From: Alexander Sosedkin Date: Tue, 9 Aug 2022 14:05:53 +0000 (+0200) Subject: auth/rsa: side-step potential side-channel X-Git-Tag: 3.8.0~1^2~2 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=80a6ce8ddb02477cd724cd5b2944791aaddb702a;p=thirdparty%2Fgnutls.git auth/rsa: side-step potential side-channel Remove branching that depends on secret data. Signed-off-by: Alexander Sosedkin Signed-off-by: Hubert Kario Tested-by: Hubert Kario --- diff --git a/lib/auth/rsa.c b/lib/auth/rsa.c index 62c86e470a..562518d93e 100644 --- a/lib/auth/rsa.c +++ b/lib/auth/rsa.c @@ -154,7 +154,6 @@ _gnutls_get_public_rsa_params(gnutls_session_t session, static int proc_rsa_client_kx(gnutls_session_t session, uint8_t * data, size_t _data_size) { - const char attack_error[] = "auth_rsa: Possible PKCS #1 attack\n"; gnutls_datum_t ciphertext; int ret, dsize; ssize_t data_size = _data_size; @@ -234,15 +233,6 @@ proc_rsa_client_kx(gnutls_session_t session, uint8_t * data, size_t _data_size) ok &= CONSTCHECK_NOT_EQUAL(check_ver_min, 0) & CONSTCHECK_EQUAL(session->key.key.data[1], ver_min); - if (ok) { - /* call logging function unconditionally so all branches are - * indistinguishable for timing and cache access when debug - * logging is disabled */ - _gnutls_no_log("%s", attack_error); - } else { - _gnutls_debug_log("%s", attack_error); - } - /* This is here to avoid the version check attack * discussed above. */