAIL:[](#l4.38)
```
```
       case GEN_DNS:[](#l4.39)
```
```
       case GEN_URI:[](#l4.40)
```

           /* GENERAL_NAME_print() doesn't handle NUL bytes in ASN1_string[](#l4.41)

```
              correctly. */[](#l4.42)
```

           t = PyTuple_New(2);[](#l4.43)

```
           if (t == NULL)[](#l4.44)
```
```
               goto fail;[](#l4.45)
```
```
           switch (gntype) {[](#l4.46)
```
```
           case GEN_EMAIL:[](#l4.47)
```

               v = PyUnicode_FromString("email");[](#l4.48)

               as = name->d.rfc822Name;[](#l4.49)

```
               break;[](#l4.50)
```
```
           case GEN_DNS:[](#l4.51)
```

               v = PyUnicode_FromString("DNS");[](#l4.52)

               as = name->d.dNSName;[](#l4.53)

```
               break;[](#l4.54)
```
```
           case GEN_URI:[](#l4.55)
```

               v = PyUnicode_FromString("URI");[](#l4.56)

               as = name->d.uniformResourceIdentifier;[](#l4.57)

```
               break;[](#l4.58)
```
```
           }[](#l4.59)
```
```
           if (v == NULL) {[](#l4.60)
```
```
               Py_DECREF(t);[](#l4.61)
```
```
               goto fail;[](#l4.62)
```
```
           }[](#l4.63)
```

           PyTuple_SET_ITEM(t, 0, v);[](#l4.64)

           v = PyUnicode_FromStringAndSize((char *)ASN1_STRING_data(as),[](#l4.65)

                                           ASN1_STRING_length(as));[](#l4.66)

```
           if (v == NULL) {[](#l4.67)
```
```
               Py_DECREF(t);[](#l4.68)
```
```
               goto fail;[](#l4.69)
```
```
           }[](#l4.70)
```

           PyTuple_SET_ITEM(t, 1, v);[](#l4.71)

```
           break;[](#l4.72)
```

       default:[](#l4.74)
           /* for everything else, we use the OpenSSL print form */[](#l4.75)

```
           switch (gntype) {[](#l4.77)
```

               /* check for new general name type */[](#l4.78)

               case GEN_OTHERNAME:[](#l4.79)

```
               case GEN_X400:[](#l4.80)
```

               case GEN_EDIPARTY:[](#l4.81)

               case GEN_IPADD:[](#l4.82)

```
               case GEN_RID:[](#l4.83)
```
```
                   break;[](#l4.84)
```
```
               default:[](#l4.85)
```

                   if (PyErr_WarnFormat(PyExc_RuntimeWarning, 1,[](#l4.86)

                                        "Unknown general name type %d",[](#l4.87)

                                        gntype) == -1) {[](#l4.88)

                       goto fail;[](#l4.89)

```
                   }[](#l4.90)
```
```
                   break;[](#l4.91)
```

           }[](#l4.92)
           (void) BIO_reset(biobuf);[](#l4.93)
           GENERAL_NAME_print(biobuf, name);[](#l4.94)
           len = BIO_gets(biobuf, buf, sizeof(buf)-1);[](#l4.95)

@@ -674,6 +727,7 @@ static PyObject * goto fail; } PyTuple_SET_ITEM(t, 1, v);

           break;[](#l4.100)
       }[](#l4.101)

/* and add that rendering to the list */