vincenzopalazzo
/
arti
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Give an error if the cache violates If-Modified-Since. 

This should be sufficient to detect several kinds of nefariousness
that we'd previously overlooked.
This commit is contained in:
Nick Mathewson 2022-05-13 16:10:28 -04:00
parent 37f6730077
commit e37e37a31c
1 changed files with 24 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

31
crates/tor-dirmgr/src/state.rs
View File

@ -296,7 +296,7 @@ impl<R: Runtime> DirState for GetConsensusState<R> {
};
let source = DocSource::LocalCache;
match self.add_consensus_text(source, text.as_str().map_err(Error::BadUtf8InCache)?) {
match self.add_consensus_text(source, text.as_str().map_err(Error::BadUtf8InCache)?, None) {
Ok(_) => Ok((true, None)),
Err(e) => Ok((false, Some(e))),
}
@ -304,11 +304,15 @@ impl<R: Runtime> DirState for GetConsensusState<R> {
fn add_from_download(
&mut self,
text: &str,
_request: &ClientRequest,
request: &ClientRequest,
source: DocSource,
storage: Option<&Mutex<DynStore>>,
) -> Result<(bool, Option<Error>)> {
match self.add_consensus_text(source, text) {
let requested_newer_than = match request {
ClientRequest::Consensus(r) => r.last_consensus_date(),
_ => None,
};
match self.add_consensus_text(source, text, requested_newer_than) {
Ok(meta) => {
if let Some(store) = storage {
let mut w = store.lock().expect("Directory storage lock poisoned");
@ -334,12 +338,20 @@ impl<R: Runtime> DirState for GetConsensusState<R> {
}
impl<R: Runtime> GetConsensusState<R> {
/// Helper: try to set the current consensus text from an input
/// string `text`. Refuse it if the authorities could never be
/// correct, or if it is ill-formed.
/// Helper: try to set the current consensus text from an input string
/// `text`. Refuse it if the authorities could never be correct, or if it
/// is ill-formed.
///
/// If `cutoff` is provided, treat any consensus older than `cutoff` as
/// older-than-requested.
///
/// Errors from this method are not fatal to the download process.
fn add_consensus_text(&mut self, source: DocSource, text: &str) -> Result<&ConsensusMeta> {
fn add_consensus_text(
&mut self,
source: DocSource,
text: &str,
cutoff: Option<SystemTime>,
) -> Result<&ConsensusMeta> {
// Try to parse it and get its metadata.
let (consensus_meta, unvalidated) = {
let (signedval, remainder, parsed) =
@ -349,6 +361,11 @@ impl<R: Runtime> GetConsensusState<R> {
let parsed = self.config.tolerance.extend_tolerance(parsed);
let now = self.rt.wallclock();
let timely = parsed.check_valid_at(&now)?;
if let Some(cutoff) = cutoff {
if timely.peek_lifetime().valid_after() < cutoff {
return Err(Error::Unwanted("consensus was older than requested"));
}
}
let meta = ConsensusMeta::from_unvalidated(signedval, remainder, &timely);
(meta, timely)
};