MagickCore  7.1.2-29
Convert, Edit, Or Compose Bitmap Images
signature.c
1 /*
2 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
3 % %
4 % %
5 % SSSSS IIIII GGGG N N AAA TTTTT U U RRRR EEEEE %
6 % SS I G NN N A A T U U R R E %
7 % SSS I G GG N N N AAAAA T U U RRRR EEE %
8 % SS I G G N NN A A T U U R R E %
9 % SSSSS IIIII GGG N N A A T UUU R R EEEEE %
10 % %
11 % %
12 % MagickCore Methods to Compute a Message Digest for an Image %
13 % %
14 % Software Design %
15 % Cristy %
16 % December 1992 %
17 % %
18 % %
19 % Copyright @ 1999 ImageMagick Studio LLC, a non-profit organization %
20 % dedicated to making software imaging solutions freely available. %
21 % %
22 % You may not use this file except in compliance with the License. You may %
23 % obtain a copy of the License at %
24 % %
25 % https://imagemagick.org/license/ %
26 % %
27 % Unless required by applicable law or agreed to in writing, software %
28 % distributed under the License is distributed on an "AS IS" BASIS, %
29 % WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. %
30 % See the License for the specific language governing permissions and %
31 % limitations under the License. %
32 % %
33 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
34 %
35 %
36 %
37 */
38 ␌
39 /*
40  Include declarations.
41 */
42 #include "MagickCore/studio.h"
43 #include "MagickCore/cache.h"
44 #include "MagickCore/exception.h"
45 #include "MagickCore/exception-private.h"
46 #include "MagickCore/property.h"
47 #include "MagickCore/image.h"
48 #include "MagickCore/memory_.h"
49 #include "MagickCore/memory-private.h"
50 #include "MagickCore/pixel-accessor.h"
51 #include "MagickCore/quantum.h"
52 #include "MagickCore/quantum-private.h"
53 #include "MagickCore/signature.h"
54 #include "MagickCore/signature-private.h"
55 #include "MagickCore/string_.h"
56 #include "MagickCore/timer-private.h"
57 /*
58  Define declarations.
59 */
60 #define SignatureBlocksize 64
61 #define SignatureDigestsize 32
62 ␌
63 /*
64  Typedef declarations.
65 */
66 struct _SignatureInfo
67 {
68  unsigned int
69  digestsize,
70  blocksize;
71 
72  StringInfo
73  *digest,
74  *message;
75 
76  unsigned int
77  *accumulator,
78  low_order,
79  high_order;
80 
81  size_t
82  extent;
83 
84  MagickBooleanType
85  lsb_first;
86 
87  time_t
88  timestamp;
89 
90  size_t
91  signature;
92 };
93 ␌
94 /*
95  Forward declarations.
96 */
97 static void
98  TransformSignature(SignatureInfo *);
99 ␌
100 /*
101 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
102 % %
103 % %
104 % %
105 + A c q u i r e S i g n a t u r e I n f o %
106 % %
107 % %
108 % %
109 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
110 %
111 % AcquireSignatureInfo() allocate the SignatureInfo structure.
112 %
113 % The format of the AcquireSignatureInfo method is:
114 %
115 % SignatureInfo *AcquireSignatureInfo(void)
116 %
117 */
118 MagickPrivate SignatureInfo *AcquireSignatureInfo(void)
119 {
120  SignatureInfo
121  *signature_info;
122 
123  signature_info=(SignatureInfo *) AcquireCriticalMemory(
124  sizeof(*signature_info));
125  (void) memset(signature_info,0,sizeof(*signature_info));
126  signature_info->digestsize=SignatureDigestsize;
127  signature_info->blocksize=SignatureBlocksize;
128  signature_info->digest=AcquireStringInfo(SignatureDigestsize);
129  signature_info->message=AcquireStringInfo(SignatureBlocksize);
130  signature_info->accumulator=(unsigned int *) AcquireQuantumMemory(
131  SignatureBlocksize,sizeof(*signature_info->accumulator));
132  if (signature_info->accumulator == (unsigned int *) NULL)
133  ThrowFatalException(ResourceLimitFatalError,"MemoryAllocationFailed");
134  (void) memset(signature_info->accumulator,0,SignatureBlocksize*
135  sizeof(*signature_info->accumulator));
136  signature_info->lsb_first=GetHostEndian() == LSBEndian ? MagickTrue :
137  MagickFalse;
138  signature_info->timestamp=GetMagickTime();
139  signature_info->signature=MagickCoreSignature;
140  InitializeSignature(signature_info);
141  return(signature_info);
142 }
143 ␌
144 /*
145 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
146 % %
147 % %
148 % %
149 + D e s t r o y S i g n a t u r e I n f o %
150 % %
151 % %
152 % %
153 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
154 %
155 % DestroySignatureInfo() zeros memory associated with the SignatureInfo
156 % structure.
157 %
158 % The format of the DestroySignatureInfo method is:
159 %
160 % SignatureInfo *DestroySignatureInfo(SignatureInfo *signature_info)
161 %
162 % A description of each parameter follows:
163 %
164 % o signature_info: the cipher signature_info.
165 %
166 */
167 MagickPrivate SignatureInfo *DestroySignatureInfo(SignatureInfo *signature_info)
168 {
169  assert(signature_info != (SignatureInfo *) NULL);
170  assert(signature_info->signature == MagickCoreSignature);
171  if (IsEventLogging() != MagickFalse)
172  (void) LogMagickEvent(TraceEvent,GetMagickModule(),"...");
173  if (signature_info->accumulator != (unsigned int *) NULL)
174  signature_info->accumulator=(unsigned int *) RelinquishMagickMemory(
175  signature_info->accumulator);
176  if (signature_info->message != (StringInfo *) NULL)
177  signature_info->message=DestroyStringInfo(signature_info->message);
178  if (signature_info->digest != (StringInfo *) NULL)
179  signature_info->digest=DestroyStringInfo(signature_info->digest);
180  signature_info->signature=(~MagickCoreSignature);
181  signature_info=(SignatureInfo *) RelinquishMagickMemory(signature_info);
182  return(signature_info);
183 }
184 ␌
185 /*
186 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
187 % %
188 % %
189 % %
190 + F i n a l i z e S i g n a t u r e %
191 % %
192 % %
193 % %
194 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
195 %
196 % FinalizeSignature() finalizes the Signature message accumulator computation.
197 %
198 % The format of the FinalizeSignature method is:
199 %
200 % FinalizeSignature(SignatureInfo *signature_info)
201 %
202 % A description of each parameter follows:
203 %
204 % o signature_info: the address of a structure of type SignatureInfo.
205 %
206 */
207 MagickPrivate void FinalizeSignature(SignatureInfo *signature_info)
208 {
209  ssize_t
210  i;
211 
212  unsigned char
213  *q;
214 
215  unsigned int
216  *p;
217 
218  size_t
219  extent;
220 
221  unsigned char
222  *datum;
223 
224  unsigned int
225  high_order,
226  low_order;
227 
228  /*
229  Add padding and return the message accumulator.
230  */
231  assert(signature_info != (SignatureInfo *) NULL);
232  assert(signature_info->signature == MagickCoreSignature);
233  if (IsEventLogging() != MagickFalse)
234  (void) LogMagickEvent(TraceEvent,GetMagickModule(),"...");
235  low_order=signature_info->low_order;
236  high_order=signature_info->high_order;
237  extent=((low_order >> 3) & 0x3f);
238  datum=GetStringInfoDatum(signature_info->message);
239  datum[extent++]=(unsigned char) 0x80;
240  if (extent <= (unsigned int) (GetStringInfoLength(signature_info->message)-8))
241  (void) memset(datum+extent,0,GetStringInfoLength(
242  signature_info->message)-8-extent);
243  else
244  {
245  (void) memset(datum+extent,0,GetStringInfoLength(
246  signature_info->message)-extent);
247  TransformSignature(signature_info);
248  (void) memset(datum,0,GetStringInfoLength(
249  signature_info->message)-8);
250  }
251  datum[56]=(unsigned char) (high_order >> 24);
252  datum[57]=(unsigned char) (high_order >> 16);
253  datum[58]=(unsigned char) (high_order >> 8);
254  datum[59]=(unsigned char) high_order;
255  datum[60]=(unsigned char) (low_order >> 24);
256  datum[61]=(unsigned char) (low_order >> 16);
257  datum[62]=(unsigned char) (low_order >> 8);
258  datum[63]=(unsigned char) low_order;
259  TransformSignature(signature_info);
260  p=signature_info->accumulator;
261  q=GetStringInfoDatum(signature_info->digest);
262  for (i=0; i < (SignatureDigestsize/4); i++)
263  {
264  *q++=(unsigned char) ((*p >> 24) & 0xff);
265  *q++=(unsigned char) ((*p >> 16) & 0xff);
266  *q++=(unsigned char) ((*p >> 8) & 0xff);
267  *q++=(unsigned char) (*p & 0xff);
268  p++;
269  }
270 }
271 ␌
272 /*
273 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
274 % %
275 % %
276 % %
277 + G e t S i g n a t u r e B l o c k s i z e %
278 % %
279 % %
280 % %
281 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
282 %
283 % GetSignatureBlocksize() returns the Signature blocksize.
284 %
285 % The format of the GetSignatureBlocksize method is:
286 %
287 % unsigned int *GetSignatureBlocksize(const SignatureInfo *signature_info)
288 %
289 % A description of each parameter follows:
290 %
291 % o signature_info: the signature info.
292 %
293 */
294 MagickPrivate unsigned int GetSignatureBlocksize(
295  const SignatureInfo *signature_info)
296 {
297  assert(signature_info != (SignatureInfo *) NULL);
298  assert(signature_info->signature == MagickCoreSignature);
299  if (IsEventLogging() != MagickFalse)
300  (void) LogMagickEvent(TraceEvent,GetMagickModule(),"...");
301  return(signature_info->blocksize);
302 }
303 ␌
304 /*
305 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
306 % %
307 % %
308 % %
309 + G e t S i g n a t u r e D i g e s t %
310 % %
311 % %
312 % %
313 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
314 %
315 % GetSignatureDigest() returns the signature digest.
316 %
317 % The format of the GetSignatureDigest method is:
318 %
319 % const StringInfo *GetSignatureDigest(const SignatureInfo *signature_info)
320 %
321 % A description of each parameter follows:
322 %
323 % o signature_info: the signature info.
324 %
325 */
326 MagickPrivate const StringInfo *GetSignatureDigest(
327  const SignatureInfo *signature_info)
328 {
329  assert(signature_info != (SignatureInfo *) NULL);
330  assert(signature_info->signature == MagickCoreSignature);
331  if (IsEventLogging() != MagickFalse)
332  (void) LogMagickEvent(TraceEvent,GetMagickModule(),"...");
333  return(signature_info->digest);
334 }
335 ␌
336 /*
337 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
338 % %
339 % %
340 % %
341 + G e t S i g n a t u r e D i g e s t s i z e %
342 % %
343 % %
344 % %
345 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
346 %
347 % GetSignatureDigestsize() returns the Signature digest size.
348 %
349 % The format of the GetSignatureDigestsize method is:
350 %
351 % unsigned int *GetSignatureDigestsize(const SignatureInfo *signature_info)
352 %
353 % A description of each parameter follows:
354 %
355 % o signature_info: the signature info.
356 %
357 */
358 MagickPrivate unsigned int GetSignatureDigestsize(
359  const SignatureInfo *signature_info)
360 {
361  assert(signature_info != (SignatureInfo *) NULL);
362  assert(signature_info->signature == MagickCoreSignature);
363  if (IsEventLogging() != MagickFalse)
364  (void) LogMagickEvent(TraceEvent,GetMagickModule(),"...");
365  return(signature_info->digestsize);
366 }
367 ␌
368 /*
369 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
370 % %
371 % %
372 % %
373 + I n i t i a l i z e S i g n a t u r e %
374 % %
375 % %
376 % %
377 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
378 %
379 % InitializeSignature() initializes the Signature accumulator.
380 %
381 % The format of the DestroySignatureInfo method is:
382 %
383 % void InitializeSignatureInfo(SignatureInfo *signature_info)
384 %
385 % A description of each parameter follows:
386 %
387 % o signature_info: the cipher signature_info.
388 %
389 */
390 MagickPrivate void InitializeSignature(SignatureInfo *signature_info)
391 {
392  assert(signature_info != (SignatureInfo *) NULL);
393  assert(signature_info->signature == MagickCoreSignature);
394  if (IsEventLogging() != MagickFalse)
395  (void) LogMagickEvent(TraceEvent,GetMagickModule(),"...");
396  signature_info->accumulator[0]=0x6a09e667U;
397  signature_info->accumulator[1]=0xbb67ae85U;
398  signature_info->accumulator[2]=0x3c6ef372U;
399  signature_info->accumulator[3]=0xa54ff53aU;
400  signature_info->accumulator[4]=0x510e527fU;
401  signature_info->accumulator[5]=0x9b05688cU;
402  signature_info->accumulator[6]=0x1f83d9abU;
403  signature_info->accumulator[7]=0x5be0cd19U;
404  signature_info->low_order=0;
405  signature_info->high_order=0;
406  signature_info->extent=0;
407 }
408 ␌
409 /*
410 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
411 % %
412 % %
413 % %
414 + S e t S i g n a t u r e D i g e s t %
415 % %
416 % %
417 % %
418 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
419 %
420 % SetSignatureDigest() set the signature digest.
421 %
422 % The format of the SetSignatureDigest method is:
423 %
424 % SetSignatureDigest(SignatureInfo *signature_info,
425 % const StringInfo *digest)
426 %
427 % A description of each parameter follows:
428 %
429 % o signature_info: the signature info.
430 %
431 % o digest: the digest.
432 %
433 */
434 MagickPrivate void SetSignatureDigest(SignatureInfo *signature_info,
435  const StringInfo *digest)
436 {
437  /*
438  Set the signature accumulator.
439  */
440  assert(signature_info != (SignatureInfo *) NULL);
441  assert(signature_info->signature == MagickCoreSignature);
442  SetStringInfo(signature_info->digest,digest);
443 }
444 ␌
445 /*
446 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
447 % %
448 % %
449 % %
450 % S i g n a t u r e I m a g e %
451 % %
452 % %
453 % %
454 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
455 %
456 % SignatureImage() computes a message digest from an image pixel stream with
457 % an implementation of the NIST SHA-256 Message Digest algorithm. This
458 % signature uniquely identifies the image and is convenient for determining
459 % if an image has been modified or whether two images are identical.
460 %
461 % The format of the SignatureImage method is:
462 %
463 % MagickBooleanType SignatureImage(Image *image,ExceptionInfo *exception)
464 %
465 % A description of each parameter follows:
466 %
467 % o image: the image.
468 %
469 % o exception: return any errors or warnings in this structure.
470 %
471 */
472 MagickExport MagickBooleanType SignatureImage(Image *image,
473  ExceptionInfo *exception)
474 {
475  CacheView
476  *image_view;
477 
478  char
479  *hex_signature;
480 
481  float
482  pixel;
483 
484  const Quantum
485  *p;
486 
487  SignatureInfo
488  *signature_info;
489 
490  ssize_t
491  y;
492 
493  StringInfo
494  *signature;
495 
496  unsigned char
497  *pixels;
498 
499  /*
500  Compute image digital signature.
501  */
502  assert(image != (Image *) NULL);
503  assert(image->signature == MagickCoreSignature);
504  if (IsEventLogging() != MagickFalse)
505  (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
506  signature_info=AcquireSignatureInfo();
507  signature=AcquireStringInfo(GetPixelChannels(image)*image->columns*
508  sizeof(pixel));
509  image_view=AcquireVirtualCacheView(image,exception);
510  for (y=0; y < (ssize_t) image->rows; y++)
511  {
512  ssize_t
513  x;
514 
515  unsigned char
516  *q;
517 
518  p=GetCacheViewVirtualPixels(image_view,0,y,image->columns,1,exception);
519  if (p == (const Quantum *) NULL)
520  break;
521  SetStringInfoLength(signature,GetPixelChannels(image)*image->columns*
522  sizeof(pixel));
523  pixels=GetStringInfoDatum(signature);
524  q=pixels;
525  for (x=0; x < (ssize_t) image->columns; x++)
526  {
527  ssize_t
528  i;
529 
530  if (GetPixelReadMask(image,p) <= (QuantumRange/2))
531  {
532  p+=(ptrdiff_t) GetPixelChannels(image);
533  continue;
534  }
535  for (i=0; i < (ssize_t) GetPixelChannels(image); i++)
536  {
537  ssize_t
538  j;
539 
540  PixelChannel channel = GetPixelChannelChannel(image,i);
541  PixelTrait traits = GetPixelChannelTraits(image,channel);
542  if ((traits & UpdatePixelTrait) == 0)
543  continue;
544  pixel=(float) (QuantumScale*(double) p[i]);
545  if (signature_info->lsb_first == MagickFalse)
546  for (j=(ssize_t) sizeof(pixel)-1; j >= 0; j--)
547  *q++=(unsigned char) ((unsigned char *) &pixel)[j];
548  else
549  for (j=0; j < (ssize_t) sizeof(pixel); j++)
550  *q++=(unsigned char) ((unsigned char *) &pixel)[j];
551  }
552  p+=(ptrdiff_t) GetPixelChannels(image);
553  }
554  SetStringInfoLength(signature,(size_t) (q-pixels));
555  UpdateSignature(signature_info,signature);
556  }
557  image_view=DestroyCacheView(image_view);
558  FinalizeSignature(signature_info);
559  hex_signature=StringInfoToHexString(GetSignatureDigest(signature_info));
560  (void) DeleteImageProperty(image,"signature");
561  (void) SetImageProperty(image,"signature",hex_signature,exception);
562  /*
563  Free resources.
564  */
565  hex_signature=DestroyString(hex_signature);
566  signature=DestroyStringInfo(signature);
567  signature_info=DestroySignatureInfo(signature_info);
568  return(MagickTrue);
569 }
570 ␌
571 /*
572 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
573 % %
574 % %
575 % %
576 + T r a n s f o r m S i g n a t u r e %
577 % %
578 % %
579 % %
580 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
581 %
582 % TransformSignature() transforms the Signature message accumulator.
583 %
584 % The format of the TransformSignature method is:
585 %
586 % TransformSignature(SignatureInfo *signature_info)
587 %
588 % A description of each parameter follows:
589 %
590 % o signature_info: the address of a structure of type SignatureInfo.
591 %
592 */
593 static void TransformSignature(SignatureInfo *signature_info)
594 {
595 #define Ch(x,y,z) (((x) & (y)) ^ (~(x) & (z)))
596 #define Maj(x,y,z) (((x) & (y)) ^ ((x) & (z)) ^ ((y) & (z)))
597 #define RotateRight(x,n) (Trunc32(((x) >> n) | ((x) << (32-n))))
598 #define Sigma0(x) (RotateRight(x,7) ^ RotateRight(x,18) ^ Trunc32((x) >> 3))
599 #define Sigma1(x) (RotateRight(x,17) ^ RotateRight(x,19) ^ Trunc32((x) >> 10))
600 #define Suma0(x) (RotateRight(x,2) ^ RotateRight(x,13) ^ RotateRight(x,22))
601 #define Suma1(x) (RotateRight(x,6) ^ RotateRight(x,11) ^ RotateRight(x,25))
602 #define Trunc32(x) ((unsigned int) ((x) & 0xffffffffU))
603 
604  ssize_t
605  i;
606 
607  unsigned char
608  *p;
609 
610  ssize_t
611  j;
612 
613  static const unsigned int
614  K[64] =
615  {
616  0x428a2f98U, 0x71374491U, 0xb5c0fbcfU, 0xe9b5dba5U, 0x3956c25bU,
617  0x59f111f1U, 0x923f82a4U, 0xab1c5ed5U, 0xd807aa98U, 0x12835b01U,
618  0x243185beU, 0x550c7dc3U, 0x72be5d74U, 0x80deb1feU, 0x9bdc06a7U,
619  0xc19bf174U, 0xe49b69c1U, 0xefbe4786U, 0x0fc19dc6U, 0x240ca1ccU,
620  0x2de92c6fU, 0x4a7484aaU, 0x5cb0a9dcU, 0x76f988daU, 0x983e5152U,
621  0xa831c66dU, 0xb00327c8U, 0xbf597fc7U, 0xc6e00bf3U, 0xd5a79147U,
622  0x06ca6351U, 0x14292967U, 0x27b70a85U, 0x2e1b2138U, 0x4d2c6dfcU,
623  0x53380d13U, 0x650a7354U, 0x766a0abbU, 0x81c2c92eU, 0x92722c85U,
624  0xa2bfe8a1U, 0xa81a664bU, 0xc24b8b70U, 0xc76c51a3U, 0xd192e819U,
625  0xd6990624U, 0xf40e3585U, 0x106aa070U, 0x19a4c116U, 0x1e376c08U,
626  0x2748774cU, 0x34b0bcb5U, 0x391c0cb3U, 0x4ed8aa4aU, 0x5b9cca4fU,
627  0x682e6ff3U, 0x748f82eeU, 0x78a5636fU, 0x84c87814U, 0x8cc70208U,
628  0x90befffaU, 0xa4506cebU, 0xbef9a3f7U, 0xc67178f2U
629  }; /* 32-bit fractional part of the cube root of the first 64 primes */
630 
631  unsigned int
632  A = 0,
633  B,
634  C,
635  D,
636  E,
637  F,
638  G,
639  H,
640  shift,
641  T,
642  T1,
643  T2,
644  W[64];
645 
646  shift=32;
647  p=GetStringInfoDatum(signature_info->message);
648  if (signature_info->lsb_first == MagickFalse)
649  {
650 DisableMSCWarning(4127)
651  if (sizeof(unsigned int) <= 4)
652 RestoreMSCWarning
653  for (i=0; i < 16; i++)
654  {
655  T=(*((unsigned int *) p));
656  p+=(ptrdiff_t) 4;
657  W[i]=Trunc32(T);
658  }
659  else
660  for (i=0; i < 16; i+=2)
661  {
662  T=(*((unsigned int *) p));
663  p+=(ptrdiff_t) 8;
664  W[i]=Trunc32(T >> shift);
665  W[i+1]=Trunc32(T);
666  }
667  }
668  else
669 DisableMSCWarning(4127)
670  if (sizeof(unsigned int) <= 4)
671 RestoreMSCWarning
672  for (i=0; i < 16; i++)
673  {
674  T=(*((unsigned int *) p));
675  p+=(ptrdiff_t) 4;
676  W[i]=((T << 24) & 0xff000000) | ((T << 8) & 0x00ff0000) |
677  ((T >> 8) & 0x0000ff00) | ((T >> 24) & 0x000000ff);
678  }
679  else
680  for (i=0; i < 16; i+=2)
681  {
682  T=(*((unsigned int *) p));
683  p+=(ptrdiff_t) 8;
684  W[i]=((T << 24) & 0xff000000) | ((T << 8) & 0x00ff0000) |
685  ((T >> 8) & 0x0000ff00) | ((T >> 24) & 0x000000ff);
686  T>>=shift;
687  W[i+1]=((T << 24) & 0xff000000) | ((T << 8) & 0x00ff0000) |
688  ((T >> 8) & 0x0000ff00) | ((T >> 24) & 0x000000ff);
689  }
690  /*
691  Copy accumulator to registers.
692  */
693  A=signature_info->accumulator[0];
694  B=signature_info->accumulator[1];
695  C=signature_info->accumulator[2];
696  D=signature_info->accumulator[3];
697  E=signature_info->accumulator[4];
698  F=signature_info->accumulator[5];
699  G=signature_info->accumulator[6];
700  H=signature_info->accumulator[7];
701  for (i=16; i < 64; i++)
702  W[i]=Trunc32(Sigma1(W[i-2])+W[i-7]+Sigma0(W[i-15])+W[i-16]);
703  for (j=0; j < 64; j++)
704  {
705  T1=Trunc32(H+Suma1(E)+Ch(E,F,G)+K[j]+W[j]);
706  T2=Trunc32(Suma0(A)+Maj(A,B,C));
707  H=G;
708  G=F;
709  F=E;
710  E=Trunc32(D+T1);
711  D=C;
712  C=B;
713  B=A;
714  A=Trunc32(T1+T2);
715  }
716  /*
717  Add registers back to accumulator.
718  */
719  signature_info->accumulator[0]=Trunc32(signature_info->accumulator[0]+A);
720  signature_info->accumulator[1]=Trunc32(signature_info->accumulator[1]+B);
721  signature_info->accumulator[2]=Trunc32(signature_info->accumulator[2]+C);
722  signature_info->accumulator[3]=Trunc32(signature_info->accumulator[3]+D);
723  signature_info->accumulator[4]=Trunc32(signature_info->accumulator[4]+E);
724  signature_info->accumulator[5]=Trunc32(signature_info->accumulator[5]+F);
725  signature_info->accumulator[6]=Trunc32(signature_info->accumulator[6]+G);
726  signature_info->accumulator[7]=Trunc32(signature_info->accumulator[7]+H);
727  /*
728  Reset working registers.
729  */
730  A=0;
731  B=0;
732  C=0;
733  D=0;
734  E=0;
735  F=0;
736  G=0;
737  H=0;
738  T=0;
739  T1=0;
740  T2=0;
741  (void) ResetMagickMemory(W,0,sizeof(W));
742 }
743 ␌
744 /*
745 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
746 % %
747 % %
748 % %
749 + U p d a t e S i g n a t u r e %
750 % %
751 % %
752 % %
753 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
754 %
755 % UpdateSignature() updates the Signature message accumulator.
756 %
757 % The format of the UpdateSignature method is:
758 %
759 % UpdateSignature(SignatureInfo *signature_info,const StringInfo *message)
760 %
761 % A description of each parameter follows:
762 %
763 % o signature_info: the address of a structure of type SignatureInfo.
764 %
765 % o message: the message.
766 %
767 */
768 MagickPrivate void UpdateSignature(SignatureInfo *signature_info,
769  const StringInfo *message)
770 {
771  size_t
772  i;
773 
774  unsigned char
775  *p;
776 
777  size_t
778  n;
779 
780  unsigned int
781  length;
782 
783  /*
784  Update the Signature accumulator.
785  */
786  assert(signature_info != (SignatureInfo *) NULL);
787  assert(signature_info->signature == MagickCoreSignature);
788  n=GetStringInfoLength(message);
789  length=Trunc32((unsigned int) (signature_info->low_order+(n << 3)));
790  if (length < signature_info->low_order)
791  signature_info->high_order++;
792  signature_info->low_order=length;
793  signature_info->high_order+=(unsigned int) n >> 29;
794  p=GetStringInfoDatum(message);
795  if (signature_info->extent != 0)
796  {
797  i=GetStringInfoLength(signature_info->message)-signature_info->extent;
798  if (i > n)
799  i=n;
800  (void) memcpy(GetStringInfoDatum(signature_info->message)+
801  signature_info->extent,p,i);
802  n-=i;
803  p+=(ptrdiff_t) i;
804  signature_info->extent+=i;
805  if (signature_info->extent != GetStringInfoLength(signature_info->message))
806  return;
807  TransformSignature(signature_info);
808  }
809  while (n >= GetStringInfoLength(signature_info->message))
810  {
811  SetStringInfoDatum(signature_info->message,p);
812  p+=(ptrdiff_t) GetStringInfoLength(signature_info->message);
813  n-=GetStringInfoLength(signature_info->message);
814  TransformSignature(signature_info);
815  }
816  (void) memcpy(GetStringInfoDatum(signature_info->message),p,n);
817  signature_info->extent=n;
818 }
_CacheView
Definition: cache-view.c:66
_ExceptionInfo
Definition: exception.h:102
_Image
Definition: image.h:132
_SignatureInfo
Definition: signature.c:67
_StringInfo
Definition: string_.h:28