faraphel/chrony
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

sourcestats: align sample time used for source report

Browse source 
This reduces leak of sample times (and receive timestamps which are
related to sample times), which could be useful in off-path attacks on
unauthenticated symmetric interleaved mode.
This commit is contained in:
Miroslav Lichvar 2017-01-12 12:21:50 +01:00
parent 48b16ae66c
commit ac0b28cce6
1 changed files with 5 additions and 3 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

8
sourcestats.c
View file

@ -928,7 +928,7 @@ void
SST_DoSourceReport(SST_Stats inst, RPT_SourceReport *report, struct timespec *now)
{
int i, j;
struct timespec ago;
struct timespec last_sample_time;
if (inst->n_samples > 0) {
i = get_runsbuf_index(inst, inst->n_samples - 1);
@ -938,8 +938,10 @@ SST_DoSourceReport(SST_Stats inst, RPT_SourceReport *report, struct timespec *no
report->latest_meas_err = 0.5*inst->root_delays[j] + inst->root_dispersions[j];
report->stratum = inst->strata[j];
UTI_DiffTimespecs(&ago, now, &inst->sample_times[i]);
report->latest_meas_ago = ago.tv_sec;
/* Align the sample time to reduce the leak of the receive timestamp */
last_sample_time = inst->sample_times[i];
last_sample_time.tv_nsec = 0;
report->latest_meas_ago = UTI_DiffTimespecsToDouble(now, &last_sample_time);
} else {
report->latest_meas_ago = (uint32_t)-1;
report->orig_latest_meas = 0;