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);
246 silc_rng_xor(rng, getgid(), 4);
249 silc_rng_xor(rng, getpgrp(), 5);
252 silc_rng_xor(rng, getsid(getpid()) << 16, 6);
254 silc_rng_xor(rng, times(&ptime), 7);
255 silc_rng_xor(rng, ptime.tms_utime, 8);
256 silc_rng_xor(rng, (ptime.tms_utime + ptime.tms_stime), pos++);
257 silc_rng_xor(rng, (ptime.tms_stime + ptime.tms_cutime), pos++);
258 silc_rng_xor(rng, (ptime.tms_utime + ptime.tms_stime), pos++);
259 silc_rng_xor(rng, (ptime.tms_cutime ^ ptime.tms_stime), pos++);
260 silc_rng_xor(rng, (ptime.tms_cutime ^ ptime.tms_cstime), pos++);
261 silc_rng_xor(rng, (ptime.tms_utime ^ ptime.tms_stime), pos++);
262 silc_rng_xor(rng, (ptime.tms_stime ^ ptime.tms_cutime), pos++);
263 silc_rng_xor(rng, (ptime.tms_cutime + ptime.tms_stime), pos++);
264 silc_rng_xor(rng, (ptime.tms_stime << 8), pos++);
266 silc_rng_xor(rng, clock() << 4, pos++);
269 silc_rng_xor(rng, getpgid(getpid()) << 8, pos++);
272 silc_rng_xor(rng, getpgrp(), pos++);
275 silc_rng_xor(rng, getsid(getpid()) << 16, pos++);
277 silc_rng_xor(rng, times(&ptime), pos++);
278 silc_rng_xor(rng, ptime.tms_utime, pos++);
280 silc_rng_xor(rng, getpgrp(), pos++);
283 #ifdef HAVE_GETRUSAGE
284 getrusage(RUSAGE_SELF, &r);
285 silc_rng_xor(rng, (r.ru_utime.tv_sec + r.ru_utime.tv_usec), pos++);
286 silc_rng_xor(rng, (r.ru_utime.tv_sec ^ r.ru_utime.tv_usec), pos++);
287 silc_rng_xor(rng, (r.ru_stime.tv_sec + r.ru_stime.tv_usec), pos++);
288 silc_rng_xor(rng, (r.ru_stime.tv_sec ^ r.ru_stime.tv_usec), pos++);
290 silc_rng_xor(rng, (r.ru_maxrss + r.ru_ixrss), pos++);
291 silc_rng_xor(rng, (r.ru_maxrss ^ r.ru_ixrss), pos++);
292 silc_rng_xor(rng, (r.ru_idrss + r.ru_idrss), pos++);
293 silc_rng_xor(rng, (r.ru_idrss ^ r.ru_idrss), pos++);
294 silc_rng_xor(rng, (r.ru_idrss << 16), pos++);
295 silc_rng_xor(rng, (r.ru_minflt + r.ru_majflt), pos++);
296 silc_rng_xor(rng, (r.ru_minflt ^ r.ru_majflt), pos++);
297 silc_rng_xor(rng, (r.ru_nswap + r.ru_oublock + r.ru_inblock), pos++);
298 silc_rng_xor(rng, (r.ru_nswap << 8), pos++);
299 silc_rng_xor(rng, (r.ru_inblock + r.ru_oublock), pos++);
300 silc_rng_xor(rng, (r.ru_inblock ^ r.ru_oublock), pos++);
301 silc_rng_xor(rng, (r.ru_msgsnd ^ r.ru_msgrcv), pos++);
302 silc_rng_xor(rng, (r.ru_nsignals + r.ru_msgsnd + r.ru_msgrcv), pos++);
303 silc_rng_xor(rng, (r.ru_nsignals << 16), pos++);
304 silc_rng_xor(rng, (r.ru_nvcsw + r.ru_nivcsw), pos++);
305 silc_rng_xor(rng, (r.ru_nvcsw ^ r.ru_nivcsw), pos++);
306 #endif /* SILC_SYMBIAN */
309 #ifdef SILC_RNG_DEBUG
310 SILC_LOG_HEXDUMP(("pool"), rng->pool, sizeof(rng->pool));
313 /* Stir random pool */
314 silc_rng_stir_pool(rng);
317 /* This function gets noise from different commands */
319 static void silc_rng_get_medium_noise(SilcRng rng)
321 /* If getrusage is available, there is no need for shell commands */
322 #ifdef HAVE_GETRUSAGE
325 silc_rng_exec_command(rng, "ps -leaww 2> /dev/null");
326 silc_rng_exec_command(rng, "ls -afiln ~ 2> /dev/null");
327 silc_rng_exec_command(rng, "ls -afiln /proc 2> /dev/null");
328 silc_rng_exec_command(rng, "ps -axww 2> /dev/null");
330 #ifdef SILC_RNG_DEBUG
331 SILC_LOG_HEXDUMP(("pool"), rng->pool, sizeof(rng->pool));
335 /* This function gets 'hard' noise from environment. This tries to
336 get the noise from /dev/random if available. */
338 static void silc_rng_get_hard_noise(SilcRng rng)
340 #if defined(SILC_UNIX)
341 unsigned char buf[32];
344 /* Get noise from /dev/[u]random if available */
345 fd = open(rng->devrandom, O_RDONLY);
349 fcntl(fd, F_SETFL, O_NONBLOCK);
351 for (i = 0; i < 2; i++) {
352 len = read(fd, buf, sizeof(buf));
355 silc_rng_add_noise(rng, buf, len);
358 #ifdef SILC_RNG_DEBUG
359 SILC_LOG_HEXDUMP(("pool"), rng->pool, sizeof(rng->pool));
364 memset(buf, 0, sizeof(buf));
368 /* Execs command and gets noise from its output */
370 static void silc_rng_exec_command(SilcRng rng, char *command)
372 #if defined(SILC_UNIX)
373 unsigned char buf[1024];
379 fd = popen(command, "r");
383 /* Get data as much as we can get into the buffer */
384 for (i = 0; i < sizeof(buf); i++) {
394 /* Add the buffer into random pool */
395 silc_rng_add_noise(rng, buf, i);
396 memset(buf, 0, sizeof(buf));
401 /* This function adds the contents of the buffer as noise into random
402 pool. After adding the noise the pool is stirred. */
404 void silc_rng_add_noise(SilcRng rng, unsigned char *buffer, SilcUInt32 len)
408 pos = silc_rng_get_position(rng);
410 /* Add the buffer one by one into the pool */
411 for(i = 0; i < len; i++, buffer++) {
412 if(pos >= SILC_RNG_POOLSIZE)
414 rng->pool[pos++] ^= *buffer;
417 /* Stir random pool */
418 silc_rng_stir_pool(rng);
421 /* XOR's data into the pool */
423 static void silc_rng_xor(SilcRng rng, SilcUInt32 val, unsigned int pos)
427 SILC_GET32_MSB(tmp, &rng->pool[pos]);
429 SILC_PUT32_MSB(val, &rng->pool[pos]);
432 /* This function stirs the random pool by encrypting buffer in CFB
433 (cipher feedback) mode with SHA1 algorithm. */
435 static void silc_rng_stir_pool(SilcRng rng)
438 SilcUInt32 iv[5], tmp;
441 SILC_GET32_MSB(iv[0], &rng->pool[16 ]);
442 SILC_GET32_MSB(iv[1], &rng->pool[16 + 4]);
443 SILC_GET32_MSB(iv[2], &rng->pool[16 + 8]);
444 SILC_GET32_MSB(iv[3], &rng->pool[16 + 12]);
445 SILC_GET32_MSB(iv[4], &rng->pool[16 + 16]);
448 for (i = 0; i < SILC_RNG_POOLSIZE; i += 20) {
449 silc_hash_transform(rng->sha1, iv, rng->key);
451 SILC_GET32_MSB(tmp, &rng->pool[i]);
453 SILC_PUT32_MSB(iv[0], &rng->pool[i]);
455 SILC_GET32_MSB(tmp, &rng->pool[i + 4]);
457 SILC_PUT32_MSB(iv[1], &rng->pool[i + 4]);
459 SILC_GET32_MSB(tmp, &rng->pool[i + 8]);
461 SILC_PUT32_MSB(iv[2], &rng->pool[i + 8]);
463 SILC_GET32_MSB(tmp, &rng->pool[i + 12]);
465 SILC_PUT32_MSB(iv[3], &rng->pool[i + 12]);
467 SILC_GET32_MSB(tmp, &rng->pool[i + 16]);
469 SILC_PUT32_MSB(iv[4], &rng->pool[i + 16]);
473 memcpy(rng->key, &rng->pool[silc_rng_get_position(rng)], sizeof(rng->key));
475 /* Second CFB pass */
476 for (i = 0; i < SILC_RNG_POOLSIZE; i += 20) {
477 silc_hash_transform(rng->sha1, iv, rng->key);
479 SILC_GET32_MSB(tmp, &rng->pool[i]);
481 SILC_PUT32_MSB(iv[0], &rng->pool[i]);
483 SILC_GET32_MSB(tmp, &rng->pool[i + 4]);
485 SILC_PUT32_MSB(iv[1], &rng->pool[i + 4]);
487 SILC_GET32_MSB(tmp, &rng->pool[i + 8]);
489 SILC_PUT32_MSB(iv[2], &rng->pool[i + 8]);
491 SILC_GET32_MSB(tmp, &rng->pool[i + 12]);
493 SILC_PUT32_MSB(iv[3], &rng->pool[i + 12]);
495 SILC_GET32_MSB(tmp, &rng->pool[i + 16]);
497 SILC_PUT32_MSB(iv[4], &rng->pool[i + 16]);
500 memset(iv, 0, sizeof(iv));
503 /* Returns next position where data is fetched from the pool or
506 static SilcUInt32 silc_rng_get_position(SilcRng rng)
511 next = rng->state->next;
513 pos = rng->state->pos++;
514 if ((next->low != 0 && pos >= next->low) || (pos >= SILC_RNG_POOLSIZE))
515 rng->state->pos = rng->state->low;
517 #ifdef SILC_RNG_DEBUG
518 fprintf(stderr, "state: %p: low: %lu, pos: %lu\n",
519 rng->state, rng->state->low, rng->state->pos);
527 /* Returns random byte. */
529 SilcUInt8 silc_rng_get_byte(SilcRng rng)
535 /* Get more soft noise after 64 bits threshold */
536 if (rng->threshold >= 8)
537 silc_rng_get_soft_noise(rng);
539 /* Get hard noise after 160 bits threshold, zero the threshold. */
540 if (rng->threshold >= 20) {
542 silc_rng_get_hard_noise(rng);
545 do byte = rng->pool[silc_rng_get_position(rng)]; while (byte == 0x00);
549 /* Return random byte as fast as possible. Reads from /dev/urandom if
550 available. If not then return from normal RNG (not so fast). */
552 SilcUInt8 silc_rng_get_byte_fast(SilcRng rng)
554 #if defined(SILC_UNIX)
555 unsigned char buf[1];
557 if (rng->fd_devurandom == -1) {
558 rng->fd_devurandom = open("/dev/urandom", O_RDONLY);
559 if (rng->fd_devurandom < 0)
560 return silc_rng_get_byte(rng);
561 fcntl(rng->fd_devurandom, F_SETFL, O_NONBLOCK);
564 if (read(rng->fd_devurandom, buf, sizeof(buf)) < 0)
565 return silc_rng_get_byte(rng);
567 return buf[0] != 0x00 ? buf[0] : silc_rng_get_byte(rng);
569 return silc_rng_get_byte(rng);
573 /* Returns 16 bit random number */
575 SilcUInt16 silc_rng_get_rn16(SilcRng rng)
580 rn[0] = silc_rng_get_byte(rng);
581 rn[1] = silc_rng_get_byte(rng);
582 SILC_GET16_MSB(num, rn);
587 /* Returns 32 bit random number */
589 SilcUInt32 silc_rng_get_rn32(SilcRng rng)
594 rn[0] = silc_rng_get_byte(rng);
595 rn[1] = silc_rng_get_byte(rng);
596 rn[2] = silc_rng_get_byte(rng);
597 rn[3] = silc_rng_get_byte(rng);
598 SILC_GET32_MSB(num, rn);
603 /* Returns non-zero random number string. Returned string is in HEX format. */
605 unsigned char *silc_rng_get_rn_string(SilcRng rng, SilcUInt32 len)
608 unsigned char *string;
610 string = silc_calloc((len * 2 + 1), sizeof(unsigned char));
612 for (i = 0; i < len; i++)
613 sprintf(string + 2 * i, "%02x", silc_rng_get_byte(rng));
618 /* Returns non-zero random number binary data. */
620 unsigned char *silc_rng_get_rn_data(SilcRng rng, SilcUInt32 len)
625 data = silc_calloc(len + 1, sizeof(*data));
627 for (i = 0; i < len; i++)
628 data[i] = silc_rng_get_byte(rng);
633 /* Global RNG. This is global RNG that application can initialize so
634 that any part of code anywhere can use RNG without having to allocate
635 new RNG object everytime. If this is not initialized then these routines
636 will fail. Note: currently in SILC applications always initialize this. */
638 SilcRng global_rng = NULL;
640 /* Initialize global RNG. If `rng' is provided it is set as the global
641 RNG object (it can be allocated by the application for example). */
643 SilcBool silc_rng_global_init(SilcRng rng)
650 global_rng = silc_rng_alloc();
651 silc_rng_init(global_rng);
656 /* Uninitialize global RNG */
658 SilcBool silc_rng_global_uninit(void)
661 silc_rng_free(global_rng);
668 /* These are analogous to the functions above. */
670 SilcUInt8 silc_rng_global_get_byte(void)
672 return global_rng ? silc_rng_get_byte(global_rng) : 0;
675 /* Return random byte as fast as possible. Reads from /dev/urandom if
676 available. If not then return from normal RNG (not so fast). */
678 SilcUInt8 silc_rng_global_get_byte_fast(void)
680 return global_rng ? silc_rng_get_byte_fast(global_rng) : 0;
683 SilcUInt16 silc_rng_global_get_rn16(void)
685 return global_rng ? silc_rng_get_rn16(global_rng) : 0;
688 SilcUInt32 silc_rng_global_get_rn32(void)
690 return global_rng ? silc_rng_get_rn32(global_rng) : 0;
693 unsigned char *silc_rng_global_get_rn_string(SilcUInt32 len)
695 return global_rng ? silc_rng_get_rn_string(global_rng, len) : NULL;
698 unsigned char *silc_rng_global_get_rn_data(SilcUInt32 len)
700 return global_rng ? silc_rng_get_rn_data(global_rng, len) : NULL;
703 void silc_rng_global_add_noise(unsigned char *buffer, SilcUInt32 len)
706 silc_rng_add_noise(global_rng, buffer, len);