1 |
From 8a696458dac335071d98f39dfd1380192fbe7733 Mon Sep 17 00:00:00 2001 |
2 |
From: Alexander Bokovoy <ab@samba.org> |
3 |
Date: Fri, 10 Mar 2017 16:20:06 +0200 |
4 |
Subject: [PATCH] lib/crypto: implement samba.crypto Python module for RC4 |
5 |
MIME-Version: 1.0 |
6 |
Content-Type: text/plain; charset=UTF-8 |
7 |
Content-Transfer-Encoding: 8bit |
8 |
|
9 |
Implement a small Python module that exposes arcfour_crypt_blob() |
10 |
function widely used in Samba C code. |
11 |
|
12 |
When Samba Python bindings are used to call LSA CreateTrustedDomainEx2, |
13 |
there is a need to encrypt trusted credentials with RC4 cipher. |
14 |
|
15 |
Current Samba Python code relies on Python runtime to provide RC4 |
16 |
cipher. However, in FIPS 140-2 mode system crypto libraries do not |
17 |
provide access RC4 cipher at all. According to Microsoft dochelp team, |
18 |
Windows is treating AuthenticationInformation blob encryption as 'plain |
19 |
text' in terms of FIPS 140-2, thus doing application-level encryption. |
20 |
|
21 |
Replace samba.arcfour_encrypt() implementation with a call to |
22 |
samba.crypto.arcfour_crypt_blob(). |
23 |
|
24 |
Signed-off-by: Alexander Bokovoy <ab@samba.org> |
25 |
Reviewed-by: Simo Sorce <idra@samba.org> |
26 |
Reviewed-by: Guenther Deschner <gd@samba.org> |
27 |
|
28 |
Autobuild-User(master): Günther Deschner <gd@samba.org> |
29 |
Autobuild-Date(master): Wed Mar 15 01:30:24 CET 2017 on sn-devel-144 |
30 |
|
31 |
(cherry picked from commit bbeef554f2c15e739f6095fcb57d9ef6646b411c) |
32 |
--- |
33 |
lib/crypto/py_crypto.c | 90 ++++++++++++++++++++++++++++++++++++++++++++++++ |
34 |
lib/crypto/wscript_build | 7 ++++ |
35 |
python/samba/__init__.py | 16 ++------- |
36 |
3 files changed, 99 insertions(+), 14 deletions(-) |
37 |
create mode 100644 lib/crypto/py_crypto.c |
38 |
|
39 |
diff --git a/lib/crypto/py_crypto.c b/lib/crypto/py_crypto.c |
40 |
new file mode 100644 |
41 |
index 0000000..bf7f9f4 |
42 |
--- /dev/null |
43 |
+++ b/lib/crypto/py_crypto.c |
44 |
@@ -0,0 +1,90 @@ |
45 |
+/* |
46 |
+ Unix SMB/CIFS implementation. |
47 |
+ Samba crypto functions |
48 |
+ |
49 |
+ Copyright (C) Alexander Bokovoy <ab@samba.org> 2017 |
50 |
+ |
51 |
+ This program is free software; you can redistribute it and/or modify |
52 |
+ it under the terms of the GNU General Public License as published by |
53 |
+ the Free Software Foundation; either version 3 of the License, or |
54 |
+ (at your option) any later version. |
55 |
+ |
56 |
+ This program is distributed in the hope that it will be useful, |
57 |
+ but WITHOUT ANY WARRANTY; without even the implied warranty of |
58 |
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
59 |
+ GNU General Public License for more details. |
60 |
+ |
61 |
+ You should have received a copy of the GNU General Public License |
62 |
+ along with this program. If not, see <http://www.gnu.org/licenses/>. |
63 |
+*/ |
64 |
+ |
65 |
+#include <Python.h> |
66 |
+#include "includes.h" |
67 |
+#include "python/py3compat.h" |
68 |
+#include "lib/crypto/arcfour.h" |
69 |
+ |
70 |
+static PyObject *py_crypto_arcfour_crypt_blob(PyObject *module, PyObject *args, PyObject *kwargs) |
71 |
+{ |
72 |
+ DATA_BLOB data, key; |
73 |
+ PyObject *py_data, *py_key, *result; |
74 |
+ TALLOC_CTX *ctx; |
75 |
+ |
76 |
+ if (!PyArg_ParseTuple(args, "OO", &py_data, &py_key)) |
77 |
+ return NULL; |
78 |
+ |
79 |
+ if (!PyBytes_Check(py_data)) { |
80 |
+ PyErr_Format(PyExc_TypeError, "bytes expected"); |
81 |
+ return NULL; |
82 |
+ } |
83 |
+ |
84 |
+ if (!PyBytes_Check(py_key)) { |
85 |
+ PyErr_Format(PyExc_TypeError, "bytes expected"); |
86 |
+ return NULL; |
87 |
+ } |
88 |
+ |
89 |
+ ctx = talloc_new(NULL); |
90 |
+ |
91 |
+ data.length = PyBytes_Size(py_data); |
92 |
+ data.data = talloc_memdup(ctx, PyBytes_AsString(py_data), data.length); |
93 |
+ if (!data.data) { |
94 |
+ talloc_free(ctx); |
95 |
+ return PyErr_NoMemory(); |
96 |
+ } |
97 |
+ |
98 |
+ key.data = (uint8_t *)PyBytes_AsString(py_key); |
99 |
+ key.length = PyBytes_Size(py_key); |
100 |
+ |
101 |
+ arcfour_crypt_blob(data.data, data.length, &key); |
102 |
+ |
103 |
+ result = PyBytes_FromStringAndSize((const char*) data.data, data.length); |
104 |
+ talloc_free(ctx); |
105 |
+ return result; |
106 |
+} |
107 |
+ |
108 |
+ |
109 |
+static const char py_crypto_arcfour_crypt_blob_doc[] = "arcfour_crypt_blob(data, key)\n" |
110 |
+ "Encrypt the data with RC4 algorithm using the key"; |
111 |
+ |
112 |
+static PyMethodDef py_crypto_methods[] = { |
113 |
+ { "arcfour_crypt_blob", (PyCFunction)py_crypto_arcfour_crypt_blob, METH_VARARGS, py_crypto_arcfour_crypt_blob_doc }, |
114 |
+ { NULL }, |
115 |
+}; |
116 |
+ |
117 |
+static struct PyModuleDef moduledef = { |
118 |
+ PyModuleDef_HEAD_INIT, |
119 |
+ .m_name = "crypto", |
120 |
+ .m_doc = "Crypto functions required for SMB", |
121 |
+ .m_size = -1, |
122 |
+ .m_methods = py_crypto_methods, |
123 |
+}; |
124 |
+ |
125 |
+MODULE_INIT_FUNC(crypto) |
126 |
+{ |
127 |
+ PyObject *m; |
128 |
+ |
129 |
+ m = PyModule_Create(&moduledef); |
130 |
+ if (m == NULL) |
131 |
+ return NULL; |
132 |
+ |
133 |
+ return m; |
134 |
+} |
135 |
diff --git a/lib/crypto/wscript_build b/lib/crypto/wscript_build |
136 |
index 7f94532..d1f152e 100644 |
137 |
--- a/lib/crypto/wscript_build |
138 |
+++ b/lib/crypto/wscript_build |
139 |
@@ -25,3 +25,10 @@ bld.SAMBA_SUBSYSTEM('TORTURE_LIBCRYPTO', |
140 |
autoproto='test_proto.h', |
141 |
deps='LIBCRYPTO' |
142 |
) |
143 |
+ |
144 |
+for env in bld.gen_python_environments(): |
145 |
+ bld.SAMBA_PYTHON('python_crypto', |
146 |
+ source='py_crypto.c', |
147 |
+ deps='LIBCRYPTO', |
148 |
+ realname='samba/crypto.so' |
149 |
+ ) |
150 |
diff --git a/python/samba/__init__.py b/python/samba/__init__.py |
151 |
index 19d5e38..fa4244a 100644 |
152 |
--- a/python/samba/__init__.py |
153 |
+++ b/python/samba/__init__.py |
154 |
@@ -371,20 +371,8 @@ def string_to_byte_array(string): |
155 |
return blob |
156 |
|
157 |
def arcfour_encrypt(key, data): |
158 |
- try: |
159 |
- from Crypto.Cipher import ARC4 |
160 |
- c = ARC4.new(key) |
161 |
- return c.encrypt(data) |
162 |
- except ImportError as e: |
163 |
- pass |
164 |
- try: |
165 |
- from M2Crypto.RC4 import RC4 |
166 |
- c = RC4(key) |
167 |
- return c.update(data) |
168 |
- except ImportError as e: |
169 |
- pass |
170 |
- raise Exception("arcfour_encrypt() requires " + |
171 |
- "python*-crypto or python*-m2crypto or m2crypto") |
172 |
+ from samba.crypto import arcfour_crypt_blob |
173 |
+ return arcfour_crypt_blob(data, key) |
174 |
|
175 |
import _glue |
176 |
version = _glue.version |
177 |
-- |
178 |
2.9.3 |
179 |
|