Issue #27691: Fix ssl module's parsing of GEN_RID subject alternative name fields in X.509 certs.

Lib/test/allsans.pem

+-----BEGIN PRIVATE KEY-----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+-----END PRIVATE KEY-----
+-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----

Lib/test/make_ssl_certs.py

@@ -20,7 +20,28 @@ req_template = """
     CN                     = {hostname}
 
     [req_x509_extensions]
-    subjectAltName         = DNS:{hostname}
+    subjectAltName         = @san
+
+    [san]
+    DNS.1 = {hostname}
+    {extra_san}
+
+    [dir_sect]
+    C                      = XY
+    L                      = Castle Anthrax
+    O                      = Python Software Foundation
+    CN                     = dirname example
+
+    [princ_name]
+    realm = EXP:0, GeneralString:KERBEROS.REALM
+    principal_name = EXP:1, SEQUENCE:principal_seq
+
+    [principal_seq]
+    name_type = EXP:0, INTEGER:1
+    name_string = EXP:1, SEQUENCE:principals
+
+    [principals]
+    princ1 = GeneralString:username
 
     [ ca ]
     default_ca      = CA_default
@@ -67,7 +88,7 @@ req_template = """
 
 here = os.path.abspath(os.path.dirname(__file__))
 
-def make_cert_key(hostname, sign=False):
+def make_cert_key(hostname, sign=False, extra_san=''):
     print("creating cert for " + hostname)
     tempnames = []
     for i in range(3):
@@ -75,8 +96,9 @@ def make_cert_key(hostname, sign=False):
             tempnames.append(f.name)
     req_file, cert_file, key_file = tempnames
     try:
+        req = req_template.format(hostname=hostname, extra_san=extra_san)
         with open(req_file, 'w') as f:
-            f.write(req_template.format(hostname=hostname))
+            f.write(req)
         args = ['req', '-new', '-days', '3650', '-nodes',
                 '-newkey', 'rsa:1024', '-keyout', key_file,
                 '-config', req_file]
@@ -120,7 +142,7 @@ def make_ca():
         f.write('unique_subject = no')
 
     with tempfile.NamedTemporaryFile("w") as t:
-        t.write(req_template.format(hostname='our-ca-server'))
+        t.write(req_template.format(hostname='our-ca-server', extra_san=''))
         t.flush()
         with tempfile.NamedTemporaryFile() as f:
             args = ['req', '-new', '-days', '3650', '-extensions', 'v3_ca', '-nodes',
@@ -171,6 +193,25 @@ if __name__ == '__main__':
         f.write(key)
         f.write(cert)
 
+    extra_san = [
+        'otherName.1 = 1.2.3.4;UTF8:some other identifier',
+        'otherName.2 = 1.3.6.1.5.2.2;SEQUENCE:princ_name',
+        'email.1 = user@example.org',
+        'DNS.2 = www.example.org',
+        # GEN_X400
+        'dirName.1 = dir_sect',
+        # GEN_EDIPARTY
+        'URI.1 = https://www.python.org/',
+        'IP.1 = 127.0.0.1',
+        'IP.2 = ::1',
+        'RID.1 = 1.2.3.4.5',
+    ]
+
+    cert, key = make_cert_key('allsans', extra_san='\n'.join(extra_san))
+    with open('allsans.pem', 'w') as f:
+        f.write(key)
+        f.write(cert)
+
     unmake_ca()
     print("\n\nPlease change the values in test_ssl.py, test_parse_cert function related to notAfter,notBefore and serialNumber")
     check_call(['openssl','x509','-in','keycert.pem','-dates','-serial','-noout'])

Lib/test/test_ssl.py

@@ -57,6 +57,8 @@ CRLFILE = data_file("revocation.crl")
 SIGNED_CERTFILE = data_file("keycert3.pem")
 SIGNED_CERTFILE2 = data_file("keycert4.pem")
 SIGNING_CA = data_file("pycacert.pem")
+# cert with all kinds of subject alt names
+ALLSANFILE = data_file("allsans.pem")
 
 REMOTE_HOST = "self-signed.pythontest.net"
 REMOTE_ROOT_CERT = data_file("selfsigned_pythontestdotnet.pem")
@@ -279,6 +281,27 @@ class BasicSocketTests(unittest.TestCase):
 
         self.assertEqual(p['subjectAltName'], san)
 
+    def test_parse_all_sans(self):
+        p = ssl._ssl._test_decode_cert(ALLSANFILE)
+        self.assertEqual(p['subjectAltName'],
+            (
+                ('DNS', 'allsans'),
+                ('othername', '<unsupported>'),
+                ('othername', '<unsupported>'),
+                ('email', 'user@example.org'),
+                ('DNS', 'www.example.org'),
+                ('DirName',
+                    ((('countryName', 'XY'),),
+                    (('localityName', 'Castle Anthrax'),),
+                    (('organizationName', 'Python Software Foundation'),),
+                    (('commonName', 'dirname example'),))),
+                ('URI', 'https://www.python.org/'),
+                ('IP Address', '127.0.0.1'),
+                ('IP Address', '0:0:0:0:0:0:0:1\n'),
+                ('Registered ID', '1.2.3.4.5')
+            )
+        )
+
     def test_DER_to_PEM(self):
         with open(CAFILE_CACERT, 'r') as f:
             pem = f.read()

Misc/NEWS

@@ -60,6 +60,9 @@ Core and Builtins
 Library
 -------
 
+- Issue #27691: Fix ssl module's parsing of GEN_RID subject alternative name
+  fields in X.509 certs.
+
 - Issue #27850: Remove 3DES from ssl module's default cipher list to counter
   measure sweet32 attack (CVE-2016-2183).
 

Modules/_ssl.c

@@ -1007,6 +1007,35 @@ _get_peer_alt_names (X509 *certificate) {
                 PyTuple_SET_ITEM(t, 1, v);
                 break;
 
+            case GEN_RID:
+                t = PyTuple_New(2);
+                if (t == NULL)
+                    goto fail;
+
+                v = PyUnicode_FromString("Registered ID");
+                if (v == NULL) {
+                    Py_DECREF(t);
+                    goto fail;
+                }
+                PyTuple_SET_ITEM(t, 0, v);
+
+                len = i2t_ASN1_OBJECT(buf, sizeof(buf)-1, name->d.rid);
+                if (len < 0) {
+                    Py_DECREF(t);
+                    _setSSLError(NULL, 0, __FILE__, __LINE__);
+                    goto fail;
+                } else if (len >= (int)sizeof(buf)) {
+                    v = PyUnicode_FromString("<INVALID>");
+                } else {
+                    v = PyUnicode_FromStringAndSize(buf, len);
+                }
+                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) {
@@ -1033,8 +1062,12 @@ _get_peer_alt_names (X509 *certificate) {
                     goto fail;
                 }
                 vptr = strchr(buf, ':');
-                if (vptr == NULL)
+                if (vptr == NULL) {
+                    PyErr_Format(PyExc_ValueError,
+                                 "Invalid value %.200s",
+                                 buf);
                     goto fail;
+                }
                 t = PyTuple_New(2);
                 if (t == NULL)
                     goto fail;