- 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).
This commit is contained in:
Barry Warsaw 2013-08-23 13:26:49 -04:00
parent f880e5d5ea
commit 82f8828317
5 changed files with 216 additions and 35 deletions

View File

@ -1,32 +1,31 @@
-----BEGIN RSA PRIVATE KEY-----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-----END RSA PRIVATE KEY-----
-----BEGIN PRIVATE KEY-----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-----END PRIVATE KEY-----
-----BEGIN CERTIFICATE-----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MIICVDCCAb2gAwIBAgIJANfHOBkZr8JOMA0GCSqGSIb3DQEBBQUAMF8xCzAJBgNV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-----END CERTIFICATE-----

90
Lib/test/nullbytecert.pem Normal file
View File

@ -0,0 +1,90 @@
Certificate:
Data:
Version: 3 (0x2)
Serial Number: 0 (0x0)
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
Validity
Not Before: Aug 7 13:11:52 2013 GMT
Not After : Aug 7 13:12:52 2013 GMT
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
Subject Public Key Info:
Public Key Algorithm: rsaEncryption
Public-Key: (2048 bit)
Modulus:
00:b5:ea:ed:c9:fb:46:7d:6f:3b:76:80:dd:3a:f3:
03:94:0b:a7:a6:db:ec:1d:df:ff:23:74:08:9d:97:
16:3f:a3:a4:7b:3e:1b:0e:96:59:25:03:a7:26:e2:
88:a9:cf:79:cd:f7:04:56:b0:ab:79:32:6e:59:c1:
32:30:54:eb:58:a8:cb:91:f0:42:a5:64:27:cb:d4:
56:31:88:52:ad:cf:bd:7f:f0:06:64:1f:cc:27:b8:
a3:8b:8c:f3:d8:29:1f:25:0b:f5:46:06:1b:ca:02:
45:ad:7b:76:0a:9c:bf:bb:b9:ae:0d:16:ab:60:75:
ae:06:3e:9c:7c:31:dc:92:2f:29:1a:e0:4b:0c:91:
90:6c:e9:37:c5:90:d7:2a:d7:97:15:a3:80:8f:5d:
7b:49:8f:54:30:d4:97:2c:1c:5b:37:b5:ab:69:30:
68:43:d3:33:78:4b:02:60:f5:3c:44:80:a1:8f:e7:
f0:0f:d1:5e:87:9e:46:cf:62:fc:f9:bf:0c:65:12:
f1:93:c8:35:79:3f:c8:ec:ec:47:f5:ef:be:44:d5:
ae:82:1e:2d:9a:9f:98:5a:67:65:e1:74:70:7c:cb:
d3:c2:ce:0e:45:49:27:dc:e3:2d:d4:fb:48:0e:2f:
9e:77:b8:14:46:c0:c4:36:ca:02:ae:6a:91:8c:da:
2f:85
Exponent: 65537 (0x10001)
X509v3 extensions:
X509v3 Basic Constraints: critical
CA:FALSE
X509v3 Subject Key Identifier:
88:5A:55:C0:52:FF:61:CD:52:A3:35:0F:EA:5A:9C:24:38:22:F7:5C
X509v3 Key Usage:
Digital Signature, Non Repudiation, Key Encipherment
X509v3 Subject Alternative Name:
*************************************************************
WARNING: The values for DNS, email and URI are WRONG. OpenSSL
doesn't print the text after a NULL byte.
*************************************************************
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
Signature Algorithm: sha1WithRSAEncryption
ac:4f:45:ef:7d:49:a8:21:70:8e:88:59:3e:d4:36:42:70:f5:
a3:bd:8b:d7:a8:d0:58:f6:31:4a:b1:a4:a6:dd:6f:d9:e8:44:
3c:b6:0a:71:d6:7f:b1:08:61:9d:60:ce:75:cf:77:0c:d2:37:
86:02:8d:5e:5d:f9:0f:71:b4:16:a8:c1:3d:23:1c:f1:11:b3:
56:6e:ca:d0:8d:34:94:e6:87:2a:99:f2:ae:ae:cc:c2:e8:86:
de:08:a8:7f:c5:05:fa:6f:81:a7:82:e6:d0:53:9d:34:f4:ac:
3e:40:fe:89:57:7a:29:a4:91:7e:0b:c6:51:31:e5:10:2f:a4:
60:76:cd:95:51:1a:be:8b:a1:b0:fd:ad:52:bd:d7:1b:87:60:
d2:31:c7:17:c4:18:4f:2d:08:25:a3:a7:4f:b7:92:ca:e2:f5:
25:f1:54:75:81:9d:b3:3d:61:a2:f7:da:ed:e1:c6:6f:2c:60:
1f:d8:6f:c5:92:05:ab:c9:09:62:49:a9:14:ad:55:11:cc:d6:
4a:19:94:99:97:37:1d:81:5f:8b:cf:a3:a8:96:44:51:08:3d:
0b:05:65:12:eb:b6:70:80:88:48:72:4f:c6:c2:da:cf:cd:8e:
5b:ba:97:2f:60:b4:96:56:49:5e:3a:43:76:63:04:be:2a:f6:
c1:ca:a9:94
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----

View File

@ -31,6 +31,7 @@ except ImportError:
HOST = test_support.HOST
CERTFILE = None
SVN_PYTHON_ORG_ROOT_CERT = None
NULLBYTECERT = None
def handle_error(prefix):
exc_format = ' '.join(traceback.format_exception(*sys.exc_info()))
@ -88,6 +89,27 @@ class BasicTests(unittest.TestCase):
if test_support.verbose:
sys.stdout.write("\n" + pprint.pformat(p) + "\n")
def test_parse_cert_CVE_2013_4073(self):
p = ssl._ssl._test_decode_cert(NULLBYTECERT)
if test_support.verbose:
sys.stdout.write("\n" + pprint.pformat(p) + "\n")
subject = ((('countryName', 'US'),),
(('stateOrProvinceName', 'Oregon'),),
(('localityName', 'Beaverton'),),
(('organizationName', 'Python Software Foundation'),),
(('organizationalUnitName', 'Python Core Development'),),
(('commonName', 'null.python.org\x00example.org'),),
(('emailAddress', 'python-dev@python.org'),))
self.assertEqual(p['subject'], subject)
self.assertEqual(p['issuer'], subject)
self.assertEqual(p['subjectAltName'],
(('DNS', 'altnull.python.org\x00example.com'),
('email', 'null@python.org\x00user@example.org'),
('URI', 'http://null.python.org\x00http://example.org'),
('IP Address', '192.0.2.1'),
('IP Address', '2001:DB8:0:0:0:0:0:1\n'))
)
def test_DER_to_PEM(self):
with open(SVN_PYTHON_ORG_ROOT_CERT, 'r') as f:
pem = f.read()
@ -1210,15 +1232,18 @@ def test_main(verbose=False):
if skip_expected:
raise test_support.TestSkipped("No SSL support")
global CERTFILE, SVN_PYTHON_ORG_ROOT_CERT
global CERTFILE, SVN_PYTHON_ORG_ROOT_CERT, NULLBYTECERT
CERTFILE = os.path.join(os.path.dirname(__file__) or os.curdir,
"keycert.pem")
SVN_PYTHON_ORG_ROOT_CERT = os.path.join(
os.path.dirname(__file__) or os.curdir,
"https_svn_python_org_root.pem")
NULLBYTECERT = os.path.join(os.path.dirname(__file__) or os.curdir,
"nullbytecert.pem")
if (not os.path.exists(CERTFILE) or
not os.path.exists(SVN_PYTHON_ORG_ROOT_CERT)):
not os.path.exists(SVN_PYTHON_ORG_ROOT_CERT) or
not os.path.exists(NULLBYTECERT)):
raise test_support.TestFailed("Can't read certificate files!")
tests = [BasicTests]

View File

@ -16,6 +16,15 @@ Library
- Issue #16248: Disable code execution from the user's home directory by
tkinter when the -E flag is passed to Python. Patch by Zachary Ware.
Extension Modules
-----------------
- 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).
What's New in Python 2.6.8?
===========================

View File

@ -302,8 +302,10 @@ newPySSLObject(PySocketSockObject *Sock, char *key_file, char *cert_file,
self->ctx = SSL_CTX_new(TLSv1_method()); /* Set up context */
else if (proto_version == PY_SSL_VERSION_SSL3)
self->ctx = SSL_CTX_new(SSLv3_method()); /* Set up context */
#ifndef OPENSSL_NO_SSL2
else if (proto_version == PY_SSL_VERSION_SSL2)
self->ctx = SSL_CTX_new(SSLv2_method()); /* Set up context */
#endif
else if (proto_version == PY_SSL_VERSION_SSL23)
self->ctx = SSL_CTX_new(SSLv23_method()); /* Set up context */
PySSL_END_ALLOW_THREADS
@ -718,8 +720,13 @@ _get_peer_alt_names (X509 *certificate) {
/* get a rendering of each name in the set of names */
int gntype;
ASN1_STRING *as = NULL;
name = sk_GENERAL_NAME_value(names, j);
if (name->type == GEN_DIRNAME) {
gntype = name-> type;
switch (gntype) {
case GEN_DIRNAME:
/* we special-case DirName as a tuple of tuples of attributes */
@ -741,11 +748,61 @@ _get_peer_alt_names (X509 *certificate) {
goto fail;
}
PyTuple_SET_ITEM(t, 1, v);
break;
} else {
case GEN_EMAIL:
case GEN_DNS:
case GEN_URI:
/* GENERAL_NAME_print() doesn't handle NUL bytes in ASN1_string
correctly. */
t = PyTuple_New(2);
if (t == NULL)
goto fail;
switch (gntype) {
case GEN_EMAIL:
v = PyUnicode_FromString("email");
as = name->d.rfc822Name;
break;
case GEN_DNS:
v = PyUnicode_FromString("DNS");
as = name->d.dNSName;
break;
case GEN_URI:
v = PyUnicode_FromString("URI");
as = name->d.uniformResourceIdentifier;
break;
}
if (v == NULL) {
Py_DECREF(t);
goto fail;
}
PyTuple_SET_ITEM(t, 0, v);
v = PyString_FromStringAndSize((char *)ASN1_STRING_data(as),
ASN1_STRING_length(as));
if (v == NULL) {
Py_DECREF(t);
goto fail;
}
PyTuple_SET_ITEM(t, 1, v);
break;
default:
/* for everything else, we use the OpenSSL print form */
switch (gntype) {
/* check for new general name type */
case GEN_OTHERNAME:
case GEN_X400:
case GEN_EDIPARTY:
case GEN_IPADD:
case GEN_RID:
break;
default:
if (PyErr_Warn(PyExc_RuntimeWarning,
"Unknown general name type") == -1) {
goto fail;
}
break;
}
(void) BIO_reset(biobuf);
GENERAL_NAME_print(biobuf, name);
len = BIO_gets(biobuf, buf, sizeof(buf)-1);
@ -771,6 +828,7 @@ _get_peer_alt_names (X509 *certificate) {
goto fail;
}
PyTuple_SET_ITEM(t, 1, v);
break;
}
/* and add that rendering to the list */