ClearML/dropbear
1
0
Fork 0
mirror of https://github.com/clearml/dropbear synced 2025-06-26 18:17:32 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

Use atomic key generation in all cases

Browse Source
This commit is contained in:
Matt Johnston
2016-11-19 00:31:21 +08:00
parent 9025cd9b72
commit 597f12c44a
6 changed files with 57 additions and 52 deletions
Download Patch File Download Diff File Expand all files Collapse all files

47
svr-kex.c
View File

@@ -87,29 +87,9 @@ void recv_msg_kexdh_init() {
#ifdef DROPBEAR_DELAY_HOSTKEY
static void fsync_parent_dir(const char* fn) {
#ifdef HAVE_LIBGEN_H
char *fn_dir = m_strdup(fn);
char *dir = dirname(fn_dir);
int dirfd = open(dir, O_RDONLY);
if (dirfd != -1) {
if (fsync(dirfd) != 0) {
TRACE(("fsync of directory %s failed: %s", dir, strerror(errno)))
}
m_close(dirfd);
} else {
TRACE(("error opening directory %s for fsync: %s", dir, strerror(errno)))
}
free(fn_dir);
#endif
}
static void svr_ensure_hostkey() {
const char* fn = NULL;
char *fn_temp = NULL;
enum signkey_type type = ses.newkeys->algo_hostkey;
void **hostkey = signkey_key_ptr(svr_opts.hostkey, type);
int ret = DROPBEAR_FAILURE;
@@ -145,28 +125,10 @@ static void svr_ensure_hostkey() {
return;
}
fn_temp = m_malloc(strlen(fn) + 20);
snprintf(fn_temp, strlen(fn)+20, "%s.tmp%d", fn, getpid());
if (signkey_generate(type, 0, fn_temp) == DROPBEAR_FAILURE) {
if (signkey_generate(type, 0, fn, 1) == DROPBEAR_FAILURE) {
goto out;
}
if (link(fn_temp, fn) < 0) {
/* It's OK to get EEXIST - we probably just lost a race
with another connection to generate the key */
if (errno != EEXIST) {
dropbear_log(LOG_ERR, "Failed moving key file to %s: %s", fn,
strerror(errno));
/* XXX fallback to non-atomic copy for some filesystems? */
goto out;
}
}
/* ensure directory update is flushed to disk, otherwise we can end up
with zero-byte hostkey files if the power goes off */
fsync_parent_dir(fn);
ret = readhostkey(fn, svr_opts.hostkey, &type);
if (ret == DROPBEAR_SUCCESS) {
@@ -184,11 +146,6 @@ static void svr_ensure_hostkey() {
}
out:
if (fn_temp) {
unlink(fn_temp);
m_free(fn_temp);
}
if (ret == DROPBEAR_FAILURE)
{
dropbear_exit("Couldn't read or generate hostkey %s", fn);