diff options
| -rw-r--r-- | sys/dev/rnd.c | 843 | ||||
| -rw-r--r-- | sys/dev/rndioctl.h | 56 | ||||
| -rw-r--r-- | sys/dev/rndvar.h | 58 |
3 files changed, 957 insertions, 0 deletions
diff --git a/sys/dev/rnd.c b/sys/dev/rnd.c new file mode 100644 index 00000000000..feae466d7bd --- /dev/null +++ b/sys/dev/rnd.c @@ -0,0 +1,843 @@ +/* $OpenBSD: rnd.c,v 1.1 1996/03/29 12:09:55 mickey Exp $ */ + +/* + * Copyright (c) 1996 Michael Shalayeff. + * + * This software derived from one contributed by Theodore Ts'o. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * This product includes software developed by Theodore Ts'o. + * 4. Neither the name of the University nor of the Laboratory may be used + * to endorse or promote products derived from this software without + * specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + * + * + * random.c -- A strong random number generator + * + * Version 0.96, last modified 29-Dec-95 + * + * Copyright Theodore Ts'o, 1994, 1995. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, and the entire permission notice in its entirety, + * including the disclaimer of warranties. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. The name of the author may not be used to endorse or promote + * products derived from this software without specific prior + * written permission. + * + * ALTERNATIVELY, this product may be distributed under the terms of + * the GNU Public License, in which case the provisions of the GPL are + * required INSTEAD OF the above restrictions. (This clause is + * necessary due to a potential bad interaction between the GPL and + * the restrictions contained in a BSD-style copyright.) + * + * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED + * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE + * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, + * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES + * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR + * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, + * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED + * OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +/* + * (now, with legal B.S. out of the way.....) + * + * This routine gathers environmental noise from device drivers, etc., + * and returns good random numbers, suitable for cryptographic use. + * Besides the obvious cryptographic uses, these numbers are also good + * for seeding TCP sequence numbers, and other places where it is + * desireable to have numbers which are not only random, but hard to + * predict by an attacker. + * + * Theory of operation + * =================== + * + * Computers are very predictable devices. Hence it is extremely hard + * to produce truely random numbers on a computer --- as opposed to + * pseudo-random numbers, which can easily generated by using a + * algorithm. Unfortunately, it is very easy for attackers to guess + * the sequence of pseudo-random number generators, and for some + * applications this is not acceptable. So instead, we must try to + * gather "environmental noise" from the computer's environment, which + * must be hard for outside attackers to observe, and use that to + * generate random numbers. In a Unix environment, this is best done + * from inside the kernel. + * + * Sources of randomness from the environment include inter-keyboard + * timings, inter-interrupt timings from some interrupts, and other + * events which are both (a) non-deterministic and (b) hard for an + * outside observer to measure. Randomness from these sources are + * added to an "entropy pool", which is mixed using a CRC-like function. + * This is not cryptographically strong, but it is adequate assuming + * the randomness is not chosen maliciously, and it is fast enough that + * the overhead of doing it on every interrupt is very reasonable. + * As random bytes are mixed into the entropy pool, the routines keep + * an *estimate* of how many bits of randomness have been stored into + * the random number generator's internal state. + * + * When random bytes are desired, they are obtained by taking the MD5 + * hash of the contents of the "entropy pool". The MD5 hash avoids + * exposing the internal state of the entropy pool. It is believed to + * be computationally infeasible to derive any useful information + * about the input of MD5 from its output. Even if it is possible to + * analyze MD5 in some clever way, as long as the amount of data + * returned from the generator is less than the inherent entropy in + * the pool, the output data is totally unpredictable. For this + * reason, the routine decreases its internal estimate of how many + * bits of "true randomness" are contained in the entropy pool as it + * outputs random numbers. + * + * If this estimate goes to zero, the routine can still generate + * random numbers; however, an attacker may (at least in theory) be + * able to infer the future output of the generator from prior + * outputs. This requires successful cryptanalysis of MD5, which is + * not believed to be feasible, but there is a remote possiblility. + * Nonetheless, these numbers should be useful for the vast majority + * of purposes. + * + * Exported interfaces ---- output + * =============================== + * + * There are three exported interfaces; the first is one designed to + * be used from within the kernel: + * + * void get_random_bytes(void *buf, int nbytes); + * + * This interface will return the requested number of random bytes, + * and place it in the requested buffer. + * + * The two other interfaces are two character devices /dev/random and + * /dev/urandom. /dev/random is suitable for use when very high + * quality randomness is desired (for example, for key generation or + * one-time pads), as it will only return a maximum of the number of + * bits of randomness (as estimated by the random number generator) + * contained in the entropy pool. + * + * The /dev/urandom device does not have this limit, and will return + * as many bytes as are requested. As more and more random bytes are + * requested without giving time for the entropy pool to recharge, + * this will result in random numbers that are merely cryptographically + * strong. For many applications, however, this is acceptable. + * + * Exported interfaces ---- input + * ============================== + * + * The current exported interfaces for gathering environmental noise + * from the devices are: + * + * void add_keyboard_randomness(u_char scancode); + * void add_mouse_randomness(u_int32_t mouse_data); + * void add_interrupt_randomness(int irq); + * void add_blkdev_randomness(dev_t dev); + * + * add_keyboard_randomness() uses the inter-keypress timing, as well as the + * scancode as random inputs into the "entropy pool". + * + * add_mouse_randomness() uses the mouse interrupt timing, as well as + * the reported position of the mouse from the hardware. + * + * add_interrupt_randomness() uses the inter-interrupt timing as random + * inputs to the entropy pool. Note that not all interrupts are good + * sources of randomness! For example, the timer interrupts is not a + * good choice, because the periodicity of the interrupts is to + * regular, and hence predictable to an attacker. Disk interrupts are + * a better measure, since the timing of the disk interrupts are more + * unpredictable. + * + * add_blkdev_randomness() times the finishing time of block requests. + * + * All of these routines try to estimate how many bits of randomness a + * particular randomness source. They do this by keeping track of the + * first and second order deltas of the event timings. + * + * Acknowledgements: + * ================= + * + * Ideas for constructing this random number generator were derived + * from the Pretty Good Privacy's random number generator, and from + * private discussions with Phil Karn. Colin Plumb provided a faster + * random number generator, which speed up the mixing function of the + * entropy pool, taken from PGP 3.0 (under development). It has since + * been modified by myself to provide better mixing in the case where + * the input values to add_entropy_word() are mostly small numbers. + * + * Any flaws in the design are solely my responsibility, and should + * not be attributed to the Phil, Colin, or any of authors of PGP. + * + * The code for MD5 transform was taken from Colin Plumb's + * implementation, which has been placed in the public domain. The + * MD5 cryptographic checksum was devised by Ronald Rivest, and is + * documented in RFC 1321, "The MD5 Message Digest Algorithm". + * + * Further background information on this topic may be obtained from + * RFC 1750, "Randomness Recommendations for Security", by Donald + * Eastlake, Steve Crocker, and Jeff Schiller. + */ + +#include "rnd.h" +#if NRND > 0 +#include <sys/param.h> +#include <sys/types.h> +#include <sys/systm.h> +#include <sys/kernel.h> +#include <sys/conf.h> +#include <sys/device.h> +#include <sys/ioctl.h> +#include <sys/malloc.h> +#include <sys/proc.h> +#include <sys/user.h> +#include <sys/fcntl.h> +#include <sys/vnode.h> + +#include <net/netisr.h> + +#include <dev/rndvar.h> +#include <dev/rndioctl.h> + +#ifdef DEBUG +int rnd_debug = 0x0000; +#define RD_INPUT 0x000f /* input data */ +#define RD_OUTPUT 0x00f0 /* output data */ +#define RD_WAIT 0x0100 /* sleep/wakeup for good data */ +#endif + +/* + * The pool is stirred with a primitive polynomial of degree 128 + * over GF(2), namely x^128 + x^99 + x^59 + x^31 + x^9 + x^7 + 1. + * For a pool of size 64, try x^64+x^62+x^38+x^10+x^6+x+1. + */ +#define POOLBITS (POOLWORDS*32) +#if POOLWORDS == 128 +#define TAP1 99 /* The polynomial taps */ +#define TAP2 59 +#define TAP3 31 +#define TAP4 9 +#define TAP5 7 +#elif POOLWORDS == 64 +#define TAP1 62 /* The polynomial taps */ +#define TAP2 38 +#define TAP3 10 +#define TAP4 6 +#define TAP5 1 +#else +#error No primitive polynomial available for chosen POOLWORDS +#endif + +/* There is actually only one of these, globally. */ +struct random_bucket { + u_int add_ptr; + u_int entropy_count; + int input_rotate; + u_int32_t *pool; +}; + +/* There is one of these per entropy source */ +struct timer_rand_state { + u_long last_time; + int last_delta; + int dont_count_entropy:1; +}; + +/* tags for different random sources */ +#define ENT_NET 0x100 +#define ENT_BLKDEV 0x200 +#define ENT_IRQ 0x300 + +/* device functions prototypes: XXX move em to dev_conf.h */ +cdev_decl(rnd); + +static struct random_bucket random_state; +static u_int32_t random_pool[POOLWORDS]; +static struct timer_rand_state keyboard_timer_state; +static struct timer_rand_state mouse_timer_state; +static struct timer_rand_state extract_timer_state; +static struct timer_rand_state net_timer_state[32]; /* XXX */ +static struct timer_rand_state *blkdev_timer_state; +static int rnd_sleep = 0; + +#ifndef MIN +#define MIN(a,b) (((a) < (b)) ? (a) : (b)) +#endif + +void +rndattach(num) + int num; +{ + if (num > 1) + panic("no more than one rnd device"); + + random_state.add_ptr = 0; + random_state.entropy_count = 0; + random_state.pool = random_pool; + blkdev_timer_state = malloc(nblkdev*sizeof(*blkdev_timer_state), + M_DEVBUF, M_WAITOK); + bzero(blkdev_timer_state, nblkdev*sizeof(*blkdev_timer_state)); + extract_timer_state.dont_count_entropy = 1; +} + +int +rndopen(dev, flag, mode, p) + dev_t dev; + int flag; + int mode; + struct proc *p; +{ + return 0; +} + +int +rndclose(dev, flag, mode, p) + dev_t dev; + int flag; + int mode; + struct proc *p; +{ + return 0; +} + +/* + * This function adds a byte into the entropy "pool". It does not + * update the entropy estimate. The caller must do this if appropriate. + * + * The pool is stirred with a primitive polynomial of degree 128 + * over GF(2), namely x^128 + x^99 + x^59 + x^31 + x^9 + x^7 + 1. + * For a pool of size 64, try x^64+x^62+x^38+x^10+x^6+x+1. + * + * We rotate the input word by a changing number of bits, to help + * assure that all bits in the entropy get toggled. Otherwise, if we + * consistently feed the entropy pool small numbers (like jiffies and + * scancodes, for example), the upper bits of the entropy pool don't + * get affected. --- TYT, 10/11/95 + */ +static inline void +add_entropy_word(r, input) + struct random_bucket *r; + const u_int32_t input; +{ + u_int i; + u_int32_t w; + + w = (input << r->input_rotate) | (input >> (32 - r->input_rotate)); + i = r->add_ptr = (r->add_ptr - 1) & (POOLWORDS-1); + if (i) + r->input_rotate = (r->input_rotate + 7) & 31; + else + /* + * At the beginning of the pool, add an extra 7 bits + * rotation, so that successive passes spread the + * input bits across the pool evenly. + */ + r->input_rotate = (r->input_rotate + 14) & 31; + + /* XOR in the various taps */ + w ^= r->pool[(i+TAP1)&(POOLWORDS-1)]; + w ^= r->pool[(i+TAP2)&(POOLWORDS-1)]; + w ^= r->pool[(i+TAP3)&(POOLWORDS-1)]; + w ^= r->pool[(i+TAP4)&(POOLWORDS-1)]; + w ^= r->pool[(i+TAP5)&(POOLWORDS-1)]; + w ^= r->pool[i]; + /* Rotate w left 1 bit (stolen from SHA) and store */ + r->pool[i] = (w << 1) | (w >> 31); +} + +/* + * This function adds entropy to the entropy "pool" by using timing + * delays. It uses the timer_rand_state structure to make an estimate + * of how many bits of entropy this call has added to the pool. + * + * The number "num" is also added to the pool - it should somehow describe + * the type of event which just happened. This is currently 0-255 for + * keyboard scan codes, and 256 upwards for interrupts. + * On the i386, this is assumed to be at most 16 bits, and the high bits + * are used for a high-resolution timer. + * + */ +static void +add_timer_randomness(r, state, num) + struct random_bucket *r; + struct timer_rand_state *state; + u_int num; +{ + int delta, delta2; + u_int nbits; + u_int32_t time; + + { + struct timeval tv; + microtime(&tv); + + time = tv.tv_usec ^ tv.tv_sec; + } + + add_entropy_word(r, (u_int32_t) num); + add_entropy_word(r, time); + + /* + * Calculate number of bits of randomness we probably + * added. We take into account the first and second order + * deltas in order to make our estimate. + */ + if (!state->dont_count_entropy) { + delta = time - state->last_time; + state->last_time = time; + + delta2 = delta - state->last_delta; + state->last_delta = delta; + + if (delta < 0) delta = -delta; + if (delta2 < 0) delta2 = -delta2; + delta = MIN(delta, delta2) >> 1; + for (nbits = 0; delta; nbits++) + delta >>= 1; + + r->entropy_count += nbits; + + /* Prevent overflow */ + if (r->entropy_count > POOLBITS) + r->entropy_count = POOLBITS; + } + + if (r->entropy_count > 8 && rnd_sleep != 0) { + rnd_sleep--; +#ifdef DEBUG + if (rnd_debug & RD_WAIT) + printf("rnd: wakeup[%d]{%u}\n", + rnd_sleep, r->entropy_count); +#endif + wakeup(&rnd_sleep); + } +} + +void +add_keyboard_randomness(scancode) + u_char scancode; +{ +#ifdef DEBUG + if (rnd_debug & RD_INPUT) + printf("rnd: adding %02x from kbd\n", scancode); +#endif + add_timer_randomness(&random_state, &keyboard_timer_state, scancode); +} + +void +add_mouse_randomness(mouse_data) + u_int32_t mouse_data; +{ + add_timer_randomness(&random_state, &mouse_timer_state, mouse_data); +} + +void +add_net_randomness(isr) + int isr; +{ + if (isr >= sizeof(net_timer_state)/sizeof(*net_timer_state)) + return; + + add_timer_randomness(&random_state, &net_timer_state[isr], + ENT_NET + isr); +} + +void +add_blkdev_randomness(dev) + dev_t dev; +{ + if (major(dev) >= nblkdev || blkdev_timer_state == NULL) + return; + + add_timer_randomness(&random_state, &blkdev_timer_state[major(dev)], + ENT_BLKDEV + major(dev)); +} + +/* + * MD5 transform algorithm, taken from code written by Colin Plumb, + * and put into the public domain + * + * QUESTION: Replace this with SHA, which as generally received better + * reviews from the cryptographic community? + */ + +/* The four core functions - F1 is optimized somewhat */ + +/* #define F1(x, y, z) (x & y | ~x & z) */ +#define F1(x, y, z) (z ^ (x & (y ^ z))) +#define F2(x, y, z) F1(z, x, y) +#define F3(x, y, z) (x ^ y ^ z) +#define F4(x, y, z) (y ^ (x | ~z)) + +/* This is the central step in the MD5 algorithm. */ +#define MD5STEP(f, w, x, y, z, data, s) \ + ( w += f(x, y, z) + data, w = w<<s | w>>(32-s), w += x ) + +/* + * The core of the MD5 algorithm, this alters an existing MD5 hash to + * reflect the addition of 16 longwords of new data. MD5Update blocks + * the data and converts bytes into longwords for this routine. + */ +static void +MD5Transform(buf, in) + u_int32_t buf[4]; + u_int32_t const in[16]; +{ + u_int32_t a, b, c, d; + + a = buf[0]; + b = buf[1]; + c = buf[2]; + d = buf[3]; + + MD5STEP(F1, a, b, c, d, in[ 0]+0xd76aa478, 7); + MD5STEP(F1, d, a, b, c, in[ 1]+0xe8c7b756, 12); + MD5STEP(F1, c, d, a, b, in[ 2]+0x242070db, 17); + MD5STEP(F1, b, c, d, a, in[ 3]+0xc1bdceee, 22); + MD5STEP(F1, a, b, c, d, in[ 4]+0xf57c0faf, 7); + MD5STEP(F1, d, a, b, c, in[ 5]+0x4787c62a, 12); + MD5STEP(F1, c, d, a, b, in[ 6]+0xa8304613, 17); + MD5STEP(F1, b, c, d, a, in[ 7]+0xfd469501, 22); + MD5STEP(F1, a, b, c, d, in[ 8]+0x698098d8, 7); + MD5STEP(F1, d, a, b, c, in[ 9]+0x8b44f7af, 12); + MD5STEP(F1, c, d, a, b, in[10]+0xffff5bb1, 17); + MD5STEP(F1, b, c, d, a, in[11]+0x895cd7be, 22); + MD5STEP(F1, a, b, c, d, in[12]+0x6b901122, 7); + MD5STEP(F1, d, a, b, c, in[13]+0xfd987193, 12); + MD5STEP(F1, c, d, a, b, in[14]+0xa679438e, 17); + MD5STEP(F1, b, c, d, a, in[15]+0x49b40821, 22); + + MD5STEP(F2, a, b, c, d, in[ 1]+0xf61e2562, 5); + MD5STEP(F2, d, a, b, c, in[ 6]+0xc040b340, 9); + MD5STEP(F2, c, d, a, b, in[11]+0x265e5a51, 14); + MD5STEP(F2, b, c, d, a, in[ 0]+0xe9b6c7aa, 20); + MD5STEP(F2, a, b, c, d, in[ 5]+0xd62f105d, 5); + MD5STEP(F2, d, a, b, c, in[10]+0x02441453, 9); + MD5STEP(F2, c, d, a, b, in[15]+0xd8a1e681, 14); + MD5STEP(F2, b, c, d, a, in[ 4]+0xe7d3fbc8, 20); + MD5STEP(F2, a, b, c, d, in[ 9]+0x21e1cde6, 5); + MD5STEP(F2, d, a, b, c, in[14]+0xc33707d6, 9); + MD5STEP(F2, c, d, a, b, in[ 3]+0xf4d50d87, 14); + MD5STEP(F2, b, c, d, a, in[ 8]+0x455a14ed, 20); + MD5STEP(F2, a, b, c, d, in[13]+0xa9e3e905, 5); + MD5STEP(F2, d, a, b, c, in[ 2]+0xfcefa3f8, 9); + MD5STEP(F2, c, d, a, b, in[ 7]+0x676f02d9, 14); + MD5STEP(F2, b, c, d, a, in[12]+0x8d2a4c8a, 20); + + MD5STEP(F3, a, b, c, d, in[ 5]+0xfffa3942, 4); + MD5STEP(F3, d, a, b, c, in[ 8]+0x8771f681, 11); + MD5STEP(F3, c, d, a, b, in[11]+0x6d9d6122, 16); + MD5STEP(F3, b, c, d, a, in[14]+0xfde5380c, 23); + MD5STEP(F3, a, b, c, d, in[ 1]+0xa4beea44, 4); + MD5STEP(F3, d, a, b, c, in[ 4]+0x4bdecfa9, 11); + MD5STEP(F3, c, d, a, b, in[ 7]+0xf6bb4b60, 16); + MD5STEP(F3, b, c, d, a, in[10]+0xbebfbc70, 23); + MD5STEP(F3, a, b, c, d, in[13]+0x289b7ec6, 4); + MD5STEP(F3, d, a, b, c, in[ 0]+0xeaa127fa, 11); + MD5STEP(F3, c, d, a, b, in[ 3]+0xd4ef3085, 16); + MD5STEP(F3, b, c, d, a, in[ 6]+0x04881d05, 23); + MD5STEP(F3, a, b, c, d, in[ 9]+0xd9d4d039, 4); + MD5STEP(F3, d, a, b, c, in[12]+0xe6db99e5, 11); + MD5STEP(F3, c, d, a, b, in[15]+0x1fa27cf8, 16); + MD5STEP(F3, b, c, d, a, in[ 2]+0xc4ac5665, 23); + + MD5STEP(F4, a, b, c, d, in[ 0]+0xf4292244, 6); + MD5STEP(F4, d, a, b, c, in[ 7]+0x432aff97, 10); + MD5STEP(F4, c, d, a, b, in[14]+0xab9423a7, 15); + MD5STEP(F4, b, c, d, a, in[ 5]+0xfc93a039, 21); + MD5STEP(F4, a, b, c, d, in[12]+0x655b59c3, 6); + MD5STEP(F4, d, a, b, c, in[ 3]+0x8f0ccc92, 10); + MD5STEP(F4, c, d, a, b, in[10]+0xffeff47d, 15); + MD5STEP(F4, b, c, d, a, in[ 1]+0x85845dd1, 21); + MD5STEP(F4, a, b, c, d, in[ 8]+0x6fa87e4f, 6); + MD5STEP(F4, d, a, b, c, in[15]+0xfe2ce6e0, 10); + MD5STEP(F4, c, d, a, b, in[ 6]+0xa3014314, 15); + MD5STEP(F4, b, c, d, a, in[13]+0x4e0811a1, 21); + MD5STEP(F4, a, b, c, d, in[ 4]+0xf7537e82, 6); + MD5STEP(F4, d, a, b, c, in[11]+0xbd3af235, 10); + MD5STEP(F4, c, d, a, b, in[ 2]+0x2ad7d2bb, 15); + MD5STEP(F4, b, c, d, a, in[ 9]+0xeb86d391, 21); + + buf[0] += a; + buf[1] += b; + buf[2] += c; + buf[3] += d; +} + +#undef F1 +#undef F2 +#undef F3 +#undef F4 +#undef MD5STEP + + +#if POOLWORDS % 16 +#error extract_entropy() assumes that POOLWORDS is a multiple of 16 words. +#endif +/* + * This function extracts randomness from the "entropy pool", and + * returns it in a buffer. This function computes how many remaining + * bits of entropy are left in the pool, but it does not restrict the + * number of bytes that are actually obtained. + */ +static inline int +extract_entropy(r, buf, nbytes) + struct random_bucket *r; + char *buf; + int nbytes; +{ + int ret, i; + u_int32_t tmp[4]; + + add_timer_randomness(r, &extract_timer_state, nbytes); + + /* Redundant, but just in case... */ + if (r->entropy_count > POOLBITS) + r->entropy_count = POOLBITS; + /* Why is this here? Left in from Ted Ts'o. Perhaps to limit time. */ + if (nbytes > 32768) + nbytes = 32768; + + ret = nbytes; + if (r->entropy_count / 8 >= nbytes) + r->entropy_count -= nbytes*8; + else + r->entropy_count = 0; + + while (nbytes) { + /* Hash the pool to get the output */ + tmp[0] = 0x67452301; + tmp[1] = 0xefcdab89; + tmp[2] = 0x98badcfe; + tmp[3] = 0x10325476; + for (i = 0; i < POOLWORDS; i += 16) + MD5Transform(tmp, r->pool+i); + /* Modify pool so next hash will produce different results */ + add_entropy_word(r, tmp[0]); + add_entropy_word(r, tmp[1]); + add_entropy_word(r, tmp[2]); + add_entropy_word(r, tmp[3]); + /* + * Run the MD5 Transform one more time, since we want + * to add at least minimal obscuring of the inputs to + * add_entropy_word(). --- TYT + */ + MD5Transform(tmp, r->pool); + + /* Copy data to destination buffer */ + i = MIN(nbytes, 16); + bcopy((caddr_t)tmp, buf, i); + nbytes -= i; + buf += i; + } + + /* Wipe data from memory */ + bzero(tmp, sizeof(tmp)); + + return ret; +} + +/* + * This function is the exported kernel interface. It returns some + * number of good random numbers, suitable for seeding TCP sequence + * numbers, etc. + */ +void +get_random_bytes(buf, nbytes) + void *buf; + size_t nbytes; +{ + extract_entropy(&random_state, (char *) buf, nbytes, 0); +} + +int +rndread(dev, uio, ioflag) + dev_t dev; + struct uio *uio; + int ioflag; +{ + int ret = 0; + int s; + + if (uio->uio_resid == 0) + return 0; + + while (!ret && uio->uio_resid > 0) { + u_int32_t buf[ POOLWORDS ]; + int n = min(sizeof(buf), uio->uio_resid); + + s = splhigh(); + switch(minor(dev)) + { + case RND_RND: + break; + case RND_SRND: + if (random_state.entropy_count < 8) { + if (ioflag & IO_NDELAY) { + ret = EWOULDBLOCK; + break; + } +#ifdef DEBUG + if (rnd_debug & RD_WAIT) + printf("rnd: sleep[%d]\n", + rnd_sleep); +#endif + rnd_sleep++; + ret = tsleep(&rnd_sleep, PWAIT | PCATCH, + "rndrd", 0); +#ifdef DEBUG + if (rnd_debug & RD_WAIT) + printf("rnd: awakened(%d)\n", + ret); +#endif + if (ret) + break; + } + n = min(n, random_state.entropy_count / 8); +#ifdef DEBUG + if (rnd_debug & RD_OUTPUT) + printf("rnd: %u possible output\n", + n ); +#endif + case RND_URND: + n = extract_entropy(&random_state, buf, n); +#ifdef DEBUG + if (rnd_debug & RD_OUTPUT) + printf("rnd: %u bytes for output\n", + n ); +#endif + break; + case RND_PRND: + { + int i = (n + 3) / 4; + while(i--) + buf[i] = random(); + } + break; + + } + splx(s); + if (n != 0 && ret == 0) + ret = uiomove((caddr_t)buf, n, uio); + } + + return ret; +} + +int +rndselect(dev, rw, p) + dev_t dev; + int rw; + struct proc *p; +{ + switch (rw) { + case FREAD: + return random_state.entropy_count > 0; + case FWRITE: + return 1; + } + + return 0; +} + +int +rndwrite(dev, uio, flags) + dev_t dev; + struct uio *uio; + int flags; +{ + int ret = 0; + + if (minor(dev) == RND_RND || minor(dev) == RND_PRND) + return ENXIO; + + if (uio->uio_resid == 0) + return 0; + + while (!ret && uio->uio_resid > 0) { + u_int32_t buf[ POOLWORDS ]; + u_short n = min(sizeof(buf),uio->uio_resid); + + ret = uiomove((caddr_t)buf, n, uio); + if (!ret) { + int i; + while (n % sizeof(u_int32_t)) + buf[n++] = 0; + for (i = 0; i < n; i++) + add_entropy_word(&random_state, buf[i]); + } + } + + return ret; +} + +int +rndioctl(dev, cmd, data, flag, p) + dev_t dev; + u_long cmd; + caddr_t data; + int flag; + struct proc *p; +{ + int ret; + + switch (cmd) { + + case RNDGETENTCNT: + ret = copyout(&random_state.entropy_count, data, + sizeof(random_state.entropy_count)); + break; + + case RNDADDTOENTCNT: + if (suser(p->p_ucred, &p->p_acflag) != 0) + return EPERM; + { + u_int cnt; + copyin(&cnt, data, sizeof(cnt)); + random_state.entropy_count += cnt; + } + if (random_state.entropy_count > POOLBITS) + random_state.entropy_count = POOLBITS; + break; + + case RNDZAPENTCNT: + if (suser(p->p_ucred, &p->p_acflag) != 0) + return EPERM; + random_state.entropy_count = 0; + break; + + default: + ret = EINVAL; + } + + return ret; +} +#endif diff --git a/sys/dev/rndioctl.h b/sys/dev/rndioctl.h new file mode 100644 index 00000000000..b50d233cf14 --- /dev/null +++ b/sys/dev/rndioctl.h @@ -0,0 +1,56 @@ +/* $OpenBSD: rndioctl.h,v 1.1 1996/03/29 12:09:57 mickey Exp $ */ + +/* + * Copyright (c) 1996 Michael Shalayeff. + * + * This software derived from one contributed by Theodore Ts'o. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * This product includes software developed by Theodore Ts'o. + * 4. Neither the name of the University nor of the Laboratory may be used + * to endorse or promote products derived from this software without + * specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + */ + + +#ifndef __RNDIOCTL_H__ +#define __RNDIOCTL_H__ + +struct rnd_pool_info { + size_t entropy_count; + size_t buf_size; + u_int32_t *buf; +}; + +/* ioctl()'s for the random number generator */ + +#define RNDGETENTCNT _IOR('R', 0, sizeof(u_int)) +#define RNDADDTOENTCNT _IOW('R', 1, sizeof(u_int)) +#define RNDGETPOOL _IOWR('R', 2, sizeof(struct rnd_pool_info)) +#define RNDADDENTROPY _IOW('R', 3, sizeof(u_int)) +#define RNDZAPENTCNT _IO( 'R', 4) + + +#endif /* __RNDIOCTL_H__ */ diff --git a/sys/dev/rndvar.h b/sys/dev/rndvar.h new file mode 100644 index 00000000000..44b37d98f0d --- /dev/null +++ b/sys/dev/rndvar.h @@ -0,0 +1,58 @@ +/* $OpenBSD: rndvar.h,v 1.1 1996/03/29 12:09:58 mickey Exp $ */ + +/* + * Copyright (c) 1996 Michael Shalayeff. + * + * This software derived from one contributed by Theodore Ts'o. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * This product includes software developed by Theodore Ts'o. + * 4. Neither the name of the University nor of the Laboratory may be used + * to endorse or promote products derived from this software without + * specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + */ + +#ifndef __RNDVAR_H__ +#define __RNDVAR_H__ + +#define POOLWORDS 128 /* Power of 2 - note that this is 32-bit words */ + +#define RND_RND 0 /* real randomness like nuclear chips */ +#define RND_SRND 1 /* strong random source */ +#define RND_URND 2 /* less strong random source */ +#define RND_PRND 3 /* pseudo random source */ + +#ifdef _KERNEL + +extern void add_keyboard_randomness __P((u_char)); +extern void add_mouse_randomness __P((u_int32_t)); +extern void add_net_randomness __P((int)); +extern void add_blkdev_randomness __P((dev_t)); + +extern void get_random_bytes __P((void *, size_t)); + +#endif /* _KERNEL */ + +#endif /* __RNDVAR_H__ */ |