Unfortunately, I'm not using 1.3.33 regularly, since the new device
initialization code broke PCMCIA network access. (I'll be sending in a
bug report about that shortly). But I've tested things pretty
thoroughly, and the random driver should be producing signficantly
better results as well as having a lower system overhead.
Cheers!
- Ted
===================================================================
RCS file: RCS/MAGIC,v
retrieving revision 1.1
diff -u -r1.1 MAGIC
--- MAGIC 1995/10/11 18:40:13 1.1
+++ MAGIC 1995/10/11 18:40:44
@@ -50,6 +50,7 @@
Ioctl Include File Comments
========================================================
0x00 fd.h
+0x01 random.h subcodes starting at 0x080000
0x03 hdreg.h
0x06 lp.h
0x12 fs.h
===================================================================
RCS file: drivers/char/RCS/random.c,v
retrieving revision 1.1
diff -u -r1.1 drivers/char/random.c
--- drivers/char/random.c 1995/10/11 12:25:25 1.1
+++ drivers/char/random.c 1995/10/13 15:25:02
@@ -1,7 +1,7 @@
/*
* random.c -- A strong random number generator
*
- * Version 0.92, last modified 21-Sep-95
+ * Version 0.94, last modified 11-Oct-95
*
* Copyright Theodore Ts'o, 1994, 1995. All rights reserved.
*
@@ -65,34 +65,33 @@
* 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 periodically mixed using the
- * MD5 compression function in CBC mode. 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.
+ * 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 a counter plus the contents of the "entropy pool". The
- * reason for the MD5 hash is so that we can avoid exposing the
- * internal state of random number generator. Although the MD5 hash
- * does protect the pool, as each random byte which is generated from
- * the pool reveals some information which was derived from the
- * internal state, and thus increasing the amount of information an
- * outside attacker has available to try to make some guesses about
- * the random number generator's internal state. 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 it may now be possible for an attacker to analyze
- * the output of the random number generator, and the MD5 algorithm,
- * and thus have some success in guessing the output of the routine.
- * Phil Karn (who devised this mechanism of using MD5 plus a counter
- * to extract random numbers from an entropy pool) calls this
- * "practical randomness", since in the worse case this is equivalent
- * to hashing MD5 with a counter and an undisclosed secret. If MD5 is
- * a strong cryptographic hash, this should be fairly resistant to attack.
+ * 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
* ===============================
@@ -107,47 +106,61 @@
*
* 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.),
- * 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.
+ * 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 lower quality random numbers. For many
- * applications, however, this is acceptable.
+ * this will result in random numbers that are merely cryptographically
+ * strong. For many applications, however, this is acceptable.
*
* Exported interfaces ---- input
* ==============================
- *
- * The two current exported interfaces for gathering environmental
- * noise from the devices are:
+ *
+ * The current exported interfaces for gathering environmental noise
+ * from the devices are:
*
* void add_keyboard_randomness(unsigned char scancode);
+ * void add_mouse_randomness(__u32 mouse_data);
* void add_interrupt_randomness(int irq);
+ * void add_blkdev_randomness(int irq);
*
- * The first function uses the inter-keypress timing, as well as the
+ * 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.
*
- * The second function uses the inter-interrupt timing as random
+ * 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. The routines try to estimate how many bits of
- * randomness a particular interrupt channel offers, by keeping track
- * of the first and second order deltas in the interrupt timings.
+ * 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. This design has been further
- * modified by myself, so any flaws are solely my responsibility, and
- * should not be attributed to the authors of PGP or to Phil.
+ * 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
@@ -159,31 +172,50 @@
* Eastlake, Steve Crocker, and Jeff Schiller.
*/
-#ifdef linux
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/major.h>
#include <linux/string.h>
+#include <linux/fcntl.h>
+#include <linux/malloc.h>
#include <linux/random.h>
#include <asm/segment.h>
#include <asm/irq.h>
#include <asm/io.h>
-#endif
-#ifdef CONFIG_RANDOM
-
-#define RANDPOOL 512
+/*
+ * The pool is stirred with a primitive polynomial of degree 128
+ * over GF(2), namely x^128 + x^119 + x^72 + x^64 + x^14 + x^8 + 1.
+ * For a pool of size 64, try x^64+x^62+x^38+x^10+x^6+x+1.
+ */
+#define POOLWORDS 128 /* Power of 2 - note that this is 32-bit words */
+#define POOLBITS (POOLWORDS*32)
+#if POOLWORDS == 128
+#define TAP1 119 /* The polynomial taps */
+#define TAP2 72
+#define TAP3 64
+#define TAP4 14
+#define TAP5 8
+#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 {
- int add_ptr;
- int entropy_count;
- int length;
- int bit_length;
- int delay_mix:1;
- __u8 *pool;
+ unsigned add_ptr;
+ unsigned entropy_count;
+ int input_rotate;
+ __u32 *pool;
};
+/* There is one of these per entropy source */
struct timer_rand_state {
unsigned long last_time;
int last_delta;
@@ -191,34 +223,206 @@
};
static struct random_bucket random_state;
-static __u32 rand_pool_key[16];
-static __u8 random_pool[RANDPOOL];
-static __u32 random_counter[16];
+static __u32 random_pool[POOLWORDS];
static struct timer_rand_state keyboard_timer_state;
-static struct timer_rand_state irq_timer_state[NR_IRQS];
+static struct timer_rand_state mouse_timer_state;
+static struct timer_rand_state extract_timer_state;
+static struct timer_rand_state *irq_timer_state[NR_IRQS];
+static struct timer_rand_state *blkdev_timer_state[MAX_BLKDEV];
+static struct wait_queue *random_wait;
#ifndef MIN
#define MIN(a,b) (((a) < (b)) ? (a) : (b))
#endif
-static void flush_random(struct random_bucket *random_state)
+void rand_initialize(void)
+{
+ random_state.add_ptr = 0;
+ random_state.entropy_count = 0;
+ random_state.pool = random_pool;
+ memset(irq_timer_state, 0, sizeof(irq_timer_state));
+ memset(blkdev_timer_state, 0, sizeof(blkdev_timer_state));
+ random_wait = NULL;}
+
+void rand_initialize_irq(int irq)
{
- random_state->add_ptr = 0;
- random_state->bit_length = random_state->length * 8;
- random_state->entropy_count = 0;
- random_state->delay_mix = 0;
+ if (irq >= NR_IRQS || irq_timer_state[irq])
+ return;
+
+ /*
+ * If kamlloc returns null, we just won't use that entropy
+ * source.
+ */
+ irq_timer_state[irq] = kmalloc(sizeof(struct timer_rand_state),
+ GFP_KERNEL);
}
-void rand_initialize(void)
+void rand_initialize_blkdev(int major)
{
- random_state.length = RANDPOOL;
- random_state.pool = random_pool;
- flush_random(&random_state);
+ if (major >= MAX_BLKDEV || blkdev_timer_state[major])
+ return;
+
+ /*
+ * If kamlloc returns null, we just won't use that entropy
+ * source.
+ */
+ blkdev_timer_state[major] = kmalloc(sizeof(struct timer_rand_state),
+ GFP_KERNEL);
+}
+
+/*
+ * 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^119 + x^72 + x^64 + x^14 + x^8 + 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(struct random_bucket *r,
+ const __u32 input)
+{
+ unsigned i;
+ __u32 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.
+ *
+ * TODO: Read the time stamp register on the Pentium.
+ */
+static void add_timer_randomness(struct random_bucket *r,
+ struct timer_rand_state *state, unsigned num)
+{
+ int delta, delta2;
+ unsigned nbits;
+ __u32 time;
+
+#if defined (__i386__)
+ if (x86_capability & 16) {
+ unsigned long low, high;
+ __asm__(".byte 0x0f,0x31"
+ :"=a" (low), "=d" (high));
+ time = (__u32) low;
+ num ^= (__u32) high;
+ } else {
+#if 0
+ /*
+ * On a 386, read the high resolution timer. We assume that
+ * this gives us 2 bits of randomness.
+ *
+ * This is turned off for now because of the speed hit
+ * it entails.
+ */
+ outb_p(0x00, 0x43); /* latch the count ASAP */
+ num |= inb_p(0x40) << 16;
+ num |= inb(0x40) << 24;
+ r->entropy_count += 2;
+#endif
+
+ time = jiffies;
+ }
+#else
+ time = jiffies;
+#endif
+
+ add_entropy_word(r, (__u32) 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.
+ */
+ 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;
+
+ wake_up_interruptible(&random_wait);
+}
+
+void add_keyboard_randomness(unsigned char scancode)
+{
+ add_timer_randomness(&random_state, &keyboard_timer_state, scancode);
+}
+
+void add_mouse_randomness(__u32 mouse_data)
+{
+ add_timer_randomness(&random_state, &mouse_timer_state, mouse_data);
+}
+
+void add_interrupt_randomness(int irq)
+{
+ if (irq >= NR_IRQS || irq_timer_state[irq] == 0)
+ return;
+
+ add_timer_randomness(&random_state, irq_timer_state[irq], 0x100+irq);
+}
+
+void add_blkdev_randomness(int major)
+{
+ if (major >= MAX_BLKDEV || blkdev_timer_state[major] == 0)
+ return;
+
+ add_timer_randomness(&random_state, blkdev_timer_state[major],
+ 0x200+major);
}
/*
* 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 */
@@ -328,141 +532,10 @@
#undef F4
#undef MD5STEP
-/*
- * The function signature should be take a struct random_bucket * as
- * input, but this makes tqueue unhappy.
- */
-static void mix_bucket(void *v)
-{
- struct random_bucket *r = (struct random_bucket *) v;
- int i, num_passes;
- __u32 *p;
- __u32 iv[4];
-
- r->delay_mix = 0;
-
- /* Start IV from last block of the random pool */
- memcpy(iv, r->pool + r->length - sizeof(iv), sizeof(iv));
-
- num_passes = r->length / 16;
- for (i = 0, p = (__u32 *) r->pool; i < num_passes; i++) {
- MD5Transform(iv, rand_pool_key);
- iv[0] = (*p++ ^= iv[0]);
- iv[1] = (*p++ ^= iv[1]);
- iv[2] = (*p++ ^= iv[2]);
- iv[3] = (*p++ ^= iv[3]);
- }
- memcpy(rand_pool_key, r->pool, sizeof(rand_pool_key));
-
- /* Wipe iv from memory */
- memset(iv, 0, sizeof(iv));
-
- r->add_ptr = 0;
-}
-
-/*
- * This function adds a byte into the entropy "pool". It does not
- * update the entropy estimate. The caller must do this if appropriate.
- */
-static inline void add_entropy_byte(struct random_bucket *r,
- const __u8 ch,
- int delay)
-{
- if (!delay && r->delay_mix)
- mix_bucket(r);
- r->pool[r->add_ptr++] ^= ch;
- if (r->add_ptr >= r->length) {
- if (delay) {
- r->delay_mix = 1;
- r->add_ptr = 0;
- } else
- mix_bucket(r);
- }
-}
-/*
- * This function adds some number of bytes into the entropy pool and
- * updates the entropy count as appropriate.
- */
-void add_entropy(struct random_bucket *r, const __u8 *ptr,
- int length, int entropy_level, int delay)
-{
- while (length-- > 0)
- add_entropy_byte(r, *ptr++, delay);
-
- r->entropy_count += entropy_level;
- if (r->entropy_count > r->length*8)
- r->entropy_count = r->length * 8;
-}
-
-/*
- * 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.
- */
-static void add_timer_randomness(struct random_bucket *r,
- struct timer_rand_state *state, int delay)
-{
- int delta, delta2;
- int nbits;
-
- /*
- * Calculate number of bits of randomness we probably
- * added. We take into account the first and second order
- * delta's in order to make our estimate.
- */
- delta = jiffies - state->last_time;
- delta2 = delta - state->last_delta;
- state->last_time = jiffies;
- 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;
-
- add_entropy(r, (__u8 *) &jiffies, sizeof(jiffies),
- nbits, delay);
-
-#if defined (__i386__)
- /*
- * On a Pentium, read the cycle counter. We assume that
- * this gives us 8 bits of randomness. XXX This needs
- * investigation.
- */
- if (x86_capability & 16) {
- unsigned long low, high;
- __asm__(".byte 0x0f,0x31"
- :"=a" (low), "=d" (high));
- add_entropy_byte(r, low, 1);
- r->entropy_count += 8;
- if (r->entropy_count > r->bit_length)
- r->entropy_count = r->bit_length;
- }
+#if POOLWORDS % 16
+#error extract_entropy() assumes that POOLWORDS is a multiple of 16 words.
#endif
-}
-
-void add_keyboard_randomness(unsigned char scancode)
-{
- struct random_bucket *r = &random_state;
-
- add_timer_randomness(r, &keyboard_timer_state, 0);
- add_entropy_byte(r, scancode, 0);
- r->entropy_count += 6;
- if (r->entropy_count > r->bit_length)
- r->entropy_count = r->bit_length;
-}
-
-void add_interrupt_randomness(int irq)
-{
- struct random_bucket *r = &random_state;
-
- if (irq >= NR_IRQS)
- return;
-
- add_timer_randomness(r, &irq_timer_state[irq], 1);
-}
-
/*
* This function extracts randomness from the "entropy pool", and
* returns it in a buffer. This function computes how many remaining
@@ -472,41 +545,57 @@
static inline int extract_entropy(struct random_bucket *r, char * buf,
int nbytes, int to_user)
{
- int length, ret, passes, i;
+ int ret, i;
__u32 tmp[4];
- u8 *cp;
- add_entropy(r, (u8 *) &jiffies, sizeof(jiffies), 0, 0);
+ add_timer_randomness(r, &extract_timer_state, nbytes);
- if (r->entropy_count > r->bit_length)
- r->entropy_count = r->bit_length;
+ /* 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;
- r->entropy_count -= ret * 8;
- if (r->entropy_count < 0)
+ if (r->entropy_count / 8 >= nbytes)
+ r->entropy_count -= nbytes*8;
+ else
r->entropy_count = 0;
- passes = r->length / 64;
+
while (nbytes) {
- length = MIN(nbytes, 16);
- for (i=0; i < 16; i++) {
- if (++random_counter[i] != 0)
- break;
- }
+ /* Hash the pool to get the output */
tmp[0] = 0x67452301;
tmp[1] = 0xefcdab89;
tmp[2] = 0x98badcfe;
tmp[3] = 0x10325476;
- MD5Transform(tmp, random_counter);
- for (i = 0, cp = r->pool; i < passes; i++, cp+=64)
- MD5Transform(tmp, (__u32 *) cp);
+ 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);
if (to_user)
- memcpy_tofs(buf, tmp, length);
+ memcpy_tofs(buf, (__u8 const *)tmp, i);
else
- memcpy(buf, tmp, length);
- nbytes -= length;
- buf += length;
+ memcpy(buf, (__u8 const *)tmp, i);
+ nbytes -= i;
+ buf += i;
}
+
+ /* Wipe data from memory */
+ memset(tmp, 0, sizeof(tmp));
+
return ret;
}
@@ -520,20 +609,73 @@
extract_entropy(&random_state, (char *) buf, nbytes, 0);
}
-#ifdef linux
-int read_random(struct inode * inode,struct file * file,char * buf,int nbytes)
+int read_random(struct inode * inode, struct file * file,
+ char * buf, int nbytes)
{
- if ((nbytes * 8) > random_state.entropy_count)
+ if (nbytes > random_state.entropy_count / 8)
nbytes = random_state.entropy_count / 8;
return extract_entropy(&random_state, buf, nbytes, 1);
}
-int read_random_unlimited(struct inode * inode,struct file * file,
- char * buf,int nbytes)
+int read_random_unlimited(struct inode * inode, struct file * file,
+ char * buf, int nbytes)
{
return extract_entropy(&random_state, buf, nbytes, 1);
}
-#endif
-#endif /* CONFIG_RANDOM */
+int write_random(struct inode * inode, struct file * file,
+ const char * buffer, int count)
+{
+ int i;
+ __u32 word, *p;
+
+ for (i = count, p = (__u32 *)buffer;
+ i >= sizeof(__u32);
+ i-= sizeof(__u32), p++) {
+ memcpy_fromfs(&word, p, sizeof(__u32));
+ add_entropy_word(&random_state, word);
+ }
+ if (i) {
+ word = 0;
+ memcpy_fromfs(&word, p, i);
+ add_entropy_word(&random_state, word);
+ }
+ inode->i_mtime = CURRENT_TIME;
+ return count;
+}
+
+int random_ioctl(struct inode * inode, struct file * file,
+ unsigned int cmd, unsigned long arg)
+{
+ int *p, max_size;
+
+ switch (cmd) {
+ case RNDGETENTCNT:
+ put_user(random_state.entropy_count, (int *) arg);
+ return 0;
+ case RNDADDTOENTCNT:
+ if (!suser())
+ return -EPERM;
+ random_state.entropy_count += get_user((int *) arg);
+ if (random_state.entropy_count > POOLBITS)
+ random_state.entropy_count = POOLBITS;
+ return 0;
+ case RNDGETPOOL:
+ if (!suser())
+ return -EPERM;
+ p = (int *) arg;
+ put_user(random_state.entropy_count, p);
+ max_size = get_user(++p);
+ put_user(POOLWORDS, p);
+ if (max_size < 0)
+ return -EINVAL;
+ if (max_size > POOLWORDS)
+ max_size = POOLWORDS;
+ memcpy_tofs(++p, random_state.pool,
+ max_size*sizeof(__u32));
+ return 0;
+ default:
+ return -EINVAL;
+ }
+}
===================================================================
RCS file: drivers/char/RCS/mem.c,v
retrieving revision 1.1
diff -u -r1.1 drivers/char/mem.c
--- drivers/char/mem.c 1995/10/11 12:25:25 1.1
+++ drivers/char/mem.c 1995/10/11 19:00:00
@@ -233,7 +233,6 @@
#define mmap_kmem mmap_mem
#define zero_lseek null_lseek
#define write_zero write_null
-#define write_random write_null
static struct file_operations ram_fops = {
memory_lseek,
@@ -324,15 +323,14 @@
NULL /* no special release code */
};
-#ifdef CONFIG_RANDOM
static struct file_operations random_fops = {
memory_lseek,
read_random,
write_random,
- NULL, /* full_readdir */
- NULL, /* full_select */
- NULL, /* full_ioctl */
- NULL, /* full_mmap */
+ NULL, /* random_readdir */
+ NULL, /* random_select */
+ random_ioctl,
+ NULL, /* random_mmap */
NULL, /* no special open code */
NULL /* no special release code */
};
@@ -341,14 +339,13 @@
memory_lseek,
read_random_unlimited,
write_random,
- NULL, /* full_readdir */
- NULL, /* full_select */
- NULL, /* full_ioctl */
- NULL, /* full_mmap */
+ NULL, /* urandom_readdir */
+ NULL, /* urandom_select */
+ random_ioctl,
+ NULL, /* urandom_mmap */
NULL, /* no special open code */
NULL /* no special release code */
};
-#endif
static int memory_open(struct inode * inode, struct file * filp)
{
@@ -374,14 +371,12 @@
case 7:
filp->f_op = &full_fops;
break;
-#ifdef CONFIG_RANDOM
case 8:
filp->f_op = &random_fops;
break;
case 9:
filp->f_op = &urandom_fops;
break;
-#endif
default:
return -ENODEV;
}
@@ -407,9 +402,7 @@
{
if (register_chrdev(MEM_MAJOR,"mem",&memory_fops))
printk("unable to get major %d for memory devs\n", MEM_MAJOR);
-#ifdef CONFIG_RANDOM
rand_initialize();
-#endif
tty_init();
#ifdef CONFIG_PRINTER
lp_init();
===================================================================
RCS file: drivers/char/RCS/keyboard.c,v
retrieving revision 1.1
diff -u -r1.1 drivers/char/keyboard.c
--- drivers/char/keyboard.c 1995/10/11 12:25:25 1.1
+++ drivers/char/keyboard.c 1995/10/11 12:26:00
@@ -373,9 +373,7 @@
prev_scancode = 0;
goto end_kbd_intr;
}
-#ifdef CONFIG_RANDOM
add_keyboard_randomness(scancode);
-#endif
tty = ttytab[fg_console];
kbd = kbd_table + fg_console;
===================================================================
RCS file: drivers/char/RCS/psaux.c,v
retrieving revision 1.1
diff -u -r1.1 drivers/char/psaux.c
--- drivers/char/psaux.c 1995/10/11 17:12:06 1.1
+++ drivers/char/psaux.c 1995/10/11 17:55:31
@@ -46,6 +46,7 @@
#include <linux/timer.h>
#include <linux/malloc.h>
#include <linux/mouse.h>
+#include <linux/random.h>
#include <asm/io.h>
#include <asm/segment.h>
@@ -221,7 +222,7 @@
if ((inb(AUX_STATUS) & AUX_OBUF_FULL) != AUX_OBUF_FULL)
return;
- queue->buf[head] = inb(AUX_INPUT_PORT);
+ add_mouse_randomness(queue->buf[head] = inb(AUX_INPUT_PORT));
if (head != maxhead) {
head++;
head &= AUX_BUF_SIZE-1;
@@ -244,7 +245,7 @@
int head = queue->head;
int maxhead = (queue->tail-1) & (AUX_BUF_SIZE-1);
- queue->buf[head] = inb(qp_data);
+ add_mouse_randomness(queue->buf[head] = inb(qp_data));
if (head != maxhead) {
head++;
head &= AUX_BUF_SIZE-1;
===================================================================
RCS file: drivers/char/RCS/atixlmouse.c,v
retrieving revision 1.1
diff -u -r1.1 drivers/char/atixlmouse.c
--- drivers/char/atixlmouse.c 1995/10/11 17:45:04 1.1
+++ drivers/char/atixlmouse.c 1995/10/11 17:49:12
@@ -26,6 +26,7 @@
#include <linux/signal.h>
#include <linux/errno.h>
#include <linux/mouse.h>
+#include <linux/random.h>
#include <asm/io.h>
#include <asm/segment.h>
@@ -89,6 +90,7 @@
outb(ATIXL_MSE_READ_BUTTONS, ATIXL_MSE_CONTROL_PORT); /* Select IR0 - Button Status */
buttons = inb( ATIXL_MSE_DATA_PORT);
if (dx != 0 || dy != 0 || buttons != mouse.latch_buttons) {
+ add_mouse_randomness((buttons << 16) + (dy << 8) + dx);
mouse.latch_buttons |= buttons;
mouse.dx += dx;
mouse.dy += dy;
===================================================================
RCS file: drivers/char/RCS/busmouse.c,v
retrieving revision 1.1
diff -u -r1.1 drivers/char/busmouse.c
--- drivers/char/busmouse.c 1995/10/11 17:45:04 1.1
+++ drivers/char/busmouse.c 1995/10/11 17:49:02
@@ -46,6 +46,7 @@
#include <linux/errno.h>
#include <linux/mm.h>
#include <linux/mouse.h>
+#include <linux/random.h>
#include <asm/io.h>
#include <asm/segment.h>
@@ -78,6 +79,7 @@
dy |= (buttons & 0xf) << 4;
buttons = ((buttons >> 5) & 0x07);
if (dx != 0 || dy != 0 || buttons != mouse.buttons) {
+ add_mouse_randomness((buttons << 16) + (dy << 8) + dx);
mouse.buttons = buttons;
mouse.dx += dx;
mouse.dy -= dy;
===================================================================
RCS file: drivers/char/RCS/msbusmouse.c,v
retrieving revision 1.1
diff -u -r1.1 drivers/char/msbusmouse.c
--- drivers/char/msbusmouse.c 1995/10/11 17:45:04 1.1
+++ drivers/char/msbusmouse.c 1995/10/11 17:48:56
@@ -48,6 +48,7 @@
#include <linux/signal.h>
#include <linux/errno.h>
#include <linux/mouse.h>
+#include <linux/random.h>
#include <asm/io.h>
#include <asm/segment.h>
@@ -77,6 +78,7 @@
outb((inb(MS_MSE_DATA_PORT) & 0xdf), MS_MSE_DATA_PORT);
if (dx != 0 || dy != 0 || buttons != mouse.buttons || ((~buttons) & 0x07)) {
+ add_mouse_randomness((buttons << 16) + (dy << 8) + dx);
mouse.buttons = buttons;
mouse.dx += dx;
mouse.dy += dy;
===================================================================
RCS file: drivers/block/RCS/blk.h,v
retrieving revision 1.1
diff -u -r1.1 drivers/block/blk.h
===================================================================
RCS file: drivers/block/RCS/ide.c,v
retrieving revision 1.1
diff -u -r1.1 drivers/block/ide.c
===================================================================
RCS file: drivers/block/RCS/floppy.c,v
retrieving revision 1.1
diff -u -r1.1 drivers/block/floppy.c
===================================================================
RCS file: include/linux/RCS/random.h,v
retrieving revision 1.1
diff -u -r1.1 include/linux/random.h
--- include/linux/random.h 1995/10/11 17:51:46 1.1
+++ include/linux/random.h 1995/10/12 14:50:28
@@ -4,33 +4,44 @@
* Include file for the random number generator.
*/
-/*
- * We should always include the random number generator, since it's
- * relatively small, and it's most useful when application developers
- * can assume that all Linux systems have it. (Ideally, it would be
- * best if we could assume that all Unix systems had it, but oh
- * well....)
- *
- * Also, many kernel routines will have a use for good random numbers,
- * for example, for truely random TCP sequence numbers, which prevent
- * certain forms of TCP spoofing attacks.
- */
-#define CONFIG_RANDOM
+#ifndef _LINUX_RANDOM_H
+#define _LINUX_RANDOM_H
+
+/* ioctl()'s for the random number generator */
+
+#define RNDGETENTCNT 0x01080000
+#define RNDADDTOENTCNT 0x01080001
+#define RNDGETPOOL 0x01080002
+
+struct rand_pool_state {
+ int entropy_count;
+ int pool_size;
+ __u32 pool[0];
+};
/* Exported functions */
-#ifdef CONFIG_RANDOM
+#ifdef __KERNEL__
+
void rand_initialize(void);
+void rand_initialize_irq(int irq);
+void rand_initialize_blkdev(int irq);
void add_keyboard_randomness(unsigned char scancode);
+void add_mouse_randomness(__u32 mouse_data);
void add_interrupt_randomness(int irq);
+void add_blkdev_randomness(int major);
void get_random_bytes(void *buf, int nbytes);
int read_random(struct inode * inode, struct file * file,
char * buf, int nbytes);
int read_random_unlimited(struct inode * inode, struct file * file,
char * buf, int nbytes);
-#else
-#define add_keyboard_randomness(x)
-#define add_interrupt_randomness(x)
-#endif
+int write_random(struct inode * inode, struct file * file,
+ const char * buffer, int count);
+int random_ioctl(struct inode * inode, struct file * file,
+ unsigned int cmd, unsigned long arg);
+
+#endif /* __KERNEL___ */
+
+#endif /* _LINUX_RANDOM_H */
===================================================================
RCS file: arch/i386/kernel/RCS/irq.c,v
retrieving revision 1.1
diff -u -r1.1 arch/i386/kernel/irq.c
--- arch/i386/kernel/irq.c 1995/10/11 12:25:25 1.1
+++ arch/i386/kernel/irq.c 1995/10/11 12:26:01
@@ -214,10 +214,8 @@
#endif
kstat.interrupts[irq]++;
-#ifdef CONFIG_RANDOM
if (action->flags & SA_SAMPLE_RANDOM)
add_interrupt_randomness(irq);
-#endif
action->handler(irq, regs);
}
@@ -236,10 +234,8 @@
#endif
kstat.interrupts[irq]++;
-#ifdef CONFIG_RANDOM
if (action->flags & SA_SAMPLE_RANDOM)
add_interrupt_randomness(irq);
-#endif
action->handler(irq, NULL);
}
@@ -258,6 +254,8 @@
return -EBUSY;
if (!handler)
return -EINVAL;
+ if (irqflags & SA_SAMPLE_RANDOM)
+ rand_initialize_irq(irq);
save_flags(flags);
cli();
action->handler = handler;
===================================================================
RCS file: arch/alpha/kernel/RCS/irq.c,v
retrieving revision 1.1
diff -u -r1.1 arch/alpha/kernel/irq.c
--- arch/alpha/kernel/irq.c 1995/10/11 12:25:25 1.1
+++ arch/alpha/kernel/irq.c 1995/10/11 12:26:01
@@ -322,10 +322,8 @@
kstat.interrupts[irq]++;
action = irq_action + irq;
-#ifdef CONFIG_RANDOM
if (action->flags & SA_SAMPLE_RANDOM)
add_interrupt_randomness(irq);
-#endif
/* quick interrupts get executed with no extra overhead */
if (action->flags & SA_INTERRUPT) {
action->handler(irq, regs);