Merge remote-tracking branch 'public/revert_4312'

src/common/compat_libevent.c

@@ -243,8 +243,8 @@ tor_libevent_initialize(tor_libevent_cfg *torcfg)
        * again. */
 #if defined(MS_WINDOWS) && defined(USE_BUFFEREVENTS)
       if (torcfg->disable_iocp == 0) {
-        log_warn(LD_GENERAL, "Unable to initialize Libevent. Trying again "
-                 "with IOCP disabled.");
+        log_warn(LD_GENERAL, "Unable to initialize Libevent. Trying again with "
+                 "IOCP disabled.");
       } else
 #endif
       {
@@ -254,6 +254,7 @@ tor_libevent_initialize(tor_libevent_cfg *torcfg)
       torcfg->disable_iocp = 1;
       goto retry;
     }
+
   }
 #else
   the_event_base = event_init();
@@ -558,60 +559,6 @@ tor_check_libevent_header_compatibility(void)
 #endif
 }
 
-struct tor_libevent_action_t {
-  struct event *ev;
-  void (*cb)(void *arg);
-  void *arg;
-};
-
-/** Callback for tor_run_in_libevent_loop */
-static void
-run_runnable_cb(evutil_socket_t s, short what, void *arg)
-{
-  tor_libevent_action_t *r = arg;
-  void (*cb)(void *) = r->cb;
-  void *cb_arg = r->arg;
-  (void)what;
-  (void)s;
-  tor_event_free(r->ev);
-  tor_free(r);
-
-  cb(cb_arg);
-}
-
-/** Cause cb(arg) to run later on this iteration of the libevent loop, or in
- * the next iteration of the libevent loop.  This is useful for when you're
- * deep inside a no-reentrant code and there's some function you want to call
- * without worrying about whether it might cause reeentrant invocation.
- */
-tor_libevent_action_t *
-tor_run_in_libevent_loop(void (*cb)(void *arg), void *arg)
-{
-  tor_libevent_action_t *r = tor_malloc(sizeof(tor_libevent_action_t));
-  r->cb = cb;
-  r->arg = arg;
-  r->ev = tor_event_new(tor_libevent_get_base(), -1, EV_TIMEOUT,
-                        run_runnable_cb, r);
-  if (!r->ev) {
-    tor_free(r);
-    return NULL;
-  }
-  /* Make the event active immediately. */
-  event_active(r->ev, EV_TIMEOUT, 1);
-
-  return r;
-}
-
-/**
- * Cancel <b>action</b> without running it.
- */
-void
-tor_cancel_libevent_action(tor_libevent_action_t *action)
-{
-  tor_event_free(action->ev);
-  tor_free(action);
-}
-
 /*
   If possible, we're going to try to use Libevent's periodic timer support,
   since it does a pretty good job of making sure that periodic events get

src/common/compat_libevent.h

@@ -44,12 +44,8 @@ void tor_event_free(struct event *ev);
 #define tor_evdns_add_server_port evdns_add_server_port
 #endif
 
-typedef struct tor_libevent_action_t tor_libevent_action_t;
-tor_libevent_action_t *tor_run_in_libevent_loop(void (*cb)(void *arg),
-                                                void *arg);
-void tor_cancel_libevent_action(tor_libevent_action_t *action);
-
 typedef struct periodic_timer_t periodic_timer_t;
+
 periodic_timer_t *periodic_timer_new(struct event_base *base,
              const struct timeval *tv,
              void (*cb)(periodic_timer_t *timer, void *data),

src/common/tortls.c

@@ -52,6 +52,7 @@
 #include <event2/bufferevent_ssl.h>
 #include <event2/buffer.h>
 #include <event2/event.h>
+#include "compat_libevent.h"
 #endif
 
 #define CRYPTO_PRIVATE /* to import prototypes from crypto.h */
@@ -63,7 +64,6 @@
 #include "torlog.h"
 #include "container.h"
 #include <string.h>
-#include "compat_libevent.h"
 
 /* Enable the "v2" TLS handshake.
  */
@@ -146,7 +146,7 @@ struct tor_tls_t {
   /** True iff we should call negotiated_callback when we're done reading. */
   unsigned int got_renegotiate:1;
   /** Incremented every time we start the server side of a handshake. */
-  unsigned int server_handshake_count:2;
+  uint8_t server_handshake_count;
   size_t wantwrite_n; /**< 0 normally, >0 if we returned wantwrite last
                        * time. */
   /** Last values retrieved from BIO_number_read()/write(); see
@@ -157,11 +157,6 @@ struct tor_tls_t {
   /** If set, a callback to invoke whenever the client tries to renegotiate
    * the handshake. */
   void (*negotiated_callback)(tor_tls_t *tls, void *arg);
-
-  /** Callback to invoke whenever a client tries to renegotiate more
-      than once. */
-  void (*excess_renegotiations_callback)(void *);
-
   /** Argument to pass to negotiated_callback. */
   void *callback_arg;
 };
@@ -585,8 +580,6 @@ tor_tls_create_certificate(crypto_pk_env_t *rsa,
                            const char *cname_sign,
                            unsigned int cert_lifetime)
 {
-  /* OpenSSL generates self-signed certificates with random 64-bit serial
-   * numbers, so let's do that too. */
 #define SERIAL_NUMBER_SIZE 8
 
   time_t start_time, end_time;
@@ -614,12 +607,12 @@ tor_tls_create_certificate(crypto_pk_env_t *rsa,
     goto error;
 
   { /* our serial number is 8 random bytes. */
-    if (crypto_rand((char *)serial_tmp, sizeof(serial_tmp)) < 0)
-      goto error;
-    if (!(serial_number = BN_bin2bn(serial_tmp, sizeof(serial_tmp), NULL)))
-      goto error;
-    if (!(BN_to_ASN1_INTEGER(serial_number, X509_get_serialNumber(x509))))
-      goto error;
+  if (crypto_rand((char *)serial_tmp, sizeof(serial_tmp)) < 0)
+    goto error;
+  if (!(serial_number = BN_bin2bn(serial_tmp, sizeof(serial_tmp), NULL)))
+    goto error;
+  if (!(BN_to_ASN1_INTEGER(serial_number, X509_get_serialNumber(x509))))
+    goto error;
   }
 
   if (!(name = tor_x509_name_new(cname)))
@@ -1319,42 +1312,55 @@ tor_tls_client_is_using_v2_ciphers(const SSL *ssl, const char *address)
   return 1;
 }
 
-/** We got an SSL ClientHello message.  This might mean that the
- * client wants to initiate a renegotiation and appropriate actions
- * must be taken. */
 static void
-tor_tls_got_client_hello(tor_tls_t *tls)
+tor_tls_debug_state_callback(const SSL *ssl, int type, int val)
 {
-  if (tls->server_handshake_count < 3)
-    ++tls->server_handshake_count;
+  log_debug(LD_HANDSHAKE, "SSL %p is now in state %s [type=%d,val=%d].",
+            ssl, ssl_state_to_string(ssl->state), type, val);
+}
 
-  if (tls->server_handshake_count == 2) {
-    if (!tls->negotiated_callback) {
-      log_warn(LD_BUG, "Got a renegotiation request but we don't"
-               " have a renegotiation callback set!");
-    }
+/** Invoked when we're accepting a connection on <b>ssl</b>, and the connection
+ * changes state. We use this:
+ * <ul><li>To alter the state of the handshake partway through, so we
+ *         do not send or request extra certificates in v2 handshakes.</li>
+ * <li>To detect renegotiation</li></ul>
+ */
+static void
+tor_tls_server_info_callback(const SSL *ssl, int type, int val)
+{
+  tor_tls_t *tls;
+  (void) val;
 
-    tls->got_renegotiate = 1;
-  } else if (tls->server_handshake_count > 2 &&
-             tls->excess_renegotiations_callback) {
-    /* We got more than one renegotiation requests. The Tor protocol
-       needs just one renegotiation; more than that probably means
-       They are trying to DoS us and we have to stop them. */
+  tor_tls_debug_state_callback(ssl, type, val);
 
-    tls->excess_renegotiations_callback(tls->callback_arg);
+  if (type != SSL_CB_ACCEPT_LOOP)
+    return;
+  if (ssl->state != SSL3_ST_SW_SRVR_HELLO_A)
+    return;
+
+  tls = tor_tls_get_by_ssl(ssl);
+  if (tls) {
+    /* Check whether we're watching for renegotiates.  If so, this is one! */
+    if (tls->negotiated_callback)
+      tls->got_renegotiate = 1;
+    if (tls->server_handshake_count < 127) /*avoid any overflow possibility*/
+      ++tls->server_handshake_count;
+  } else {
+    log_warn(LD_BUG, "Couldn't look up the tls for an SSL*. How odd!");
+    return;
   }
 
   /* Now check the cipher list. */
-  if (tor_tls_client_is_using_v2_ciphers(tls->ssl, ADDR(tls))) {
+  if (tor_tls_client_is_using_v2_ciphers(ssl, ADDR(tls))) {
     /*XXXX_TLS keep this from happening more than once! */
 
     /* Yes, we're casting away the const from ssl.  This is very naughty of us.
      * Let's hope openssl doesn't notice! */
 
     /* Set SSL_MODE_NO_AUTO_CHAIN to keep from sending back any extra certs. */
-    SSL_set_mode((SSL*) tls->ssl, SSL_MODE_NO_AUTO_CHAIN);
+    SSL_set_mode((SSL*) ssl, SSL_MODE_NO_AUTO_CHAIN);
     /* Don't send a hello request. */
-    SSL_set_verify((SSL*) tls->ssl, SSL_VERIFY_NONE, NULL);
+    SSL_set_verify((SSL*) ssl, SSL_VERIFY_NONE, NULL);
 
     if (tls) {
       tls->wasV2Handshake = 1;
@@ -1369,34 +1375,6 @@ tor_tls_got_client_hello(tor_tls_t *tls)
 }
 #endif
 
-/** This is a callback function for SSL_set_info_callback() and it
- *  will be called in every SSL state change.
- *  It logs the SSL state change, and executes any actions that must be
- *  taken.  */
-static void
-tor_tls_state_changed_callback(const SSL *ssl, int type, int val)
-{
-  log_debug(LD_HANDSHAKE, "SSL %p is now in state %s [type=%d,val=%d].",
-            ssl, ssl_state_to_string(ssl->state), type, val);
-
-#ifdef V2_HANDSHAKE_SERVER
-  if (type == SSL_CB_ACCEPT_LOOP &&
-      ssl->state == SSL3_ST_SW_SRVR_HELLO_A) {
-
-    /* Call tor_tls_got_client_hello() for every SSL ClientHello we
-       receive. */
-
-    tor_tls_t *tls = tor_tls_get_by_ssl(ssl);
-    if (!tls) {
-      log_warn(LD_BUG, "Couldn't look up the tls for an SSL*. How odd!");
-      return;
-    }
-
-    tor_tls_got_client_hello(tls);
-  }
-#endif
-}
-
 /** Replace *<b>ciphers</b> with a new list of SSL ciphersuites: specifically,
  * a list designed to mimic a common web browser.  Some of the ciphers in the
  * list won't actually be implemented by OpenSSL: that's okay so long as the
@@ -1538,8 +1516,14 @@ tor_tls_new(int sock, int isServer)
     log_warn(LD_NET, "Newly created BIO has read count %lu, write count %lu",
              result->last_read_count, result->last_write_count);
   }
-
-  SSL_set_info_callback(result->ssl, tor_tls_state_changed_callback);
+#ifdef V2_HANDSHAKE_SERVER
+  if (isServer) {
+    SSL_set_info_callback(result->ssl, tor_tls_server_info_callback);
+  } else
+#endif
+  {
+    SSL_set_info_callback(result->ssl, tor_tls_debug_state_callback);
+  }
 
   /* Not expected to get called. */
   tls_log_errors(NULL, LOG_WARN, LD_NET, "creating tor_tls_t object");
@@ -1557,22 +1541,25 @@ tor_tls_set_logged_address(tor_tls_t *tls, const char *address)
   tls->address = tor_strdup(address);
 }
 
-/** Set <b>cb</b> to be called with argument <b>arg</b> whenever
- * <b>tls</b> next gets a client-side renegotiate in the middle of a
- * read. Set <b>cb2</b> to be called with argument <b>arg</b> whenever
- * <b>tls</b> gets excess renegotiation requests.  Do not invoke this
- * function until <em>after</em> initial handshaking is done!
+/** Set <b>cb</b> to be called with argument <b>arg</b> whenever <b>tls</b>
+ * next gets a client-side renegotiate in the middle of a read.  Do not
+ * invoke this function until <em>after</em> initial handshaking is done!
  */
 void
-tor_tls_set_renegotiate_callbacks(tor_tls_t *tls,
+tor_tls_set_renegotiate_callback(tor_tls_t *tls,
                                  void (*cb)(tor_tls_t *, void *arg),
-                                 void (*cb2)(void *),
                                  void *arg)
 {
   tls->negotiated_callback = cb;
-  tls->excess_renegotiations_callback = cb2;
   tls->callback_arg = arg;
   tls->got_renegotiate = 0;
+#ifdef V2_HANDSHAKE_SERVER
+  if (cb) {
+    SSL_set_info_callback(tls->ssl, tor_tls_server_info_callback);
+  } else {
+    SSL_set_info_callback(tls->ssl, tor_tls_debug_state_callback);
+  }
+#endif
 }
 
 /** If this version of openssl requires it, turn on renegotiation on
@@ -1592,6 +1579,16 @@ tor_tls_unblock_renegotiation(tor_tls_t *tls)
   }
 }
 
+/** If this version of openssl supports it, turn off renegotiation on
+ * <b>tls</b>.  (Our protocol never requires this for security, but it's nice
+ * to use belt-and-suspenders here.)
+ */
+void
+tor_tls_block_renegotiation(tor_tls_t *tls)
+{
+  tls->ssl->s3->flags &= ~SSL3_FLAGS_ALLOW_UNSAFE_LEGACY_RENEGOTIATION;
+}
+
 void
 tor_tls_assert_renegotiation_unblocked(tor_tls_t *tls)
 {
@@ -1629,7 +1626,6 @@ tor_tls_free(tor_tls_t *tls)
   SSL_free(tls->ssl);
   tls->ssl = NULL;
   tls->negotiated_callback = NULL;
-  tls->excess_renegotiations_callback = NULL;
   if (tls->context)
     tor_tls_context_decref(tls->context);
   tor_free(tls->address);
@@ -1651,30 +1647,19 @@ tor_tls_read(tor_tls_t *tls, char *cp, size_t len)
   tor_assert(tls->state == TOR_TLS_ST_OPEN);
   tor_assert(len<INT_MAX);
   r = SSL_read(tls->ssl, cp, (int)len);
-  if (r > 0) /* return the number of characters read */
-    return r;
-
-  /* If we got here, SSL_read() did not go as expected. */
-
-  err = tor_tls_get_error(tls, r, CATCH_ZERO, "reading", LOG_DEBUG, LD_NET);
-
+  if (r > 0) {
 #ifdef V2_HANDSHAKE_SERVER
-  if (tls->got_renegotiate) {
-    if (tls->server_handshake_count != 2) {
-      log_warn(LD_BUG, "We did not notice renegotiation in a timely "
-               "fashion (%u)!", tls->server_handshake_count);
+    if (tls->got_renegotiate) {
+      /* Renegotiation happened! */
+      log_info(LD_NET, "Got a TLS renegotiation from %s", ADDR(tls));
+      if (tls->negotiated_callback)
+        tls->negotiated_callback(tls, tls->callback_arg);
+      tls->got_renegotiate = 0;
     }
-
-    /* Renegotiation happened! */
-    log_info(LD_NET, "Got a TLS renegotiation from %s", ADDR(tls));
-    if (tls->negotiated_callback)
-      tls->negotiated_callback(tls, tls->callback_arg);
-    tls->got_renegotiate = 0;
-
+#endif
     return r;
   }
-#endif
-
+  err = tor_tls_get_error(tls, r, CATCH_ZERO, "reading", LOG_DEBUG, LD_NET);
   if (err == _TOR_TLS_ZERORETURN || err == TOR_TLS_CLOSE) {
     log_debug(LD_NET,"read returned r=%d; TLS is closed",r);
     tls->state = TOR_TLS_ST_CLOSED;
@@ -1711,7 +1696,6 @@ tor_tls_write(tor_tls_t *tls, const char *cp, size_t n)
   }
   r = SSL_write(tls->ssl, cp, (int)n);
   err = tor_tls_get_error(tls, r, 0, "writing", LOG_INFO, LD_NET);
-
   if (err == TOR_TLS_DONE) {
     return r;
   }
@@ -1776,6 +1760,7 @@ tor_tls_finish_handshake(tor_tls_t *tls)
 {
   int r = TOR_TLS_DONE;
   if (tls->isServer) {
+    SSL_set_info_callback(tls->ssl, NULL);
     SSL_set_verify(tls->ssl, SSL_VERIFY_PEER, always_accept_verify_cb);
     /* There doesn't seem to be a clear OpenSSL API to clear mode flags. */
     tls->ssl->mode &= ~SSL_MODE_NO_AUTO_CHAIN;

src/common/tortls.h

@@ -13,7 +13,6 @@
 
 #include "crypto.h"
 #include "compat.h"
-#include "compat_libevent.h"
 
 /* Opaque structure to hold a TLS connection. */
 typedef struct tor_tls_t tor_tls_t;
@@ -61,9 +60,8 @@ int tor_tls_context_init(int is_public_server,
                          unsigned int key_lifetime);
 tor_tls_t *tor_tls_new(int sock, int is_server);
 void tor_tls_set_logged_address(tor_tls_t *tls, const char *address);
-void tor_tls_set_renegotiate_callbacks(tor_tls_t *tls,
+void tor_tls_set_renegotiate_callback(tor_tls_t *tls,
                                       void (*cb)(tor_tls_t *, void *arg),
-                                      void (*cb2)(void *),
                                       void *arg);
 int tor_tls_is_server(tor_tls_t *tls);
 void tor_tls_free(tor_tls_t *tls);
@@ -79,6 +77,7 @@ int tor_tls_handshake(tor_tls_t *tls);
 int tor_tls_finish_handshake(tor_tls_t *tls);
 int tor_tls_renegotiate(tor_tls_t *tls);
 void tor_tls_unblock_renegotiation(tor_tls_t *tls);
+void tor_tls_block_renegotiation(tor_tls_t *tls);
 void tor_tls_assert_renegotiation_unblocked(tor_tls_t *tls);
 int tor_tls_shutdown(tor_tls_t *tls);
 int tor_tls_get_pending_bytes(tor_tls_t *tls);

src/common/util.c

@@ -3661,8 +3661,8 @@ tor_get_exit_code(const process_handle_t *process_handle,
     /* Process has not exited */
     return PROCESS_EXIT_RUNNING;
   } else if (retval != process_handle->pid) {
-    log_warn(LD_GENERAL, "waitpid() failed for PID %d: %s",
-             process_handle->pid, strerror(errno));
+    log_warn(LD_GENERAL, "waitpid() failed for PID %d: %s", process_handle->pid,
+             strerror(errno));
     return PROCESS_EXIT_ERROR;
   }
 

src/or/connection_or.c

@@ -42,7 +42,6 @@ static int connection_or_check_valid_tls_handshake(or_connection_t *conn,
                                                    char *digest_rcvd_out);
 
 static void connection_or_tls_renegotiated_cb(tor_tls_t *tls, void *_conn);
-static void connection_or_close_connection_cb(void *_conn);
 
 #ifdef USE_BUFFEREVENTS
 static void connection_or_handle_event_cb(struct bufferevent *bufev,
@@ -493,9 +492,6 @@ connection_or_about_to_close(or_connection_t *or_conn)
   time_t now = time(NULL);
   connection_t *conn = TO_CONN(or_conn);
 
-  if (or_conn->pending_action)
-    tor_cancel_libevent_action(or_conn->pending_action);
-
   /* Remember why we're closing this connection. */
   if (conn->state != OR_CONN_STATE_OPEN) {
     /* Inform any pending (not attached) circs that they should
@@ -1103,16 +1099,12 @@ connection_tls_start_handshake(or_connection_t *conn, int receiving)
   conn->_base.state = OR_CONN_STATE_TLS_HANDSHAKING;
   tor_assert(!conn->tls);
   conn->tls = tor_tls_new(conn->_base.s, receiving);
+  tor_tls_set_logged_address(conn->tls, // XXX client and relay?
+      escaped_safe_str(conn->_base.address));
   if (!conn->tls) {
     log_warn(LD_BUG,"tor_tls_new failed. Closing.");
     return -1;
   }
-  tor_tls_set_logged_address(conn->tls, // XXX client and relay?
-      escaped_safe_str(conn->_base.address));
-  tor_tls_set_renegotiate_callbacks(conn->tls,
-                                    connection_or_tls_renegotiated_cb,
-                                    connection_or_close_connection_cb,
-                                    conn);
 #ifdef USE_BUFFEREVENTS
   if (connection_type_uses_bufferevent(TO_CONN(conn))) {
     const int filtering = get_options()->_UseFilteringSSLBufferevents;
@@ -1157,6 +1149,10 @@ connection_or_tls_renegotiated_cb(tor_tls_t *tls, void *_conn)
   or_connection_t *conn = _conn;
   (void)tls;
 
+  /* Don't invoke this again. */
+  tor_tls_set_renegotiate_callback(tls, NULL, NULL);
+  tor_tls_block_renegotiation(tls);
+
   if (connection_tls_finish_handshake(conn) < 0) {
     /* XXXX_TLS double-check that it's ok to do this from inside read. */
     /* XXXX_TLS double-check that this verifies certificates. */
@@ -1164,34 +1160,6 @@ connection_or_tls_renegotiated_cb(tor_tls_t *tls, void *_conn)
   }
 }
 
-/*DOCDOC*/
-static void
-close_connection_libevent_cb(void *_conn)
-{
-  or_connection_t *or_conn = _conn;
-  connection_t *conn = TO_CONN(or_conn);
-
-  or_conn->pending_action = NULL;
-
-  connection_stop_reading(conn);
-  if (!conn->marked_for_close)
-    connection_mark_for_close(conn);
-}
-
-/* DOCDOC */
-static void
-connection_or_close_connection_cb(void *_conn)
-{
-  /* We can't close their connection from in here since it's an OpenSSL
-     callback, so we set a libevent event that triggers in the next event
-     loop and closes the connection. */
-  or_connection_t *or_conn = _conn;
-  if (or_conn->_base.marked_for_close || or_conn->pending_action)
-    return;
-  or_conn->pending_action =
-    tor_run_in_libevent_loop(close_connection_libevent_cb, or_conn);
-}
-
 /** Move forward with the tls handshake. If it finishes, hand
  * <b>conn</b> to connection_tls_finish_handshake().
  *
@@ -1238,6 +1206,9 @@ connection_tls_continue_handshake(or_connection_t *conn)
           /* v2/v3 handshake, but not a client. */
           log_debug(LD_OR, "Done with initial SSL handshake (server-side). "
                            "Expecting renegotiation or VERSIONS cell");
+          tor_tls_set_renegotiate_callback(conn->tls,
+                                           connection_or_tls_renegotiated_cb,
+                                           conn);
           conn->_base.state = OR_CONN_STATE_TLS_SERVER_RENEGOTIATING;
           connection_stop_writing(TO_CONN(conn));
           connection_start_reading(TO_CONN(conn));
@@ -1298,6 +1269,9 @@ connection_or_handle_event_cb(struct bufferevent *bufev, short event,
       } else if (tor_tls_get_num_server_handshakes(conn->tls) == 1) {
         /* v2 or v3 handshake, as a server. Only got one handshake, so
          * wait for the next one. */
+        tor_tls_set_renegotiate_callback(conn->tls,
+                                         connection_or_tls_renegotiated_cb,
+                                         conn);
         conn->_base.state = OR_CONN_STATE_TLS_SERVER_RENEGOTIATING;
         /* return 0; */
         return; /* ???? */
@@ -1567,6 +1541,7 @@ connection_tls_finish_handshake(or_connection_t *conn)
       connection_or_init_conn_from_address(conn, &conn->_base.addr,
                                            conn->_base.port, digest_rcvd, 0);
     }
+    tor_tls_block_renegotiation(conn->tls);
     return connection_or_set_state_open(conn);
   } else {
     conn->_base.state = OR_CONN_STATE_OR_HANDSHAKING_V2;

src/or/or.h

@@ -1276,8 +1276,6 @@ typedef struct or_connection_t {
   unsigned active_circuit_pqueue_last_recalibrated;
   struct or_connection_t *next_with_same_id; /**< Next connection with same
                                               * identity digest as this one. */
-
-  tor_libevent_action_t *pending_action;
 } or_connection_t;
 
 /** Subtype of connection_t for an "edge connection" -- that is, an entry (ap)