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Updated for 2.1a3
[python/dscho.git] / Modules / shamodule.c
blob8bfcec7b82b71db4cb144069410f7323c7c21168
1 /* SHA module */
2
3 /* This module provides an interface to NIST's Secure Hash Algorithm */
4
5 /* See below for information about the original code this module was
6 based upon. Additional work performed by:
7
8 Andrew Kuchling (amk1@bigfoot.com)
9 Greg Stein (gstein@lyra.org)
10 */
11
12 /* SHA objects */
13
14 #include "Python.h"
15
16
17 /* Endianness testing and definitions */
18 #define TestEndianness(variable) {int i=1; variable=PCT_BIG_ENDIAN;\
19 if (*((char*)&i)==1) variable=PCT_LITTLE_ENDIAN;}
20
21 #define PCT_LITTLE_ENDIAN 1
22 #define PCT_BIG_ENDIAN 0
23
24 /* Some useful types */
25
26 typedef unsigned char SHA_BYTE;
27
28 #if SIZEOF_INT == 4
29 typedef unsigned int SHA_INT32; /* 32-bit integer */
30 #else
31 /* not defined. compilation will die. */
32 #endif
33
34 /* The SHA block size and message digest sizes, in bytes */
35
36 #define SHA_BLOCKSIZE 64
37 #define SHA_DIGESTSIZE 20
38
39 /* The structure for storing SHS info */
40
41 typedef struct {
42 PyObject_HEAD
43 SHA_INT32 digest[5]; /* Message digest */
44 SHA_INT32 count_lo, count_hi; /* 64-bit bit count */
45 SHA_BYTE data[SHA_BLOCKSIZE]; /* SHA data buffer */
46 int Endianness;
47 int local; /* unprocessed amount in data */
48 } SHAobject;
49
50 /* When run on a little-endian CPU we need to perform byte reversal on an
51 array of longwords. */
52
53 static void longReverse(SHA_INT32 *buffer, int byteCount, int Endianness)
54 {
55 SHA_INT32 value;
56
57 if ( Endianness == PCT_BIG_ENDIAN )
58 return;
59
60 byteCount /= sizeof(*buffer);
61 while (byteCount--) {
62 value = *buffer;
63 value = ( ( value & 0xFF00FF00L ) >> 8 ) | \
64 ( ( value & 0x00FF00FFL ) << 8 );
65 *buffer++ = ( value << 16 ) | ( value >> 16 );
66 }
67 }
68
69 static void SHAcopy(SHAobject *src, SHAobject *dest)
70 {
71 dest->Endianness = src->Endianness;
72 dest->local = src->local;
73 dest->count_lo = src->count_lo;
74 dest->count_hi = src->count_hi;
75 memcpy(dest->digest, src->digest, sizeof(src->digest));
76 memcpy(dest->data, src->data, sizeof(src->data));
77 }
78
79
80 /* ------------------------------------------------------------------------
81 *
82 * This code for the SHA algorithm was noted as public domain. The original
83 * headers are pasted below.
84 *
85 * Several changes have been made to make it more compatible with the
86 * Python environment and desired interface.
87 *
88 */
89
90 /* NIST Secure Hash Algorithm */
91 /* heavily modified by Uwe Hollerbach <uh@alumni.caltech edu> */
92 /* from Peter C. Gutmann's implementation as found in */
93 /* Applied Cryptography by Bruce Schneier */
94 /* Further modifications to include the "UNRAVEL" stuff, below */
95
96 /* This code is in the public domain */
97
98 /* UNRAVEL should be fastest & biggest */
99 /* UNROLL_LOOPS should be just as big, but slightly slower */
100 /* both undefined should be smallest and slowest */
101
102 #define UNRAVEL
103 /* #define UNROLL_LOOPS */
104
105 /* The SHA f()-functions. The f1 and f3 functions can be optimized to
106 save one boolean operation each - thanks to Rich Schroeppel,
107 rcs@cs.arizona.edu for discovering this */
108
109 /*#define f1(x,y,z) ((x & y) | (~x & z)) // Rounds 0-19 */
110 #define f1(x,y,z) (z ^ (x & (y ^ z))) /* Rounds 0-19 */
111 #define f2(x,y,z) (x ^ y ^ z) /* Rounds 20-39 */
112 /*#define f3(x,y,z) ((x & y) | (x & z) | (y & z)) // Rounds 40-59 */
113 #define f3(x,y,z) ((x & y) | (z & (x | y))) /* Rounds 40-59 */
114 #define f4(x,y,z) (x ^ y ^ z) /* Rounds 60-79 */
115
116 /* SHA constants */
117
118 #define CONST1 0x5a827999L /* Rounds 0-19 */
119 #define CONST2 0x6ed9eba1L /* Rounds 20-39 */
120 #define CONST3 0x8f1bbcdcL /* Rounds 40-59 */
121 #define CONST4 0xca62c1d6L /* Rounds 60-79 */
122
123 /* 32-bit rotate */
124
125 #define R32(x,n) ((x << n) | (x >> (32 - n)))
126
127 /* the generic case, for when the overall rotation is not unraveled */
128
129 #define FG(n) \
130 T = R32(A,5) + f##n(B,C,D) + E + *WP++ + CONST##n; \
131 E = D; D = C; C = R32(B,30); B = A; A = T
132
133 /* specific cases, for when the overall rotation is unraveled */
134
135 #define FA(n) \
136 T = R32(A,5) + f##n(B,C,D) + E + *WP++ + CONST##n; B = R32(B,30)
137
138 #define FB(n) \
139 E = R32(T,5) + f##n(A,B,C) + D + *WP++ + CONST##n; A = R32(A,30)
140
141 #define FC(n) \
142 D = R32(E,5) + f##n(T,A,B) + C + *WP++ + CONST##n; T = R32(T,30)
143
144 #define FD(n) \
145 C = R32(D,5) + f##n(E,T,A) + B + *WP++ + CONST##n; E = R32(E,30)
146
147 #define FE(n) \
148 B = R32(C,5) + f##n(D,E,T) + A + *WP++ + CONST##n; D = R32(D,30)
149
150 #define FT(n) \
151 A = R32(B,5) + f##n(C,D,E) + T + *WP++ + CONST##n; C = R32(C,30)
152
153 /* do SHA transformation */
154
155 static void
156 sha_transform(SHAobject *sha_info)
157 {
158 int i;
159 SHA_INT32 T, A, B, C, D, E, W[80], *WP;
160
161 memcpy(W, sha_info->data, sizeof(sha_info->data));
162 longReverse(W, (int)sizeof(sha_info->data), sha_info->Endianness);
163
164 for (i = 16; i < 80; ++i) {
165 W[i] = W[i-3] ^ W[i-8] ^ W[i-14] ^ W[i-16];
166
167 /* extra rotation fix */
168 W[i] = R32(W[i], 1);
169 }
170 A = sha_info->digest[0];
171 B = sha_info->digest[1];
172 C = sha_info->digest[2];
173 D = sha_info->digest[3];
174 E = sha_info->digest[4];
175 WP = W;
176 #ifdef UNRAVEL
177 FA(1); FB(1); FC(1); FD(1); FE(1); FT(1); FA(1); FB(1); FC(1); FD(1);
178 FE(1); FT(1); FA(1); FB(1); FC(1); FD(1); FE(1); FT(1); FA(1); FB(1);
179 FC(2); FD(2); FE(2); FT(2); FA(2); FB(2); FC(2); FD(2); FE(2); FT(2);
180 FA(2); FB(2); FC(2); FD(2); FE(2); FT(2); FA(2); FB(2); FC(2); FD(2);
181 FE(3); FT(3); FA(3); FB(3); FC(3); FD(3); FE(3); FT(3); FA(3); FB(3);
182 FC(3); FD(3); FE(3); FT(3); FA(3); FB(3); FC(3); FD(3); FE(3); FT(3);
183 FA(4); FB(4); FC(4); FD(4); FE(4); FT(4); FA(4); FB(4); FC(4); FD(4);
184 FE(4); FT(4); FA(4); FB(4); FC(4); FD(4); FE(4); FT(4); FA(4); FB(4);
185 sha_info->digest[0] += E;
186 sha_info->digest[1] += T;
187 sha_info->digest[2] += A;
188 sha_info->digest[3] += B;
189 sha_info->digest[4] += C;
190 #else /* !UNRAVEL */
191 #ifdef UNROLL_LOOPS
192 FG(1); FG(1); FG(1); FG(1); FG(1); FG(1); FG(1); FG(1); FG(1); FG(1);
193 FG(1); FG(1); FG(1); FG(1); FG(1); FG(1); FG(1); FG(1); FG(1); FG(1);
194 FG(2); FG(2); FG(2); FG(2); FG(2); FG(2); FG(2); FG(2); FG(2); FG(2);
195 FG(2); FG(2); FG(2); FG(2); FG(2); FG(2); FG(2); FG(2); FG(2); FG(2);
196 FG(3); FG(3); FG(3); FG(3); FG(3); FG(3); FG(3); FG(3); FG(3); FG(3);
197 FG(3); FG(3); FG(3); FG(3); FG(3); FG(3); FG(3); FG(3); FG(3); FG(3);
198 FG(4); FG(4); FG(4); FG(4); FG(4); FG(4); FG(4); FG(4); FG(4); FG(4);
199 FG(4); FG(4); FG(4); FG(4); FG(4); FG(4); FG(4); FG(4); FG(4); FG(4);
200 #else /* !UNROLL_LOOPS */
201 for (i = 0; i < 20; ++i) { FG(1); }
202 for (i = 20; i < 40; ++i) { FG(2); }
203 for (i = 40; i < 60; ++i) { FG(3); }
204 for (i = 60; i < 80; ++i) { FG(4); }
205 #endif /* !UNROLL_LOOPS */
206 sha_info->digest[0] += A;
207 sha_info->digest[1] += B;
208 sha_info->digest[2] += C;
209 sha_info->digest[3] += D;
210 sha_info->digest[4] += E;
211 #endif /* !UNRAVEL */
212 }
213
214 /* initialize the SHA digest */
215
216 static void
217 sha_init(SHAobject *sha_info)
218 {
219 TestEndianness(sha_info->Endianness)
220
221 sha_info->digest[0] = 0x67452301L;
222 sha_info->digest[1] = 0xefcdab89L;
223 sha_info->digest[2] = 0x98badcfeL;
224 sha_info->digest[3] = 0x10325476L;
225 sha_info->digest[4] = 0xc3d2e1f0L;
226 sha_info->count_lo = 0L;
227 sha_info->count_hi = 0L;
228 sha_info->local = 0;
229 }
230
231 /* update the SHA digest */
232
233 static void
234 sha_update(SHAobject *sha_info, SHA_BYTE *buffer, int count)
235 {
236 int i;
237 SHA_INT32 clo;
238
239 clo = sha_info->count_lo + ((SHA_INT32) count << 3);
240 if (clo < sha_info->count_lo) {
241 ++sha_info->count_hi;
242 }
243 sha_info->count_lo = clo;
244 sha_info->count_hi += (SHA_INT32) count >> 29;
245 if (sha_info->local) {
246 i = SHA_BLOCKSIZE - sha_info->local;
247 if (i > count) {
248 i = count;
249 }
250 memcpy(((SHA_BYTE *) sha_info->data) + sha_info->local, buffer, i);
251 count -= i;
252 buffer += i;
253 sha_info->local += i;
254 if (sha_info->local == SHA_BLOCKSIZE) {
255 sha_transform(sha_info);
256 }
257 else {
258 return;
259 }
260 }
261 while (count >= SHA_BLOCKSIZE) {
262 memcpy(sha_info->data, buffer, SHA_BLOCKSIZE);
263 buffer += SHA_BLOCKSIZE;
264 count -= SHA_BLOCKSIZE;
265 sha_transform(sha_info);
266 }
267 memcpy(sha_info->data, buffer, count);
268 sha_info->local = count;
269 }
270
271 /* finish computing the SHA digest */
272
273 static void
274 sha_final(unsigned char digest[20], SHAobject *sha_info)
275 {
276 int count;
277 SHA_INT32 lo_bit_count, hi_bit_count;
278
279 lo_bit_count = sha_info->count_lo;
280 hi_bit_count = sha_info->count_hi;
281 count = (int) ((lo_bit_count >> 3) & 0x3f);
282 ((SHA_BYTE *) sha_info->data)[count++] = 0x80;
283 if (count > SHA_BLOCKSIZE - 8) {
284 memset(((SHA_BYTE *) sha_info->data) + count, 0,
285 SHA_BLOCKSIZE - count);
286 sha_transform(sha_info);
287 memset((SHA_BYTE *) sha_info->data, 0, SHA_BLOCKSIZE - 8);
288 }
289 else {
290 memset(((SHA_BYTE *) sha_info->data) + count, 0,
291 SHA_BLOCKSIZE - 8 - count);
292 }
293
294 /* GJS: note that we add the hi/lo in big-endian. sha_transform will
295 swap these values into host-order. */
296 sha_info->data[56] = (hi_bit_count >> 24) & 0xff;
297 sha_info->data[57] = (hi_bit_count >> 16) & 0xff;
298 sha_info->data[58] = (hi_bit_count >> 8) & 0xff;
299 sha_info->data[59] = (hi_bit_count >> 0) & 0xff;
300 sha_info->data[60] = (lo_bit_count >> 24) & 0xff;
301 sha_info->data[61] = (lo_bit_count >> 16) & 0xff;
302 sha_info->data[62] = (lo_bit_count >> 8) & 0xff;
303 sha_info->data[63] = (lo_bit_count >> 0) & 0xff;
304 sha_transform(sha_info);
305 digest[ 0] = (unsigned char) ((sha_info->digest[0] >> 24) & 0xff);
306 digest[ 1] = (unsigned char) ((sha_info->digest[0] >> 16) & 0xff);
307 digest[ 2] = (unsigned char) ((sha_info->digest[0] >> 8) & 0xff);
308 digest[ 3] = (unsigned char) ((sha_info->digest[0] ) & 0xff);
309 digest[ 4] = (unsigned char) ((sha_info->digest[1] >> 24) & 0xff);
310 digest[ 5] = (unsigned char) ((sha_info->digest[1] >> 16) & 0xff);
311 digest[ 6] = (unsigned char) ((sha_info->digest[1] >> 8) & 0xff);
312 digest[ 7] = (unsigned char) ((sha_info->digest[1] ) & 0xff);
313 digest[ 8] = (unsigned char) ((sha_info->digest[2] >> 24) & 0xff);
314 digest[ 9] = (unsigned char) ((sha_info->digest[2] >> 16) & 0xff);
315 digest[10] = (unsigned char) ((sha_info->digest[2] >> 8) & 0xff);
316 digest[11] = (unsigned char) ((sha_info->digest[2] ) & 0xff);
317 digest[12] = (unsigned char) ((sha_info->digest[3] >> 24) & 0xff);
318 digest[13] = (unsigned char) ((sha_info->digest[3] >> 16) & 0xff);
319 digest[14] = (unsigned char) ((sha_info->digest[3] >> 8) & 0xff);
320 digest[15] = (unsigned char) ((sha_info->digest[3] ) & 0xff);
321 digest[16] = (unsigned char) ((sha_info->digest[4] >> 24) & 0xff);
322 digest[17] = (unsigned char) ((sha_info->digest[4] >> 16) & 0xff);
323 digest[18] = (unsigned char) ((sha_info->digest[4] >> 8) & 0xff);
324 digest[19] = (unsigned char) ((sha_info->digest[4] ) & 0xff);
325 }
326
327 /*
328 * End of copied SHA code.
329 *
330 * ------------------------------------------------------------------------
331 */
332
333 staticforward PyTypeObject SHAtype;
334
335
336 static SHAobject *
337 newSHAobject(void)
338 {
339 return (SHAobject *)PyObject_New(SHAobject, &SHAtype);
340 }
341
342 /* Internal methods for a hashing object */
343
344 static void
345 SHA_dealloc(PyObject *ptr)
346 {
347 PyObject_Del(ptr);
348 }
349
350
351 /* External methods for a hashing object */
352
353 static char SHA_copy__doc__[] =
354 "Return a copy of the hashing object.";
355
356 static PyObject *
357 SHA_copy(SHAobject *self, PyObject *args)
358 {
359 SHAobject *newobj;
360
361 if (!PyArg_ParseTuple(args, ":copy")) {
362 return NULL;
363 }
364 if ( (newobj = newSHAobject())==NULL)
365 return NULL;
366
367 SHAcopy(self, newobj);
368 return (PyObject *)newobj;
369 }
370
371 static char SHA_digest__doc__[] =
372 "Return the digest value as a string of binary data.";
373
374 static PyObject *
375 SHA_digest(SHAobject *self, PyObject *args)
376 {
377 unsigned char digest[SHA_DIGESTSIZE];
378 SHAobject temp;
379
380 if (!PyArg_ParseTuple(args, ":digest"))
381 return NULL;
382
383 SHAcopy(self, &temp);
384 sha_final(digest, &temp);
385 return PyString_FromStringAndSize((const char *)digest, sizeof(digest));
386 }
387
388 static char SHA_hexdigest__doc__[] =
389 "Return the digest value as a string of hexadecimal digits.";
390
391 static PyObject *
392 SHA_hexdigest(SHAobject *self, PyObject *args)
393 {
394 unsigned char digest[SHA_DIGESTSIZE];
395 SHAobject temp;
396 PyObject *retval;
397 char *hex_digest;
398 int i, j;
399
400 if (!PyArg_ParseTuple(args, ":hexdigest"))
401 return NULL;
402
403 /* Get the raw (binary) digest value */
404 SHAcopy(self, &temp);
405 sha_final(digest, &temp);
406
407 /* Create a new string */
408 retval = PyString_FromStringAndSize(NULL, sizeof(digest) * 2);
409 if (!retval)
410 return NULL;
411 hex_digest = PyString_AsString(retval);
412 if (!hex_digest) {
413 Py_DECREF(retval);
414 return NULL;
415 }
416
417 /* Make hex version of the digest */
418 for(i=j=0; i<sizeof(digest); i++) {
419 char c;
420 c = (digest[i] >> 4) & 0xf;
421 c = (c>9) ? c+'a'-10 : c + '0';
422 hex_digest[j++] = c;
423 c = (digest[i] & 0xf);
424 c = (c>9) ? c+'a'-10 : c + '0';
425 hex_digest[j++] = c;
426 }
427 return retval;
428 }
429
430 static char SHA_update__doc__[] =
431 "Update this hashing object's state with the provided string.";
432
433 static PyObject *
434 SHA_update(SHAobject *self, PyObject *args)
435 {
436 unsigned char *cp;
437 int len;
438
439 if (!PyArg_ParseTuple(args, "s#:update", &cp, &len))
440 return NULL;
441
442 sha_update(self, cp, len);
443
444 Py_INCREF(Py_None);
445 return Py_None;
446 }
447
448 static PyMethodDef SHA_methods[] = {
449 {"copy", (PyCFunction)SHA_copy, METH_VARARGS, SHA_copy__doc__},
450 {"digest", (PyCFunction)SHA_digest, METH_VARARGS, SHA_digest__doc__},
451 {"hexdigest", (PyCFunction)SHA_hexdigest, METH_VARARGS, SHA_hexdigest__doc__},
452 {"update", (PyCFunction)SHA_update, METH_VARARGS, SHA_update__doc__},
453 {NULL, NULL} /* sentinel */
454 };
455
456 static PyObject *
457 SHA_getattr(PyObject *self, char *name)
458 {
459 if (strcmp(name, "blocksize")==0)
460 return PyInt_FromLong(1);
461 if (strcmp(name, "digestsize")==0)
462 return PyInt_FromLong(20);
463
464 return Py_FindMethod(SHA_methods, self, name);
465 }
466
467 static PyTypeObject SHAtype = {
468 PyObject_HEAD_INIT(NULL)
469 0, /*ob_size*/
470 "SHA", /*tp_name*/
471 sizeof(SHAobject), /*tp_size*/
472 0, /*tp_itemsize*/
473 /* methods */
474 SHA_dealloc, /*tp_dealloc*/
475 0, /*tp_print*/
476 SHA_getattr, /*tp_getattr*/
477 };
478
479
480 /* The single module-level function: new() */
481
482 static char SHA_new__doc__[] =
483 "Return a new SHA hashing object. An optional string "
484 "argument may be provided; if present, this string will be "
485 " automatically hashed.";
486
487 static PyObject *
488 SHA_new(PyObject *self, PyObject *args, PyObject *kwdict)
489 {
490 static char *kwlist[] = {"string", NULL};
491 SHAobject *new;
492 unsigned char *cp = NULL;
493 int len;
494
495 if (!PyArg_ParseTupleAndKeywords(args, kwdict, "|s#:new", kwlist,
496 &cp, &len)) {
497 return NULL;
498 }
499
500 if ((new = newSHAobject()) == NULL)
501 return NULL;
502
503 sha_init(new);
504
505 if (PyErr_Occurred()) {
506 Py_DECREF(new);
507 return NULL;
508 }
509 if (cp)
510 sha_update(new, cp, len);
511
512 return (PyObject *)new;
513 }
514
515
516 /* List of functions exported by this module */
517
518 static struct PyMethodDef SHA_functions[] = {
519 {"new", (PyCFunction)SHA_new, METH_VARARGS|METH_KEYWORDS, SHA_new__doc__},
520 {"sha", (PyCFunction)SHA_new, METH_VARARGS|METH_KEYWORDS, SHA_new__doc__},
521 {NULL, NULL} /* Sentinel */
522 };
523
524
525 /* Initialize this module. */
526
527 #define insint(n,v) { PyObject *o=PyInt_FromLong(v); \
528 if (o!=NULL) PyDict_SetItemString(d,n,o); \
529 Py_XDECREF(o); }
530
531 DL_EXPORT(void)
532 initsha(void)
533 {
534 PyObject *d, *m;
535
536 SHAtype.ob_type = &PyType_Type;
537 m = Py_InitModule("sha", SHA_functions);
538
539 /* Add some symbolic constants to the module */
540 d = PyModule_GetDict(m);
541 insint("blocksize", 1); /* For future use, in case some hash
542 functions require an integral number of
543 blocks */
544 insint("digestsize", 20);
545 }