2 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
5 % RRRR AAA N N DDDD OOO M M %
6 % R R A A NN N D D O O MM MM %
7 % RRRR AAAAA N N N D D O O M M M %
8 % R R A A N NN D D O O M M %
9 % R R A A N N DDDD OOO M M %
12 % MagickCore Methods to Generate Random Numbers %
19 % Copyright 1999-2014 ImageMagick Studio LLC, a non-profit organization %
20 % dedicated to making software imaging solutions freely available. %
22 % You may not use this file except in compliance with the License. You may %
23 % obtain a copy of the License at %
25 % http://www.imagemagick.org/script/license.php %
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. %
33 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
35 % The generation of random numbers is too important to be left to chance.
36 % -- Tom Christiansen <tchrist@mox.perl.com>
47 #if defined(__MINGW32__) || defined(__MINGW64__)
50 #include "MagickCore/studio.h"
51 #include "MagickCore/exception.h"
52 #include "MagickCore/exception-private.h"
53 #include "MagickCore/memory_.h"
54 #include "MagickCore/semaphore.h"
55 #include "MagickCore/random_.h"
56 #include "MagickCore/random-private.h"
57 #include "MagickCore/resource_.h"
58 #include "MagickCore/signature-private.h"
59 #include "MagickCore/string_.h"
60 #include "MagickCore/thread_.h"
61 #include "MagickCore/thread-private.h"
62 #include "MagickCore/utility.h"
63 #include "MagickCore/utility-private.h"
67 #define PseudoRandomHash SHA256Hash
68 #define RandomEntropyLevel 9
69 #define RandomFilename "reservoir.xdm"
70 #define RandomFiletype "random"
71 #define RandomProtocolMajorVersion 1
72 #define RandomProtocolMinorVersion 0
113 External declarations.
115 #if defined(__APPLE__) && !defined(TARGET_OS_IPHONE)
116 #include <crt_externs.h>
117 #define environ (*_NSGetEnviron())
120 #if !defined(MAGICKCORE_WINDOWS_SUPPORT)
129 *random_semaphore = (SemaphoreInfo *) NULL;
134 static MagickBooleanType
135 gather_true_random = MagickFalse;
138 Forward declarations.
141 *GenerateEntropicChaos(RandomInfo *);
144 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
148 % A c q u i r e R a n d o m I n f o %
152 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
154 % AcquireRandomInfo() allocates the RandomInfo structure.
156 % The format of the AcquireRandomInfo method is:
158 % RandomInfo *AcquireRandomInfo(void)
162 static inline size_t MagickMin(const size_t x,const size_t y)
169 MagickExport RandomInfo *AcquireRandomInfo(void)
182 random_info=(RandomInfo *) AcquireMagickMemory(sizeof(*random_info));
183 if (random_info == (RandomInfo *) NULL)
184 ThrowFatalException(ResourceLimitFatalError,"MemoryAllocationFailed");
185 (void) ResetMagickMemory(random_info,0,sizeof(*random_info));
186 random_info->signature_info=AcquireSignatureInfo();
187 random_info->nonce=AcquireStringInfo(2*GetSignatureDigestsize(
188 random_info->signature_info));
189 ResetStringInfo(random_info->nonce);
190 random_info->reservoir=AcquireStringInfo(GetSignatureDigestsize(
191 random_info->signature_info));
192 ResetStringInfo(random_info->reservoir);
193 random_info->normalize=1.0/(~0UL);
194 random_info->secret_key=secret_key;
195 random_info->protocol_major=RandomProtocolMajorVersion;
196 random_info->protocol_minor=RandomProtocolMinorVersion;
197 random_info->semaphore=AcquireSemaphoreInfo();
198 random_info->timestamp=(ssize_t) time(0);
199 random_info->signature=MagickSignature;
203 nonce=GenerateEntropicChaos(random_info);
204 if (nonce == (StringInfo *) NULL)
205 ThrowFatalException(ResourceLimitFatalError,"MemoryAllocationFailed");
206 InitializeSignature(random_info->signature_info);
207 UpdateSignature(random_info->signature_info,nonce);
208 FinalizeSignature(random_info->signature_info);
209 SetStringInfoLength(nonce,(GetSignatureDigestsize(
210 random_info->signature_info)+1)/2);
211 SetStringInfo(nonce,GetSignatureDigest(random_info->signature_info));
212 SetStringInfo(random_info->nonce,nonce);
213 nonce=DestroyStringInfo(nonce);
215 Seed random reservoir with entropic data.
217 entropy=GenerateEntropicChaos(random_info);
218 if (entropy == (StringInfo *) NULL)
219 ThrowFatalException(ResourceLimitFatalError,"MemoryAllocationFailed");
220 UpdateSignature(random_info->signature_info,entropy);
221 FinalizeSignature(random_info->signature_info);
222 SetStringInfo(random_info->reservoir,GetSignatureDigest(
223 random_info->signature_info));
224 entropy=DestroyStringInfo(entropy);
226 Seed pseudo random number generator.
228 if (random_info->secret_key == ~0UL)
230 key=GetRandomKey(random_info,sizeof(random_info->secret_key));
231 (void) CopyMagickMemory(random_info->seed,GetStringInfoDatum(key),
232 GetStringInfoLength(key));
233 key=DestroyStringInfo(key);
240 signature_info=AcquireSignatureInfo();
241 key=AcquireStringInfo(sizeof(random_info->secret_key));
242 SetStringInfoDatum(key,(unsigned char *) &random_info->secret_key);
243 UpdateSignature(signature_info,key);
244 key=DestroyStringInfo(key);
245 FinalizeSignature(signature_info);
246 digest=GetSignatureDigest(signature_info);
247 (void) CopyMagickMemory(random_info->seed,GetStringInfoDatum(digest),
248 MagickMin(GetSignatureDigestsize(signature_info),
249 sizeof(*random_info->seed)));
250 signature_info=DestroySignatureInfo(signature_info);
252 random_info->seed[1]=0x50a7f451UL;
253 random_info->seed[2]=0x5365417eUL;
254 random_info->seed[3]=0xc3a4171aUL;
259 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
263 + D e s t r o y R a n d o m I n f o %
267 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
269 % DestroyRandomInfo() deallocates memory associated with the random
272 % The format of the DestroyRandomInfo method is:
274 % RandomInfo *DestroyRandomInfo(RandomInfo *random_info)
276 % A description of each parameter follows:
278 % o random_info: the random info.
281 MagickExport RandomInfo *DestroyRandomInfo(RandomInfo *random_info)
283 (void) LogMagickEvent(TraceEvent,GetMagickModule(),"...");
284 assert(random_info != (RandomInfo *) NULL);
285 assert(random_info->signature == MagickSignature);
286 LockSemaphoreInfo(random_info->semaphore);
287 if (random_info->reservoir != (StringInfo *) NULL)
288 random_info->reservoir=DestroyStringInfo(random_info->reservoir);
289 if (random_info->nonce != (StringInfo *) NULL)
290 random_info->nonce=DestroyStringInfo(random_info->nonce);
291 if (random_info->signature_info != (SignatureInfo *) NULL)
292 random_info->signature_info=DestroySignatureInfo(
293 random_info->signature_info);
294 (void) ResetMagickMemory(random_info->seed,0,sizeof(*random_info->seed));
295 random_info->signature=(~MagickSignature);
296 UnlockSemaphoreInfo(random_info->semaphore);
297 RelinquishSemaphoreInfo(&random_info->semaphore);
298 random_info=(RandomInfo *) RelinquishMagickMemory(random_info);
303 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
307 + G e n e r a t e E n t r o p i c C h a o s %
311 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
313 % GenerateEntropicChaos() generate entropic chaos used to initialize the
316 % The format of the GenerateEntropicChaos method is:
318 % StringInfo *GenerateEntropicChaos(RandomInfo *random_info)
320 % A description of each parameter follows:
322 % o random_info: the random info.
326 #if !defined(MAGICKCORE_WINDOWS_SUPPORT)
327 static ssize_t ReadRandom(int file,unsigned char *source,size_t length)
329 register unsigned char
337 for (q=source; length != 0; length-=count)
339 count=(ssize_t) read(file,q,length);
354 static StringInfo *GenerateEntropicChaos(RandomInfo *random_info)
356 #define MaxEntropyExtent 64
373 Initialize random reservoir.
375 entropy=AcquireStringInfo(0);
376 LockSemaphoreInfo(random_info->semaphore);
377 chaos=AcquireStringInfo(sizeof(unsigned char *));
378 SetStringInfoDatum(chaos,(unsigned char *) &entropy);
379 ConcatenateStringInfo(entropy,chaos);
380 SetStringInfoDatum(chaos,(unsigned char *) entropy);
381 ConcatenateStringInfo(entropy,chaos);
382 pid=(ssize_t) getpid();
383 SetStringInfoLength(chaos,sizeof(pid));
384 SetStringInfoDatum(chaos,(unsigned char *) &pid);
385 ConcatenateStringInfo(entropy,chaos);
386 tid=GetMagickThreadId();
387 SetStringInfoLength(chaos,sizeof(tid));
388 SetStringInfoDatum(chaos,(unsigned char *) &tid);
389 ConcatenateStringInfo(entropy,chaos);
390 #if defined(MAGICKCORE_HAVE_GETRUSAGE) && defined(RUSAGE_SELF)
395 if (getrusage(RUSAGE_SELF,&usage) == 0)
397 SetStringInfoLength(chaos,sizeof(usage));
398 SetStringInfoDatum(chaos,(unsigned char *) &usage);
402 seconds=time((time_t *) 0);
404 #if defined(MAGICKCORE_HAVE_GETTIMEOFDAY)
409 if (gettimeofday(&timer,(struct timezone *) NULL) == 0)
411 seconds=timer.tv_sec;
412 nanoseconds=1000UL*timer.tv_usec;
416 #if defined(MAGICKCORE_HAVE_CLOCK_GETTIME) && defined(CLOCK_REALTIME_HR)
421 if (clock_gettime(CLOCK_REALTIME_HR,&timer) == 0)
423 seconds=timer.tv_sec;
424 nanoseconds=timer.tv_nsec;
428 SetStringInfoLength(chaos,sizeof(seconds));
429 SetStringInfoDatum(chaos,(unsigned char *) &seconds);
430 ConcatenateStringInfo(entropy,chaos);
431 SetStringInfoLength(chaos,sizeof(nanoseconds));
432 SetStringInfoDatum(chaos,(unsigned char *) &nanoseconds);
433 ConcatenateStringInfo(entropy,chaos);
435 #if defined(MAGICKCORE_HAVE_CLOCK)
438 #if defined(MAGICKCORE_HAVE_TIMES)
443 (void) times(&timer);
444 nanoseconds=timer.tms_utime+timer.tms_stime;
447 SetStringInfoLength(chaos,sizeof(nanoseconds));
448 SetStringInfoDatum(chaos,(unsigned char *) &nanoseconds);
449 ConcatenateStringInfo(entropy,chaos);
450 #if defined(MAGICKCORE_HAVE_MKSTEMP)
458 (void) GetPathTemplate(path);
461 setmode(file,O_BINARY);
465 (void) remove_utf8(path);
466 SetStringInfoLength(chaos,strlen(path));
467 SetStringInfoDatum(chaos,(unsigned char *) path);
468 ConcatenateStringInfo(entropy,chaos);
471 #if defined(MAGICKCORE_WINDOWS_SUPPORT)
483 Not crytographically strong but better than nothing.
485 seconds=NTElapsedTime()+NTUserTime();
486 SetStringInfoLength(chaos,sizeof(seconds));
487 SetStringInfoDatum(chaos,(unsigned char *) &seconds);
488 ConcatenateStringInfo(entropy,chaos);
489 if (QueryPerformanceCounter(&nanoseconds) != 0)
491 SetStringInfoLength(chaos,sizeof(nanoseconds));
492 SetStringInfoDatum(chaos,(unsigned char *) &nanoseconds);
493 ConcatenateStringInfo(entropy,chaos);
496 Our best hope for true entropy.
498 SetStringInfoLength(chaos,MaxEntropyExtent);
499 status=NTGatherRandomData(MaxEntropyExtent,GetStringInfoDatum(chaos));
501 ConcatenateStringInfo(entropy,chaos);
518 Not crytographically strong but better than nothing.
520 if (environ != (char **) NULL)
526 Squeeze some entropy from the sometimes unpredicatble environment.
528 for (i=0; environ[i] != (char *) NULL; i++)
530 SetStringInfoLength(chaos,strlen(environ[i]));
531 SetStringInfoDatum(chaos,(unsigned char *) environ[i]);
532 ConcatenateStringInfo(entropy,chaos);
535 filename=AcquireString("/dev/urandom");
536 device=StringToStringInfo(filename);
537 device=DestroyStringInfo(device);
538 file=open_utf8(filename,O_RDONLY | O_BINARY,0);
539 filename=DestroyString(filename);
542 SetStringInfoLength(chaos,MaxEntropyExtent);
543 count=ReadRandom(file,GetStringInfoDatum(chaos),MaxEntropyExtent);
545 SetStringInfoLength(chaos,(size_t) count);
546 ConcatenateStringInfo(entropy,chaos);
548 if (gather_true_random != MagickFalse)
551 Our best hope for true entropy.
553 filename=AcquireString("/dev/random");
554 device=StringToStringInfo(filename);
555 device=DestroyStringInfo(device);
556 file=open_utf8(filename,O_RDONLY | O_BINARY,0);
557 filename=DestroyString(filename);
560 filename=AcquireString("/dev/srandom");
561 device=StringToStringInfo(filename);
562 device=DestroyStringInfo(device);
563 file=open_utf8(filename,O_RDONLY | O_BINARY,0);
567 SetStringInfoLength(chaos,MaxEntropyExtent);
568 count=ReadRandom(file,GetStringInfoDatum(chaos),MaxEntropyExtent);
570 SetStringInfoLength(chaos,(size_t) count);
571 ConcatenateStringInfo(entropy,chaos);
576 chaos=DestroyStringInfo(chaos);
577 UnlockSemaphoreInfo(random_info->semaphore);
582 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
586 % G e t P s e u d o R a n d o m V a l u e %
590 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
592 % GetPseudoRandomValue() return a non-negative double-precision floating-point
593 % value uniformly distributed over the interval [0.0, 1.0) with a 2 to the
596 % The format of the GetPseudoRandomValue method is:
598 % double GetPseudoRandomValue(RandomInfo *randon_info)
600 % A description of each parameter follows:
602 % o random_info: the random info.
605 MagickExport double GetPseudoRandomValue(RandomInfo *random_info)
607 register unsigned long
613 seed=random_info->seed;
616 alpha=(unsigned long) (seed[1] ^ (seed[1] << 11));
620 seed[0]=(seed[0] ^ (seed[0] >> 19)) ^ (alpha ^ (alpha >> 8));
621 } while (seed[0] == ~0UL);
622 return(random_info->normalize*seed[0]);
626 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
630 % G e t R a n d o m K e y %
634 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
636 % GetRandomKey() gets a random key from the reservoir.
638 % The format of the GetRandomKey method is:
640 % StringInfo *GetRandomKey(RandomInfo *random_info,const size_t length)
642 % A description of each parameter follows:
644 % o random_info: the random info.
646 % o length: the key length.
649 MagickExport StringInfo *GetRandomKey(RandomInfo *random_info,
655 assert(random_info != (RandomInfo *) NULL);
656 key=AcquireStringInfo(length);
657 SetRandomKey(random_info,length,GetStringInfoDatum(key));
662 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
666 % G e t R a n d o m S e c r e t K e y %
670 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
672 % GetRandomSecretKey() returns the random secet key.
674 % The format of the GetRandomSecretKey method is:
676 % unsigned long GetRandomSecretKey(const RandomInfo *random_info)
678 % A description of each parameter follows:
680 % o random_info: the random info.
682 MagickExport unsigned long GetRandomSecretKey(const RandomInfo *random_info)
684 return(random_info->secret_key);
688 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
692 % G e t R a n d o m V a l u e %
696 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
698 % GetRandomValue() return a non-negative double-precision floating-point
699 % value uniformly distributed over the interval [0.0, 1.0) with a 2 to the
700 % 128th-1 period (not cryptographically strong).
702 % The format of the GetRandomValue method is:
704 % double GetRandomValue(void)
707 MagickExport double GetRandomValue(RandomInfo *random_info)
716 SetRandomKey(random_info,sizeof(key),(unsigned char *) &key);
717 } while (key == range);
718 return((double) key/range);
722 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
726 + R a n d o m C o m p o n e n t G e n e s i s %
730 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
732 % RandomComponentGenesis() instantiates the random component.
734 % The format of the RandomComponentGenesis method is:
736 % MagickBooleanType RandomComponentGenesis(void)
739 MagickPrivate MagickBooleanType RandomComponentGenesis(void)
741 if (random_semaphore == (SemaphoreInfo *) NULL)
742 random_semaphore=AcquireSemaphoreInfo();
747 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
751 + R a n d o m C o m p o n e n t T e r m i n u s %
755 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
757 % RandomComponentTerminus() destroys the random component.
759 % The format of the RandomComponentTerminus method is:
761 % RandomComponentTerminus(void)
764 MagickPrivate void RandomComponentTerminus(void)
766 if (random_semaphore == (SemaphoreInfo *) NULL)
767 ActivateSemaphoreInfo(&random_semaphore);
768 RelinquishSemaphoreInfo(&random_semaphore);
772 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
776 % S e t R a n d o m K e y %
780 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
782 % SetRandomKey() sets a random key from the reservoir.
784 % The format of the SetRandomKey method is:
786 % void SetRandomKey(RandomInfo *random_info,const size_t length,
787 % unsigned char *key)
789 % A description of each parameter follows:
791 % o random_info: the random info.
793 % o length: the key length.
799 static inline void IncrementRandomNonce(StringInfo *nonce)
807 datum=GetStringInfoDatum(nonce);
808 for (i=(ssize_t) (GetStringInfoLength(nonce)-1); i != 0; i--)
814 ThrowFatalException(RandomFatalError,"SequenceWrapError");
817 MagickExport void SetRandomKey(RandomInfo *random_info,const size_t length,
823 register unsigned char
832 assert(random_info != (RandomInfo *) NULL);
835 LockSemaphoreInfo(random_info->semaphore);
836 signature_info=random_info->signature_info;
837 datum=GetStringInfoDatum(random_info->reservoir);
839 for (p=key; (i != 0) && (random_info->i != 0); i--)
841 *p++=datum[random_info->i];
843 if (random_info->i == GetSignatureDigestsize(signature_info))
846 while (i >= GetSignatureDigestsize(signature_info))
848 InitializeSignature(signature_info);
849 UpdateSignature(signature_info,random_info->nonce);
850 FinalizeSignature(signature_info);
851 IncrementRandomNonce(random_info->nonce);
852 (void) CopyMagickMemory(p,GetStringInfoDatum(GetSignatureDigest(
853 signature_info)),GetSignatureDigestsize(signature_info));
854 p+=GetSignatureDigestsize(signature_info);
855 i-=GetSignatureDigestsize(signature_info);
859 InitializeSignature(signature_info);
860 UpdateSignature(signature_info,random_info->nonce);
861 FinalizeSignature(signature_info);
862 IncrementRandomNonce(random_info->nonce);
863 SetStringInfo(random_info->reservoir,GetSignatureDigest(signature_info));
865 datum=GetStringInfoDatum(random_info->reservoir);
869 UnlockSemaphoreInfo(random_info->semaphore);
873 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
877 % S e t R a n d o m S e c r e t K e y %
881 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
883 % SetRandomSecretKey() sets the pseudo-random number generator secret key.
885 % The format of the SetRandomSecretKey method is:
887 % void SetRandomSecretKey(const unsigned long key)
889 % A description of each parameter follows:
891 % o key: the secret seed.
894 MagickExport void SetRandomSecretKey(const unsigned long key)
900 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
904 % S e t R a n d o m T r u e R a n d o m %
908 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
910 % SetRandomTrueRandom() declares your intentions to use true random numbers.
911 % True random numbers are encouraged but may not always be practical because
912 % your application may block while entropy is gathered from your environment.
914 % The format of the SetRandomTrueRandom method is:
916 % void SetRandomTrueRandom(const MagickBooleanType true_random)
918 % A description of each parameter follows:
920 % o true_random: declare your intentions to use true-random number.
923 MagickExport void SetRandomTrueRandom(const MagickBooleanType true_random)
925 gather_true_random=true_random;
928 MagickPrivate unsigned long *GetRandomInfoSeed(RandomInfo *random_info)
930 assert(random_info != (RandomInfo *) NULL);
931 return random_info->seed;
934 MagickPrivate double GetRandomInfoNormalize(RandomInfo *random_info)
936 assert(random_info != (RandomInfo *) NULL);
937 return random_info->normalize;