From bcba17939e1b1a568cd4a764534cde74d37078cc Mon Sep 17 00:00:00 2001 From: Christian Göttsche Date: Mon, 30 Jan 2023 17:56:58 +0100 Subject: modules: make use of secure memory erasure Use empty initialization of structs to minimize the memset() usage, to reduce the amount of calls which are not sensitive. Non trivial changes: - pam_env: * erase environment variables where possible - pam_exec: * erase responce on error * erase auth token - pam_pwhistory: * erase buffers containing old passwords - pam_selinux: skip overwriting data structure consisting of only pointers to insensitive data, which also gets free'd afterwards (so it currently does not protect against double-free or use-after-free on the member pointers) - pam_unix: erase cipher data in more places - pam_userdb: erase password hashes --- modules/pam_timestamp/hmac_openssl_wrapper.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'modules/pam_timestamp/hmac_openssl_wrapper.c') diff --git a/modules/pam_timestamp/hmac_openssl_wrapper.c b/modules/pam_timestamp/hmac_openssl_wrapper.c index 926c2fb9..df772d60 100644 --- a/modules/pam_timestamp/hmac_openssl_wrapper.c +++ b/modules/pam_timestamp/hmac_openssl_wrapper.c @@ -144,7 +144,7 @@ read_file(pam_handle_t *pamh, int fd, char **text, size_t *text_length) if (bytes_read < (size_t)st.st_size) { pam_syslog(pamh, LOG_ERR, "Short read on key file"); - memset(tmp, 0, st.st_size); + pam_overwrite_n(tmp, st.st_size); free(tmp); return PAM_AUTH_ERR; } @@ -167,14 +167,14 @@ write_file(pam_handle_t *pamh, const char *file_name, char *text, S_IRUSR | S_IWUSR); if (fd == -1) { pam_syslog(pamh, LOG_ERR, "Unable to open [%s]: %m", file_name); - memset(text, 0, text_length); + pam_overwrite_n(text, text_length); free(text); return PAM_AUTH_ERR; } if (fchown(fd, owner, group) == -1) { pam_syslog(pamh, LOG_ERR, "Unable to change ownership [%s]: %m", file_name); - memset(text, 0, text_length); + pam_overwrite_n(text, text_length); free(text); close(fd); return PAM_AUTH_ERR; @@ -294,7 +294,7 @@ done: free(hmac_message); } if (key != NULL) { - memset(key, 0, key_length); + pam_overwrite_n(key, key_length); free(key); } if (ctx != NULL) { -- cgit v1.2.3