From 281a5e4670bfd4d687f58cf9999666a4d097e35e Mon Sep 17 00:00:00 2001 From: Nick Mathewson Date: Thu, 24 May 2012 12:39:26 -0400 Subject: Warn and ignore the MyFamily setting if BridgeRelay is also set Roger explains at http://archives.seul.org/tor/talk/Nov-2011/msg00209.html : "If you list your bridge as part of your family in the relay descriptor, then everybody can learn your bridge fingerprint, and they can look up your bridge's descriptor (and thus location) at the bridge directory authority." Now, we can't stop relays from listing bridges, but we can warn when we notice a bridge listing anybody, which might help some. This fixes bug 4657; it's a fix on 0.2.0.3-alpha, where bridges were first introduced. --- changes/bug4657 | 4 ++++ src/or/config.c | 6 ++++++ src/or/router.c | 2 +- 3 files changed, 11 insertions(+), 1 deletion(-) create mode 100644 changes/bug4657 diff --git a/changes/bug4657 b/changes/bug4657 new file mode 100644 index 0000000000..4d9dd7d0a3 --- /dev/null +++ b/changes/bug4657 @@ -0,0 +1,4 @@ + o Minor bugfixes: + - If the configuration tries to set MyFamily on a bridge, refuse to + do so, and warn about the security implications. Fix for bug 4657; + bugfix on 0.2.0.3-alpha. diff --git a/src/or/config.c b/src/or/config.c index 090aba1c7a..58c76b4fba 100644 --- a/src/or/config.c +++ b/src/or/config.c @@ -3601,6 +3601,12 @@ options_validate(or_options_t *old_options, or_options_t *options, if (options->UseEntryGuards && ! options->NumEntryGuards) REJECT("Cannot enable UseEntryGuards with NumEntryGuards set to 0"); + if (options->MyFamily && options->BridgeRelay) { + log_warn(LD_CONFIG, "Listing a family for a bridge relay is not " + "supported: it can reveal bridge fingerprints to censors. " + "You should also make sure you aren't listing this bridge's " + "fingerprint in any other MyFamily."); + } if (check_nickname_list(options->MyFamily, "MyFamily", msg)) return -1; for (cl = options->NodeFamilies; cl; cl = cl->next) { diff --git a/src/or/router.c b/src/or/router.c index 365e888af9..1919448152 100644 --- a/src/or/router.c +++ b/src/or/router.c @@ -1483,7 +1483,7 @@ router_rebuild_descriptor(int force) } if (authdir_mode(options)) ri->is_valid = ri->is_named = 1; /* believe in yourself */ - if (options->MyFamily) { + if (options->MyFamily && ! options->BridgeRelay) { smartlist_t *family; if (!warned_nonexistent_family) warned_nonexistent_family = smartlist_create(); -- cgit v1.2.3-54-g00ecf