granicus.if.org Git - imagemagick/blob - MagickCore/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 %                               John Cristy                                   %
  16 %                              December 1992                                  %
  17 %                                                                             %
  18 %                                                                             %
  19 %  Copyright 1999-2012 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 %    http://www.imagemagick.org/script/license.php                            %
  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 \f
  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/pixel-accessor.h"
  50 #include "MagickCore/quantum.h"
  51 #include "MagickCore/quantum-private.h"
  52 #include "MagickCore/signature.h"
  53 #include "MagickCore/signature-private.h"
  54 #include "MagickCore/string_.h"
  55 /*
  56   Define declarations.
  57 */
  58 #define SignatureBlocksize  64
  59 #define SignatureDigestsize  32
  60 \f
  61 /*
  62   Typedef declarations.
  63 */
  64 struct _SignatureInfo
  65 {
  66   unsigned int
  67     digestsize,
  68     blocksize;
  69
  70   StringInfo
  71     *digest,
  72     *message;
  73
  74   unsigned int
  75     *accumulator,
  76     low_order,
  77     high_order;
  78
  79   size_t
  80     offset;
  81
  82   MagickBooleanType
  83     lsb_first;
  84
  85   ssize_t
  86     timestamp;
  87
  88   size_t
  89     signature;
  90 };
  91 \f
  92 /*
  93   Forward declarations.
  94 */
  95 static void
  96   TransformSignature(SignatureInfo *);
  97 \f
  98 /*
  99 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 100 %                                                                             %
 101 %                                                                             %
 102 %                                                                             %
 103 +   A c q u i r e S i g n a t u r e I n f o                                   %
 104 %                                                                             %
 105 %                                                                             %
 106 %                                                                             %
 107 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 108 %
 109 %  AcquireSignatureInfo() allocate the SignatureInfo structure.
 110 %
 111 %  The format of the AcquireSignatureInfo method is:
 112 %
 113 %      SignatureInfo *AcquireSignatureInfo(void)
 114 %
 115 */
 116 MagickPrivate SignatureInfo *AcquireSignatureInfo(void)
 117 {
 118   SignatureInfo
 119     *signature_info;
 120
 121   unsigned int
 122     lsb_first;
 123
 124   signature_info=(SignatureInfo *) AcquireMagickMemory(sizeof(*signature_info));
 125   if (signature_info == (SignatureInfo *) NULL)
 126     ThrowFatalException(ResourceLimitFatalError,"MemoryAllocationFailed");
 127   (void) ResetMagickMemory(signature_info,0,sizeof(*signature_info));
 128   signature_info->digestsize=SignatureDigestsize;
 129   signature_info->blocksize=SignatureBlocksize;
 130   signature_info->digest=AcquireStringInfo(SignatureDigestsize);
 131   signature_info->message=AcquireStringInfo(SignatureBlocksize);
 132   signature_info->accumulator=(unsigned int *) AcquireQuantumMemory(
 133     SignatureBlocksize,sizeof(*signature_info->accumulator));
 134   if (signature_info->accumulator == (unsigned int *) NULL)
 135     ThrowFatalException(ResourceLimitFatalError,"MemoryAllocationFailed");
 136   lsb_first=1;
 137   signature_info->lsb_first=(int) (*(char *) &lsb_first) == 1 ? MagickTrue :
 138     MagickFalse;
 139   signature_info->timestamp=(ssize_t) time(0);
 140   signature_info->signature=MagickSignature;
 141   InitializeSignature(signature_info);
 142   return(signature_info);
 143 }
 144 \f
 145 /*
 146 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 147 %                                                                             %
 148 %                                                                             %
 149 %                                                                             %
 150 +   D e s t r o y S i g n a t u r e I n f o                                   %
 151 %                                                                             %
 152 %                                                                             %
 153 %                                                                             %
 154 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 155 %
 156 %  DestroySignatureInfo() zeros memory associated with the SignatureInfo
 157 %  structure.
 158 %
 159 %  The format of the DestroySignatureInfo method is:
 160 %
 161 %      SignatureInfo *DestroySignatureInfo(SignatureInfo *signature_info)
 162 %
 163 %  A description of each parameter follows:
 164 %
 165 %    o signature_info: the cipher signature_info.
 166 %
 167 */
 168 MagickPrivate SignatureInfo *DestroySignatureInfo(SignatureInfo *signature_info)
 169 {
 170   (void) LogMagickEvent(TraceEvent,GetMagickModule(),"...");
 171   assert(signature_info != (SignatureInfo *) NULL);
 172   assert(signature_info->signature == MagickSignature);
 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=(~MagickSignature);
 181   signature_info=(SignatureInfo *) RelinquishMagickMemory(signature_info);
 182   return(signature_info);
 183 }
 184 \f
 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   register ssize_t
 210     i;
 211
 212   register unsigned char
 213     *q;
 214
 215   register unsigned int
 216     *p;
 217
 218   unsigned char
 219     *datum;
 220
 221   unsigned int
 222     count,
 223     high_order,
 224     low_order;
 225
 226   /*
 227     Add padding and return the message accumulator.
 228   */
 229   (void) LogMagickEvent(TraceEvent,GetMagickModule(),"...");
 230   assert(signature_info != (SignatureInfo *) NULL);
 231   assert(signature_info->signature == MagickSignature);
 232   low_order=signature_info->low_order;
 233   high_order=signature_info->high_order;
 234   count=((low_order >> 3) & 0x3f);
 235   datum=GetStringInfoDatum(signature_info->message);
 236   datum[count++]=(unsigned char) 0x80;
 237   if (count <= (unsigned int) (GetStringInfoLength(signature_info->message)-8))
 238     (void) ResetMagickMemory(datum+count,0,GetStringInfoLength(
 239       signature_info->message)-8-count);
 240   else
 241     {
 242       (void) ResetMagickMemory(datum+count,0,GetStringInfoLength(
 243         signature_info->message)-count);
 244       TransformSignature(signature_info);
 245       (void) ResetMagickMemory(datum,0,GetStringInfoLength(
 246         signature_info->message)-8);
 247     }
 248   datum[56]=(unsigned char) (high_order >> 24);
 249   datum[57]=(unsigned char) (high_order >> 16);
 250   datum[58]=(unsigned char) (high_order >> 8);
 251   datum[59]=(unsigned char) high_order;
 252   datum[60]=(unsigned char) (low_order >> 24);
 253   datum[61]=(unsigned char) (low_order >> 16);
 254   datum[62]=(unsigned char) (low_order >> 8);
 255   datum[63]=(unsigned char) low_order;
 256   TransformSignature(signature_info);
 257   p=signature_info->accumulator;
 258   q=GetStringInfoDatum(signature_info->digest);
 259   for (i=0; i < (SignatureDigestsize/4); i++)
 260   {
 261     *q++=(unsigned char) ((*p >> 24) & 0xff);
 262     *q++=(unsigned char) ((*p >> 16) & 0xff);
 263     *q++=(unsigned char) ((*p >> 8) & 0xff);
 264     *q++=(unsigned char) (*p & 0xff);
 265     p++;
 266   }
 267   /*
 268     Reset working registers.
 269   */
 270   count=0;
 271   high_order=0;
 272   low_order=0;
 273 }
 274 \f
 275 /*
 276 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 277 %                                                                             %
 278 %                                                                             %
 279 %                                                                             %
 280 +   G e t S i g n a t u r e B l o c k s i z e                                 %
 281 %                                                                             %
 282 %                                                                             %
 283 %                                                                             %
 284 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 285 %
 286 %  GetSignatureBlocksize() returns the Signature blocksize.
 287 %
 288 %  The format of the GetSignatureBlocksize method is:
 289 %
 290 %      unsigned int *GetSignatureBlocksize(const SignatureInfo *signature_info)
 291 %
 292 %  A description of each parameter follows:
 293 %
 294 %    o signature_info: the signature info.
 295 %
 296 */
 297 MagickPrivate unsigned int GetSignatureBlocksize(
 298   const SignatureInfo *signature_info)
 299 {
 300   (void) LogMagickEvent(TraceEvent,GetMagickModule(),"...");
 301   assert(signature_info != (SignatureInfo *) NULL);
 302   assert(signature_info->signature == MagickSignature);
 303   return(signature_info->blocksize);
 304 }
 305 \f
 306 /*
 307 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 308 %                                                                             %
 309 %                                                                             %
 310 %                                                                             %
 311 +   G e t S i g n a t u r e D i g e s t                                       %
 312 %                                                                             %
 313 %                                                                             %
 314 %                                                                             %
 315 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 316 %
 317 %  GetSignatureDigest() returns the signature digest.
 318 %
 319 %  The format of the GetSignatureDigest method is:
 320 %
 321 %      const StringInfo *GetSignatureDigest(const SignatureInfo *signature_info)
 322 %
 323 %  A description of each parameter follows:
 324 %
 325 %    o signature_info: the signature info.
 326 %
 327 */
 328 MagickPrivate const StringInfo *GetSignatureDigest(
 329   const SignatureInfo *signature_info)
 330 {
 331   (void) LogMagickEvent(TraceEvent,GetMagickModule(),"...");
 332   assert(signature_info != (SignatureInfo *) NULL);
 333   assert(signature_info->signature == MagickSignature);
 334   return(signature_info->digest);
 335 }
 336 \f
 337 /*
 338 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 339 %                                                                             %
 340 %                                                                             %
 341 %                                                                             %
 342 +   G e t S i g n a t u r e D i g e s t s i z e                               %
 343 %                                                                             %
 344 %                                                                             %
 345 %                                                                             %
 346 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 347 %
 348 %  GetSignatureDigestsize() returns the Signature digest size.
 349 %
 350 %  The format of the GetSignatureDigestsize method is:
 351 %
 352 %      unsigned int *GetSignatureDigestsize(const SignatureInfo *signature_info)
 353 %
 354 %  A description of each parameter follows:
 355 %
 356 %    o signature_info: the signature info.
 357 %
 358 */
 359 MagickPrivate unsigned int GetSignatureDigestsize(
 360   const SignatureInfo *signature_info)
 361 {
 362   (void) LogMagickEvent(TraceEvent,GetMagickModule(),"...");
 363   assert(signature_info != (SignatureInfo *) NULL);
 364   assert(signature_info->signature == MagickSignature);
 365   return(signature_info->digestsize);
 366 }
 367 \f
 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   (void) LogMagickEvent(TraceEvent,GetMagickModule(),"...");
 393   assert(signature_info != (SignatureInfo *) NULL);
 394   assert(signature_info->signature == MagickSignature);
 395   signature_info->accumulator[0]=0x6a09e667U;
 396   signature_info->accumulator[1]=0xbb67ae85U;
 397   signature_info->accumulator[2]=0x3c6ef372U;
 398   signature_info->accumulator[3]=0xa54ff53aU;
 399   signature_info->accumulator[4]=0x510e527fU;
 400   signature_info->accumulator[5]=0x9b05688cU;
 401   signature_info->accumulator[6]=0x1f83d9abU;
 402   signature_info->accumulator[7]=0x5be0cd19U;
 403   signature_info->low_order=0;
 404   signature_info->high_order=0;
 405   signature_info->offset=0;
 406 }
 407 \f
 408 /*
 409 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 410 %                                                                             %
 411 %                                                                             %
 412 %                                                                             %
 413 +   S e t S i g n a t u r e D i g e s t                                       %
 414 %                                                                             %
 415 %                                                                             %
 416 %                                                                             %
 417 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 418 %
 419 %  SetSignatureDigest() set the signature digest.
 420 %
 421 %  The format of the SetSignatureDigest method is:
 422 %
 423 %      SetSignatureDigest(SignatureInfo *signature_info,
 424 %        const StringInfo *digest)
 425 %
 426 %  A description of each parameter follows:
 427 %
 428 %    o signature_info: the signature info.
 429 %
 430 %    o digest: the digest.
 431 %
 432 */
 433 MagickPrivate void SetSignatureDigest(SignatureInfo *signature_info,
 434   const StringInfo *digest)
 435 {
 436   /*
 437     Set the signature accumulator.
 438   */
 439   assert(signature_info != (SignatureInfo *) NULL);
 440   assert(signature_info->signature == MagickSignature);
 441   SetStringInfo(signature_info->digest,digest);
 442 }
 443 \f
 444 /*
 445 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 446 %                                                                             %
 447 %                                                                             %
 448 %                                                                             %
 449 %   S i g n a t u r e I m a g e                                               %
 450 %                                                                             %
 451 %                                                                             %
 452 %                                                                             %
 453 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 454 %
 455 %  SignatureImage() computes a message digest from an image pixel stream with
 456 %  an implementation of the NIST SHA-256 Message Digest algorithm.  This
 457 %  signature uniquely identifies the image and is convenient for determining
 458 %  if an image has been modified or whether two images are identical.
 459 %
 460 %  The format of the SignatureImage method is:
 461 %
 462 %      MagickBooleanType SignatureImage(Image *image,ExceptionInfo *exception)
 463 %
 464 %  A description of each parameter follows:
 465 %
 466 %    o image: the image.
 467 %
 468 %    o exception: return any errors or warnings in this structure.
 469 %
 470 */
 471 MagickExport MagickBooleanType SignatureImage(Image *image,
 472   ExceptionInfo *exception)
 473 {
 474   CacheView
 475     *image_view;
 476
 477   char
 478     *hex_signature;
 479
 480   double
 481     pixel;
 482
 483   register const Quantum
 484     *p;
 485
 486   SignatureInfo
 487     *signature_info;
 488
 489   ssize_t
 490     y;
 491
 492   StringInfo
 493     *signature;
 494
 495   unsigned char
 496     *pixels;
 497
 498   /*
 499     Compute image digital signature.
 500   */
 501   assert(image != (Image *) NULL);
 502   assert(image->signature == MagickSignature);
 503   if (image->debug != MagickFalse)
 504     (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
 505   signature_info=AcquireSignatureInfo();
 506   signature=AcquireStringInfo(image->columns*GetPixelChannels(image)*
 507     sizeof(pixel));
 508   pixels=GetStringInfoDatum(signature);
 509   image_view=AcquireCacheView(image);
 510   for (y=0; y < (ssize_t) image->rows; y++)
 511   {
 512     register ssize_t
 513       x;
 514
 515     register 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     q=pixels;
 522     for (x=0; x < (ssize_t) image->columns; x++)
 523     {
 524       register ssize_t
 525         i;
 526
 527       for (i=0; i < (ssize_t) GetPixelChannels(image); i++)
 528       {
 529         PixelChannel
 530           channel;
 531
 532         PixelTrait
 533           traits;
 534
 535         register ssize_t
 536           j;
 537
 538         channel=GetPixelChannelMapChannel(image,i);
 539         traits=GetPixelChannelMapTraits(image,channel);
 540         if (traits == UndefinedPixelTrait)
 541           continue;
 542         if ((traits & UpdatePixelTrait) == 0)
 543           continue;
 544         pixel=QuantumScale*p[i];
 545         for (j=0; j < (ssize_t) sizeof(pixel); j++)
 546           *q++=(unsigned char) (&pixel)[j];
 547       }
 548       p+=GetPixelChannels(image);
 549     }
 550     SetStringInfoLength(signature,(size_t) (q-pixels));
 551     UpdateSignature(signature_info,signature);
 552   }
 553   image_view=DestroyCacheView(image_view);
 554   FinalizeSignature(signature_info);
 555   hex_signature=StringInfoToHexString(GetSignatureDigest(signature_info));
 556   (void) DeleteImageProperty(image,"signature");
 557   (void) SetImageProperty(image,"signature",hex_signature,exception);
 558   /*
 559     Free resources.
 560   */
 561   hex_signature=DestroyString(hex_signature);
 562   signature=DestroyStringInfo(signature);
 563   signature_info=DestroySignatureInfo(signature_info);
 564   return(MagickTrue);
 565 }
 566 \f
 567 /*
 568 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 569 %                                                                             %
 570 %                                                                             %
 571 %                                                                             %
 572 +   T r a n s f o r m S i g n a t u r e                                       %
 573 %                                                                             %
 574 %                                                                             %
 575 %                                                                             %
 576 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 577 %
 578 %  TransformSignature() transforms the Signature message accumulator.
 579 %
 580 %  The format of the TransformSignature method is:
 581 %
 582 %      TransformSignature(SignatureInfo *signature_info)
 583 %
 584 %  A description of each parameter follows:
 585 %
 586 %    o signature_info: the address of a structure of type SignatureInfo.
 587 %
 588 */
 589
 590 static inline unsigned int Ch(unsigned int x,unsigned int y,unsigned int z)
 591 {
 592   return((x & y) ^ (~x & z));
 593 }
 594
 595 static inline unsigned int Maj(unsigned int x,unsigned int y,unsigned int z)
 596 {
 597   return((x & y) ^ (x & z) ^ (y & z));
 598 }
 599
 600 static inline unsigned int Trunc32(unsigned int x)
 601 {
 602   return((unsigned int) (x & 0xffffffffU));
 603 }
 604
 605 static unsigned int RotateRight(unsigned int x,unsigned int n)
 606 {
 607   return(Trunc32((x >> n) | (x << (32-n))));
 608 }
 609
 610 static void TransformSignature(SignatureInfo *signature_info)
 611 {
 612 #define Sigma0(x)  (RotateRight(x,7) ^ RotateRight(x,18) ^ Trunc32((x) >> 3))
 613 #define Sigma1(x)  (RotateRight(x,17) ^ RotateRight(x,19) ^ Trunc32((x) >> 10))
 614 #define Suma0(x)  (RotateRight(x,2) ^ RotateRight(x,13) ^ RotateRight(x,22))
 615 #define Suma1(x)  (RotateRight(x,6) ^ RotateRight(x,11) ^ RotateRight(x,25))
 616
 617   register ssize_t
 618     i;
 619
 620   register unsigned char
 621     *p;
 622
 623   ssize_t
 624     j;
 625
 626   static unsigned int
 627     K[64] =
 628     {
 629       0x428a2f98U, 0x71374491U, 0xb5c0fbcfU, 0xe9b5dba5U, 0x3956c25bU,
 630       0x59f111f1U, 0x923f82a4U, 0xab1c5ed5U, 0xd807aa98U, 0x12835b01U,
 631       0x243185beU, 0x550c7dc3U, 0x72be5d74U, 0x80deb1feU, 0x9bdc06a7U,
 632       0xc19bf174U, 0xe49b69c1U, 0xefbe4786U, 0x0fc19dc6U, 0x240ca1ccU,
 633       0x2de92c6fU, 0x4a7484aaU, 0x5cb0a9dcU, 0x76f988daU, 0x983e5152U,
 634       0xa831c66dU, 0xb00327c8U, 0xbf597fc7U, 0xc6e00bf3U, 0xd5a79147U,
 635       0x06ca6351U, 0x14292967U, 0x27b70a85U, 0x2e1b2138U, 0x4d2c6dfcU,
 636       0x53380d13U, 0x650a7354U, 0x766a0abbU, 0x81c2c92eU, 0x92722c85U,
 637       0xa2bfe8a1U, 0xa81a664bU, 0xc24b8b70U, 0xc76c51a3U, 0xd192e819U,
 638       0xd6990624U, 0xf40e3585U, 0x106aa070U, 0x19a4c116U, 0x1e376c08U,
 639       0x2748774cU, 0x34b0bcb5U, 0x391c0cb3U, 0x4ed8aa4aU, 0x5b9cca4fU,
 640       0x682e6ff3U, 0x748f82eeU, 0x78a5636fU, 0x84c87814U, 0x8cc70208U,
 641       0x90befffaU, 0xa4506cebU, 0xbef9a3f7U, 0xc67178f2U
 642     };  /* 32-bit fractional part of the cube root of the first 64 primes */
 643
 644   unsigned int
 645     A,
 646     B,
 647     C,
 648     D,
 649     E,
 650     F,
 651     G,
 652     H,
 653     shift,
 654     T,
 655     T1,
 656     T2,
 657     W[64];
 658
 659   shift=32;
 660   p=GetStringInfoDatum(signature_info->message);
 661   if (signature_info->lsb_first == MagickFalse)
 662     {
 663       if (sizeof(unsigned int) <= 4)
 664         for (i=0; i < 16; i++)
 665         {
 666           T=(*((unsigned int *) p));
 667           p+=4;
 668           W[i]=Trunc32(T);
 669         }
 670       else
 671         for (i=0; i < 16; i+=2)
 672         {
 673           T=(*((unsigned int *) p));
 674           p+=8;
 675           W[i]=Trunc32(T >> shift);
 676           W[i+1]=Trunc32(T);
 677         }
 678     }
 679   else
 680     if (sizeof(unsigned int) <= 4)
 681       for (i=0; i < 16; i++)
 682       {
 683         T=(*((unsigned int *) p));
 684         p+=4;
 685         W[i]=((T << 24) & 0xff000000) | ((T << 8) & 0x00ff0000) |
 686           ((T >> 8) & 0x0000ff00) | ((T >> 24) & 0x000000ff);
 687       }
 688     else
 689       for (i=0; i < 16; i+=2)
 690       {
 691         T=(*((unsigned int *) p));
 692         p+=8;
 693         W[i]=((T << 24) & 0xff000000) | ((T << 8) & 0x00ff0000) |
 694           ((T >> 8) & 0x0000ff00) | ((T >> 24) & 0x000000ff);
 695         T>>=shift;
 696         W[i+1]=((T << 24) & 0xff000000) | ((T << 8) & 0x00ff0000) |
 697           ((T >> 8) & 0x0000ff00) | ((T >> 24) & 0x000000ff);
 698       }
 699   /*
 700     Copy accumulator to registers.
 701   */
 702   A=signature_info->accumulator[0];
 703   B=signature_info->accumulator[1];
 704   C=signature_info->accumulator[2];
 705   D=signature_info->accumulator[3];
 706   E=signature_info->accumulator[4];
 707   F=signature_info->accumulator[5];
 708   G=signature_info->accumulator[6];
 709   H=signature_info->accumulator[7];
 710   for (i=16; i < 64; i++)
 711     W[i]=Trunc32(Sigma1(W[i-2])+W[i-7]+Sigma0(W[i-15])+W[i-16]);
 712   for (j=0; j < 64; j++)
 713   {
 714     T1=Trunc32(H+Suma1(E)+Ch(E,F,G)+K[j]+W[j]);
 715     T2=Trunc32(Suma0(A)+Maj(A,B,C));
 716     H=G;
 717     G=F;
 718     F=E;
 719     E=Trunc32(D+T1);
 720     D=C;
 721     C=B;
 722     B=A;
 723     A=Trunc32(T1+T2);
 724   }
 725   /*
 726     Add registers back to accumulator.
 727   */
 728   signature_info->accumulator[0]=Trunc32(signature_info->accumulator[0]+A);
 729   signature_info->accumulator[1]=Trunc32(signature_info->accumulator[1]+B);
 730   signature_info->accumulator[2]=Trunc32(signature_info->accumulator[2]+C);
 731   signature_info->accumulator[3]=Trunc32(signature_info->accumulator[3]+D);
 732   signature_info->accumulator[4]=Trunc32(signature_info->accumulator[4]+E);
 733   signature_info->accumulator[5]=Trunc32(signature_info->accumulator[5]+F);
 734   signature_info->accumulator[6]=Trunc32(signature_info->accumulator[6]+G);
 735   signature_info->accumulator[7]=Trunc32(signature_info->accumulator[7]+H);
 736   /*
 737     Reset working registers.
 738   */
 739   A=0;
 740   B=0;
 741   C=0;
 742   D=0;
 743   E=0;
 744   F=0;
 745   G=0;
 746   H=0;
 747   T=0;
 748   T1=0;
 749   T2=0;
 750   (void) ResetMagickMemory(W,0,sizeof(W));
 751 }
 752 \f
 753 /*
 754 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 755 %                                                                             %
 756 %                                                                             %
 757 %                                                                             %
 758 +   U p d a t e S i g n a t u r e                                             %
 759 %                                                                             %
 760 %                                                                             %
 761 %                                                                             %
 762 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 763 %
 764 %  UpdateSignature() updates the Signature message accumulator.
 765 %
 766 %  The format of the UpdateSignature method is:
 767 %
 768 %      UpdateSignature(SignatureInfo *signature_info,const StringInfo *message)
 769 %
 770 %  A description of each parameter follows:
 771 %
 772 %    o signature_info: the address of a structure of type SignatureInfo.
 773 %
 774 %    o message: the message.
 775 %
 776 */
 777 MagickPrivate void UpdateSignature(SignatureInfo *signature_info,
 778   const StringInfo *message)
 779 {
 780   register size_t
 781     i;
 782
 783   register unsigned char
 784     *p;
 785
 786   size_t
 787     n;
 788
 789   unsigned int
 790     length;
 791
 792   /*
 793     Update the Signature accumulator.
 794   */
 795   assert(signature_info != (SignatureInfo *) NULL);
 796   assert(signature_info->signature == MagickSignature);
 797   n=GetStringInfoLength(message);
 798   length=Trunc32((unsigned int) (signature_info->low_order+(n << 3)));
 799   if (length < signature_info->low_order)
 800     signature_info->high_order++;
 801   signature_info->low_order=length;
 802   signature_info->high_order+=(unsigned int) (n >> 29);
 803   p=GetStringInfoDatum(message);
 804   if (signature_info->offset != 0)
 805     {
 806       i=GetStringInfoLength(signature_info->message)-signature_info->offset;
 807       if (i > n)
 808         i=n;
 809       (void) CopyMagickMemory(GetStringInfoDatum(signature_info->message)+
 810         signature_info->offset,p,i);
 811       n-=i;
 812       p+=i;
 813       signature_info->offset+=i;
 814       if (signature_info->offset !=
 815           GetStringInfoLength(signature_info->message))
 816         return;
 817       TransformSignature(signature_info);
 818     }
 819   while (n >= GetStringInfoLength(signature_info->message))
 820   {
 821     SetStringInfoDatum(signature_info->message,p);
 822     p+=GetStringInfoLength(signature_info->message);
 823     n-=GetStringInfoLength(signature_info->message);
 824     TransformSignature(signature_info);
 825   }
 826   (void) CopyMagickMemory(GetStringInfoDatum(signature_info->message),p,n);
 827   signature_info->offset=n;
 828   /*
 829     Reset working registers.
 830   */
 831   i=0;
 832   n=0;
 833   length=0;
 834 }