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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 (amk@amk.ca)
9    Greg Stein (gstein@lyra.org)
10 
11    Copyright (C) 2005   Gregory P. Smith (greg@krypto.org)
12    Licensed to PSF under a Contributor Agreement.
13 
14 */
15 
16 /* SHA objects */
17 
18 #include "Python.h"
19 #include "structmember.h"
20 
21 
22 /* Endianness testing and definitions */
23 #define TestEndianness(variable) {int i=1; variable=PCT_BIG_ENDIAN;\
24         if (*((char*)&i)==1) variable=PCT_LITTLE_ENDIAN;}
25 
26 #define PCT_LITTLE_ENDIAN 1
27 #define PCT_BIG_ENDIAN 0
28 
29 /* Some useful types */
30 
31 typedef unsigned char SHA_BYTE;
32 
33 #if SIZEOF_INT == 4
34 typedef unsigned int SHA_INT32; /* 32-bit integer */
35 #else
36 /* not defined. compilation will die. */
37 #endif
38 
39 /* The SHA block size and message digest sizes, in bytes */
40 
41 #define SHA_BLOCKSIZE    64
42 #define SHA_DIGESTSIZE  20
43 
44 /* The structure for storing SHS info */
45 
46 typedef struct {
47     PyObject_HEAD
48     SHA_INT32 digest[5];                /* Message digest */
49     SHA_INT32 count_lo, count_hi;       /* 64-bit bit count */
50     SHA_BYTE data[SHA_BLOCKSIZE];       /* SHA data buffer */
51     int Endianness;
52     int local;                          /* unprocessed amount in data */
53 } SHAobject;
54 
55 /* When run on a little-endian CPU we need to perform byte reversal on an
56    array of longwords. */
57 
longReverse(SHA_INT32 * buffer,int byteCount,int Endianness)58 static void longReverse(SHA_INT32 *buffer, int byteCount, int Endianness)
59 {
60     SHA_INT32 value;
61 
62     if ( Endianness == PCT_BIG_ENDIAN )
63         return;
64 
65     byteCount /= sizeof(*buffer);
66     while (byteCount--) {
67         value = *buffer;
68         value = ( ( value & 0xFF00FF00L ) >> 8  ) | \
69                 ( ( value & 0x00FF00FFL ) << 8 );
70         *buffer++ = ( value << 16 ) | ( value >> 16 );
71     }
72 }
73 
SHAcopy(SHAobject * src,SHAobject * dest)74 static void SHAcopy(SHAobject *src, SHAobject *dest)
75 {
76     dest->Endianness = src->Endianness;
77     dest->local = src->local;
78     dest->count_lo = src->count_lo;
79     dest->count_hi = src->count_hi;
80     memcpy(dest->digest, src->digest, sizeof(src->digest));
81     memcpy(dest->data, src->data, sizeof(src->data));
82 }
83 
84 
85 /* ------------------------------------------------------------------------
86  *
87  * This code for the SHA algorithm was noted as public domain. The original
88  * headers are pasted below.
89  *
90  * Several changes have been made to make it more compatible with the
91  * Python environment and desired interface.
92  *
93  */
94 
95 /* NIST Secure Hash Algorithm */
96 /* heavily modified by Uwe Hollerbach <uh@alumni.caltech edu> */
97 /* from Peter C. Gutmann's implementation as found in */
98 /* Applied Cryptography by Bruce Schneier */
99 /* Further modifications to include the "UNRAVEL" stuff, below */
100 
101 /* This code is in the public domain */
102 
103 /* UNRAVEL should be fastest & biggest */
104 /* UNROLL_LOOPS should be just as big, but slightly slower */
105 /* both undefined should be smallest and slowest */
106 
107 #define UNRAVEL
108 /* #define UNROLL_LOOPS */
109 
110 /* The SHA f()-functions.  The f1 and f3 functions can be optimized to
111    save one boolean operation each - thanks to Rich Schroeppel,
112    rcs@cs.arizona.edu for discovering this */
113 
114 /*#define f1(x,y,z)     ((x & y) | (~x & z))            // Rounds  0-19 */
115 #define f1(x,y,z)       (z ^ (x & (y ^ z)))             /* Rounds  0-19 */
116 #define f2(x,y,z)       (x ^ y ^ z)                     /* Rounds 20-39 */
117 /*#define f3(x,y,z)     ((x & y) | (x & z) | (y & z))   // Rounds 40-59 */
118 #define f3(x,y,z)       ((x & y) | (z & (x | y)))       /* Rounds 40-59 */
119 #define f4(x,y,z)       (x ^ y ^ z)                     /* Rounds 60-79 */
120 
121 /* SHA constants */
122 
123 #define CONST1          0x5a827999L                     /* Rounds  0-19 */
124 #define CONST2          0x6ed9eba1L                     /* Rounds 20-39 */
125 #define CONST3          0x8f1bbcdcL                     /* Rounds 40-59 */
126 #define CONST4          0xca62c1d6L                     /* Rounds 60-79 */
127 
128 /* 32-bit rotate */
129 
130 #define R32(x,n)        ((x << n) | (x >> (32 - n)))
131 
132 /* the generic case, for when the overall rotation is not unraveled */
133 
134 #define FG(n)   \
135     T = R32(A,5) + f##n(B,C,D) + E + *WP++ + CONST##n;  \
136     E = D; D = C; C = R32(B,30); B = A; A = T
137 
138 /* specific cases, for when the overall rotation is unraveled */
139 
140 #define FA(n)   \
141     T = R32(A,5) + f##n(B,C,D) + E + *WP++ + CONST##n; B = R32(B,30)
142 
143 #define FB(n)   \
144     E = R32(T,5) + f##n(A,B,C) + D + *WP++ + CONST##n; A = R32(A,30)
145 
146 #define FC(n)   \
147     D = R32(E,5) + f##n(T,A,B) + C + *WP++ + CONST##n; T = R32(T,30)
148 
149 #define FD(n)   \
150     C = R32(D,5) + f##n(E,T,A) + B + *WP++ + CONST##n; E = R32(E,30)
151 
152 #define FE(n)   \
153     B = R32(C,5) + f##n(D,E,T) + A + *WP++ + CONST##n; D = R32(D,30)
154 
155 #define FT(n)   \
156     A = R32(B,5) + f##n(C,D,E) + T + *WP++ + CONST##n; C = R32(C,30)
157 
158 /* do SHA transformation */
159 
160 static void
sha_transform(SHAobject * sha_info)161 sha_transform(SHAobject *sha_info)
162 {
163     int i;
164     SHA_INT32 T, A, B, C, D, E, W[80], *WP;
165 
166     memcpy(W, sha_info->data, sizeof(sha_info->data));
167     longReverse(W, (int)sizeof(sha_info->data), sha_info->Endianness);
168 
169     for (i = 16; i < 80; ++i) {
170         W[i] = W[i-3] ^ W[i-8] ^ W[i-14] ^ W[i-16];
171 
172         /* extra rotation fix */
173         W[i] = R32(W[i], 1);
174     }
175     A = sha_info->digest[0];
176     B = sha_info->digest[1];
177     C = sha_info->digest[2];
178     D = sha_info->digest[3];
179     E = sha_info->digest[4];
180     WP = W;
181 #ifdef UNRAVEL
182     FA(1); FB(1); FC(1); FD(1); FE(1); FT(1); FA(1); FB(1); FC(1); FD(1);
183     FE(1); FT(1); FA(1); FB(1); FC(1); FD(1); FE(1); FT(1); FA(1); FB(1);
184     FC(2); FD(2); FE(2); FT(2); FA(2); FB(2); FC(2); FD(2); FE(2); FT(2);
185     FA(2); FB(2); FC(2); FD(2); FE(2); FT(2); FA(2); FB(2); FC(2); FD(2);
186     FE(3); FT(3); FA(3); FB(3); FC(3); FD(3); FE(3); FT(3); FA(3); FB(3);
187     FC(3); FD(3); FE(3); FT(3); FA(3); FB(3); FC(3); FD(3); FE(3); FT(3);
188     FA(4); FB(4); FC(4); FD(4); FE(4); FT(4); FA(4); FB(4); FC(4); FD(4);
189     FE(4); FT(4); FA(4); FB(4); FC(4); FD(4); FE(4); FT(4); FA(4); FB(4);
190     sha_info->digest[0] += E;
191     sha_info->digest[1] += T;
192     sha_info->digest[2] += A;
193     sha_info->digest[3] += B;
194     sha_info->digest[4] += C;
195 #else /* !UNRAVEL */
196 #ifdef UNROLL_LOOPS
197     FG(1); FG(1); FG(1); FG(1); FG(1); FG(1); FG(1); FG(1); FG(1); FG(1);
198     FG(1); FG(1); FG(1); FG(1); FG(1); FG(1); FG(1); FG(1); FG(1); FG(1);
199     FG(2); FG(2); FG(2); FG(2); FG(2); FG(2); FG(2); FG(2); FG(2); FG(2);
200     FG(2); FG(2); FG(2); FG(2); FG(2); FG(2); FG(2); FG(2); FG(2); FG(2);
201     FG(3); FG(3); FG(3); FG(3); FG(3); FG(3); FG(3); FG(3); FG(3); FG(3);
202     FG(3); FG(3); FG(3); FG(3); FG(3); FG(3); FG(3); FG(3); FG(3); FG(3);
203     FG(4); FG(4); FG(4); FG(4); FG(4); FG(4); FG(4); FG(4); FG(4); FG(4);
204     FG(4); FG(4); FG(4); FG(4); FG(4); FG(4); FG(4); FG(4); FG(4); FG(4);
205 #else /* !UNROLL_LOOPS */
206     for (i =  0; i < 20; ++i) { FG(1); }
207     for (i = 20; i < 40; ++i) { FG(2); }
208     for (i = 40; i < 60; ++i) { FG(3); }
209     for (i = 60; i < 80; ++i) { FG(4); }
210 #endif /* !UNROLL_LOOPS */
211     sha_info->digest[0] += A;
212     sha_info->digest[1] += B;
213     sha_info->digest[2] += C;
214     sha_info->digest[3] += D;
215     sha_info->digest[4] += E;
216 #endif /* !UNRAVEL */
217 }
218 
219 /* initialize the SHA digest */
220 
221 static void
sha_init(SHAobject * sha_info)222 sha_init(SHAobject *sha_info)
223 {
224     TestEndianness(sha_info->Endianness)
225 
226     sha_info->digest[0] = 0x67452301L;
227     sha_info->digest[1] = 0xefcdab89L;
228     sha_info->digest[2] = 0x98badcfeL;
229     sha_info->digest[3] = 0x10325476L;
230     sha_info->digest[4] = 0xc3d2e1f0L;
231     sha_info->count_lo = 0L;
232     sha_info->count_hi = 0L;
233     sha_info->local = 0;
234 }
235 
236 /* update the SHA digest */
237 
238 static void
sha_update(SHAobject * sha_info,SHA_BYTE * buffer,unsigned int count)239 sha_update(SHAobject *sha_info, SHA_BYTE *buffer, unsigned int count)
240 {
241     unsigned int i;
242     SHA_INT32 clo;
243 
244     clo = sha_info->count_lo + ((SHA_INT32) count << 3);
245     if (clo < sha_info->count_lo) {
246         ++sha_info->count_hi;
247     }
248     sha_info->count_lo = clo;
249     sha_info->count_hi += (SHA_INT32) count >> 29;
250     if (sha_info->local) {
251         i = SHA_BLOCKSIZE - sha_info->local;
252         if (i > count) {
253             i = count;
254         }
255         memcpy(((SHA_BYTE *) sha_info->data) + sha_info->local, buffer, i);
256         count -= i;
257         buffer += i;
258         sha_info->local += i;
259         if (sha_info->local == SHA_BLOCKSIZE) {
260             sha_transform(sha_info);
261         }
262         else {
263             return;
264         }
265     }
266     while (count >= SHA_BLOCKSIZE) {
267         memcpy(sha_info->data, buffer, SHA_BLOCKSIZE);
268         buffer += SHA_BLOCKSIZE;
269         count -= SHA_BLOCKSIZE;
270         sha_transform(sha_info);
271     }
272     memcpy(sha_info->data, buffer, count);
273     sha_info->local = count;
274 }
275 
276 /* finish computing the SHA digest */
277 
278 static void
sha_final(unsigned char digest[20],SHAobject * sha_info)279 sha_final(unsigned char digest[20], SHAobject *sha_info)
280 {
281     int count;
282     SHA_INT32 lo_bit_count, hi_bit_count;
283 
284     lo_bit_count = sha_info->count_lo;
285     hi_bit_count = sha_info->count_hi;
286     count = (int) ((lo_bit_count >> 3) & 0x3f);
287     ((SHA_BYTE *) sha_info->data)[count++] = 0x80;
288     if (count > SHA_BLOCKSIZE - 8) {
289         memset(((SHA_BYTE *) sha_info->data) + count, 0,
290                SHA_BLOCKSIZE - count);
291         sha_transform(sha_info);
292         memset((SHA_BYTE *) sha_info->data, 0, SHA_BLOCKSIZE - 8);
293     }
294     else {
295         memset(((SHA_BYTE *) sha_info->data) + count, 0,
296                SHA_BLOCKSIZE - 8 - count);
297     }
298 
299     /* GJS: note that we add the hi/lo in big-endian. sha_transform will
300        swap these values into host-order. */
301     sha_info->data[56] = (hi_bit_count >> 24) & 0xff;
302     sha_info->data[57] = (hi_bit_count >> 16) & 0xff;
303     sha_info->data[58] = (hi_bit_count >>  8) & 0xff;
304     sha_info->data[59] = (hi_bit_count >>  0) & 0xff;
305     sha_info->data[60] = (lo_bit_count >> 24) & 0xff;
306     sha_info->data[61] = (lo_bit_count >> 16) & 0xff;
307     sha_info->data[62] = (lo_bit_count >>  8) & 0xff;
308     sha_info->data[63] = (lo_bit_count >>  0) & 0xff;
309     sha_transform(sha_info);
310     digest[ 0] = (unsigned char) ((sha_info->digest[0] >> 24) & 0xff);
311     digest[ 1] = (unsigned char) ((sha_info->digest[0] >> 16) & 0xff);
312     digest[ 2] = (unsigned char) ((sha_info->digest[0] >>  8) & 0xff);
313     digest[ 3] = (unsigned char) ((sha_info->digest[0]      ) & 0xff);
314     digest[ 4] = (unsigned char) ((sha_info->digest[1] >> 24) & 0xff);
315     digest[ 5] = (unsigned char) ((sha_info->digest[1] >> 16) & 0xff);
316     digest[ 6] = (unsigned char) ((sha_info->digest[1] >>  8) & 0xff);
317     digest[ 7] = (unsigned char) ((sha_info->digest[1]      ) & 0xff);
318     digest[ 8] = (unsigned char) ((sha_info->digest[2] >> 24) & 0xff);
319     digest[ 9] = (unsigned char) ((sha_info->digest[2] >> 16) & 0xff);
320     digest[10] = (unsigned char) ((sha_info->digest[2] >>  8) & 0xff);
321     digest[11] = (unsigned char) ((sha_info->digest[2]      ) & 0xff);
322     digest[12] = (unsigned char) ((sha_info->digest[3] >> 24) & 0xff);
323     digest[13] = (unsigned char) ((sha_info->digest[3] >> 16) & 0xff);
324     digest[14] = (unsigned char) ((sha_info->digest[3] >>  8) & 0xff);
325     digest[15] = (unsigned char) ((sha_info->digest[3]      ) & 0xff);
326     digest[16] = (unsigned char) ((sha_info->digest[4] >> 24) & 0xff);
327     digest[17] = (unsigned char) ((sha_info->digest[4] >> 16) & 0xff);
328     digest[18] = (unsigned char) ((sha_info->digest[4] >>  8) & 0xff);
329     digest[19] = (unsigned char) ((sha_info->digest[4]      ) & 0xff);
330 }
331 
332 /*
333  * End of copied SHA code.
334  *
335  * ------------------------------------------------------------------------
336  */
337 
338 static PyTypeObject SHAtype;
339 
340 
341 static SHAobject *
newSHAobject(void)342 newSHAobject(void)
343 {
344     return (SHAobject *)PyObject_New(SHAobject, &SHAtype);
345 }
346 
347 /* Internal methods for a hashing object */
348 
349 static void
SHA_dealloc(PyObject * ptr)350 SHA_dealloc(PyObject *ptr)
351 {
352     PyObject_Del(ptr);
353 }
354 
355 
356 /* External methods for a hashing object */
357 
358 PyDoc_STRVAR(SHA_copy__doc__, "Return a copy of the hashing object.");
359 
360 static PyObject *
SHA_copy(SHAobject * self,PyObject * unused)361 SHA_copy(SHAobject *self, PyObject *unused)
362 {
363     SHAobject *newobj;
364 
365     if ( (newobj = newSHAobject())==NULL)
366         return NULL;
367 
368     SHAcopy(self, newobj);
369     return (PyObject *)newobj;
370 }
371 
372 PyDoc_STRVAR(SHA_digest__doc__,
373 "Return the digest value as a string of binary data.");
374 
375 static PyObject *
SHA_digest(SHAobject * self,PyObject * unused)376 SHA_digest(SHAobject *self, PyObject *unused)
377 {
378     unsigned char digest[SHA_DIGESTSIZE];
379     SHAobject temp;
380 
381     SHAcopy(self, &temp);
382     sha_final(digest, &temp);
383     return PyString_FromStringAndSize((const char *)digest, sizeof(digest));
384 }
385 
386 PyDoc_STRVAR(SHA_hexdigest__doc__,
387 "Return the digest value as a string of hexadecimal digits.");
388 
389 static PyObject *
SHA_hexdigest(SHAobject * self,PyObject * unused)390 SHA_hexdigest(SHAobject *self, PyObject *unused)
391 {
392     unsigned char digest[SHA_DIGESTSIZE];
393     SHAobject temp;
394     PyObject *retval;
395     char *hex_digest;
396     int i, j;
397 
398     /* Get the raw (binary) digest value */
399     SHAcopy(self, &temp);
400     sha_final(digest, &temp);
401 
402     /* Create a new string */
403     retval = PyString_FromStringAndSize(NULL, sizeof(digest) * 2);
404     if (!retval)
405             return NULL;
406     hex_digest = PyString_AsString(retval);
407     if (!hex_digest) {
408             Py_DECREF(retval);
409             return NULL;
410     }
411 
412     /* Make hex version of the digest */
413     for(i=j=0; i<sizeof(digest); i++) {
414         char c;
415         c = (digest[i] >> 4) & 0xf;
416         c = (c>9) ? c+'a'-10 : c + '0';
417         hex_digest[j++] = c;
418         c = (digest[i] & 0xf);
419         c = (c>9) ? c+'a'-10 : c + '0';
420         hex_digest[j++] = c;
421     }
422     return retval;
423 }
424 
425 PyDoc_STRVAR(SHA_update__doc__,
426 "Update this hashing object's state with the provided string.");
427 
428 static PyObject *
SHA_update(SHAobject * self,PyObject * args)429 SHA_update(SHAobject *self, PyObject *args)
430 {
431     Py_buffer view;
432     Py_ssize_t n;
433     unsigned char *buf;
434 
435     if (!PyArg_ParseTuple(args, "s*:update", &view))
436         return NULL;
437 
438     n = view.len;
439     buf = (unsigned char *) view.buf;
440     while (n > 0) {
441         Py_ssize_t nbytes;
442         if (n > INT_MAX)
443             nbytes = INT_MAX;
444         else
445             nbytes = n;
446         sha_update(self, buf,
447                    Py_SAFE_DOWNCAST(nbytes, Py_ssize_t, unsigned int));
448         buf += nbytes;
449         n -= nbytes;
450     }
451 
452     PyBuffer_Release(&view);
453     Py_RETURN_NONE;
454 }
455 
456 static PyMethodDef SHA_methods[] = {
457     {"copy",      (PyCFunction)SHA_copy,      METH_NOARGS,  SHA_copy__doc__},
458     {"digest",    (PyCFunction)SHA_digest,    METH_NOARGS,  SHA_digest__doc__},
459     {"hexdigest", (PyCFunction)SHA_hexdigest, METH_NOARGS,  SHA_hexdigest__doc__},
460     {"update",    (PyCFunction)SHA_update,    METH_VARARGS, SHA_update__doc__},
461     {NULL,        NULL}         /* sentinel */
462 };
463 
464 static PyObject *
SHA_get_block_size(PyObject * self,void * closure)465 SHA_get_block_size(PyObject *self, void *closure)
466 {
467     return PyInt_FromLong(SHA_BLOCKSIZE);
468 }
469 
470 static PyObject *
SHA_get_digest_size(PyObject * self,void * closure)471 SHA_get_digest_size(PyObject *self, void *closure)
472 {
473     return PyInt_FromLong(SHA_DIGESTSIZE);
474 }
475 
476 static PyObject *
SHA_get_name(PyObject * self,void * closure)477 SHA_get_name(PyObject *self, void *closure)
478 {
479     return PyString_FromStringAndSize("SHA1", 4);
480 }
481 
482 static PyGetSetDef SHA_getseters[] = {
483     {"digest_size",
484      (getter)SHA_get_digest_size, NULL,
485      NULL,
486      NULL},
487     {"block_size",
488      (getter)SHA_get_block_size, NULL,
489      NULL,
490      NULL},
491     {"name",
492      (getter)SHA_get_name, NULL,
493      NULL,
494      NULL},
495     /* the old md5 and sha modules support 'digest_size' as in PEP 247.
496      * the old sha module also supported 'digestsize'.  ugh. */
497     {"digestsize",
498      (getter)SHA_get_digest_size, NULL,
499      NULL,
500      NULL},
501     {NULL}  /* Sentinel */
502 };
503 
504 static PyTypeObject SHAtype = {
505     PyVarObject_HEAD_INIT(NULL, 0)
506     "_sha.sha",         /*tp_name*/
507     sizeof(SHAobject),  /*tp_size*/
508     0,                  /*tp_itemsize*/
509     /* methods */
510     SHA_dealloc,        /*tp_dealloc*/
511     0,                  /*tp_print*/
512     0,                  /*tp_getattr*/
513     0,                  /*tp_setattr*/
514     0,                  /*tp_compare*/
515     0,                  /*tp_repr*/
516     0,                  /*tp_as_number*/
517     0,                  /*tp_as_sequence*/
518     0,                  /*tp_as_mapping*/
519     0,                  /*tp_hash*/
520     0,                  /*tp_call*/
521     0,                  /*tp_str*/
522     0,                  /*tp_getattro*/
523     0,                  /*tp_setattro*/
524     0,                  /*tp_as_buffer*/
525     Py_TPFLAGS_DEFAULT, /*tp_flags*/
526     0,                  /*tp_doc*/
527     0,                  /*tp_traverse*/
528     0,                  /*tp_clear*/
529     0,                  /*tp_richcompare*/
530     0,                  /*tp_weaklistoffset*/
531     0,                  /*tp_iter*/
532     0,                  /*tp_iternext*/
533     SHA_methods,        /* tp_methods */
534     0,                  /* tp_members */
535     SHA_getseters,      /* tp_getset */
536 };
537 
538 
539 /* The single module-level function: new() */
540 
541 PyDoc_STRVAR(SHA_new__doc__,
542 "Return a new SHA hashing object.  An optional string argument\n\
543 may be provided; if present, this string will be automatically\n\
544 hashed.");
545 
546 static PyObject *
SHA_new(PyObject * self,PyObject * args,PyObject * kwdict)547 SHA_new(PyObject *self, PyObject *args, PyObject *kwdict)
548 {
549     static char *kwlist[] = {"string", NULL};
550     SHAobject *new;
551     Py_buffer view = { 0 };
552     Py_ssize_t n;
553     unsigned char *buf;
554 
555     if (!PyArg_ParseTupleAndKeywords(args, kwdict, "|s*:new", kwlist,
556                                      &view)) {
557         return NULL;
558     }
559 
560     if ((new = newSHAobject()) == NULL) {
561         PyBuffer_Release(&view);
562         return NULL;
563     }
564 
565     sha_init(new);
566 
567     if (PyErr_Occurred()) {
568         Py_DECREF(new);
569         PyBuffer_Release(&view);
570         return NULL;
571     }
572 
573     n = view.len;
574     buf = (unsigned char *) view.buf;
575     while (n > 0) {
576         Py_ssize_t nbytes;
577         if (n > INT_MAX)
578             nbytes = INT_MAX;
579         else
580             nbytes = n;
581         sha_update(new, buf,
582                    Py_SAFE_DOWNCAST(nbytes, Py_ssize_t, unsigned int));
583         buf += nbytes;
584         n -= nbytes;
585     }
586 
587     PyBuffer_Release(&view);
588 
589     return (PyObject *)new;
590 }
591 
592 
593 /* List of functions exported by this module */
594 
595 static struct PyMethodDef SHA_functions[] = {
596     {"new", (PyCFunction)SHA_new, METH_VARARGS|METH_KEYWORDS, SHA_new__doc__},
597     {NULL,      NULL}            /* Sentinel */
598 };
599 
600 
601 /* Initialize this module. */
602 
603 #define insint(n,v) { PyModule_AddIntConstant(m,n,v); }
604 
605 PyMODINIT_FUNC
init_sha(void)606 init_sha(void)
607 {
608     PyObject *m;
609 
610     Py_TYPE(&SHAtype) = &PyType_Type;
611     if (PyType_Ready(&SHAtype) < 0)
612         return;
613     m = Py_InitModule("_sha", SHA_functions);
614     if (m == NULL)
615         return;
616 
617     /* Add some symbolic constants to the module */
618     insint("blocksize", 1);  /* For future use, in case some hash
619                                 functions require an integral number of
620                                 blocks */
621     insint("digestsize", 20);
622     insint("digest_size", 20);
623 }
624