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 staticforward 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_Parse(args, "s#", &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 static char 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, PyObject *args)
  74 {
  75         MD5_CTX mdContext;
  76         unsigned char aDigest[16];
  77
  78         if (!PyArg_NoArgs(args))
  79                 return NULL;
  80
  81         /* make a temporary copy, and perform the final */
  82         mdContext = self->md5;
  83         MD5Final(aDigest, &mdContext);
  84
  85         return PyString_FromStringAndSize((char *)aDigest, 16);
  86 }
  87
  88 static char digest_doc [] =
  89 "digest() -> string\n\
  90 \n\
  91 Return the digest of the strings passed to the update() method so\n\
  92 far. This is an 16-byte string which may contain non-ASCII characters,\n\
  93 including null bytes.";
  94
  95
  96 static PyObject *
  97 md5_hexdigest(md5object *self, PyObject *args)
  98 {
  99         MD5_CTX mdContext;
 100         unsigned char digest[16];
 101         unsigned char hexdigest[32];
 102         int i, j;
 103
 104         if (!PyArg_NoArgs(args))
 105                 return NULL;
 106
 107         /* make a temporary copy, and perform the final */
 108         mdContext = self->md5;
 109         MD5Final(digest, &mdContext);
 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 static char 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, PyObject *args)
 133 {
 134         md5object *md5p;
 135
 136         if (!PyArg_NoArgs(args))
 137                 return NULL;
 138
 139         if ((md5p = newmd5object()) == NULL)
 140                 return NULL;
 141
 142         md5p->md5 = self->md5;
 143
 144         return (PyObject *)md5p;
 145 }
 146
 147 static char copy_doc [] =
 148 "copy() -> md5 object\n\
 149 \n\
 150 Return a copy (``clone'') of the md5 object.";
 151
 152
 153 static PyMethodDef md5_methods[] = {
 154         {"update",    (PyCFunction)md5_update,    METH_OLDARGS, update_doc},
 155         {"digest",    (PyCFunction)md5_digest,    METH_OLDARGS, digest_doc},
 156         {"hexdigest", (PyCFunction)md5_hexdigest, METH_OLDARGS, hexdigest_doc},
 157         {"copy",      (PyCFunction)md5_copy,      METH_OLDARGS, copy_doc},
 158         {NULL, NULL}                         /* sentinel */
 159 };
 160
 161 static PyObject *
 162 md5_getattr(md5object *self, char *name)
 163 {
 164         return Py_FindMethod(md5_methods, (PyObject *)self, name);
 165 }
 166
 167 static char module_doc [] =
 168
 169 "This module implements the interface to RSA's MD5 message digest\n\
 170 algorithm (see also Internet RFC 1321). Its use is quite\n\
 171 straightforward: use the new() to create an md5 object. You can now\n\
 172 feed this object with arbitrary strings using the update() method, and\n\
 173 at any point you can ask it for the digest (a strong kind of 128-bit\n\
 174 checksum, a.k.a. ``fingerprint'') of the concatenation of the strings\n\
 175 fed to it so far using the digest() method.\n\
 176 \n\
 177 Functions:\n\
 178 \n\
 179 new([arg]) -- return a new md5 object, initialized with arg if provided\n\
 180 md5([arg]) -- DEPRECATED, same as new, but for compatibility\n\
 181 \n\
 182 Special Objects:\n\
 183 \n\
 184 MD5Type -- type object for md5 objects\n\
 185 ";
 186
 187 static char md5type_doc [] =
 188 "An md5 represents the object used to calculate the MD5 checksum of a\n\
 189 string of information.\n\
 190 \n\
 191 Methods:\n\
 192 \n\
 193 update() -- updates the current digest with an additional string\n\
 194 digest() -- return the current digest value\n\
 195 copy() -- return a copy of the current md5 object\n\
 196 ";
 197
 198 statichere PyTypeObject MD5type = {
 199         PyObject_HEAD_INIT(NULL)
 200         0,                        /*ob_size*/
 201         "md5",                    /*tp_name*/
 202         sizeof(md5object),        /*tp_size*/
 203         0,                        /*tp_itemsize*/
 204         /* methods */
 205         (destructor)md5_dealloc,  /*tp_dealloc*/
 206         0,                        /*tp_print*/
 207         (getattrfunc)md5_getattr, /*tp_getattr*/
 208         0,                        /*tp_setattr*/
 209         0,                        /*tp_compare*/
 210         0,                        /*tp_repr*/
 211         0,                        /*tp_as_number*/
 212         0,                        /*tp_as_sequence*/
 213         0,                        /*tp_as_mapping*/
 214         0,                        /*tp_hash*/
 215         0,                        /*tp_call*/
 216         0,                        /*tp_str*/
 217         0,                        /*tp_getattro*/
 218         0,                        /*tp_setattro*/
 219         0,                        /*tp_as_buffer*/
 220         0,                        /*tp_xxx4*/
 221         md5type_doc,              /*tp_doc*/
 222 };
 223
 224
 225 /* MD5 functions */
 226
 227 static PyObject *
 228 MD5_new(PyObject *self, PyObject *args)
 229 {
 230         md5object *md5p;
 231         unsigned char *cp = NULL;
 232         int len = 0;
 233
 234         if (!PyArg_ParseTuple(args, "|s#:new", &cp, &len))
 235                 return NULL;
 236
 237         if ((md5p = newmd5object()) == NULL)
 238                 return NULL;
 239
 240         if (cp)
 241                 MD5Update(&md5p->md5, cp, len);
 242
 243         return (PyObject *)md5p;
 244 }
 245
 246 static char new_doc [] =
 247 "new([arg]) -> md5 object\n\
 248 \n\
 249 Return a new md5 object. If arg is present, the method call update(arg)\n\
 250 is made.";
 251
 252
 253 /* List of functions exported by this module */
 254
 255 static PyMethodDef md5_functions[] = {
 256         {"new",         (PyCFunction)MD5_new, METH_VARARGS, new_doc},
 257         {"md5",         (PyCFunction)MD5_new, METH_VARARGS, new_doc}, /* Backward compatibility */
 258         {NULL,          NULL}   /* Sentinel */
 259 };
 260
 261
 262 /* Initialize this module. */
 263
 264 DL_EXPORT(void)
 265 initmd5(void)
 266 {
 267         PyObject *m, *d;
 268
 269         MD5type.ob_type = &PyType_Type;
 270         m = Py_InitModule3("md5", md5_functions, module_doc);
 271         d = PyModule_GetDict(m);
 272         PyDict_SetItemString(d, "MD5Type", (PyObject *)&MD5type);
 273         /* No need to check the error here, the caller will do that */
 274 }