root/camellia/trunk/ccamellia.c

#include <Python.h>
#include <string.h>
#include <assert.h>
#include "camellia.h"

/*
 * ccamellia.c v 0.0
 * 
 * http://omake.accense.com/wiki/PythonCamellia
 * 
 * Copyright (c) 2006, Accense Technology, Inc.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * o Redistributions of source code must retain the above copyright notice, this
 *   list of conditions and the following disclaimer.
 * o Redistributions in binary form must reproduce the above copyright notice,
 *   this list of conditions and the following disclaimer in the documentation
 *   and/or other materials provided with the distribution. 
 * o Neither the name of the Accense Technology, Inc. nor the names of its
 *   contributors may be used to endorse or promote products derived from this
 *   software without specific prior written permission. 
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 */


/*
 * def Ekeygen(rawKey):
 *   return keyTable
 *
 * rawKey: 16 characters string
 * keyTable: 204 or 272 characters string
 */
static PyObject *
Ekeygen(PyObject* self, PyObject* args) {
  const char* rawKey;
  int length;
  unsigned int keyTable[68];

  if (!PyArg_ParseTuple(args, "s#", &rawKey, &length))
    return 0;

  switch (length) {
  case 16:
  case 24:
  case 32:
    break;

  default:
    /* raise ValueError, 'rawKey must be 16, 24 or 32 characters length.' */
    PyErr_SetString(PyExc_ValueError,
        "rawKey must be 16, 24 or 32 characters length.");
    return 0;
  }

  memset(keyTable, 0, sizeof (keyTable));
  Camellia_Ekeygen(length * 8, rawKey, keyTable);
  return PyString_FromStringAndSize(
      (const char*)&keyTable[0], (length == 16 ? 52*4 : 68*4));
}


/*
 * def EncryptBlock(plainText, keyTable):
 *   return cipherText
 *
 * plainText: 16 characters string
 * keyTable: 204 or 272 characters string
 * cipherText: 16 characters string
 */
static PyObject *
EncryptBlock(PyObject* self, PyObject* args) {
  const char* plainText;
  const unsigned int* keyTable;
  int len1, len2;
  char* cipherText;
  PyObject* o;

  if (!PyArg_ParseTuple(args, "s#s#", &plainText, &len1, &keyTable, &len2))
    return 0;
  if (len1 != 16) {
    PyErr_SetString(PyExc_ValueError, "plainText must be 16 characters");
    return 0;
  }

  o = PyString_FromStringAndSize(0, 16);
  PyString_AsStringAndSize(o, &cipherText, &len1);
  assert(len1 == 16);

  switch (len2) {
  case 52*4:
    /* keyBitLength 128 */
    Camellia_EncryptBlock(128, plainText, keyTable, cipherText);
    return o;

  case 68*4:
    /* keyBitLength 192 or 256; don't worry about '256' below. */
    Camellia_EncryptBlock(256, plainText, keyTable, cipherText);
    return o;

  default:
    Py_DECREF(o);
    PyErr_SetString(PyExc_ValueError, "keyTable must be 52 or 68 characters");
    return 0;
  }
}


/*
 * def DecryptBlock(cipherText, keyTable):
 *   return plainText
 *
 * cipherText: 16 characters string
 * keyTable: 204 or 272 characters string
 * plainText: 16 characters string
 */
static PyObject *
DecryptBlock(PyObject* self, PyObject* args) {
  const char* cipherText;
  const unsigned int* keyTable;
  int len1, len2;
  char* plainText;
  PyObject* o;

  if (!PyArg_ParseTuple(args, "s#s#", &cipherText, &len1, &keyTable, &len2))
    return 0;
  if (len1 != 16) {
    PyErr_SetString(PyExc_ValueError, "cipherText must be 16 characters");
    return 0;
  }

  o = PyString_FromStringAndSize(0, 16);
  PyString_AsStringAndSize(o, &plainText, &len1);
  assert(len1 == 16);

  switch (len2) {
  case 52*4:
    /* keyBitLength 128 */
    Camellia_DecryptBlock(128, cipherText, keyTable, plainText);
    return o;

  case 68*4:
    /* keyBitLength 192 or 256; don't worry about '256' below. */
    Camellia_DecryptBlock(256, cipherText, keyTable, plainText);
    return o;

  default:
    Py_DECREF(o);
    PyErr_SetString(PyExc_ValueError, "keyTable must be 52 or 68 characters");
    return 0;
  }
}


static PyMethodDef methodTable[] = {
  /* XXX help string */
  { "Ekeygen", Ekeygen, METH_VARARGS, "Generate keyTable from key string." },
  { "EncryptBlock", EncryptBlock, METH_VARARGS, "EncryptBlock" },
  { "DecryptBlock", DecryptBlock, METH_VARARGS, "DecryptBlock" },
  { 0, 0, 0, 0 }
};

PyMODINIT_FUNC
initccamellia(void) {
  (void)Py_InitModule("ccamellia", methodTable);
}