struct hash_if *hash;
uint32_t index; /* Index of this site */
+ uint32_t local_capabilities;
int32_t setup_retries; /* How many times to send setup packets */
int32_t setup_retry_interval; /* Initial timeout for setup packets */
int32_t wait_timeout; /* How long to wait if setup unsuccessful */
after this time, initiate a new
key exchange */
- uint8_t *setupsig; /* Expected signature of incoming MSG1 packets */
- int32_t setupsiglen; /* Allows us to discard packets quickly if
- they are not for us */
bool_t setup_priority; /* Do we have precedence if both sites emit
message 1 simultaneously? */
uint32_t log_events;
packet; we keep trying to continue the exchange, and have to
timeout before we can listen for another setup packet); perhaps
we should keep a list of 'bad' sources for setup packets. */
+ uint32_t remote_capabilities;
uint32_t setup_session_id;
transport_peers setup_peers;
uint8_t localN[NONCELEN]; /* Nonces for key exchange */
struct parsedname {
int32_t len;
uint8_t *name;
- int32_t extrainfo_len;
- uint8_t *extrainfo;
+ struct buffer_if extrainfo;
};
struct msg {
uint32_t source;
struct parsedname remote;
struct parsedname local;
+ uint32_t remote_capabilities;
uint8_t *nR;
uint8_t *nL;
int32_t pklen;
char *sig;
};
+struct xinfoadd {
+ int32_t lenpos, afternul;
+};
+static void append_string_xinfo_start(struct buffer_if *buf,
+ struct xinfoadd *xia,
+ const char *str)
+ /* Helps construct one of the names with additional info as found
+ * in MSG1..4. Call this function first, then append all the
+ * desired extra info (not including the nul byte) to the buffer,
+ * then call append_string_xinfo_done. */
+{
+ xia->lenpos = buf->size;
+ buf_append_string(buf,str);
+ buf_append_uint8(buf,0);
+ xia->afternul = buf->size;
+}
+static void append_string_xinfo_done(struct buffer_if *buf,
+ struct xinfoadd *xia)
+{
+ /* we just need to adjust the string length */
+ if (buf->size == xia->afternul) {
+ /* no extra info, strip the nul too */
+ buf_unappend_uint8(buf);
+ } else {
+ put_uint16(buf->start+xia->lenpos, buf->size-(xia->lenpos+2));
+ }
+}
+
/* Build any of msg1 to msg4. msg5 and msg6 are built from the inside
out using a transform of config data supplied by netlink */
static bool_t generate_msg(struct site *st, uint32_t type, cstring_t what)
(type==LABEL_MSG1?0:st->setup_session_id));
buf_append_uint32(&st->buffer,st->index);
buf_append_uint32(&st->buffer,type);
- buf_append_string(&st->buffer,st->localname);
+
+ struct xinfoadd xia;
+ append_string_xinfo_start(&st->buffer,&xia,st->localname);
+ if ((st->local_capabilities & CAPAB_EARLY) || (type != LABEL_MSG1)) {
+ buf_append_uint32(&st->buffer,st->local_capabilities);
+ }
+ append_string_xinfo_done(&st->buffer,&xia);
+
buf_append_string(&st->buffer,st->remotename);
memcpy(buf_append(&st->buffer,NONCELEN),st->localN,NONCELEN);
if (type==LABEL_MSG1) return True;
nm->name=buf_unprepend(msg,nm->len);
uint8_t *nul=memchr(nm->name,0,nm->len);
if (!nul) {
- nm->extrainfo_len=0;
- nm->extrainfo=0;
+ buffer_readonly_view(&nm->extrainfo,0,0);
} else {
- nm->extrainfo=nul+1;
- nm->extrainfo_len=msg->start-nm->extrainfo;
+ buffer_readonly_view(&nm->extrainfo, nul+1, msg->start-(nul+1));
nm->len=nul-nm->name;
}
return True;
m->source=buf_unprepend_uint32(msg);
CHECK_TYPE(msg,type);
if (!unpick_name(msg,&m->remote)) return False;
+ m->remote_capabilities=0;
+ if (m->remote.extrainfo.size) {
+ CHECK_AVAIL(&m->remote.extrainfo,4);
+ m->remote_capabilities=buf_unprepend_uint32(&m->remote.extrainfo);
+ }
if (!unpick_name(msg,&m->local)) return False;
CHECK_AVAIL(msg,NONCELEN);
m->nR=buf_unprepend(msg,NONCELEN);
*error="wrong remotely-generated nonce";
return False;
}
+ /* MSG3 has complicated rules about capabilities, which are
+ * handled in process_msg3. */
if (type==LABEL_MSG3) return True;
+ if (m->remote_capabilities!=st->remote_capabilities) {
+ *error="remote capabilities changed";
+ return False;
+ }
if (type==LABEL_MSG4) return True;
*error="unknown message type";
return False;
}
static bool_t process_msg1(struct site *st, struct buffer_if *msg1,
- const struct comm_addr *src)
+ const struct comm_addr *src, struct msg *m)
{
- struct msg m;
-
/* We've already determined we're in an appropriate state to
process an incoming MSG1, and that the MSG1 has correct values
of A and B. */
- if (!unpick_msg(st,LABEL_MSG1,msg1,&m)) return False;
-
transport_record_peer(st,&st->setup_peers,src,"msg1");
- st->setup_session_id=m.source;
- memcpy(st->remoteN,m.nR,NONCELEN);
+ st->setup_session_id=m->source;
+ st->remote_capabilities=m->remote_capabilities;
+ memcpy(st->remoteN,m->nR,NONCELEN);
return True;
}
return False;
}
st->setup_session_id=m.source;
+ st->remote_capabilities=m.remote_capabilities;
memcpy(st->remoteN,m.nR,NONCELEN);
return True;
}
slog(st,LOG_SEC,"msg3: %s",err);
return False;
}
+ uint32_t capab_adv_late = m.remote_capabilities
+ & ~st->remote_capabilities & CAPAB_EARLY;
+ if (capab_adv_late) {
+ slog(st,LOG_SEC,"msg3 impermissibly adds early capability flag(s)"
+ " %#"PRIx32" (was %#"PRIx32", now %#"PRIx32")",
+ capab_adv_late, st->remote_capabilities, m.remote_capabilities);
+ return False;
+ }
+ st->remote_capabilities|=m.remote_capabilities;
/* Check signature and store g^x mod m */
hash=safe_malloc(st->hash->len, "process_msg3");
static void dump_packet(struct site *st, struct buffer_if *buf,
const struct comm_addr *addr, bool_t incoming)
{
- uint32_t dest=ntohl(*(uint32_t *)buf->start);
- uint32_t source=ntohl(*(uint32_t *)(buf->start+4));
- uint32_t msgtype=ntohl(*(uint32_t *)(buf->start+8));
+ uint32_t dest=get_uint32(buf->start);
+ uint32_t source=get_uint32(buf->start+4);
+ uint32_t msgtype=get_uint32(buf->start+8);
if (st->log_events & LOG_DUMP)
slilog(st->log,M_DEBUG,"%s: %s: %08x<-%08x: %08x:",
initiate_key_setup(st,"outgoing packet");
}
+static bool_t named_for_us(struct site *st, const struct buffer_if *buf_in,
+ uint32_t type, struct msg *m)
+ /* For packets which are identified by the local and remote names.
+ * If it has our name and our peer's name in it it's for us. */
+{
+ struct buffer_if buf[1];
+ buffer_readonly_clone(buf,buf_in);
+ return unpick_msg(st,type,buf,m)
+ && name_matches(&m->remote,st->remotename)
+ && name_matches(&m->local,st->localname);
+}
+
/* This function is called by the communication device to deliver
packets from our peers. */
static bool_t site_incoming(void *sst, struct buffer_if *buf,
if (buf->size < 12) return False;
- uint32_t dest=ntohl(*(uint32_t *)buf->start);
-
- if (dest==0) {
- /* It could be for any site - it should have LABEL_MSG1 and
- might have our name and our peer's name in it */
- if (buf->size<(st->setupsiglen+8+NONCELEN)) return False;
- if (memcmp(buf->start+8,st->setupsig,st->setupsiglen)==0) {
- /* It's addressed to us. Decide what to do about it. */
- dump_packet(st,buf,source,True);
- if (st->state==SITE_RUN || st->state==SITE_RESOLVE ||
- st->state==SITE_WAIT) {
- /* We should definitely process it */
- if (process_msg1(st,buf,source)) {
- slog(st,LOG_SETUP_INIT,"key setup initiated by peer");
+ uint32_t dest=get_uint32(buf->start);
+ uint32_t msgtype=get_uint32(buf->start+8);
+ struct msg named_msg;
+
+ if (msgtype==LABEL_MSG1) {
+ if (!named_for_us(st,buf,msgtype,&named_msg))
+ return False;
+ /* It's a MSG1 addressed to us. Decide what to do about it. */
+ dump_packet(st,buf,source,True);
+ if (st->state==SITE_RUN || st->state==SITE_RESOLVE ||
+ st->state==SITE_WAIT) {
+ /* We should definitely process it */
+ if (process_msg1(st,buf,source,&named_msg)) {
+ slog(st,LOG_SETUP_INIT,"key setup initiated by peer");
+ enter_new_state(st,SITE_SENTMSG2);
+ } else {
+ slog(st,LOG_ERROR,"failed to process incoming msg1");
+ }
+ BUF_FREE(buf);
+ return True;
+ } else if (st->state==SITE_SENTMSG1) {
+ /* 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) {
+ BUF_FREE(buf);
+ slog(st,LOG_DUMP,"crossed msg1s; we are higher "
+ "priority => ignore incoming msg1");
+ return True;
+ } else {
+ slog(st,LOG_DUMP,"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 */
enter_new_state(st,SITE_SENTMSG2);
} else {
- slog(st,LOG_ERROR,"failed to process incoming msg1");
+ slog(st,LOG_ERROR,"failed to process an incoming "
+ "crossed msg1 (we have low priority)");
}
BUF_FREE(buf);
return True;
- } else if (st->state==SITE_SENTMSG1) {
- /* 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) {
- BUF_FREE(buf);
- slog(st,LOG_DUMP,"crossed msg1s; we are higher "
- "priority => ignore incoming msg1");
- return True;
- } else {
- slog(st,LOG_DUMP,"crossed msg1s; we are lower "
- "priority => use incoming msg1");
- if (process_msg1(st,buf,source)) {
- BUF_FREE(&st->buffer); /* Free our old message 1 */
- enter_new_state(st,SITE_SENTMSG2);
- } else {
- slog(st,LOG_ERROR,"failed to process an incoming "
- "crossed msg1 (we have low priority)");
- }
- BUF_FREE(buf);
- return True;
- }
}
- /* The message 1 was received at an unexpected stage of the
- key setup. XXX POLICY - what do we do? */
- slog(st,LOG_UNEXPECTED,"unexpected incoming message 1");
- BUF_FREE(buf);
- return True;
}
- return False; /* Not for us. */
+ /* The message 1 was received at an unexpected stage of the
+ key setup. XXX POLICY - what do we do? */
+ slog(st,LOG_UNEXPECTED,"unexpected incoming message 1");
+ BUF_FREE(buf);
+ return True;
}
if (dest==st->index) {
/* Explicitly addressed to us */
- uint32_t msgtype=ntohl(get_uint32(buf->start+8));
if (msgtype!=LABEL_MSG0) dump_packet(st,buf,source,True);
switch (msgtype) {
case LABEL_NAK:
assert(index_sequence < 0xffffffffUL);
st->index = ++index_sequence;
+ st->local_capabilities = 0;
st->netlink=find_cl_if(dict,"link",CL_NETLINK,True,"site",loc);
list_t *comms_cfg=dict_lookup(dict,"comm");
/* 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->setupsiglen=strlen(st->remotename)+strlen(st->localname)+8;
- st->setupsig=safe_malloc(st->setupsiglen,"site_apply");
- put_uint32(st->setupsig+0,LABEL_MSG1);
- put_uint16(st->setupsig+4,strlen(st->remotename));
- memcpy(&st->setupsig[6],st->remotename,strlen(st->remotename));
- put_uint16(st->setupsig+(6+strlen(st->remotename)),strlen(st->localname));
- memcpy(&st->setupsig[8+strlen(st->remotename)],st->localname,
- strlen(st->localname));
st->setup_priority=(strcmp(st->localname,st->remotename)>0);
buffer_new(&st->buffer,SETUP_BUFFER_LEN);
register_for_poll(st, site_beforepoll, site_afterpoll, 0, "site");
st->timeout=0;
+ st->remote_capabilities=0;
st->current.key_timeout=0;
st->auxiliary_key.key_timeout=0;
transport_peers_clear(st,&st->peers);
~ian / secnet.git / blobdiff