1
2/* MD5 module */
3
4/* This module provides an interface to the RSA Data Security,
5   Inc. MD5 Message-Digest Algorithm, described in RFC 1321.
6   It requires the files md5c.c and md5.h (which are slightly changed
7   from the versions in the RFC to avoid the "global.h" file.) */
8
9
10/* MD5 objects */
11
12#include "Python.h"
13#include "structmember.h"
14#include "md5.h"
15
16typedef struct {
17    PyObject_HEAD
18    md5_state_t         md5;            /* the context holder */
19} md5object;
20
21static PyTypeObject MD5type;
22
23#define is_md5object(v)         ((v)->ob_type == &MD5type)
24
25static md5object *
26newmd5object(void)
27{
28    md5object *md5p;
29
30    md5p = PyObject_New(md5object, &MD5type);
31    if (md5p == NULL)
32        return NULL;
33
34    md5_init(&md5p->md5);       /* actual initialisation */
35    return md5p;
36}
37
38
39/* MD5 methods */
40
41static void
42md5_dealloc(md5object *md5p)
43{
44    PyObject_Del(md5p);
45}
46
47
48/* MD5 methods-as-attributes */
49
50static PyObject *
51md5_update(md5object *self, PyObject *args)
52{
53    Py_buffer view;
54
55    if (!PyArg_ParseTuple(args, "s*:update", &view))
56        return NULL;
57
58    md5_append(&self->md5, (unsigned char*)view.buf,
59               Py_SAFE_DOWNCAST(view.len, Py_ssize_t, unsigned int));
60
61    PyBuffer_Release(&view);
62    Py_RETURN_NONE;
63}
64
65PyDoc_STRVAR(update_doc,
66"update (arg)\n\
67\n\
68Update the md5 object with the string arg. Repeated calls are\n\
69equivalent to a single call with the concatenation of all the\n\
70arguments.");
71
72
73static PyObject *
74md5_digest(md5object *self)
75{
76    md5_state_t mdContext;
77    unsigned char aDigest[16];
78
79    /* make a temporary copy, and perform the final */
80    mdContext = self->md5;
81    md5_finish(&mdContext, aDigest);
82
83    return PyString_FromStringAndSize((char *)aDigest, 16);
84}
85
86PyDoc_STRVAR(digest_doc,
87"digest() -> string\n\
88\n\
89Return the digest of the strings passed to the update() method so\n\
90far. This is a 16-byte string which may contain non-ASCII characters,\n\
91including null bytes.");
92
93
94static PyObject *
95md5_hexdigest(md5object *self)
96{
97    md5_state_t mdContext;
98    unsigned char digest[16];
99    unsigned char hexdigest[32];
100    int i, j;
101
102    /* make a temporary copy, and perform the final */
103    mdContext = self->md5;
104    md5_finish(&mdContext, digest);
105
106    /* Make hex version of the digest */
107    for(i=j=0; i<16; i++) {
108        char c;
109        c = (digest[i] >> 4) & 0xf;
110        c = (c>9) ? c+'a'-10 : c + '0';
111        hexdigest[j++] = c;
112        c = (digest[i] & 0xf);
113        c = (c>9) ? c+'a'-10 : c + '0';
114        hexdigest[j++] = c;
115    }
116    return PyString_FromStringAndSize((char*)hexdigest, 32);
117}
118
119
120PyDoc_STRVAR(hexdigest_doc,
121"hexdigest() -> string\n\
122\n\
123Like digest(), but returns the digest as a string of hexadecimal digits.");
124
125
126static PyObject *
127md5_copy(md5object *self)
128{
129    md5object *md5p;
130
131    if ((md5p = newmd5object()) == NULL)
132        return NULL;
133
134    md5p->md5 = self->md5;
135
136    return (PyObject *)md5p;
137}
138
139PyDoc_STRVAR(copy_doc,
140"copy() -> md5 object\n\
141\n\
142Return a copy (``clone'') of the md5 object.");
143
144
145static PyMethodDef md5_methods[] = {
146    {"update",    (PyCFunction)md5_update,    METH_VARARGS, update_doc},
147    {"digest",    (PyCFunction)md5_digest,    METH_NOARGS,  digest_doc},
148    {"hexdigest", (PyCFunction)md5_hexdigest, METH_NOARGS,  hexdigest_doc},
149    {"copy",      (PyCFunction)md5_copy,      METH_NOARGS,  copy_doc},
150    {NULL, NULL}                             /* sentinel */
151};
152
153static PyObject *
154md5_get_block_size(PyObject *self, void *closure)
155{
156    return PyInt_FromLong(64);
157}
158
159static PyObject *
160md5_get_digest_size(PyObject *self, void *closure)
161{
162    return PyInt_FromLong(16);
163}
164
165static PyObject *
166md5_get_name(PyObject *self, void *closure)
167{
168    return PyString_FromStringAndSize("MD5", 3);
169}
170
171static PyGetSetDef md5_getseters[] = {
172    {"digest_size",
173     (getter)md5_get_digest_size, NULL,
174     NULL,
175     NULL},
176    {"block_size",
177     (getter)md5_get_block_size, NULL,
178     NULL,
179     NULL},
180    {"name",
181     (getter)md5_get_name, NULL,
182     NULL,
183     NULL},
184    /* the old md5 and sha modules support 'digest_size' as in PEP 247.
185     * the old sha module also supported 'digestsize'.  ugh. */
186    {"digestsize",
187     (getter)md5_get_digest_size, NULL,
188     NULL,
189     NULL},
190    {NULL}  /* Sentinel */
191};
192
193
194PyDoc_STRVAR(module_doc,
195"This module implements the interface to RSA's MD5 message digest\n\
196algorithm (see also Internet RFC 1321). Its use is quite\n\
197straightforward: use the new() to create an md5 object. You can now\n\
198feed this object with arbitrary strings using the update() method, and\n\
199at any point you can ask it for the digest (a strong kind of 128-bit\n\
200checksum, a.k.a. ``fingerprint'') of the concatenation of the strings\n\
201fed to it so far using the digest() method.\n\
202\n\
203Functions:\n\
204\n\
205new([arg]) -- return a new md5 object, initialized with arg if provided\n\
206md5([arg]) -- DEPRECATED, same as new, but for compatibility\n\
207\n\
208Special Objects:\n\
209\n\
210MD5Type -- type object for md5 objects");
211
212PyDoc_STRVAR(md5type_doc,
213"An md5 represents the object used to calculate the MD5 checksum of a\n\
214string of information.\n\
215\n\
216Methods:\n\
217\n\
218update() -- updates the current digest with an additional string\n\
219digest() -- return the current digest value\n\
220hexdigest() -- return the current digest as a string of hexadecimal digits\n\
221copy() -- return a copy of the current md5 object");
222
223static PyTypeObject MD5type = {
224    PyVarObject_HEAD_INIT(NULL, 0)
225    "_md5.md5",                   /*tp_name*/
226    sizeof(md5object),            /*tp_size*/
227    0,                            /*tp_itemsize*/
228    /* methods */
229    (destructor)md5_dealloc,  /*tp_dealloc*/
230    0,                            /*tp_print*/
231    0,                        /*tp_getattr*/
232    0,                            /*tp_setattr*/
233    0,                            /*tp_compare*/
234    0,                            /*tp_repr*/
235    0,                            /*tp_as_number*/
236    0,                        /*tp_as_sequence*/
237    0,                            /*tp_as_mapping*/
238    0,                            /*tp_hash*/
239    0,                            /*tp_call*/
240    0,                            /*tp_str*/
241    0,                            /*tp_getattro*/
242    0,                            /*tp_setattro*/
243    0,                            /*tp_as_buffer*/
244    Py_TPFLAGS_DEFAULT,           /*tp_flags*/
245    md5type_doc,                  /*tp_doc*/
246    0,                        /*tp_traverse*/
247    0,                            /*tp_clear*/
248    0,                            /*tp_richcompare*/
249    0,                            /*tp_weaklistoffset*/
250    0,                            /*tp_iter*/
251    0,                            /*tp_iternext*/
252    md5_methods,                  /*tp_methods*/
253    0,                            /*tp_members*/
254    md5_getseters,            /*tp_getset*/
255};
256
257
258/* MD5 functions */
259
260static PyObject *
261MD5_new(PyObject *self, PyObject *args)
262{
263    md5object *md5p;
264    Py_buffer view = { 0 };
265
266    if (!PyArg_ParseTuple(args, "|s*:new", &view))
267        return NULL;
268
269    if ((md5p = newmd5object()) == NULL) {
270        PyBuffer_Release(&view);
271        return NULL;
272    }
273
274    if (view.len > 0) {
275        md5_append(&md5p->md5, (unsigned char*)view.buf,
276               Py_SAFE_DOWNCAST(view.len, Py_ssize_t, unsigned int));
277    }
278    PyBuffer_Release(&view);
279
280    return (PyObject *)md5p;
281}
282
283PyDoc_STRVAR(new_doc,
284"new([arg]) -> md5 object\n\
285\n\
286Return a new md5 object. If arg is present, the method call update(arg)\n\
287is made.");
288
289
290/* List of functions exported by this module */
291
292static PyMethodDef md5_functions[] = {
293    {"new",             (PyCFunction)MD5_new, METH_VARARGS, new_doc},
294    {NULL,              NULL}   /* Sentinel */
295};
296
297
298/* Initialize this module. */
299
300PyMODINIT_FUNC
301init_md5(void)
302{
303    PyObject *m, *d;
304
305    Py_TYPE(&MD5type) = &PyType_Type;
306    if (PyType_Ready(&MD5type) < 0)
307        return;
308    m = Py_InitModule3("_md5", md5_functions, module_doc);
309    if (m == NULL)
310        return;
311    d = PyModule_GetDict(m);
312    PyDict_SetItemString(d, "MD5Type", (PyObject *)&MD5type);
313    PyModule_AddIntConstant(m, "digest_size", 16);
314    /* No need to check the error here, the caller will do that */
315}
316