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| author | Matthias Schiffer <mschiffer@universe-factory.net> | 2013-08-20 06:52:03 +0200 |
|---|---|---|
| committer | Matthias Schiffer <mschiffer@universe-factory.net> | 2013-08-20 06:52:03 +0200 |
| commit | f6640a80f4be19e988fd7426c3f897f4d3f614e4 (patch) | |
| tree | 3b6764fc547ee9ea1559ed1fb2c9b4fd4eb0726a | |
| parent | d9dc87d8409ddf8361b7fcb311ae97088ed1d984 (diff) | |
| download | fastd-f6640a80f4be19e988fd7426c3f897f4d3f614e4.tar fastd-f6640a80f4be19e988fd7426c3f897f4d3f614e4.zip | |
Prevent zero-before-free operations from being optimized out
| -rw-r--r-- | src/fastd.h | 5 | ||||
| -rw-r--r-- | src/method_aes128_gcm.c | 2 | ||||
| -rw-r--r-- | src/method_xsalsa20_poly1305.c | 4 | ||||
| -rw-r--r-- | src/protocol_ec25519_fhmqvc.c | 2 |
4 files changed, 9 insertions, 4 deletions
diff --git a/src/fastd.h b/src/fastd.h index 723b1e7..efd785a 100644 --- a/src/fastd.h +++ b/src/fastd.h @@ -497,4 +497,9 @@ static inline size_t min_size_t(size_t a, size_t b) { return (a < b) ? a : b; } +static inline void secure_memzero(void *s, size_t n) { + memset(s, 0, n); + asm volatile("" : : "m"(s)); +} + #endif /* _FASTD_FASTD_H_ */ diff --git a/src/method_aes128_gcm.c b/src/method_aes128_gcm.c index f392e2e..3670225 100644 --- a/src/method_aes128_gcm.c +++ b/src/method_aes128_gcm.c @@ -150,7 +150,7 @@ static void method_session_free(fastd_context_t *ctx, fastd_method_session_state ctx->conf->crypto_aes128ctr->free_state(ctx, session->cstate_aes128ctr); ctx->conf->crypto_ghash->free_state(ctx, session->cstate_ghash); - memset(session, 0, sizeof(fastd_method_session_state_t)); + secure_memzero(session, sizeof(fastd_method_session_state_t)); free(session); } } diff --git a/src/method_xsalsa20_poly1305.c b/src/method_xsalsa20_poly1305.c index 1e26247..9bcf5ed 100644 --- a/src/method_xsalsa20_poly1305.c +++ b/src/method_xsalsa20_poly1305.c @@ -131,7 +131,7 @@ static bool method_session_want_refresh(fastd_context_t *ctx, fastd_method_sessi static void method_session_free(fastd_context_t *ctx UNUSED, fastd_method_session_state_t *session) { if(session) { - memset(session, 0, sizeof(fastd_method_session_state_t)); + secure_memzero(session, sizeof(fastd_method_session_state_t)); free(session); } } @@ -180,7 +180,7 @@ static bool method_decrypt(fastd_context_t *ctx, fastd_peer_t *peer, fastd_metho if (age > ctx->conf->reorder_count) return false; } - + fastd_buffer_pull_head(ctx, &in, crypto_secretbox_xsalsa20poly1305_BOXZEROBYTES-NONCEBYTES); memset(in.data, 0, crypto_secretbox_xsalsa20poly1305_BOXZEROBYTES); diff --git a/src/protocol_ec25519_fhmqvc.c b/src/protocol_ec25519_fhmqvc.c index b3bd8a5..b687a91 100644 --- a/src/protocol_ec25519_fhmqvc.c +++ b/src/protocol_ec25519_fhmqvc.c @@ -837,7 +837,7 @@ static void protocol_init_peer_state(fastd_context_t *ctx, fastd_peer_t *peer) { static void reset_session(fastd_context_t *ctx, protocol_session_t *session) { if (session->method) session->method->session_free(ctx, session->method_state); - memset(session, 0, sizeof(protocol_session_t)); + secure_memzero(session, sizeof(protocol_session_t)); } static void protocol_reset_peer_state(fastd_context_t *ctx, fastd_peer_t *peer) { |