Modules/md5module.c - platform/external/python/cpython3 - Gitiles

 /* MD5 module */

 /* This module provides an interface to the MD5 algorithm */

 /* See below for information about the original code this module was
    based upon. Additional work performed by:

    Andrew Kuchling (amk@amk.ca)
    Greg Stein (gstein@lyra.org)
    Trevor Perrin (trevp@trevp.net)

    Copyright (C) 2005-2007   Gregory P. Smith (greg@krypto.org)
    Licensed to PSF under a Contributor Agreement.

 */

 /* MD5 objects */

 #include "Python.h"
 #include "hashlib.h"


 /* Some useful types */

 #if SIZEOF_INT == 4
 typedef unsigned int MD5_INT32; /* 32-bit integer */
 typedef PY_LONG_LONG MD5_INT64; /* 64-bit integer */
 #else
 /* not defined. compilation will die. */
 #endif

 /* The MD5 block size and message digest sizes, in bytes */

 #define MD5_BLOCKSIZE    64
 #define MD5_DIGESTSIZE   16

 /* The structure for storing MD5 info */

 struct md5_state {
     MD5_INT64 length;
     MD5_INT32 state[4], curlen;
     unsigned char buf[MD5_BLOCKSIZE];
 };

 typedef struct {
     PyObject_HEAD

     struct md5_state hash_state;
 } MD5object;


 /* ------------------------------------------------------------------------
  *
  * This code for the MD5 algorithm was noted as public domain. The
  * original headers are pasted below.
  *
  * Several changes have been made to make it more compatible with the
  * Python environment and desired interface.
  *
  */

 /* LibTomCrypt, modular cryptographic library -- Tom St Denis
  *
  * LibTomCrypt is a library that provides various cryptographic
  * algorithms in a highly modular and flexible manner.
  *
  * The library is free for all purposes without any express
  * guarantee it works.
  *
  * Tom St Denis, tomstdenis@gmail.com, http://libtom.org
  */

 /* rotate the hard way (platform optimizations could be done) */
 #define ROLc(x, y) ( (((unsigned long)(x)<<(unsigned long)((y)&31)) | (((unsigned long)(x)&0xFFFFFFFFUL)>>(unsigned long)(32-((y)&31)))) & 0xFFFFFFFFUL)

 /* Endian Neutral macros that work on all platforms */

 #define STORE32L(x, y)                                                                     \
      { (y)[3] = (unsigned char)(((x)>>24)&255); (y)[2] = (unsigned char)(((x)>>16)&255);   \
        (y)[1] = (unsigned char)(((x)>>8)&255); (y)[0] = (unsigned char)((x)&255); }

 #define LOAD32L(x, y)                            \
      { x = ((unsigned long)((y)[3] & 255)<<24) | \
            ((unsigned long)((y)[2] & 255)<<16) | \
            ((unsigned long)((y)[1] & 255)<<8)  | \
            ((unsigned long)((y)[0] & 255)); }

 #define STORE64L(x, y)                                                                     \
      { (y)[7] = (unsigned char)(((x)>>56)&255); (y)[6] = (unsigned char)(((x)>>48)&255);   \
        (y)[5] = (unsigned char)(((x)>>40)&255); (y)[4] = (unsigned char)(((x)>>32)&255);   \
        (y)[3] = (unsigned char)(((x)>>24)&255); (y)[2] = (unsigned char)(((x)>>16)&255);   \
        (y)[1] = (unsigned char)(((x)>>8)&255); (y)[0] = (unsigned char)((x)&255); }

 #ifndef MIN
    #define MIN(x, y) ( ((x)<(y))?(x):(y) )
 #endif


 /* MD5 macros */

 #define F(x,y,z)  (z ^ (x & (y ^ z)))
 #define G(x,y,z)  (y ^ (z & (y ^ x)))
 #define H(x,y,z)  (x^y^z)
 #define I(x,y,z)  (y^(x|(~z)))

 #define FF(a,b,c,d,M,s,t) \
     a = (a + F(b,c,d) + M + t); a = ROLc(a, s) + b;

 #define GG(a,b,c,d,M,s,t) \
     a = (a + G(b,c,d) + M + t); a = ROLc(a, s) + b;

 #define HH(a,b,c,d,M,s,t) \
     a = (a + H(b,c,d) + M + t); a = ROLc(a, s) + b;

 #define II(a,b,c,d,M,s,t) \
     a = (a + I(b,c,d) + M + t); a = ROLc(a, s) + b;


 static void md5_compress(struct md5_state *md5, unsigned char *buf)
 {
     MD5_INT32 i, W[16], a, b, c, d;

     assert(md5 != NULL);
     assert(buf != NULL);

     /* copy the state into 512-bits into W[0..15] */
     for (i = 0; i < 16; i++) {
         LOAD32L(W[i], buf + (4*i));
     }

     /* copy state */
     a = md5->state[0];
     b = md5->state[1];
     c = md5->state[2];
     d = md5->state[3];

     FF(a,b,c,d,W[0],7,0xd76aa478UL)
     FF(d,a,b,c,W[1],12,0xe8c7b756UL)
     FF(c,d,a,b,W[2],17,0x242070dbUL)
     FF(b,c,d,a,W[3],22,0xc1bdceeeUL)
     FF(a,b,c,d,W[4],7,0xf57c0fafUL)
     FF(d,a,b,c,W[5],12,0x4787c62aUL)
     FF(c,d,a,b,W[6],17,0xa8304613UL)
     FF(b,c,d,a,W[7],22,0xfd469501UL)
     FF(a,b,c,d,W[8],7,0x698098d8UL)
     FF(d,a,b,c,W[9],12,0x8b44f7afUL)
     FF(c,d,a,b,W[10],17,0xffff5bb1UL)
     FF(b,c,d,a,W[11],22,0x895cd7beUL)
     FF(a,b,c,d,W[12],7,0x6b901122UL)
     FF(d,a,b,c,W[13],12,0xfd987193UL)
     FF(c,d,a,b,W[14],17,0xa679438eUL)
     FF(b,c,d,a,W[15],22,0x49b40821UL)
     GG(a,b,c,d,W[1],5,0xf61e2562UL)
     GG(d,a,b,c,W[6],9,0xc040b340UL)
     GG(c,d,a,b,W[11],14,0x265e5a51UL)
     GG(b,c,d,a,W[0],20,0xe9b6c7aaUL)
     GG(a,b,c,d,W[5],5,0xd62f105dUL)
     GG(d,a,b,c,W[10],9,0x02441453UL)
     GG(c,d,a,b,W[15],14,0xd8a1e681UL)
     GG(b,c,d,a,W[4],20,0xe7d3fbc8UL)
     GG(a,b,c,d,W[9],5,0x21e1cde6UL)
     GG(d,a,b,c,W[14],9,0xc33707d6UL)
     GG(c,d,a,b,W[3],14,0xf4d50d87UL)
     GG(b,c,d,a,W[8],20,0x455a14edUL)
     GG(a,b,c,d,W[13],5,0xa9e3e905UL)
     GG(d,a,b,c,W[2],9,0xfcefa3f8UL)
     GG(c,d,a,b,W[7],14,0x676f02d9UL)
     GG(b,c,d,a,W[12],20,0x8d2a4c8aUL)
     HH(a,b,c,d,W[5],4,0xfffa3942UL)
     HH(d,a,b,c,W[8],11,0x8771f681UL)
     HH(c,d,a,b,W[11],16,0x6d9d6122UL)
     HH(b,c,d,a,W[14],23,0xfde5380cUL)
     HH(a,b,c,d,W[1],4,0xa4beea44UL)
     HH(d,a,b,c,W[4],11,0x4bdecfa9UL)
     HH(c,d,a,b,W[7],16,0xf6bb4b60UL)
     HH(b,c,d,a,W[10],23,0xbebfbc70UL)
     HH(a,b,c,d,W[13],4,0x289b7ec6UL)
     HH(d,a,b,c,W[0],11,0xeaa127faUL)
     HH(c,d,a,b,W[3],16,0xd4ef3085UL)
     HH(b,c,d,a,W[6],23,0x04881d05UL)
     HH(a,b,c,d,W[9],4,0xd9d4d039UL)
     HH(d,a,b,c,W[12],11,0xe6db99e5UL)
     HH(c,d,a,b,W[15],16,0x1fa27cf8UL)
     HH(b,c,d,a,W[2],23,0xc4ac5665UL)
     II(a,b,c,d,W[0],6,0xf4292244UL)
     II(d,a,b,c,W[7],10,0x432aff97UL)
     II(c,d,a,b,W[14],15,0xab9423a7UL)
     II(b,c,d,a,W[5],21,0xfc93a039UL)
     II(a,b,c,d,W[12],6,0x655b59c3UL)
     II(d,a,b,c,W[3],10,0x8f0ccc92UL)
     II(c,d,a,b,W[10],15,0xffeff47dUL)
     II(b,c,d,a,W[1],21,0x85845dd1UL)
     II(a,b,c,d,W[8],6,0x6fa87e4fUL)
     II(d,a,b,c,W[15],10,0xfe2ce6e0UL)
     II(c,d,a,b,W[6],15,0xa3014314UL)
     II(b,c,d,a,W[13],21,0x4e0811a1UL)
     II(a,b,c,d,W[4],6,0xf7537e82UL)
     II(d,a,b,c,W[11],10,0xbd3af235UL)
     II(c,d,a,b,W[2],15,0x2ad7d2bbUL)
     II(b,c,d,a,W[9],21,0xeb86d391UL)

     md5->state[0] = md5->state[0] + a;
     md5->state[1] = md5->state[1] + b;
     md5->state[2] = md5->state[2] + c;
     md5->state[3] = md5->state[3] + d;
 }


 /**
    Initialize the hash state
    @param sha1   The hash state you wish to initialize
 */
 void md5_init(struct md5_state *md5)
 {
     assert(md5 != NULL);
     md5->state[0] = 0x67452301UL;
     md5->state[1] = 0xefcdab89UL;
     md5->state[2] = 0x98badcfeUL;
     md5->state[3] = 0x10325476UL;
     md5->curlen = 0;
     md5->length = 0;
 }

 /**
    Process a block of memory though the hash
    @param sha1   The hash state
    @param in     The data to hash
    @param inlen  The length of the data (octets)
 */
 void md5_process(struct md5_state *md5,
                 const unsigned char *in, Py_ssize_t inlen)
 {
     Py_ssize_t n;

     assert(md5 != NULL);
     assert(in != NULL);
     assert(md5->curlen <= sizeof(md5->buf));

     while (inlen > 0) {
         if (md5->curlen == 0 && inlen >= MD5_BLOCKSIZE) {
            md5_compress(md5, (unsigned char *)in);
            md5->length    += MD5_BLOCKSIZE * 8;
            in             += MD5_BLOCKSIZE;
            inlen          -= MD5_BLOCKSIZE;
         } else {
            n = MIN(inlen, (MD5_BLOCKSIZE - md5->curlen));
            memcpy(md5->buf + md5->curlen, in, (size_t)n);
            md5->curlen    += n;
            in             += n;
            inlen          -= n;
            if (md5->curlen == MD5_BLOCKSIZE) {
               md5_compress(md5, md5->buf);
               md5->length += 8*MD5_BLOCKSIZE;
               md5->curlen = 0;
            }
        }
     }
 }

 /**
    Terminate the hash to get the digest
    @param sha1  The hash state
    @param out [out] The destination of the hash (16 bytes)
 */
 void md5_done(struct md5_state *md5, unsigned char *out)
 {
     int i;

     assert(md5 != NULL);
     assert(out != NULL);
     assert(md5->curlen < sizeof(md5->buf));

     /* increase the length of the message */
     md5->length += md5->curlen * 8;

     /* append the '1' bit */
     md5->buf[md5->curlen++] = (unsigned char)0x80;

     /* if the length is currently above 56 bytes we append zeros
      * then compress.  Then we can fall back to padding zeros and length
      * encoding like normal.
      */
     if (md5->curlen > 56) {
         while (md5->curlen < 64) {
             md5->buf[md5->curlen++] = (unsigned char)0;
         }
         md5_compress(md5, md5->buf);
         md5->curlen = 0;
     }

     /* pad upto 56 bytes of zeroes */
     while (md5->curlen < 56) {
         md5->buf[md5->curlen++] = (unsigned char)0;
     }

     /* store length */
     STORE64L(md5->length, md5->buf+56);
     md5_compress(md5, md5->buf);

     /* copy output */
     for (i = 0; i < 4; i++) {
         STORE32L(md5->state[i], out+(4*i));
     }
 }

 /* .Source: /cvs/libtom/libtomcrypt/src/hashes/md5.c,v $ */
 /* .Revision: 1.10 $ */
 /* .Date: 2007/05/12 14:25:28 $ */

 /*
  * End of copied MD5 code.
  *
  * ------------------------------------------------------------------------
  */

 static PyTypeObject MD5type;


 static MD5object *
 newMD5object(void)
 {
     return (MD5object *)PyObject_New(MD5object, &MD5type);
 }


 /* Internal methods for a hash object */

 static void
 MD5_dealloc(PyObject *ptr)
 {
     PyObject_Del(ptr);
 }


 /* External methods for a hash object */

 PyDoc_STRVAR(MD5_copy__doc__, "Return a copy of the hash object.");

 static PyObject *
 MD5_copy(MD5object *self, PyObject *unused)
 {
     MD5object *newobj;

     if (Py_TYPE(self) == &MD5type) {
         if ( (newobj = newMD5object())==NULL)
             return NULL;
     } else {
         if ( (newobj = newMD5object())==NULL)
             return NULL;
     }

     newobj->hash_state = self->hash_state;
     return (PyObject *)newobj;
 }

 PyDoc_STRVAR(MD5_digest__doc__,
 "Return the digest value as a string of binary data.");

 static PyObject *
 MD5_digest(MD5object *self, PyObject *unused)
 {
     unsigned char digest[MD5_DIGESTSIZE];
     struct md5_state temp;

     temp = self->hash_state;
     md5_done(&temp, digest);
     return PyBytes_FromStringAndSize((const char *)digest, MD5_DIGESTSIZE);
 }

 PyDoc_STRVAR(MD5_hexdigest__doc__,
 "Return the digest value as a string of hexadecimal digits.");

 static PyObject *
 MD5_hexdigest(MD5object *self, PyObject *unused)
 {
     unsigned char digest[MD5_DIGESTSIZE];
     struct md5_state temp;
     PyObject *retval;
     Py_UNICODE *hex_digest;
     int i, j;

     /* Get the raw (binary) digest value */
     temp = self->hash_state;
     md5_done(&temp, digest);

     /* Create a new string */
     retval = PyUnicode_FromStringAndSize(NULL, MD5_DIGESTSIZE * 2);
     if (!retval)
             return NULL;
     hex_digest = PyUnicode_AS_UNICODE(retval);
     if (!hex_digest) {
             Py_DECREF(retval);
             return NULL;
     }

     /* Make hex version of the digest */
     for(i=j=0; i<MD5_DIGESTSIZE; i++) {
         char c;
         c = (digest[i] >> 4) & 0xf;
         c = (c>9) ? c+'a'-10 : c + '0';
         hex_digest[j++] = c;
         c = (digest[i] & 0xf);
         c = (c>9) ? c+'a'-10 : c + '0';
         hex_digest[j++] = c;
     }
     return retval;
 }

 PyDoc_STRVAR(MD5_update__doc__,
 "Update this hash object's state with the provided string.");

 static PyObject *
 MD5_update(MD5object *self, PyObject *args)
 {
     PyObject *obj;
     Py_buffer buf;

     if (!PyArg_ParseTuple(args, "O:update", &obj))
         return NULL;

     GET_BUFFER_VIEW_OR_ERROUT(obj, &buf);

     md5_process(&self->hash_state, buf.buf, buf.len);

     PyBuffer_Release(&buf);
     Py_INCREF(Py_None);
     return Py_None;
 }

 static PyMethodDef MD5_methods[] = {
     {"copy",      (PyCFunction)MD5_copy,      METH_NOARGS,  MD5_copy__doc__},
     {"digest",    (PyCFunction)MD5_digest,    METH_NOARGS,  MD5_digest__doc__},
     {"hexdigest", (PyCFunction)MD5_hexdigest, METH_NOARGS,  MD5_hexdigest__doc__},
     {"update",    (PyCFunction)MD5_update,    METH_VARARGS, MD5_update__doc__},
     {NULL,        NULL}         /* sentinel */
 };

 static PyObject *
 MD5_get_block_size(PyObject *self, void *closure)
 {
     return PyLong_FromLong(MD5_BLOCKSIZE);
 }

 static PyObject *
 MD5_get_name(PyObject *self, void *closure)
 {
     return PyUnicode_FromStringAndSize("MD5", 3);
 }

 static PyObject *
 md5_get_digest_size(PyObject *self, void *closure)
 {
     return PyLong_FromLong(MD5_DIGESTSIZE);
 }


 static PyGetSetDef MD5_getseters[] = {
     {"block_size",
      (getter)MD5_get_block_size, NULL,
      NULL,
      NULL},
     {"name",
      (getter)MD5_get_name, NULL,
      NULL,
      NULL},
     {"digest_size",
      (getter)md5_get_digest_size, NULL,
      NULL,
      NULL},
     {NULL}  /* Sentinel */
 };

 static PyTypeObject MD5type = {
     PyVarObject_HEAD_INIT(NULL, 0)
     "_md5.md5",         /*tp_name*/
     sizeof(MD5object),  /*tp_size*/
     0,                  /*tp_itemsize*/
     /* methods */
     MD5_dealloc,        /*tp_dealloc*/
     0,                  /*tp_print*/
     0,                  /*tp_getattr*/
     0,                  /*tp_setattr*/
     0,                  /*tp_reserved*/
     0,                  /*tp_repr*/
     0,                  /*tp_as_number*/
     0,                  /*tp_as_sequence*/
     0,                  /*tp_as_mapping*/
     0,                  /*tp_hash*/
     0,                  /*tp_call*/
     0,                  /*tp_str*/
     0,                  /*tp_getattro*/
     0,                  /*tp_setattro*/
     0,                  /*tp_as_buffer*/
     Py_TPFLAGS_DEFAULT, /*tp_flags*/
     0,                  /*tp_doc*/
     0,                  /*tp_traverse*/
     0,                  /*tp_clear*/
     0,                  /*tp_richcompare*/
     0,                  /*tp_weaklistoffset*/
     0,                  /*tp_iter*/
     0,                  /*tp_iternext*/
     MD5_methods,        /* tp_methods */
     NULL,               /* tp_members */
     MD5_getseters,      /* tp_getset */
 };


 /* The single module-level function: new() */

 PyDoc_STRVAR(MD5_new__doc__,
 "Return a new MD5 hash object; optionally initialized with a string.");

 static PyObject *
 MD5_new(PyObject *self, PyObject *args, PyObject *kwdict)
 {
     static char *kwlist[] = {"string", NULL};
     MD5object *new;
     PyObject *data_obj = NULL;
     Py_buffer buf;

     if (!PyArg_ParseTupleAndKeywords(args, kwdict, "|O:new", kwlist,
                                      &data_obj)) {
         return NULL;
     }

     if (data_obj)
         GET_BUFFER_VIEW_OR_ERROUT(data_obj, &buf);

     if ((new = newMD5object()) == NULL) {
         if (data_obj)
             PyBuffer_Release(&buf);
         return NULL;
     }

     md5_init(&new->hash_state);

     if (PyErr_Occurred()) {
         Py_DECREF(new);
         if (data_obj)
             PyBuffer_Release(&buf);
         return NULL;
     }
     if (data_obj) {
         md5_process(&new->hash_state, buf.buf, buf.len);
         PyBuffer_Release(&buf);
     }

     return (PyObject *)new;
 }


 /* List of functions exported by this module */

 static struct PyMethodDef MD5_functions[] = {
     {"md5", (PyCFunction)MD5_new, METH_VARARGS|METH_KEYWORDS, MD5_new__doc__},
     {NULL,      NULL}            /* Sentinel */
 };


 /* Initialize this module. */

 #define insint(n,v) { PyModule_AddIntConstant(m,n,v); }


 static struct PyModuleDef _md5module = {
         PyModuleDef_HEAD_INIT,
         "_md5",
         NULL,
         -1,
         MD5_functions,
         NULL,
         NULL,
         NULL,
         NULL
 };

 PyMODINIT_FUNC
 PyInit__md5(void)
 {
     Py_TYPE(&MD5type) = &PyType_Type;
     if (PyType_Ready(&MD5type) < 0)
         return NULL;
     return PyModule_Create(&_md5module);
 }
	/* MD5 module */

	/* This module provides an interface to the MD5 algorithm */

	/* See below for information about the original code this module was
	based upon. Additional work performed by:

	Andrew Kuchling (amk@amk.ca)
	Greg Stein (gstein@lyra.org)
	Trevor Perrin (trevp@trevp.net)

	Copyright (C) 2005-2007 Gregory P. Smith (greg@krypto.org)
	Licensed to PSF under a Contributor Agreement.

	*/

	/* MD5 objects */

	#include "Python.h"
	#include "hashlib.h"


	/* Some useful types */

	#if SIZEOF_INT == 4
	typedef unsigned int MD5_INT32; /* 32-bit integer */
	typedef PY_LONG_LONG MD5_INT64; /* 64-bit integer */
	#else
	/* not defined. compilation will die. */
	#endif

	/* The MD5 block size and message digest sizes, in bytes */

	#define MD5_BLOCKSIZE 64
	#define MD5_DIGESTSIZE 16

	/* The structure for storing MD5 info */

	struct md5_state {
	MD5_INT64 length;
	MD5_INT32 state[4], curlen;
	unsigned char buf[MD5_BLOCKSIZE];
	};

	typedef struct {
	PyObject_HEAD

	struct md5_state hash_state;
	} MD5object;


	/* ------------------------------------------------------------------------
	*
	* This code for the MD5 algorithm was noted as public domain. The
	* original headers are pasted below.
	*
	* Several changes have been made to make it more compatible with the
	* Python environment and desired interface.
	*
	*/

	/* LibTomCrypt, modular cryptographic library -- Tom St Denis
	*
	* LibTomCrypt is a library that provides various cryptographic
	* algorithms in a highly modular and flexible manner.
	*
	* The library is free for all purposes without any express
	* guarantee it works.
	*
	* Tom St Denis, tomstdenis@gmail.com, http://libtom.org
	*/

	/* rotate the hard way (platform optimizations could be done) */
	#define ROLc(x, y) ( (((unsigned long)(x)<<(unsigned long)((y)&31)) \| (((unsigned long)(x)&0xFFFFFFFFUL)>>(unsigned long)(32-((y)&31)))) & 0xFFFFFFFFUL)

	/* Endian Neutral macros that work on all platforms */

	#define STORE32L(x, y) \
	{ (y)[3] = (unsigned char)(((x)>>24)&255); (y)[2] = (unsigned char)(((x)>>16)&255); \
	(y)[1] = (unsigned char)(((x)>>8)&255); (y)[0] = (unsigned char)((x)&255); }

	#define LOAD32L(x, y) \
	{ x = ((unsigned long)((y)[3] & 255)<<24) \| \
	((unsigned long)((y)[2] & 255)<<16) \| \
	((unsigned long)((y)[1] & 255)<<8) \| \
	((unsigned long)((y)[0] & 255)); }

	#define STORE64L(x, y) \
	{ (y)[7] = (unsigned char)(((x)>>56)&255); (y)[6] = (unsigned char)(((x)>>48)&255); \
	(y)[5] = (unsigned char)(((x)>>40)&255); (y)[4] = (unsigned char)(((x)>>32)&255); \
	(y)[3] = (unsigned char)(((x)>>24)&255); (y)[2] = (unsigned char)(((x)>>16)&255); \
	(y)[1] = (unsigned char)(((x)>>8)&255); (y)[0] = (unsigned char)((x)&255); }

	#ifndef MIN
	#define MIN(x, y) ( ((x)<(y))?(x):(y) )
	#endif


	/* MD5 macros */

	#define F(x,y,z) (z ^ (x & (y ^ z)))
	#define G(x,y,z) (y ^ (z & (y ^ x)))
	#define H(x,y,z) (x^y^z)
	#define I(x,y,z) (y^(x\|(~z)))

	#define FF(a,b,c,d,M,s,t) \
	a = (a + F(b,c,d) + M + t); a = ROLc(a, s) + b;

	#define GG(a,b,c,d,M,s,t) \
	a = (a + G(b,c,d) + M + t); a = ROLc(a, s) + b;

	#define HH(a,b,c,d,M,s,t) \
	a = (a + H(b,c,d) + M + t); a = ROLc(a, s) + b;

	#define II(a,b,c,d,M,s,t) \
	a = (a + I(b,c,d) + M + t); a = ROLc(a, s) + b;


	static void md5_compress(struct md5_state md5, unsigned char buf)
	{
	MD5_INT32 i, W[16], a, b, c, d;

	assert(md5 != NULL);
	assert(buf != NULL);

	/* copy the state into 512-bits into W[0..15] */
	for (i = 0; i < 16; i++) {
	LOAD32L(W[i], buf + (4*i));
	}

	/* copy state */
	a = md5->state[0];
	b = md5->state[1];
	c = md5->state[2];
	d = md5->state[3];

	FF(a,b,c,d,W[0],7,0xd76aa478UL)
	FF(d,a,b,c,W[1],12,0xe8c7b756UL)
	FF(c,d,a,b,W[2],17,0x242070dbUL)
	FF(b,c,d,a,W[3],22,0xc1bdceeeUL)
	FF(a,b,c,d,W[4],7,0xf57c0fafUL)
	FF(d,a,b,c,W[5],12,0x4787c62aUL)
	FF(c,d,a,b,W[6],17,0xa8304613UL)
	FF(b,c,d,a,W[7],22,0xfd469501UL)
	FF(a,b,c,d,W[8],7,0x698098d8UL)
	FF(d,a,b,c,W[9],12,0x8b44f7afUL)
	FF(c,d,a,b,W[10],17,0xffff5bb1UL)
	FF(b,c,d,a,W[11],22,0x895cd7beUL)
	FF(a,b,c,d,W[12],7,0x6b901122UL)
	FF(d,a,b,c,W[13],12,0xfd987193UL)
	FF(c,d,a,b,W[14],17,0xa679438eUL)
	FF(b,c,d,a,W[15],22,0x49b40821UL)
	GG(a,b,c,d,W[1],5,0xf61e2562UL)
	GG(d,a,b,c,W[6],9,0xc040b340UL)
	GG(c,d,a,b,W[11],14,0x265e5a51UL)
	GG(b,c,d,a,W[0],20,0xe9b6c7aaUL)
	GG(a,b,c,d,W[5],5,0xd62f105dUL)
	GG(d,a,b,c,W[10],9,0x02441453UL)
	GG(c,d,a,b,W[15],14,0xd8a1e681UL)
	GG(b,c,d,a,W[4],20,0xe7d3fbc8UL)
	GG(a,b,c,d,W[9],5,0x21e1cde6UL)
	GG(d,a,b,c,W[14],9,0xc33707d6UL)
	GG(c,d,a,b,W[3],14,0xf4d50d87UL)
	GG(b,c,d,a,W[8],20,0x455a14edUL)
	GG(a,b,c,d,W[13],5,0xa9e3e905UL)
	GG(d,a,b,c,W[2],9,0xfcefa3f8UL)
	GG(c,d,a,b,W[7],14,0x676f02d9UL)
	GG(b,c,d,a,W[12],20,0x8d2a4c8aUL)
	HH(a,b,c,d,W[5],4,0xfffa3942UL)
	HH(d,a,b,c,W[8],11,0x8771f681UL)
	HH(c,d,a,b,W[11],16,0x6d9d6122UL)
	HH(b,c,d,a,W[14],23,0xfde5380cUL)
	HH(a,b,c,d,W[1],4,0xa4beea44UL)
	HH(d,a,b,c,W[4],11,0x4bdecfa9UL)
	HH(c,d,a,b,W[7],16,0xf6bb4b60UL)
	HH(b,c,d,a,W[10],23,0xbebfbc70UL)
	HH(a,b,c,d,W[13],4,0x289b7ec6UL)
	HH(d,a,b,c,W[0],11,0xeaa127faUL)
	HH(c,d,a,b,W[3],16,0xd4ef3085UL)
	HH(b,c,d,a,W[6],23,0x04881d05UL)
	HH(a,b,c,d,W[9],4,0xd9d4d039UL)
	HH(d,a,b,c,W[12],11,0xe6db99e5UL)
	HH(c,d,a,b,W[15],16,0x1fa27cf8UL)
	HH(b,c,d,a,W[2],23,0xc4ac5665UL)
	II(a,b,c,d,W[0],6,0xf4292244UL)
	II(d,a,b,c,W[7],10,0x432aff97UL)
	II(c,d,a,b,W[14],15,0xab9423a7UL)
	II(b,c,d,a,W[5],21,0xfc93a039UL)
	II(a,b,c,d,W[12],6,0x655b59c3UL)
	II(d,a,b,c,W[3],10,0x8f0ccc92UL)
	II(c,d,a,b,W[10],15,0xffeff47dUL)
	II(b,c,d,a,W[1],21,0x85845dd1UL)
	II(a,b,c,d,W[8],6,0x6fa87e4fUL)
	II(d,a,b,c,W[15],10,0xfe2ce6e0UL)
	II(c,d,a,b,W[6],15,0xa3014314UL)
	II(b,c,d,a,W[13],21,0x4e0811a1UL)
	II(a,b,c,d,W[4],6,0xf7537e82UL)
	II(d,a,b,c,W[11],10,0xbd3af235UL)
	II(c,d,a,b,W[2],15,0x2ad7d2bbUL)
	II(b,c,d,a,W[9],21,0xeb86d391UL)

	md5->state[0] = md5->state[0] + a;
	md5->state[1] = md5->state[1] + b;
	md5->state[2] = md5->state[2] + c;
	md5->state[3] = md5->state[3] + d;
	}


	/**
	Initialize the hash state
	@param sha1 The hash state you wish to initialize
	*/
	void md5_init(struct md5_state *md5)
	{
	assert(md5 != NULL);
	md5->state[0] = 0x67452301UL;
	md5->state[1] = 0xefcdab89UL;
	md5->state[2] = 0x98badcfeUL;
	md5->state[3] = 0x10325476UL;
	md5->curlen = 0;
	md5->length = 0;
	}

	/**
	Process a block of memory though the hash
	@param sha1 The hash state
	@param in The data to hash
	@param inlen The length of the data (octets)
	*/
	void md5_process(struct md5_state *md5,
	const unsigned char *in, Py_ssize_t inlen)
	{
	Py_ssize_t n;

	assert(md5 != NULL);
	assert(in != NULL);
	assert(md5->curlen <= sizeof(md5->buf));

	while (inlen > 0) {
	if (md5->curlen == 0 && inlen >= MD5_BLOCKSIZE) {
	md5_compress(md5, (unsigned char *)in);
	md5->length += MD5_BLOCKSIZE * 8;
	in += MD5_BLOCKSIZE;
	inlen -= MD5_BLOCKSIZE;
	} else {
	n = MIN(inlen, (MD5_BLOCKSIZE - md5->curlen));
	memcpy(md5->buf + md5->curlen, in, (size_t)n);
	md5->curlen += n;
	in += n;
	inlen -= n;
	if (md5->curlen == MD5_BLOCKSIZE) {
	md5_compress(md5, md5->buf);
	md5->length += 8*MD5_BLOCKSIZE;
	md5->curlen = 0;
	}
	}
	}
	}

	/**
	Terminate the hash to get the digest
	@param sha1 The hash state
	@param out [out] The destination of the hash (16 bytes)
	*/
	void md5_done(struct md5_state md5, unsigned char out)
	{
	int i;

	assert(md5 != NULL);
	assert(out != NULL);
	assert(md5->curlen < sizeof(md5->buf));

	/* increase the length of the message */
	md5->length += md5->curlen * 8;

	/* append the '1' bit */
	md5->buf[md5->curlen++] = (unsigned char)0x80;

	/* if the length is currently above 56 bytes we append zeros
	* then compress. Then we can fall back to padding zeros and length
	* encoding like normal.
	*/
	if (md5->curlen > 56) {
	while (md5->curlen < 64) {
	md5->buf[md5->curlen++] = (unsigned char)0;
	}
	md5_compress(md5, md5->buf);
	md5->curlen = 0;
	}

	/* pad upto 56 bytes of zeroes */
	while (md5->curlen < 56) {
	md5->buf[md5->curlen++] = (unsigned char)0;
	}

	/* store length */
	STORE64L(md5->length, md5->buf+56);
	md5_compress(md5, md5->buf);

	/* copy output */
	for (i = 0; i < 4; i++) {
	STORE32L(md5->state[i], out+(4*i));
	}
	}

	/* .Source: /cvs/libtom/libtomcrypt/src/hashes/md5.c,v $ */
	/* .Revision: 1.10 $ */
	/* .Date: 2007/05/12 14:25:28 $ */

	/*
	* End of copied MD5 code.
	*
	* ------------------------------------------------------------------------
	*/

	static PyTypeObject MD5type;


	static MD5object *
	newMD5object(void)
	{
	return (MD5object *)PyObject_New(MD5object, &MD5type);
	}


	/* Internal methods for a hash object */

	static void
	MD5_dealloc(PyObject *ptr)
	{
	PyObject_Del(ptr);
	}


	/* External methods for a hash object */

	PyDoc_STRVAR(MD5_copy__doc__, "Return a copy of the hash object.");

	static PyObject *
	MD5_copy(MD5object self, PyObject unused)
	{
	MD5object *newobj;

	if (Py_TYPE(self) == &MD5type) {
	if ( (newobj = newMD5object())==NULL)
	return NULL;
	} else {
	if ( (newobj = newMD5object())==NULL)
	return NULL;
	}

	newobj->hash_state = self->hash_state;
	return (PyObject *)newobj;
	}

	PyDoc_STRVAR(MD5_digest__doc__,
	"Return the digest value as a string of binary data.");

	static PyObject *
	MD5_digest(MD5object self, PyObject unused)
	{
	unsigned char digest[MD5_DIGESTSIZE];
	struct md5_state temp;

	temp = self->hash_state;
	md5_done(&temp, digest);
	return PyBytes_FromStringAndSize((const char *)digest, MD5_DIGESTSIZE);
	}

	PyDoc_STRVAR(MD5_hexdigest__doc__,
	"Return the digest value as a string of hexadecimal digits.");

	static PyObject *
	MD5_hexdigest(MD5object self, PyObject unused)
	{
	unsigned char digest[MD5_DIGESTSIZE];
	struct md5_state temp;
	PyObject *retval;
	Py_UNICODE *hex_digest;
	int i, j;

	/* Get the raw (binary) digest value */
	temp = self->hash_state;
	md5_done(&temp, digest);

	/* Create a new string */
	retval = PyUnicode_FromStringAndSize(NULL, MD5_DIGESTSIZE * 2);
	if (!retval)
	return NULL;
	hex_digest = PyUnicode_AS_UNICODE(retval);
	if (!hex_digest) {
	Py_DECREF(retval);
	return NULL;
	}

	/* Make hex version of the digest */
	for(i=j=0; i<MD5_DIGESTSIZE; i++) {
	char c;
	c = (digest[i] >> 4) & 0xf;
	c = (c>9) ? c+'a'-10 : c + '0';
	hex_digest[j++] = c;
	c = (digest[i] & 0xf);
	c = (c>9) ? c+'a'-10 : c + '0';
	hex_digest[j++] = c;
	}
	return retval;
	}

	PyDoc_STRVAR(MD5_update__doc__,
	"Update this hash object's state with the provided string.");

	static PyObject *
	MD5_update(MD5object self, PyObject args)
	{
	PyObject *obj;
	Py_buffer buf;

	if (!PyArg_ParseTuple(args, "O:update", &obj))
	return NULL;

	GET_BUFFER_VIEW_OR_ERROUT(obj, &buf);

	md5_process(&self->hash_state, buf.buf, buf.len);

	PyBuffer_Release(&buf);
	Py_INCREF(Py_None);
	return Py_None;
	}

	static PyMethodDef MD5_methods[] = {
	{"copy", (PyCFunction)MD5_copy, METH_NOARGS, MD5_copy__doc__},
	{"digest", (PyCFunction)MD5_digest, METH_NOARGS, MD5_digest__doc__},
	{"hexdigest", (PyCFunction)MD5_hexdigest, METH_NOARGS, MD5_hexdigest__doc__},
	{"update", (PyCFunction)MD5_update, METH_VARARGS, MD5_update__doc__},
	{NULL, NULL} /* sentinel */
	};

	static PyObject *
	MD5_get_block_size(PyObject self, void closure)
	{
	return PyLong_FromLong(MD5_BLOCKSIZE);
	}

	static PyObject *
	MD5_get_name(PyObject self, void closure)
	{
	return PyUnicode_FromStringAndSize("MD5", 3);
	}

	static PyObject *
	md5_get_digest_size(PyObject self, void closure)
	{
	return PyLong_FromLong(MD5_DIGESTSIZE);
	}


	static PyGetSetDef MD5_getseters[] = {
	{"block_size",
	(getter)MD5_get_block_size, NULL,
	NULL,
	NULL},
	{"name",
	(getter)MD5_get_name, NULL,
	NULL,
	NULL},
	{"digest_size",
	(getter)md5_get_digest_size, NULL,
	NULL,
	NULL},
	{NULL} /* Sentinel */
	};

	static PyTypeObject MD5type = {
	PyVarObject_HEAD_INIT(NULL, 0)
	"_md5.md5", /tp_name/
	sizeof(MD5object), /tp_size/
	0, /tp_itemsize/
	/* methods */
	MD5_dealloc, /tp_dealloc/
	0, /tp_print/
	0, /tp_getattr/
	0, /tp_setattr/
	0, /tp_reserved/
	0, /tp_repr/
	0, /tp_as_number/
	0, /tp_as_sequence/
	0, /tp_as_mapping/
	0, /tp_hash/
	0, /tp_call/
	0, /tp_str/
	0, /tp_getattro/
	0, /tp_setattro/
	0, /tp_as_buffer/
	Py_TPFLAGS_DEFAULT, /tp_flags/
	0, /tp_doc/
	0, /tp_traverse/
	0, /tp_clear/
	0, /tp_richcompare/
	0, /tp_weaklistoffset/
	0, /tp_iter/
	0, /tp_iternext/
	MD5_methods, /* tp_methods */
	NULL, /* tp_members */
	MD5_getseters, /* tp_getset */
	};


	/* The single module-level function: new() */

	PyDoc_STRVAR(MD5_new__doc__,
	"Return a new MD5 hash object; optionally initialized with a string.");

	static PyObject *
	MD5_new(PyObject self, PyObject args, PyObject *kwdict)
	{
	static char *kwlist[] = {"string", NULL};
	MD5object *new;
	PyObject *data_obj = NULL;
	Py_buffer buf;

	if (!PyArg_ParseTupleAndKeywords(args, kwdict, "\|O:new", kwlist,
	&data_obj)) {
	return NULL;
	}

	if (data_obj)
	GET_BUFFER_VIEW_OR_ERROUT(data_obj, &buf);

	if ((new = newMD5object()) == NULL) {
	if (data_obj)
	PyBuffer_Release(&buf);
	return NULL;
	}

	md5_init(&new->hash_state);

	if (PyErr_Occurred()) {
	Py_DECREF(new);
	if (data_obj)
	PyBuffer_Release(&buf);
	return NULL;
	}
	if (data_obj) {
	md5_process(&new->hash_state, buf.buf, buf.len);
	PyBuffer_Release(&buf);
	}

	return (PyObject *)new;
	}


	/* List of functions exported by this module */

	static struct PyMethodDef MD5_functions[] = {
	{"md5", (PyCFunction)MD5_new, METH_VARARGS\|METH_KEYWORDS, MD5_new__doc__},
	{NULL, NULL} /* Sentinel */
	};


	/* Initialize this module. */

	#define insint(n,v) { PyModule_AddIntConstant(m,n,v); }


	static struct PyModuleDef _md5module = {
	PyModuleDef_HEAD_INIT,
	"_md5",
	NULL,
	-1,
	MD5_functions,
	NULL,
	NULL,
	NULL,
	NULL
	};

	PyMODINIT_FUNC
	PyInit__md5(void)
	{
	Py_TYPE(&MD5type) = &PyType_Type;
	if (PyType_Ready(&MD5type) < 0)
	return NULL;
	return PyModule_Create(&_md5module);
	}