X-Git-Url: https://tinc-vpn.org/git/browse?a=blobdiff_plain;f=src%2Fprotocol_key.c;h=bbe0239df781379dcb028db0fac6b06869648591;hb=7a71d48009e03ff1143a6e1084803f456a27c849;hp=0e02c6ed33576ae9dee14c8bdd180a5174ed4134;hpb=68a20876d0c4a6c370064d78786dd9f2aa6273cb;p=tinc diff --git a/src/protocol_key.c b/src/protocol_key.c index 0e02c6ed..bbe0239d 100644 --- a/src/protocol_key.c +++ b/src/protocol_key.c @@ -24,13 +24,13 @@ #include "cipher.h" #include "connection.h" #include "crypto.h" -#include "ecdh.h" #include "logger.h" #include "net.h" #include "netutl.h" #include "node.h" #include "prf.h" #include "protocol.h" +#include "sptps.h" #include "utils.h" #include "xalloc.h" @@ -46,8 +46,20 @@ void send_key_changed(void) { for(node = connection_tree->head; node; node = node->next) { c = node->data; - if(c->status.active && c->node && c->node->status.reachable) - send_ans_key(c->node); + if(c->status.active && c->node && c->node->status.reachable) { + if(!c->node->status.sptps) + send_ans_key(c->node); + } + } + + /* Force key exchange for connections using SPTPS */ + + if(experimental) { + for(node = node_tree->head; node; node = node->next) { + node_t *n = node->data; + if(n->status.reachable && n->status.validkey && n->status.sptps) + sptps_force_kex(&n->sptps); + } } } @@ -72,8 +84,10 @@ bool key_changed_h(connection_t *c, const char *request) { return true; } - n->status.validkey = false; - n->last_req_key = 0; + if(!n->status.sptps) { + n->status.validkey = false; + n->last_req_key = 0; + } /* Tell the others */ @@ -83,11 +97,26 @@ bool key_changed_h(connection_t *c, const char *request) { return true; } +static bool send_initial_sptps_data(void *handle, uint8_t type, const char *data, size_t len) { + node_t *to = handle; + to->sptps.send_data = send_sptps_data; + char buf[len * 4 / 3 + 5]; + b64encode(data, buf, len); + return send_request(to->nexthop->connection, "%d %s %s %d %s", REQ_KEY, myself->name, to->name, REQ_KEY, buf); +} + bool send_req_key(node_t *to) { - if(experimental && OPTION_VERSION(to->options) >= 2) { - if(!node_read_ecdsa_public_key(to)) + if(to->status.sptps) { + if(!node_read_ecdsa_public_key(to)) { + logger(DEBUG_ALWAYS, LOG_DEBUG, "No ECDSA key known for %s (%s)", to->name, to->hostname); send_request(to->nexthop->connection, "%d %s %s %d", REQ_KEY, myself->name, to->name, REQ_PUBKEY); + return true; + } + char label[25 + strlen(myself->name) + strlen(to->name)]; + snprintf(label, sizeof label, "tinc UDP key expansion %s %s", myself->name, to->name); + return sptps_start(&to->sptps, to, true, true, myself->connection->ecdsa, to->ecdsa, label, sizeof label, send_initial_sptps_data, receive_sptps_record); } + return send_request(to->nexthop->connection, "%d %s %s", REQ_KEY, myself->name, to->name); } @@ -108,7 +137,7 @@ static bool req_key_ext_h(connection_t *c, const char *request, node_t *from, in return true; } - char pubkey[4096]; + char pubkey[MAX_STRING_SIZE]; if(sscanf(request, "%*d %*s %*s %*d " MAX_STRING, pubkey) != 1 || !ecdsa_set_base64_public_key(&from->ecdsa, pubkey)) { logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s): %s", "ANS_PUBKEY", from->name, from->hostname, "invalid pubkey"); return true; @@ -119,6 +148,30 @@ static bool req_key_ext_h(connection_t *c, const char *request, node_t *from, in return true; } + case REQ_KEY: { + if(!node_read_ecdsa_public_key(from)) { + logger(DEBUG_ALWAYS, LOG_DEBUG, "No ECDSA key known for %s (%s)", from->name, from->hostname); + send_request(from->nexthop->connection, "%d %s %s %d", REQ_KEY, myself->name, from->name, REQ_PUBKEY); + return true; + } + } + + case REQ_SPTPS: { + char buf[MAX_STRING_SIZE]; + if(sscanf(request, "%*d %*s %*s %*d " MAX_STRING, buf) != 1) { + logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s): %s", "REQ_KEY", from->name, from->hostname, "invalid SPTPS data"); + return true; + } + int len = b64decode(buf, buf, strlen(buf)); + + + char label[25 + strlen(from->name) + strlen(myself->name)]; + snprintf(label, sizeof label, "tinc UDP key expansion %s %s", from->name, myself->name); + sptps_start(&from->sptps, from, false, true, myself->connection->ecdsa, from->ecdsa, label, sizeof label, send_sptps_data, receive_sptps_record); + sptps_receive_data(&from->sptps, buf, len); + return true; + } + default: logger(DEBUG_ALWAYS, LOG_ERR, "Unknown extended REQ_KEY request from %s (%s): %s", from->name, from->hostname, request); return true; @@ -160,10 +213,12 @@ bool req_key_h(connection_t *c, const char *request) { /* Check if this key request is for us */ - if(to == myself) { /* Yes, send our own key back */ + if(to == myself) { /* Yes */ + /* Is this an extended REQ_KEY message? */ if(experimental && reqno) return req_key_ext_h(c, request, from, reqno); + /* No, just send our key back */ send_ans_key(from); } else { if(tunnelserver) @@ -181,31 +236,9 @@ bool req_key_h(connection_t *c, const char *request) { return true; } -bool send_ans_key_ecdh(node_t *to) { - int siglen = ecdsa_size(&myself->connection->ecdsa); - char key[(ECDH_SIZE + siglen) * 2 + 1]; - - if(!ecdh_generate_public(&to->ecdh, key)) - return false; - - if(!ecdsa_sign(&myself->connection->ecdsa, key, ECDH_SIZE, key + ECDH_SIZE)) - return false; - - b64encode(key, key, ECDH_SIZE + siglen); - - int result = send_request(to->nexthop->connection, "%d %s %s %s %d %d %zu %d", ANS_KEY, - myself->name, to->name, key, - cipher_get_nid(&myself->incipher), - digest_get_nid(&myself->indigest), - digest_length(&myself->indigest), - myself->incompression); - - return result; -} - bool send_ans_key(node_t *to) { - if(experimental && OPTION_VERSION(to->options) >= 2) - return send_ans_key_ecdh(to); + if(to->status.sptps) + abort(); size_t keylen = cipher_keylength(&myself->incipher); char key[keylen * 2 + 1]; @@ -225,11 +258,11 @@ bool send_ans_key(node_t *to) { to->received_seqno = 0; if(replaywin) memset(to->late, 0, replaywin); - return send_request(to->nexthop->connection, "%d %s %s %s %d %d %zu %d", ANS_KEY, + return send_request(to->nexthop->connection, "%d %s %s %s %d %d %d %d", ANS_KEY, myself->name, to->name, key, cipher_get_nid(&to->incipher), digest_get_nid(&to->indigest), - digest_length(&to->indigest), + (int)digest_length(&to->indigest), to->incompression); } @@ -296,6 +329,29 @@ bool ans_key_h(connection_t *c, const char *request) { return send_request(to->nexthop->connection, "%s", request); } + /* SPTPS or old-style key exchange? */ + + if(from->status.sptps) { + char buf[strlen(key)]; + int len = b64decode(key, buf, strlen(key)); + + if(!sptps_receive_data(&from->sptps, buf, len)) + logger(DEBUG_ALWAYS, LOG_ERR, "Error processing SPTPS data from %s (%s)", from->name, from->hostname); + + if(from->status.validkey) { + if(*address && *port) { + logger(DEBUG_PROTOCOL, LOG_DEBUG, "Using reflexive UDP address from %s: %s port %s", from->name, address, port); + sockaddr_t sa = str2sockaddr(address, port); + update_node_udp(from, &sa); + } + + if(from->options & OPTION_PMTU_DISCOVERY) + send_mtu_probe(from); + } + + return true; + } + /* Check and lookup cipher and digest algorithms */ if(!cipher_open_by_nid(&from->outcipher, cipher)) { @@ -320,99 +376,19 @@ bool ans_key_h(connection_t *c, const char *request) { from->outcompression = compression; - /* ECDH or old-style key exchange? */ - - if(experimental && OPTION_VERSION(from->options) >= 2) { - /* Check if we already have an ECDSA public key for this node. */ - - if(!node_read_ecdsa_public_key(from)) { - logger(DEBUG_ALWAYS, LOG_ERR, "No ECDSA public key known for %s (%s), cannot verify ECDH key exchange!", from->name, from->hostname); - return true; - } - - int siglen = ecdsa_size(&from->ecdsa); - int keylen = b64decode(key, key, sizeof key); - - if(keylen != ECDH_SIZE + siglen) { - logger(DEBUG_ALWAYS, LOG_ERR, "Node %s (%s) uses wrong keylength! %d != %d", from->name, from->hostname, keylen, ECDH_SIZE + siglen); - return true; - } - - if(ECDH_SHARED_SIZE < cipher_keylength(&from->outcipher)) { - logger(DEBUG_ALWAYS, LOG_ERR, "ECDH key too short for cipher of %s!", from->name); - return true; - } - - if(!ecdsa_verify(&from->ecdsa, key, ECDH_SIZE, key + ECDH_SIZE)) { - logger(DEBUG_ALWAYS, LOG_ERR, "Possible intruder %s (%s): %s", from->name, from->hostname, "invalid ECDSA signature"); - return true; - } - - if(!from->ecdh) { - if(!send_ans_key_ecdh(from)) - return true; - } - - char shared[ECDH_SHARED_SIZE * 2 + 1]; - - if(!ecdh_compute_shared(&from->ecdh, key, shared)) - return true; - - /* Update our crypto end */ - - size_t mykeylen = cipher_keylength(&myself->incipher); - size_t hiskeylen = cipher_keylength(&from->outcipher); - - char *mykey; - char *hiskey; - char *seed; - - if(strcmp(myself->name, from->name) < 0) { - mykey = key; - hiskey = key + mykeylen * 2; - xasprintf(&seed, "tinc UDP key expansion %s %s", myself->name, from->name); - } else { - mykey = key + hiskeylen * 2; - hiskey = key; - xasprintf(&seed, "tinc UDP key expansion %s %s", from->name, myself->name); - } - - if(!prf(shared, ECDH_SHARED_SIZE, seed, strlen(seed), key, hiskeylen * 2 + mykeylen * 2)) - return true; - - free(seed); - - cipher_open_by_nid(&from->incipher, cipher_get_nid(&myself->incipher)); - digest_open_by_nid(&from->indigest, digest_get_nid(&myself->indigest), digest_length(&myself->indigest)); - from->incompression = myself->incompression; + /* Process key */ - cipher_set_key(&from->incipher, mykey, false); - digest_set_key(&from->indigest, mykey + mykeylen, mykeylen); + keylen = hex2bin(key, key, sizeof key); - cipher_set_key(&from->outcipher, hiskey, true); - digest_set_key(&from->outdigest, hiskey + hiskeylen, hiskeylen); - - // Reset sequence number and late packet window - mykeyused = true; - from->received_seqno = 0; - if(replaywin) - memset(from->late, 0, replaywin); - - if(strcmp(myself->name, from->name) < 0) - memmove(key, key + mykeylen * 2, hiskeylen * 2); - } else { - keylen = hex2bin(key, key, sizeof key); - - if(keylen != cipher_keylength(&from->outcipher)) { - logger(DEBUG_ALWAYS, LOG_ERR, "Node %s (%s) uses wrong keylength!", from->name, from->hostname); - return true; - } + if(keylen != cipher_keylength(&from->outcipher)) { + logger(DEBUG_ALWAYS, LOG_ERR, "Node %s (%s) uses wrong keylength!", from->name, from->hostname); + return true; + } - /* Update our copy of the origin's packet key */ + /* Update our copy of the origin's packet key */ - cipher_set_key(&from->outcipher, key, true); - digest_set_key(&from->outdigest, key, keylen); - } + cipher_set_key(&from->outcipher, key, true); + digest_set_key(&from->outdigest, key, keylen); from->status.validkey = true; from->sent_seqno = 0;