Remove unnecessary DRBG_RESEED state

The DRBG_RESEED state plays an analogue role to the |reseed_required_flag| in
Appendix B.3.4 of [NIST SP 800-90A Rev. 1]. The latter is a local variable,
the scope of which is limited to the RAND_DRBG_generate() function. Hence there
is no need for a DRBG_RESEED state outside of the generate function. This state
was removed and replaced by a local variable |reseed_required|.

Reviewed-by: Paul Dale <paul.dale@oracle.com>
Reviewed-by: Kurt Roeckx <kurt@roeckx.be>
Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Ben Kaduk <kaduk@mit.edu>
(Merged from https://github.com/openssl/openssl/pull/4328)
This commit is contained in:
Dr. Matthias St. Pierre 2017-10-09 23:51:42 +02:00 committed by Ben Kaduk
parent c16de9d832
commit e0b625f9db
2 changed files with 7 additions and 8 deletions

View file

@ -356,6 +356,8 @@ int RAND_DRBG_generate(RAND_DRBG *drbg, unsigned char *out, size_t outlen,
int prediction_resistance,
const unsigned char *adin, size_t adinlen)
{
int reseed_required = 0;
if (drbg->state != DRBG_READY) {
/* try to recover from previous errors */
rand_drbg_restart(drbg, NULL, 0, 0);
@ -381,13 +383,13 @@ int RAND_DRBG_generate(RAND_DRBG *drbg, unsigned char *out, size_t outlen,
if (drbg->fork_count != rand_fork_count) {
drbg->fork_count = rand_fork_count;
drbg->state = DRBG_RESEED;
reseed_required = 1;
}
if (drbg->reseed_counter >= drbg->reseed_interval)
drbg->state = DRBG_RESEED;
reseed_required = 1;
if (drbg->state == DRBG_RESEED || prediction_resistance) {
if (reseed_required || prediction_resistance) {
if (!RAND_DRBG_reseed(drbg, adin, adinlen)) {
RANDerr(RAND_F_RAND_DRBG_GENERATE, RAND_R_RESEED_ERROR);
return 0;
@ -402,10 +404,8 @@ int RAND_DRBG_generate(RAND_DRBG *drbg, unsigned char *out, size_t outlen,
return 0;
}
if (drbg->reseed_counter >= drbg->reseed_interval)
drbg->state = DRBG_RESEED;
else
drbg->reseed_counter++;
drbg->reseed_counter++;
return 1;
}

View file

@ -41,7 +41,6 @@
typedef enum drbg_status_e {
DRBG_UNINITIALISED,
DRBG_READY,
DRBG_RESEED,
DRBG_ERROR
} DRBG_STATUS;