resume being printist: if the hostname contains non-printable

characters, then fail. this time don't even bother telling the
server operator about these cases, because what's he going to do?

if it turns out that some significant population somewhere in the
world uses non-printable hostnames and wants to use tor, then i
hereby assume that they will contact us.


svn:r6171

2 files changed, 21 insertions, 1 deletions

diff --git a/src/or/buffers.c b/src/or/buffers.c
index 4bba6423d4..f07dc7d233 100644
--- a/src/or/buffers.c
+++ b/src/or/buffers.c
@@ -1003,7 +1003,13 @@ fetch_from_buf_socks(buf_t *buf, socks_request_t *req, int log_sockstype)
           req->address[len] = 0;
           req->port = ntohs(get_uint16(buf->cur+5+len));
           buf_remove_from_front(buf, 5+len+2);
-
+          if (!tor_strisprint(req->address) || strchr(req->address,'\"')) {
+            log_warn(LD_PROTOCOL,
+                     "Your application (using socks5 on port %d) gave Tor "
+                     "a malformed hostname: %s. Rejecting the connection.",
+                     req->port, escaped(req->address));
+            return -1;
+          }
           if (log_sockstype)
             log_notice(LD_APP,
                   "Your application (using socks5 on port %d) gave "
@@ -1098,6 +1104,13 @@ fetch_from_buf_socks(buf_t *buf, socks_request_t *req, int log_sockstype)
       log_debug(LD_APP,"socks4: Everything is here. Success.");
       strlcpy(req->address, startaddr ? startaddr : tmpbuf,
               sizeof(req->address));
+      if (!tor_strisprint(req->address) || strchr(req->address,'\"')) {
+        log_warn(LD_PROTOCOL,
+                 "Your application (using socks4 on port %d) gave Tor "
+                 "a malformed hostname: %s. Rejecting the connection.",
+                 req->port, escaped(req->address));
+        return -1;
+      }
       /* next points to the final \0 on inbuf */
       buf_remove_from_front(buf, next-buf->cur+1);
       return 1;
diff --git a/src/or/connection_edge.c b/src/or/connection_edge.c
index 1ad5ee4078..6b8b014b44 100644
--- a/src/or/connection_edge.c
+++ b/src/or/connection_edge.c
@@ -1533,6 +1533,13 @@ connection_exit_begin_conn(cell_t *cell, circuit_t *circ)
     tor_free(address);
     return 0;
   }
+  if (!tor_strisprint(address)) {
+    log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
+           "Non-printing characters in address %s in relay "
+           "begin cell. Dropping.", escaped(address));
+    tor_free(address);
+    return 0;
+  }
 
   log_debug(LD_EXIT,"Creating new exit connection.");
   n_stream = connection_new(CONN_TYPE_EXIT);