Modules/md5module.c

   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
  16 typedef struct {
  17         PyObject_HEAD
  18         md5_state_t     md5;            /* the context holder */
  19 } md5object;
  20
  21 static PyTypeObject MD5type;
  22
  23 #define is_md5object(v)         ((v)->ob_type == &MD5type)
  24
  25 static md5object *
  26 newmd5object(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
  41 static void
  42 md5_dealloc(md5object *md5p)
  43 {
  44         PyObject_Del(md5p);
  45 }
  46
  47
  48 /* MD5 methods-as-attributes */
  49
  50 static PyObject *
  51 md5_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
  65 PyDoc_STRVAR(update_doc,
  66 "update (arg)\n\
  67 \n\
  68 Update the md5 object with the string arg. Repeated calls are\n\
  69 equivalent to a single call with the concatenation of all the\n\
  70 arguments.");
  71
  72
  73 static PyObject *
  74 md5_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
  86 PyDoc_STRVAR(digest_doc,
  87 "digest() -> string\n\
  88 \n\
  89 Return the digest of the strings passed to the update() method so\n\
  90 far. This is a 16-byte string which may contain non-ASCII characters,\n\
  91 including null bytes.");
  92
  93
  94 static PyObject *
  95 md5_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
 120 PyDoc_STRVAR(hexdigest_doc,
 121 "hexdigest() -> string\n\
 122 \n\
 123 Like digest(), but returns the digest as a string of hexadecimal digits.");
 124
 125
 126 static PyObject *
 127 md5_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
 139 PyDoc_STRVAR(copy_doc,
 140 "copy() -> md5 object\n\
 141 \n\
 142 Return a copy (``clone'') of the md5 object.");
 143
 144
 145 static 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
 153 static PyObject *
 154 md5_get_block_size(PyObject *self, void *closure)
 155 {
 156     return PyInt_FromLong(64);
 157 }
 158
 159 static PyObject *
 160 md5_get_digest_size(PyObject *self, void *closure)
 161 {
 162     return PyInt_FromLong(16);
 163 }
 164
 165 static PyObject *
 166 md5_get_name(PyObject *self, void *closure)
 167 {
 168     return PyString_FromStringAndSize("MD5", 3);
 169 }
 170
 171 static 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
 194 PyDoc_STRVAR(module_doc,
 195 "This module implements the interface to RSA's MD5 message digest\n\
 196 algorithm (see also Internet RFC 1321). Its use is quite\n\
 197 straightforward: use the new() to create an md5 object. You can now\n\
 198 feed this object with arbitrary strings using the update() method, and\n\
 199 at any point you can ask it for the digest (a strong kind of 128-bit\n\
 200 checksum, a.k.a. ``fingerprint'') of the concatenation of the strings\n\
 201 fed to it so far using the digest() method.\n\
 202 \n\
 203 Functions:\n\
 204 \n\
 205 new([arg]) -- return a new md5 object, initialized with arg if provided\n\
 206 md5([arg]) -- DEPRECATED, same as new, but for compatibility\n\
 207 \n\
 208 Special Objects:\n\
 209 \n\
 210 MD5Type -- type object for md5 objects");
 211
 212 PyDoc_STRVAR(md5type_doc,
 213 "An md5 represents the object used to calculate the MD5 checksum of a\n\
 214 string of information.\n\
 215 \n\
 216 Methods:\n\
 217 \n\
 218 update() -- updates the current digest with an additional string\n\
 219 digest() -- return the current digest value\n\
 220 hexdigest() -- return the current digest as a string of hexadecimal digits\n\
 221 copy() -- return a copy of the current md5 object");
 222
 223 static 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
 260 static PyObject *
 261 MD5_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
 283 PyDoc_STRVAR(new_doc,
 284 "new([arg]) -> md5 object\n\
 285 \n\
 286 Return a new md5 object. If arg is present, the method call update(arg)\n\
 287 is made.");
 288
 289
 290 /* List of functions exported by this module */
 291
 292 static PyMethodDef md5_functions[] = {
 293         {"new",         (PyCFunction)MD5_new, METH_VARARGS, new_doc},
 294         {NULL,          NULL}   /* Sentinel */
 295 };
 296
 297
 298 /* Initialize this module. */
 299
 300 PyMODINIT_FUNC
 301 init_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 }