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 #include "hashlib.h"
  16
  17 typedef struct {
  18         PyObject_HEAD
  19         md5_state_t     md5;            /* the context holder */
  20 } md5object;
  21
  22 static PyTypeObject MD5type;
  23
  24 #define is_md5object(v)         ((v)->ob_type == &MD5type)
  25
  26 static md5object *
  27 newmd5object(void)
  28 {
  29         md5object *md5p;
  30
  31         md5p = PyObject_New(md5object, &MD5type);
  32         if (md5p == NULL)
  33                 return NULL;
  34
  35         md5_init(&md5p->md5);   /* actual initialisation */
  36         return md5p;
  37 }
  38
  39
  40 /* MD5 methods */
  41
  42 static void
  43 md5_dealloc(md5object *md5p)
  44 {
  45         PyObject_Del(md5p);
  46 }
  47
  48
  49 /* MD5 methods-as-attributes */
  50
  51 static PyObject *
  52 md5_update(md5object *self, PyObject *args)
  53 {
  54         PyObject *data_obj;
  55         Py_buffer view;
  56
  57         if (!PyArg_ParseTuple(args, "O:update", &data_obj))
  58                 return NULL;
  59
  60         GET_BUFFER_VIEW_OR_ERROUT(data_obj, &view, NULL);
  61
  62         md5_append(&self->md5, (unsigned char*)view.buf,
  63                    Py_SAFE_DOWNCAST(view.len, Py_ssize_t, unsigned int));
  64
  65         PyBuffer_Release(&view);
  66         Py_INCREF(Py_None);
  67         return Py_None;
  68 }
  69
  70 PyDoc_STRVAR(update_doc,
  71 "update (arg)\n\
  72 \n\
  73 Update the md5 object with the string arg. Repeated calls are\n\
  74 equivalent to a single call with the concatenation of all the\n\
  75 arguments.");
  76
  77
  78 static PyObject *
  79 md5_digest(md5object *self)
  80 {
  81         md5_state_t mdContext;
  82         unsigned char aDigest[16];
  83
  84         /* make a temporary copy, and perform the final */
  85         mdContext = self->md5;
  86         md5_finish(&mdContext, aDigest);
  87
  88         return PyString_FromStringAndSize((char *)aDigest, 16);
  89 }
  90
  91 PyDoc_STRVAR(digest_doc,
  92 "digest() -> string\n\
  93 \n\
  94 Return the digest of the strings passed to the update() method so\n\
  95 far. This is a 16-byte string which may contain non-ASCII characters,\n\
  96 including null bytes.");
  97
  98
  99 static PyObject *
 100 md5_hexdigest(md5object *self)
 101 {
 102         md5_state_t mdContext;
 103         unsigned char digest[16];
 104         unsigned char hexdigest[32];
 105         int i, j;
 106
 107         /* make a temporary copy, and perform the final */
 108         mdContext = self->md5;
 109         md5_finish(&mdContext, digest);
 110
 111         /* Make hex version of the digest */
 112         for(i=j=0; i<16; i++) {
 113                 char c;
 114                 c = (digest[i] >> 4) & 0xf;
 115                 c = (c>9) ? c+'a'-10 : c + '0';
 116                 hexdigest[j++] = c;
 117                 c = (digest[i] & 0xf);
 118                 c = (c>9) ? c+'a'-10 : c + '0';
 119                 hexdigest[j++] = c;
 120         }
 121         return PyString_FromStringAndSize((char*)hexdigest, 32);
 122 }
 123
 124
 125 PyDoc_STRVAR(hexdigest_doc,
 126 "hexdigest() -> string\n\
 127 \n\
 128 Like digest(), but returns the digest as a string of hexadecimal digits.");
 129
 130
 131 static PyObject *
 132 md5_copy(md5object *self)
 133 {
 134         md5object *md5p;
 135
 136         if ((md5p = newmd5object()) == NULL)
 137                 return NULL;
 138
 139         md5p->md5 = self->md5;
 140
 141         return (PyObject *)md5p;
 142 }
 143
 144 PyDoc_STRVAR(copy_doc,
 145 "copy() -> md5 object\n\
 146 \n\
 147 Return a copy (``clone'') of the md5 object.");
 148
 149
 150 static PyMethodDef md5_methods[] = {
 151         {"update",    (PyCFunction)md5_update,    METH_VARARGS, update_doc},
 152         {"digest",    (PyCFunction)md5_digest,    METH_NOARGS,  digest_doc},
 153         {"hexdigest", (PyCFunction)md5_hexdigest, METH_NOARGS,  hexdigest_doc},
 154         {"copy",      (PyCFunction)md5_copy,      METH_NOARGS,  copy_doc},
 155         {NULL, NULL}                         /* sentinel */
 156 };
 157
 158 static PyObject *
 159 md5_get_block_size(PyObject *self, void *closure)
 160 {
 161     return PyInt_FromLong(64);
 162 }
 163
 164 static PyObject *
 165 md5_get_digest_size(PyObject *self, void *closure)
 166 {
 167     return PyInt_FromLong(16);
 168 }
 169
 170 static PyObject *
 171 md5_get_name(PyObject *self, void *closure)
 172 {
 173     return PyString_FromStringAndSize("MD5", 3);
 174 }
 175
 176 static PyGetSetDef md5_getseters[] = {
 177     {"digest_size",
 178      (getter)md5_get_digest_size, NULL,
 179      NULL,
 180      NULL},
 181     {"block_size",
 182      (getter)md5_get_block_size, NULL,
 183      NULL,
 184      NULL},
 185     {"name",
 186      (getter)md5_get_name, NULL,
 187      NULL,
 188      NULL},
 189     /* the old md5 and sha modules support 'digest_size' as in PEP 247.
 190      * the old sha module also supported 'digestsize'.  ugh. */
 191     {"digestsize",
 192      (getter)md5_get_digest_size, NULL,
 193      NULL,
 194      NULL},
 195     {NULL}  /* Sentinel */
 196 };
 197
 198
 199 PyDoc_STRVAR(module_doc,
 200 "This module implements the interface to RSA's MD5 message digest\n\
 201 algorithm (see also Internet RFC 1321). Its use is quite\n\
 202 straightforward: use the new() to create an md5 object. You can now\n\
 203 feed this object with arbitrary strings using the update() method, and\n\
 204 at any point you can ask it for the digest (a strong kind of 128-bit\n\
 205 checksum, a.k.a. ``fingerprint'') of the concatenation of the strings\n\
 206 fed to it so far using the digest() method.\n\
 207 \n\
 208 Functions:\n\
 209 \n\
 210 new([arg]) -- return a new md5 object, initialized with arg if provided\n\
 211 md5([arg]) -- DEPRECATED, same as new, but for compatibility\n\
 212 \n\
 213 Special Objects:\n\
 214 \n\
 215 MD5Type -- type object for md5 objects");
 216
 217 PyDoc_STRVAR(md5type_doc,
 218 "An md5 represents the object used to calculate the MD5 checksum of a\n\
 219 string of information.\n\
 220 \n\
 221 Methods:\n\
 222 \n\
 223 update() -- updates the current digest with an additional string\n\
 224 digest() -- return the current digest value\n\
 225 hexdigest() -- return the current digest as a string of hexadecimal digits\n\
 226 copy() -- return a copy of the current md5 object");
 227
 228 static PyTypeObject MD5type = {
 229         PyVarObject_HEAD_INIT(NULL, 0)
 230         "_md5.md5",               /*tp_name*/
 231         sizeof(md5object),        /*tp_size*/
 232         0,                        /*tp_itemsize*/
 233         /* methods */
 234         (destructor)md5_dealloc,  /*tp_dealloc*/
 235         0,                        /*tp_print*/
 236         0,                        /*tp_getattr*/
 237         0,                        /*tp_setattr*/
 238         0,                        /*tp_compare*/
 239         0,                        /*tp_repr*/
 240         0,                        /*tp_as_number*/
 241         0,                        /*tp_as_sequence*/
 242         0,                        /*tp_as_mapping*/
 243         0,                        /*tp_hash*/
 244         0,                        /*tp_call*/
 245         0,                        /*tp_str*/
 246         0,                        /*tp_getattro*/
 247         0,                        /*tp_setattro*/
 248         0,                        /*tp_as_buffer*/
 249         Py_TPFLAGS_DEFAULT,       /*tp_flags*/
 250         md5type_doc,              /*tp_doc*/
 251         0,                        /*tp_traverse*/
 252         0,                        /*tp_clear*/
 253         0,                        /*tp_richcompare*/
 254         0,                        /*tp_weaklistoffset*/
 255         0,                        /*tp_iter*/
 256         0,                        /*tp_iternext*/
 257         md5_methods,              /*tp_methods*/
 258         0,                        /*tp_members*/
 259         md5_getseters,            /*tp_getset*/
 260 };
 261
 262
 263 /* MD5 functions */
 264
 265 static PyObject *
 266 MD5_new(PyObject *self, PyObject *args)
 267 {
 268         md5object *md5p;
 269         PyObject *data_obj = NULL;
 270         Py_buffer view;
 271
 272         if (!PyArg_ParseTuple(args, "|O:new", &data_obj))
 273                 return NULL;
 274
 275         if (data_obj)
 276                 GET_BUFFER_VIEW_OR_ERROUT(data_obj, &view, NULL);
 277
 278         if ((md5p = newmd5object()) == NULL) {
 279                 if (data_obj)
 280                         PyBuffer_Release(&view);
 281                 return NULL;
 282         }
 283
 284         if (data_obj) {
 285                 md5_append(&md5p->md5, (unsigned char*)view.buf,
 286                        Py_SAFE_DOWNCAST(view.len, Py_ssize_t, unsigned int));
 287                 PyBuffer_Release(&view);
 288         }
 289
 290         return (PyObject *)md5p;
 291 }
 292
 293 PyDoc_STRVAR(new_doc,
 294 "new([arg]) -> md5 object\n\
 295 \n\
 296 Return a new md5 object. If arg is present, the method call update(arg)\n\
 297 is made.");
 298
 299
 300 /* List of functions exported by this module */
 301
 302 static PyMethodDef md5_functions[] = {
 303         {"new",         (PyCFunction)MD5_new, METH_VARARGS, new_doc},
 304         {NULL,          NULL}   /* Sentinel */
 305 };
 306
 307
 308 /* Initialize this module. */
 309
 310 PyMODINIT_FUNC
 311 init_md5(void)
 312 {
 313         PyObject *m, *d;
 314
 315         Py_TYPE(&MD5type) = &PyType_Type;
 316         if (PyType_Ready(&MD5type) < 0)
 317             return;
 318         m = Py_InitModule3("_md5", md5_functions, module_doc);
 319         if (m == NULL)
 320             return;
 321         d = PyModule_GetDict(m);
 322         PyDict_SetItemString(d, "MD5Type", (PyObject *)&MD5type);
 323         PyModule_AddIntConstant(m, "digest_size", 16);
 324         /* No need to check the error here, the caller will do that */
 325 }