diff options
Diffstat (limited to 'src/or/router.c')
| -rw-r--r-- | src/or/router.c | 224 |
1 files changed, 219 insertions, 5 deletions
diff --git a/src/or/router.c b/src/or/router.c index c7380cb444..29011c2536 100644 --- a/src/or/router.c +++ b/src/or/router.c @@ -13,6 +13,7 @@ #include "config.h" #include "connection.h" #include "control.h" +#include "crypto_curve25519.h" #include "directory.h" #include "dirserv.h" #include "dns.h" @@ -54,6 +55,13 @@ static crypto_pk_t *onionkey=NULL; /** Previous private onionskin decryption key: used to decode CREATE cells * generated by clients that have an older version of our descriptor. */ static crypto_pk_t *lastonionkey=NULL; +#ifdef CURVE25519_ENABLED +/** Current private ntor secret key: used to perform the ntor handshake. */ +static curve25519_keypair_t curve25519_onion_key; +/** Previous private ntor secret key: used to perform the ntor handshake + * with clients that have an older version of our descriptor. */ +static curve25519_keypair_t last_curve25519_onion_key; +#endif /** Private server "identity key": used to sign directory info and TLS * certificates. Never changes. */ static crypto_pk_t *server_identitykey=NULL; @@ -126,6 +134,55 @@ dup_onion_keys(crypto_pk_t **key, crypto_pk_t **last) tor_mutex_release(key_lock); } +#ifdef CURVE25519_ENABLED +/** Return the current secret onion key for the ntor handshake. Must only + * be called from the main thread. */ +static const curve25519_keypair_t * +get_current_curve25519_keypair(void) +{ + return &curve25519_onion_key; +} +/** Return a map from KEYID (the key itself) to keypairs for use in the ntor + * handshake. Must only be called from the main thread. */ +di_digest256_map_t * +construct_ntor_key_map(void) +{ + di_digest256_map_t *m = NULL; + + dimap_add_entry(&m, + curve25519_onion_key.pubkey.public_key, + tor_memdup(&curve25519_onion_key, + sizeof(curve25519_keypair_t))); + if (!tor_mem_is_zero((const char*) + last_curve25519_onion_key.pubkey.public_key, + CURVE25519_PUBKEY_LEN)) { + dimap_add_entry(&m, + last_curve25519_onion_key.pubkey.public_key, + tor_memdup(&last_curve25519_onion_key, + sizeof(curve25519_keypair_t))); + } + + return m; +} +/** Helper used to deallocate a di_digest256_map_t returned by + * construct_ntor_key_map. */ +static void +ntor_key_map_free_helper(void *arg) +{ + curve25519_keypair_t *k = arg; + memwipe(k, 0, sizeof(*k)); + tor_free(k); +} +/** Release all storage from a keymap returned by construct_ntor_key_map. */ +void +ntor_key_map_free(di_digest256_map_t *map) +{ + if (!map) + return; + dimap_free(map, ntor_key_map_free_helper); +} +#endif + /** Return the time when the onion key was last set. This is either the time * when the process launched, or the time of the most recent key rotation since * the process launched. @@ -253,11 +310,18 @@ void rotate_onion_key(void) { char *fname, *fname_prev; - crypto_pk_t *prkey; + crypto_pk_t *prkey = NULL; or_state_t *state = get_or_state(); +#ifdef CURVE25519_ENABLED + curve25519_keypair_t new_curve25519_keypair; +#endif time_t now; fname = get_datadir_fname2("keys", "secret_onion_key"); fname_prev = get_datadir_fname2("keys", "secret_onion_key.old"); + if (file_status(fname) == FN_FILE) { + if (replace_file(fname, fname_prev)) + goto error; + } if (!(prkey = crypto_pk_new())) { log_err(LD_GENERAL,"Error constructing rotated onion key"); goto error; @@ -266,19 +330,38 @@ rotate_onion_key(void) log_err(LD_BUG,"Error generating onion key"); goto error; } + if (crypto_pk_write_private_key_to_filename(prkey, fname)) { + log_err(LD_FS,"Couldn't write generated onion key to \"%s\".", fname); + goto error; + } +#ifdef CURVE25519_ENABLED + tor_free(fname); + tor_free(fname_prev); + fname = get_datadir_fname2("keys", "secret_onion_key_ntor"); + fname_prev = get_datadir_fname2("keys", "secret_onion_key_ntor.old"); + if (curve25519_keypair_generate(&new_curve25519_keypair, 1) < 0) + goto error; if (file_status(fname) == FN_FILE) { if (replace_file(fname, fname_prev)) goto error; } - if (crypto_pk_write_private_key_to_filename(prkey, fname)) { - log_err(LD_FS,"Couldn't write generated onion key to \"%s\".", fname); + if (curve25519_keypair_write_to_file(&new_curve25519_keypair, fname, + "onion") < 0) { + log_err(LD_FS,"Couldn't write curve25519 onion key to \"%s\".",fname); goto error; } +#endif log_info(LD_GENERAL, "Rotating onion key"); tor_mutex_acquire(key_lock); crypto_pk_free(lastonionkey); lastonionkey = onionkey; onionkey = prkey; +#ifdef CURVE25519_ENABLED + memcpy(&last_curve25519_onion_key, &curve25519_onion_key, + sizeof(curve25519_keypair_t)); + memcpy(&curve25519_onion_key, &new_curve25519_keypair, + sizeof(curve25519_keypair_t)); +#endif now = time(NULL); state->LastRotatedOnionKey = onionkey_set_at = now; tor_mutex_release(key_lock); @@ -290,6 +373,9 @@ rotate_onion_key(void) if (prkey) crypto_pk_free(prkey); done: +#ifdef CURVE25519_ENABLED + memwipe(&new_curve25519_keypair, 0, sizeof(new_curve25519_keypair)); +#endif tor_free(fname); tor_free(fname_prev); } @@ -363,6 +449,77 @@ init_key_from_file(const char *fname, int generate, int severity) return NULL; } +#ifdef CURVE25519_ENABLED +/** Load a curve25519 keypair from the file <b>fname</b>, writing it into + * <b>keys_out</b>. If the file isn't found and <b>generate</b> is true, + * create a new keypair and write it into the file. If there are errors, log + * them at level <b>severity</b>. Generate files using <b>tag</b> in their + * ASCII wrapper. */ +static int +init_curve25519_keypair_from_file(curve25519_keypair_t *keys_out, + const char *fname, + int generate, + int severity, + const char *tag) +{ + switch (file_status(fname)) { + case FN_DIR: + case FN_ERROR: + log(severity, LD_FS,"Can't read key from \"%s\"", fname); + goto error; + case FN_NOENT: + if (generate) { + if (!have_lockfile()) { + if (try_locking(get_options(), 0)<0) { + /* Make sure that --list-fingerprint only creates new keys + * if there is no possibility for a deadlock. */ + log(severity, LD_FS, "Another Tor process has locked \"%s\". Not " + "writing any new keys.", fname); + /*XXXX The 'other process' might make a key in a second or two; + * maybe we should wait for it. */ + goto error; + } + } + log_info(LD_GENERAL, "No key found in \"%s\"; generating fresh key.", + fname); + if (curve25519_keypair_generate(keys_out, 1) < 0) + goto error; + if (curve25519_keypair_write_to_file(keys_out, fname, tag)<0) { + log(severity, LD_FS, + "Couldn't write generated key to \"%s\".", fname); + memset(keys_out, 0, sizeof(*keys_out)); + goto error; + } + } else { + log_info(LD_GENERAL, "No key found in \"%s\"", fname); + } + return 0; + case FN_FILE: + { + char *tag_in=NULL; + if (curve25519_keypair_read_from_file(keys_out, &tag_in, fname) < 0) { + log(severity, LD_GENERAL,"Error loading private key."); + tor_free(tag_in); + goto error; + } + if (!tag_in || strcmp(tag_in, tag)) { + log(severity, LD_GENERAL,"Unexpected tag %s on private key.", + escaped(tag_in)); + tor_free(tag_in); + goto error; + } + tor_free(tag_in); + return 0; + } + default: + tor_assert(0); + } + + error: + return -1; +} +#endif + /** Try to load the vote-signing private key and certificate for being a v3 * directory authority, and make sure they match. If <b>legacy</b>, load a * legacy key/cert set for emergency key migration; otherwise load the regular @@ -641,12 +798,35 @@ init_keys(void) keydir = get_datadir_fname2("keys", "secret_onion_key.old"); if (!lastonionkey && file_status(keydir) == FN_FILE) { - prkey = init_key_from_file(keydir, 1, LOG_ERR); + prkey = init_key_from_file(keydir, 1, LOG_ERR); /* XXXX Why 1? */ if (prkey) lastonionkey = prkey; } tor_free(keydir); +#ifdef CURVE25519_ENABLED + { + /* 2b. Load curve25519 onion keys. */ + int r; + keydir = get_datadir_fname2("keys", "secret_onion_key_ntor"); + r = init_curve25519_keypair_from_file(&curve25519_onion_key, + keydir, 1, LOG_ERR, "onion"); + tor_free(keydir); + if (r<0) + return -1; + + keydir = get_datadir_fname2("keys", "secret_onion_key_ntor.old"); + if (tor_mem_is_zero((const char *) + last_curve25519_onion_key.pubkey.public_key, + CURVE25519_PUBKEY_LEN) && + file_status(keydir) == FN_FILE) { + init_curve25519_keypair_from_file(&last_curve25519_onion_key, + keydir, 0, LOG_ERR, "onion"); + } + tor_free(keydir); + } +#endif + /* 3. Initialize link key and TLS context. */ if (router_initialize_tls_context() < 0) { log_err(LD_GENERAL,"Error initializing TLS context"); @@ -905,7 +1085,8 @@ extend_info_from_router(const routerinfo_t *r) router_get_prim_orport(r, &ap); return extend_info_new(r->nickname, r->cache_info.identity_digest, - r->onion_pkey, &ap.addr, ap.port); + r->onion_pkey, r->onion_curve25519_pkey, + &ap.addr, ap.port); } /** Some time has passed, or we just got new directory information. @@ -1432,6 +1613,13 @@ router_digest_is_me(const char *digest) tor_memeq(server_identitykey_digest, digest, DIGEST_LEN)); } +/** Return my identity digest. */ +const uint8_t * +router_get_my_id_digest(void) +{ + return (const uint8_t *)server_identitykey_digest; +} + /** Return true iff I'm a server and <b>digest</b> is equal to * my identity digest. */ int @@ -1578,6 +1766,11 @@ router_rebuild_descriptor(int force) ri->cache_info.published_on = time(NULL); ri->onion_pkey = crypto_pk_dup_key(get_onion_key()); /* must invoke from * main thread */ +#ifdef CURVE25519_ENABLED + ri->onion_curve25519_pkey = + tor_memdup(&get_current_curve25519_keypair()->pubkey, + sizeof(curve25519_public_key_t)); +#endif /* For now, at most one IPv6 or-address is being advertised. */ { @@ -2158,6 +2351,22 @@ router_dump_router_to_string(char *s, size_t maxlen, routerinfo_t *router, written += result; } +#ifdef CURVE25519_ENABLED + if (router->onion_curve25519_pkey) { + char kbuf[128]; + base64_encode(kbuf, sizeof(kbuf), + (const char *)router->onion_curve25519_pkey->public_key, + CURVE25519_PUBKEY_LEN); + result = tor_snprintf(s+written,maxlen-written, "ntor-onion-key %s", + kbuf); + if (result<0) { + log_warn(LD_BUG,"descriptor snprintf ran out of room!"); + return -1; + } + written += result; + } +#endif + /* Write the exit policy to the end of 's'. */ if (!router->exit_policy || !smartlist_len(router->exit_policy)) { strlcat(s+written, "reject *:*\n", maxlen-written); @@ -2806,6 +3015,11 @@ router_free_all(void) crypto_pk_free(legacy_signing_key); authority_cert_free(legacy_key_certificate); +#ifdef CURVE25519_ENABLED + memwipe(&curve25519_onion_key, 0, sizeof(curve25519_onion_key)); + memwipe(&last_curve25519_onion_key, 0, sizeof(last_curve25519_onion_key)); +#endif + if (warned_nonexistent_family) { SMARTLIST_FOREACH(warned_nonexistent_family, char *, cp, tor_free(cp)); smartlist_free(warned_nonexistent_family); |