commit 4d4e2abd2f961e735b9b8d93e9e09695515b8ac8 Author: Nick Mathewson nickm@torproject.org Date: Thu Aug 29 11:43:43 2019 -0400

Authorities reject relays running unsupported Tor release series.

Our minimum version is now 0.2.9.5-alpha. Series 0.3.0, 0.3.1, 0.3.2, 0.3.3, and 0.3.4 are now rejected.

Also, extract this version-checking code into a new function, so we can test it.

Closes ticket 31549.

Also reject 0.3.5.0 through 0.3.5.6-rc as unstable. --- changes/ticket31549 | 4 +++ src/feature/dirauth/process_descs.c | 59 +++++++++++++++++++++++++++---------- src/feature/dirauth/process_descs.h | 2 ++ 3 files changed, 49 insertions(+), 16 deletions(-)

diff --git a/changes/ticket31549 b/changes/ticket31549 new file mode 100644 index 000000000..2c27aca4f --- /dev/null +++ b/changes/ticket31549 @@ -0,0 +1,4 @@ + o Minor features (authority): + - Directory authorities now reject relays running all currently + deprecated release series. The currently supported release series + are: 0.2.9, 0.3.5, 0.4.0, 0.4.1, and 0.4.2. Closes ticket 31549. diff --git a/src/feature/dirauth/process_descs.c b/src/feature/dirauth/process_descs.c index e1a02179b..74a2cde1b 100644 --- a/src/feature/dirauth/process_descs.c +++ b/src/feature/dirauth/process_descs.c @@ -315,6 +315,47 @@ dirserv_would_reject_router(const routerstatus_t *rs) return (res & FP_REJECT) != 0; }

+/** + * Check whether the platform string in <b>platform</b> describes a platform + * that, as a directory authority, we want to reject. If it does, return + * true, and set *<b>msg</b> (if present) to a rejection message. Otherwise + * return false. + */ +STATIC bool +dirserv_rejects_tor_version(const char *platform, + const char **msg) +{ + if (!platform) + return false; + + static const char please_upgrade_string[] = + "Tor version is insecure or unsupported. Please upgrade!"; + + /* Versions before Tor 0.2.9 are unsupported. Versions between 0.2.9.0 and + * 0.2.9.4 suffer from bug #20499, where relays don't keep their consensus + * up to date */ + if (!tor_version_as_new_as(platform,"0.2.9.5-alpha")) { + if (msg) + *msg = please_upgrade_string; + return true; + } + + /* Series between Tor 0.3.0 and 0.3.4 inclusive are unsupported, and some + * have bug #27841, which makes them broken as intro points. Reject them. + * + * Also reject unstable versions of 0.3.5, since (as of this writing) + * they are almost none of the network. */ + if (tor_version_as_new_as(platform,"0.3.0.0-alpha-dev") && + !tor_version_as_new_as(platform,"0.3.5.7")) { + if (msg) { + *msg = please_upgrade_string; + } + return true; + } + + return false; +} + /** Helper: As dirserv_router_get_status, but takes the router fingerprint * (hex, no spaces), nickname, address (used for logging only), IP address, OR * port and platform (logging only) as arguments. @@ -347,22 +388,8 @@ dirserv_get_status_impl(const char *id_digest, const char *nickname, } }

- /* Versions before Tor 0.2.4.18-rc are too old to support, and are - * missing some important security fixes too. Disable them. */ - if (platform && !tor_version_as_new_as(platform,"0.2.4.18-rc")) { - if (msg) - *msg = "Tor version is insecure or unsupported. Please upgrade!"; - return FP_REJECT; - } - - /* Tor 0.2.9.x where x<5 suffers from bug #20499, where relays don't - * keep their consensus up to date so they make bad guards. - * The simple fix is to just drop them from the network. */ - if (platform && - tor_version_as_new_as(platform,"0.2.9.0-alpha") && - !tor_version_as_new_as(platform,"0.2.9.5-alpha")) { - if (msg) - *msg = "Tor version contains bug 20499. Please upgrade!"; + /* Check whether the version is obsolete, broken, insecure, etc... */ + if (platform && dirserv_rejects_tor_version(platform, msg)) { return FP_REJECT; }

diff --git a/src/feature/dirauth/process_descs.h b/src/feature/dirauth/process_descs.h index 1d4085b09..0203cebfa 100644 --- a/src/feature/dirauth/process_descs.h +++ b/src/feature/dirauth/process_descs.h @@ -38,6 +38,8 @@ int dirserv_would_reject_router(const routerstatus_t *rs);

#ifdef TOR_UNIT_TESTS STATIC int dirserv_router_has_valid_address(routerinfo_t *ri); +STATIC bool dirserv_rejects_tor_version(const char *platform, + const char **msg); #endif /* defined(TOR_UNIT_TESTS) */

#endif /* !defined(TOR_RECV_UPLOADS_H) */