lib/crypto/py_crypto.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    Samba crypto functions
   4
   5    Copyright (C) Alexander Bokovoy <ab@samba.org> 2017
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19 */
  20
  21 #include <Python.h>
  22 #include "includes.h"
  23 #include "python/py3compat.h"
  24
  25 #include <gnutls/gnutls.h>
  26 #include <gnutls/crypto.h>
  27 #include "lib/crypto/gnutls_helpers.h"
  28
  29 static PyObject *py_crypto_arcfour_crypt_blob(PyObject *module, PyObject *args)
  30 {
  31         DATA_BLOB data;
  32         PyObject *py_data, *py_key, *result;
  33         TALLOC_CTX *ctx;
  34         gnutls_cipher_hd_t cipher_hnd = NULL;
  35         gnutls_datum_t key;
  36         int rc;
  37
  38         if (!PyArg_ParseTuple(args, "OO", &py_data, &py_key))
  39                 return NULL;
  40
  41         if (!PyBytes_Check(py_data)) {
  42                 PyErr_Format(PyExc_TypeError, "bytes expected");
  43                 return NULL;
  44         }
  45
  46         if (!PyBytes_Check(py_key)) {
  47                 PyErr_Format(PyExc_TypeError, "bytes expected");
  48                 return NULL;
  49         }
  50
  51         ctx = talloc_new(NULL);
  52
  53         data.length = PyBytes_Size(py_data);
  54         data.data = talloc_memdup(ctx, PyBytes_AsString(py_data), data.length);
  55         if (!data.data) {
  56                 talloc_free(ctx);
  57                 return PyErr_NoMemory();
  58         }
  59
  60         key = (gnutls_datum_t) {
  61                 .data = (uint8_t *)PyBytes_AsString(py_key),
  62                 .size = PyBytes_Size(py_key),
  63         };
  64
  65         rc = gnutls_cipher_init(&cipher_hnd,
  66                                 GNUTLS_CIPHER_ARCFOUR_128,
  67                                 &key,
  68                                 NULL);
  69         if (rc < 0) {
  70                 talloc_free(ctx);
  71                 PyErr_Format(PyExc_OSError, "encryption failed");
  72                 return NULL;
  73         }
  74         rc = gnutls_cipher_encrypt(cipher_hnd,
  75                                    data.data,
  76                                    data.length);
  77         gnutls_cipher_deinit(cipher_hnd);
  78         if (rc < 0) {
  79                 talloc_free(ctx);
  80                 PyErr_Format(PyExc_OSError, "encryption failed");
  81                 return NULL;
  82         }
  83
  84         result = PyBytes_FromStringAndSize((const char*) data.data, data.length);
  85         talloc_free(ctx);
  86         return result;
  87 }
  88
  89 static PyObject *py_crypto_set_relax_mode(PyObject *module)
  90 {
  91         GNUTLS_FIPS140_SET_LAX_MODE();
  92
  93         Py_RETURN_NONE;
  94 }
  95
  96 static PyObject *py_crypto_set_strict_mode(PyObject *module)
  97 {
  98         GNUTLS_FIPS140_SET_STRICT_MODE();
  99
 100         Py_RETURN_NONE;
 101 }
 102
 103 static const char py_crypto_arcfour_crypt_blob_doc[] = "arcfour_crypt_blob(data, key)\n"
 104                                          "Encrypt the data with RC4 algorithm using the key";
 105
 106 static PyMethodDef py_crypto_methods[] = {
 107         { "arcfour_crypt_blob", (PyCFunction)py_crypto_arcfour_crypt_blob, METH_VARARGS, py_crypto_arcfour_crypt_blob_doc },
 108         { "set_relax_mode", (PyCFunction)py_crypto_set_relax_mode, METH_NOARGS, "Set fips to relax mode" },
 109         { "set_strict_mode", (PyCFunction)py_crypto_set_strict_mode, METH_NOARGS, "Set fips to strict mode" },
 110         {0},
 111 };
 112
 113 static struct PyModuleDef moduledef = {
 114         PyModuleDef_HEAD_INIT,
 115         .m_name = "crypto",
 116         .m_doc = "Crypto functions required for SMB",
 117         .m_size = -1,
 118         .m_methods = py_crypto_methods,
 119 };
 120
 121 MODULE_INIT_FUNC(crypto)
 122 {
 123         PyObject *m;
 124
 125         m = PyModule_Create(&moduledef);
 126         if (m == NULL)
 127                 return NULL;
 128
 129         return m;
 130 }