Remove AllowDotExit.

It's been deprecated since 0.2.9.2-alpha.  Closes ticket 23426.

6 files changed, 22 insertions, 58 deletions

diff --git a/changes/bug23426 b/changes/bug23426
new file mode 100644
index 0000000000..63c127c539
--- /dev/null
+++ b/changes/bug23426
@@ -0,0 +1,4 @@
+  o Removed features:
+    - The AllowDotExit option has been removed as unsafe.  It has
+      been deprecated since 0.2.9.2-alpha.  Closes ticket 23426.
+
diff --git a/doc/tor.1.txt b/doc/tor.1.txt
index aec1767059..7b67ab9ad1 100644
--- a/doc/tor.1.txt
+++ b/doc/tor.1.txt
@@ -924,7 +924,7 @@ The following options are useful only for clients (that is, if
     The ExcludeNodes option overrides this option: any node listed in both
     ExitNodes and ExcludeNodes is treated as excluded. +
  +
-    The .exit address notation, if enabled via AllowDotExit, overrides
+    The .exit address notation, if enabled via MapAddress, overrides
     this option.
 
 [[EntryNodes]] **EntryNodes** __node__,__node__,__...__::
@@ -1328,12 +1328,6 @@ The following options are useful only for clients (that is, if
     resolved. This helps trap accidental attempts to resolve URLs and so on.
     (Default: 0)
 
-[[AllowDotExit]] **AllowDotExit** **0**|**1**::
-    If enabled, we convert "www.google.com.foo.exit" addresses on the
-    SocksPort/TransPort/NATDPort into "www.google.com" addresses that exit from
-    the node "foo". Disabled by default since attacking websites and exit
-    relays can use it to manipulate your path selection. (Default: 0)
-
 [[HTTPTunnelPort]] **HTTPTunnelPort**  \['address':]__port__|**auto** [_isolation flags_]::
     Open this port to listen for proxy connections using the "HTTP CONNECT"
     protocol instead of SOCKS. Set this to 0
diff --git a/src/or/config.c b/src/or/config.c
index eb89d6f5ee..d2c076b712 100644
--- a/src/or/config.c
+++ b/src/or/config.c
@@ -206,7 +206,7 @@ static config_var_t option_vars_[] = {
   VAR("AccountingRule",          STRING,   AccountingRule_option,  "max"),
   V(AccountingStart,             STRING,   NULL),
   V(Address,                     STRING,   NULL),
-  V(AllowDotExit,                BOOL,     "0"),
+  OBSOLETE("AllowDotExit"),
   OBSOLETE("AllowInvalidNodes"),
   V(AllowNonRFC953Hostnames,     BOOL,     "0"),
   OBSOLETE("AllowSingleHopCircuits"),
@@ -671,8 +671,6 @@ static const config_var_t testing_tor_network_defaults[] = {
 
 static const config_deprecation_t option_deprecation_notes_[] = {
   /* Deprecated since 0.2.9.2-alpha... */
-  { "AllowDotExit", "Unrestricted use of the .exit notation can be used for "
-    "a wide variety of application-level attacks." },
   { "ClientDNSRejectInternalAddresses", "Turning this on makes your client "
     "easier to fingerprint, and may open you to esoteric attacks." },
   /* End of options deprecated since 0.2.9.2-alpha. */
diff --git a/src/or/connection_edge.c b/src/or/connection_edge.c
index a9fdeee0ee..37d82e2ae0 100644
--- a/src/or/connection_edge.c
+++ b/src/or/connection_edge.c
@@ -1235,10 +1235,9 @@ connection_ap_handshake_rewrite(entry_connection_t *conn,
   /* Check for whether this is a .exit address.  By default, those are
    * disallowed when they're coming straight from the client, but you're
    * allowed to have them in MapAddress commands and so forth. */
-  if (!strcmpend(socks->address, ".exit") && !options->AllowDotExit) {
+  if (!strcmpend(socks->address, ".exit")) {
     log_warn(LD_APP, "The  \".exit\" notation is disabled in Tor due to "
-             "security risks. Set AllowDotExit in your torrc to enable "
-             "it (at your own risk).");
+             "security risks.");
     control_event_client_status(LOG_WARN, "SOCKS_BAD_HOSTNAME HOSTNAME=%s",
                                 escaped(socks->address));
     out->end_reason = END_STREAM_REASON_TORPROTOCOL;
@@ -1653,23 +1652,23 @@ connection_ap_handshake_rewrite_and_attach(entry_connection_t *conn,
     const node_t *node = NULL;
 
     /* If this .exit was added by an AUTOMAP, then it came straight from
-     * a user.  Make sure that options->AllowDotExit permits that! */
-    if (exit_source == ADDRMAPSRC_AUTOMAP && !options->AllowDotExit) {
-      /* Whoops; this one is stale.  It must have gotten added earlier,
-       * when AllowDotExit was on. */
-      log_warn(LD_APP,"Stale automapped address for '%s.exit', with "
-               "AllowDotExit disabled. Refusing.",
+     * a user.  That's not safe. */
+    if (exit_source == ADDRMAPSRC_AUTOMAP) {
+      /* Whoops; this one is stale.  It must have gotten added earlier?
+       * (Probably this is not possible, since AllowDotExit no longer
+       * exists.) */
+      log_warn(LD_APP,"Stale automapped address for '%s.exit'. Refusing.",
                safe_str_client(socks->address));
       control_event_client_status(LOG_WARN, "SOCKS_BAD_HOSTNAME HOSTNAME=%s",
                                   escaped(socks->address));
       connection_mark_unattached_ap(conn, END_STREAM_REASON_TORPROTOCOL);
+      tor_assert_nonfatal_unreached();
       return -1;
     }
 
     /* Double-check to make sure there are no .exits coming from
      * impossible/weird sources. */
-    if (exit_source == ADDRMAPSRC_DNS ||
-        (exit_source == ADDRMAPSRC_NONE && !options->AllowDotExit)) {
+    if (exit_source == ADDRMAPSRC_DNS || exit_source == ADDRMAPSRC_NONE) {
       /* It shouldn't be possible to get a .exit address from any of these
        * sources. */
       log_warn(LD_BUG,"Address '%s.exit', with impossible source for the "
diff --git a/src/or/or.h b/src/or/or.h
index 5a543b498c..b445d48088 100644
--- a/src/or/or.h
+++ b/src/or/or.h
@@ -4160,13 +4160,6 @@ typedef struct {
    * if we are a cache).  For authorities, this is always true. */
   int DownloadExtraInfo;
 
-  /** If true, we convert "www.google.com.foo.exit" addresses on the
-   * socks/trans/natd ports into "www.google.com" addresses that
-   * exit from the node "foo". Disabled by default since attacking
-   * websites and exit relays can use it to manipulate your path
-   * selection. */
-  int AllowDotExit;
-
   /** If true, we're configured to collect statistics on clients
    * requesting network statuses from us as directory. */
   int DirReqStatistics_option;
diff --git a/src/test/test_entryconn.c b/src/test/test_entryconn.c
index 9fe3db26f7..b2c95f41eb 100644
--- a/src/test/test_entryconn.c
+++ b/src/test/test_entryconn.c
@@ -76,7 +76,6 @@ test_entryconn_rewrite_bad_dotexit(void *arg)
   entry_connection_t *ec = arg;
   rewrite_result_t rr;
 
-  get_options_mutable()->AllowDotExit = 0;
   tt_assert(ec->socks_request);
   strlcpy(ec->socks_request->address, "www.TORproject.org.foo.exit",
           sizeof(ec->socks_request->address));
@@ -480,7 +479,7 @@ test_entryconn_rewrite_reject_internal_reverse(void *arg)
   ;
 }
 
-/* Rewrite into .exit because of virtual address mapping */
+/* Rewrite into .exit because of virtual address mapping.  */
 static void
 test_entryconn_rewrite_automap_exit(void *arg)
 {
@@ -491,43 +490,21 @@ test_entryconn_rewrite_automap_exit(void *arg)
 
   ec2 = entry_connection_new(CONN_TYPE_AP, AF_INET);
 
-  get_options_mutable()->AutomapHostsOnResolve = 1;
-  get_options_mutable()->AllowDotExit = 1;
   smartlist_add_strdup(get_options_mutable()->AutomapHostsSuffixes,
                 ".EXIT");
   parse_virtual_addr_network("127.1.0.0/16", AF_INET, 0, &msg);
 
-  /* Automap this on resolve. */
+  /* Try to automap this on resolve. */
   strlcpy(ec->socks_request->address, "website.example.exit",
           sizeof(ec->socks_request->address));
   ec->socks_request->command = SOCKS_COMMAND_RESOLVE;
   connection_ap_handshake_rewrite(ec, &rr);
 
-  tt_int_op(rr.automap, OP_EQ, 1);
-  tt_int_op(rr.should_close, OP_EQ, 0);
-  tt_int_op(rr.end_reason, OP_EQ, 0);
-  tt_i64_op(rr.map_expires, OP_EQ, TIME_MAX);
-  tt_int_op(rr.exit_source, OP_EQ, ADDRMAPSRC_NONE);
-  tt_str_op(rr.orig_address, OP_EQ, "website.example.exit");
-  tt_str_op(ec->original_dest_address, OP_EQ, "website.example.exit");
-
-  tt_assert(!strcmpstart(ec->socks_request->address,"127.1."));
-
-  /* Connect to it and make sure we get the original address back. */
-  strlcpy(ec2->socks_request->address, ec->socks_request->address,
-          sizeof(ec2->socks_request->address));
-
-  ec2->socks_request->command = SOCKS_COMMAND_CONNECT;
-  connection_ap_handshake_rewrite(ec2, &rr);
-
+  /* Make sure it isn't allowed -- there is no longer an AllowDotExit
+   * option. */
   tt_int_op(rr.automap, OP_EQ, 0);
-  tt_int_op(rr.should_close, OP_EQ, 0);
-  tt_int_op(rr.end_reason, OP_EQ, 0);
-  tt_i64_op(rr.map_expires, OP_EQ, TIME_MAX);
-  tt_int_op(rr.exit_source, OP_EQ, ADDRMAPSRC_AUTOMAP);
-  tt_str_op(rr.orig_address, OP_EQ, ec->socks_request->address);
-  tt_str_op(ec2->original_dest_address, OP_EQ, ec->socks_request->address);
-  tt_str_op(ec2->socks_request->address, OP_EQ, "website.example.exit");
+  tt_int_op(rr.should_close, OP_EQ, 1);
+  tt_int_op(rr.end_reason, OP_EQ, END_STREAM_REASON_TORPROTOCOL);
 
  done:
   connection_free_(ENTRY_TO_CONN(ec2));
@@ -577,7 +554,6 @@ test_entryconn_rewrite_mapaddress_automap_onion(void *arg)
   ec4 = entry_connection_new(CONN_TYPE_AP, AF_INET);
 
   get_options_mutable()->AutomapHostsOnResolve = 1;
-  get_options_mutable()->AllowDotExit = 1;
   smartlist_add_strdup(get_options_mutable()->AutomapHostsSuffixes,
                 ".onion");
   parse_virtual_addr_network("192.168.0.0/16", AF_INET, 0, &msg);