commit bc9492a938f0bc2ee8dfb6f94f0f8d81f16b9575
Merge: 1dd952789 0849d2a2f
Author: Nick Mathewson <nickm(a)torproject.org>
Date: Tue Aug 6 11:15:20 2019 -0400
Merge branch 'ticket31343_029' into ticket31343_035
changes/bug31343 | 9 +++++++++
src/core/or/channeltls.c | 24 ++++++++++++++++++++----
2 files changed, 29 insertions(+), 4 deletions(-)
diff --cc src/core/or/channeltls.c
index a83d54ed3,000000000..91a424728
mode 100644,000000..100644
--- a/src/core/or/channeltls.c
+++ b/src/core/or/channeltls.c
@@@ -1,2461 -1,0 +1,2477 @@@
+/* * Copyright (c) 2012-2019, The Tor Project, Inc. */
+/* See LICENSE for licensing information */
+
+/**
+ * \file channeltls.c
+ *
+ * \brief A concrete subclass of channel_t using or_connection_t to transfer
+ * cells between Tor instances.
+ *
+ * This module fills in the various function pointers in channel_t, to
+ * implement the channel_tls_t channels as used in Tor today. These channels
+ * are created from channel_tls_connect() and
+ * channel_tls_handle_incoming(). Each corresponds 1:1 to or_connection_t
+ * object, as implemented in connection_or.c. These channels transmit cells
+ * to the underlying or_connection_t by calling
+ * connection_or_write_*_cell_to_buf(), and receive cells from the underlying
+ * or_connection_t when connection_or_process_cells_from_inbuf() calls
+ * channel_tls_handle_*_cell().
+ *
+ * Here we also implement the server (responder) side of the v3+ Tor link
+ * handshake, which uses CERTS and AUTHENTICATE cell to negotiate versions,
+ * exchange expected and observed IP and time information, and bootstrap a
+ * level of authentication higher than we have gotten on the raw TLS
+ * handshake.
+ *
+ * NOTE: Since there is currently only one type of channel, there are probably
+ * more than a few cases where functionality that is currently in
+ * channeltls.c, connection_or.c, and channel.c ought to be divided up
+ * differently. The right time to do this is probably whenever we introduce
+ * our next channel type.
+ **/
+
+/*
+ * Define this so channel.h gives us things only channel_t subclasses
+ * should touch.
+ */
+#define TOR_CHANNEL_INTERNAL_
+
+#define CHANNELTLS_PRIVATE
+
+#include "core/or/or.h"
+#include "core/or/channel.h"
+#include "core/or/channeltls.h"
+#include "core/or/circuitmux.h"
+#include "core/or/circuitmux_ewma.h"
+#include "core/or/command.h"
+#include "app/config/config.h"
+#include "core/mainloop/connection.h"
+#include "core/or/connection_or.h"
+#include "feature/control/control.h"
+#include "feature/client/entrynodes.h"
+#include "trunnel/link_handshake.h"
+#include "core/or/relay.h"
+#include "feature/stats/rephist.h"
+#include "feature/relay/router.h"
+#include "feature/relay/routermode.h"
+#include "feature/nodelist/dirlist.h"
+#include "core/or/scheduler.h"
+#include "feature/nodelist/torcert.h"
+#include "feature/nodelist/networkstatus.h"
+#include "trunnel/channelpadding_negotiation.h"
+#include "core/or/channelpadding.h"
+
+#include "core/or/cell_st.h"
+#include "core/or/cell_queue_st.h"
+#include "core/or/extend_info_st.h"
+#include "core/or/or_connection_st.h"
+#include "core/or/or_handshake_certs_st.h"
+#include "core/or/or_handshake_state_st.h"
+#include "feature/nodelist/routerinfo_st.h"
+#include "core/or/var_cell_st.h"
+
+#include "lib/tls/tortls.h"
+#include "lib/tls/x509.h"
+
+/** How many CELL_PADDING cells have we received, ever? */
+uint64_t stats_n_padding_cells_processed = 0;
+/** How many CELL_VERSIONS cells have we received, ever? */
+uint64_t stats_n_versions_cells_processed = 0;
+/** How many CELL_NETINFO cells have we received, ever? */
+uint64_t stats_n_netinfo_cells_processed = 0;
+/** How many CELL_VPADDING cells have we received, ever? */
+uint64_t stats_n_vpadding_cells_processed = 0;
+/** How many CELL_CERTS cells have we received, ever? */
+uint64_t stats_n_certs_cells_processed = 0;
+/** How many CELL_AUTH_CHALLENGE cells have we received, ever? */
+uint64_t stats_n_auth_challenge_cells_processed = 0;
+/** How many CELL_AUTHENTICATE cells have we received, ever? */
+uint64_t stats_n_authenticate_cells_processed = 0;
+/** How many CELL_AUTHORIZE cells have we received, ever? */
+uint64_t stats_n_authorize_cells_processed = 0;
+
+/** Active listener, if any */
+static channel_listener_t *channel_tls_listener = NULL;
+
+/* channel_tls_t method declarations */
+
+static void channel_tls_close_method(channel_t *chan);
+static const char * channel_tls_describe_transport_method(channel_t *chan);
+static void channel_tls_free_method(channel_t *chan);
+static double channel_tls_get_overhead_estimate_method(channel_t *chan);
+static int
+channel_tls_get_remote_addr_method(channel_t *chan, tor_addr_t *addr_out);
+static int
+channel_tls_get_transport_name_method(channel_t *chan, char **transport_out);
+static const char *
+channel_tls_get_remote_descr_method(channel_t *chan, int flags);
+static int channel_tls_has_queued_writes_method(channel_t *chan);
+static int channel_tls_is_canonical_method(channel_t *chan, int req);
+static int
+channel_tls_matches_extend_info_method(channel_t *chan,
+ extend_info_t *extend_info);
+static int channel_tls_matches_target_method(channel_t *chan,
+ const tor_addr_t *target);
+static int channel_tls_num_cells_writeable_method(channel_t *chan);
+static size_t channel_tls_num_bytes_queued_method(channel_t *chan);
+static int channel_tls_write_cell_method(channel_t *chan,
+ cell_t *cell);
+static int channel_tls_write_packed_cell_method(channel_t *chan,
+ packed_cell_t *packed_cell);
+static int channel_tls_write_var_cell_method(channel_t *chan,
+ var_cell_t *var_cell);
+
+/* channel_listener_tls_t method declarations */
+
+static void channel_tls_listener_close_method(channel_listener_t *chan_l);
+static const char *
+channel_tls_listener_describe_transport_method(channel_listener_t *chan_l);
+
+/** Handle incoming cells for the handshake stuff here rather than
+ * passing them on up. */
+
+static void channel_tls_process_versions_cell(var_cell_t *cell,
+ channel_tls_t *tlschan);
+static void channel_tls_process_netinfo_cell(cell_t *cell,
+ channel_tls_t *tlschan);
+static int command_allowed_before_handshake(uint8_t command);
+static int enter_v3_handshake_with_cell(var_cell_t *cell,
+ channel_tls_t *tlschan);
+static void channel_tls_process_padding_negotiate_cell(cell_t *cell,
+ channel_tls_t *chan);
+
+/**
+ * Do parts of channel_tls_t initialization common to channel_tls_connect()
+ * and channel_tls_handle_incoming().
+ */
+STATIC void
+channel_tls_common_init(channel_tls_t *tlschan)
+{
+ channel_t *chan;
+
+ tor_assert(tlschan);
+
+ chan = &(tlschan->base_);
+ channel_init(chan);
+ chan->magic = TLS_CHAN_MAGIC;
+ chan->state = CHANNEL_STATE_OPENING;
+ chan->close = channel_tls_close_method;
+ chan->describe_transport = channel_tls_describe_transport_method;
+ chan->free_fn = channel_tls_free_method;
+ chan->get_overhead_estimate = channel_tls_get_overhead_estimate_method;
+ chan->get_remote_addr = channel_tls_get_remote_addr_method;
+ chan->get_remote_descr = channel_tls_get_remote_descr_method;
+ chan->get_transport_name = channel_tls_get_transport_name_method;
+ chan->has_queued_writes = channel_tls_has_queued_writes_method;
+ chan->is_canonical = channel_tls_is_canonical_method;
+ chan->matches_extend_info = channel_tls_matches_extend_info_method;
+ chan->matches_target = channel_tls_matches_target_method;
+ chan->num_bytes_queued = channel_tls_num_bytes_queued_method;
+ chan->num_cells_writeable = channel_tls_num_cells_writeable_method;
+ chan->write_cell = channel_tls_write_cell_method;
+ chan->write_packed_cell = channel_tls_write_packed_cell_method;
+ chan->write_var_cell = channel_tls_write_var_cell_method;
+
+ chan->cmux = circuitmux_alloc();
+ /* We only have one policy for now so always set it to EWMA. */
+ circuitmux_set_policy(chan->cmux, &ewma_policy);
+}
+
+/**
+ * Start a new TLS channel.
+ *
+ * Launch a new OR connection to <b>addr</b>:<b>port</b> and expect to
+ * handshake with an OR with identity digest <b>id_digest</b>, and wrap
+ * it in a channel_tls_t.
+ */
+channel_t *
+channel_tls_connect(const tor_addr_t *addr, uint16_t port,
+ const char *id_digest,
+ const ed25519_public_key_t *ed_id)
+{
+ channel_tls_t *tlschan = tor_malloc_zero(sizeof(*tlschan));
+ channel_t *chan = &(tlschan->base_);
+
+ channel_tls_common_init(tlschan);
+
+ log_debug(LD_CHANNEL,
+ "In channel_tls_connect() for channel %p "
+ "(global id %"PRIu64 ")",
+ tlschan,
+ (chan->global_identifier));
+
+ if (is_local_addr(addr)) {
+ log_debug(LD_CHANNEL,
+ "Marking new outgoing channel %"PRIu64 " at %p as local",
+ (chan->global_identifier), chan);
+ channel_mark_local(chan);
+ } else {
+ log_debug(LD_CHANNEL,
+ "Marking new outgoing channel %"PRIu64 " at %p as remote",
+ (chan->global_identifier), chan);
+ channel_mark_remote(chan);
+ }
+
+ channel_mark_outgoing(chan);
+
+ /* Set up or_connection stuff */
+ tlschan->conn = connection_or_connect(addr, port, id_digest, ed_id, tlschan);
+ /* connection_or_connect() will fill in tlschan->conn */
+ if (!(tlschan->conn)) {
+ chan->reason_for_closing = CHANNEL_CLOSE_FOR_ERROR;
+ channel_change_state(chan, CHANNEL_STATE_ERROR);
+ goto err;
+ }
+
+ log_debug(LD_CHANNEL,
+ "Got orconn %p for channel with global id %"PRIu64,
+ tlschan->conn, (chan->global_identifier));
+
+ goto done;
+
+ err:
+ circuitmux_free(chan->cmux);
+ tor_free(tlschan);
+ chan = NULL;
+
+ done:
+ /* If we got one, we should register it */
+ if (chan) channel_register(chan);
+
+ return chan;
+}
+
+/**
+ * Return the current channel_tls_t listener.
+ *
+ * Returns the current channel listener for incoming TLS connections, or
+ * NULL if none has been established
+ */
+channel_listener_t *
+channel_tls_get_listener(void)
+{
+ return channel_tls_listener;
+}
+
+/**
+ * Start a channel_tls_t listener if necessary.
+ *
+ * Return the current channel_tls_t listener, or start one if we haven't yet,
+ * and return that.
+ */
+channel_listener_t *
+channel_tls_start_listener(void)
+{
+ channel_listener_t *listener;
+
+ if (!channel_tls_listener) {
+ listener = tor_malloc_zero(sizeof(*listener));
+ channel_init_listener(listener);
+ listener->state = CHANNEL_LISTENER_STATE_LISTENING;
+ listener->close = channel_tls_listener_close_method;
+ listener->describe_transport =
+ channel_tls_listener_describe_transport_method;
+
+ channel_tls_listener = listener;
+
+ log_debug(LD_CHANNEL,
+ "Starting TLS channel listener %p with global id %"PRIu64,
+ listener, (listener->global_identifier));
+
+ channel_listener_register(listener);
+ } else listener = channel_tls_listener;
+
+ return listener;
+}
+
+/**
+ * Free everything on shutdown.
+ *
+ * Not much to do here, since channel_free_all() takes care of a lot, but let's
+ * get rid of the listener.
+ */
+void
+channel_tls_free_all(void)
+{
+ channel_listener_t *old_listener = NULL;
+
+ log_debug(LD_CHANNEL,
+ "Shutting down TLS channels...");
+
+ if (channel_tls_listener) {
+ /*
+ * When we close it, channel_tls_listener will get nulled out, so save
+ * a pointer so we can free it.
+ */
+ old_listener = channel_tls_listener;
+ log_debug(LD_CHANNEL,
+ "Closing channel_tls_listener with ID %"PRIu64
+ " at %p.",
+ (old_listener->global_identifier),
+ old_listener);
+ channel_listener_unregister(old_listener);
+ channel_listener_mark_for_close(old_listener);
+ channel_listener_free(old_listener);
+ tor_assert(channel_tls_listener == NULL);
+ }
+
+ log_debug(LD_CHANNEL,
+ "Done shutting down TLS channels");
+}
+
+/**
+ * Create a new channel around an incoming or_connection_t.
+ */
+channel_t *
+channel_tls_handle_incoming(or_connection_t *orconn)
+{
+ channel_tls_t *tlschan = tor_malloc_zero(sizeof(*tlschan));
+ channel_t *chan = &(tlschan->base_);
+
+ tor_assert(orconn);
+ tor_assert(!(orconn->chan));
+
+ channel_tls_common_init(tlschan);
+
+ /* Link the channel and orconn to each other */
+ tlschan->conn = orconn;
+ orconn->chan = tlschan;
+
+ if (is_local_addr(&(TO_CONN(orconn)->addr))) {
+ log_debug(LD_CHANNEL,
+ "Marking new incoming channel %"PRIu64 " at %p as local",
+ (chan->global_identifier), chan);
+ channel_mark_local(chan);
+ } else {
+ log_debug(LD_CHANNEL,
+ "Marking new incoming channel %"PRIu64 " at %p as remote",
+ (chan->global_identifier), chan);
+ channel_mark_remote(chan);
+ }
+
+ channel_mark_incoming(chan);
+
+ /* Register it */
+ channel_register(chan);
+
+ return chan;
+}
+
+/*********
+ * Casts *
+ ********/
+
+/**
+ * Cast a channel_tls_t to a channel_t.
+ */
+channel_t *
+channel_tls_to_base(channel_tls_t *tlschan)
+{
+ if (!tlschan) return NULL;
+
+ return &(tlschan->base_);
+}
+
+/**
+ * Cast a channel_t to a channel_tls_t, with appropriate type-checking
+ * asserts.
+ */
+channel_tls_t *
+channel_tls_from_base(channel_t *chan)
+{
+ if (!chan) return NULL;
+
+ tor_assert(chan->magic == TLS_CHAN_MAGIC);
+
+ return (channel_tls_t *)(chan);
+}
+
+/********************************************
+ * Method implementations for channel_tls_t *
+ *******************************************/
+
+/**
+ * Close a channel_tls_t.
+ *
+ * This implements the close method for channel_tls_t.
+ */
+static void
+channel_tls_close_method(channel_t *chan)
+{
+ channel_tls_t *tlschan = BASE_CHAN_TO_TLS(chan);
+
+ tor_assert(tlschan);
+
+ if (tlschan->conn) connection_or_close_normally(tlschan->conn, 1);
+ else {
+ /* Weird - we'll have to change the state ourselves, I guess */
+ log_info(LD_CHANNEL,
+ "Tried to close channel_tls_t %p with NULL conn",
+ tlschan);
+ channel_change_state(chan, CHANNEL_STATE_ERROR);
+ }
+}
+
+/**
+ * Describe the transport for a channel_tls_t.
+ *
+ * This returns the string "TLS channel on connection <id>" to the upper
+ * layer.
+ */
+static const char *
+channel_tls_describe_transport_method(channel_t *chan)
+{
+ static char *buf = NULL;
+ uint64_t id;
+ channel_tls_t *tlschan;
+ const char *rv = NULL;
+
+ tor_assert(chan);
+
+ tlschan = BASE_CHAN_TO_TLS(chan);
+
+ if (tlschan->conn) {
+ id = TO_CONN(tlschan->conn)->global_identifier;
+
+ if (buf) tor_free(buf);
+ tor_asprintf(&buf,
+ "TLS channel (connection %"PRIu64 ")",
+ (id));
+
+ rv = buf;
+ } else {
+ rv = "TLS channel (no connection)";
+ }
+
+ return rv;
+}
+
+/**
+ * Free a channel_tls_t.
+ *
+ * This is called by the generic channel layer when freeing a channel_tls_t;
+ * this happens either on a channel which has already reached
+ * CHANNEL_STATE_CLOSED or CHANNEL_STATE_ERROR from channel_run_cleanup() or
+ * on shutdown from channel_free_all(). In the latter case we might still
+ * have an orconn active (which connection_free_all() will get to later),
+ * so we should null out its channel pointer now.
+ */
+static void
+channel_tls_free_method(channel_t *chan)
+{
+ channel_tls_t *tlschan = BASE_CHAN_TO_TLS(chan);
+
+ tor_assert(tlschan);
+
+ if (tlschan->conn) {
+ tlschan->conn->chan = NULL;
+ tlschan->conn = NULL;
+ }
+}
+
+/**
+ * Get an estimate of the average TLS overhead for the upper layer.
+ */
+static double
+channel_tls_get_overhead_estimate_method(channel_t *chan)
+{
+ double overhead = 1.0;
+ channel_tls_t *tlschan = BASE_CHAN_TO_TLS(chan);
+
+ tor_assert(tlschan);
+ tor_assert(tlschan->conn);
+
+ /* Just return 1.0f if we don't have sensible data */
+ if (tlschan->conn->bytes_xmitted > 0 &&
+ tlschan->conn->bytes_xmitted_by_tls >=
+ tlschan->conn->bytes_xmitted) {
+ overhead = ((double)(tlschan->conn->bytes_xmitted_by_tls)) /
+ ((double)(tlschan->conn->bytes_xmitted));
+
+ /*
+ * Never estimate more than 2.0; otherwise we get silly large estimates
+ * at the very start of a new TLS connection.
+ */
+ if (overhead > 2.0)
+ overhead = 2.0;
+ }
+
+ log_debug(LD_CHANNEL,
+ "Estimated overhead ratio for TLS chan %"PRIu64 " is %f",
+ (chan->global_identifier), overhead);
+
+ return overhead;
+}
+
+/**
+ * Get the remote address of a channel_tls_t.
+ *
+ * This implements the get_remote_addr method for channel_tls_t; copy the
+ * remote endpoint of the channel to addr_out and return 1 (always
+ * succeeds for this transport).
+ */
+static int
+channel_tls_get_remote_addr_method(channel_t *chan, tor_addr_t *addr_out)
+{
+ int rv = 0;
+ channel_tls_t *tlschan = BASE_CHAN_TO_TLS(chan);
+
+ tor_assert(tlschan);
+ tor_assert(addr_out);
+
+ if (tlschan->conn) {
+ tor_addr_copy(addr_out, &(tlschan->conn->real_addr));
+ rv = 1;
+ } else tor_addr_make_unspec(addr_out);
+
+ return rv;
+}
+
+/**
+ * Get the name of the pluggable transport used by a channel_tls_t.
+ *
+ * This implements the get_transport_name for channel_tls_t. If the
+ * channel uses a pluggable transport, copy its name to
+ * <b>transport_out</b> and return 0. If the channel did not use a
+ * pluggable transport, return -1.
+ */
+static int
+channel_tls_get_transport_name_method(channel_t *chan, char **transport_out)
+{
+ channel_tls_t *tlschan = BASE_CHAN_TO_TLS(chan);
+
+ tor_assert(tlschan);
+ tor_assert(transport_out);
+ tor_assert(tlschan->conn);
+
+ if (!tlschan->conn->ext_or_transport)
+ return -1;
+
+ *transport_out = tor_strdup(tlschan->conn->ext_or_transport);
+ return 0;
+}
+
+/**
+ * Get endpoint description of a channel_tls_t.
+ *
+ * This implements the get_remote_descr method for channel_tls_t; it returns
+ * a text description of the remote endpoint of the channel suitable for use
+ * in log messages. The req parameter is 0 for the canonical address or 1 for
+ * the actual address seen.
+ */
+static const char *
+channel_tls_get_remote_descr_method(channel_t *chan, int flags)
+{
+#define MAX_DESCR_LEN 32
+
+ static char buf[MAX_DESCR_LEN + 1];
+ channel_tls_t *tlschan = BASE_CHAN_TO_TLS(chan);
+ connection_t *conn;
+ const char *answer = NULL;
+ char *addr_str;
+
+ tor_assert(tlschan);
+
+ if (tlschan->conn) {
+ conn = TO_CONN(tlschan->conn);
+ switch (flags) {
+ case 0:
+ /* Canonical address with port*/
+ tor_snprintf(buf, MAX_DESCR_LEN + 1,
+ "%s:%u", conn->address, conn->port);
+ answer = buf;
+ break;
+ case GRD_FLAG_ORIGINAL:
+ /* Actual address with port */
+ addr_str = tor_addr_to_str_dup(&(tlschan->conn->real_addr));
+ tor_snprintf(buf, MAX_DESCR_LEN + 1,
+ "%s:%u", addr_str, conn->port);
+ tor_free(addr_str);
+ answer = buf;
+ break;
+ case GRD_FLAG_ADDR_ONLY:
+ /* Canonical address, no port */
+ strlcpy(buf, conn->address, sizeof(buf));
+ answer = buf;
+ break;
+ case GRD_FLAG_ORIGINAL|GRD_FLAG_ADDR_ONLY:
+ /* Actual address, no port */
+ addr_str = tor_addr_to_str_dup(&(tlschan->conn->real_addr));
+ strlcpy(buf, addr_str, sizeof(buf));
+ tor_free(addr_str);
+ answer = buf;
+ break;
+ default:
+ /* Something's broken in channel.c */
+ tor_assert_nonfatal_unreached_once();
+ }
+ } else {
+ strlcpy(buf, "(No connection)", sizeof(buf));
+ answer = buf;
+ }
+
+ return answer;
+}
+
+/**
+ * Tell the upper layer if we have queued writes.
+ *
+ * This implements the has_queued_writes method for channel_tls t_; it returns
+ * 1 iff we have queued writes on the outbuf of the underlying or_connection_t.
+ */
+static int
+channel_tls_has_queued_writes_method(channel_t *chan)
+{
+ size_t outbuf_len;
+ channel_tls_t *tlschan = BASE_CHAN_TO_TLS(chan);
+
+ tor_assert(tlschan);
+ if (!(tlschan->conn)) {
+ log_info(LD_CHANNEL,
+ "something called has_queued_writes on a tlschan "
+ "(%p with ID %"PRIu64 " but no conn",
+ chan, (chan->global_identifier));
+ }
+
+ outbuf_len = (tlschan->conn != NULL) ?
+ connection_get_outbuf_len(TO_CONN(tlschan->conn)) :
+ 0;
+
+ return (outbuf_len > 0);
+}
+
+/**
+ * Tell the upper layer if we're canonical.
+ *
+ * This implements the is_canonical method for channel_tls_t; if req is zero,
+ * it returns whether this is a canonical channel, and if it is one it returns
+ * whether that can be relied upon.
+ */
+static int
+channel_tls_is_canonical_method(channel_t *chan, int req)
+{
+ int answer = 0;
+ channel_tls_t *tlschan = BASE_CHAN_TO_TLS(chan);
+
+ tor_assert(tlschan);
+
+ if (tlschan->conn) {
+ switch (req) {
+ case 0:
+ answer = tlschan->conn->is_canonical;
+ break;
+ case 1:
+ /*
+ * Is the is_canonical bit reliable? In protocols version 2 and up
+ * we get the canonical address from a NETINFO cell, but in older
+ * versions it might be based on an obsolete descriptor.
+ */
+ answer = (tlschan->conn->link_proto >= 2);
+ break;
+ default:
+ /* This shouldn't happen; channel.c is broken if it does */
+ tor_assert_nonfatal_unreached_once();
+ }
+ }
+ /* else return 0 for tlschan->conn == NULL */
+
+ return answer;
+}
+
+/**
+ * Check if we match an extend_info_t.
+ *
+ * This implements the matches_extend_info method for channel_tls_t; the upper
+ * layer wants to know if this channel matches an extend_info_t.
+ */
+static int
+channel_tls_matches_extend_info_method(channel_t *chan,
+ extend_info_t *extend_info)
+{
+ channel_tls_t *tlschan = BASE_CHAN_TO_TLS(chan);
+
+ tor_assert(tlschan);
+ tor_assert(extend_info);
+
+ /* Never match if we have no conn */
+ if (!(tlschan->conn)) {
+ log_info(LD_CHANNEL,
+ "something called matches_extend_info on a tlschan "
+ "(%p with ID %"PRIu64 " but no conn",
+ chan, (chan->global_identifier));
+ return 0;
+ }
+
+ return (tor_addr_eq(&(extend_info->addr),
+ &(TO_CONN(tlschan->conn)->addr)) &&
+ (extend_info->port == TO_CONN(tlschan->conn)->port));
+}
+
+/**
+ * Check if we match a target address; return true iff we do.
+ *
+ * This implements the matches_target method for channel_tls t_; the upper
+ * layer wants to know if this channel matches a target address when extending
+ * a circuit.
+ */
+static int
+channel_tls_matches_target_method(channel_t *chan,
+ const tor_addr_t *target)
+{
+ channel_tls_t *tlschan = BASE_CHAN_TO_TLS(chan);
+
+ tor_assert(tlschan);
+ tor_assert(target);
+
+ /* Never match if we have no conn */
+ if (!(tlschan->conn)) {
+ log_info(LD_CHANNEL,
+ "something called matches_target on a tlschan "
+ "(%p with ID %"PRIu64 " but no conn",
+ chan, (chan->global_identifier));
+ return 0;
+ }
+
+ /* real_addr is the address this connection came from.
+ * base_.addr is updated by connection_or_init_conn_from_address()
+ * to be the address in the descriptor. It may be tempting to
+ * allow either address to be allowed, but if we did so, it would
+ * enable someone who steals a relay's keys to impersonate/MITM it
+ * from anywhere on the Internet! (Because they could make long-lived
+ * TLS connections from anywhere to all relays, and wait for them to
+ * be used for extends).
+ */
+ return tor_addr_eq(&(tlschan->conn->real_addr), target);
+}
+
+/**
+ * Tell the upper layer how many bytes we have queued and not yet
+ * sent.
+ */
+static size_t
+channel_tls_num_bytes_queued_method(channel_t *chan)
+{
+ channel_tls_t *tlschan = BASE_CHAN_TO_TLS(chan);
+
+ tor_assert(tlschan);
+ tor_assert(tlschan->conn);
+
+ return connection_get_outbuf_len(TO_CONN(tlschan->conn));
+}
+
+/**
+ * Tell the upper layer how many cells we can accept to write.
+ *
+ * This implements the num_cells_writeable method for channel_tls_t; it
+ * returns an estimate of the number of cells we can accept with
+ * channel_tls_write_*_cell().
+ */
+static int
+channel_tls_num_cells_writeable_method(channel_t *chan)
+{
+ size_t outbuf_len;
+ ssize_t n;
+ channel_tls_t *tlschan = BASE_CHAN_TO_TLS(chan);
+ size_t cell_network_size;
+
+ tor_assert(tlschan);
+ tor_assert(tlschan->conn);
+
+ cell_network_size = get_cell_network_size(tlschan->conn->wide_circ_ids);
+ outbuf_len = connection_get_outbuf_len(TO_CONN(tlschan->conn));
+ /* Get the number of cells */
+ n = CEIL_DIV(OR_CONN_HIGHWATER - outbuf_len, cell_network_size);
+ if (n < 0) n = 0;
+#if SIZEOF_SIZE_T > SIZEOF_INT
+ if (n > INT_MAX) n = INT_MAX;
+#endif
+
+ return (int)n;
+}
+
+/**
+ * Write a cell to a channel_tls_t.
+ *
+ * This implements the write_cell method for channel_tls_t; given a
+ * channel_tls_t and a cell_t, transmit the cell_t.
+ */
+static int
+channel_tls_write_cell_method(channel_t *chan, cell_t *cell)
+{
+ channel_tls_t *tlschan = BASE_CHAN_TO_TLS(chan);
+ int written = 0;
+
+ tor_assert(tlschan);
+ tor_assert(cell);
+
+ if (tlschan->conn) {
+ connection_or_write_cell_to_buf(cell, tlschan->conn);
+ ++written;
+ } else {
+ log_info(LD_CHANNEL,
+ "something called write_cell on a tlschan "
+ "(%p with ID %"PRIu64 " but no conn",
+ chan, (chan->global_identifier));
+ }
+
+ return written;
+}
+
+/**
+ * Write a packed cell to a channel_tls_t.
+ *
+ * This implements the write_packed_cell method for channel_tls_t; given a
+ * channel_tls_t and a packed_cell_t, transmit the packed_cell_t.
+ *
+ * Return 0 on success or negative value on error. The caller must free the
+ * packed cell.
+ */
+static int
+channel_tls_write_packed_cell_method(channel_t *chan,
+ packed_cell_t *packed_cell)
+{
+ tor_assert(chan);
+ channel_tls_t *tlschan = BASE_CHAN_TO_TLS(chan);
+ size_t cell_network_size = get_cell_network_size(chan->wide_circ_ids);
+
+ tor_assert(tlschan);
+ tor_assert(packed_cell);
+
+ if (tlschan->conn) {
+ connection_buf_add(packed_cell->body, cell_network_size,
+ TO_CONN(tlschan->conn));
+ } else {
+ log_info(LD_CHANNEL,
+ "something called write_packed_cell on a tlschan "
+ "(%p with ID %"PRIu64 " but no conn",
+ chan, (chan->global_identifier));
+ return -1;
+ }
+
+ return 0;
+}
+
+/**
+ * Write a variable-length cell to a channel_tls_t.
+ *
+ * This implements the write_var_cell method for channel_tls_t; given a
+ * channel_tls_t and a var_cell_t, transmit the var_cell_t.
+ */
+static int
+channel_tls_write_var_cell_method(channel_t *chan, var_cell_t *var_cell)
+{
+ channel_tls_t *tlschan = BASE_CHAN_TO_TLS(chan);
+ int written = 0;
+
+ tor_assert(tlschan);
+ tor_assert(var_cell);
+
+ if (tlschan->conn) {
+ connection_or_write_var_cell_to_buf(var_cell, tlschan->conn);
+ ++written;
+ } else {
+ log_info(LD_CHANNEL,
+ "something called write_var_cell on a tlschan "
+ "(%p with ID %"PRIu64 " but no conn",
+ chan, (chan->global_identifier));
+ }
+
+ return written;
+}
+
+/*************************************************
+ * Method implementations for channel_listener_t *
+ ************************************************/
+
+/**
+ * Close a channel_listener_t.
+ *
+ * This implements the close method for channel_listener_t.
+ */
+static void
+channel_tls_listener_close_method(channel_listener_t *chan_l)
+{
+ tor_assert(chan_l);
+
+ /*
+ * Listeners we just go ahead and change state through to CLOSED, but
+ * make sure to check if they're channel_tls_listener to NULL it out.
+ */
+ if (chan_l == channel_tls_listener)
+ channel_tls_listener = NULL;
+
+ if (!(chan_l->state == CHANNEL_LISTENER_STATE_CLOSING ||
+ chan_l->state == CHANNEL_LISTENER_STATE_CLOSED ||
+ chan_l->state == CHANNEL_LISTENER_STATE_ERROR)) {
+ channel_listener_change_state(chan_l, CHANNEL_LISTENER_STATE_CLOSING);
+ }
+
+ if (chan_l->incoming_list) {
+ SMARTLIST_FOREACH_BEGIN(chan_l->incoming_list,
+ channel_t *, ichan) {
+ channel_mark_for_close(ichan);
+ } SMARTLIST_FOREACH_END(ichan);
+
+ smartlist_free(chan_l->incoming_list);
+ chan_l->incoming_list = NULL;
+ }
+
+ if (!(chan_l->state == CHANNEL_LISTENER_STATE_CLOSED ||
+ chan_l->state == CHANNEL_LISTENER_STATE_ERROR)) {
+ channel_listener_change_state(chan_l, CHANNEL_LISTENER_STATE_CLOSED);
+ }
+}
+
+/**
+ * Describe the transport for a channel_listener_t.
+ *
+ * This returns the string "TLS channel (listening)" to the upper
+ * layer.
+ */
+static const char *
+channel_tls_listener_describe_transport_method(channel_listener_t *chan_l)
+{
+ tor_assert(chan_l);
+
+ return "TLS channel (listening)";
+}
+
+/*******************************************************
+ * Functions for handling events on an or_connection_t *
+ ******************************************************/
+
+/**
+ * Handle an orconn state change.
+ *
+ * This function will be called by connection_or.c when the or_connection_t
+ * associated with this channel_tls_t changes state.
+ */
+void
+channel_tls_handle_state_change_on_orconn(channel_tls_t *chan,
+ or_connection_t *conn,
+ uint8_t old_state,
+ uint8_t state)
+{
+ channel_t *base_chan;
+
+ tor_assert(chan);
+ tor_assert(conn);
+ tor_assert(conn->chan == chan);
+ tor_assert(chan->conn == conn);
+ /* Shut the compiler up without triggering -Wtautological-compare */
+ (void)old_state;
+
+ base_chan = TLS_CHAN_TO_BASE(chan);
+
+ /* Make sure the base connection state makes sense - shouldn't be error
+ * or closed. */
+
+ tor_assert(CHANNEL_IS_OPENING(base_chan) ||
+ CHANNEL_IS_OPEN(base_chan) ||
+ CHANNEL_IS_MAINT(base_chan) ||
+ CHANNEL_IS_CLOSING(base_chan));
+
+ /* Did we just go to state open? */
+ if (state == OR_CONN_STATE_OPEN) {
+ /*
+ * We can go to CHANNEL_STATE_OPEN from CHANNEL_STATE_OPENING or
+ * CHANNEL_STATE_MAINT on this.
+ */
+ channel_change_state_open(base_chan);
+ /* We might have just become writeable; check and tell the scheduler */
+ if (connection_or_num_cells_writeable(conn) > 0) {
+ scheduler_channel_wants_writes(base_chan);
+ }
+ } else {
+ /*
+ * Not open, so from CHANNEL_STATE_OPEN we go to CHANNEL_STATE_MAINT,
+ * otherwise no change.
+ */
+ if (CHANNEL_IS_OPEN(base_chan)) {
+ channel_change_state(base_chan, CHANNEL_STATE_MAINT);
+ }
+ }
+}
+
+#ifdef KEEP_TIMING_STATS
+
+/**
+ * Timing states wrapper.
+ *
+ * This is a wrapper function around the actual function that processes the
+ * <b>cell</b> that just arrived on <b>chan</b>. Increment <b>*time</b>
+ * by the number of microseconds used by the call to <b>*func(cell, chan)</b>.
+ */
+static void
+channel_tls_time_process_cell(cell_t *cell, channel_tls_t *chan, int *time,
+ void (*func)(cell_t *, channel_tls_t *))
+{
+ struct timeval start, end;
+ long time_passed;
+
+ tor_gettimeofday(&start);
+
+ (*func)(cell, chan);
+
+ tor_gettimeofday(&end);
+ time_passed = tv_udiff(&start, &end) ;
+
+ if (time_passed > 10000) { /* more than 10ms */
+ log_debug(LD_OR,"That call just took %ld ms.",time_passed/1000);
+ }
+
+ if (time_passed < 0) {
+ log_info(LD_GENERAL,"That call took us back in time!");
+ time_passed = 0;
+ }
+
+ *time += time_passed;
+}
+#endif /* defined(KEEP_TIMING_STATS) */
+
+/**
+ * Handle an incoming cell on a channel_tls_t.
+ *
+ * This is called from connection_or.c to handle an arriving cell; it checks
+ * for cell types specific to the handshake for this transport protocol and
+ * handles them, and queues all other cells to the channel_t layer, which
+ * eventually will hand them off to command.c.
+ *
+ * The channel layer itself decides whether the cell should be queued or
+ * can be handed off immediately to the upper-layer code. It is responsible
+ * for copying in the case that it queues; we merely pass pointers through
+ * which we get from connection_or_process_cells_from_inbuf().
+ */
+void
+channel_tls_handle_cell(cell_t *cell, or_connection_t *conn)
+{
+ channel_tls_t *chan;
+ int handshaking;
+
+#ifdef KEEP_TIMING_STATS
+#define PROCESS_CELL(tp, cl, cn) STMT_BEGIN { \
+ ++num ## tp; \
+ channel_tls_time_process_cell(cl, cn, & tp ## time , \
+ channel_tls_process_ ## tp ## _cell); \
+ } STMT_END
+#else /* !(defined(KEEP_TIMING_STATS)) */
+#define PROCESS_CELL(tp, cl, cn) channel_tls_process_ ## tp ## _cell(cl, cn)
+#endif /* defined(KEEP_TIMING_STATS) */
+
+ tor_assert(cell);
+ tor_assert(conn);
+
+ chan = conn->chan;
+
+ if (!chan) {
+ log_warn(LD_CHANNEL,
+ "Got a cell_t on an OR connection with no channel");
+ return;
+ }
+
+ handshaking = (TO_CONN(conn)->state != OR_CONN_STATE_OPEN);
+
+ if (conn->base_.marked_for_close)
+ return;
+
+ /* Reject all but VERSIONS and NETINFO when handshaking. */
+ /* (VERSIONS should actually be impossible; it's variable-length.) */
+ if (handshaking && cell->command != CELL_VERSIONS &&
+ cell->command != CELL_NETINFO) {
+ log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
+ "Received unexpected cell command %d in chan state %s / "
+ "conn state %s; closing the connection.",
+ (int)cell->command,
+ channel_state_to_string(TLS_CHAN_TO_BASE(chan)->state),
+ conn_state_to_string(CONN_TYPE_OR, TO_CONN(conn)->state));
+ connection_or_close_for_error(conn, 0);
+ return;
+ }
+
+ if (conn->base_.state == OR_CONN_STATE_OR_HANDSHAKING_V3)
+ or_handshake_state_record_cell(conn, conn->handshake_state, cell, 1);
+
+ /* We note that we're on the internet whenever we read a cell. This is
+ * a fast operation. */
+ entry_guards_note_internet_connectivity(get_guard_selection_info());
+ rep_hist_padding_count_read(PADDING_TYPE_TOTAL);
+
+ if (TLS_CHAN_TO_BASE(chan)->currently_padding)
+ rep_hist_padding_count_read(PADDING_TYPE_ENABLED_TOTAL);
+
+ switch (cell->command) {
+ case CELL_PADDING:
+ rep_hist_padding_count_read(PADDING_TYPE_CELL);
+ if (TLS_CHAN_TO_BASE(chan)->currently_padding)
+ rep_hist_padding_count_read(PADDING_TYPE_ENABLED_CELL);
+ ++stats_n_padding_cells_processed;
+ /* do nothing */
+ break;
+ case CELL_VERSIONS:
+ tor_fragile_assert();
+ break;
+ case CELL_NETINFO:
+ ++stats_n_netinfo_cells_processed;
+ PROCESS_CELL(netinfo, cell, chan);
+ break;
+ case CELL_PADDING_NEGOTIATE:
+ ++stats_n_netinfo_cells_processed;
+ PROCESS_CELL(padding_negotiate, cell, chan);
+ break;
+ case CELL_CREATE:
+ case CELL_CREATE_FAST:
+ case CELL_CREATED:
+ case CELL_CREATED_FAST:
+ case CELL_RELAY:
+ case CELL_RELAY_EARLY:
+ case CELL_DESTROY:
+ case CELL_CREATE2:
+ case CELL_CREATED2:
+ /*
+ * These are all transport independent and we pass them up through the
+ * channel_t mechanism. They are ultimately handled in command.c.
+ */
+ channel_process_cell(TLS_CHAN_TO_BASE(chan), cell);
+ break;
+ default:
+ log_fn(LOG_INFO, LD_PROTOCOL,
+ "Cell of unknown type (%d) received in channeltls.c. "
+ "Dropping.",
+ cell->command);
+ break;
+ }
+}
+
+/**
+ * Handle an incoming variable-length cell on a channel_tls_t.
+ *
+ * Process a <b>var_cell</b> that was just received on <b>conn</b>. Keep
+ * internal statistics about how many of each cell we've processed so far
+ * this second, and the total number of microseconds it took to
+ * process each type of cell. All the var_cell commands are handshake-
+ * related and live below the channel_t layer, so no variable-length
+ * cells ever get delivered in the current implementation, but I've left
+ * the mechanism in place for future use.
+ *
+ * If we were handing them off to the upper layer, the channel_t queueing
+ * code would be responsible for memory management, and we'd just be passing
+ * pointers through from connection_or_process_cells_from_inbuf(). That
+ * caller always frees them after this function returns, so this function
+ * should never free var_cell.
+ */
+void
+channel_tls_handle_var_cell(var_cell_t *var_cell, or_connection_t *conn)
+{
+ channel_tls_t *chan;
+
+#ifdef KEEP_TIMING_STATS
+ /* how many of each cell have we seen so far this second? needs better
+ * name. */
+ static int num_versions = 0, num_certs = 0;
+ static time_t current_second = 0; /* from previous calls to time */
+ time_t now = time(NULL);
+
+ if (current_second == 0) current_second = now;
+ if (now > current_second) { /* the second has rolled over */
+ /* print stats */
+ log_info(LD_OR,
+ "At end of second: %d versions (%d ms), %d certs (%d ms)",
+ num_versions, versions_time / ((now - current_second) * 1000),
+ num_certs, certs_time / ((now - current_second) * 1000));
+
+ num_versions = num_certs = 0;
+ versions_time = certs_time = 0;
+
+ /* remember which second it is, for next time */
+ current_second = now;
+ }
+#endif /* defined(KEEP_TIMING_STATS) */
+
+ tor_assert(var_cell);
+ tor_assert(conn);
+
+ chan = conn->chan;
+
+ if (!chan) {
+ log_warn(LD_CHANNEL,
+ "Got a var_cell_t on an OR connection with no channel");
+ return;
+ }
+
+ if (TO_CONN(conn)->marked_for_close)
+ return;
+
+ switch (TO_CONN(conn)->state) {
+ case OR_CONN_STATE_OR_HANDSHAKING_V2:
+ if (var_cell->command != CELL_VERSIONS) {
+ log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
+ "Received a cell with command %d in unexpected "
+ "orconn state \"%s\" [%d], channel state \"%s\" [%d]; "
+ "closing the connection.",
+ (int)(var_cell->command),
+ conn_state_to_string(CONN_TYPE_OR, TO_CONN(conn)->state),
+ TO_CONN(conn)->state,
+ channel_state_to_string(TLS_CHAN_TO_BASE(chan)->state),
+ (int)(TLS_CHAN_TO_BASE(chan)->state));
+ /*
+ * The code in connection_or.c will tell channel_t to close for
+ * error; it will go to CHANNEL_STATE_CLOSING, and then to
+ * CHANNEL_STATE_ERROR when conn is closed.
+ */
+ connection_or_close_for_error(conn, 0);
+ return;
+ }
+ break;
+ case OR_CONN_STATE_TLS_HANDSHAKING:
+ /* If we're using bufferevents, it's entirely possible for us to
+ * notice "hey, data arrived!" before we notice "hey, the handshake
+ * finished!" And we need to be accepting both at once to handle both
+ * the v2 and v3 handshakes. */
+ /* But that should be happening any longer've disabled bufferevents. */
+ tor_assert_nonfatal_unreached_once();
+
+ /* fall through */
+ case OR_CONN_STATE_TLS_SERVER_RENEGOTIATING:
+ if (!(command_allowed_before_handshake(var_cell->command))) {
+ log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
+ "Received a cell with command %d in unexpected "
+ "orconn state \"%s\" [%d], channel state \"%s\" [%d]; "
+ "closing the connection.",
+ (int)(var_cell->command),
+ conn_state_to_string(CONN_TYPE_OR, TO_CONN(conn)->state),
+ (int)(TO_CONN(conn)->state),
+ channel_state_to_string(TLS_CHAN_TO_BASE(chan)->state),
+ (int)(TLS_CHAN_TO_BASE(chan)->state));
+ /* see above comment about CHANNEL_STATE_ERROR */
+ connection_or_close_for_error(conn, 0);
+ return;
+ } else {
+ if (enter_v3_handshake_with_cell(var_cell, chan) < 0)
+ return;
+ }
+ break;
+ case OR_CONN_STATE_OR_HANDSHAKING_V3:
+ if (var_cell->command != CELL_AUTHENTICATE)
+ or_handshake_state_record_var_cell(conn, conn->handshake_state,
+ var_cell, 1);
+ break; /* Everything is allowed */
+ case OR_CONN_STATE_OPEN:
+ if (conn->link_proto < 3) {
+ log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
+ "Received a variable-length cell with command %d in orconn "
+ "state %s [%d], channel state %s [%d] with link protocol %d; "
+ "ignoring it.",
+ (int)(var_cell->command),
+ conn_state_to_string(CONN_TYPE_OR, TO_CONN(conn)->state),
+ (int)(TO_CONN(conn)->state),
+ channel_state_to_string(TLS_CHAN_TO_BASE(chan)->state),
+ (int)(TLS_CHAN_TO_BASE(chan)->state),
+ (int)(conn->link_proto));
+ return;
+ }
+ break;
+ default:
+ log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
+ "Received var-length cell with command %d in unexpected "
+ "orconn state \"%s\" [%d], channel state \"%s\" [%d]; "
+ "ignoring it.",
+ (int)(var_cell->command),
+ conn_state_to_string(CONN_TYPE_OR, TO_CONN(conn)->state),
+ (int)(TO_CONN(conn)->state),
+ channel_state_to_string(TLS_CHAN_TO_BASE(chan)->state),
+ (int)(TLS_CHAN_TO_BASE(chan)->state));
+ return;
+ }
+
+ /* We note that we're on the internet whenever we read a cell. This is
+ * a fast operation. */
+ entry_guards_note_internet_connectivity(get_guard_selection_info());
+
+ /* Now handle the cell */
+
+ switch (var_cell->command) {
+ case CELL_VERSIONS:
+ ++stats_n_versions_cells_processed;
+ PROCESS_CELL(versions, var_cell, chan);
+ break;
+ case CELL_VPADDING:
+ ++stats_n_vpadding_cells_processed;
+ /* Do nothing */
+ break;
+ case CELL_CERTS:
+ ++stats_n_certs_cells_processed;
+ PROCESS_CELL(certs, var_cell, chan);
+ break;
+ case CELL_AUTH_CHALLENGE:
+ ++stats_n_auth_challenge_cells_processed;
+ PROCESS_CELL(auth_challenge, var_cell, chan);
+ break;
+ case CELL_AUTHENTICATE:
+ ++stats_n_authenticate_cells_processed;
+ PROCESS_CELL(authenticate, var_cell, chan);
+ break;
+ case CELL_AUTHORIZE:
+ ++stats_n_authorize_cells_processed;
+ /* Ignored so far. */
+ break;
+ default:
+ log_fn(LOG_INFO, LD_PROTOCOL,
+ "Variable-length cell of unknown type (%d) received.",
+ (int)(var_cell->command));
+ break;
+ }
+}
+
+/**
+ * Update channel marks after connection_or.c has changed an address.
+ *
+ * This is called from connection_or_init_conn_from_address() after the
+ * connection's _base.addr or real_addr fields have potentially been changed
+ * so we can recalculate the local mark. Notably, this happens when incoming
+ * connections are reverse-proxied and we only learn the real address of the
+ * remote router by looking it up in the consensus after we finish the
+ * handshake and know an authenticated identity digest.
+ */
+void
+channel_tls_update_marks(or_connection_t *conn)
+{
+ channel_t *chan = NULL;
+
+ tor_assert(conn);
+ tor_assert(conn->chan);
+
+ chan = TLS_CHAN_TO_BASE(conn->chan);
+
+ if (is_local_addr(&(TO_CONN(conn)->addr))) {
+ if (!channel_is_local(chan)) {
+ log_debug(LD_CHANNEL,
+ "Marking channel %"PRIu64 " at %p as local",
+ (chan->global_identifier), chan);
+ channel_mark_local(chan);
+ }
+ } else {
+ if (channel_is_local(chan)) {
+ log_debug(LD_CHANNEL,
+ "Marking channel %"PRIu64 " at %p as remote",
+ (chan->global_identifier), chan);
+ channel_mark_remote(chan);
+ }
+ }
+}
+
+/**
+ * Check if this cell type is allowed before the handshake is finished.
+ *
+ * Return true if <b>command</b> is a cell command that's allowed to start a
+ * V3 handshake.
+ */
+static int
+command_allowed_before_handshake(uint8_t command)
+{
+ switch (command) {
+ case CELL_VERSIONS:
+ case CELL_VPADDING:
+ case CELL_AUTHORIZE:
+ return 1;
+ default:
+ return 0;
+ }
+}
+
+/**
+ * Start a V3 handshake on an incoming connection.
+ *
+ * Called when we as a server receive an appropriate cell while waiting
+ * either for a cell or a TLS handshake. Set the connection's state to
+ * "handshaking_v3', initializes the or_handshake_state field as needed,
+ * and add the cell to the hash of incoming cells.)
+ */
+static int
+enter_v3_handshake_with_cell(var_cell_t *cell, channel_tls_t *chan)
+{
+ int started_here = 0;
+
+ tor_assert(cell);
+ tor_assert(chan);
+ tor_assert(chan->conn);
+
+ started_here = connection_or_nonopen_was_started_here(chan->conn);
+
+ tor_assert(TO_CONN(chan->conn)->state == OR_CONN_STATE_TLS_HANDSHAKING ||
+ TO_CONN(chan->conn)->state ==
+ OR_CONN_STATE_TLS_SERVER_RENEGOTIATING);
+
+ if (started_here) {
+ log_fn(LOG_PROTOCOL_WARN, LD_OR,
+ "Received a cell while TLS-handshaking, not in "
+ "OR_HANDSHAKING_V3, on a connection we originated.");
+ }
+ connection_or_block_renegotiation(chan->conn);
+ chan->conn->base_.state = OR_CONN_STATE_OR_HANDSHAKING_V3;
+ if (connection_init_or_handshake_state(chan->conn, started_here) < 0) {
+ connection_or_close_for_error(chan->conn, 0);
+ return -1;
+ }
+ or_handshake_state_record_var_cell(chan->conn,
+ chan->conn->handshake_state, cell, 1);
+ return 0;
+}
+
+/**
+ * Process a 'versions' cell.
+ *
+ * This function is called to handle an incoming VERSIONS cell; the current
+ * link protocol version must be 0 to indicate that no version has yet been
+ * negotiated. We compare the versions in the cell to the list of versions
+ * we support, pick the highest version we have in common, and continue the
+ * negotiation from there.
+ */
+static void
+channel_tls_process_versions_cell(var_cell_t *cell, channel_tls_t *chan)
+{
+ int highest_supported_version = 0;
+ int started_here = 0;
+
+ tor_assert(cell);
+ tor_assert(chan);
+ tor_assert(chan->conn);
+
+ if ((cell->payload_len % 2) == 1) {
+ log_fn(LOG_PROTOCOL_WARN, LD_OR,
+ "Received a VERSION cell with odd payload length %d; "
+ "closing connection.",cell->payload_len);
+ connection_or_close_for_error(chan->conn, 0);
+ return;
+ }
+
+ started_here = connection_or_nonopen_was_started_here(chan->conn);
+
+ if (chan->conn->link_proto != 0 ||
+ (chan->conn->handshake_state &&
+ chan->conn->handshake_state->received_versions)) {
+ log_fn(LOG_PROTOCOL_WARN, LD_OR,
+ "Received a VERSIONS cell on a connection with its version "
+ "already set to %d; dropping",
+ (int)(chan->conn->link_proto));
+ return;
+ }
+ switch (chan->conn->base_.state)
+ {
+ case OR_CONN_STATE_OR_HANDSHAKING_V2:
+ case OR_CONN_STATE_OR_HANDSHAKING_V3:
+ break;
+ case OR_CONN_STATE_TLS_HANDSHAKING:
+ case OR_CONN_STATE_TLS_SERVER_RENEGOTIATING:
+ default:
+ log_fn(LOG_PROTOCOL_WARN, LD_OR,
+ "VERSIONS cell while in unexpected state");
+ return;
+ }
+
+ tor_assert(chan->conn->handshake_state);
+
+ {
+ int i;
+ const uint8_t *cp = cell->payload;
+ for (i = 0; i < cell->payload_len / 2; ++i, cp += 2) {
+ uint16_t v = ntohs(get_uint16(cp));
+ if (is_or_protocol_version_known(v) && v > highest_supported_version)
+ highest_supported_version = v;
+ }
+ }
+ if (!highest_supported_version) {
+ log_fn(LOG_PROTOCOL_WARN, LD_OR,
+ "Couldn't find a version in common between my version list and the "
+ "list in the VERSIONS cell; closing connection.");
+ connection_or_close_for_error(chan->conn, 0);
+ return;
+ } else if (highest_supported_version == 1) {
+ /* Negotiating version 1 makes no sense, since version 1 has no VERSIONS
+ * cells. */
+ log_fn(LOG_PROTOCOL_WARN, LD_OR,
+ "Used version negotiation protocol to negotiate a v1 connection. "
+ "That's crazily non-compliant. Closing connection.");
+ connection_or_close_for_error(chan->conn, 0);
+ return;
+ } else if (highest_supported_version < 3 &&
+ chan->conn->base_.state == OR_CONN_STATE_OR_HANDSHAKING_V3) {
+ log_fn(LOG_PROTOCOL_WARN, LD_OR,
+ "Negotiated link protocol 2 or lower after doing a v3 TLS "
+ "handshake. Closing connection.");
+ connection_or_close_for_error(chan->conn, 0);
+ return;
+ } else if (highest_supported_version != 2 &&
+ chan->conn->base_.state == OR_CONN_STATE_OR_HANDSHAKING_V2) {
+ /* XXXX This should eventually be a log_protocol_warn */
+ log_fn(LOG_WARN, LD_OR,
+ "Negotiated link with non-2 protocol after doing a v2 TLS "
+ "handshake with %s. Closing connection.",
+ fmt_addr(&chan->conn->base_.addr));
+ connection_or_close_for_error(chan->conn, 0);
+ return;
+ }
+
+ rep_hist_note_negotiated_link_proto(highest_supported_version, started_here);
+
+ chan->conn->link_proto = highest_supported_version;
+ chan->conn->handshake_state->received_versions = 1;
+
+ if (chan->conn->link_proto == 2) {
+ log_info(LD_OR,
+ "Negotiated version %d with %s:%d; sending NETINFO.",
+ highest_supported_version,
+ safe_str_client(chan->conn->base_.address),
+ chan->conn->base_.port);
+
+ if (connection_or_send_netinfo(chan->conn) < 0) {
+ connection_or_close_for_error(chan->conn, 0);
+ return;
+ }
+ } else {
+ const int send_versions = !started_here;
+ /* If we want to authenticate, send a CERTS cell */
+ const int send_certs = !started_here || public_server_mode(get_options());
+ /* If we're a host that got a connection, ask for authentication. */
+ const int send_chall = !started_here;
+ /* If our certs cell will authenticate us, we can send a netinfo cell
+ * right now. */
+ const int send_netinfo = !started_here;
+ const int send_any =
+ send_versions || send_certs || send_chall || send_netinfo;
+ tor_assert(chan->conn->link_proto >= 3);
+
+ log_info(LD_OR,
+ "Negotiated version %d with %s:%d; %s%s%s%s%s",
+ highest_supported_version,
+ safe_str_client(chan->conn->base_.address),
+ chan->conn->base_.port,
+ send_any ? "Sending cells:" : "Waiting for CERTS cell",
+ send_versions ? " VERSIONS" : "",
+ send_certs ? " CERTS" : "",
+ send_chall ? " AUTH_CHALLENGE" : "",
+ send_netinfo ? " NETINFO" : "");
+
+#ifdef DISABLE_V3_LINKPROTO_SERVERSIDE
+ if (1) {
+ connection_or_close_normally(chan->conn, 1);
+ return;
+ }
+#endif /* defined(DISABLE_V3_LINKPROTO_SERVERSIDE) */
+
+ if (send_versions) {
+ if (connection_or_send_versions(chan->conn, 1) < 0) {
+ log_warn(LD_OR, "Couldn't send versions cell");
+ connection_or_close_for_error(chan->conn, 0);
+ return;
+ }
+ }
+
+ /* We set this after sending the versions cell. */
+ /*XXXXX symbolic const.*/
+ TLS_CHAN_TO_BASE(chan)->wide_circ_ids =
+ chan->conn->link_proto >= MIN_LINK_PROTO_FOR_WIDE_CIRC_IDS;
+ chan->conn->wide_circ_ids = TLS_CHAN_TO_BASE(chan)->wide_circ_ids;
+
+ TLS_CHAN_TO_BASE(chan)->padding_enabled =
+ chan->conn->link_proto >= MIN_LINK_PROTO_FOR_CHANNEL_PADDING;
+
+ if (send_certs) {
+ if (connection_or_send_certs_cell(chan->conn) < 0) {
+ log_warn(LD_OR, "Couldn't send certs cell");
+ connection_or_close_for_error(chan->conn, 0);
+ return;
+ }
+ }
+ if (send_chall) {
+ if (connection_or_send_auth_challenge_cell(chan->conn) < 0) {
+ log_warn(LD_OR, "Couldn't send auth_challenge cell");
+ connection_or_close_for_error(chan->conn, 0);
+ return;
+ }
+ }
+ if (send_netinfo) {
+ if (connection_or_send_netinfo(chan->conn) < 0) {
+ log_warn(LD_OR, "Couldn't send netinfo cell");
+ connection_or_close_for_error(chan->conn, 0);
+ return;
+ }
+ }
+ }
+}
+
+/**
+ * Process a 'padding_negotiate' cell.
+ *
+ * This function is called to handle an incoming PADDING_NEGOTIATE cell;
+ * enable or disable padding accordingly, and read and act on its timeout
+ * value contents.
+ */
+static void
+channel_tls_process_padding_negotiate_cell(cell_t *cell, channel_tls_t *chan)
+{
+ channelpadding_negotiate_t *negotiation;
+ tor_assert(cell);
+ tor_assert(chan);
+ tor_assert(chan->conn);
+
+ if (chan->conn->link_proto < MIN_LINK_PROTO_FOR_CHANNEL_PADDING) {
+ log_fn(LOG_PROTOCOL_WARN, LD_OR,
+ "Received a PADDING_NEGOTIATE cell on v%d connection; dropping.",
+ chan->conn->link_proto);
+ return;
+ }
+
+ if (channelpadding_negotiate_parse(&negotiation, cell->payload,
+ CELL_PAYLOAD_SIZE) < 0) {
+ log_fn(LOG_PROTOCOL_WARN, LD_OR,
+ "Received malformed PADDING_NEGOTIATE cell on v%d connection; "
+ "dropping.", chan->conn->link_proto);
+
+ return;
+ }
+
+ channelpadding_update_padding_for_channel(TLS_CHAN_TO_BASE(chan),
+ negotiation);
+
+ channelpadding_negotiate_free(negotiation);
+}
+
+/**
- * Process a 'netinfo' cell.
++ * Helper: compute the absolute value of a time_t.
++ *
++ * (we need this because labs() doesn't always work for time_t, since
++ * long can be shorter than time_t.)
++ */
++static inline time_t
++time_abs(time_t val)
++{
++ return (val < 0) ? -val : val;
++}
++
++/**
++ * Process a 'netinfo' cell
+ *
+ * This function is called to handle an incoming NETINFO cell; read and act
+ * on its contents, and set the connection state to "open".
+ */
+static void
+channel_tls_process_netinfo_cell(cell_t *cell, channel_tls_t *chan)
+{
+ time_t timestamp;
+ uint8_t my_addr_type;
+ uint8_t my_addr_len;
+ const uint8_t *my_addr_ptr;
+ const uint8_t *cp, *end;
+ uint8_t n_other_addrs;
+ time_t now = time(NULL);
+ const routerinfo_t *me = router_get_my_routerinfo();
+
- long apparent_skew = 0;
++ time_t apparent_skew = 0;
+ tor_addr_t my_apparent_addr = TOR_ADDR_NULL;
+ int started_here = 0;
+ const char *identity_digest = NULL;
+
+ tor_assert(cell);
+ tor_assert(chan);
+ tor_assert(chan->conn);
+
+ if (chan->conn->link_proto < 2) {
+ log_fn(LOG_PROTOCOL_WARN, LD_OR,
+ "Received a NETINFO cell on %s connection; dropping.",
+ chan->conn->link_proto == 0 ? "non-versioned" : "a v1");
+ return;
+ }
+ if (chan->conn->base_.state != OR_CONN_STATE_OR_HANDSHAKING_V2 &&
+ chan->conn->base_.state != OR_CONN_STATE_OR_HANDSHAKING_V3) {
+ log_fn(LOG_PROTOCOL_WARN, LD_OR,
+ "Received a NETINFO cell on non-handshaking connection; dropping.");
+ return;
+ }
+ tor_assert(chan->conn->handshake_state &&
+ chan->conn->handshake_state->received_versions);
+ started_here = connection_or_nonopen_was_started_here(chan->conn);
+ identity_digest = chan->conn->identity_digest;
+
+ if (chan->conn->base_.state == OR_CONN_STATE_OR_HANDSHAKING_V3) {
+ tor_assert(chan->conn->link_proto >= 3);
+ if (started_here) {
+ if (!(chan->conn->handshake_state->authenticated)) {
+ log_fn(LOG_PROTOCOL_WARN, LD_OR,
+ "Got a NETINFO cell from server, "
+ "but no authentication. Closing the connection.");
+ connection_or_close_for_error(chan->conn, 0);
+ return;
+ }
+ } else {
+ /* we're the server. If the client never authenticated, we have
+ some housekeeping to do.*/
+ if (!(chan->conn->handshake_state->authenticated)) {
+ tor_assert(tor_digest_is_zero(
+ (const char*)(chan->conn->handshake_state->
+ authenticated_rsa_peer_id)));
+ tor_assert(tor_mem_is_zero(
+ (const char*)(chan->conn->handshake_state->
+ authenticated_ed25519_peer_id.pubkey), 32));
+ /* If the client never authenticated, it's a tor client or bridge
+ * relay, and we must not use it for EXTEND requests (nor could we, as
+ * there are no authenticated peer IDs) */
+ channel_mark_client(TLS_CHAN_TO_BASE(chan));
+ channel_set_circid_type(TLS_CHAN_TO_BASE(chan), NULL,
+ chan->conn->link_proto < MIN_LINK_PROTO_FOR_WIDE_CIRC_IDS);
+
+ connection_or_init_conn_from_address(chan->conn,
+ &(chan->conn->base_.addr),
+ chan->conn->base_.port,
+ /* zero, checked above */
+ (const char*)(chan->conn->handshake_state->
+ authenticated_rsa_peer_id),
+ NULL, /* Ed25519 ID: Also checked as zero */
+ 0);
+ }
+ }
+ }
+
+ /* Decode the cell. */
+ timestamp = ntohl(get_uint32(cell->payload));
- if (labs(now - chan->conn->handshake_state->sent_versions_at) < 180) {
++ const time_t sent_versions_at =
++ chan->conn->handshake_state->sent_versions_at;
++ if (now > sent_versions_at && (now - sent_versions_at) < 180) {
++ /* If we have gotten the NETINFO cell reasonably soon after having
++ * sent our VERSIONS cell, maybe we can learn skew information from it. */
+ apparent_skew = now - timestamp;
+ }
+
+ my_addr_type = (uint8_t) cell->payload[4];
+ my_addr_len = (uint8_t) cell->payload[5];
+ my_addr_ptr = (uint8_t*) cell->payload + 6;
+ end = cell->payload + CELL_PAYLOAD_SIZE;
+ cp = cell->payload + 6 + my_addr_len;
+
+ /* We used to check:
+ * if (my_addr_len >= CELL_PAYLOAD_SIZE - 6) {
+ *
+ * This is actually never going to happen, since my_addr_len is at most 255,
+ * and CELL_PAYLOAD_LEN - 6 is 503. So we know that cp is < end. */
+
+ if (my_addr_type == RESOLVED_TYPE_IPV4 && my_addr_len == 4) {
+ tor_addr_from_ipv4n(&my_apparent_addr, get_uint32(my_addr_ptr));
+
+ if (!get_options()->BridgeRelay && me &&
+ get_uint32(my_addr_ptr) == htonl(me->addr)) {
+ TLS_CHAN_TO_BASE(chan)->is_canonical_to_peer = 1;
+ }
+
+ } else if (my_addr_type == RESOLVED_TYPE_IPV6 && my_addr_len == 16) {
+ tor_addr_from_ipv6_bytes(&my_apparent_addr, (const char *) my_addr_ptr);
+
+ if (!get_options()->BridgeRelay && me &&
+ !tor_addr_is_null(&me->ipv6_addr) &&
+ tor_addr_eq(&my_apparent_addr, &me->ipv6_addr)) {
+ TLS_CHAN_TO_BASE(chan)->is_canonical_to_peer = 1;
+ }
+ }
+
+ n_other_addrs = (uint8_t) *cp++;
+ while (n_other_addrs && cp < end-2) {
+ /* Consider all the other addresses; if any matches, this connection is
+ * "canonical." */
+ tor_addr_t addr;
+ const uint8_t *next =
+ decode_address_from_payload(&addr, cp, (int)(end-cp));
+ if (next == NULL) {
+ log_fn(LOG_PROTOCOL_WARN, LD_OR,
+ "Bad address in netinfo cell; closing connection.");
+ connection_or_close_for_error(chan->conn, 0);
+ return;
+ }
+ /* A relay can connect from anywhere and be canonical, so
+ * long as it tells you from where it came. This may sound a bit
+ * concerning... but that's what "canonical" means: that the
+ * address is one that the relay itself has claimed. The relay
+ * might be doing something funny, but nobody else is doing a MITM
+ * on the relay's TCP.
+ */
+ if (tor_addr_eq(&addr, &(chan->conn->real_addr))) {
+ connection_or_set_canonical(chan->conn, 1);
+ break;
+ }
+ cp = next;
+ --n_other_addrs;
+ }
+
+ if (me && !TLS_CHAN_TO_BASE(chan)->is_canonical_to_peer &&
+ channel_is_canonical(TLS_CHAN_TO_BASE(chan))) {
+ const char *descr =
+ TLS_CHAN_TO_BASE(chan)->get_remote_descr(TLS_CHAN_TO_BASE(chan), 0);
+ log_info(LD_OR,
+ "We made a connection to a relay at %s (fp=%s) but we think "
+ "they will not consider this connection canonical. They "
+ "think we are at %s, but we think its %s.",
+ safe_str(descr),
+ safe_str(hex_str(identity_digest, DIGEST_LEN)),
+ safe_str(tor_addr_is_null(&my_apparent_addr) ?
+ "<none>" : fmt_and_decorate_addr(&my_apparent_addr)),
+ safe_str(fmt_addr32(me->addr)));
+ }
+
+ /* Act on apparent skew. */
+ /** Warn when we get a netinfo skew with at least this value. */
+#define NETINFO_NOTICE_SKEW 3600
- if (labs(apparent_skew) > NETINFO_NOTICE_SKEW &&
++ if (time_abs(apparent_skew) > NETINFO_NOTICE_SKEW &&
+ (started_here ||
+ connection_or_digest_is_known_relay(chan->conn->identity_digest))) {
+ int trusted = router_digest_is_trusted_dir(chan->conn->identity_digest);
+ clock_skew_warning(TO_CONN(chan->conn), apparent_skew, trusted, LD_GENERAL,
+ "NETINFO cell", "OR");
+ }
+
+ /* XXX maybe act on my_apparent_addr, if the source is sufficiently
+ * trustworthy. */
+
+ if (! chan->conn->handshake_state->sent_netinfo) {
+ /* If we were prepared to authenticate, but we never got an AUTH_CHALLENGE
+ * cell, then we would not previously have sent a NETINFO cell. Do so
+ * now. */
+ if (connection_or_send_netinfo(chan->conn) < 0) {
+ connection_or_close_for_error(chan->conn, 0);
+ return;
+ }
+ }
+
+ if (connection_or_set_state_open(chan->conn) < 0) {
+ log_fn(LOG_PROTOCOL_WARN, LD_OR,
+ "Got good NETINFO cell from %s:%d; but "
+ "was unable to make the OR connection become open.",
+ safe_str_client(chan->conn->base_.address),
+ chan->conn->base_.port);
+ connection_or_close_for_error(chan->conn, 0);
+ } else {
+ log_info(LD_OR,
+ "Got good NETINFO cell from %s:%d; OR connection is now "
+ "open, using protocol version %d. Its ID digest is %s. "
+ "Our address is apparently %s.",
+ safe_str_client(chan->conn->base_.address),
+ chan->conn->base_.port,
+ (int)(chan->conn->link_proto),
+ hex_str(identity_digest, DIGEST_LEN),
+ tor_addr_is_null(&my_apparent_addr) ?
+ "<none>" :
+ safe_str_client(fmt_and_decorate_addr(&my_apparent_addr)));
+ }
+ assert_connection_ok(TO_CONN(chan->conn),time(NULL));
+}
+
+/** Types of certificates that we know how to parse from CERTS cells. Each
+ * type corresponds to a different encoding format. */
+typedef enum cert_encoding_t {
+ CERT_ENCODING_UNKNOWN, /**< We don't recognize this. */
+ CERT_ENCODING_X509, /**< It's an RSA key, signed with RSA, encoded in x509.
+ * (Actually, it might not be RSA. We test that later.) */
+ CERT_ENCODING_ED25519, /**< It's something signed with an Ed25519 key,
+ * encoded asa a tor_cert_t.*/
+ CERT_ENCODING_RSA_CROSSCERT, /**< It's an Ed key signed with an RSA key. */
+} cert_encoding_t;
+
+/**
+ * Given one of the certificate type codes used in a CERTS cell,
+ * return the corresponding cert_encoding_t that we should use to parse
+ * the certificate.
+ */
+static cert_encoding_t
+certs_cell_typenum_to_cert_type(int typenum)
+{
+ switch (typenum) {
+ case CERTTYPE_RSA1024_ID_LINK:
+ case CERTTYPE_RSA1024_ID_ID:
+ case CERTTYPE_RSA1024_ID_AUTH:
+ return CERT_ENCODING_X509;
+ case CERTTYPE_ED_ID_SIGN:
+ case CERTTYPE_ED_SIGN_LINK:
+ case CERTTYPE_ED_SIGN_AUTH:
+ return CERT_ENCODING_ED25519;
+ case CERTTYPE_RSA1024_ID_EDID:
+ return CERT_ENCODING_RSA_CROSSCERT;
+ default:
+ return CERT_ENCODING_UNKNOWN;
+ }
+}
+
+/**
+ * Process a CERTS cell from a channel.
+ *
+ * This function is called to process an incoming CERTS cell on a
+ * channel_tls_t:
+ *
+ * If the other side should not have sent us a CERTS cell, or the cell is
+ * malformed, or it is supposed to authenticate the TLS key but it doesn't,
+ * then mark the connection.
+ *
+ * If the cell has a good cert chain and we're doing a v3 handshake, then
+ * store the certificates in or_handshake_state. If this is the client side
+ * of the connection, we then authenticate the server or mark the connection.
+ * If it's the server side, wait for an AUTHENTICATE cell.
+ */
+STATIC void
+channel_tls_process_certs_cell(var_cell_t *cell, channel_tls_t *chan)
+{
+#define MAX_CERT_TYPE_WANTED CERTTYPE_RSA1024_ID_EDID
+ /* These arrays will be sparse, since a cert type can be at most one
+ * of ed/x509 */
+ tor_x509_cert_t *x509_certs[MAX_CERT_TYPE_WANTED + 1];
+ tor_cert_t *ed_certs[MAX_CERT_TYPE_WANTED + 1];
+ uint8_t *rsa_ed_cc_cert = NULL;
+ size_t rsa_ed_cc_cert_len = 0;
+
+ int n_certs, i;
+ certs_cell_t *cc = NULL;
+
+ int send_netinfo = 0, started_here = 0;
+
+ memset(x509_certs, 0, sizeof(x509_certs));
+ memset(ed_certs, 0, sizeof(ed_certs));
+ tor_assert(cell);
+ tor_assert(chan);
+ tor_assert(chan->conn);
+
+#define ERR(s) \
+ do { \
+ log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL, \
+ "Received a bad CERTS cell from %s:%d: %s", \
+ safe_str(chan->conn->base_.address), \
+ chan->conn->base_.port, (s)); \
+ connection_or_close_for_error(chan->conn, 0); \
+ goto err; \
+ } while (0)
+
+ /* Can't use connection_or_nonopen_was_started_here(); its conn->tls
+ * check looks like it breaks
+ * test_link_handshake_recv_certs_ok_server(). */
+ started_here = chan->conn->handshake_state->started_here;
+
+ if (chan->conn->base_.state != OR_CONN_STATE_OR_HANDSHAKING_V3)
+ ERR("We're not doing a v3 handshake!");
+ if (chan->conn->link_proto < 3)
+ ERR("We're not using link protocol >= 3");
+ if (chan->conn->handshake_state->received_certs_cell)
+ ERR("We already got one");
+ if (chan->conn->handshake_state->authenticated) {
+ /* Should be unreachable, but let's make sure. */
+ ERR("We're already authenticated!");
+ }
+ if (cell->payload_len < 1)
+ ERR("It had no body");
+ if (cell->circ_id)
+ ERR("It had a nonzero circuit ID");
+
+ if (certs_cell_parse(&cc, cell->payload, cell->payload_len) < 0)
+ ERR("It couldn't be parsed.");
+
+ n_certs = cc->n_certs;
+
+ for (i = 0; i < n_certs; ++i) {
+ certs_cell_cert_t *c = certs_cell_get_certs(cc, i);
+
+ uint16_t cert_type = c->cert_type;
+ uint16_t cert_len = c->cert_len;
+ uint8_t *cert_body = certs_cell_cert_getarray_body(c);
+
+ if (cert_type > MAX_CERT_TYPE_WANTED)
+ continue;
+ const cert_encoding_t ct = certs_cell_typenum_to_cert_type(cert_type);
+ switch (ct) {
+ default:
+ case CERT_ENCODING_UNKNOWN:
+ break;
+ case CERT_ENCODING_X509: {
+ tor_x509_cert_t *x509_cert = tor_x509_cert_decode(cert_body, cert_len);
+ if (!x509_cert) {
+ log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
+ "Received undecodable certificate in CERTS cell from %s:%d",
+ safe_str(chan->conn->base_.address),
+ chan->conn->base_.port);
+ } else {
+ if (x509_certs[cert_type]) {
+ tor_x509_cert_free(x509_cert);
+ ERR("Duplicate x509 certificate");
+ } else {
+ x509_certs[cert_type] = x509_cert;
+ }
+ }
+ break;
+ }
+ case CERT_ENCODING_ED25519: {
+ tor_cert_t *ed_cert = tor_cert_parse(cert_body, cert_len);
+ if (!ed_cert) {
+ log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
+ "Received undecodable Ed certificate "
+ "in CERTS cell from %s:%d",
+ safe_str(chan->conn->base_.address),
+ chan->conn->base_.port);
+ } else {
+ if (ed_certs[cert_type]) {
+ tor_cert_free(ed_cert);
+ ERR("Duplicate Ed25519 certificate");
+ } else {
+ ed_certs[cert_type] = ed_cert;
+ }
+ }
+ break;
+ }
+
+ case CERT_ENCODING_RSA_CROSSCERT: {
+ if (rsa_ed_cc_cert) {
+ ERR("Duplicate RSA->Ed25519 crosscert");
+ } else {
+ rsa_ed_cc_cert = tor_memdup(cert_body, cert_len);
+ rsa_ed_cc_cert_len = cert_len;
+ }
+ break;
+ }
+ }
+ }
+
+ /* Move the certificates we (might) want into the handshake_state->certs
+ * structure. */
+ tor_x509_cert_t *id_cert = x509_certs[CERTTYPE_RSA1024_ID_ID];
+ tor_x509_cert_t *auth_cert = x509_certs[CERTTYPE_RSA1024_ID_AUTH];
+ tor_x509_cert_t *link_cert = x509_certs[CERTTYPE_RSA1024_ID_LINK];
+ chan->conn->handshake_state->certs->auth_cert = auth_cert;
+ chan->conn->handshake_state->certs->link_cert = link_cert;
+ chan->conn->handshake_state->certs->id_cert = id_cert;
+ x509_certs[CERTTYPE_RSA1024_ID_ID] =
+ x509_certs[CERTTYPE_RSA1024_ID_AUTH] =
+ x509_certs[CERTTYPE_RSA1024_ID_LINK] = NULL;
+
+ tor_cert_t *ed_id_sign = ed_certs[CERTTYPE_ED_ID_SIGN];
+ tor_cert_t *ed_sign_link = ed_certs[CERTTYPE_ED_SIGN_LINK];
+ tor_cert_t *ed_sign_auth = ed_certs[CERTTYPE_ED_SIGN_AUTH];
+ chan->conn->handshake_state->certs->ed_id_sign = ed_id_sign;
+ chan->conn->handshake_state->certs->ed_sign_link = ed_sign_link;
+ chan->conn->handshake_state->certs->ed_sign_auth = ed_sign_auth;
+ ed_certs[CERTTYPE_ED_ID_SIGN] =
+ ed_certs[CERTTYPE_ED_SIGN_LINK] =
+ ed_certs[CERTTYPE_ED_SIGN_AUTH] = NULL;
+
+ chan->conn->handshake_state->certs->ed_rsa_crosscert = rsa_ed_cc_cert;
+ chan->conn->handshake_state->certs->ed_rsa_crosscert_len =
+ rsa_ed_cc_cert_len;
+ rsa_ed_cc_cert = NULL;
+
+ int severity;
+ /* Note that this warns more loudly about time and validity if we were
+ * _trying_ to connect to an authority, not necessarily if we _did_ connect
+ * to one. */
+ if (started_here &&
+ router_digest_is_trusted_dir(TLS_CHAN_TO_BASE(chan)->identity_digest))
+ severity = LOG_WARN;
+ else
+ severity = LOG_PROTOCOL_WARN;
+
+ const ed25519_public_key_t *checked_ed_id = NULL;
+ const common_digests_t *checked_rsa_id = NULL;
+ or_handshake_certs_check_both(severity,
+ chan->conn->handshake_state->certs,
+ chan->conn->tls,
+ time(NULL),
+ &checked_ed_id,
+ &checked_rsa_id);
+
+ if (!checked_rsa_id)
+ ERR("Invalid certificate chain!");
+
+ if (started_here) {
+ /* No more information is needed. */
+
+ chan->conn->handshake_state->authenticated = 1;
+ chan->conn->handshake_state->authenticated_rsa = 1;
+ {
+ const common_digests_t *id_digests = checked_rsa_id;
+ crypto_pk_t *identity_rcvd;
+ if (!id_digests)
+ ERR("Couldn't compute digests for key in ID cert");
+
+ identity_rcvd = tor_tls_cert_get_key(id_cert);
+ if (!identity_rcvd) {
+ ERR("Couldn't get RSA key from ID cert.");
+ }
+ memcpy(chan->conn->handshake_state->authenticated_rsa_peer_id,
+ id_digests->d[DIGEST_SHA1], DIGEST_LEN);
+ channel_set_circid_type(TLS_CHAN_TO_BASE(chan), identity_rcvd,
+ chan->conn->link_proto < MIN_LINK_PROTO_FOR_WIDE_CIRC_IDS);
+ crypto_pk_free(identity_rcvd);
+ }
+
+ if (checked_ed_id) {
+ chan->conn->handshake_state->authenticated_ed25519 = 1;
+ memcpy(&chan->conn->handshake_state->authenticated_ed25519_peer_id,
+ checked_ed_id, sizeof(ed25519_public_key_t));
+ }
+
+ log_debug(LD_HANDSHAKE, "calling client_learned_peer_id from "
+ "process_certs_cell");
+
+ if (connection_or_client_learned_peer_id(chan->conn,
+ chan->conn->handshake_state->authenticated_rsa_peer_id,
+ checked_ed_id) < 0)
+ ERR("Problem setting or checking peer id");
+
+ log_info(LD_HANDSHAKE,
+ "Got some good certificates from %s:%d: Authenticated it with "
+ "RSA%s",
+ safe_str(chan->conn->base_.address), chan->conn->base_.port,
+ checked_ed_id ? " and Ed25519" : "");
+
+ if (!public_server_mode(get_options())) {
+ /* If we initiated the connection and we are not a public server, we
+ * aren't planning to authenticate at all. At this point we know who we
+ * are talking to, so we can just send a netinfo now. */
+ send_netinfo = 1;
+ }
+ } else {
+ /* We can't call it authenticated till we see an AUTHENTICATE cell. */
+ log_info(LD_OR,
+ "Got some good RSA%s certificates from %s:%d. "
+ "Waiting for AUTHENTICATE.",
+ checked_ed_id ? " and Ed25519" : "",
+ safe_str(chan->conn->base_.address),
+ chan->conn->base_.port);
+ /* XXXX check more stuff? */
+ }
+
+ chan->conn->handshake_state->received_certs_cell = 1;
+
+ if (send_netinfo) {
+ if (connection_or_send_netinfo(chan->conn) < 0) {
+ log_warn(LD_OR, "Couldn't send netinfo cell");
+ connection_or_close_for_error(chan->conn, 0);
+ goto err;
+ }
+ }
+
+ err:
+ for (unsigned u = 0; u < ARRAY_LENGTH(x509_certs); ++u) {
+ tor_x509_cert_free(x509_certs[u]);
+ }
+ for (unsigned u = 0; u < ARRAY_LENGTH(ed_certs); ++u) {
+ tor_cert_free(ed_certs[u]);
+ }
+ tor_free(rsa_ed_cc_cert);
+ certs_cell_free(cc);
+#undef ERR
+}
+
+/**
+ * Process an AUTH_CHALLENGE cell from a channel_tls_t.
+ *
+ * This function is called to handle an incoming AUTH_CHALLENGE cell on a
+ * channel_tls_t; if we weren't supposed to get one (for example, because we're
+ * not the originator of the channel), or it's ill-formed, or we aren't doing
+ * a v3 handshake, mark the channel. If the cell is well-formed but we don't
+ * want to authenticate, just drop it. If the cell is well-formed *and* we
+ * want to authenticate, send an AUTHENTICATE cell and then a NETINFO cell.
+ */
+STATIC void
+channel_tls_process_auth_challenge_cell(var_cell_t *cell, channel_tls_t *chan)
+{
+ int n_types, i, use_type = -1;
+ auth_challenge_cell_t *ac = NULL;
+
+ tor_assert(cell);
+ tor_assert(chan);
+ tor_assert(chan->conn);
+
+#define ERR(s) \
+ do { \
+ log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL, \
+ "Received a bad AUTH_CHALLENGE cell from %s:%d: %s", \
+ safe_str(chan->conn->base_.address), \
+ chan->conn->base_.port, (s)); \
+ connection_or_close_for_error(chan->conn, 0); \
+ goto done; \
+ } while (0)
+
+ if (chan->conn->base_.state != OR_CONN_STATE_OR_HANDSHAKING_V3)
+ ERR("We're not currently doing a v3 handshake");
+ if (chan->conn->link_proto < 3)
+ ERR("We're not using link protocol >= 3");
+ if (!(chan->conn->handshake_state->started_here))
+ ERR("We didn't originate this connection");
+ if (chan->conn->handshake_state->received_auth_challenge)
+ ERR("We already received one");
+ if (!(chan->conn->handshake_state->received_certs_cell))
+ ERR("We haven't gotten a CERTS cell yet");
+ if (cell->circ_id)
+ ERR("It had a nonzero circuit ID");
+
+ if (auth_challenge_cell_parse(&ac, cell->payload, cell->payload_len) < 0)
+ ERR("It was not well-formed.");
+
+ n_types = ac->n_methods;
+
+ /* Now see if there is an authentication type we can use */
+ for (i = 0; i < n_types; ++i) {
+ uint16_t authtype = auth_challenge_cell_get_methods(ac, i);
+ if (authchallenge_type_is_supported(authtype)) {
+ if (use_type == -1 ||
+ authchallenge_type_is_better(authtype, use_type)) {
+ use_type = authtype;
+ }
+ }
+ }
+
+ chan->conn->handshake_state->received_auth_challenge = 1;
+
+ if (! public_server_mode(get_options())) {
+ /* If we're not a public server then we don't want to authenticate on a
+ connection we originated, and we already sent a NETINFO cell when we
+ got the CERTS cell. We have nothing more to do. */
+ goto done;
+ }
+
+ if (use_type >= 0) {
+ log_info(LD_OR,
+ "Got an AUTH_CHALLENGE cell from %s:%d: Sending "
+ "authentication type %d",
+ safe_str(chan->conn->base_.address),
+ chan->conn->base_.port,
+ use_type);
+
+ if (connection_or_send_authenticate_cell(chan->conn, use_type) < 0) {
+ log_warn(LD_OR,
+ "Couldn't send authenticate cell");
+ connection_or_close_for_error(chan->conn, 0);
+ goto done;
+ }
+ } else {
+ log_info(LD_OR,
+ "Got an AUTH_CHALLENGE cell from %s:%d, but we don't "
+ "know any of its authentication types. Not authenticating.",
+ safe_str(chan->conn->base_.address),
+ chan->conn->base_.port);
+ }
+
+ if (connection_or_send_netinfo(chan->conn) < 0) {
+ log_warn(LD_OR, "Couldn't send netinfo cell");
+ connection_or_close_for_error(chan->conn, 0);
+ goto done;
+ }
+
+ done:
+ auth_challenge_cell_free(ac);
+
+#undef ERR
+}
+
+/**
+ * Process an AUTHENTICATE cell from a channel_tls_t.
+ *
+ * If it's ill-formed or we weren't supposed to get one or we're not doing a
+ * v3 handshake, then mark the connection. If it does not authenticate the
+ * other side of the connection successfully (because it isn't signed right,
+ * we didn't get a CERTS cell, etc) mark the connection. Otherwise, accept
+ * the identity of the router on the other side of the connection.
+ */
+STATIC void
+channel_tls_process_authenticate_cell(var_cell_t *cell, channel_tls_t *chan)
+{
+ var_cell_t *expected_cell = NULL;
+ const uint8_t *auth;
+ int authlen;
+ int authtype;
+ int bodylen;
+
+ tor_assert(cell);
+ tor_assert(chan);
+ tor_assert(chan->conn);
+
+#define ERR(s) \
+ do { \
+ log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL, \
+ "Received a bad AUTHENTICATE cell from %s:%d: %s", \
+ safe_str(chan->conn->base_.address), \
+ chan->conn->base_.port, (s)); \
+ connection_or_close_for_error(chan->conn, 0); \
+ var_cell_free(expected_cell); \
+ return; \
+ } while (0)
+
+ if (chan->conn->base_.state != OR_CONN_STATE_OR_HANDSHAKING_V3)
+ ERR("We're not doing a v3 handshake");
+ if (chan->conn->link_proto < 3)
+ ERR("We're not using link protocol >= 3");
+ if (chan->conn->handshake_state->started_here)
+ ERR("We originated this connection");
+ if (chan->conn->handshake_state->received_authenticate)
+ ERR("We already got one!");
+ if (chan->conn->handshake_state->authenticated) {
+ /* Should be impossible given other checks */
+ ERR("The peer is already authenticated");
+ }
+ if (!(chan->conn->handshake_state->received_certs_cell))
+ ERR("We never got a certs cell");
+ if (chan->conn->handshake_state->certs->id_cert == NULL)
+ ERR("We never got an identity certificate");
+ if (cell->payload_len < 4)
+ ERR("Cell was way too short");
+
+ auth = cell->payload;
+ {
+ uint16_t type = ntohs(get_uint16(auth));
+ uint16_t len = ntohs(get_uint16(auth+2));
+ if (4 + len > cell->payload_len)
+ ERR("Authenticator was truncated");
+
+ if (! authchallenge_type_is_supported(type))
+ ERR("Authenticator type was not recognized");
+ authtype = type;
+
+ auth += 4;
+ authlen = len;
+ }
+
+ if (authlen < V3_AUTH_BODY_LEN + 1)
+ ERR("Authenticator was too short");
+
+ expected_cell = connection_or_compute_authenticate_cell_body(
+ chan->conn, authtype, NULL, NULL, 1);
+ if (! expected_cell)
+ ERR("Couldn't compute expected AUTHENTICATE cell body");
+
+ int sig_is_rsa;
+ if (authtype == AUTHTYPE_RSA_SHA256_TLSSECRET ||
+ authtype == AUTHTYPE_RSA_SHA256_RFC5705) {
+ bodylen = V3_AUTH_BODY_LEN;
+ sig_is_rsa = 1;
+ } else {
+ tor_assert(authtype == AUTHTYPE_ED25519_SHA256_RFC5705);
+ /* Our earlier check had better have made sure we had room
+ * for an ed25519 sig (inadvertently) */
+ tor_assert(V3_AUTH_BODY_LEN > ED25519_SIG_LEN);
+ bodylen = authlen - ED25519_SIG_LEN;
+ sig_is_rsa = 0;
+ }
+ if (expected_cell->payload_len != bodylen+4) {
+ ERR("Expected AUTHENTICATE cell body len not as expected.");
+ }
+
+ /* Length of random part. */
+ if (BUG(bodylen < 24)) {
+ // LCOV_EXCL_START
+ ERR("Bodylen is somehow less than 24, which should really be impossible");
+ // LCOV_EXCL_STOP
+ }
+
+ if (tor_memneq(expected_cell->payload+4, auth, bodylen-24))
+ ERR("Some field in the AUTHENTICATE cell body was not as expected");
+
+ if (sig_is_rsa) {
+ if (chan->conn->handshake_state->certs->ed_id_sign != NULL)
+ ERR("RSA-signed AUTHENTICATE response provided with an ED25519 cert");
+
+ if (chan->conn->handshake_state->certs->auth_cert == NULL)
+ ERR("We never got an RSA authentication certificate");
+
+ crypto_pk_t *pk = tor_tls_cert_get_key(
+ chan->conn->handshake_state->certs->auth_cert);
+ char d[DIGEST256_LEN];
+ char *signed_data;
+ size_t keysize;
+ int signed_len;
+
+ if (! pk) {
+ ERR("Couldn't get RSA key from AUTH cert.");
+ }
+ crypto_digest256(d, (char*)auth, V3_AUTH_BODY_LEN, DIGEST_SHA256);
+
+ keysize = crypto_pk_keysize(pk);
+ signed_data = tor_malloc(keysize);
+ signed_len = crypto_pk_public_checksig(pk, signed_data, keysize,
+ (char*)auth + V3_AUTH_BODY_LEN,
+ authlen - V3_AUTH_BODY_LEN);
+ crypto_pk_free(pk);
+ if (signed_len < 0) {
+ tor_free(signed_data);
+ ERR("RSA signature wasn't valid");
+ }
+ if (signed_len < DIGEST256_LEN) {
+ tor_free(signed_data);
+ ERR("Not enough data was signed");
+ }
+ /* Note that we deliberately allow *more* than DIGEST256_LEN bytes here,
+ * in case they're later used to hold a SHA3 digest or something. */
+ if (tor_memneq(signed_data, d, DIGEST256_LEN)) {
+ tor_free(signed_data);
+ ERR("Signature did not match data to be signed.");
+ }
+ tor_free(signed_data);
+ } else {
+ if (chan->conn->handshake_state->certs->ed_id_sign == NULL)
+ ERR("We never got an Ed25519 identity certificate.");
+ if (chan->conn->handshake_state->certs->ed_sign_auth == NULL)
+ ERR("We never got an Ed25519 authentication certificate.");
+
+ const ed25519_public_key_t *authkey =
+ &chan->conn->handshake_state->certs->ed_sign_auth->signed_key;
+ ed25519_signature_t sig;
+ tor_assert(authlen > ED25519_SIG_LEN);
+ memcpy(&sig.sig, auth + authlen - ED25519_SIG_LEN, ED25519_SIG_LEN);
+ if (ed25519_checksig(&sig, auth, authlen - ED25519_SIG_LEN, authkey)<0) {
+ ERR("Ed25519 signature wasn't valid.");
+ }
+ }
+
+ /* Okay, we are authenticated. */
+ chan->conn->handshake_state->received_authenticate = 1;
+ chan->conn->handshake_state->authenticated = 1;
+ chan->conn->handshake_state->authenticated_rsa = 1;
+ chan->conn->handshake_state->digest_received_data = 0;
+ {
+ tor_x509_cert_t *id_cert = chan->conn->handshake_state->certs->id_cert;
+ crypto_pk_t *identity_rcvd = tor_tls_cert_get_key(id_cert);
+ const common_digests_t *id_digests = tor_x509_cert_get_id_digests(id_cert);
+ const ed25519_public_key_t *ed_identity_received = NULL;
+
+ if (! sig_is_rsa) {
+ chan->conn->handshake_state->authenticated_ed25519 = 1;
+ ed_identity_received =
+ &chan->conn->handshake_state->certs->ed_id_sign->signing_key;
+ memcpy(&chan->conn->handshake_state->authenticated_ed25519_peer_id,
+ ed_identity_received, sizeof(ed25519_public_key_t));
+ }
+
+ /* This must exist; we checked key type when reading the cert. */
+ tor_assert(id_digests);
+
+ memcpy(chan->conn->handshake_state->authenticated_rsa_peer_id,
+ id_digests->d[DIGEST_SHA1], DIGEST_LEN);
+
+ channel_set_circid_type(TLS_CHAN_TO_BASE(chan), identity_rcvd,
+ chan->conn->link_proto < MIN_LINK_PROTO_FOR_WIDE_CIRC_IDS);
+ crypto_pk_free(identity_rcvd);
+
+ log_debug(LD_HANDSHAKE,
+ "Calling connection_or_init_conn_from_address for %s "
+ " from %s, with%s ed25519 id.",
+ safe_str(chan->conn->base_.address),
+ __func__,
+ ed_identity_received ? "" : "out");
+
+ connection_or_init_conn_from_address(chan->conn,
+ &(chan->conn->base_.addr),
+ chan->conn->base_.port,
+ (const char*)(chan->conn->handshake_state->
+ authenticated_rsa_peer_id),
+ ed_identity_received,
+ 0);
+
+ log_debug(LD_HANDSHAKE,
+ "Got an AUTHENTICATE cell from %s:%d, type %d: Looks good.",
+ safe_str(chan->conn->base_.address),
+ chan->conn->base_.port,
+ authtype);
+ }
+
+ var_cell_free(expected_cell);
+
+#undef ERR
+}
