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 "md5.h"
  14
  15 typedef struct {
  16         PyObject_HEAD
  17         MD5_CTX md5;            /* the context holder */
  18 } md5object;
  19
  20 static PyTypeObject MD5type;
  21
  22 #define is_md5object(v)         ((v)->ob_type == &MD5type)
  23
  24 static md5object *
  25 newmd5object(void)
  26 {
  27         md5object *md5p;
  28
  29         md5p = PyObject_New(md5object, &MD5type);
  30         if (md5p == NULL)
  31                 return NULL;
  32
  33         MD5Init(&md5p->md5);    /* actual initialisation */
  34         return md5p;
  35 }
  36
  37
  38 /* MD5 methods */
  39
  40 static void
  41 md5_dealloc(md5object *md5p)
  42 {
  43         PyObject_Del(md5p);
  44 }
  45
  46
  47 /* MD5 methods-as-attributes */
  48
  49 static PyObject *
  50 md5_update(md5object *self, PyObject *args)
  51 {
  52         unsigned char *cp;
  53         int len;
  54
  55         if (!PyArg_ParseTuple(args, "s#:update", &cp, &len))
  56                 return NULL;
  57
  58         MD5Update(&self->md5, cp, len);
  59
  60         Py_INCREF(Py_None);
  61         return Py_None;
  62 }
  63
  64 PyDoc_STRVAR(update_doc,
  65 "update (arg)\n\
  66 \n\
  67 Update the md5 object with the string arg. Repeated calls are\n\
  68 equivalent to a single call with the concatenation of all the\n\
  69 arguments.");
  70
  71
  72 static PyObject *
  73 md5_digest(md5object *self)
  74 {
  75         MD5_CTX mdContext;
  76         unsigned char aDigest[16];
  77
  78         /* make a temporary copy, and perform the final */
  79         mdContext = self->md5;
  80         MD5Final(aDigest, &mdContext);
  81
  82         return PyString_FromStringAndSize((char *)aDigest, 16);
  83 }
  84
  85 PyDoc_STRVAR(digest_doc,
  86 "digest() -> string\n\
  87 \n\
  88 Return the digest of the strings passed to the update() method so\n\
  89 far. This is an 16-byte string which may contain non-ASCII characters,\n\
  90 including null bytes.");
  91
  92
  93 static PyObject *
  94 md5_hexdigest(md5object *self)
  95 {
  96         MD5_CTX mdContext;
  97         unsigned char digest[16];
  98         unsigned char hexdigest[32];
  99         int i, j;
 100
 101         /* make a temporary copy, and perform the final */
 102         mdContext = self->md5;
 103         MD5Final(digest, &mdContext);
 104
 105         /* Make hex version of the digest */
 106         for(i=j=0; i<16; i++) {
 107                 char c;
 108                 c = (digest[i] >> 4) & 0xf;
 109                 c = (c>9) ? c+'a'-10 : c + '0';
 110                 hexdigest[j++] = c;
 111                 c = (digest[i] & 0xf);
 112                 c = (c>9) ? c+'a'-10 : c + '0';
 113                 hexdigest[j++] = c;
 114         }
 115         return PyString_FromStringAndSize((char*)hexdigest, 32);
 116 }
 117
 118
 119 PyDoc_STRVAR(hexdigest_doc,
 120 "hexdigest() -> string\n\
 121 \n\
 122 Like digest(), but returns the digest as a string of hexadecimal digits.");
 123
 124
 125 static PyObject *
 126 md5_copy(md5object *self)
 127 {
 128         md5object *md5p;
 129
 130         if ((md5p = newmd5object()) == NULL)
 131                 return NULL;
 132
 133         md5p->md5 = self->md5;
 134
 135         return (PyObject *)md5p;
 136 }
 137
 138 PyDoc_STRVAR(copy_doc,
 139 "copy() -> md5 object\n\
 140 \n\
 141 Return a copy (``clone'') of the md5 object.");
 142
 143
 144 static PyMethodDef md5_methods[] = {
 145         {"update",    (PyCFunction)md5_update,    METH_VARARGS, update_doc},
 146         {"digest",    (PyCFunction)md5_digest,    METH_NOARGS,  digest_doc},
 147         {"hexdigest", (PyCFunction)md5_hexdigest, METH_NOARGS,  hexdigest_doc},
 148         {"copy",      (PyCFunction)md5_copy,      METH_NOARGS,  copy_doc},
 149         {NULL, NULL}                         /* sentinel */
 150 };
 151
 152 static PyObject *
 153 md5_getattr(md5object *self, char *name)
 154 {
 155         if (strcmp(name, "digest_size") == 0) {
 156                 return PyInt_FromLong(16);
 157         }
 158
 159         return Py_FindMethod(md5_methods, (PyObject *)self, name);
 160 }
 161
 162 PyDoc_STRVAR(module_doc,
 163 "This module implements the interface to RSA's MD5 message digest\n\
 164 algorithm (see also Internet RFC 1321). Its use is quite\n\
 165 straightforward: use the new() to create an md5 object. You can now\n\
 166 feed this object with arbitrary strings using the update() method, and\n\
 167 at any point you can ask it for the digest (a strong kind of 128-bit\n\
 168 checksum, a.k.a. ``fingerprint'') of the concatenation of the strings\n\
 169 fed to it so far using the digest() method.\n\
 170 \n\
 171 Functions:\n\
 172 \n\
 173 new([arg]) -- return a new md5 object, initialized with arg if provided\n\
 174 md5([arg]) -- DEPRECATED, same as new, but for compatibility\n\
 175 \n\
 176 Special Objects:\n\
 177 \n\
 178 MD5Type -- type object for md5 objects");
 179
 180 PyDoc_STRVAR(md5type_doc,
 181 "An md5 represents the object used to calculate the MD5 checksum of a\n\
 182 string of information.\n\
 183 \n\
 184 Methods:\n\
 185 \n\
 186 update() -- updates the current digest with an additional string\n\
 187 digest() -- return the current digest value\n\
 188 hexdigest() -- return the current digest as a string of hexadecimal digits\n\
 189 copy() -- return a copy of the current md5 object");
 190
 191 static PyTypeObject MD5type = {
 192         PyObject_HEAD_INIT(NULL)
 193         0,                        /*ob_size*/
 194         "md5.md5",                /*tp_name*/
 195         sizeof(md5object),        /*tp_size*/
 196         0,                        /*tp_itemsize*/
 197         /* methods */
 198         (destructor)md5_dealloc,  /*tp_dealloc*/
 199         0,                        /*tp_print*/
 200         (getattrfunc)md5_getattr, /*tp_getattr*/
 201         0,                        /*tp_setattr*/
 202         0,                        /*tp_compare*/
 203         0,                        /*tp_repr*/
 204         0,                        /*tp_as_number*/
 205         0,                        /*tp_as_sequence*/
 206         0,                        /*tp_as_mapping*/
 207         0,                        /*tp_hash*/
 208         0,                        /*tp_call*/
 209         0,                        /*tp_str*/
 210         0,                        /*tp_getattro*/
 211         0,                        /*tp_setattro*/
 212         0,                        /*tp_as_buffer*/
 213         0,                        /*tp_xxx4*/
 214         md5type_doc,              /*tp_doc*/
 215 };
 216
 217
 218 /* MD5 functions */
 219
 220 static PyObject *
 221 MD5_new(PyObject *self, PyObject *args)
 222 {
 223         md5object *md5p;
 224         unsigned char *cp = NULL;
 225         int len = 0;
 226
 227         if (!PyArg_ParseTuple(args, "|s#:new", &cp, &len))
 228                 return NULL;
 229
 230         if ((md5p = newmd5object()) == NULL)
 231                 return NULL;
 232
 233         if (cp)
 234                 MD5Update(&md5p->md5, cp, len);
 235
 236         return (PyObject *)md5p;
 237 }
 238
 239 PyDoc_STRVAR(new_doc,
 240 "new([arg]) -> md5 object\n\
 241 \n\
 242 Return a new md5 object. If arg is present, the method call update(arg)\n\
 243 is made.");
 244
 245
 246 /* List of functions exported by this module */
 247
 248 static PyMethodDef md5_functions[] = {
 249         {"new",         (PyCFunction)MD5_new, METH_VARARGS, new_doc},
 250         {"md5",         (PyCFunction)MD5_new, METH_VARARGS, new_doc}, /* Backward compatibility */
 251         {NULL,          NULL}   /* Sentinel */
 252 };
 253
 254
 255 /* Initialize this module. */
 256
 257 PyMODINIT_FUNC
 258 initmd5(void)
 259 {
 260         PyObject *m, *d;
 261
 262         MD5type.ob_type = &PyType_Type;
 263         m = Py_InitModule3("md5", md5_functions, module_doc);
 264         d = PyModule_GetDict(m);
 265         PyDict_SetItemString(d, "MD5Type", (PyObject *)&MD5type);
 266         PyModule_AddIntConstant(m, "digest_size", 16);
 267         /* No need to check the error here, the caller will do that */
 268 }