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         pixel=QuantumScale*p[i];
 543         for (j=0; j < (ssize_t) sizeof(pixel); j++)
 544           *q++=(unsigned char) (&pixel)[j];
 545       }
 546       p+=GetPixelChannels(image);
 547     }
 548     SetStringInfoLength(signature,(size_t) (q-pixels));
 549     UpdateSignature(signature_info,signature);
 550   }
 551   image_view=DestroyCacheView(image_view);
 552   FinalizeSignature(signature_info);
 553   hex_signature=StringInfoToHexString(GetSignatureDigest(signature_info));
 554   (void) DeleteImageProperty(image,"signature");
 555   (void) SetImageProperty(image,"signature",hex_signature,exception);
 556   /*
 557     Free resources.
 558   */
 559   hex_signature=DestroyString(hex_signature);
 560   signature=DestroyStringInfo(signature);
 561   signature_info=DestroySignatureInfo(signature_info);
 562   return(MagickTrue);
 563 }
 564 \f
 565 /*
 566 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 567 %                                                                             %
 568 %                                                                             %
 569 %                                                                             %
 570 +   T r a n s f o r m S i g n a t u r e                                       %
 571 %                                                                             %
 572 %                                                                             %
 573 %                                                                             %
 574 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 575 %
 576 %  TransformSignature() transforms the Signature message accumulator.
 577 %
 578 %  The format of the TransformSignature method is:
 579 %
 580 %      TransformSignature(SignatureInfo *signature_info)
 581 %
 582 %  A description of each parameter follows:
 583 %
 584 %    o signature_info: the address of a structure of type SignatureInfo.
 585 %
 586 */
 587
 588 static inline unsigned int Ch(unsigned int x,unsigned int y,unsigned int z)
 589 {
 590   return((x & y) ^ (~x & z));
 591 }
 592
 593 static inline unsigned int Maj(unsigned int x,unsigned int y,unsigned int z)
 594 {
 595   return((x & y) ^ (x & z) ^ (y & z));
 596 }
 597
 598 static inline unsigned int Trunc32(unsigned int x)
 599 {
 600   return((unsigned int) (x & 0xffffffffU));
 601 }
 602
 603 static unsigned int RotateRight(unsigned int x,unsigned int n)
 604 {
 605   return(Trunc32((x >> n) | (x << (32-n))));
 606 }
 607
 608 static void TransformSignature(SignatureInfo *signature_info)
 609 {
 610 #define Sigma0(x)  (RotateRight(x,7) ^ RotateRight(x,18) ^ Trunc32((x) >> 3))
 611 #define Sigma1(x)  (RotateRight(x,17) ^ RotateRight(x,19) ^ Trunc32((x) >> 10))
 612 #define Suma0(x)  (RotateRight(x,2) ^ RotateRight(x,13) ^ RotateRight(x,22))
 613 #define Suma1(x)  (RotateRight(x,6) ^ RotateRight(x,11) ^ RotateRight(x,25))
 614
 615   register ssize_t
 616     i;
 617
 618   register unsigned char
 619     *p;
 620
 621   ssize_t
 622     j;
 623
 624   static unsigned int
 625     K[64] =
 626     {
 627       0x428a2f98U, 0x71374491U, 0xb5c0fbcfU, 0xe9b5dba5U, 0x3956c25bU,
 628       0x59f111f1U, 0x923f82a4U, 0xab1c5ed5U, 0xd807aa98U, 0x12835b01U,
 629       0x243185beU, 0x550c7dc3U, 0x72be5d74U, 0x80deb1feU, 0x9bdc06a7U,
 630       0xc19bf174U, 0xe49b69c1U, 0xefbe4786U, 0x0fc19dc6U, 0x240ca1ccU,
 631       0x2de92c6fU, 0x4a7484aaU, 0x5cb0a9dcU, 0x76f988daU, 0x983e5152U,
 632       0xa831c66dU, 0xb00327c8U, 0xbf597fc7U, 0xc6e00bf3U, 0xd5a79147U,
 633       0x06ca6351U, 0x14292967U, 0x27b70a85U, 0x2e1b2138U, 0x4d2c6dfcU,
 634       0x53380d13U, 0x650a7354U, 0x766a0abbU, 0x81c2c92eU, 0x92722c85U,
 635       0xa2bfe8a1U, 0xa81a664bU, 0xc24b8b70U, 0xc76c51a3U, 0xd192e819U,
 636       0xd6990624U, 0xf40e3585U, 0x106aa070U, 0x19a4c116U, 0x1e376c08U,
 637       0x2748774cU, 0x34b0bcb5U, 0x391c0cb3U, 0x4ed8aa4aU, 0x5b9cca4fU,
 638       0x682e6ff3U, 0x748f82eeU, 0x78a5636fU, 0x84c87814U, 0x8cc70208U,
 639       0x90befffaU, 0xa4506cebU, 0xbef9a3f7U, 0xc67178f2U
 640     };  /* 32-bit fractional part of the cube root of the first 64 primes */
 641
 642   unsigned int
 643     A,
 644     B,
 645     C,
 646     D,
 647     E,
 648     F,
 649     G,
 650     H,
 651     shift,
 652     T,
 653     T1,
 654     T2,
 655     W[64];
 656
 657   shift=32;
 658   p=GetStringInfoDatum(signature_info->message);
 659   if (signature_info->lsb_first == MagickFalse)
 660     {
 661       if (sizeof(unsigned int) <= 4)
 662         for (i=0; i < 16; i++)
 663         {
 664           T=(*((unsigned int *) p));
 665           p+=4;
 666           W[i]=Trunc32(T);
 667         }
 668       else
 669         for (i=0; i < 16; i+=2)
 670         {
 671           T=(*((unsigned int *) p));
 672           p+=8;
 673           W[i]=Trunc32(T >> shift);
 674           W[i+1]=Trunc32(T);
 675         }
 676     }
 677   else
 678     if (sizeof(unsigned int) <= 4)
 679       for (i=0; i < 16; i++)
 680       {
 681         T=(*((unsigned int *) p));
 682         p+=4;
 683         W[i]=((T << 24) & 0xff000000) | ((T << 8) & 0x00ff0000) |
 684           ((T >> 8) & 0x0000ff00) | ((T >> 24) & 0x000000ff);
 685       }
 686     else
 687       for (i=0; i < 16; i+=2)
 688       {
 689         T=(*((unsigned int *) p));
 690         p+=8;
 691         W[i]=((T << 24) & 0xff000000) | ((T << 8) & 0x00ff0000) |
 692           ((T >> 8) & 0x0000ff00) | ((T >> 24) & 0x000000ff);
 693         T>>=shift;
 694         W[i+1]=((T << 24) & 0xff000000) | ((T << 8) & 0x00ff0000) |
 695           ((T >> 8) & 0x0000ff00) | ((T >> 24) & 0x000000ff);
 696       }
 697   /*
 698     Copy accumulator to registers.
 699   */
 700   A=signature_info->accumulator[0];
 701   B=signature_info->accumulator[1];
 702   C=signature_info->accumulator[2];
 703   D=signature_info->accumulator[3];
 704   E=signature_info->accumulator[4];
 705   F=signature_info->accumulator[5];
 706   G=signature_info->accumulator[6];
 707   H=signature_info->accumulator[7];
 708   for (i=16; i < 64; i++)
 709     W[i]=Trunc32(Sigma1(W[i-2])+W[i-7]+Sigma0(W[i-15])+W[i-16]);
 710   for (j=0; j < 64; j++)
 711   {
 712     T1=Trunc32(H+Suma1(E)+Ch(E,F,G)+K[j]+W[j]);
 713     T2=Trunc32(Suma0(A)+Maj(A,B,C));
 714     H=G;
 715     G=F;
 716     F=E;
 717     E=Trunc32(D+T1);
 718     D=C;
 719     C=B;
 720     B=A;
 721     A=Trunc32(T1+T2);
 722   }
 723   /*
 724     Add registers back to accumulator.
 725   */
 726   signature_info->accumulator[0]=Trunc32(signature_info->accumulator[0]+A);
 727   signature_info->accumulator[1]=Trunc32(signature_info->accumulator[1]+B);
 728   signature_info->accumulator[2]=Trunc32(signature_info->accumulator[2]+C);
 729   signature_info->accumulator[3]=Trunc32(signature_info->accumulator[3]+D);
 730   signature_info->accumulator[4]=Trunc32(signature_info->accumulator[4]+E);
 731   signature_info->accumulator[5]=Trunc32(signature_info->accumulator[5]+F);
 732   signature_info->accumulator[6]=Trunc32(signature_info->accumulator[6]+G);
 733   signature_info->accumulator[7]=Trunc32(signature_info->accumulator[7]+H);
 734   /*
 735     Reset working registers.
 736   */
 737   A=0;
 738   B=0;
 739   C=0;
 740   D=0;
 741   E=0;
 742   F=0;
 743   G=0;
 744   H=0;
 745   T=0;
 746   T1=0;
 747   T2=0;
 748   (void) ResetMagickMemory(W,0,sizeof(W));
 749 }
 750 \f
 751 /*
 752 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 753 %                                                                             %
 754 %                                                                             %
 755 %                                                                             %
 756 +   U p d a t e S i g n a t u r e                                             %
 757 %                                                                             %
 758 %                                                                             %
 759 %                                                                             %
 760 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 761 %
 762 %  UpdateSignature() updates the Signature message accumulator.
 763 %
 764 %  The format of the UpdateSignature method is:
 765 %
 766 %      UpdateSignature(SignatureInfo *signature_info,const StringInfo *message)
 767 %
 768 %  A description of each parameter follows:
 769 %
 770 %    o signature_info: the address of a structure of type SignatureInfo.
 771 %
 772 %    o message: the message.
 773 %
 774 */
 775 MagickPrivate void UpdateSignature(SignatureInfo *signature_info,
 776   const StringInfo *message)
 777 {
 778   register size_t
 779     i;
 780
 781   register unsigned char
 782     *p;
 783
 784   size_t
 785     n;
 786
 787   unsigned int
 788     length;
 789
 790   /*
 791     Update the Signature accumulator.
 792   */
 793   assert(signature_info != (SignatureInfo *) NULL);
 794   assert(signature_info->signature == MagickSignature);
 795   n=GetStringInfoLength(message);
 796   length=Trunc32((unsigned int) (signature_info->low_order+(n << 3)));
 797   if (length < signature_info->low_order)
 798     signature_info->high_order++;
 799   signature_info->low_order=length;
 800   signature_info->high_order+=(unsigned int) (n >> 29);
 801   p=GetStringInfoDatum(message);
 802   if (signature_info->offset != 0)
 803     {
 804       i=GetStringInfoLength(signature_info->message)-signature_info->offset;
 805       if (i > n)
 806         i=n;
 807       (void) CopyMagickMemory(GetStringInfoDatum(signature_info->message)+
 808         signature_info->offset,p,i);
 809       n-=i;
 810       p+=i;
 811       signature_info->offset+=i;
 812       if (signature_info->offset !=
 813           GetStringInfoLength(signature_info->message))
 814         return;
 815       TransformSignature(signature_info);
 816     }
 817   while (n >= GetStringInfoLength(signature_info->message))
 818   {
 819     SetStringInfoDatum(signature_info->message,p);
 820     p+=GetStringInfoLength(signature_info->message);
 821     n-=GetStringInfoLength(signature_info->message);
 822     TransformSignature(signature_info);
 823   }
 824   (void) CopyMagickMemory(GetStringInfoDatum(signature_info->message),p,n);
 825   signature_info->offset=n;
 826   /*
 827     Reset working registers.
 828   */
 829   i=0;
 830   n=0;
 831   length=0;
 832 }