From 82925f9dd0492f2e5f1d80ff46fd59f0704c8fe6 Mon Sep 17 00:00:00 2001 From: Pauli Date: Tue, 23 Jul 2019 16:54:52 +1000 Subject: [PATCH] Avoid double clearing some BIGNUMs Reviewed-by: Richard Levitte (Merged from https://github.com/openssl/openssl/pull/9438) --- crypto/bn/bn_lib.c | 20 +++++++++----------- 1 file changed, 9 insertions(+), 11 deletions(-) diff --git a/crypto/bn/bn_lib.c b/crypto/bn/bn_lib.c index 17293ede34..5719a00ebf 100644 --- a/crypto/bn/bn_lib.c +++ b/crypto/bn/bn_lib.c @@ -142,10 +142,12 @@ int BN_num_bits(const BIGNUM *a) return ((i * BN_BITS2) + BN_num_bits_word(a->d[i])); } -static void bn_free_d(BIGNUM *a) +static void bn_free_d(BIGNUM *a, int clear) { if (BN_get_flags(a, BN_FLG_SECURE)) - OPENSSL_secure_free(a->d); + OPENSSL_secure_clear_free(a->d, a->dmax * sizeof(a->d[0])); + else if (clear != 0) + OPENSSL_clear_free(a->d, a->dmax * sizeof(a->d[0])); else OPENSSL_free(a->d); } @@ -155,10 +157,8 @@ void BN_clear_free(BIGNUM *a) { if (a == NULL) return; - if (a->d != NULL && !BN_get_flags(a, BN_FLG_STATIC_DATA)) { - OPENSSL_cleanse(a->d, a->dmax * sizeof(a->d[0])); - bn_free_d(a); - } + if (a->d != NULL && !BN_get_flags(a, BN_FLG_STATIC_DATA)) + bn_free_d(a, 1); if (BN_get_flags(a, BN_FLG_MALLOCED)) { OPENSSL_cleanse(a, sizeof(*a)); OPENSSL_free(a); @@ -170,7 +170,7 @@ void BN_free(BIGNUM *a) if (a == NULL) return; if (!BN_get_flags(a, BN_FLG_STATIC_DATA)) - bn_free_d(a); + bn_free_d(a, 0); if (a->flags & BN_FLG_MALLOCED) OPENSSL_free(a); } @@ -248,10 +248,8 @@ BIGNUM *bn_expand2(BIGNUM *b, int words) BN_ULONG *a = bn_expand_internal(b, words); if (!a) return NULL; - if (b->d) { - OPENSSL_cleanse(b->d, b->dmax * sizeof(b->d[0])); - bn_free_d(b); - } + if (b->d != NULL) + bn_free_d(b, 1); b->d = a; b->dmax = words; } -- 2.25.1