diff options
| -rw-r--r-- | changes/warn-when-time-goes-backwards | 5 | ||||
| -rw-r--r-- | src/or/statefile.c | 12 |
2 files changed, 17 insertions, 0 deletions
diff --git a/changes/warn-when-time-goes-backwards b/changes/warn-when-time-goes-backwards new file mode 100644 index 0000000000..d7e584d9ff --- /dev/null +++ b/changes/warn-when-time-goes-backwards @@ -0,0 +1,5 @@ + o Minor features (security, clock): + - Warn when the system clock is set back in time (when the + state file was last written in the future). Tor doesn't know + that consensuses have expired if the clock is in the past. + Patch by "teor". Implements ticket #17188. diff --git a/src/or/statefile.c b/src/or/statefile.c index dd1894beb7..a904c411f4 100644 --- a/src/or/statefile.c +++ b/src/or/statefile.c @@ -372,6 +372,18 @@ or_state_load(void) new_state = or_state_new(); } else if (contents) { log_info(LD_GENERAL, "Loaded state from \"%s\"", fname); + /* Warn the user if their clock has been set backwards, + * they could be tricked into using old consensuses */ + if (new_state->LastWritten > time(NULL)) { + char last_written_str[ISO_TIME_LEN+1]; + char now_str[ISO_TIME_LEN+1]; + format_iso_time(last_written_str, new_state->LastWritten), + format_iso_time(now_str, time(NULL)); + log_warn(LD_GENERAL, "Your system clock has been set back in time. " + "Tor needs an accurate clock to know when the consensus " + "expires. Clock time is %s, state file time is %s.", + now_str, last_written_str); + } } else { log_info(LD_GENERAL, "Initialized state"); } |