// process an incoming handshake link_t link_receive_handshake(link_t link, lob_t inner) { uint32_t out, at, err; uint8_t csid = 0; lob_t outer = lob_linked(inner); if(!link || !inner || !outer) return LOG("bad args"); // inner/link must be validated by caller already, we just load if missing if(!link->key) { util_unhex(lob_get(inner, "csid"), 2, &csid); if(!link_load(link, csid, inner)) { lob_free(inner); return LOG("load key failed for %s %u %s",hashname_short(link->id),csid,util_hex(inner->body,inner->body_len,NULL)); } } if((err = e3x_exchange_verify(link->x,outer))) { lob_free(inner); return LOG("handshake verification fail: %d",err); } out = e3x_exchange_out(link->x,0); at = lob_get_uint(inner,"at"); link_t ready = link_up(link); // if bad at, always send current handshake if(e3x_exchange_in(link->x, at) < out) { LOG("old handshake: %s (%d,%d,%d)",lob_json(inner),at,out); link_sync(link); lob_free(inner); return link; } // try to sync ephemeral key if(!e3x_exchange_sync(link->x,outer)) { lob_free(inner); return LOG("sync failed"); } // we may need to re-sync if(out != e3x_exchange_out(link->x,0)) link_sync(link); // notify of ready state change if(!ready && link_up(link)) { LOG("link ready"); mesh_link(link->mesh, link); } link->handshake = lob_free(link->handshake); link->handshake = inner; return link; }
// 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; }