commit ca6ccd372f8f56c842dfad8203bace99be580b90 Author: Nick Mathewson nickm@torproject.org Date: Mon Jan 11 14:50:40 2021 -0500

Reject obsolete router/extrainfo descs more quietly.

Thanks to proposal 315 / ticket #30132, more fields are now required in these documents. But ancient Tors that try to upload obsolete documents were causing the authorities to log warnings about missing fields, and to do so very spammily.

We now detect the missing fields before tokenizing, and log at debug. This is a bit of ugliness, but it's probably a safer choice than making _all_ unparseable-desc warnings into debug-level logs.

I'm looking at identity-ed25519 in extrainfos and proto in routerdescs because they were (I believe) the latest-added fields in Tor's history: any Tor that lacks them will also lack the other newly required fields.

Fixes bug #40238; bugfix on 0.4.5.1-alpha. --- src/feature/dirparse/routerparse.c | 11 +++++++++++ 1 file changed, 11 insertions(+)

diff --git a/src/feature/dirparse/routerparse.c b/src/feature/dirparse/routerparse.c index 635fc4b49d..3d90c1bc91 100644 --- a/src/feature/dirparse/routerparse.c +++ b/src/feature/dirparse/routerparse.c @@ -456,6 +456,12 @@ router_parse_entry_from_string(const char *s, const char *end, } }

+ if (!tor_memstr(s, end-s, "\nproto ")) { + log_debug(LD_DIR, "Found an obsolete router descriptor. " + "Rejecting quietly."); + goto err; + } + if (router_get_router_hash(s, end - s, digest) < 0) { log_warn(LD_DIR, "Couldn't compute router hash."); goto err; @@ -991,6 +997,11 @@ extrainfo_parse_entry_from_string(const char *s, const char *end, while (end > s+2 && *(end-1) == '\n' && *(end-2) == '\n') --end;

+ if (!tor_memstr(s, end-s, "\nidentity-ed25519")) { + log_debug(LD_DIR, "Found an obsolete extrainfo. Rejecting quietly."); + goto err; + } + if (router_get_extrainfo_hash(s, end-s, digest) < 0) { log_warn(LD_DIR, "Couldn't compute router hash."); goto err;