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 1999-2011 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         PixelTrait
 530           traits;
 531
 532         register ssize_t
 533           j;
 534
 535         traits=GetPixelChannelMapTraits(image,(PixelChannel) i);
 536         if (traits == UndefinedPixelTrait)
 537           continue;
 538         if ((traits & UpdatePixelTrait) == 0)
 539           continue;
 540         pixel=QuantumScale*p[i];
 541         for (j=0; j < (ssize_t) sizeof(pixel); j++)
 542           *q++=(unsigned char) (&pixel)[j];
 543       }
 544       p+=GetPixelChannels(image);
 545     }
 546     SetStringInfoLength(signature,(size_t) (q-pixels));
 547     UpdateSignature(signature_info,signature);
 548   }
 549   image_view=DestroyCacheView(image_view);
 550   FinalizeSignature(signature_info);
 551   hex_signature=StringInfoToHexString(GetSignatureDigest(signature_info));
 552   (void) DeleteImageProperty(image,"signature");
 553   (void) SetImageProperty(image,"signature",hex_signature,exception);
 554   /*
 555     Free resources.
 556   */
 557   hex_signature=DestroyString(hex_signature);
 558   signature=DestroyStringInfo(signature);
 559   signature_info=DestroySignatureInfo(signature_info);
 560   return(MagickTrue);
 561 }
 562 \f
 563 /*
 564 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 565 %                                                                             %
 566 %                                                                             %
 567 %                                                                             %
 568 +   T r a n s f o r m S i g n a t u r e                                       %
 569 %                                                                             %
 570 %                                                                             %
 571 %                                                                             %
 572 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 573 %
 574 %  TransformSignature() transforms the Signature message accumulator.
 575 %
 576 %  The format of the TransformSignature method is:
 577 %
 578 %      TransformSignature(SignatureInfo *signature_info)
 579 %
 580 %  A description of each parameter follows:
 581 %
 582 %    o signature_info: the address of a structure of type SignatureInfo.
 583 %
 584 */
 585
 586 static inline unsigned int Ch(unsigned int x,unsigned int y,unsigned int z)
 587 {
 588   return((x & y) ^ (~x & z));
 589 }
 590
 591 static inline unsigned int Maj(unsigned int x,unsigned int y,unsigned int z)
 592 {
 593   return((x & y) ^ (x & z) ^ (y & z));
 594 }
 595
 596 static inline unsigned int Trunc32(unsigned int x)
 597 {
 598   return((unsigned int) (x & 0xffffffffU));
 599 }
 600
 601 static unsigned int RotateRight(unsigned int x,unsigned int n)
 602 {
 603   return(Trunc32((x >> n) | (x << (32-n))));
 604 }
 605
 606 static void TransformSignature(SignatureInfo *signature_info)
 607 {
 608 #define Sigma0(x)  (RotateRight(x,7) ^ RotateRight(x,18) ^ Trunc32((x) >> 3))
 609 #define Sigma1(x)  (RotateRight(x,17) ^ RotateRight(x,19) ^ Trunc32((x) >> 10))
 610 #define Suma0(x)  (RotateRight(x,2) ^ RotateRight(x,13) ^ RotateRight(x,22))
 611 #define Suma1(x)  (RotateRight(x,6) ^ RotateRight(x,11) ^ RotateRight(x,25))
 612
 613   register ssize_t
 614     i;
 615
 616   register unsigned char
 617     *p;
 618
 619   ssize_t
 620     j;
 621
 622   static unsigned int
 623     K[64] =
 624     {
 625       0x428a2f98U, 0x71374491U, 0xb5c0fbcfU, 0xe9b5dba5U, 0x3956c25bU,
 626       0x59f111f1U, 0x923f82a4U, 0xab1c5ed5U, 0xd807aa98U, 0x12835b01U,
 627       0x243185beU, 0x550c7dc3U, 0x72be5d74U, 0x80deb1feU, 0x9bdc06a7U,
 628       0xc19bf174U, 0xe49b69c1U, 0xefbe4786U, 0x0fc19dc6U, 0x240ca1ccU,
 629       0x2de92c6fU, 0x4a7484aaU, 0x5cb0a9dcU, 0x76f988daU, 0x983e5152U,
 630       0xa831c66dU, 0xb00327c8U, 0xbf597fc7U, 0xc6e00bf3U, 0xd5a79147U,
 631       0x06ca6351U, 0x14292967U, 0x27b70a85U, 0x2e1b2138U, 0x4d2c6dfcU,
 632       0x53380d13U, 0x650a7354U, 0x766a0abbU, 0x81c2c92eU, 0x92722c85U,
 633       0xa2bfe8a1U, 0xa81a664bU, 0xc24b8b70U, 0xc76c51a3U, 0xd192e819U,
 634       0xd6990624U, 0xf40e3585U, 0x106aa070U, 0x19a4c116U, 0x1e376c08U,
 635       0x2748774cU, 0x34b0bcb5U, 0x391c0cb3U, 0x4ed8aa4aU, 0x5b9cca4fU,
 636       0x682e6ff3U, 0x748f82eeU, 0x78a5636fU, 0x84c87814U, 0x8cc70208U,
 637       0x90befffaU, 0xa4506cebU, 0xbef9a3f7U, 0xc67178f2U
 638     };  /* 32-bit fractional part of the cube root of the first 64 primes */
 639
 640   unsigned int
 641     A,
 642     B,
 643     C,
 644     D,
 645     E,
 646     F,
 647     G,
 648     H,
 649     shift,
 650     T,
 651     T1,
 652     T2,
 653     W[64];
 654
 655   shift=32;
 656   p=GetStringInfoDatum(signature_info->message);
 657   if (signature_info->lsb_first == MagickFalse)
 658     {
 659       if (sizeof(unsigned int) <= 4)
 660         for (i=0; i < 16; i++)
 661         {
 662           T=(*((unsigned int *) p));
 663           p+=4;
 664           W[i]=Trunc32(T);
 665         }
 666       else
 667         for (i=0; i < 16; i+=2)
 668         {
 669           T=(*((unsigned int *) p));
 670           p+=8;
 671           W[i]=Trunc32(T >> shift);
 672           W[i+1]=Trunc32(T);
 673         }
 674     }
 675   else
 676     if (sizeof(unsigned int) <= 4)
 677       for (i=0; i < 16; i++)
 678       {
 679         T=(*((unsigned int *) p));
 680         p+=4;
 681         W[i]=((T << 24) & 0xff000000) | ((T << 8) & 0x00ff0000) |
 682           ((T >> 8) & 0x0000ff00) | ((T >> 24) & 0x000000ff);
 683       }
 684     else
 685       for (i=0; i < 16; i+=2)
 686       {
 687         T=(*((unsigned int *) p));
 688         p+=8;
 689         W[i]=((T << 24) & 0xff000000) | ((T << 8) & 0x00ff0000) |
 690           ((T >> 8) & 0x0000ff00) | ((T >> 24) & 0x000000ff);
 691         T>>=shift;
 692         W[i+1]=((T << 24) & 0xff000000) | ((T << 8) & 0x00ff0000) |
 693           ((T >> 8) & 0x0000ff00) | ((T >> 24) & 0x000000ff);
 694       }
 695   /*
 696     Copy accumulator to registers.
 697   */
 698   A=signature_info->accumulator[0];
 699   B=signature_info->accumulator[1];
 700   C=signature_info->accumulator[2];
 701   D=signature_info->accumulator[3];
 702   E=signature_info->accumulator[4];
 703   F=signature_info->accumulator[5];
 704   G=signature_info->accumulator[6];
 705   H=signature_info->accumulator[7];
 706   for (i=16; i < 64; i++)
 707     W[i]=Trunc32(Sigma1(W[i-2])+W[i-7]+Sigma0(W[i-15])+W[i-16]);
 708   for (j=0; j < 64; j++)
 709   {
 710     T1=Trunc32(H+Suma1(E)+Ch(E,F,G)+K[j]+W[j]);
 711     T2=Trunc32(Suma0(A)+Maj(A,B,C));
 712     H=G;
 713     G=F;
 714     F=E;
 715     E=Trunc32(D+T1);
 716     D=C;
 717     C=B;
 718     B=A;
 719     A=Trunc32(T1+T2);
 720   }
 721   /*
 722     Add registers back to accumulator.
 723   */
 724   signature_info->accumulator[0]=Trunc32(signature_info->accumulator[0]+A);
 725   signature_info->accumulator[1]=Trunc32(signature_info->accumulator[1]+B);
 726   signature_info->accumulator[2]=Trunc32(signature_info->accumulator[2]+C);
 727   signature_info->accumulator[3]=Trunc32(signature_info->accumulator[3]+D);
 728   signature_info->accumulator[4]=Trunc32(signature_info->accumulator[4]+E);
 729   signature_info->accumulator[5]=Trunc32(signature_info->accumulator[5]+F);
 730   signature_info->accumulator[6]=Trunc32(signature_info->accumulator[6]+G);
 731   signature_info->accumulator[7]=Trunc32(signature_info->accumulator[7]+H);
 732   /*
 733     Reset working registers.
 734   */
 735   A=0;
 736   B=0;
 737   C=0;
 738   D=0;
 739   E=0;
 740   F=0;
 741   G=0;
 742   H=0;
 743   T=0;
 744   T1=0;
 745   T2=0;
 746   (void) ResetMagickMemory(W,0,sizeof(W));
 747 }
 748 \f
 749 /*
 750 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 751 %                                                                             %
 752 %                                                                             %
 753 %                                                                             %
 754 +   U p d a t e S i g n a t u r e                                             %
 755 %                                                                             %
 756 %                                                                             %
 757 %                                                                             %
 758 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 759 %
 760 %  UpdateSignature() updates the Signature message accumulator.
 761 %
 762 %  The format of the UpdateSignature method is:
 763 %
 764 %      UpdateSignature(SignatureInfo *signature_info,const StringInfo *message)
 765 %
 766 %  A description of each parameter follows:
 767 %
 768 %    o signature_info: the address of a structure of type SignatureInfo.
 769 %
 770 %    o message: the message.
 771 %
 772 */
 773 MagickPrivate void UpdateSignature(SignatureInfo *signature_info,
 774   const StringInfo *message)
 775 {
 776   register size_t
 777     i;
 778
 779   register unsigned char
 780     *p;
 781
 782   size_t
 783     n;
 784
 785   unsigned int
 786     length;
 787
 788   /*
 789     Update the Signature accumulator.
 790   */
 791   assert(signature_info != (SignatureInfo *) NULL);
 792   assert(signature_info->signature == MagickSignature);
 793   n=GetStringInfoLength(message);
 794   length=Trunc32((unsigned int) (signature_info->low_order+(n << 3)));
 795   if (length < signature_info->low_order)
 796     signature_info->high_order++;
 797   signature_info->low_order=length;
 798   signature_info->high_order+=(unsigned int) (n >> 29);
 799   p=GetStringInfoDatum(message);
 800   if (signature_info->offset != 0)
 801     {
 802       i=GetStringInfoLength(signature_info->message)-signature_info->offset;
 803       if (i > n)
 804         i=n;
 805       (void) CopyMagickMemory(GetStringInfoDatum(signature_info->message)+
 806         signature_info->offset,p,i);
 807       n-=i;
 808       p+=i;
 809       signature_info->offset+=i;
 810       if (signature_info->offset !=
 811           GetStringInfoLength(signature_info->message))
 812         return;
 813       TransformSignature(signature_info);
 814     }
 815   while (n >= GetStringInfoLength(signature_info->message))
 816   {
 817     SetStringInfoDatum(signature_info->message,p);
 818     p+=GetStringInfoLength(signature_info->message);
 819     n-=GetStringInfoLength(signature_info->message);
 820     TransformSignature(signature_info);
 821   }
 822   (void) CopyMagickMemory(GetStringInfoDatum(signature_info->message),p,n);
 823   signature_info->offset=n;
 824   /*
 825     Reset working registers.
 826   */
 827   i=0;
 828   n=0;
 829   length=0;
 830 }