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moved type and constants for random data to include file;

Browse source 
added consistency check in random; added source of randomness
internal to random using timing; only retrieve random bins that are full.
This commit is contained in:
Ben Gras 2009-04-02 15:24:44 +00:00
parent 51596bc608
commit 9647fbc94e
19 changed files with 177 additions and 80 deletions
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102
drivers/random/main.c
View file

@ -6,9 +6,7 @@
#include "../drivers.h"
#include "../libdriver/driver.h"
#include <sys/ioc_memory.h>
#include "../../kernel/const.h"
#include "../../kernel/config.h"
#include "../../kernel/type.h"
#include <minix/type.h>
#include "assert.h"
#include "random.h"
@ -32,6 +30,7 @@ FORWARD _PROTOTYPE( void r_init, (void) );
FORWARD _PROTOTYPE( int r_ioctl, (struct driver *dp, message *m_ptr, int safe) );
FORWARD _PROTOTYPE( void r_geometry, (struct partition *entry) );
FORWARD _PROTOTYPE( void r_random, (struct driver *dp, message *m_ptr) );
FORWARD _PROTOTYPE( void r_updatebin, (int source, struct k_randomness_bin *rb));
/* Entry points to this driver. */
PRIVATE struct driver r_dtab = {
@ -197,9 +196,30 @@ message *m_ptr;
*===========================================================================*/
PRIVATE void r_init()
{
/* Initialize this task. All minor devices are initialized one by one. */
static struct k_randomness krandom;
int i, s;
random_init();
r_random(NULL, NULL); /* also set periodic timer */
/* Retrieve first randomness buffer with parameters. */
if (OK != (s=sys_getrandomness(&krandom))) {
report("RANDOM", "sys_getrandomness failed", s);
exit(1);
}
/* Do sanity check on parameters. */
if(krandom.random_sources != RANDOM_SOURCES ||
krandom.random_elements != RANDOM_ELEMENTS) {
printf("random: parameters (%d, %d) don't match kernel's (%d, %d)\n",
RANDOM_SOURCES, RANDOM_ELEMENTS,
krandom.random_sources, krandom.random_elements);
exit(1);
}
/* Feed initial batch. */
for(i = 0; i < RANDOM_SOURCES; i++)
r_updatebin(i, &krandom.bin[i]);
}
/*===========================================================================*
@ -221,6 +241,45 @@ int safe; /* safe i/o? */
return(OK);
}
#define UPDATE(binnumber, bp, startitem, elems) { \
rand_t *r, *r2; \
int n = elems, item = startitem;\
int high; \
assert(binnumber >= 0 && binnumber < RANDOM_SOURCES); \
assert(item >= 0 && item < RANDOM_ELEMENTS); \
if(n > 0) { \
high = item+n-1; \
assert(high >= item); \
assert(high >= 0 && high < RANDOM_ELEMENTS); \
r = &bp->r_buf[item]; \
r2 = &bp->r_buf[high]; \
random_update(binnumber, r, n); \
} \
}
PRIVATE void r_updatebin(int source, struct k_randomness_bin *rb)
{
int r_next, r_size, r_high;
r_next= rb->r_next;
r_size= rb->r_size;
assert(r_next >= 0 && r_next < RANDOM_ELEMENTS);
assert(r_size >= 0 && r_size <= RANDOM_ELEMENTS);
r_high= r_next+r_size;
if (r_high <= RANDOM_ELEMENTS) {
UPDATE(source, rb, r_next, r_size);
} else {
assert(r_next < RANDOM_ELEMENTS);
UPDATE(source, rb, r_next, RANDOM_ELEMENTS-r_next);
UPDATE(source, rb, 0, r_high-RANDOM_ELEMENTS);
}
return;
}
/*============================================================================*
* r_random *
*============================================================================*/
@ -229,30 +288,21 @@ struct driver *dp; /* pointer to driver structure */
message *m_ptr; /* pointer to alarm message */
{
/* Fetch random information from the kernel to update /dev/random. */
int i, s, r_next, r_size, r_high;
struct randomness krandom;
int s;
static int bin = 0;
static struct k_randomness_bin krandom_bin;
u32_t hi, lo;
rand_t r;
if (OK != (s=sys_getrandomness(&krandom)))
report("RANDOM", "sys_getrandomness failed", s);
bin = (bin+1) % RANDOM_SOURCES;
for (i= 0; i<RANDOM_SOURCES; i++)
{
r_next= krandom.bin[i].r_next;
r_size= krandom.bin[i].r_size;
r_high= r_next+r_size;
if (r_high <= RANDOM_ELEMENTS)
{
random_update(i, &krandom.bin[i].r_buf[r_next], r_size);
}
else
{
assert(r_next < RANDOM_ELEMENTS);
random_update(i, &krandom.bin[i].r_buf[r_next],
RANDOM_ELEMENTS-r_next);
random_update(i, &krandom.bin[i].r_buf[0],
r_high-RANDOM_ELEMENTS);
}
}
if(sys_getrandom_bin(&krandom_bin, bin) == OK)
r_updatebin(bin, &krandom_bin);
/* Add our own timing source. */
read_tsc(&hi, &lo);
r = lo;
random_update(RND_TIMING, &r, 1);
/* Schedule new alarm for next m_random call. */
if (OK != (s=sys_setalarm(KRANDOM_PERIOD, 0)))

14
drivers/random/random.c
View file

@ -21,8 +21,8 @@ that data into a seed for a psuedo random number generator.
* re-seed.
*/
PRIVATE unsigned long deriv[RANDOM_SOURCES][N_DERIV];
PRIVATE int pool_ind[RANDOM_SOURCES];
PRIVATE unsigned long deriv[TOTAL_SOURCES][N_DERIV];
PRIVATE int pool_ind[TOTAL_SOURCES];
PRIVATE SHA256_CTX pool_ctx[NR_POOLS];
PRIVATE unsigned samples= 0;
PRIVATE int got_seeded= 0;
@ -39,10 +39,10 @@ PUBLIC void random_init()
{
int i, j;
assert(&deriv[RANDOM_SOURCES-1][N_DERIV-1] ==
&deriv[0][0] + RANDOM_SOURCES*N_DERIV -1);
assert(&deriv[TOTAL_SOURCES-1][N_DERIV-1] ==
&deriv[0][0] + TOTAL_SOURCES*N_DERIV -1);
for (i= 0; i<RANDOM_SOURCES; i++)
for (i= 0; i<TOTAL_SOURCES; i++)
{
for (j= 0; j<N_DERIV; j++)
deriv[i][j]= 0;
@ -64,7 +64,7 @@ PUBLIC int random_isseeded()
PUBLIC void random_update(source, buf, count)
int source;
unsigned short *buf;
rand_t *buf;
int count;
{
int i;
@ -72,7 +72,7 @@ int count;
#if 0
printf("random_update: got %d samples for source %d\n", count, source);
#endif
if (source < 0 || source >= RANDOM_SOURCES)
if (source < 0 || source >= TOTAL_SOURCES)
panic("memory", "random_update: bad source", source);
for (i= 0; i<count; i++)
add_sample(source, buf[i]);

8
drivers/random/random.h
View file

@ -4,9 +4,13 @@ random.h
Public interface to the random number generator
*/
/* Internal random sources */
#define RND_TIMING 0
#define RANDOM_SOURCES_INTERNAL 1
#define TOTAL_SOURCES (RANDOM_SOURCES+RANDOM_SOURCES_INTERNAL)
_PROTOTYPE( void random_init, (void) );
_PROTOTYPE( int random_isseeded, (void) );
_PROTOTYPE( void random_update, (int source, unsigned short *buf,
int count) );
_PROTOTYPE( void random_update, (int source, rand_t *buf, int count) );
_PROTOTYPE( void random_getbytes, (void *buf, size_t size) );
_PROTOTYPE( void random_putbytes, (void *buf, size_t size) );

1
include/minix/com.h
View file

@ -461,6 +461,7 @@
# define GET_PRIVID 17 /* get ID of privilege structure */
# define GET_HZ 18 /* get HZ value */
# define GET_WHOAMI 19 /* get own name and endpoint */
# define GET_RANDOMNESS_BIN 20 /* get one randomness bin */
#define I_ENDPT m7_i4 /* calling process */
#define I_VAL_PTR m7_p1 /* virtual address at caller */
#define I_VAL_LEN m7_i1 /* max length of value */

1
include/minix/syslib.h
View file

@ -156,6 +156,7 @@ _PROTOTYPE(int sys_segctl, (int *index, u16_t *seg, vir_bytes *off,
#define sys_getprivtab(dst) sys_getinfo(GET_PRIVTAB, dst, 0,0,0)
#define sys_getproc(dst,nr) sys_getinfo(GET_PROC, dst, 0,0, nr)
#define sys_getrandomness(dst) sys_getinfo(GET_RANDOMNESS, dst, 0,0,0)
#define sys_getrandom_bin(d,b) sys_getinfo(GET_RANDOMNESS_BIN, d, 0,0,b)
#define sys_getimage(dst) sys_getinfo(GET_IMAGE, dst, 0,0,0)
#define sys_getirqhooks(dst) sys_getinfo(GET_IRQHOOKS, dst, 0,0,0)
#define sys_getirqactids(dst) sys_getinfo(GET_IRQACTIDS, dst, 0,0,0)

2
include/minix/sysutil.h
View file

@ -58,6 +58,8 @@ _PROTOTYPE( int micro_delay, (u32_t micros));
_PROTOTYPE( u32_t micros_to_ticks, (u32_t micros));
_PROTOTYPE( int asynsend, (endpoint_t ep, message *msg));
_PROTOTYPE( void ser_putc, (char c));
_PROTOTYPE( void get_randomness, (struct k_randomness *, int));
#define ASSERT(c) if(!(c)) { panic(__FILE__, "assert " #c " failed at line", __LINE__); }

16
include/minix/type.h
View file

@ -178,6 +178,22 @@ struct kmessages {
char km_buf[_KMESS_BUF_SIZE]; /* buffer for messages */
};
#include <ibm/interrupt.h>
/* randomness struct: random sources after interrupts: */
#define RANDOM_SOURCES NR_IRQ_VECTORS
#define RANDOM_ELEMENTS 64
typedef unsigned short rand_t;
struct k_randomness {
int random_elements, random_sources;
struct k_randomness_bin {
int r_next; /* next index to write */
int r_size; /* number of random elements */
rand_t r_buf[RANDOM_ELEMENTS]; /* buffer for random info */
} bin[RANDOM_SOURCES];
};
#endif /* _TYPE_H */

2
kernel/arch/i386/do_int86.c
View file

@ -36,7 +36,7 @@ register message *m_ptr; /* pointer to request message */
* not very random.
*/
lock;
get_randomness(CLOCK_IRQ);
get_randomness(&krandom, CLOCK_IRQ);
unlock;
return(OK);

5
kernel/config.h
View file

@ -49,11 +49,6 @@
*/
#define P_NAME_LEN 8
/* Buffer to gather randomness. This is used to generate a random stream by
* the MEMORY driver when reading from /dev/random.
*/
#define RANDOM_ELEMENTS 32
/* This section contains defines for valuable system resources that are used
* by device drivers. The number of elements of the vectors is determined by
* the maximum needed by any given driver. The number of interrupt hooks may

3
kernel/const.h
View file

@ -25,9 +25,6 @@
#define _SRC_ 0
#define _DST_ 1
/* Number of random sources */
#define RANDOM_SOURCES 16
#define get_sys_bit(map,bit) \
( MAP_CHUNK(map.chunk,bit) & (1 << CHUNK_OFFSET(bit) )
#define get_sys_bits(map,bit) \

2
kernel/glo.h
View file

@ -25,7 +25,7 @@ EXTERN char shutdown_started; /* TRUE after shutdowns / reboots */
EXTERN struct kinfo kinfo; /* kernel information for users */
EXTERN struct machine machine; /* machine information for users */
EXTERN struct kmessages kmess; /* diagnostic messages in kernel */
EXTERN struct randomness krandom; /* gather kernel random information */
EXTERN struct k_randomness krandom; /* gather kernel random information */
EXTERN struct loadinfo kloadinfo; /* status of load average */
/* Process scheduling information and the kernel reentry count. */

2
kernel/main.c
View file

@ -175,6 +175,8 @@ PUBLIC void main()
cprof_procs_no = 0; /* init nr of hash table slots used */
vm_running = 0;
krandom.random_sources = RANDOM_SOURCES;
krandom.random_elements = RANDOM_ELEMENTS;
/* MINIX is now ready. All boot image processes are on the ready queue.
* Return to the assembly code to start running the current process.

1
kernel/proto.h
View file

@ -58,7 +58,6 @@ _PROTOTYPE( int get_priv, (register struct proc *rc, int proc_type) );
_PROTOTYPE( void send_sig, (int proc_nr, int sig_nr) );
_PROTOTYPE( void cause_sig, (int proc_nr, int sig_nr) );
_PROTOTYPE( void sys_task, (void) );
_PROTOTYPE( void get_randomness, (int source) );
#define numap_local(proc_nr, vir_addr, bytes) \
umap_local(proc_addr(proc_nr), D, (vir_addr), (bytes))
_PROTOTYPE( phys_bytes umap_grant, (struct proc *, cp_grant_id_t,

22
kernel/system.c
View file

@ -290,28 +290,6 @@ int proc_type; /* system or user process flag */
return(OK);
}
/*===========================================================================*
* get_randomness *
*===========================================================================*/
PUBLIC void get_randomness(source)
int source;
{
/* Use architecture-dependent high-resolution clock for
* raw entropy gathering.
*/
int r_next;
unsigned long tsc_high, tsc_low;
source %= RANDOM_SOURCES;
r_next= krandom.bin[source].r_next;
read_tsc(&tsc_high, &tsc_low);
krandom.bin[source].r_buf[r_next] = tsc_low;
if (krandom.bin[source].r_size < RANDOM_ELEMENTS) {
krandom.bin[source].r_size ++;
}
krandom.bin[source].r_next = (r_next + 1 ) % RANDOM_ELEMENTS;
}
/*===========================================================================*
* send_sig *
*===========================================================================*/

30
kernel/system/do_getinfo.c
View file

@ -31,6 +31,7 @@ register message *m_ptr; /* pointer to request message */
int proc_nr, nr_e, nr;
struct proc *caller;
phys_bytes ph;
int wipe_rnd_bin = -1;
caller = proc_addr(who_p);
@ -112,7 +113,7 @@ register message *m_ptr; /* pointer to request message */
break;
}
case GET_RANDOMNESS: {
static struct randomness copy; /* copy to keep counters */
static struct k_randomness copy; /* copy to keep counters */
int i;
copy = krandom;
@ -120,10 +121,28 @@ register message *m_ptr; /* pointer to request message */
krandom.bin[i].r_size = 0; /* invalidate random data */
krandom.bin[i].r_next = 0;
}
length = sizeof(struct randomness);
length = sizeof(copy);
src_vir = (vir_bytes) &copy;
break;
}
case GET_RANDOMNESS_BIN: {
int i, bin = m_ptr->I_VAL_LEN2_E;
if(bin < 0 || bin >= RANDOM_SOURCES) {
kprintf("SYSTEM: GET_RANDOMNESS_BIN: %d out of range\n", bin);
return EINVAL;
}
if(krandom.bin[bin].r_size < RANDOM_ELEMENTS)
return ENOENT;
length = sizeof(krandom.bin[bin]);
src_vir = (vir_bytes) &krandom.bin[bin];
wipe_rnd_bin = bin;
break;
}
case GET_KMESSAGES: {
length = sizeof(struct kmessages);
src_vir = (vir_bytes) &kmess;
@ -158,7 +177,12 @@ register message *m_ptr; /* pointer to request message */
if((ph=umap_local(caller, D, (vir_bytes) m_ptr->I_VAL_PTR,length)) == 0)
return EFAULT;
CHECKRANGE_OR_SUSPEND(caller, ph, length, 1);
data_copy(SYSTEM, src_vir, who_e, (vir_bytes) m_ptr->I_VAL_PTR, length);
if(data_copy(SYSTEM, src_vir, who_e, (vir_bytes) m_ptr->I_VAL_PTR, length) == OK) {
if(wipe_rnd_bin >= 0 && wipe_rnd_bin < RANDOM_SOURCES) {
krandom.bin[wipe_rnd_bin].r_size = 0;
krandom.bin[wipe_rnd_bin].r_next = 0;
}
}
return(OK);
}

2
kernel/system/do_irqctl.c
View file

@ -142,7 +142,7 @@ irq_hook_t *hook;
/* As a side-effect, the interrupt handler gathers random information by
* timestamping the interrupt events. This is used for /dev/random.
*/
get_randomness(hook->irq);
get_randomness(&krandom, hook->irq);
/* Check if the handler is still alive.
* If it's dead, this should never happen, as processes that die

9
kernel/type.h
View file

@ -2,6 +2,7 @@
#define TYPE_H
#include <minix/com.h>
#include <ibm/interrupt.h>
typedef _PROTOTYPE( void task_t, (void) );
@ -27,14 +28,6 @@ struct boot_image {
endpoint_t endpoint; /* endpoint number when started */
};
struct randomness {
struct {
int r_next; /* next index to write */
int r_size; /* number of random elements */
unsigned short r_buf[RANDOM_ELEMENTS]; /* buffer for random info */
} bin[RANDOM_SOURCES];
};
typedef unsigned long irq_policy_t;
typedef unsigned long irq_id_t;

1
lib/sysutil/Makefile.in
View file

@ -10,6 +10,7 @@ libsys_FILES=" \
kprintf.c \
kputc.c \
tickdelay.c \
get_randomness.c \
getuptime.c \
getuptime2.c \
env_get_prm.c \

34
lib/sysutil/get_randomness.c Normal file
View file

@ -0,0 +1,34 @@
#include <lib.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <minix/profile.h>
#include <minix/syslib.h>
#include <minix/type.h>
#include <minix/sysutil.h>
/*===========================================================================*
* get_randomness *
*===========================================================================*/
PUBLIC void get_randomness(rand, source)
struct k_randomness *rand;
int source;
{
/* Use architecture-dependent high-resolution clock for
* raw entropy gathering.
*/
int r_next;
unsigned long tsc_high, tsc_low;
source %= RANDOM_SOURCES;
r_next= rand->bin[source].r_next;
read_tsc(&tsc_high, &tsc_low);
rand->bin[source].r_buf[r_next] = tsc_low;
if (rand->bin[source].r_size < RANDOM_ELEMENTS) {
rand->bin[source].r_size ++;
}
rand->bin[source].r_next = (r_next + 1 ) % RANDOM_ELEMENTS;
}