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 1999-2019 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/semaphore.h"
57 #include "MagickCore/random_.h"
58 #include "MagickCore/random-private.h"
59 #include "MagickCore/resource_.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/utility.h"
65 #include "MagickCore/utility-private.h"
66 /*
67 Define declarations.
68 */
69 #define PseudoRandomHash SHA256Hash
70 #define RandomEntropyLevel 9
71 #define RandomFilename "reservoir.xdm"
72 #define RandomFiletype "random"
73 #define RandomProtocolMajorVersion 1
74 #define RandomProtocolMinorVersion 0
75
76 /*
77 Typedef declarations.
78 */
79 struct _RandomInfo
80 {
81 SignatureInfo
82 *signature_info;
83
84 StringInfo
85 *nonce,
86 *reservoir;
87
88 size_t
89 i;
90
91 unsigned long
92 seed[4];
93
94 double
95 normalize;
96
97 unsigned long
98 secret_key;
99
100 unsigned short
101 protocol_major,
102 protocol_minor;
103
104 SemaphoreInfo
105 *semaphore;
106
107 ssize_t
108 timestamp;
109
110 size_t
111 signature;
112 };
113
114 /*
115 External declarations.
116 */
117 #if defined(__APPLE__) && !defined(TARGET_OS_IPHONE)
118 #include <crt_externs.h>
119 #define environ (*_NSGetEnviron())
120 #endif
121
122 #if !defined(MAGICKCORE_WINDOWS_SUPPORT)
123 extern char
124 **environ;
125 #endif
126
127 /*
128 Global declarations.
129 */
130 static SemaphoreInfo
131 *random_semaphore = (SemaphoreInfo *) NULL;
132
133 static unsigned long
134 secret_key = ~0UL;
135
136 static MagickBooleanType
137 gather_true_random = MagickFalse;
138
139 /*
140 Forward declarations.
141 */
142 static StringInfo
143 *GenerateEntropicChaos(RandomInfo *);
144
145 /*
146 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
147 % %
148 % %
149 % %
150 % A c q u i r e R a n d o m I n f o %
151 % %
152 % %
153 % %
154 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
155 %
156 % AcquireRandomInfo() allocates the RandomInfo structure.
157 %
158 % The format of the AcquireRandomInfo method is:
159 %
160 % RandomInfo *AcquireRandomInfo(void)
161 %
162 */
163
AcquireRandomInfo(void)164 MagickExport RandomInfo *AcquireRandomInfo(void)
165 {
166 const StringInfo
167 *digest;
168
169 RandomInfo
170 *random_info;
171
172 StringInfo
173 *entropy,
174 *key,
175 *nonce;
176
177 random_info=(RandomInfo *) AcquireCriticalMemory(sizeof(*random_info));
178 (void) memset(random_info,0,sizeof(*random_info));
179 random_info->signature_info=AcquireSignatureInfo();
180 random_info->nonce=AcquireStringInfo(2*GetSignatureDigestsize(
181 random_info->signature_info));
182 ResetStringInfo(random_info->nonce);
183 random_info->reservoir=AcquireStringInfo(GetSignatureDigestsize(
184 random_info->signature_info));
185 ResetStringInfo(random_info->reservoir);
186 random_info->normalize=1.0/(~0UL);
187 random_info->secret_key=secret_key;
188 random_info->protocol_major=RandomProtocolMajorVersion;
189 random_info->protocol_minor=RandomProtocolMinorVersion;
190 random_info->semaphore=AcquireSemaphoreInfo();
191 random_info->timestamp=(ssize_t) time(0);
192 random_info->signature=MagickCoreSignature;
193 /*
194 Seed random nonce.
195 */
196 nonce=GenerateEntropicChaos(random_info);
197 if (nonce == (StringInfo *) NULL)
198 ThrowFatalException(ResourceLimitFatalError,"MemoryAllocationFailed");
199 InitializeSignature(random_info->signature_info);
200 UpdateSignature(random_info->signature_info,nonce);
201 FinalizeSignature(random_info->signature_info);
202 SetStringInfoLength(nonce,(GetSignatureDigestsize(
203 random_info->signature_info)+1)/2);
204 SetStringInfo(nonce,GetSignatureDigest(random_info->signature_info));
205 SetStringInfo(random_info->nonce,nonce);
206 nonce=DestroyStringInfo(nonce);
207 /*
208 Seed random reservoir with entropic data.
209 */
210 entropy=GenerateEntropicChaos(random_info);
211 if (entropy == (StringInfo *) NULL)
212 ThrowFatalException(ResourceLimitFatalError,"MemoryAllocationFailed");
213 UpdateSignature(random_info->signature_info,entropy);
214 FinalizeSignature(random_info->signature_info);
215 SetStringInfo(random_info->reservoir,GetSignatureDigest(
216 random_info->signature_info));
217 entropy=DestroyStringInfo(entropy);
218 /*
219 Seed pseudo random number generator.
220 */
221 if (random_info->secret_key == ~0UL)
222 {
223 key=GetRandomKey(random_info,sizeof(random_info->secret_key));
224 (void) memcpy(random_info->seed,GetStringInfoDatum(key),
225 GetStringInfoLength(key));
226 key=DestroyStringInfo(key);
227 }
228 else
229 {
230 SignatureInfo
231 *signature_info;
232
233 signature_info=AcquireSignatureInfo();
234 key=AcquireStringInfo(sizeof(random_info->secret_key));
235 SetStringInfoDatum(key,(unsigned char *) &random_info->secret_key);
236 UpdateSignature(signature_info,key);
237 key=DestroyStringInfo(key);
238 FinalizeSignature(signature_info);
239 digest=GetSignatureDigest(signature_info);
240 (void) memcpy(random_info->seed,GetStringInfoDatum(digest),
241 MagickMin(GetSignatureDigestsize(signature_info),
242 sizeof(*random_info->seed)));
243 signature_info=DestroySignatureInfo(signature_info);
244 }
245 random_info->seed[1]=0x50a7f451UL;
246 random_info->seed[2]=0x5365417eUL;
247 random_info->seed[3]=0xc3a4171aUL;
248 return(random_info);
249 }
250
251 /*
252 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
253 % %
254 % %
255 % %
256 + D e s t r o y R a n d o m I n f o %
257 % %
258 % %
259 % %
260 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
261 %
262 % DestroyRandomInfo() deallocates memory associated with the random
263 % reservoir.
264 %
265 % The format of the DestroyRandomInfo method is:
266 %
267 % RandomInfo *DestroyRandomInfo(RandomInfo *random_info)
268 %
269 % A description of each parameter follows:
270 %
271 % o random_info: the random info.
272 %
273 */
DestroyRandomInfo(RandomInfo * random_info)274 MagickExport RandomInfo *DestroyRandomInfo(RandomInfo *random_info)
275 {
276 (void) LogMagickEvent(TraceEvent,GetMagickModule(),"...");
277 assert(random_info != (RandomInfo *) NULL);
278 assert(random_info->signature == MagickCoreSignature);
279 LockSemaphoreInfo(random_info->semaphore);
280 if (random_info->reservoir != (StringInfo *) NULL)
281 random_info->reservoir=DestroyStringInfo(random_info->reservoir);
282 if (random_info->nonce != (StringInfo *) NULL)
283 random_info->nonce=DestroyStringInfo(random_info->nonce);
284 if (random_info->signature_info != (SignatureInfo *) NULL)
285 random_info->signature_info=DestroySignatureInfo(
286 random_info->signature_info);
287 (void) memset(random_info->seed,0,sizeof(random_info->seed));
288 random_info->signature=(~MagickCoreSignature);
289 UnlockSemaphoreInfo(random_info->semaphore);
290 RelinquishSemaphoreInfo(&random_info->semaphore);
291 random_info=(RandomInfo *) RelinquishMagickMemory(random_info);
292 return(random_info);
293 }
294
295 /*
296 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
297 % %
298 % %
299 % %
300 + G e n e r a t e E n t r o p i c C h a o s %
301 % %
302 % %
303 % %
304 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
305 %
306 % GenerateEntropicChaos() generate entropic chaos used to initialize the
307 % random reservoir.
308 %
309 % The format of the GenerateEntropicChaos method is:
310 %
311 % StringInfo *GenerateEntropicChaos(RandomInfo *random_info)
312 %
313 % A description of each parameter follows:
314 %
315 % o random_info: the random info.
316 %
317 */
318
319 #if !defined(MAGICKCORE_WINDOWS_SUPPORT)
ReadRandom(int file,unsigned char * source,size_t length)320 static ssize_t ReadRandom(int file,unsigned char *source,size_t length)
321 {
322 register unsigned char
323 *q;
324
325 ssize_t
326 offset,
327 count;
328
329 offset=0;
330 for (q=source; length != 0; length-=count)
331 {
332 count=(ssize_t) read(file,q,length);
333 if (count <= 0)
334 {
335 count=0;
336 if (errno == EINTR)
337 continue;
338 return(-1);
339 }
340 q+=count;
341 offset+=count;
342 }
343 return(offset);
344 }
345 #endif
346
GenerateEntropicChaos(RandomInfo * random_info)347 static StringInfo *GenerateEntropicChaos(RandomInfo *random_info)
348 {
349 #define MaxEntropyExtent 64
350
351 MagickThreadType
352 tid;
353
354 StringInfo
355 *chaos,
356 *entropy;
357
358 size_t
359 nanoseconds,
360 seconds;
361
362 ssize_t
363 pid;
364
365 /*
366 Initialize random reservoir.
367 */
368 entropy=AcquireStringInfo(0);
369 LockSemaphoreInfo(random_info->semaphore);
370 chaos=AcquireStringInfo(sizeof(unsigned char *));
371 SetStringInfoDatum(chaos,(unsigned char *) &entropy);
372 ConcatenateStringInfo(entropy,chaos);
373 SetStringInfoDatum(chaos,(unsigned char *) entropy);
374 ConcatenateStringInfo(entropy,chaos);
375 pid=(ssize_t) getpid();
376 SetStringInfoLength(chaos,sizeof(pid));
377 SetStringInfoDatum(chaos,(unsigned char *) &pid);
378 ConcatenateStringInfo(entropy,chaos);
379 tid=GetMagickThreadId();
380 SetStringInfoLength(chaos,sizeof(tid));
381 SetStringInfoDatum(chaos,(unsigned char *) &tid);
382 ConcatenateStringInfo(entropy,chaos);
383 #if defined(MAGICKCORE_HAVE_SYSCONF) && defined(_SC_PHYS_PAGES)
384 {
385 ssize_t
386 pages;
387
388 pages=(ssize_t) sysconf(_SC_PHYS_PAGES);
389 SetStringInfoLength(chaos,sizeof(pages));
390 SetStringInfoDatum(chaos,(unsigned char *) &pages);
391 ConcatenateStringInfo(entropy,chaos);
392 }
393 #endif
394 #if defined(MAGICKCORE_HAVE_GETRUSAGE) && defined(RUSAGE_SELF)
395 {
396 struct rusage
397 usage;
398
399 if (getrusage(RUSAGE_SELF,&usage) == 0)
400 {
401 SetStringInfoLength(chaos,sizeof(usage));
402 SetStringInfoDatum(chaos,(unsigned char *) &usage);
403 }
404 }
405 #endif
406 seconds=time((time_t *) 0);
407 nanoseconds=0;
408 #if defined(MAGICKCORE_HAVE_GETTIMEOFDAY)
409 {
410 struct timeval
411 timer;
412
413 if (gettimeofday(&timer,(struct timezone *) NULL) == 0)
414 {
415 seconds=timer.tv_sec;
416 nanoseconds=1000UL*timer.tv_usec;
417 }
418 }
419 #endif
420 #if defined(MAGICKCORE_HAVE_CLOCK_GETTIME) && defined(CLOCK_REALTIME_HR)
421 {
422 struct timespec
423 timer;
424
425 if (clock_gettime(CLOCK_REALTIME_HR,&timer) == 0)
426 {
427 seconds=timer.tv_sec;
428 nanoseconds=timer.tv_nsec;
429 }
430 }
431 #endif
432 SetStringInfoLength(chaos,sizeof(seconds));
433 SetStringInfoDatum(chaos,(unsigned char *) &seconds);
434 ConcatenateStringInfo(entropy,chaos);
435 SetStringInfoLength(chaos,sizeof(nanoseconds));
436 SetStringInfoDatum(chaos,(unsigned char *) &nanoseconds);
437 ConcatenateStringInfo(entropy,chaos);
438 nanoseconds=0;
439 #if defined(MAGICKCORE_HAVE_CLOCK)
440 nanoseconds=clock();
441 #endif
442 #if defined(MAGICKCORE_HAVE_TIMES)
443 {
444 struct tms
445 timer;
446
447 (void) times(&timer);
448 nanoseconds=timer.tms_utime+timer.tms_stime;
449 }
450 #endif
451 SetStringInfoLength(chaos,sizeof(nanoseconds));
452 SetStringInfoDatum(chaos,(unsigned char *) &nanoseconds);
453 ConcatenateStringInfo(entropy,chaos);
454 #if defined(MAGICKCORE_HAVE_MKSTEMP)
455 {
456 char
457 path[MagickPathExtent];
458
459 int
460 file;
461
462 (void) strcpy(path,"XXXXXX");
463 file=mkstemp(path);
464 if (file != -1)
465 {
466 #if defined(MAGICKCORE_HAVE_FCHMOD)
467 (void) fchmod(file,0600);
468 #endif
469 #if defined(__OS2__)
470 setmode(file,O_BINARY);
471 #endif
472 (void) close(file);
473 }
474 (void) remove_utf8(path);
475 SetStringInfoLength(chaos,strlen(path));
476 SetStringInfoDatum(chaos,(unsigned char *) path);
477 ConcatenateStringInfo(entropy,chaos);
478 }
479 #endif
480 #if defined(MAGICKCORE_WINDOWS_SUPPORT)
481 {
482 double
483 datum;
484
485 LARGE_INTEGER
486 datum1;
487
488 /*
489 Not crytographically strong but better than nothing.
490 */
491 datum=NTElapsedTime()+NTUserTime();
492 SetStringInfoLength(chaos,sizeof(datum));
493 SetStringInfoDatum(chaos,(unsigned char *) &datum);
494 ConcatenateStringInfo(entropy,chaos);
495 if (QueryPerformanceCounter(&datum1) != 0)
496 {
497 SetStringInfoLength(chaos,sizeof(datum1));
498 SetStringInfoDatum(chaos,(unsigned char *) &datum1);
499 ConcatenateStringInfo(entropy,chaos);
500 }
501 /*
502 Our best hope for true entropy.
503 */
504 SetStringInfoLength(chaos,MaxEntropyExtent);
505 (void) NTGatherRandomData(MaxEntropyExtent,GetStringInfoDatum(chaos));
506 ConcatenateStringInfo(entropy,chaos);
507 }
508 #else
509 {
510 char
511 *filename;
512
513 int
514 file;
515
516 ssize_t
517 count;
518
519 StringInfo
520 *device;
521
522 /*
523 Not crytographically strong but better than nothing.
524 */
525 if (environ != (char **) NULL)
526 {
527 register ssize_t
528 i;
529
530 /*
531 Squeeze some entropy from the sometimes unpredicatble environment.
532 */
533 for (i=0; environ[i] != (char *) NULL; i++)
534 {
535 SetStringInfoLength(chaos,strlen(environ[i]));
536 SetStringInfoDatum(chaos,(unsigned char *) environ[i]);
537 ConcatenateStringInfo(entropy,chaos);
538 }
539 }
540 filename=AcquireString("/dev/urandom");
541 device=StringToStringInfo(filename);
542 device=DestroyStringInfo(device);
543 file=open_utf8(filename,O_RDONLY | O_BINARY,0);
544 filename=DestroyString(filename);
545 if (file != -1)
546 {
547 SetStringInfoLength(chaos,MaxEntropyExtent);
548 count=ReadRandom(file,GetStringInfoDatum(chaos),MaxEntropyExtent);
549 (void) close(file);
550 SetStringInfoLength(chaos,(size_t) count);
551 ConcatenateStringInfo(entropy,chaos);
552 }
553 if (gather_true_random != MagickFalse)
554 {
555 /*
556 Our best hope for true entropy.
557 */
558 filename=AcquireString("/dev/random");
559 device=StringToStringInfo(filename);
560 device=DestroyStringInfo(device);
561 file=open_utf8(filename,O_RDONLY | O_BINARY,0);
562 filename=DestroyString(filename);
563 if (file == -1)
564 {
565 filename=AcquireString("/dev/srandom");
566 device=StringToStringInfo(filename);
567 device=DestroyStringInfo(device);
568 file=open_utf8(filename,O_RDONLY | O_BINARY,0);
569 }
570 if (file != -1)
571 {
572 SetStringInfoLength(chaos,MaxEntropyExtent);
573 count=ReadRandom(file,GetStringInfoDatum(chaos),MaxEntropyExtent);
574 (void) close(file);
575 SetStringInfoLength(chaos,(size_t) count);
576 ConcatenateStringInfo(entropy,chaos);
577 }
578 }
579 }
580 #endif
581 chaos=DestroyStringInfo(chaos);
582 UnlockSemaphoreInfo(random_info->semaphore);
583 return(entropy);
584 }
585
586 /*
587 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
588 % %
589 % %
590 % %
591 % G e t P s e u d o R a n d o m V a l u e %
592 % %
593 % %
594 % %
595 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
596 %
597 % GetPseudoRandomValue() return a non-negative double-precision floating-point
598 % value uniformly distributed over the interval [0.0, 1.0) with a 2 to the
599 % 128th-1 period.
600 %
601 % The format of the GetPseudoRandomValue method is:
602 %
603 % double GetPseudoRandomValue(RandomInfo *randon_info)
604 %
605 % A description of each parameter follows:
606 %
607 % o random_info: the random info.
608 %
609 */
GetPseudoRandomValue(RandomInfo * random_info)610 MagickExport double GetPseudoRandomValue(RandomInfo *random_info)
611 {
612 register unsigned long
613 *seed;
614
615 unsigned long
616 alpha;
617
618 seed=random_info->seed;
619 do
620 {
621 alpha=(unsigned long) (seed[1] ^ (seed[1] << 11));
622 seed[1]=seed[2];
623 seed[2]=seed[3];
624 seed[3]=seed[0];
625 seed[0]=(seed[0] ^ (seed[0] >> 19)) ^ (alpha ^ (alpha >> 8));
626 } while (seed[0] == ~0UL);
627 return(random_info->normalize*seed[0]);
628 }
629
630 /*
631 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
632 % %
633 % %
634 % %
635 + G e t R a n d o m I n f o N o r m a l i z e %
636 % %
637 % %
638 % %
639 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
640 %
641 % GetRandomInfoNormalize() returns the random normalize value.
642 %
643 % The format of the GetRandomInfoNormalize method is:
644 %
645 % double GetRandomInfoNormalize(const RandomInfo *random_info)
646 %
647 % A description of each parameter follows:
648 %
649 % o random_info: the random info.
650 %
651 */
GetRandomInfoNormalize(const RandomInfo * random_info)652 MagickPrivate double GetRandomInfoNormalize(const RandomInfo *random_info)
653 {
654 assert(random_info != (const RandomInfo *) NULL);
655 return(random_info->normalize);
656 }
657
658 /*
659 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
660 % %
661 % %
662 % %
663 + G e t R a n d o m I n f o S e e d %
664 % %
665 % %
666 % %
667 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
668 %
669 % GetRandomInfoSeed() returns the random seed.
670 %
671 % The format of the GetRandomInfoSeed method is:
672 %
673 % unsigned long *GetRandomInfoSeed(RandomInfo *random_info)
674 %
675 % A description of each parameter follows:
676 %
677 % o random_info: the random info.
678 %
679 */
GetRandomInfoSeed(RandomInfo * random_info)680 MagickPrivate unsigned long *GetRandomInfoSeed(RandomInfo *random_info)
681 {
682 assert(random_info != (RandomInfo *) NULL);
683 return(random_info->seed);
684 }
685
686 /*
687 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
688 % %
689 % %
690 % %
691 % G e t R a n d o m K e y %
692 % %
693 % %
694 % %
695 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
696 %
697 % GetRandomKey() gets a random key from the reservoir.
698 %
699 % The format of the GetRandomKey method is:
700 %
701 % StringInfo *GetRandomKey(RandomInfo *random_info,const size_t length)
702 %
703 % A description of each parameter follows:
704 %
705 % o random_info: the random info.
706 %
707 % o length: the key length.
708 %
709 */
GetRandomKey(RandomInfo * random_info,const size_t length)710 MagickExport StringInfo *GetRandomKey(RandomInfo *random_info,
711 const size_t length)
712 {
713 StringInfo
714 *key;
715
716 assert(random_info != (RandomInfo *) NULL);
717 key=AcquireStringInfo(length);
718 SetRandomKey(random_info,length,GetStringInfoDatum(key));
719 return(key);
720 }
721
722 /*
723 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
724 % %
725 % %
726 % %
727 % G e t R a n d o m S e c r e t K e y %
728 % %
729 % %
730 % %
731 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
732 %
733 % GetRandomSecretKey() returns the random secet key.
734 %
735 % The format of the GetRandomSecretKey method is:
736 %
737 % unsigned long GetRandomSecretKey(const RandomInfo *random_info)
738 %
739 % A description of each parameter follows:
740 %
741 % o random_info: the random info.
742 */
GetRandomSecretKey(const RandomInfo * random_info)743 MagickExport unsigned long GetRandomSecretKey(const RandomInfo *random_info)
744 {
745 return(random_info->secret_key);
746 }
747
748 /*
749 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
750 % %
751 % %
752 % %
753 % G e t R a n d o m V a l u e %
754 % %
755 % %
756 % %
757 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
758 %
759 % GetRandomValue() return a non-negative double-precision floating-point
760 % value uniformly distributed over the interval [0.0, 1.0) with a 2 to the
761 % 128th-1 period (not cryptographically strong).
762 %
763 % The format of the GetRandomValue method is:
764 %
765 % double GetRandomValue(void)
766 %
767 */
GetRandomValue(RandomInfo * random_info)768 MagickExport double GetRandomValue(RandomInfo *random_info)
769 {
770 unsigned long
771 key,
772 range;
773
774 range=(~0UL);
775 do
776 {
777 SetRandomKey(random_info,sizeof(key),(unsigned char *) &key);
778 } while (key == range);
779 return((double) key/range);
780 }
781
782 /*
783 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
784 % %
785 % %
786 % %
787 + R a n d o m C o m p o n e n t G e n e s i s %
788 % %
789 % %
790 % %
791 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
792 %
793 % RandomComponentGenesis() instantiates the random component.
794 %
795 % The format of the RandomComponentGenesis method is:
796 %
797 % MagickBooleanType RandomComponentGenesis(void)
798 %
799 */
RandomComponentGenesis(void)800 MagickPrivate MagickBooleanType RandomComponentGenesis(void)
801 {
802 if (random_semaphore == (SemaphoreInfo *) NULL)
803 random_semaphore=AcquireSemaphoreInfo();
804 return(MagickTrue);
805 }
806
807 /*
808 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
809 % %
810 % %
811 % %
812 + R a n d o m C o m p o n e n t T e r m i n u s %
813 % %
814 % %
815 % %
816 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
817 %
818 % RandomComponentTerminus() destroys the random component.
819 %
820 % The format of the RandomComponentTerminus method is:
821 %
822 % RandomComponentTerminus(void)
823 %
824 */
RandomComponentTerminus(void)825 MagickPrivate void RandomComponentTerminus(void)
826 {
827 if (random_semaphore == (SemaphoreInfo *) NULL)
828 ActivateSemaphoreInfo(&random_semaphore);
829 RelinquishSemaphoreInfo(&random_semaphore);
830 }
831
832 /*
833 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
834 % %
835 % %
836 % %
837 % S e t R a n d o m K e y %
838 % %
839 % %
840 % %
841 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
842 %
843 % SetRandomKey() sets a random key from the reservoir.
844 %
845 % The format of the SetRandomKey method is:
846 %
847 % void SetRandomKey(RandomInfo *random_info,const size_t length,
848 % unsigned char *key)
849 %
850 % A description of each parameter follows:
851 %
852 % o random_info: the random info.
853 %
854 % o length: the key length.
855 %
856 % o key: the key.
857 %
858 */
859
IncrementRandomNonce(StringInfo * nonce)860 static inline void IncrementRandomNonce(StringInfo *nonce)
861 {
862 register ssize_t
863 i;
864
865 unsigned char
866 *datum;
867
868 datum=GetStringInfoDatum(nonce);
869 for (i=(ssize_t) (GetStringInfoLength(nonce)-1); i != 0; i--)
870 {
871 datum[i]++;
872 if (datum[i] != 0)
873 return;
874 }
875 ThrowFatalException(RandomFatalError,"SequenceWrapError");
876 }
877
SetRandomKey(RandomInfo * random_info,const size_t length,unsigned char * key)878 MagickExport void SetRandomKey(RandomInfo *random_info,const size_t length,
879 unsigned char *key)
880 {
881 register size_t
882 i;
883
884 register unsigned char
885 *p;
886
887 SignatureInfo
888 *signature_info;
889
890 unsigned char
891 *datum;
892
893 assert(random_info != (RandomInfo *) NULL);
894 if (length == 0)
895 return;
896 LockSemaphoreInfo(random_info->semaphore);
897 signature_info=random_info->signature_info;
898 datum=GetStringInfoDatum(random_info->reservoir);
899 i=length;
900 for (p=key; (i != 0) && (random_info->i != 0); i--)
901 {
902 *p++=datum[random_info->i];
903 random_info->i++;
904 if (random_info->i == GetSignatureDigestsize(signature_info))
905 random_info->i=0;
906 }
907 while (i >= GetSignatureDigestsize(signature_info))
908 {
909 InitializeSignature(signature_info);
910 UpdateSignature(signature_info,random_info->nonce);
911 FinalizeSignature(signature_info);
912 IncrementRandomNonce(random_info->nonce);
913 (void) memcpy(p,GetStringInfoDatum(GetSignatureDigest(
914 signature_info)),GetSignatureDigestsize(signature_info));
915 p+=GetSignatureDigestsize(signature_info);
916 i-=GetSignatureDigestsize(signature_info);
917 }
918 if (i != 0)
919 {
920 InitializeSignature(signature_info);
921 UpdateSignature(signature_info,random_info->nonce);
922 FinalizeSignature(signature_info);
923 IncrementRandomNonce(random_info->nonce);
924 SetStringInfo(random_info->reservoir,GetSignatureDigest(signature_info));
925 random_info->i=i;
926 datum=GetStringInfoDatum(random_info->reservoir);
927 while (i-- != 0)
928 p[i]=datum[i];
929 }
930 UnlockSemaphoreInfo(random_info->semaphore);
931 }
932
933 /*
934 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
935 % %
936 % %
937 % %
938 % S e t R a n d o m S e c r e t K e y %
939 % %
940 % %
941 % %
942 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
943 %
944 % SetRandomSecretKey() sets the pseudo-random number generator secret key.
945 %
946 % The format of the SetRandomSecretKey method is:
947 %
948 % void SetRandomSecretKey(const unsigned long key)
949 %
950 % A description of each parameter follows:
951 %
952 % o key: the secret seed.
953 %
954 */
SetRandomSecretKey(const unsigned long key)955 MagickExport void SetRandomSecretKey(const unsigned long key)
956 {
957 secret_key=key;
958 }
959
960 /*
961 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
962 % %
963 % %
964 % %
965 % S e t R a n d o m T r u e R a n d o m %
966 % %
967 % %
968 % %
969 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
970 %
971 % SetRandomTrueRandom() declares your intentions to use true random numbers.
972 % True random numbers are encouraged but may not always be practical because
973 % your application may block while entropy is gathered from your environment.
974 %
975 % The format of the SetRandomTrueRandom method is:
976 %
977 % void SetRandomTrueRandom(const MagickBooleanType true_random)
978 %
979 % A description of each parameter follows:
980 %
981 % o true_random: declare your intentions to use true-random number.
982 %
983 */
SetRandomTrueRandom(const MagickBooleanType true_random)984 MagickExport void SetRandomTrueRandom(const MagickBooleanType true_random)
985 {
986 gather_true_random=true_random;
987 }
988