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- /* Copyright 2004 Roger Dingledine */
- /* See LICENSE for licensing information */
- /* $Id$ */
- #include "or.h"
- /* send the introduce cell */
- void
- rend_client_introcirc_is_open(circuit_t *circ)
- {
- assert(circ->purpose == CIRCUIT_PURPOSE_C_INTRODUCING);
- assert(CIRCUIT_IS_ORIGIN(circ) && circ->cpath);
- log_fn(LOG_INFO,"introcirc is open");
- connection_ap_attach_pending();
- }
- /* send the establish-rendezvous cell. if it fails, mark
- * the circ for close and return -1. else return 0.
- */
- int
- rend_client_send_establish_rendezvous(circuit_t *circ)
- {
- assert(circ->purpose == CIRCUIT_PURPOSE_C_ESTABLISH_REND);
- log_fn(LOG_INFO, "Sending an ESTABLISH_RENDEZVOUS cell");
- if (crypto_rand(REND_COOKIE_LEN, circ->rend_cookie)<0) {
- log_fn(LOG_WARN, "Couldn't get random cookie");
- circuit_mark_for_close(circ);
- return -1;
- }
- if (connection_edge_send_command(NULL,circ,
- RELAY_COMMAND_ESTABLISH_RENDEZVOUS,
- circ->rend_cookie, REND_COOKIE_LEN,
- circ->cpath->prev)<0) {
- /* circ is already marked for close */
- log_fn(LOG_WARN, "Couldn't send ESTABLISH_RENDEZVOUS cell");
- return -1;
- }
- return 0;
- }
- /* Called when we're trying to connect an ap conn; sends an INTRODUCE1 cell
- * down introcirc if possible.
- */
- int
- rend_client_send_introduction(circuit_t *introcirc, circuit_t *rendcirc) {
- int payload_len, r;
- char payload[RELAY_PAYLOAD_SIZE];
- char tmp[(MAX_NICKNAME_LEN+1)+REND_COOKIE_LEN+DH_KEY_LEN];
- rend_cache_entry_t *entry;
- crypt_path_t *cpath;
- assert(introcirc->purpose == CIRCUIT_PURPOSE_C_INTRODUCING);
- assert(rendcirc->purpose == CIRCUIT_PURPOSE_C_REND_READY);
- assert(!rend_cmp_service_ids(introcirc->rend_query, rendcirc->rend_query));
- if(rend_cache_lookup_entry(introcirc->rend_query, &entry) < 1) {
- log_fn(LOG_WARN,"query '%s' didn't have valid rend desc in cache. Failing.",
- introcirc->rend_query);
- goto err;
- }
- /* first 20 bytes of payload are the hash of bob's pk */
- if (crypto_pk_get_digest(entry->parsed->pk, payload)<0) {
- log_fn(LOG_WARN, "Couldn't hash public key.");
- goto err;
- }
- /* Initialize the pending_final_cpath and start the DH handshake. */
- cpath = rendcirc->build_state->pending_final_cpath =
- tor_malloc_zero(sizeof(crypt_path_t));
- if (!(cpath->handshake_state = crypto_dh_new())) {
- log_fn(LOG_WARN, "Couldn't allocate DH");
- goto err;
- }
- if (crypto_dh_generate_public(cpath->handshake_state)<0) {
- log_fn(LOG_WARN, "Couldn't generate g^x");
- goto err;
- }
- /* write the remaining items into tmp */
- strncpy(tmp, rendcirc->build_state->chosen_exit, (MAX_NICKNAME_LEN+1)); /* nul pads */
- memcpy(tmp+MAX_NICKNAME_LEN+1, rendcirc->rend_cookie, REND_COOKIE_LEN);
- if (crypto_dh_get_public(cpath->handshake_state,
- tmp+MAX_NICKNAME_LEN+1+REND_COOKIE_LEN,
- DH_KEY_LEN)<0) {
- log_fn(LOG_WARN, "Couldn't extract g^x");
- goto err;
- }
- r = crypto_pk_public_hybrid_encrypt(entry->parsed->pk, tmp,
- MAX_NICKNAME_LEN+1+REND_COOKIE_LEN+DH_KEY_LEN,
- payload+DIGEST_LEN,
- PK_PKCS1_OAEP_PADDING, 0);
- if (r<0) {
- log_fn(LOG_WARN,"hybrid pk encrypt failed.");
- goto err;
- }
- payload_len = DIGEST_LEN + r;
- if (connection_edge_send_command(NULL, introcirc,
- RELAY_COMMAND_INTRODUCE1,
- payload, payload_len,
- introcirc->cpath->prev)<0) {
- /* introcirc is already marked for close. leave rendcirc alone. */
- log_fn(LOG_WARN, "Couldn't send INTRODUCE1 cell");
- return -1;
- }
- /* we don't need it anymore, plus it's been used. send the destroy. */
- circuit_mark_for_close(introcirc);
- return 0;
- err:
- circuit_mark_for_close(introcirc);
- circuit_mark_for_close(rendcirc);
- return -1;
- }
- /* send the rendezvous cell */
- void
- rend_client_rendcirc_is_open(circuit_t *circ)
- {
- assert(circ->purpose == CIRCUIT_PURPOSE_C_ESTABLISH_REND);
- assert(CIRCUIT_IS_ORIGIN(circ));
- log_fn(LOG_INFO,"rendcirc is open");
- /* generate a rendezvous cookie, store it in circ */
- if (rend_client_send_establish_rendezvous(circ) < 0) {
- return;
- }
- connection_ap_attach_pending();
- }
- /* Called when we receive a RENDEZVOUS_ESTABLISHED cell; changes the state of
- * the circuit to C_REND_READY.
- */
- int
- rend_client_rendezvous_acked(circuit_t *circ, const char *request, int request_len)
- {
- /* we just got an ack for our establish-rendezvous. switch purposes. */
- if(circ->purpose != CIRCUIT_PURPOSE_C_ESTABLISH_REND) {
- log_fn(LOG_WARN,"Got a rendezvous ack when we weren't expecting one. Closing circ.");
- circuit_mark_for_close(circ);
- return -1;
- }
- log_fn(LOG_INFO,"Got rendezvous ack. This circuit is now ready for rendezvous.");
- circ->purpose = CIRCUIT_PURPOSE_C_REND_READY;
- return 0;
- }
- /* bob sent us a rendezvous cell, join the circs. */
- int
- rend_client_receive_rendezvous(circuit_t *circ, const char *request, int request_len)
- {
- connection_t *apconn;
- crypt_path_t *hop;
- char keys[DIGEST_LEN+CPATH_KEY_MATERIAL_LEN];
- if(circ->purpose != CIRCUIT_PURPOSE_C_REND_READY ||
- !circ->build_state->pending_final_cpath) {
- log_fn(LOG_WARN,"Got rendezvous2 cell from Bob, but not expecting it. Closing.");
- circuit_mark_for_close(circ);
- return -1;
- }
- if (request_len != DH_KEY_LEN+DIGEST_LEN) {
- log_fn(LOG_WARN,"Incorrect length (%d) on RENDEZVOUS2 cell.",request_len);
- goto err;
- }
- /* first DH_KEY_LEN bytes are g^y from bob. Finish the dh handshake...*/
- assert(circ->build_state && circ->build_state->pending_final_cpath);
- hop = circ->build_state->pending_final_cpath;
- assert(hop->handshake_state);
- if (crypto_dh_compute_secret(hop->handshake_state, request, DH_KEY_LEN,
- keys, DIGEST_LEN+CPATH_KEY_MATERIAL_LEN)<0) {
- log_fn(LOG_WARN, "Couldn't complete DH handshake");
- goto err;
- }
- /* ... and set up cpath. */
- if (circuit_init_cpath_crypto(hop, keys+DIGEST_LEN, 0)<0)
- goto err;
- /* Check whether the digest is right... */
- if (memcmp(keys, request+DH_KEY_LEN, DIGEST_LEN)) {
- log_fn(LOG_WARN, "Incorrect digest of key material");
- goto err;
- }
- crypto_dh_free(hop->handshake_state);
- hop->handshake_state = NULL;
- /* All is well. Extend the circuit. */
- circ->purpose = CIRCUIT_PURPOSE_C_REND_JOINED;
- hop->state = CPATH_STATE_OPEN;
- /* set the windows to default. these are the windows
- * that alice thinks bob has.
- */
- hop->package_window = CIRCWINDOW_START;
- hop->deliver_window = CIRCWINDOW_START;
- onion_append_to_cpath(&circ->cpath, hop);
- circ->build_state->pending_final_cpath = NULL; /* prevent double-free */
- for(apconn = circ->p_streams; apconn; apconn = apconn->next_stream) {
- apconn->cpath_layer = circ->cpath->prev;
- /* now the last hop is different. be sure to send all the way. */
- if(connection_ap_handshake_send_begin(apconn, circ) < 0)
- return -1;
- }
- return 0;
- err:
- circuit_mark_for_close(circ);
- return -1;
- }
- /* Find all the apconns in state AP_CONN_STATE_RENDDESC_WAIT that
- * are waiting on query. If success==1, move them to the next state.
- * If success==0, fail them.
- */
- void rend_client_desc_fetched(char *query, int success) {
- connection_t **carray;
- connection_t *conn;
- int n, i;
- rend_cache_entry_t *entry;
- get_connection_array(&carray, &n);
- for (i = 0; i < n; ++i) {
- conn = carray[i];
- if (conn->type != CONN_TYPE_AP ||
- conn->state != AP_CONN_STATE_RENDDESC_WAIT)
- continue;
- if (rend_cmp_service_ids(conn->rend_query, query))
- continue;
- /* great, this guy was waiting */
- if(success ||
- rend_cache_lookup_entry(conn->rend_query, &entry) == 1) {
- /* either this fetch worked, or it failed but there was a
- * valid entry from before which we should reuse */
- log_fn(LOG_INFO,"Rend desc retrieved. Launching circuits.");
- conn->state = AP_CONN_STATE_CIRCUIT_WAIT;
- if (connection_ap_handshake_attach_circuit(conn) < 0) {
- /* it will never work */
- log_fn(LOG_WARN,"attaching to a rend circ failed. Closing conn.");
- connection_mark_for_close(conn,0);
- }
- } else { /* 404, or fetch didn't get that far */
- log_fn(LOG_WARN,"service id '%s' fetched failed, and not in cache. Closing conn.", query);
- connection_mark_for_close(conn,0);
- }
- }
- }
- int rend_cmp_service_ids(char *one, char *two) {
- return strcasecmp(one,two);
- }
- /* strdup a nickname for a random introduction
- * point of query. return NULL if error.
- */
- char *rend_client_get_random_intro(char *query) {
- int i;
- smartlist_t *sl;
- char *choice;
- char *nickname;
- rend_cache_entry_t *entry;
- if(rend_cache_lookup_entry(query, &entry) < 1) {
- log_fn(LOG_WARN,"query '%s' didn't have valid rend desc in cache. Failing.", query);
- return NULL;
- }
- sl = smartlist_create();
- /* add the intro point nicknames */
- for(i=0;i<entry->parsed->n_intro_points;i++)
- smartlist_add(sl,entry->parsed->intro_points[i]);
- choice = smartlist_choose(sl);
- if(!choice) {
- smartlist_free(sl);
- return NULL;
- }
- nickname = tor_strdup(choice);
- smartlist_free(sl);
- return nickname;
- }
- /* If address is of the form "y.onion" with a well-formed handle y,
- * then put a '\0' after y, lower-case it, and return 0.
- * Else return -1 and change nothing.
- */
- int rend_parse_rendezvous_address(char *address) {
- char *s;
- char query[REND_SERVICE_ID_LEN+1];
- s = strrchr(address,'.');
- if(!s) return -1; /* no dot */
- if (strcasecmp(s+1,"onion"))
- return -1; /* not .onion */
- *s = 0; /* null terminate it */
- if(strlcpy(query, address, REND_SERVICE_ID_LEN+1) >= REND_SERVICE_ID_LEN+1)
- goto failed;
- tor_strlower(query);
- if(rend_valid_service_id(query)) {
- tor_strlower(address);
- return 0; /* success */
- }
- failed:
- /* otherwise, return to previous state and return -1 */
- *s = '.';
- return -1;
- }
- /*
- Local Variables:
- mode:c
- indent-tabs-mode:nil
- c-basic-offset:2
- End:
- */
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