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Small update to random number generator

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This commit is contained in:
Philip Homburg
2005-07-19 12:16:55 +00:00
parent 488b2afc12
commit f8c380c195
4 changed files with 65 additions and 41 deletions
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drivers/memory/memory.c
+2 -6
View File
@@ -27,7 +27,7 @@
#include "random.h"
#define NR_DEVS 7 /* number of minor devices */
#define KRANDOM_PERIOD 10 /* ticks between krandom calls */
#define KRANDOM_PERIOD 1 /* ticks between krandom calls */
PRIVATE struct device m_geom[NR_DEVS]; /* base and size of each device */
PRIVATE int m_seg[NR_DEVS]; /* segment index of each device */
@@ -183,12 +183,8 @@ unsigned nr_req; /* length of request vector */
/* Random number generator. Character instead of block device. */
case RANDOM_DEV:
if (opcode == DEV_GATHER)
{
s= random_reseed();
if (s < 0)
if (opcode == DEV_GATHER && !random_isseeded())
return(EAGAIN);
}
left = count;
while (left > 0) {
chunk = (left > RANDOM_BUF_SIZE) ? RANDOM_BUF_SIZE : left;
drivers/memory/random.c
+42 -34
View File
@@ -33,6 +33,7 @@ PRIVATE u32_t reseed_count;
FORWARD _PROTOTYPE( void add_sample, (int source, unsigned long sample) );
FORWARD _PROTOTYPE( void data_block, (rd_keyinstance *keyp,
void *data) );
FORWARD _PROTOTYPE( void reseed, (void) );
PUBLIC void random_init()
{
@@ -54,42 +55,11 @@ PUBLIC void random_init()
reseed_count= 0;
}
PUBLIC int random_reseed()
PUBLIC int random_isseeded()
{
int i;
SHA256_CTX ctx;
u8_t digest[SHA256_DIGEST_LENGTH];
if (samples >= MIN_SAMPLES)
{
reseed_count++;
printf("random_reseed: round %d, samples = %d\n",
reseed_count, samples);
SHA256_Init(&ctx);
if (got_seeded)
SHA256_Update(&ctx, random_key, sizeof(random_key));
SHA256_Final(digest, &pool_ctx[0]);
SHA256_Update(&ctx, digest, sizeof(digest));
SHA256_Init(&pool_ctx[0]);
for (i= 1; i<NR_POOLS; i++)
{
if ((reseed_count & (1UL << (i-1))) != 0)
break;
printf("random_reseed: adding pool %d\n", i);
SHA256_Final(digest, &pool_ctx[i]);
SHA256_Update(&ctx, digest, sizeof(digest));
SHA256_Init(&pool_ctx[i]);
}
SHA256_Final(digest, &ctx);
assert(sizeof(random_key) == sizeof(digest));
memcpy(random_key, &digest, sizeof(random_key));
samples= 0;
got_seeded= 1;
}
if (got_seeded)
return 0;
return -1;
return 1;
return 0;
}
PUBLIC void random_update(source, buf, count)
@@ -106,6 +76,7 @@ int count;
panic("memory", "random_update: bad source", source);
for (i= 0; i<count; i++)
add_sample(source, buf[i]);
reseed();
}
PUBLIC void random_getbytes(buf, size)
@@ -153,6 +124,8 @@ size_t size;
* with the number of bits.
*/
samples += size*8;
reseed();
}
PRIVATE void add_sample(source, sample)
@@ -230,3 +203,38 @@ void *data;
if (count_lo == 0)
count_hi++;
}
PRIVATE void reseed()
{
int i;
SHA256_CTX ctx;
u8_t digest[SHA256_DIGEST_LENGTH];
if (samples < MIN_SAMPLES)
return;
reseed_count++;
printf("reseed: round %d, samples = %d\n", reseed_count, samples);
SHA256_Init(&ctx);
if (got_seeded)
SHA256_Update(&ctx, random_key, sizeof(random_key));
SHA256_Final(digest, &pool_ctx[0]);
SHA256_Update(&ctx, digest, sizeof(digest));
SHA256_Init(&pool_ctx[0]);
for (i= 1; i<NR_POOLS; i++)
{
if ((reseed_count & (1UL << (i-1))) != 0)
break;
printf("random_reseed: adding pool %d\n", i);
SHA256_Final(digest, &pool_ctx[i]);
SHA256_Update(&ctx, digest, sizeof(digest));
SHA256_Init(&pool_ctx[i]);
}
SHA256_Final(digest, &ctx);
assert(sizeof(random_key) == sizeof(digest));
memcpy(random_key, &digest, sizeof(random_key));
samples= 0;
got_seeded= 1;
}
drivers/memory/random.h
+1 -1
View File
@@ -5,7 +5,7 @@ Public interface to the random number generator
*/
_PROTOTYPE( void random_init, (void) );
_PROTOTYPE( int random_reseed, (void) );
_PROTOTYPE( int random_isseeded, (void) );
_PROTOTYPE( void random_update, (int source, unsigned long *buf,
int count) );
_PROTOTYPE( void random_getbytes, (void *buf, size_t size) );