shamodule.c

python s60 1.4.5版本的源代码

sha_final(unsigned char digest[20], SHAobject *sha_info)
{
    int count;
    SHA_INT32 lo_bit_count, hi_bit_count;

    lo_bit_count = sha_info->count_lo;
    hi_bit_count = sha_info->count_hi;
    count = (int) ((lo_bit_count >> 3) & 0x3f);
    ((SHA_BYTE *) sha_info->data)[count++] = 0x80;
    if (count > SHA_BLOCKSIZE - 8) {
	memset(((SHA_BYTE *) sha_info->data) + count, 0,
	       SHA_BLOCKSIZE - count);
	sha_transform(sha_info);
	memset((SHA_BYTE *) sha_info->data, 0, SHA_BLOCKSIZE - 8);
    }
    else {
	memset(((SHA_BYTE *) sha_info->data) + count, 0,
	       SHA_BLOCKSIZE - 8 - count);
    }

    /* GJS: note that we add the hi/lo in big-endian. sha_transform will
       swap these values into host-order. */
    sha_info->data[56] = (hi_bit_count >> 24) & 0xff;
    sha_info->data[57] = (hi_bit_count >> 16) & 0xff;
    sha_info->data[58] = (hi_bit_count >>  8) & 0xff;
    sha_info->data[59] = (hi_bit_count >>  0) & 0xff;
    sha_info->data[60] = (lo_bit_count >> 24) & 0xff;
    sha_info->data[61] = (lo_bit_count >> 16) & 0xff;
    sha_info->data[62] = (lo_bit_count >>  8) & 0xff;
    sha_info->data[63] = (lo_bit_count >>  0) & 0xff;
    sha_transform(sha_info);
    digest[ 0] = (unsigned char) ((sha_info->digest[0] >> 24) & 0xff);
    digest[ 1] = (unsigned char) ((sha_info->digest[0] >> 16) & 0xff);
    digest[ 2] = (unsigned char) ((sha_info->digest[0] >>  8) & 0xff);
    digest[ 3] = (unsigned char) ((sha_info->digest[0]      ) & 0xff);
    digest[ 4] = (unsigned char) ((sha_info->digest[1] >> 24) & 0xff);
    digest[ 5] = (unsigned char) ((sha_info->digest[1] >> 16) & 0xff);
    digest[ 6] = (unsigned char) ((sha_info->digest[1] >>  8) & 0xff);
    digest[ 7] = (unsigned char) ((sha_info->digest[1]      ) & 0xff);
    digest[ 8] = (unsigned char) ((sha_info->digest[2] >> 24) & 0xff);
    digest[ 9] = (unsigned char) ((sha_info->digest[2] >> 16) & 0xff);
    digest[10] = (unsigned char) ((sha_info->digest[2] >>  8) & 0xff);
    digest[11] = (unsigned char) ((sha_info->digest[2]      ) & 0xff);
    digest[12] = (unsigned char) ((sha_info->digest[3] >> 24) & 0xff);
    digest[13] = (unsigned char) ((sha_info->digest[3] >> 16) & 0xff);
    digest[14] = (unsigned char) ((sha_info->digest[3] >>  8) & 0xff);
    digest[15] = (unsigned char) ((sha_info->digest[3]      ) & 0xff);
    digest[16] = (unsigned char) ((sha_info->digest[4] >> 24) & 0xff);
    digest[17] = (unsigned char) ((sha_info->digest[4] >> 16) & 0xff);
    digest[18] = (unsigned char) ((sha_info->digest[4] >>  8) & 0xff);
    digest[19] = (unsigned char) ((sha_info->digest[4]      ) & 0xff);
}

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

staticforward PyTypeObject SHAtype;


static SHAobject *
newSHAobject(void)
{
    return (SHAobject *)PyObject_New(SHAobject, &SHAtype);
}

/* Internal methods for a hashing object */

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


/* External methods for a hashing object */

static char SHA_copy__doc__[] = 
"Return a copy of the hashing object.";

static PyObject *
SHA_copy(SHAobject *self, PyObject *args)
{
    SHAobject *newobj;

    if (!PyArg_ParseTuple(args, ":copy")) {
        return NULL;
    }
    if ( (newobj = newSHAobject())==NULL)
        return NULL;

    SHAcopy(self, newobj);
    return (PyObject *)newobj;
}

static char SHA_digest__doc__[] = 
"Return the digest value as a string of binary data.";

static PyObject *
SHA_digest(SHAobject *self, PyObject *args)
{
    unsigned char digest[SHA_DIGESTSIZE];
    SHAobject temp;

    if (!PyArg_ParseTuple(args, ":digest"))
        return NULL;

    SHAcopy(self, &temp);
    sha_final(digest, &temp);
    return PyString_FromStringAndSize((const char *)digest, sizeof(digest));
}

static char SHA_hexdigest__doc__[] = 
"Return the digest value as a string of hexadecimal digits.";

static PyObject *
SHA_hexdigest(SHAobject *self, PyObject *args)
{
    unsigned char digest[SHA_DIGESTSIZE];
    SHAobject temp;
    PyObject *retval;
    char *hex_digest;
    int i, j;

    if (!PyArg_ParseTuple(args, ":hexdigest"))
        return NULL;

    /* Get the raw (binary) digest value */
    SHAcopy(self, &temp);
    sha_final(digest, &temp);

    /* Create a new string */
    retval = PyString_FromStringAndSize(NULL, sizeof(digest) * 2);
    if (!retval)
	    return NULL;
    hex_digest = PyString_AsString(retval);
    if (!hex_digest) {
	    Py_DECREF(retval);
	    return NULL;
    }

    /* Make hex version of the digest */
    for(i=j=0; i<sizeof(digest); 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;
}

static char SHA_update__doc__[] = 
"Update this hashing object's state with the provided string.";

static PyObject *
SHA_update(SHAobject *self, PyObject *args)
{
    unsigned char *cp;
    int len;

    if (!PyArg_ParseTuple(args, "s#:update", &cp, &len))
        return NULL;

    sha_update(self, cp, len);

    Py_INCREF(Py_None);
    return Py_None;
}

static PyMethodDef SHA_methods[] = {
    {"copy",	  (PyCFunction)SHA_copy,      METH_VARARGS, SHA_copy__doc__},
    {"digest",	  (PyCFunction)SHA_digest,    METH_VARARGS, SHA_digest__doc__},
    {"hexdigest", (PyCFunction)SHA_hexdigest, METH_VARARGS, SHA_hexdigest__doc__},
    {"update",	  (PyCFunction)SHA_update,    METH_VARARGS, SHA_update__doc__},
    {NULL,	  NULL}		/* sentinel */
};

static PyObject *
SHA_getattr(PyObject *self, char *name)
{
    if (strcmp(name, "blocksize")==0)
        return PyInt_FromLong(1);
    if (strcmp(name, "digest_size")==0 || strcmp(name, "digestsize")==0)
        return PyInt_FromLong(20);

    return Py_FindMethod(SHA_methods, self, name);
}

static PyTypeObject SHAtype = {
    PyObject_HEAD_INIT(NULL)
    0,			/*ob_size*/
    "sha.SHA",		/*tp_name*/
    sizeof(SHAobject),	/*tp_size*/
    0,			/*tp_itemsize*/
    /* methods */
    SHA_dealloc,	/*tp_dealloc*/
    0,			/*tp_print*/
    SHA_getattr,	/*tp_getattr*/
};


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

static char SHA_new__doc__[] =
 "Return a new SHA hashing object.  An optional string "
 "argument may be provided; if present, this string will be "
 " automatically hashed."; 

static PyObject *
SHA_new(PyObject *self, PyObject *args, PyObject *kwdict)
{
    static char *kwlist[] = {"string", NULL};
    SHAobject *new;
    unsigned char *cp = NULL;
    int len;

    if (!PyArg_ParseTupleAndKeywords(args, kwdict, "|s#:new", kwlist,
                                     &cp, &len)) {
        return NULL;
    }

    if ((new = newSHAobject()) == NULL)
        return NULL;

    sha_init(new);

    if (PyErr_Occurred()) {
        Py_DECREF(new);
        return NULL;
    }
    if (cp)
        sha_update(new, cp, len);

    return (PyObject *)new;
}


/* List of functions exported by this module */

static struct PyMethodDef SHA_functions[] = {
    {"new", (PyCFunction)SHA_new, METH_VARARGS|METH_KEYWORDS, SHA_new__doc__},
    {"sha", (PyCFunction)SHA_new, METH_VARARGS|METH_KEYWORDS, SHA_new__doc__},
    {NULL,	NULL}		 /* Sentinel */
};


/* Initialize this module. */

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

DL_EXPORT(void)
initsha(void)
{
    PyObject *d, *m;

    SHAtype.ob_type = &PyType_Type;
    m = Py_InitModule("sha", SHA_functions);

    /* Add some symbolic constants to the module */
    d = PyModule_GetDict(m);
    insint("blocksize", 1);  /* For future use, in case some hash
                                functions require an integral number of
                                blocks */ 
    insint("digestsize", 20);
    insint("digest_size", 20);
}