Merge branch 'master' into 1.1
[tinc] / src / protocol_key.c
index f2f317d..802f7ca 100644 (file)
 
 #include "system.h"
 
-#include <openssl/evp.h>
-#include <openssl/err.h>
-#include <openssl/rand.h>
-
-#include "avl_tree.h"
+#include "splay_tree.h"
+#include "cipher.h"
 #include "connection.h"
+#include "crypto.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"
 
 static bool mykeyused = false;
 
 void send_key_changed(void) {
-       avl_node_t *node;
+       splay_node_t *node;
        connection_t *c;
 
        send_request(everyone, "%d %x %s", KEY_CHANGED, rand(), myself->name);
@@ -46,72 +46,164 @@ 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);
+               }
        }
 }
 
-bool key_changed_h(connection_t *c) {
+bool key_changed_h(connection_t *c, const char *request) {
        char name[MAX_STRING_SIZE];
        node_t *n;
 
-       if(sscanf(c->buffer, "%*d %*x " MAX_STRING, name) != 1) {
-               logger(LOG_ERR, "Got bad %s from %s (%s)", "KEY_CHANGED",
+       if(sscanf(request, "%*d %*x " MAX_STRING, name) != 1) {
+               logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s)", "KEY_CHANGED",
                           c->name, c->hostname);
                return false;
        }
 
-       if(!check_id(name)) {
-               logger(LOG_ERR, "Got bad %s from %s (%s): %s", "KEY_CHANGED", c->name, c->hostname, "invalid name");
-               return false;
-       }
-
-       if(seen_request(c->buffer))
+       if(seen_request(request))
                return true;
 
        n = lookup_node(name);
 
        if(!n) {
-               logger(LOG_ERR, "Got %s from %s (%s) origin %s which does not exist",
+               logger(DEBUG_ALWAYS, LOG_ERR, "Got %s from %s (%s) origin %s which does not exist",
                           "KEY_CHANGED", c->name, c->hostname, name);
                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 */
 
        if(!tunnelserver)
-               forward_request(c);
+               forward_request(c, 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(to->status.sptps) {
+               if(!node_read_ecdsa_public_key(to)) {
+                       logger(DEBUG_PROTOCOL, 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);
+               sptps_stop(&to->sptps);
+               to->status.validkey = false;
+               to->incompression = myself->incompression;
+               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);
 }
 
-bool req_key_h(connection_t *c) {
+/* REQ_KEY is overloaded to allow arbitrary requests to be routed between two nodes. */
+
+static bool req_key_ext_h(connection_t *c, const char *request, node_t *from, int reqno) {
+       switch(reqno) {
+               case REQ_PUBKEY: {
+                       char *pubkey = ecdsa_get_base64_public_key(&myself->connection->ecdsa);
+                       send_request(from->nexthop->connection, "%d %s %s %d %s", REQ_KEY, myself->name, from->name, ANS_PUBKEY, pubkey);
+                       free(pubkey);
+                       return true;
+               }
+
+               case ANS_PUBKEY: {
+                       if(node_read_ecdsa_public_key(from)) {
+                               logger(DEBUG_PROTOCOL, LOG_WARNING, "Got ANS_PUBKEY from %s (%s) even though we already have his pubkey", from->name, from->hostname);
+                               return true;
+                       }
+
+                       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;
+                       }
+
+                       logger(DEBUG_PROTOCOL, LOG_INFO, "Learned ECDSA public key from %s (%s)", from->name, from->hostname);
+                       append_config_file(from->name, "ECDSAPublicKey", pubkey);
+                       return true;
+               }
+
+               case REQ_KEY: {
+                       if(!node_read_ecdsa_public_key(from)) {
+                               logger(DEBUG_PROTOCOL, 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_stop(&from->sptps);
+                       from->status.validkey = false;
+                       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;
+       }
+}
+
+bool req_key_h(connection_t *c, const char *request) {
        char from_name[MAX_STRING_SIZE];
        char to_name[MAX_STRING_SIZE];
        node_t *from, *to;
+       int reqno = 0;
 
-       if(sscanf(c->buffer, "%*d " MAX_STRING " " MAX_STRING, from_name, to_name) != 2) {
-               logger(LOG_ERR, "Got bad %s from %s (%s)", "REQ_KEY", c->name,
+       if(sscanf(request, "%*d " MAX_STRING " " MAX_STRING " %d", from_name, to_name, &reqno) < 2) {
+               logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s)", "REQ_KEY", c->name,
                           c->hostname);
                return false;
        }
 
        if(!check_id(from_name) || !check_id(to_name)) {
-               logger(LOG_ERR, "Got bad %s from %s (%s): %s", "REQ_KEY", c->name, c->hostname, "invalid name");
+               logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s): %s", "REQ_KEY", c->name, c->hostname, "invalid name");
                return false;
        }
 
        from = lookup_node(from_name);
 
        if(!from) {
-               logger(LOG_ERR, "Got %s from %s (%s) origin %s which does not exist in our connection list",
+               logger(DEBUG_ALWAYS, LOG_ERR, "Got %s from %s (%s) origin %s which does not exist in our connection list",
                           "REQ_KEY", c->name, c->hostname, from_name);
                return true;
        }
@@ -119,90 +211,92 @@ bool req_key_h(connection_t *c) {
        to = lookup_node(to_name);
 
        if(!to) {
-               logger(LOG_ERR, "Got %s from %s (%s) destination %s which does not exist in our connection list",
+               logger(DEBUG_ALWAYS, LOG_ERR, "Got %s from %s (%s) destination %s which does not exist in our connection list",
                           "REQ_KEY", c->name, c->hostname, to_name);
                return true;
        }
 
        /* 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)
                        return true;
 
                if(!to->status.reachable) {
-                       logger(LOG_WARNING, "Got %s from %s (%s) destination %s which is not reachable",
+                       logger(DEBUG_PROTOCOL, LOG_WARNING, "Got %s from %s (%s) destination %s which is not reachable",
                                "REQ_KEY", c->name, c->hostname, to_name);
                        return true;
                }
 
-               send_request(to->nexthop->connection, "%s", c->buffer);
+               send_request(to->nexthop->connection, "%s", request);
        }
 
        return true;
 }
 
 bool send_ans_key(node_t *to) {
-       // Set key parameters
-       to->incipher = myself->incipher;
-       to->inkeylength = myself->inkeylength;
-       to->indigest = myself->indigest;
-       to->inmaclength = myself->inmaclength;
+       if(to->status.sptps)
+               abort();
+
+       size_t keylen = cipher_keylength(&myself->incipher);
+       char key[keylen * 2 + 1];
+
+       cipher_open_by_nid(&to->incipher, cipher_get_nid(&myself->incipher));
+       digest_open_by_nid(&to->indigest, digest_get_nid(&myself->indigest), digest_length(&myself->indigest));
        to->incompression = myself->incompression;
 
-       // Allocate memory for key
-       to->inkey = xrealloc(to->inkey, to->inkeylength);
+       randomize(key, keylen);
+       cipher_set_key(&to->incipher, key, false);
+       digest_set_key(&to->indigest, key, keylen);
 
-       // Create a new key
-       RAND_pseudo_bytes((unsigned char *)to->inkey, to->inkeylength);
-       if(to->incipher)
-               EVP_DecryptInit_ex(&to->inctx, to->incipher, NULL, (unsigned char *)to->inkey, (unsigned char *)to->inkey + to->incipher->key_len);
+       bin2hex(key, key, keylen);
 
        // Reset sequence number and late packet window
        mykeyused = true;
        to->received_seqno = 0;
        if(replaywin) memset(to->late, 0, replaywin);
 
-       // Convert to hexadecimal and send
-       char key[2 * to->inkeylength + 1];
-       bin2hex(to->inkey, key, to->inkeylength);
-       key[to->inkeylength * 2] = '\0';
-
        return send_request(to->nexthop->connection, "%d %s %s %s %d %d %d %d", ANS_KEY,
-                       myself->name, to->name, key,
-                       to->incipher ? to->incipher->nid : 0,
-                       to->indigest ? to->indigest->type : 0, to->inmaclength,
-                       to->incompression);
+                                               myself->name, to->name, key,
+                                               cipher_get_nid(&to->incipher),
+                                               digest_get_nid(&to->indigest),
+                                               (int)digest_length(&to->indigest),
+                                               to->incompression);
 }
 
-bool ans_key_h(connection_t *c) {
+bool ans_key_h(connection_t *c, const char *request) {
        char from_name[MAX_STRING_SIZE];
        char to_name[MAX_STRING_SIZE];
        char key[MAX_STRING_SIZE];
-       char address[MAX_STRING_SIZE] = "";
-       char port[MAX_STRING_SIZE] = "";
-       int cipher, digest, maclength, compression;
+        char address[MAX_STRING_SIZE] = "";
+        char port[MAX_STRING_SIZE] = "";
+       int cipher, digest, maclength, compression, keylen;
        node_t *from, *to;
 
-       if(sscanf(c->buffer, "%*d "MAX_STRING" "MAX_STRING" "MAX_STRING" %d %d %d %d "MAX_STRING" "MAX_STRING,
+       if(sscanf(request, "%*d "MAX_STRING" "MAX_STRING" "MAX_STRING" %d %d %d %d "MAX_STRING" "MAX_STRING,
                from_name, to_name, key, &cipher, &digest, &maclength,
                &compression, address, port) < 7) {
-               logger(LOG_ERR, "Got bad %s from %s (%s)", "ANS_KEY", c->name,
+               logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s)", "ANS_KEY", c->name,
                           c->hostname);
                return false;
        }
 
        if(!check_id(from_name) || !check_id(to_name)) {
-               logger(LOG_ERR, "Got bad %s from %s (%s): %s", "ANS_KEY", c->name, c->hostname, "invalid name");
+               logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s): %s", "ANS_KEY", c->name, c->hostname, "invalid name");
                return false;
        }
 
        from = lookup_node(from_name);
 
        if(!from) {
-               logger(LOG_ERR, "Got %s from %s (%s) origin %s which does not exist in our connection list",
+               logger(DEBUG_ALWAYS, LOG_ERR, "Got %s from %s (%s) origin %s which does not exist in our connection list",
                           "ANS_KEY", c->name, c->hostname, from_name);
                return true;
        }
@@ -210,7 +304,7 @@ bool ans_key_h(connection_t *c) {
        to = lookup_node(to_name);
 
        if(!to) {
-               logger(LOG_ERR, "Got %s from %s (%s) destination %s which does not exist in our connection list",
+               logger(DEBUG_ALWAYS, LOG_ERR, "Got %s from %s (%s) destination %s which does not exist in our connection list",
                           "ANS_KEY", c->name, c->hostname, to_name);
                return true;
        }
@@ -222,99 +316,98 @@ bool ans_key_h(connection_t *c) {
                        return true;
 
                if(!to->status.reachable) {
-                       logger(LOG_WARNING, "Got %s from %s (%s) destination %s which is not reachable",
-                               "ANS_KEY", c->name, c->hostname, to_name);
+                       logger(DEBUG_ALWAYS, LOG_WARNING, "Got %s from %s (%s) destination %s which is not reachable",
+                                  "ANS_KEY", c->name, c->hostname, to_name);
                        return true;
                }
 
                if(!*address && from->address.sa.sa_family != AF_UNSPEC) {
                        char *address, *port;
-                       ifdebug(PROTOCOL) logger(LOG_DEBUG, "Appending reflexive UDP address to ANS_KEY from %s to %s", from->name, to->name);
+                       logger(DEBUG_PROTOCOL, LOG_DEBUG, "Appending reflexive UDP address to ANS_KEY from %s to %s", from->name, to->name);
                        sockaddr2str(&from->address, &address, &port);
-                       send_request(to->nexthop->connection, "%s %s %s", c->buffer, address, port);
+                       send_request(to->nexthop->connection, "%s %s %s", request, address, port);
                        free(address);
                        free(port);
                        return true;
                }
 
-               return send_request(to->nexthop->connection, "%s", c->buffer);
+               return send_request(to->nexthop->connection, "%s", request);
        }
 
        /* Don't use key material until every check has passed. */
        from->status.validkey = false;
 
-       /* Update our copy of the origin's packet key */
-       from->outkey = xrealloc(from->outkey, strlen(key) / 2);
-       from->outkeylength = strlen(key) / 2;
-       if(!hex2bin(key, from->outkey, from->outkeylength)) {
-               logger(LOG_ERR, "Got bad %s from %s(%s): %s", "ANS_KEY", from->name, from->hostname, "invalid key");
+       if(compression < 0 || compression > 11) {
+               logger(DEBUG_ALWAYS, LOG_ERR, "Node %s (%s) uses bogus compression level!", from->name, from->hostname);
                return true;
        }
 
-       /* Check and lookup cipher and digest algorithms */
+       from->outcompression = compression;
 
-       if(cipher) {
-               from->outcipher = EVP_get_cipherbynid(cipher);
+       /* SPTPS or old-style key exchange? */
 
-               if(!from->outcipher) {
-                       logger(LOG_ERR, "Node %s (%s) uses unknown cipher!", from->name,
-                                  from->hostname);
-                       return true;
-               }
+       if(from->status.sptps) {
+               char buf[strlen(key)];
+               int len = b64decode(key, buf, strlen(key));
 
-               if(from->outkeylength != from->outcipher->key_len + from->outcipher->iv_len) {
-                       logger(LOG_ERR, "Node %s (%s) uses wrong keylength!", from->name,
-                                  from->hostname);
-                       return true;
+               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);
                }
-       } else {
-               from->outcipher = NULL;
+
+               return true;
        }
 
-       from->outmaclength = maclength;
+       /* Check and lookup cipher and digest algorithms */
 
-       if(digest) {
-               from->outdigest = EVP_get_digestbynid(digest);
+       if(!cipher_open_by_nid(&from->outcipher, cipher)) {
+               logger(DEBUG_ALWAYS, LOG_ERR, "Node %s (%s) uses unknown cipher!", from->name, from->hostname);
+               return false;
+       }
 
-               if(!from->outdigest) {
-                       logger(LOG_ERR, "Node %s (%s) uses unknown digest!", from->name,
-                                  from->hostname);
-                       return true;
-               }
+       if(!digest_open_by_nid(&from->outdigest, digest, maclength)) {
+               logger(DEBUG_ALWAYS, LOG_ERR, "Node %s (%s) uses unknown digest!", from->name, from->hostname);
+               return false;
+       }
 
-               if(from->outmaclength > from->outdigest->md_size || from->outmaclength < 0) {
-                       logger(LOG_ERR, "Node %s (%s) uses bogus MAC length!",
-                                  from->name, from->hostname);
-                       return true;
-               }
-       } else {
-               from->outdigest = NULL;
+       if(maclength != digest_length(&from->outdigest)) {
+               logger(DEBUG_ALWAYS, LOG_ERR, "Node %s (%s) uses bogus MAC length!", from->name, from->hostname);
+               return false;
        }
 
-       if(compression < 0 || compression > 11) {
-               logger(LOG_ERR, "Node %s (%s) uses bogus compression level!", from->name, from->hostname);
+       /* Process key */
+
+       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;
        }
-       
-       from->outcompression = compression;
 
-       if(from->outcipher)
-               if(!EVP_EncryptInit_ex(&from->outctx, from->outcipher, NULL, (unsigned char *)from->outkey, (unsigned char *)from->outkey + from->outcipher->key_len)) {
-                       logger(LOG_ERR, "Error during initialisation of key from %s (%s): %s",
-                                       from->name, from->hostname, ERR_error_string(ERR_get_error(), NULL));
-                       return true;
-               }
+       /* Update our copy of the origin's packet key */
+
+       cipher_set_key(&from->outcipher, key, true);
+       digest_set_key(&from->outdigest, key, keylen);
 
        from->status.validkey = true;
        from->sent_seqno = 0;
 
        if(*address && *port) {
-               ifdebug(PROTOCOL) logger(LOG_DEBUG, "Using reflexive UDP address from %s: %s port %s", from->name, 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 && !from->mtuevent)
+       if(from->options & OPTION_PMTU_DISCOVERY)
                send_mtu_probe(from);
 
        return true;