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1 /* SHA1 module */
2 
3 /* This module provides an interface to the SHA1 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    Trevor Perrin (trevp@trevp.net)
11 
12    Copyright (C) 2005-2007   Gregory P. Smith (greg@krypto.org)
13    Licensed to PSF under a Contributor Agreement.
14 
15 */
16 
17 /* SHA1 objects */
18 
19 #include "Python.h"
20 #include "hashlib.h"
21 #include "pystrhex.h"
22 
23 /*[clinic input]
24 module _sha1
25 class SHA1Type "SHA1object *" "&PyType_Type"
26 [clinic start generated code]*/
27 /*[clinic end generated code: output=da39a3ee5e6b4b0d input=3dc9a20d1becb759]*/
28 
29 /* Some useful types */
30 
31 #if SIZEOF_INT == 4
32 typedef unsigned int SHA1_INT32;        /* 32-bit integer */
33 typedef long long SHA1_INT64;        /* 64-bit integer */
34 #else
35 /* not defined. compilation will die. */
36 #endif
37 
38 /* The SHA1 block size and message digest sizes, in bytes */
39 
40 #define SHA1_BLOCKSIZE    64
41 #define SHA1_DIGESTSIZE   20
42 
43 /* The structure for storing SHA1 info */
44 
45 struct sha1_state {
46     SHA1_INT64 length;
47     SHA1_INT32 state[5], curlen;
48     unsigned char buf[SHA1_BLOCKSIZE];
49 };
50 
51 typedef struct {
52     PyObject_HEAD
53 
54     struct sha1_state hash_state;
55 } SHA1object;
56 
57 #include "clinic/sha1module.c.h"
58 
59 /* ------------------------------------------------------------------------
60  *
61  * This code for the SHA1 algorithm was noted as public domain. The
62  * original headers are pasted below.
63  *
64  * Several changes have been made to make it more compatible with the
65  * Python environment and desired interface.
66  *
67  */
68 
69 /* LibTomCrypt, modular cryptographic library -- Tom St Denis
70  *
71  * LibTomCrypt is a library that provides various cryptographic
72  * algorithms in a highly modular and flexible manner.
73  *
74  * The library is free for all purposes without any express
75  * guarantee it works.
76  *
77  * Tom St Denis, tomstdenis@gmail.com, https://www.libtom.net
78  */
79 
80 /* rotate the hard way (platform optimizations could be done) */
81 #define ROL(x, y) ( (((unsigned long)(x)<<(unsigned long)((y)&31)) | (((unsigned long)(x)&0xFFFFFFFFUL)>>(unsigned long)(32-((y)&31)))) & 0xFFFFFFFFUL)
82 #define ROLc(x, y) ( (((unsigned long)(x)<<(unsigned long)((y)&31)) | (((unsigned long)(x)&0xFFFFFFFFUL)>>(unsigned long)(32-((y)&31)))) & 0xFFFFFFFFUL)
83 
84 /* Endian Neutral macros that work on all platforms */
85 
86 #define STORE32H(x, y)                                                                     \
87      { (y)[0] = (unsigned char)(((x)>>24)&255); (y)[1] = (unsigned char)(((x)>>16)&255);   \
88        (y)[2] = (unsigned char)(((x)>>8)&255); (y)[3] = (unsigned char)((x)&255); }
89 
90 #define LOAD32H(x, y)                            \
91      { x = ((unsigned long)((y)[0] & 255)<<24) | \
92            ((unsigned long)((y)[1] & 255)<<16) | \
93            ((unsigned long)((y)[2] & 255)<<8)  | \
94            ((unsigned long)((y)[3] & 255)); }
95 
96 #define STORE64H(x, y)                                                                     \
97    { (y)[0] = (unsigned char)(((x)>>56)&255); (y)[1] = (unsigned char)(((x)>>48)&255);     \
98      (y)[2] = (unsigned char)(((x)>>40)&255); (y)[3] = (unsigned char)(((x)>>32)&255);     \
99      (y)[4] = (unsigned char)(((x)>>24)&255); (y)[5] = (unsigned char)(((x)>>16)&255);     \
100      (y)[6] = (unsigned char)(((x)>>8)&255); (y)[7] = (unsigned char)((x)&255); }
101 
102 
103 /* SHA1 macros */
104 
105 #define F0(x,y,z)  (z ^ (x & (y ^ z)))
106 #define F1(x,y,z)  (x ^ y ^ z)
107 #define F2(x,y,z)  ((x & y) | (z & (x | y)))
108 #define F3(x,y,z)  (x ^ y ^ z)
109 
sha1_compress(struct sha1_state * sha1,unsigned char * buf)110 static void sha1_compress(struct sha1_state *sha1, unsigned char *buf)
111 {
112     SHA1_INT32 a,b,c,d,e,W[80],i;
113 
114     /* copy the state into 512-bits into W[0..15] */
115     for (i = 0; i < 16; i++) {
116         LOAD32H(W[i], buf + (4*i));
117     }
118 
119     /* copy state */
120     a = sha1->state[0];
121     b = sha1->state[1];
122     c = sha1->state[2];
123     d = sha1->state[3];
124     e = sha1->state[4];
125 
126     /* expand it */
127     for (i = 16; i < 80; i++) {
128         W[i] = ROL(W[i-3] ^ W[i-8] ^ W[i-14] ^ W[i-16], 1);
129     }
130 
131     /* compress */
132     /* round one */
133     #define FF_0(a,b,c,d,e,i) e = (ROLc(a, 5) + F0(b,c,d) + e + W[i] + 0x5a827999UL); b = ROLc(b, 30);
134     #define FF_1(a,b,c,d,e,i) e = (ROLc(a, 5) + F1(b,c,d) + e + W[i] + 0x6ed9eba1UL); b = ROLc(b, 30);
135     #define FF_2(a,b,c,d,e,i) e = (ROLc(a, 5) + F2(b,c,d) + e + W[i] + 0x8f1bbcdcUL); b = ROLc(b, 30);
136     #define FF_3(a,b,c,d,e,i) e = (ROLc(a, 5) + F3(b,c,d) + e + W[i] + 0xca62c1d6UL); b = ROLc(b, 30);
137 
138     for (i = 0; i < 20; ) {
139        FF_0(a,b,c,d,e,i++);
140        FF_0(e,a,b,c,d,i++);
141        FF_0(d,e,a,b,c,i++);
142        FF_0(c,d,e,a,b,i++);
143        FF_0(b,c,d,e,a,i++);
144     }
145 
146     /* round two */
147     for (; i < 40; )  {
148        FF_1(a,b,c,d,e,i++);
149        FF_1(e,a,b,c,d,i++);
150        FF_1(d,e,a,b,c,i++);
151        FF_1(c,d,e,a,b,i++);
152        FF_1(b,c,d,e,a,i++);
153     }
154 
155     /* round three */
156     for (; i < 60; )  {
157        FF_2(a,b,c,d,e,i++);
158        FF_2(e,a,b,c,d,i++);
159        FF_2(d,e,a,b,c,i++);
160        FF_2(c,d,e,a,b,i++);
161        FF_2(b,c,d,e,a,i++);
162     }
163 
164     /* round four */
165     for (; i < 80; )  {
166        FF_3(a,b,c,d,e,i++);
167        FF_3(e,a,b,c,d,i++);
168        FF_3(d,e,a,b,c,i++);
169        FF_3(c,d,e,a,b,i++);
170        FF_3(b,c,d,e,a,i++);
171     }
172 
173     #undef FF_0
174     #undef FF_1
175     #undef FF_2
176     #undef FF_3
177 
178     /* store */
179     sha1->state[0] = sha1->state[0] + a;
180     sha1->state[1] = sha1->state[1] + b;
181     sha1->state[2] = sha1->state[2] + c;
182     sha1->state[3] = sha1->state[3] + d;
183     sha1->state[4] = sha1->state[4] + e;
184 }
185 
186 /**
187    Initialize the hash state
188    @param sha1   The hash state you wish to initialize
189 */
190 static void
sha1_init(struct sha1_state * sha1)191 sha1_init(struct sha1_state *sha1)
192 {
193    assert(sha1 != NULL);
194    sha1->state[0] = 0x67452301UL;
195    sha1->state[1] = 0xefcdab89UL;
196    sha1->state[2] = 0x98badcfeUL;
197    sha1->state[3] = 0x10325476UL;
198    sha1->state[4] = 0xc3d2e1f0UL;
199    sha1->curlen = 0;
200    sha1->length = 0;
201 }
202 
203 /**
204    Process a block of memory though the hash
205    @param sha1   The hash state
206    @param in     The data to hash
207    @param inlen  The length of the data (octets)
208 */
209 static void
sha1_process(struct sha1_state * sha1,const unsigned char * in,Py_ssize_t inlen)210 sha1_process(struct sha1_state *sha1,
211                   const unsigned char *in, Py_ssize_t inlen)
212 {
213     Py_ssize_t n;
214 
215     assert(sha1 != NULL);
216     assert(in != NULL);
217     assert(sha1->curlen <= sizeof(sha1->buf));
218 
219     while (inlen > 0) {
220         if (sha1->curlen == 0 && inlen >= SHA1_BLOCKSIZE) {
221            sha1_compress(sha1, (unsigned char *)in);
222            sha1->length   += SHA1_BLOCKSIZE * 8;
223            in             += SHA1_BLOCKSIZE;
224            inlen          -= SHA1_BLOCKSIZE;
225         } else {
226            n = Py_MIN(inlen, (Py_ssize_t)(SHA1_BLOCKSIZE - sha1->curlen));
227            memcpy(sha1->buf + sha1->curlen, in, (size_t)n);
228            sha1->curlen   += (SHA1_INT32)n;
229            in             += n;
230            inlen          -= n;
231            if (sha1->curlen == SHA1_BLOCKSIZE) {
232               sha1_compress(sha1, sha1->buf);
233               sha1->length += 8*SHA1_BLOCKSIZE;
234               sha1->curlen = 0;
235            }
236        }
237     }
238 }
239 
240 /**
241    Terminate the hash to get the digest
242    @param sha1  The hash state
243    @param out [out] The destination of the hash (20 bytes)
244 */
245 static void
sha1_done(struct sha1_state * sha1,unsigned char * out)246 sha1_done(struct sha1_state *sha1, unsigned char *out)
247 {
248     int i;
249 
250     assert(sha1 != NULL);
251     assert(out != NULL);
252     assert(sha1->curlen < sizeof(sha1->buf));
253 
254     /* increase the length of the message */
255     sha1->length += sha1->curlen * 8;
256 
257     /* append the '1' bit */
258     sha1->buf[sha1->curlen++] = (unsigned char)0x80;
259 
260     /* if the length is currently above 56 bytes we append zeros
261      * then compress.  Then we can fall back to padding zeros and length
262      * encoding like normal.
263      */
264     if (sha1->curlen > 56) {
265         while (sha1->curlen < 64) {
266             sha1->buf[sha1->curlen++] = (unsigned char)0;
267         }
268         sha1_compress(sha1, sha1->buf);
269         sha1->curlen = 0;
270     }
271 
272     /* pad up to 56 bytes of zeroes */
273     while (sha1->curlen < 56) {
274         sha1->buf[sha1->curlen++] = (unsigned char)0;
275     }
276 
277     /* store length */
278     STORE64H(sha1->length, sha1->buf+56);
279     sha1_compress(sha1, sha1->buf);
280 
281     /* copy output */
282     for (i = 0; i < 5; i++) {
283         STORE32H(sha1->state[i], out+(4*i));
284     }
285 }
286 
287 
288 /* .Source: /cvs/libtom/libtomcrypt/src/hashes/sha1.c,v $ */
289 /* .Revision: 1.10 $ */
290 /* .Date: 2007/05/12 14:25:28 $ */
291 
292 /*
293  * End of copied SHA1 code.
294  *
295  * ------------------------------------------------------------------------
296  */
297 
298 typedef struct {
299     PyTypeObject* sha1_type;
300 } SHA1State;
301 
302 static inline SHA1State*
sha1_get_state(PyObject * module)303 sha1_get_state(PyObject *module)
304 {
305     void *state = PyModule_GetState(module);
306     assert(state != NULL);
307     return (SHA1State *)state;
308 }
309 
310 static SHA1object *
newSHA1object(SHA1State * st)311 newSHA1object(SHA1State *st)
312 {
313     SHA1object *sha = (SHA1object *)PyObject_GC_New(SHA1object, st->sha1_type);
314     PyObject_GC_Track(sha);
315     return sha;
316 }
317 
318 
319 /* Internal methods for a hash object */
320 static int
SHA1_traverse(PyObject * ptr,visitproc visit,void * arg)321 SHA1_traverse(PyObject *ptr, visitproc visit, void *arg)
322 {
323     Py_VISIT(Py_TYPE(ptr));
324     return 0;
325 }
326 
327 static void
SHA1_dealloc(PyObject * ptr)328 SHA1_dealloc(PyObject *ptr)
329 {
330     PyTypeObject *tp = Py_TYPE(ptr);
331     PyObject_GC_UnTrack(ptr);
332     PyObject_GC_Del(ptr);
333     Py_DECREF(tp);
334 }
335 
336 
337 /* External methods for a hash object */
338 
339 /*[clinic input]
340 SHA1Type.copy
341 
342     cls: defining_class
343 
344 Return a copy of the hash object.
345 [clinic start generated code]*/
346 
347 static PyObject *
SHA1Type_copy_impl(SHA1object * self,PyTypeObject * cls)348 SHA1Type_copy_impl(SHA1object *self, PyTypeObject *cls)
349 /*[clinic end generated code: output=b32d4461ce8bc7a7 input=6c22e66fcc34c58e]*/
350 {
351     SHA1State *st = PyType_GetModuleState(cls);
352 
353     SHA1object *newobj;
354     if ((newobj = newSHA1object(st)) == NULL)
355         return NULL;
356 
357     newobj->hash_state = self->hash_state;
358     return (PyObject *)newobj;
359 }
360 
361 /*[clinic input]
362 SHA1Type.digest
363 
364 Return the digest value as a bytes object.
365 [clinic start generated code]*/
366 
367 static PyObject *
SHA1Type_digest_impl(SHA1object * self)368 SHA1Type_digest_impl(SHA1object *self)
369 /*[clinic end generated code: output=2f05302a7aa2b5cb input=13824b35407444bd]*/
370 {
371     unsigned char digest[SHA1_DIGESTSIZE];
372     struct sha1_state temp;
373 
374     temp = self->hash_state;
375     sha1_done(&temp, digest);
376     return PyBytes_FromStringAndSize((const char *)digest, SHA1_DIGESTSIZE);
377 }
378 
379 /*[clinic input]
380 SHA1Type.hexdigest
381 
382 Return the digest value as a string of hexadecimal digits.
383 [clinic start generated code]*/
384 
385 static PyObject *
SHA1Type_hexdigest_impl(SHA1object * self)386 SHA1Type_hexdigest_impl(SHA1object *self)
387 /*[clinic end generated code: output=4161fd71e68c6659 input=97691055c0c74ab0]*/
388 {
389     unsigned char digest[SHA1_DIGESTSIZE];
390     struct sha1_state temp;
391 
392     /* Get the raw (binary) digest value */
393     temp = self->hash_state;
394     sha1_done(&temp, digest);
395 
396     return _Py_strhex((const char *)digest, SHA1_DIGESTSIZE);
397 }
398 
399 /*[clinic input]
400 SHA1Type.update
401 
402     obj: object
403     /
404 
405 Update this hash object's state with the provided string.
406 [clinic start generated code]*/
407 
408 static PyObject *
SHA1Type_update(SHA1object * self,PyObject * obj)409 SHA1Type_update(SHA1object *self, PyObject *obj)
410 /*[clinic end generated code: output=d9902f0e5015e9ae input=aad8e07812edbba3]*/
411 {
412     Py_buffer buf;
413 
414     GET_BUFFER_VIEW_OR_ERROUT(obj, &buf);
415 
416     sha1_process(&self->hash_state, buf.buf, buf.len);
417 
418     PyBuffer_Release(&buf);
419     Py_RETURN_NONE;
420 }
421 
422 static PyMethodDef SHA1_methods[] = {
423     SHA1TYPE_COPY_METHODDEF
424     SHA1TYPE_DIGEST_METHODDEF
425     SHA1TYPE_HEXDIGEST_METHODDEF
426     SHA1TYPE_UPDATE_METHODDEF
427     {NULL,        NULL}         /* sentinel */
428 };
429 
430 static PyObject *
SHA1_get_block_size(PyObject * self,void * closure)431 SHA1_get_block_size(PyObject *self, void *closure)
432 {
433     return PyLong_FromLong(SHA1_BLOCKSIZE);
434 }
435 
436 static PyObject *
SHA1_get_name(PyObject * self,void * closure)437 SHA1_get_name(PyObject *self, void *closure)
438 {
439     return PyUnicode_FromStringAndSize("sha1", 4);
440 }
441 
442 static PyObject *
sha1_get_digest_size(PyObject * self,void * closure)443 sha1_get_digest_size(PyObject *self, void *closure)
444 {
445     return PyLong_FromLong(SHA1_DIGESTSIZE);
446 }
447 
448 static PyGetSetDef SHA1_getseters[] = {
449     {"block_size",
450      (getter)SHA1_get_block_size, NULL,
451      NULL,
452      NULL},
453     {"name",
454      (getter)SHA1_get_name, NULL,
455      NULL,
456      NULL},
457     {"digest_size",
458      (getter)sha1_get_digest_size, NULL,
459      NULL,
460      NULL},
461     {NULL}  /* Sentinel */
462 };
463 
464 static PyType_Slot sha1_type_slots[] = {
465     {Py_tp_dealloc, SHA1_dealloc},
466     {Py_tp_methods, SHA1_methods},
467     {Py_tp_getset, SHA1_getseters},
468     {Py_tp_traverse, SHA1_traverse},
469     {0,0}
470 };
471 
472 static PyType_Spec sha1_type_spec = {
473     .name = "_sha1.sha1",
474     .basicsize =  sizeof(SHA1object),
475     .flags = (Py_TPFLAGS_DEFAULT | Py_TPFLAGS_DISALLOW_INSTANTIATION |
476               Py_TPFLAGS_IMMUTABLETYPE | Py_TPFLAGS_HAVE_GC),
477     .slots = sha1_type_slots
478 };
479 
480 /* The single module-level function: new() */
481 
482 /*[clinic input]
483 _sha1.sha1
484 
485     string: object(c_default="NULL") = b''
486     *
487     usedforsecurity: bool = True
488 
489 Return a new SHA1 hash object; optionally initialized with a string.
490 [clinic start generated code]*/
491 
492 static PyObject *
_sha1_sha1_impl(PyObject * module,PyObject * string,int usedforsecurity)493 _sha1_sha1_impl(PyObject *module, PyObject *string, int usedforsecurity)
494 /*[clinic end generated code: output=6f8b3af05126e18e input=bd54b68e2bf36a8a]*/
495 {
496     SHA1object *new;
497     Py_buffer buf;
498 
499     if (string)
500         GET_BUFFER_VIEW_OR_ERROUT(string, &buf);
501 
502     SHA1State *st = sha1_get_state(module);
503     if ((new = newSHA1object(st)) == NULL) {
504         if (string)
505             PyBuffer_Release(&buf);
506         return NULL;
507     }
508 
509     sha1_init(&new->hash_state);
510 
511     if (PyErr_Occurred()) {
512         Py_DECREF(new);
513         if (string)
514             PyBuffer_Release(&buf);
515         return NULL;
516     }
517     if (string) {
518         sha1_process(&new->hash_state, buf.buf, buf.len);
519         PyBuffer_Release(&buf);
520     }
521 
522     return (PyObject *)new;
523 }
524 
525 
526 /* List of functions exported by this module */
527 
528 static struct PyMethodDef SHA1_functions[] = {
529     _SHA1_SHA1_METHODDEF
530     {NULL,      NULL}            /* Sentinel */
531 };
532 
533 static int
_sha1_traverse(PyObject * module,visitproc visit,void * arg)534 _sha1_traverse(PyObject *module, visitproc visit, void *arg)
535 {
536     SHA1State *state = sha1_get_state(module);
537     Py_VISIT(state->sha1_type);
538     return 0;
539 }
540 
541 static int
_sha1_clear(PyObject * module)542 _sha1_clear(PyObject *module)
543 {
544     SHA1State *state = sha1_get_state(module);
545     Py_CLEAR(state->sha1_type);
546     return 0;
547 }
548 
549 static void
_sha1_free(void * module)550 _sha1_free(void *module)
551 {
552     _sha1_clear((PyObject *)module);
553 }
554 
555 static int
_sha1_exec(PyObject * module)556 _sha1_exec(PyObject *module)
557 {
558     SHA1State* st = sha1_get_state(module);
559 
560     st->sha1_type = (PyTypeObject *)PyType_FromModuleAndSpec(
561         module, &sha1_type_spec, NULL);
562 
563     if (st->sha1_type == NULL) {
564         return -1;
565     }
566 
567     Py_INCREF(st->sha1_type);
568     if (PyModule_AddObject(module,
569                            "SHA1Type",
570                            (PyObject *)st->sha1_type) < 0) {
571         Py_DECREF(st->sha1_type);
572         return -1;
573     }
574 
575     return 0;
576 }
577 
578 
579 /* Initialize this module. */
580 
581 static PyModuleDef_Slot _sha1_slots[] = {
582     {Py_mod_exec, _sha1_exec},
583     {0, NULL}
584 };
585 
586 static struct PyModuleDef _sha1module = {
587         PyModuleDef_HEAD_INIT,
588         .m_name = "_sha1",
589         .m_size = sizeof(SHA1State),
590         .m_methods = SHA1_functions,
591         .m_slots = _sha1_slots,
592         .m_traverse = _sha1_traverse,
593         .m_clear = _sha1_clear,
594         .m_free = _sha1_free
595 };
596 
597 PyMODINIT_FUNC
PyInit__sha1(void)598 PyInit__sha1(void)
599 {
600     return PyModuleDef_Init(&_sha1module);
601 }
602