From e0b625f9db00509af9004b7907d44b78f332754a Mon Sep 17 00:00:00 2001 From: "Dr. Matthias St. Pierre" Date: Mon, 9 Oct 2017 23:51:42 +0200 Subject: [PATCH] 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 Reviewed-by: Kurt Roeckx Reviewed-by: Rich Salz Reviewed-by: Ben Kaduk (Merged from https://github.com/openssl/openssl/pull/4328) --- crypto/rand/drbg_lib.c | 14 +++++++------- crypto/rand/rand_lcl.h | 1 - 2 files changed, 7 insertions(+), 8 deletions(-) diff --git a/crypto/rand/drbg_lib.c b/crypto/rand/drbg_lib.c index eef5e11cc5..0042a931b0 100644 --- a/crypto/rand/drbg_lib.c +++ b/crypto/rand/drbg_lib.c @@ -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; } diff --git a/crypto/rand/rand_lcl.h b/crypto/rand/rand_lcl.h index 10a6f00a2d..5e319d8c99 100644 --- a/crypto/rand/rand_lcl.h +++ b/crypto/rand/rand_lcl.h @@ -41,7 +41,6 @@ typedef enum drbg_status_e { DRBG_UNINITIALISED, DRBG_READY, - DRBG_RESEED, DRBG_ERROR } DRBG_STATUS; -- 2.25.1