MagickCore 7.1.2
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random.c
1/*
2%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
3% %
4% %
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 %
10% %
11% %
12% MagickCore Methods to Generate Random Numbers %
13% %
14% Software Design %
15% Cristy %
16% December 2001 %
17% %
18% %
19% Copyright @ 1999 ImageMagick Studio LLC, a non-profit organization %
20% dedicated to making software imaging solutions freely available. %
21% %
22% You may not use this file except in compliance with the License. You may %
23% obtain a copy of the License at %
24% %
25% https://imagemagick.org/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% The generation of random numbers is too important to be left to chance.
36% -- Tom Christiansen <tchrist@mox.perl.com>
37%
38%
39*/
40␌
41/*
42 Include declarations.
43*/
44#if defined(__VMS)
45#include <time.h>
46#endif
47#if defined(__MINGW32__)
48#include <sys/time.h>
49#endif
50#include "MagickCore/studio.h"
51#include "MagickCore/exception.h"
52#include "MagickCore/exception-private.h"
53#include "MagickCore/image-private.h"
54#include "MagickCore/memory_.h"
55#include "MagickCore/memory-private.h"
56#include "MagickCore/random_.h"
57#include "MagickCore/random-private.h"
58#include "MagickCore/resource_.h"
59#include "MagickCore/semaphore.h"
60#include "MagickCore/signature-private.h"
61#include "MagickCore/string_.h"
62#include "MagickCore/thread_.h"
63#include "MagickCore/thread-private.h"
64#include "MagickCore/timer-private.h"
65#include "MagickCore/utility.h"
66#include "MagickCore/utility-private.h"
67#if defined(MAGICKCORE_HAVE_GETENTROPY)
68#include <sys/random.h>
69#endif
70/*
71 Define declarations.
72*/
73#define PseudoRandomHash SHA256Hash
74#define RandomEntropyLevel 9
75#define RandomFilename "reservoir.xdm"
76#define RandomFiletype "random"
77#define RandomProtocolMajorVersion 1
78#define RandomProtocolMinorVersion 0
79␌
80/*
81 Typedef declarations.
82*/
83struct _RandomInfo
84{
85 SignatureInfo
86 *signature_info;
87
88 StringInfo
89 *nonce,
90 *reservoir;
91
92 size_t
93 i;
94
95 MagickSizeType
96 seed[4];
97
98 double
99 normalize;
100
101 unsigned long
102 secret_key;
103
104 unsigned short
105 protocol_major,
106 protocol_minor;
107
108 SemaphoreInfo
109 *semaphore;
110
111 time_t
112 timestamp;
113
114 size_t
115 signature;
116};
117␌
118/*
119 External declarations.
120*/
121#if defined(__APPLE__) && !defined(TARGET_OS_IPHONE)
122#include <crt_externs.h>
123#define environ (*_NSGetEnviron())
124#endif
125
126#if !defined(MAGICKCORE_WINDOWS_SUPPORT)
127extern char
128 **environ;
129#endif
130␌
131/*
132 Global declarations.
133*/
134static SemaphoreInfo
135 *random_semaphore = (SemaphoreInfo *) NULL;
136
137static unsigned long
138 secret_key = ~0UL;
139
140static MagickBooleanType
141 gather_true_random = MagickFalse;
142␌
143/*
144 Forward declarations.
145*/
146static StringInfo
147 *GenerateEntropicChaos(RandomInfo *);
148␌
149/*
150%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
151% %
152% %
153% %
154% A c q u i r e R a n d o m I n f o %
155% %
156% %
157% %
158%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
159%
160% AcquireRandomInfo() allocates the RandomInfo structure.
161%
162% The format of the AcquireRandomInfo method is:
163%
164% RandomInfo *AcquireRandomInfo(void)
165%
166*/
167MagickExport RandomInfo *AcquireRandomInfo(void)
168{
169 const StringInfo
170 *digest;
171
172 RandomInfo
173 *random_info;
174
175 StringInfo
176 *entropy,
177 *key,
178 *nonce;
179
180 random_info=(RandomInfo *) AcquireCriticalMemory(sizeof(*random_info));
181 (void) memset(random_info,0,sizeof(*random_info));
182 random_info->signature_info=AcquireSignatureInfo();
183 random_info->nonce=AcquireStringInfo(2*GetSignatureDigestsize(
184 random_info->signature_info));
185 ResetStringInfo(random_info->nonce);
186 random_info->reservoir=AcquireStringInfo(GetSignatureDigestsize(
187 random_info->signature_info));
188 ResetStringInfo(random_info->reservoir);
189 random_info->normalize=(double) (1.0/(MagickULLConstant(~0) >> 11));
190 random_info->seed[0]=MagickULLConstant(0x76e15d3efefdcbbf);
191 random_info->seed[1]=MagickULLConstant(0xc5004e441c522fb3);
192 random_info->seed[2]=MagickULLConstant(0x77710069854ee241);
193 random_info->seed[3]=MagickULLConstant(0x39109bb02acbe635);
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=GetMagickTime();
199 random_info->signature=MagickCoreSignature;
200 /*
201 Seed random nonce.
202 */
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);
214 /*
215 Seed random reservoir with entropic data.
216 */
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);
225 /*
226 Seed pseudo random number generator.
227 */
228 if (random_info->secret_key == ~0UL)
229 {
230 key=GetRandomKey(random_info,sizeof(random_info->seed));
231 (void) memcpy(random_info->seed,GetStringInfoDatum(key),
232 sizeof(random_info->seed));
233 key=DestroyStringInfo(key);
234 }
235 else
236 {
237 SignatureInfo
238 *signature_info;
239
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) memcpy(random_info->seed,GetStringInfoDatum(digest),
248 MagickMin((size_t) GetSignatureDigestsize(signature_info),
249 sizeof(random_info->seed)));
250 signature_info=DestroySignatureInfo(signature_info);
251 }
252 return(random_info);
253}
254␌
255/*
256%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
257% %
258% %
259% %
260+ D e s t r o y R a n d o m I n f o %
261% %
262% %
263% %
264%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
265%
266% DestroyRandomInfo() deallocates memory associated with the random
267% reservoir.
268%
269% The format of the DestroyRandomInfo method is:
270%
271% RandomInfo *DestroyRandomInfo(RandomInfo *random_info)
272%
273% A description of each parameter follows:
274%
275% o random_info: the random info.
276%
277*/
278MagickExport RandomInfo *DestroyRandomInfo(RandomInfo *random_info)
279{
280 assert(random_info != (RandomInfo *) NULL);
281 assert(random_info->signature == MagickCoreSignature);
282 if (IsEventLogging() != MagickFalse)
283 (void) LogMagickEvent(TraceEvent,GetMagickModule(),"...");
284 LockSemaphoreInfo(random_info->semaphore);
285 if (random_info->reservoir != (StringInfo *) NULL)
286 random_info->reservoir=DestroyStringInfo(random_info->reservoir);
287 if (random_info->nonce != (StringInfo *) NULL)
288 random_info->nonce=DestroyStringInfo(random_info->nonce);
289 if (random_info->signature_info != (SignatureInfo *) NULL)
290 random_info->signature_info=DestroySignatureInfo(
291 random_info->signature_info);
292 (void) memset(random_info->seed,0,sizeof(random_info->seed));
293 random_info->signature=(~MagickCoreSignature);
294 UnlockSemaphoreInfo(random_info->semaphore);
295 RelinquishSemaphoreInfo(&random_info->semaphore);
296 random_info=(RandomInfo *) RelinquishMagickMemory(random_info);
297 return(random_info);
298}
299␌
300/*
301%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
302% %
303% %
304% %
305+ G e n e r a t e E n t r o p i c C h a o s %
306% %
307% %
308% %
309%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
310%
311% GenerateEntropicChaos() generate entropic chaos used to initialize the
312% random reservoir.
313%
314% The format of the GenerateEntropicChaos method is:
315%
316% StringInfo *GenerateEntropicChaos(RandomInfo *random_info)
317%
318% A description of each parameter follows:
319%
320% o random_info: the random info.
321%
322*/
323
324#if !defined(MAGICKCORE_WINDOWS_SUPPORT)
325static ssize_t ReadRandom(int file,unsigned char *source,size_t length)
326{
327 unsigned char
328 *q;
329
330 ssize_t
331 offset,
332 count;
333
334 offset=0;
335 for (q=source; length != 0; length-=(size_t) count)
336 {
337 count=(ssize_t) read(file,q,length);
338 if (count <= 0)
339 {
340 count=0;
341 if (errno == EINTR)
342 continue;
343 return(-1);
344 }
345 q+=(ptrdiff_t) count;
346 offset+=count;
347 }
348 return(offset);
349}
350#endif
351
352static StringInfo *GenerateEntropicChaos(RandomInfo *random_info)
353{
354#define MaxEntropyExtent 64 /* max permitted: 256 */
355
356 MagickThreadType
357 tid;
358
359 StringInfo
360 *chaos,
361 *entropy;
362
363 ssize_t
364 pid;
365
366 time_t
367 nanoseconds,
368 seconds;
369
370 /*
371 Initialize random reservoir.
372 */
373 entropy=AcquireStringInfo(0);
374 LockSemaphoreInfo(random_info->semaphore);
375#if defined(MAGICKCORE_HAVE_GETENTROPY)
376 {
377 int
378 status;
379
380 SetStringInfoLength(entropy,MaxEntropyExtent);
381 status=getentropy(GetStringInfoDatum(entropy),MaxEntropyExtent);
382 if (status == 0)
383 {
384 UnlockSemaphoreInfo(random_info->semaphore);
385 return(entropy);
386 }
387 }
388#endif
389 chaos=AcquireStringInfo(sizeof(unsigned char *));
390 SetStringInfoDatum(chaos,(unsigned char *) &entropy);
391 ConcatenateStringInfo(entropy,chaos);
392 SetStringInfoDatum(chaos,(unsigned char *) entropy);
393 ConcatenateStringInfo(entropy,chaos);
394 pid=(ssize_t) getpid();
395 SetStringInfoLength(chaos,sizeof(pid));
396 SetStringInfoDatum(chaos,(unsigned char *) &pid);
397 ConcatenateStringInfo(entropy,chaos);
398 tid=GetMagickThreadId();
399 SetStringInfoLength(chaos,sizeof(tid));
400 SetStringInfoDatum(chaos,(unsigned char *) &tid);
401 ConcatenateStringInfo(entropy,chaos);
402#if defined(MAGICKCORE_HAVE_SYSCONF) && defined(_SC_PHYS_PAGES)
403 {
404 ssize_t
405 pages;
406
407 pages=(ssize_t) sysconf(_SC_PHYS_PAGES);
408 SetStringInfoLength(chaos,sizeof(pages));
409 SetStringInfoDatum(chaos,(unsigned char *) &pages);
410 ConcatenateStringInfo(entropy,chaos);
411 }
412#endif
413#if defined(MAGICKCORE_HAVE_GETRUSAGE) && defined(RUSAGE_SELF)
414 {
415 struct rusage
416 usage;
417
418 if (getrusage(RUSAGE_SELF,&usage) == 0)
419 {
420 SetStringInfoLength(chaos,sizeof(usage));
421 SetStringInfoDatum(chaos,(unsigned char *) &usage);
422 }
423 }
424#endif
425 seconds=time((time_t *) 0);
426 nanoseconds=0;
427#if defined(MAGICKCORE_HAVE_GETTIMEOFDAY)
428 {
429 struct timeval
430 timer;
431
432 if (gettimeofday(&timer,(struct timezone *) NULL) == 0)
433 {
434 seconds=timer.tv_sec;
435 nanoseconds=1000*timer.tv_usec;
436 }
437 }
438#endif
439#if defined(MAGICKCORE_HAVE_CLOCK_GETTIME) && defined(CLOCK_REALTIME_HR)
440 {
441 struct timespec
442 timer;
443
444 if (clock_gettime(CLOCK_REALTIME_HR,&timer) == 0)
445 {
446 seconds=timer.tv_sec;
447 nanoseconds=timer.tv_nsec;
448 }
449 }
450#endif
451 SetStringInfoLength(chaos,sizeof(seconds));
452 SetStringInfoDatum(chaos,(unsigned char *) &seconds);
453 ConcatenateStringInfo(entropy,chaos);
454 SetStringInfoLength(chaos,sizeof(nanoseconds));
455 SetStringInfoDatum(chaos,(unsigned char *) &nanoseconds);
456 ConcatenateStringInfo(entropy,chaos);
457 nanoseconds=0;
458#if defined(MAGICKCORE_HAVE_CLOCK)
459 nanoseconds=clock();
460#endif
461#if defined(MAGICKCORE_HAVE_TIMES)
462 {
463 struct tms
464 timer;
465
466 (void) times(&timer);
467 nanoseconds=timer.tms_utime+timer.tms_stime;
468 }
469#endif
470 SetStringInfoLength(chaos,sizeof(nanoseconds));
471 SetStringInfoDatum(chaos,(unsigned char *) &nanoseconds);
472 ConcatenateStringInfo(entropy,chaos);
473#if defined(MAGICKCORE_WINDOWS_SUPPORT)
474 {
475 double
476 nt_seconds;
477
478 LARGE_INTEGER
479 nt_nanoseconds;
480
481 /*
482 Not cryptographically strong but better than nothing.
483 */
484 nt_seconds=NTElapsedTime()+NTElapsedTime();
485 SetStringInfoLength(chaos,sizeof(nt_seconds));
486 SetStringInfoDatum(chaos,(unsigned char *) &nt_seconds);
487 ConcatenateStringInfo(entropy,chaos);
488 if (QueryPerformanceCounter(&nt_nanoseconds) != 0)
489 {
490 SetStringInfoLength(chaos,sizeof(nt_nanoseconds));
491 SetStringInfoDatum(chaos,(unsigned char *) &nt_nanoseconds);
492 ConcatenateStringInfo(entropy,chaos);
493 }
494 /*
495 Our best hope for true entropy.
496 */
497 SetStringInfoLength(chaos,MaxEntropyExtent);
498 (void) NTGatherRandomData(MaxEntropyExtent,GetStringInfoDatum(chaos));
499 ConcatenateStringInfo(entropy,chaos);
500 }
501#else
502 {
503 char
504 *filename;
505
506 int
507 file;
508
509 ssize_t
510 count;
511
512 StringInfo
513 *device;
514
515 /*
516 Not cryptographically strong but better than nothing.
517 */
518 if (environ != (char **) NULL)
519 {
520 ssize_t
521 i;
522
523 /*
524 Squeeze some entropy from the sometimes unpredictable environment.
525 */
526 for (i=0; environ[i] != (char *) NULL; i++)
527 {
528 SetStringInfoLength(chaos,strlen(environ[i]));
529 SetStringInfoDatum(chaos,(unsigned char *) environ[i]);
530 ConcatenateStringInfo(entropy,chaos);
531 }
532 }
533 filename=AcquireString("/dev/urandom");
534 device=StringToStringInfo(filename);
535 device=DestroyStringInfo(device);
536 file=open_utf8(filename,O_RDONLY | O_BINARY,0);
537 filename=DestroyString(filename);
538 if (file != -1)
539 {
540 SetStringInfoLength(chaos,MaxEntropyExtent);
541 count=ReadRandom(file,GetStringInfoDatum(chaos),MaxEntropyExtent);
542 (void) close_utf8(file);
543 SetStringInfoLength(chaos,(size_t) count);
544 ConcatenateStringInfo(entropy,chaos);
545 }
546 if (gather_true_random != MagickFalse)
547 {
548 /*
549 Our best hope for true entropy.
550 */
551 filename=AcquireString("/dev/random");
552 device=StringToStringInfo(filename);
553 device=DestroyStringInfo(device);
554 file=open_utf8(filename,O_RDONLY | O_BINARY,0);
555 filename=DestroyString(filename);
556 if (file == -1)
557 {
558 filename=AcquireString("/dev/srandom");
559 device=StringToStringInfo(filename);
560 device=DestroyStringInfo(device);
561 file=open_utf8(filename,O_RDONLY | O_BINARY,0);
562 }
563 if (file != -1)
564 {
565 SetStringInfoLength(chaos,MaxEntropyExtent);
566 count=ReadRandom(file,GetStringInfoDatum(chaos),MaxEntropyExtent);
567 (void) close_utf8(file);
568 SetStringInfoLength(chaos,(size_t) count);
569 ConcatenateStringInfo(entropy,chaos);
570 }
571 }
572 }
573#endif
574 chaos=DestroyStringInfo(chaos);
575 UnlockSemaphoreInfo(random_info->semaphore);
576 return(entropy);
577}
578␌
579/*
580%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
581% %
582% %
583% %
584% G e t P s e u d o R a n d o m V a l u e %
585% %
586% %
587% %
588%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
589%
590% GetPseudoRandomValue() is a Xoshiro generator that returns a non-negative
591% double-precision floating-point value uniformly distributed over the
592% interval [0.0, 1.0) with a 2 to the 256th-1 period.
593%
594% The format of the GetPseudoRandomValue method is:
595%
596% double GetPseudoRandomValue(RandomInfo *randon_info)
597%
598% A description of each parameter follows:
599%
600% o random_info: the random info.
601%
602*/
603MagickExport double GetPseudoRandomValue(
604 RandomInfo *magick_restrict random_info)
605{
606#define RandomROTL(x,k) (((x) << (k)) | ((x) >> (64-(k))))
607
608 const MagickSizeType
609 alpha = (random_info->seed[1] << 17),
610 value = (random_info->seed[0]+random_info->seed[3]);
611
612 random_info->seed[2]^=random_info->seed[0];
613 random_info->seed[3]^=random_info->seed[1];
614 random_info->seed[1]^=random_info->seed[2];
615 random_info->seed[0]^=random_info->seed[3];
616 random_info->seed[2]^=alpha;
617 random_info->seed[3]=RandomROTL(random_info->seed[3],45);
618 return((double) ((value >> 11)*random_info->normalize));
619}
620␌
621/*
622%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
623% %
624% %
625% %
626+ G e t R a n d o m I n f o N o r m a l i z e %
627% %
628% %
629% %
630%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
631%
632% GetRandomInfoNormalize() returns the random normalize value.
633%
634% The format of the GetRandomInfoNormalize method is:
635%
636% double GetRandomInfoNormalize(const RandomInfo *random_info)
637%
638% A description of each parameter follows:
639%
640% o random_info: the random info.
641%
642*/
643MagickPrivate double GetRandomInfoNormalize(const RandomInfo *random_info)
644{
645 assert(random_info != (const RandomInfo *) NULL);
646 return(random_info->normalize);
647}
648␌
649/*
650%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
651% %
652% %
653% %
654+ G e t R a n d o m I n f o S e e d %
655% %
656% %
657% %
658%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
659%
660% GetRandomInfoSeed() returns the random seed.
661%
662% The format of the GetRandomInfoSeed method is:
663%
664% unsigned long *GetRandomInfoSeed(RandomInfo *random_info)
665%
666% A description of each parameter follows:
667%
668% o random_info: the random info.
669%
670*/
671MagickPrivate unsigned long *GetRandomInfoSeed(RandomInfo *random_info)
672{
673 assert(random_info != (RandomInfo *) NULL);
674 return((unsigned long *) random_info->seed);
675}
676␌
677/*
678%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
679% %
680% %
681% %
682% G e t R a n d o m K e y %
683% %
684% %
685% %
686%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
687%
688% GetRandomKey() gets a random key from the reservoir.
689%
690% The format of the GetRandomKey method is:
691%
692% StringInfo *GetRandomKey(RandomInfo *random_info,const size_t length)
693%
694% A description of each parameter follows:
695%
696% o random_info: the random info.
697%
698% o length: the key length.
699%
700*/
701MagickExport StringInfo *GetRandomKey(RandomInfo *random_info,
702 const size_t length)
703{
704 StringInfo
705 *key;
706
707 assert(random_info != (RandomInfo *) NULL);
708 key=AcquireStringInfo(length);
709 SetRandomKey(random_info,length,GetStringInfoDatum(key));
710 return(key);
711}
712␌
713/*
714%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
715% %
716% %
717% %
718% G e t R a n d o m S e c r e t K e y %
719% %
720% %
721% %
722%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
723%
724% GetRandomSecretKey() returns the random secret key.
725%
726% The format of the GetRandomSecretKey method is:
727%
728% unsigned long GetRandomSecretKey(const RandomInfo *random_info)
729%
730% A description of each parameter follows:
731%
732% o random_info: the random info.
733*/
734MagickExport unsigned long GetRandomSecretKey(const RandomInfo *random_info)
735{
736 return(random_info->secret_key);
737}
738␌
739/*
740%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
741% %
742% %
743% %
744% G e t R a n d o m V a l u e %
745% %
746% %
747% %
748%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
749%
750% GetRandomValue() return a non-negative double-precision floating-point
751% value uniformly distributed over the interval [0.0, 1.0) with a 2 to the
752% 128th-1 period (not cryptographically strong).
753%
754% The format of the GetRandomValue method is:
755%
756% double GetRandomValue(void)
757%
758*/
759MagickExport double GetRandomValue(RandomInfo *random_info)
760{
761 unsigned long
762 key,
763 range;
764
765 range=(~0UL);
766 do
767 {
768 SetRandomKey(random_info,sizeof(key),(unsigned char *) &key);
769 } while (key == range);
770 return((double) key/range);
771}
772␌
773/*
774%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
775% %
776% %
777% %
778+ R a n d o m C o m p o n e n t G e n e s i s %
779% %
780% %
781% %
782%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
783%
784% RandomComponentGenesis() instantiates the random component.
785%
786% The format of the RandomComponentGenesis method is:
787%
788% MagickBooleanType RandomComponentGenesis(void)
789%
790*/
791MagickPrivate MagickBooleanType RandomComponentGenesis(void)
792{
793 if (random_semaphore == (SemaphoreInfo *) NULL)
794 random_semaphore=AcquireSemaphoreInfo();
795 return(MagickTrue);
796}
797␌
798/*
799%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
800% %
801% %
802% %
803+ R a n d o m C o m p o n e n t T e r m i n u s %
804% %
805% %
806% %
807%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
808%
809% RandomComponentTerminus() destroys the random component.
810%
811% The format of the RandomComponentTerminus method is:
812%
813% RandomComponentTerminus(void)
814%
815*/
816MagickPrivate void RandomComponentTerminus(void)
817{
818 if (random_semaphore == (SemaphoreInfo *) NULL)
819 ActivateSemaphoreInfo(&random_semaphore);
820 RelinquishSemaphoreInfo(&random_semaphore);
821}
822␌
823/*
824%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
825% %
826% %
827% %
828% S e t R a n d o m K e y %
829% %
830% %
831% %
832%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
833%
834% SetRandomKey() sets a random key from the reservoir.
835%
836% The format of the SetRandomKey method is:
837%
838% void SetRandomKey(RandomInfo *random_info,const size_t length,
839% unsigned char *key)
840%
841% A description of each parameter follows:
842%
843% o random_info: the random info.
844%
845% o length: the key length.
846%
847% o key: the key.
848%
849*/
850
851static inline void IncrementRandomNonce(StringInfo *nonce)
852{
853 ssize_t
854 i;
855
856 unsigned char
857 *datum;
858
859 datum=GetStringInfoDatum(nonce);
860 for (i=(ssize_t) (GetStringInfoLength(nonce)-1); i != 0; i--)
861 {
862 datum[i]++;
863 if (datum[i] != 0)
864 return;
865 }
866 ThrowFatalException(RandomFatalError,"SequenceWrapError");
867}
868
869MagickExport void SetRandomKey(RandomInfo *random_info,const size_t length,
870 unsigned char *key)
871{
872 size_t
873 i;
874
875 unsigned char
876 *p;
877
878 SignatureInfo
879 *signature_info;
880
881 unsigned char
882 *datum;
883
884 assert(random_info != (RandomInfo *) NULL);
885 if (length == 0)
886 return;
887 LockSemaphoreInfo(random_info->semaphore);
888 signature_info=random_info->signature_info;
889 datum=GetStringInfoDatum(random_info->reservoir);
890 i=length;
891 for (p=key; (i != 0) && (random_info->i != 0); i--)
892 {
893 *p++=datum[random_info->i];
894 random_info->i++;
895 if (random_info->i == GetSignatureDigestsize(signature_info))
896 random_info->i=0;
897 }
898 while (i >= GetSignatureDigestsize(signature_info))
899 {
900 InitializeSignature(signature_info);
901 UpdateSignature(signature_info,random_info->nonce);
902 FinalizeSignature(signature_info);
903 IncrementRandomNonce(random_info->nonce);
904 (void) memcpy(p,GetStringInfoDatum(GetSignatureDigest(
905 signature_info)),GetSignatureDigestsize(signature_info));
906 p+=(ptrdiff_t) GetSignatureDigestsize(signature_info);
907 i-=GetSignatureDigestsize(signature_info);
908 }
909 if (i != 0)
910 {
911 InitializeSignature(signature_info);
912 UpdateSignature(signature_info,random_info->nonce);
913 FinalizeSignature(signature_info);
914 IncrementRandomNonce(random_info->nonce);
915 SetStringInfo(random_info->reservoir,GetSignatureDigest(signature_info));
916 random_info->i=i;
917 datum=GetStringInfoDatum(random_info->reservoir);
918 while (i-- != 0)
919 p[i]=datum[i];
920 }
921 UnlockSemaphoreInfo(random_info->semaphore);
922}
923␌
924/*
925%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
926% %
927% %
928% %
929% S e t R a n d o m S e c r e t K e y %
930% %
931% %
932% %
933%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
934%
935% SetRandomSecretKey() sets the pseudo-random number generator secret key.
936%
937% The format of the SetRandomSecretKey method is:
938%
939% void SetRandomSecretKey(const unsigned long key)
940%
941% A description of each parameter follows:
942%
943% o key: the secret key.
944%
945*/
946MagickExport void SetRandomSecretKey(const unsigned long key)
947{
948 secret_key=key;
949}
950␌
951/*
952%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
953% %
954% %
955% %
956% S e t R a n d o m T r u e R a n d o m %
957% %
958% %
959% %
960%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
961%
962% SetRandomTrueRandom() declares your intentions to use true random numbers.
963% True random numbers are encouraged but may not always be practical because
964% your application may block while entropy is gathered from your environment.
965%
966% The format of the SetRandomTrueRandom method is:
967%
968% void SetRandomTrueRandom(const MagickBooleanType true_random)
969%
970% A description of each parameter follows:
971%
972% o true_random: declare your intentions to use true-random number.
973%
974*/
975MagickExport void SetRandomTrueRandom(const MagickBooleanType true_random)
976{
977 gather_true_random=true_random;
978}
_RandomInfo
Definition random.c:84