5 Author: Pekka Riikonen <priikone@silcnet.org>
7 Copyright (C) 1997 - 2003 Pekka Riikonen
9 This program is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; version 2 of the License.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
21 * Created: Sun Mar 9 00:09:18 1997
23 * The original RNG was based on Secure Shell's random number generator
24 * by Tatu Ylönen and was used as reference when programming this RNG.
25 * This RNG has been rewritten twice since the creation.
32 extern pid_t getsid (pid_t __pid);
36 extern pid_t getpgid (pid_t __pid);
41 /*#define SILC_RNG_DEBUG*/
43 /* Number of states to fetch data from pool. */
44 #define SILC_RNG_STATE_NUM 4
46 /* Byte size of the random data pool. */
47 #define SILC_RNG_POOLSIZE (20 * 48)
49 static SilcUInt32 silc_rng_get_position(SilcRng rng);
50 static void silc_rng_stir_pool(SilcRng rng);
51 static void silc_rng_xor(SilcRng rng, SilcUInt32 val, unsigned int pos);
52 static void silc_rng_exec_command(SilcRng rng, char *command);
53 static void silc_rng_get_hard_noise(SilcRng rng);
54 static void silc_rng_get_medium_noise(SilcRng rng);
55 static void silc_rng_get_soft_noise(SilcRng rng);
58 SILC SilcRng State context.
60 This object is used by the random number generator to provide
61 variable points where the actual random number is fetched from
62 the random pool. This provides that the data is not fetched always
63 from the same point of the pool. Short description of the fields
69 The index for the random pool buffer. Lowest and current
72 SilcRngStateContext *next
74 Pointer to the next state. If this is the last state this
75 will point to the first state thus providing circular list.
78 typedef struct SilcRngStateContext {
81 struct SilcRngStateContext *next;
85 SILC Random Number Generator object.
87 This object holds random pool which is used to generate the random
88 numbers used by various routines needing cryptographically strong
89 random numbers. Following short descriptions of the fields.
93 The random pool. This buffer holds the random data. This is
94 frequently stirred thus providing ever changing randomnes.
98 Key used in stirring the random pool. The pool is encrypted
99 with SHA1 hash function in CFB (Cipher Feedback) mode.
101 SilcSilcRngState state
103 State object that is used to get the next position for the
104 random pool. This position is used to fetch data from pool
105 or to save the data to the pool. The state changes everytime
110 Hash object (SHA1) used to make the CFB encryption to the
111 random pool. This is allocated when RNG object is allocated and
112 free'd when RNG object is free'd.
116 Threshold to indicate when it is required to acquire more
117 noise from the environment. More soft noise is acquired after
118 64 bits of output and hard noise every 160 bits of output.
121 struct SilcRngStruct {
122 unsigned char pool[SILC_RNG_POOLSIZE];
123 unsigned char key[64];
131 /* Allocates new RNG object. */
133 SilcRng silc_rng_alloc(void)
137 SILC_LOG_DEBUG(("Allocating new RNG object"));
139 new = silc_calloc(1, sizeof(*new));
140 new->fd_devurandom = -1;
142 memset(new->pool, 0, sizeof(new->pool));
143 memset(new->key, 0, sizeof(new->key));
145 if (!silc_hash_alloc("sha1", &new->sha1)) {
147 SILC_LOG_ERROR(("Could not allocate sha1 hash, probably not registered"));
151 new->devrandom = strdup("/dev/random");
156 /* Free's RNG object. */
158 void silc_rng_free(SilcRng rng)
163 memset(rng->pool, 0, sizeof(rng->pool));
164 memset(rng->key, 0, sizeof(rng->key));
165 silc_hash_free(rng->sha1);
166 silc_free(rng->devrandom);
168 if (rng->fd_devurandom != -1)
169 close(rng->fd_devurandom);
171 for (t = rng->state->next; t != rng->state; ) {
176 silc_free(rng->state);
182 /* Initializes random number generator by getting noise from environment.
183 The environmental noise is our so called seed. One should not call
184 this function more than once. */
186 void silc_rng_init(SilcRng rng)
189 SilcRngState first, next;
193 SILC_LOG_DEBUG(("Initializing RNG object"));
195 /* Initialize the states for the RNG. */
196 rng->state = silc_calloc(1, sizeof(*rng->state));
199 rng->state->next = NULL;
201 for (i = SILC_RNG_STATE_NUM - 1; i >= 1; i--) {
202 next = silc_calloc(1, sizeof(*rng->state));
204 (i * (sizeof(rng->pool) / SILC_RNG_STATE_NUM));
206 (i * (sizeof(rng->pool) / SILC_RNG_STATE_NUM)) + 8;
207 next->next = rng->state;
213 memset(rng->pool, 0, sizeof(rng->pool));
215 /* Get noise from various environmental sources */
216 silc_rng_get_soft_noise(rng);
217 silc_rng_get_medium_noise(rng);
218 silc_rng_get_hard_noise(rng);
219 silc_rng_get_soft_noise(rng);
220 silc_free(rng->devrandom);
221 rng->devrandom = strdup("/dev/urandom");
224 /* This function gets 'soft' noise from environment. */
226 static void silc_rng_get_soft_noise(SilcRng rng)
232 #ifdef HAVE_GETRUSAGE
236 pos = silc_rng_get_position(rng);
238 silc_rng_xor(rng, clock(), 0);
241 silc_rng_xor(rng, getpid(), 1);
243 silc_rng_xor(rng, getpgid(getpid()) << 8, 2);
244 silc_rng_xor(rng, getpgid(getpid()) << 8, 3);
247 silc_rng_xor(rng, getgid(), 4);
251 silc_rng_xor(rng, getpgrp(), 5);
254 silc_rng_xor(rng, getsid(getpid()) << 16, 6);
257 silc_rng_xor(rng, times(&ptime), 7);
258 silc_rng_xor(rng, ptime.tms_utime, 8);
259 silc_rng_xor(rng, (ptime.tms_utime + ptime.tms_stime), pos++);
260 silc_rng_xor(rng, (ptime.tms_stime + ptime.tms_cutime), pos++);
261 silc_rng_xor(rng, (ptime.tms_utime + ptime.tms_stime), pos++);
262 silc_rng_xor(rng, (ptime.tms_cutime ^ ptime.tms_stime), pos++);
263 silc_rng_xor(rng, (ptime.tms_cutime ^ ptime.tms_cstime), pos++);
264 silc_rng_xor(rng, (ptime.tms_utime ^ ptime.tms_stime), pos++);
265 silc_rng_xor(rng, (ptime.tms_stime ^ ptime.tms_cutime), pos++);
266 silc_rng_xor(rng, (ptime.tms_cutime + ptime.tms_stime), pos++);
267 silc_rng_xor(rng, (ptime.tms_stime << 8), pos++);
268 #endif /* SILC_SYMBIAN */
270 silc_rng_xor(rng, clock() << 4, pos++);
273 silc_rng_xor(rng, getpgid(getpid()) << 8, pos++);
276 silc_rng_xor(rng, getpgrp(), pos++);
279 silc_rng_xor(rng, getsid(getpid()) << 16, pos++);
282 silc_rng_xor(rng, times(&ptime), pos++);
283 silc_rng_xor(rng, ptime.tms_utime, pos++);
284 #endif /* SILC_SYMBIAN */
286 silc_rng_xor(rng, getpgrp(), pos++);
289 #ifdef HAVE_GETRUSAGE
290 getrusage(RUSAGE_SELF, &r);
291 silc_rng_xor(rng, (r.ru_utime.tv_sec + r.ru_utime.tv_usec), pos++);
292 silc_rng_xor(rng, (r.ru_utime.tv_sec ^ r.ru_utime.tv_usec), pos++);
293 silc_rng_xor(rng, (r.ru_stime.tv_sec + r.ru_stime.tv_usec), pos++);
294 silc_rng_xor(rng, (r.ru_stime.tv_sec ^ r.ru_stime.tv_usec), pos++);
296 silc_rng_xor(rng, (r.ru_maxrss + r.ru_ixrss), pos++);
297 silc_rng_xor(rng, (r.ru_maxrss ^ r.ru_ixrss), pos++);
298 silc_rng_xor(rng, (r.ru_idrss + r.ru_idrss), pos++);
299 silc_rng_xor(rng, (r.ru_idrss ^ r.ru_idrss), pos++);
300 silc_rng_xor(rng, (r.ru_idrss << 16), pos++);
301 silc_rng_xor(rng, (r.ru_minflt + r.ru_majflt), pos++);
302 silc_rng_xor(rng, (r.ru_minflt ^ r.ru_majflt), pos++);
303 silc_rng_xor(rng, (r.ru_nswap + r.ru_oublock + r.ru_inblock), pos++);
304 silc_rng_xor(rng, (r.ru_nswap << 8), pos++);
305 silc_rng_xor(rng, (r.ru_inblock + r.ru_oublock), pos++);
306 silc_rng_xor(rng, (r.ru_inblock ^ r.ru_oublock), pos++);
307 silc_rng_xor(rng, (r.ru_msgsnd ^ r.ru_msgrcv), pos++);
308 silc_rng_xor(rng, (r.ru_nsignals + r.ru_msgsnd + r.ru_msgrcv), pos++);
309 silc_rng_xor(rng, (r.ru_nsignals << 16), pos++);
310 silc_rng_xor(rng, (r.ru_nvcsw + r.ru_nivcsw), pos++);
311 silc_rng_xor(rng, (r.ru_nvcsw ^ r.ru_nivcsw), pos++);
312 #endif /* SILC_SYMBIAN */
313 #endif /* HAVE_GETRUSAGE */
315 #ifdef SILC_RNG_DEBUG
316 SILC_LOG_HEXDUMP(("pool"), rng->pool, sizeof(rng->pool));
319 /* Stir random pool */
320 silc_rng_stir_pool(rng);
323 /* This function gets noise from different commands */
325 static void silc_rng_get_medium_noise(SilcRng rng)
327 /* If getrusage is available, there is no need for shell commands */
328 #ifdef HAVE_GETRUSAGE
331 silc_rng_exec_command(rng, "ps -leaww 2> /dev/null");
332 silc_rng_exec_command(rng, "ls -afiln ~ 2> /dev/null");
333 silc_rng_exec_command(rng, "ls -afiln /proc 2> /dev/null");
334 silc_rng_exec_command(rng, "ps -axww 2> /dev/null");
336 #ifdef SILC_RNG_DEBUG
337 SILC_LOG_HEXDUMP(("pool"), rng->pool, sizeof(rng->pool));
341 /* This function gets 'hard' noise from environment. This tries to
342 get the noise from /dev/random if available. */
344 static void silc_rng_get_hard_noise(SilcRng rng)
346 #if defined(SILC_UNIX)
347 unsigned char buf[32];
350 /* Get noise from /dev/[u]random if available */
351 fd = open(rng->devrandom, O_RDONLY);
355 fcntl(fd, F_SETFL, O_NONBLOCK);
357 for (i = 0; i < 2; i++) {
358 len = read(fd, buf, sizeof(buf));
361 silc_rng_add_noise(rng, buf, len);
364 #ifdef SILC_RNG_DEBUG
365 SILC_LOG_HEXDUMP(("pool"), rng->pool, sizeof(rng->pool));
370 memset(buf, 0, sizeof(buf));
374 /* Execs command and gets noise from its output */
376 static void silc_rng_exec_command(SilcRng rng, char *command)
378 #if defined(SILC_UNIX)
379 unsigned char buf[1024];
385 fd = popen(command, "r");
389 /* Get data as much as we can get into the buffer */
390 for (i = 0; i < sizeof(buf); i++) {
400 /* Add the buffer into random pool */
401 silc_rng_add_noise(rng, buf, i);
402 memset(buf, 0, sizeof(buf));
407 /* This function adds the contents of the buffer as noise into random
408 pool. After adding the noise the pool is stirred. */
410 void silc_rng_add_noise(SilcRng rng, unsigned char *buffer, SilcUInt32 len)
414 pos = silc_rng_get_position(rng);
416 /* Add the buffer one by one into the pool */
417 for(i = 0; i < len; i++, buffer++) {
418 if(pos >= SILC_RNG_POOLSIZE)
420 rng->pool[pos++] ^= *buffer;
423 /* Stir random pool */
424 silc_rng_stir_pool(rng);
427 /* XOR's data into the pool */
429 static void silc_rng_xor(SilcRng rng, SilcUInt32 val, unsigned int pos)
433 SILC_GET32_MSB(tmp, &rng->pool[pos]);
435 SILC_PUT32_MSB(val, &rng->pool[pos]);
438 /* This function stirs the random pool by encrypting buffer in CFB
439 (cipher feedback) mode with SHA1 algorithm. */
441 static void silc_rng_stir_pool(SilcRng rng)
444 SilcUInt32 iv[5], tmp;
447 SILC_GET32_MSB(iv[0], &rng->pool[16 ]);
448 SILC_GET32_MSB(iv[1], &rng->pool[16 + 4]);
449 SILC_GET32_MSB(iv[2], &rng->pool[16 + 8]);
450 SILC_GET32_MSB(iv[3], &rng->pool[16 + 12]);
451 SILC_GET32_MSB(iv[4], &rng->pool[16 + 16]);
454 for (i = 0; i < SILC_RNG_POOLSIZE; i += 20) {
455 silc_hash_transform(rng->sha1, iv, rng->key);
457 SILC_GET32_MSB(tmp, &rng->pool[i]);
459 SILC_PUT32_MSB(iv[0], &rng->pool[i]);
461 SILC_GET32_MSB(tmp, &rng->pool[i + 4]);
463 SILC_PUT32_MSB(iv[1], &rng->pool[i + 4]);
465 SILC_GET32_MSB(tmp, &rng->pool[i + 8]);
467 SILC_PUT32_MSB(iv[2], &rng->pool[i + 8]);
469 SILC_GET32_MSB(tmp, &rng->pool[i + 12]);
471 SILC_PUT32_MSB(iv[3], &rng->pool[i + 12]);
473 SILC_GET32_MSB(tmp, &rng->pool[i + 16]);
475 SILC_PUT32_MSB(iv[4], &rng->pool[i + 16]);
479 memcpy(rng->key, &rng->pool[silc_rng_get_position(rng)], sizeof(rng->key));
481 /* Second CFB pass */
482 for (i = 0; i < SILC_RNG_POOLSIZE; i += 20) {
483 silc_hash_transform(rng->sha1, iv, rng->key);
485 SILC_GET32_MSB(tmp, &rng->pool[i]);
487 SILC_PUT32_MSB(iv[0], &rng->pool[i]);
489 SILC_GET32_MSB(tmp, &rng->pool[i + 4]);
491 SILC_PUT32_MSB(iv[1], &rng->pool[i + 4]);
493 SILC_GET32_MSB(tmp, &rng->pool[i + 8]);
495 SILC_PUT32_MSB(iv[2], &rng->pool[i + 8]);
497 SILC_GET32_MSB(tmp, &rng->pool[i + 12]);
499 SILC_PUT32_MSB(iv[3], &rng->pool[i + 12]);
501 SILC_GET32_MSB(tmp, &rng->pool[i + 16]);
503 SILC_PUT32_MSB(iv[4], &rng->pool[i + 16]);
506 memset(iv, 0, sizeof(iv));
509 /* Returns next position where data is fetched from the pool or
512 static SilcUInt32 silc_rng_get_position(SilcRng rng)
517 next = rng->state->next;
519 pos = rng->state->pos++;
520 if ((next->low != 0 && pos >= next->low) || (pos >= SILC_RNG_POOLSIZE))
521 rng->state->pos = rng->state->low;
523 #ifdef SILC_RNG_DEBUG
524 fprintf(stderr, "state: %p: low: %lu, pos: %lu\n",
525 rng->state, rng->state->low, rng->state->pos);
533 /* Returns random byte. */
535 SilcUInt8 silc_rng_get_byte(SilcRng rng)
541 /* Get more soft noise after 64 bits threshold */
542 if (rng->threshold >= 8)
543 silc_rng_get_soft_noise(rng);
545 /* Get hard noise after 160 bits threshold, zero the threshold. */
546 if (rng->threshold >= 20) {
548 silc_rng_get_hard_noise(rng);
551 do byte = rng->pool[silc_rng_get_position(rng)]; while (byte == 0x00);
555 /* Return random byte as fast as possible. Reads from /dev/urandom if
556 available. If not then return from normal RNG (not so fast). */
558 SilcUInt8 silc_rng_get_byte_fast(SilcRng rng)
560 #if defined(SILC_UNIX)
561 unsigned char buf[1];
563 if (rng->fd_devurandom == -1) {
564 rng->fd_devurandom = open("/dev/urandom", O_RDONLY);
565 if (rng->fd_devurandom < 0)
566 return silc_rng_get_byte(rng);
567 fcntl(rng->fd_devurandom, F_SETFL, O_NONBLOCK);
570 if (read(rng->fd_devurandom, buf, sizeof(buf)) < 0)
571 return silc_rng_get_byte(rng);
573 return buf[0] != 0x00 ? buf[0] : silc_rng_get_byte(rng);
575 return silc_rng_get_byte(rng);
579 /* Returns 16 bit random number */
581 SilcUInt16 silc_rng_get_rn16(SilcRng rng)
586 rn[0] = silc_rng_get_byte(rng);
587 rn[1] = silc_rng_get_byte(rng);
588 SILC_GET16_MSB(num, rn);
593 /* Returns 32 bit random number */
595 SilcUInt32 silc_rng_get_rn32(SilcRng rng)
600 rn[0] = silc_rng_get_byte(rng);
601 rn[1] = silc_rng_get_byte(rng);
602 rn[2] = silc_rng_get_byte(rng);
603 rn[3] = silc_rng_get_byte(rng);
604 SILC_GET32_MSB(num, rn);
609 /* Returns non-zero random number string. Returned string is in HEX format. */
611 unsigned char *silc_rng_get_rn_string(SilcRng rng, SilcUInt32 len)
614 unsigned char *string;
616 string = silc_calloc((len * 2 + 1), sizeof(unsigned char));
618 for (i = 0; i < len; i++)
619 sprintf(string + 2 * i, "%02x", silc_rng_get_byte(rng));
624 /* Returns non-zero random number binary data. */
626 unsigned char *silc_rng_get_rn_data(SilcRng rng, SilcUInt32 len)
631 data = silc_calloc(len + 1, sizeof(*data));
633 for (i = 0; i < len; i++)
634 data[i] = silc_rng_get_byte(rng);
639 /* Global RNG. This is global RNG that application can initialize so
640 that any part of code anywhere can use RNG without having to allocate
641 new RNG object everytime. If this is not initialized then these routines
642 will fail. Note: currently in SILC applications always initialize this. */
644 SilcRng global_rng = NULL;
646 /* Initialize global RNG. If `rng' is provided it is set as the global
647 RNG object (it can be allocated by the application for example). */
649 SilcBool silc_rng_global_init(SilcRng rng)
656 global_rng = silc_rng_alloc();
657 silc_rng_init(global_rng);
662 /* Uninitialize global RNG */
664 SilcBool silc_rng_global_uninit(void)
667 silc_rng_free(global_rng);
674 /* These are analogous to the functions above. */
676 SilcUInt8 silc_rng_global_get_byte(void)
678 return global_rng ? silc_rng_get_byte(global_rng) : 0;
681 /* Return random byte as fast as possible. Reads from /dev/urandom if
682 available. If not then return from normal RNG (not so fast). */
684 SilcUInt8 silc_rng_global_get_byte_fast(void)
686 return global_rng ? silc_rng_get_byte_fast(global_rng) : 0;
689 SilcUInt16 silc_rng_global_get_rn16(void)
691 return global_rng ? silc_rng_get_rn16(global_rng) : 0;
694 SilcUInt32 silc_rng_global_get_rn32(void)
696 return global_rng ? silc_rng_get_rn32(global_rng) : 0;
699 unsigned char *silc_rng_global_get_rn_string(SilcUInt32 len)
701 return global_rng ? silc_rng_get_rn_string(global_rng, len) : NULL;
704 unsigned char *silc_rng_global_get_rn_data(SilcUInt32 len)
706 return global_rng ? silc_rng_get_rn_data(global_rng, len) : NULL;
709 void silc_rng_global_add_noise(unsigned char *buffer, SilcUInt32 len)
712 silc_rng_add_noise(global_rng, buffer, len);