X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ian/git?a=blobdiff_plain;f=site.c;h=db1452394bf67b7f173cb8133dd2793c573f24eb;hb=b2de6bd2d9b5e9047a660e926c4adb17da54fc29;hp=dcac0baaf3428f20c8a97b83eb4d169954271119;hpb=5dfe538bae53c5dc90151043c7da782bd54cb44c;p=secnet.git diff --git a/site.c b/site.c index dcac0ba..db14523 100644 --- a/site.c +++ b/site.c @@ -6,7 +6,7 @@ * * secnet is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version d of the License, or + * the Free Software Foundation; either version 3 of the License, or * (at your option) any later version. * * secnet is distributed in the hope that it will be useful, but @@ -328,14 +328,14 @@ struct site { after this time, initiate a new key exchange */ - bool_t setup_priority; /* Do we have precedence if both sites emit - message 1 simultaneously? */ + bool_t our_name_later; /* our name > peer name */ uint32_t log_events; /* runtime information */ uint32_t state; uint64_t now; /* Most recently seen time */ bool_t allow_send_prod; + bool_t msg1_crossed_logged; int resolving_count; int resolving_n_results_all; int resolving_n_results_stored; @@ -534,8 +534,10 @@ struct msg { char *sig; }; -static void set_new_transform(struct site *st, char *pk) +static _Bool set_new_transform(struct site *st, char *pk) { + _Bool ok; + /* Make room for the shared key */ st->sharedsecretlen=st->chosen_transform->keylen?:st->dh->ceil_len; assert(st->sharedsecretlen); @@ -553,15 +555,18 @@ static void set_new_transform(struct site *st, char *pk) /* Set up the transform */ struct transform_if *generator=st->chosen_transform; struct transform_inst_if *generated=generator->create(generator->st); - generated->setkey(generated->st,st->sharedsecret, - st->sharedsecretlen,st->setup_priority); + ok = generated->setkey(generated->st,st->sharedsecret, + st->sharedsecretlen,st->our_name_later); + dispose_transform(&st->new_transform); + if (!ok) return False; st->new_transform=generated; slog(st,LOG_SETUP_INIT,"key exchange negotiated transform" " %d (capabilities ours=%#"PRIx32" theirs=%#"PRIx32")", st->chosen_transform->capab_transformnum, st->local_capabilities, st->remote_capabilities); + return True; } struct xinfoadd { @@ -713,6 +718,13 @@ static bool_t unpick_msg(struct site *st, uint32_t type, CHECK_AVAIL(msg,m->siglen); m->sig=buf_unprepend(msg,m->siglen); CHECK_EMPTY(msg); + + /* In `process_msg3_msg4' below, we assume that we can write a nul + * terminator following the signature. Make sure there's enough space. + */ + if (msg->start >= msg->base + msg->alloclen) + return False; + return True; } @@ -846,7 +858,7 @@ static bool_t process_msg3_msg4(struct site *st, struct msg *m) hst=st->hash->init(); st->hash->update(hst,m->hashstart,m->hashlen); st->hash->final(hst,hash); - /* Terminate signature with a '0' - cheating, but should be ok */ + /* Terminate signature with a '0' - already checked that this will fit */ m->sig[m->siglen]=0; if (!st->pubkey->check(st->pubkey->st,hash,st->hash->len,m->sig)) { slog(st,LOG_SEC,"msg3/msg4 signature failed check!"); @@ -905,7 +917,7 @@ static bool_t process_msg3(struct site *st, struct buffer_if *msg3, st->random->generate(st->random->st,st->dh->len,st->dhsecret); /* Generate the shared key and set up the transform */ - set_new_transform(st,m.pk); + if (!set_new_transform(st,m.pk)) return False; return True; } @@ -936,7 +948,7 @@ static bool_t process_msg4(struct site *st, struct buffer_if *msg4, m.pk[m.pklen]=0; /* Generate the shared key and set up the transform */ - set_new_transform(st,m.pk); + if (!set_new_transform(st,m.pk)) return False; return True; } @@ -1131,7 +1143,8 @@ static bool_t decrypt_msg0(struct site *st, struct buffer_if *msg0, skew: slog(st,LOG_DROP,"transform: %s (merely skew)",transform_err); - return False; + assert(problem); + return problem; } static bool_t process_msg0(struct site *st, struct buffer_if *msg0, @@ -1449,7 +1462,7 @@ static void enter_state_run(struct site *st) FILLZERO(st->remoteN); dispose_transform(&st->new_transform); memset(st->dhsecret,0,st->dh->len); - memset(st->sharedsecret,0,st->sharedsecretlen); + if (st->sharedsecret) memset(st->sharedsecret,0,st->sharedsecretlen); set_link_quality(st); if (st->keepalive && !current_valid(st)) @@ -1512,6 +1525,7 @@ static bool_t enter_new_state(struct site *st, uint32_t next) case SITE_SENTMSG1: state_assert(st,st->state==SITE_RUN || st->state==SITE_RESOLVE); gen=generate_msg1; + st->msg1_crossed_logged = False; break; case SITE_SENTMSG2: state_assert(st,st->state==SITE_RUN || st->state==SITE_RESOLVE || @@ -1741,6 +1755,15 @@ static bool_t named_for_us(struct site *st, const struct buffer_if *buf_in, && name_matches(&m->local,st->localname); } +static bool_t we_have_priority(struct site *st, const struct msg *m) { + if ((st->local_capabilities & m->remote_capabilities) + && CAPAB_PRIORITY_MOBILE) { + if (st->local_mobile) return True; + if (st-> peer_mobile) return False; + } + return st->our_name_later; +} + /* This function is called by the communication device to deliver packets from our peers. It should return True if the packet is recognised as being for @@ -1782,13 +1805,14 @@ static bool_t site_incoming(void *sst, struct buffer_if *buf, /* We've just sent a message 1! They may have crossed on the wire. If we have priority then we ignore the incoming one, otherwise we process it as usual. */ - if (st->setup_priority) { + if (we_have_priority(st,&named_msg)) { BUF_FREE(buf); - slog(st,LOG_DUMP,"crossed msg1s; we are higher " - "priority => ignore incoming msg1"); + if (!st->msg1_crossed_logged++) + slog(st,LOG_SETUP_INIT,"crossed msg1s; we are higher " + "priority => ignore incoming msg1"); return True; } else { - slog(st,LOG_DUMP,"crossed msg1s; we are lower " + slog(st,LOG_SETUP_INIT,"crossed msg1s; we are lower " "priority => use incoming msg1"); if (process_msg1(st,buf,source,&named_msg)) { BUF_FREE(&st->buffer); /* Free our old message 1 */ @@ -2114,7 +2138,7 @@ static list_t *site_apply(closure_t *self, struct cloc loc, dict_t *context, /* The information we expect to see in incoming messages of type 1 */ /* fixme: lots of unchecked overflows here, but the results are only corrupted packets rather than undefined behaviour */ - st->setup_priority=(strcmp(st->localname,st->remotename)>0); + st->our_name_later=(strcmp(st->localname,st->remotename)>0); buffer_new(&st->buffer,SETUP_BUFFER_LEN); @@ -2146,6 +2170,9 @@ static list_t *site_apply(closure_t *self, struct cloc loc, dict_t *context, st->local_capabilities |= capbit; } + if (st->local_mobile || st->peer_mobile) + st->local_capabilities |= CAPAB_PRIORITY_MOBILE; + /* We need to register the remote networks with the netlink device */ uint32_t netlink_mtu; /* local virtual interface mtu */ st->netlink->reg(st->netlink->st, site_outgoing, st, &netlink_mtu); @@ -2249,11 +2276,18 @@ static void transport_record_peers(struct site *st, transport_peers *peers, * * Caller must first call transport_peers_expire. */ - if (naddrs==1 && peers->npeers>=1 && - comm_addr_equal(&addrs[0], &peers->peers[0].addr)) { - /* optimisation, also avoids debug for trivial updates */ - peers->peers[0].last = *tv_now; - return; + if (naddrs==1) { + /* avoids debug for uninteresting updates */ + int i; + for (i=0; inpeers; i++) { + if (comm_addr_equal(&addrs[0], &peers->peers[i].addr)) { + memmove(peers->peers+1, peers->peers, + sizeof(peers->peers[0]) * i); + peers->peers[0].addr = addrs[0]; + peers->peers[0].last = *tv_now; + return; + } + } } int old_npeers=peers->npeers;