lob_t local_decrypt(local_t local, lob_t outer)
{
uint8_t secret[crypto_box_BEFORENMBYTES];
lob_t inner, tmp;
// * `KEY` - 32 bytes, the sending exchange's ephemeral public key
// * `NONCE` - 24 bytes, randomly generated
// * `CIPHERTEXT` - the inner packet bytes encrypted using secretbox() using the `NONCE` as the nonce and the shared secret (derived from the recipients endpoint key and the included ephemeral key) as the key
// * `AUTH` - 16 bytes, the calculated onetimeauth(`KEY` + `INNER`, SHA256(`NONCE` + secret)) using the shared secret derived from both endpoint keys, the hashing is to minimize the chance that the same key input is ever used twice
if(outer->body_len <= (32+24+crypto_secretbox_MACBYTES+16)) return NULL;
tmp = lob_new();
if(!lob_body(tmp,NULL,outer->body_len-(32+24+crypto_secretbox_MACBYTES+16))) return lob_free(tmp);
// get the shared secret
crypto_box_beforenm(secret, outer->body, local->secret);
// decrypt the inner
if(crypto_secretbox_open_easy(tmp->body,
outer->body+32+24,
tmp->body_len+crypto_secretbox_MACBYTES,
outer->body+32,
secret) != 0) return lob_free(tmp);
// load inner packet
inner = lob_parse(tmp->body,tmp->body_len);
lob_free(tmp);
return inner;
}
lob_t local_decrypt(local_t local, lob_t outer)
{
uint8_t key[uECC_BYTES*2], shared[uECC_BYTES], iv[16], hash[32];
lob_t inner, tmp;
// * `KEY` - 21 bytes, the sender's ephemeral exchange public key in compressed format
// * `IV` - 4 bytes, a random but unique value determined by the sender
// * `INNER` - (minimum 21+2 bytes) the AES-128-CTR encrypted inner packet ciphertext
// * `HMAC` - 4 bytes, the calculated HMAC of all of the previous KEY+INNER bytes
if(outer->body_len <= (21+4+0+4)) return NULL;
tmp = lob_new();
if(!lob_body(tmp,NULL,outer->body_len-(4+21+4))) return lob_free(tmp);
// get the shared secret to create the iv+key for the open aes
uECC_decompress(outer->body,key);
if(!uECC_shared_secret(key, local->secret, shared)) return lob_free(tmp);
e3x_hash(shared,uECC_BYTES,hash);
fold1(hash,hash);
memset(iv,0,16);
memcpy(iv,outer->body+21,4);
// decrypt the inner
aes_128_ctr(hash,tmp->body_len,iv,outer->body+4+21,tmp->body);
// load inner packet
inner = lob_parse(tmp->body,tmp->body_len);
lob_free(tmp);
return inner;
}
lob_t ephemeral_decrypt(ephemeral_t ephem, lob_t outer)
{
crypto_secretbox_open_easy(outer->body+16+24,
outer->body+16+24,
outer->body_len-(16+24),
outer->body+16,
ephem->deckey);
return lob_parse(outer->body+16+24, outer->body_len-(16+24+crypto_secretbox_MACBYTES));
}
// process an incoming handshake
link_t link_receive_handshake(link_t link, lob_t inner, pipe_t pipe)
{
link_t ready;
uint32_t out, err;
seen_t seen;
uint8_t csid = 0;
char *hexid;
lob_t attached, outer = lob_linked(inner);
if(!link || !inner || !outer) return LOG("bad args");
hexid = lob_get(inner, "csid");
if(!lob_get(link->mesh->keys, hexid)) return LOG("unsupported csid %s",hexid);
util_unhex(hexid, 2, &csid);
attached = lob_parse(inner->body, inner->body_len);
if(!link->key && link_key(link->mesh, attached, csid) != link) return LOG("invalid/mismatch link handshake");
if((err = e3x_exchange_verify(link->x,outer))) return LOG("handshake verification fail: %d",err);
out = e3x_exchange_out(link->x,0);
ready = link_up(link);
// if bad at, always send current handshake
if(e3x_exchange_in(link->x, lob_get_uint(inner,"at")) < out)
{
LOG("old/bad at: %s (%d,%d,%d)",lob_json(inner),lob_get_int(inner,"at"),e3x_exchange_in(link->x,0),e3x_exchange_out(link->x,0));
// just reset pipe seen and call link_sync to resend handshake
for(seen = link->pipes;pipe && seen;seen = seen->next) if(seen->pipe == pipe) seen->at = 0;
lob_free(link_sync(link));
return NULL;
}
// trust/add this pipe
if(pipe) link_pipe(link,pipe);
// try to sync ephemeral key
if(!e3x_exchange_sync(link->x,outer)) return LOG("sync failed");
// we may need to re-sync
if(out != e3x_exchange_out(link->x,0)) lob_free(link_sync(link));
// notify of ready state change
if(!ready && link_up(link))
{
LOG("link ready");
mesh_link(link->mesh, link);
}
return link;
}
// get paths from host and query
lob_t util_uri_paths(lob_t uri)
{
uint32_t i;
uint16_t port;
uint8_t *buf;
size_t len;
char *key, *value;
lob_t paths, query = lob_linked(uri);
if(!query) return NULL;
paths = NULL;
// gen paths from host/port
if((port = lob_get_uint(uri,"port")))
{
key = lob_get(uri,"host");
paths = lob_chain(paths);
lob_set(paths,"type","upd4");
lob_set(paths,"ip",key);
lob_set_uint(paths,"port",port);
paths = lob_chain(paths);
lob_set(paths,"type","tcp4");
lob_set(paths,"ip",key);
lob_set_uint(paths,"port",port);
}
// loop through all keyval pairs to find paths
buf = NULL;
for(i=0;(key = lob_get_index(query,i));i+=2)
{
value = lob_get_index(query,i+1);
if(util_cmp(key,"paths") != 0 || !value) continue;
len = base32_decode_floor(strlen(value));
buf = util_reallocf(buf,len);
if(!buf) continue;
if(base32_decode(value,strlen(value),buf,len) < len) continue;
paths = lob_link(lob_parse(buf,len), paths);
}
free(buf);
return paths;
}
lob_t ephemeral_decrypt(ephemeral_t ephem, lob_t outer)
{
uint8_t iv[16], hmac[32];
memset(iv,0,16);
memcpy(iv,outer->body+16,4);
memcpy(hmac,ephem->deckey,16);
memcpy(hmac+16,iv,4);
// mac just the ciphertext
hmac_256(hmac,16+4,outer->body+16+4,outer->body_len-(4+16+4),hmac);
fold3(hmac,hmac);
if(util_ct_memcmp(hmac,outer->body+(outer->body_len-4),4) != 0) return LOG("hmac failed");
// decrypt in place
aes_128_ctr(ephem->deckey,outer->body_len-(16+4+4),iv,outer->body+16+4,outer->body+16+4);
// return parse attempt
return lob_parse(outer->body+16+4, outer->body_len-(16+4+4));
}
int main(int argc, char **argv)
{
lob_t packet;
packet = lob_new();
fail_unless(packet);
lob_free(packet);
uint8_t buf[1024];
char *hex = "001d7b2274797065223a2274657374222c22666f6f223a5b22626172225d7d616e792062696e61727921";
uint8_t len = strlen(hex)/2;
util_unhex(hex,strlen(hex),buf);
packet = lob_parse(buf,len);
fail_unless(packet);
fail_unless(lob_len(packet));
fail_unless(packet->head_len == 29);
fail_unless(packet->body_len == 11);
fail_unless(util_cmp(lob_get(packet,"type"),"test") == 0);
fail_unless(util_cmp(lob_get(packet,"foo"),"[\"bar\"]") == 0);
lob_free(packet);
packet = lob_new();
lob_set_base32(packet,"32",buf,len);
fail_unless(lob_get(packet,"32"));
fail_unless(strlen(lob_get(packet,"32")) == (base32_encode_length(len)-1));
lob_t bin = lob_get_base32(packet,"32");
fail_unless(bin);
fail_unless(bin->body_len == len);
lob_set(packet,"key","value");
fail_unless(lob_keys(packet) == 2);
// test sorting
lob_set(packet,"zz","value");
lob_set(packet,"a","value");
lob_set(packet,"z","value");
lob_sort(packet);
fail_unless(util_cmp(lob_get_index(packet,0),"32") == 0);
fail_unless(util_cmp(lob_get_index(packet,2),"a") == 0);
fail_unless(util_cmp(lob_get_index(packet,4),"key") == 0);
fail_unless(util_cmp(lob_get_index(packet,6),"z") == 0);
fail_unless(util_cmp(lob_get_index(packet,8),"zz") == 0);
lob_free(packet);
// minimal comparison test
lob_t a = lob_new();
lob_set(a,"foo","bar");
lob_t b = lob_new();
lob_set(b,"foo","bar");
fail_unless(lob_cmp(a,b) == 0);
lob_set(b,"bar","foo");
fail_unless(lob_cmp(a,b) != 0);
// lots of basic list testing
lob_t list = lob_new();
lob_t item = lob_new();
fail_unless(lob_push(list,item));
fail_unless(lob_pop(list) == item);
list = item->next;
fail_unless((list = lob_unshift(list,item)));
fail_unless(lob_shift(list) == item);
list = item->next;
fail_unless(lob_push(list,item));
fail_unless(list->next == item);
lob_t insert = lob_new();
fail_unless(lob_insert(list,list,insert));
fail_unless(list->next == insert);
fail_unless(insert->next == item);
fail_unless(lob_splice(list,insert));
fail_unless(list->next == item);
lob_t array = lob_array(list);
fail_unless(array);
fail_unless(util_cmp(lob_json(array),"[,]") == 0);
fail_unless(lob_freeall(list) == NULL);
// simple index testing
lob_t index = lob_new();
lob_t c1 = lob_new();
lob_set(c1,"id","c1");
lob_push(index,c1);
lob_t c2 = lob_new();
lob_set(c2,"id","c2");
lob_push(index,c2);
fail_unless(lob_match(index,"id","c1") == c1);
fail_unless(lob_match(index,"id","c2") == c2);
float f = 42.42;
lob_t ft = lob_new();
lob_head(ft,(uint8_t*)"{\"foo\":42.42}",13);
fail_unless(lob_get_float(ft,"foo") == f);
lob_set_float(ft,"bar2",f,2);
fail_unless(lob_get_float(ft,"bar2") == f);
lob_set_float(ft,"bar1",f,1);
fail_unless(lob_get_cmp(ft,"bar1","42.4") == 0);
lob_set_float(ft,"bar0",f,0);
fail_unless(lob_get_int(ft,"bar0") == 42);
LOG("floats %s",lob_json(ft));
return 0;
}
// the next frame of data in/out, if data NULL bool is just ready check
util_frames_t util_frames_inbox(util_frames_t frames, uint8_t *data, uint8_t *meta)
{
if(!frames) return LOG("bad args");
if(frames->err) return LOG("frame state error");
if(!data) return util_frames_await(frames);
// conveniences for code readability
uint8_t size = PAYLOAD(frames);
uint32_t hash1;
memcpy(&(hash1),data+size,4);
uint32_t hash2 = murmur4(data,size);
// LOG("frame sz %u hash rx %lu check %lu",size,hash1,hash2);
// meta frames are self contained
if(hash1 == hash2)
{
// LOG("meta frame %s",util_hex(data,size+4,NULL));
// if requested, copy in metadata block
if(meta) memcpy(meta,data+10,size-10);
// verify sender's last rx'd hash
uint32_t rxd;
memcpy(&rxd,data,4);
uint8_t *bin = lob_raw(frames->outbox);
uint32_t len = lob_len(frames->outbox);
uint32_t rxs = frames->outbase;
uint8_t i;
for(i = 0;i <= frames->out;i++)
{
// verify/reset to last rx'd frame
if(rxd == rxs)
{
frames->out = i;
break;
}
// handle tail hash correctly like sender
uint32_t at = i * size;
rxs ^= murmur4((bin+at), ((at+size) > len) ? (len - at) : size);
rxs += i;
}
if(rxd != rxs)
{
LOG("invalid received frame hash %lu check %lu",rxd,rxs);
frames->err = 1;
return NULL;
}
// advance full packet once confirmed
if((frames->out * size) > len)
{
frames->out = 0;
frames->outbase = rxd;
lob_t done = lob_shift(frames->outbox);
frames->outbox = done->next;
done->next = NULL;
lob_free(done);
}
// sender's last tx'd hash changes flush state
if(memcmp(data+4,&(frames->inlast),4) == 0)
{
frames->flush = 0;
}else{
frames->flush = 1;
LOG("flushing mismatch, last %lu",frames->inlast);
}
return frames;
}
// dedup, if identical to last received one
if(hash1 == frames->inlast) return frames;
// full data frames must match combined w/ previous
hash2 ^= frames->inlast;
hash2 += frames->in;
if(hash1 == hash2)
{
if(!util_frame_new(frames)) return LOG("OOM");
// append, update inlast, continue
memcpy(frames->cache->data,data,size);
frames->flush = 0;
frames->inlast = hash1;
// LOG("got data frame %lu",hash1);
return frames;
}
// check if it's a tail data frame
uint8_t tail = data[size-1];
if(tail >= size)
{
frames->flush = 1;
return LOG("invalid frame data length: %u %s",tail,util_hex(data+(size-4),8,NULL));
}
// hash must match
hash2 = murmur4(data,tail);
hash2 ^= frames->inlast;
hash2 += frames->in;
if(hash1 != hash2)
{
frames->flush = 1;
return LOG("invalid frame %u tail (%u) hash %lu != %lu last %lu",frames->in,tail,hash1,hash2,frames->inlast);
}
// process full packet w/ tail, update inlast, set flush
// LOG("got frame tail of %u",tail);
frames->flush = 1;
frames->inlast = hash1;
size_t tlen = (frames->in * size) + tail;
// TODO make a lob_new that creates space to prevent double-copy here
uint8_t *buf = malloc(tlen);
if(!buf) return LOG("OOM");
// copy in tail
memcpy(buf+(frames->in * size), data, tail);
// eat cached frames copying in reverse
util_frame_t frame = frames->cache;
while(frames->in && frame)
{
frames->in--;
memcpy(buf+(frames->in*size),frame->data,size);
frame = frame->prev;
}
frames->cache = util_frame_free(frames->cache);
lob_t packet = lob_parse(buf,tlen);
if(!packet) LOG("packet parsing failed: %s",util_hex(buf,tlen,NULL));
free(buf);
frames->inbox = lob_push(frames->inbox,packet);
return frames;
}
// process any unencrypted handshake packet
link_t mesh_receive_handshake(mesh_t mesh, lob_t handshake, pipe_t pipe)
{
uint32_t now;
hashname_t from;
link_t link;
if(!mesh || !handshake) return LOG("bad args");
if(!lob_get(handshake,"id"))
{
LOG("bad handshake, no id: %s",lob_json(handshake));
lob_free(handshake);
return NULL;
}
now = util_sys_seconds();
// normalize handshake
handshake->id = now; // save when we cached it
if(!lob_get(handshake,"type")) lob_set(handshake,"type","link"); // default to link type
if(!lob_get_uint(handshake,"at")) lob_set_uint(handshake,"at",now); // require an at
LOG("handshake at %d id %s",now,lob_get(handshake,"id"));
// validate/extend link handshakes immediately
if(util_cmp(lob_get(handshake,"type"),"link") == 0)
{
// get the csid
uint8_t csid = 0;
lob_t outer;
if((outer = lob_linked(handshake)))
{
csid = outer->head[0];
}else if(lob_get(handshake,"csid")){
util_unhex(lob_get(handshake,"csid"),2,&csid);
}
if(!csid)
{
LOG("bad link handshake, no csid: %s",lob_json(handshake));
lob_free(handshake);
return NULL;
}
char hexid[3] = {0};
util_hex(&csid, 1, hexid);
// get attached hashname
lob_t tmp = lob_parse(handshake->body, handshake->body_len);
from = hashname_vkey(tmp, csid);
if(!from)
{
LOG("bad link handshake, no hashname: %s",lob_json(handshake));
lob_free(tmp);
lob_free(handshake);
return NULL;
}
lob_set(handshake,"csid",hexid);
lob_set(handshake,"hashname",hashname_char(from));
lob_set_raw(handshake,hexid,2,"true",4); // intermediate format
lob_body(handshake, tmp->body, tmp->body_len); // re-attach as raw key
lob_free(tmp);
// short-cut, if it's a key from an existing link, pass it on
// TODO: using mesh_linked here is a stack issue during loopback peer test!
if((link = mesh_linkid(mesh,from))) return link_receive_handshake(link, handshake, pipe);
LOG("no link found for handshake from %s",hashname_char(from));
// extend the key json to make it compatible w/ normal patterns
tmp = lob_new();
lob_set_base32(tmp,hexid,handshake->body,handshake->body_len);
lob_set_raw(handshake,"keys",0,(char*)tmp->head,tmp->head_len);
lob_free(tmp);
// add the path if one
if(pipe && pipe->path)
{
char *paths = malloc(pipe->path->head_len+3);
sprintf(paths,"[%.*s]",(int)pipe->path->head_len,(char*)pipe->path->head);
lob_set_raw(handshake,"paths",0,paths,pipe->path->head_len+2);
free(paths);
}
}
// always add to the front of the cached list if needed in the future
mesh->cached = lob_unshift(mesh->cached, handshake);
// tell anyone listening about the newly discovered handshake
mesh_discover(mesh, handshake, pipe);
return NULL;
}
void ext_thtp(chan_t c)
{
lob_t p, buf, req, match, note;
char *path;
thtp_t t = thtp_get(c->s);
// incoming note as an answer
if((note = chan_notes(c)))
{
DEBUG_PRINTF("got note resp %.*s",note->json_len,note->json);
thtp_send(c,lob_linked(note));
lob_free(note);
return;
}
while((p = chan_pop(c)))
{
if(!c->arg)
{
c->arg = buf = p;
}else{
buf = c->arg;
lob_append(buf,p->body,p->body_len);
lob_free(p);
}
// for now we're processing whole-requests-at-once, to do streaming we can try parsing note->body for the headers anytime
if(c->ended) continue;
// parse the payload
p = lob_parse(buf->body,buf->body_len);
// this is a response, send it
if((note = lob_unlink(buf)))
{
lob_free(buf);
if(p)
{
DEBUG_PRINTF("got response %.*s for %.*s",p->json_len,p->json,note->json_len,note->json);
}
lob_link(note,p);
lob_set_str(note,"thtp","resp");
chan_reply(c,note);
chan_end(c,NULL);
return;
}
// this is an incoming request
lob_free(buf);
if(!p) return (void)chan_fail(c,"422");
req = p;
DEBUG_PRINTF("thtp req packet %.*s", req->json_len, req->json);
path = lob_get_str(req,"path");
match = xht_get(t->index,path);
if(!match) match = _thtp_glob(t,path);
if(!match)
{
chan_fail(c,"404");
lob_free(req);
return;
}
// built in response
if(lob_linked(match))
{
thtp_send(c,lob_linked(match));
lob_free(req);
return;
}
// attach and route request to a new note
note = lob_copy(match);
lob_link(note,req);
lob_set_str(note,"thtp","req");
if(chan_reply(c,note) == 0) return;
chan_fail(c,"500");
lob_free(req);
}
// optionally sends ack if needed
chan_ack(c);
}
