socks: Returns 0xF6 only if BAD_HOSTNAME

This commit modifies the behavior of `parse_extended_address` in such a way
that if it fails, it will always return a `BAD_HOSTNAME` value, which is then
used to return the 0xF6 extended error code.  This way, in any case that is
not a valid v2 address, we return the 0xF6 error code, which is the expected
behavior.

Signed-off-by: David Goulet <dgoulet@torproject.org>

2 files changed, 11 insertions, 2 deletions

diff --git a/src/core/or/connection_edge.c b/src/core/or/connection_edge.c
index fc77db8334..26595003c1 100644
--- a/src/core/or/connection_edge.c
+++ b/src/core/or/connection_edge.c
@@ -1663,6 +1663,9 @@ parse_extended_hostname(char *address, hostname_type_t *type_out)
   log_warn(LD_APP, "Invalid %shostname %s; rejecting",
            is_onion ? "onion " : "",
            safe_str_client(address));
+  if (*type_out == ONION_V3_HOSTNAME) {
+      *type_out = BAD_HOSTNAME;
+  }
   return false;
 }
 
@@ -2139,7 +2142,7 @@ connection_ap_handshake_rewrite_and_attach(entry_connection_t *conn,
   if (!parse_extended_hostname(socks->address, &addresstype)) {
     control_event_client_status(LOG_WARN, "SOCKS_BAD_HOSTNAME HOSTNAME=%s",
                                 escaped(socks->address));
-    if (addresstype == ONION_V3_HOSTNAME) {
+    if (addresstype == BAD_HOSTNAME) {
       conn->socks_request->socks_extended_error_code = SOCKS5_HS_BAD_ADDRESS;
     }
     connection_mark_unattached_ap(conn, END_STREAM_REASON_TORPROTOCOL);
diff --git a/src/test/test_hs_common.c b/src/test/test_hs_common.c
index 4a161db334..9202074e25 100644
--- a/src/test/test_hs_common.c
+++ b/src/test/test_hs_common.c
@@ -792,6 +792,8 @@ test_parse_extended_hostname(void *arg)
     "www.25njqamcweflpvkl73j4szahhihoc4xt3ktcgjnpaingr5yhkenl5sid.onion";
   char address9[] =
     "www.15njqamcweflpvkl73j4szahhihoc4xt3ktcgjnpaingr5yhkenl5sid.onion";
+  char address10[] =
+    "15njqamcweflpvkl73j4szahhihoc4xt3ktcgjnpaingr5yhkenl5sid7jdl.onion";
 
   tt_assert(!parse_extended_hostname(address1, &type));
   tt_int_op(type, OP_EQ, BAD_HOSTNAME);
@@ -824,7 +826,11 @@ test_parse_extended_hostname(void *arg)
 
   /* Invalid v3 address. */
   tt_assert(!parse_extended_hostname(address9, &type));
-  tt_int_op(type, OP_EQ, ONION_V3_HOSTNAME);
+  tt_int_op(type, OP_EQ, BAD_HOSTNAME);
+
+  /* Invalid v3 address: too long */
+  tt_assert(!parse_extended_hostname(address10, &type));
+  tt_int_op(type, OP_EQ, BAD_HOSTNAME);
 
  done: ;
 }