commit 4c789ec08c8d52c3aab3ab775a86fe2350d584b5 Author: Sebastian Hahn <sebastian@torproject.org> Date: Tue Apr 26 05:07:37 2011 +0200 Don't leak the local hostname in relay nicknames Fixes bug 2979, reported by tagnaq. --- changes/bug2979 | 9 ++++++++ src/or/config.c | 55 ------------------------------------------------------ src/or/dirserv.h | 2 +- 3 files changed, 10 insertions(+), 56 deletions(-) diff --git a/changes/bug2979 b/changes/bug2979 new file mode 100644 index 0000000..fe1f45f --- /dev/null +++ b/changes/bug2979 @@ -0,0 +1,9 @@ + o Minor bugfixes: + - If the Nickname configuration option wasn't given, Tor used to pick + a nickname based on the local hostname as the nickname for a relay. + Because nicknames are not very important in today's Tor and the + "Unnamed" nickname has been implemented, this is now problematic + behaviour: It leaks information about the hostname without being + useful at all. Bugfix on tor-0.1.2.2-alpha, which introduced the + Unnamed nickname. Fixes bug 2979, reported by tagnaq. + diff --git a/src/or/config.c b/src/or/config.c index 3770301..9675c73 100644 --- a/src/or/config.c +++ b/src/or/config.c @@ -2500,54 +2500,6 @@ is_local_addr(const tor_addr_t *addr) return 0; } -/** Called when we don't have a nickname set. Try to guess a good nickname - * based on the hostname, and return it in a newly allocated string. If we - * can't, return NULL and let the caller warn if it wants to. */ -static char * -get_default_nickname(void) -{ - static const char * const bad_default_nicknames[] = { - "localhost", - NULL, - }; - char localhostname[256]; - char *cp, *out, *outp; - int i; - - if (gethostname(localhostname, sizeof(localhostname)) < 0) - return NULL; - - /* Put it in lowercase; stop at the first dot. */ - if ((cp = strchr(localhostname, '.'))) - *cp = '\0'; - tor_strlower(localhostname); - - /* Strip invalid characters. */ - cp = localhostname; - out = outp = tor_malloc(strlen(localhostname) + 1); - while (*cp) { - if (strchr(LEGAL_NICKNAME_CHARACTERS, *cp)) - *outp++ = *cp++; - else - cp++; - } - *outp = '\0'; - - /* Enforce length. */ - if (strlen(out) > MAX_NICKNAME_LEN) - out[MAX_NICKNAME_LEN]='\0'; - - /* Check for dumb names. */ - for (i = 0; bad_default_nicknames[i]; ++i) { - if (!strcmp(out, bad_default_nicknames[i])) { - tor_free(out); - return NULL; - } - } - - return out; -} - /** Release storage held by <b>options</b>. */ static void config_free(config_format_t *fmt, void *options) @@ -2976,14 +2928,7 @@ options_validate(or_options_t *old_options, or_options_t *options, if (options->Nickname == NULL) { if (server_mode(options)) { - if (!(options->Nickname = get_default_nickname())) { - log_notice(LD_CONFIG, "Couldn't pick a nickname based on " - "our hostname; using %s instead.", UNNAMED_ROUTER_NICKNAME); options->Nickname = tor_strdup(UNNAMED_ROUTER_NICKNAME); - } else { - log_notice(LD_CONFIG, "Choosing default nickname '%s'", - options->Nickname); - } } } else { if (!is_legal_nickname(options->Nickname)) { diff --git a/src/or/dirserv.h b/src/or/dirserv.h index 569abfc..a8a7060 100644 --- a/src/or/dirserv.h +++ b/src/or/dirserv.h @@ -52,7 +52,7 @@ MAX_V_LINE_LEN \ ) -#define UNNAMED_ROUTER_NICKNAME "Unnamed" +#define UNNAMED_ROUTER_NICKNAME "Unnamed" int connection_dirserv_flushed_some(dir_connection_t *conn);