Use AES in CTR mode instead of OFB mode for meta-connections.
[oweals/tinc.git] / src / net_setup.c
index e1d9f2759e8758e583aee0a30e852515e47e8f00..eeeefdf6baaa982f6c9a1ede4ba33b2c50ba2035 100644 (file)
@@ -1,7 +1,7 @@
 /*
     net_setup.c -- Setup.
     Copyright (C) 1998-2005 Ivo Timmermans,
-                  2000-2013 Guus Sliepen <guus@tinc-vpn.org>
+                  2000-2016 Guus Sliepen <guus@tinc-vpn.org>
                   2006      Scott Lamb <slamb@slamb.org>
                   2010      Brandon Black <blblack@gmail.com>
 
@@ -39,6 +39,7 @@
 #include "netutl.h"
 #include "process.h"
 #include "protocol.h"
+#include "proxy.h"
 #include "route.h"
 #include "subnet.h"
 #include "utils.h"
 char *myport;
 devops_t devops;
 
-char *proxyhost;
-char *proxyport;
-char *proxyuser;
-char *proxypass;
-proxytype_t proxytype;
+#ifndef HAVE_RSA_SET0_KEY
+int RSA_set0_key(RSA *r, BIGNUM *n, BIGNUM *e, BIGNUM *d) {
+       BN_free(r->n); r->n = n;
+       BN_free(r->e); r->e = e;
+       BN_free(r->d); r->d = d;
+       return 1;
+}
+#endif
 
 bool read_rsa_public_key(connection_t *c) {
        FILE *fp;
        char *pubname;
        char *hcfname;
        char *key;
+       BIGNUM *n = NULL;
+       BIGNUM *e = NULL;
 
        if(!c->rsa_key) {
                c->rsa_key = RSA_new();
@@ -67,12 +73,19 @@ bool read_rsa_public_key(connection_t *c) {
        /* First, check for simple PublicKey statement */
 
        if(get_config_string(lookup_config(c->config_tree, "PublicKey"), &key)) {
-               if(BN_hex2bn(&c->rsa_key->n, key) != strlen(key)) {
+               if(BN_hex2bn(&n, key) != strlen(key)) {
+                       free(key);
                        logger(LOG_ERR, "Invalid PublicKey for %s!", c->name);
                        return false;
                }
-               BN_hex2bn(&c->rsa_key->e, "FFFF");
                free(key);
+               BN_hex2bn(&e, "FFFF");
+               if(!n || !e || RSA_set0_key(c->rsa_key, n, e, NULL) != 1) {
+                       BN_free(e);
+                       BN_free(n);
+                       logger(LOG_ERR, "RSA_set0_key() failed with PublicKey for %s!", c->name);
+                       return false;
+               }
                return true;
        }
 
@@ -163,25 +176,39 @@ bool read_rsa_public_key(connection_t *c) {
 static bool read_rsa_private_key(void) {
        FILE *fp;
        char *fname, *key, *pubkey;
+       BIGNUM *n = NULL;
+       BIGNUM *e = NULL;
+       BIGNUM *d = NULL;
 
        if(get_config_string(lookup_config(config_tree, "PrivateKey"), &key)) {
-               if(!get_config_string(lookup_config(config_tree, "PublicKey"), &pubkey)) {
-                       logger(LOG_ERR, "PrivateKey used but no PublicKey found!");
-                       return false;
-               }
                myself->connection->rsa_key = RSA_new();
 //             RSA_blinding_on(myself->connection->rsa_key, NULL);
-               if(BN_hex2bn(&myself->connection->rsa_key->d, key) != strlen(key)) {
+               if(BN_hex2bn(&d, key) != strlen(key)) {
                        logger(LOG_ERR, "Invalid PrivateKey for myself!");
+                       free(key);
                        return false;
                }
-               if(BN_hex2bn(&myself->connection->rsa_key->n, pubkey) != strlen(pubkey)) {
+               free(key);
+               if(!get_config_string(lookup_config(config_tree, "PublicKey"), &pubkey)) {
+                       BN_free(d);
+                       logger(LOG_ERR, "PrivateKey used but no PublicKey found!");
+                       return false;
+               }
+               if(BN_hex2bn(&n, pubkey) != strlen(pubkey)) {
+                       free(pubkey);
+                       BN_free(d);
                        logger(LOG_ERR, "Invalid PublicKey for myself!");
                        return false;
                }
-               BN_hex2bn(&myself->connection->rsa_key->e, "FFFF");
-               free(key);
                free(pubkey);
+               BN_hex2bn(&e, "FFFF");
+               if(!n || !e || !d || RSA_set0_key(myself->connection->rsa_key, n, e, d) != 1) {
+                       BN_free(d);
+                       BN_free(e);
+                       BN_free(n);
+                       logger(LOG_ERR, "RSA_set0_key() failed with PrivateKey for myself!");
+                       return false;
+               }
                return true;
        }
 
@@ -200,15 +227,12 @@ static bool read_rsa_private_key(void) {
 #if !defined(HAVE_MINGW) && !defined(HAVE_CYGWIN)
        struct stat s;
 
-       if(fstat(fileno(fp), &s)) {
-               logger(LOG_ERR, "Could not stat RSA private key file `%s': %s'",
-                               fname, strerror(errno));
-               free(fname);
-               return false;
+       if(!fstat(fileno(fp), &s)) {
+               if(s.st_mode & ~0100700)
+                       logger(LOG_WARNING, "Warning: insecure file permissions for RSA private key file `%s'!", fname);
+       } else {
+               logger(LOG_WARNING, "Could not stat RSA private key file `%s': %s'", fname, strerror(errno));
        }
-
-       if(s.st_mode & ~0100700)
-               logger(LOG_WARNING, "Warning: insecure file permissions for RSA private key file `%s'!", fname);
 #endif
 
        myself->connection->rsa_key = PEM_read_RSAPrivateKey(fp, NULL, NULL, NULL);
@@ -299,10 +323,12 @@ char *get_name(void) {
                if(!envname) {
                        if(strcmp(name + 1, "HOST")) {
                                fprintf(stderr, "Invalid Name: environment variable %s does not exist\n", name + 1);
+                               free(name);
                                return false;
                        }
                        if(gethostname(hostname, sizeof hostname) || !*hostname) {
                                fprintf(stderr, "Could not get hostname: %s\n", strerror(errno));
+                               free(name);
                                return false;
                        }
                        hostname[31] = 0;
@@ -340,6 +366,7 @@ static bool setup_myself(void) {
        bool choice;
        int i, err;
        int replaywin_int;
+       bool port_specified = false;
 
        myself = new_node();
        myself->connection = new_connection();
@@ -355,6 +382,8 @@ static bool setup_myself(void) {
                return false;
        }
 
+       /* Read tinc.conf and our own host config file */
+
        myself->name = name;
        myself->connection->name = xstrdup(name);
        xasprintf(&fname, "%s/hosts/%s", confbase, name);
@@ -367,6 +396,10 @@ static bool setup_myself(void) {
 
        if(!get_config_string(lookup_config(config_tree, "Port"), &myport))
                myport = xstrdup("655");
+       else
+               port_specified = true;
+
+       /* Ensure myport is numeric */
 
        if(!atoi(myport)) {
                struct addrinfo *ai = str2addrinfo("localhost", myport, SOCK_DGRAM);
@@ -378,8 +411,7 @@ static bool setup_myself(void) {
                sockaddr2str(&sa, NULL, &myport);
        }
 
-       get_config_string(lookup_config(config_tree, "Proxy"), &proxy);
-       if(proxy) {
+       if(get_config_string(lookup_config(config_tree, "Proxy"), &proxy)) {
                if((space = strchr(proxy, ' ')))
                        *space++ = 0;
 
@@ -397,6 +429,7 @@ static bool setup_myself(void) {
                        proxytype = PROXY_EXEC;
                } else {
                        logger(LOG_ERR, "Unknown proxy type %s!", proxy);
+                       free(proxy);
                        return false;
                }
 
@@ -408,6 +441,7 @@ static bool setup_myself(void) {
                        case PROXY_EXEC:
                                if(!space || !*space) {
                                        logger(LOG_ERR, "Argument expected for proxy type exec!");
+                                       free(proxy);
                                        return false;
                                }
                                proxyhost =  xstrdup(space);
@@ -426,6 +460,7 @@ static bool setup_myself(void) {
                                        *space++ = 0, proxypass = space;
                                if(!proxyhost || !*proxyhost || !proxyport || !*proxyport) {
                                        logger(LOG_ERR, "Host and port argument expected for proxy!");
+                                       free(proxy);
                                        return false;
                                }
                                proxyhost = xstrdup(proxyhost);
@@ -479,6 +514,7 @@ static bool setup_myself(void) {
                        routing_mode = RMODE_HUB;
                else {
                        logger(LOG_ERR, "Invalid routing mode!");
+                       free(mode);
                        return false;
                }
                free(mode);
@@ -493,6 +529,7 @@ static bool setup_myself(void) {
                        forwarding_mode = FMODE_KERNEL;
                else {
                        logger(LOG_ERR, "Invalid forwarding mode!");
+                       free(mode);
                        return false;
                }
                free(mode);
@@ -519,6 +556,7 @@ static bool setup_myself(void) {
                        broadcast_mode = BMODE_DIRECT;
                else {
                        logger(LOG_ERR, "Invalid broadcast mode!");
+                       free(mode);
                        return false;
                }
                free(mode);
@@ -526,7 +564,12 @@ static bool setup_myself(void) {
 
 #if !defined(SOL_IP) || !defined(IP_TOS)
        if(priorityinheritance)
-               logger(LOG_WARNING, "%s not supported on this platform", "PriorityInheritance");
+               logger(LOG_WARNING, "%s not supported on this platform for IPv4 connection", "PriorityInheritance");
+#endif
+
+#if !defined(IPPROTO_IPV6) || !defined(IPV6_TCLASS)
+       if(priorityinheritance)
+               logger(LOG_WARNING, "%s not supported on this platform for IPv6 connection", "PriorityInheritance");
 #endif
 
        if(!get_config_int(lookup_config(config_tree, "MACExpire"), &macexpire))
@@ -540,6 +583,18 @@ static bool setup_myself(void) {
        } else
                maxtimeout = 900;
 
+       if(get_config_int(lookup_config(config_tree, "MinTimeout"), &mintimeout)) {
+                       if(mintimeout < 0) {
+                               logger(LOG_ERR, "Bogus minimum timeout!");
+                               return false;
+                       }
+                       if(mintimeout > maxtimeout) {
+                               logger(LOG_WARNING, "Minimum timeout (%d s) cannot be larger than maximum timeout (%d s). Correcting !", mintimeout, maxtimeout );
+                               mintimeout=maxtimeout;
+                       }
+               } else
+                       mintimeout = 0;
+
        if(get_config_int(lookup_config(config_tree, "UDPRcvBuf"), &udp_rcvbuf)) {
                if(udp_rcvbuf <= 0) {
                        logger(LOG_ERR, "UDPRcvBuf cannot be negative!");
@@ -571,6 +626,7 @@ static bool setup_myself(void) {
                        addressfamily = AF_UNSPEC;
                else {
                        logger(LOG_ERR, "Invalid address family!");
+                       free(afname);
                        return false;
                }
                free(afname);
@@ -580,8 +636,7 @@ static bool setup_myself(void) {
 
        /* Generate packet encryption key */
 
-       if(get_config_string
-          (lookup_config(config_tree, "Cipher"), &cipher)) {
+       if(get_config_string(lookup_config(config_tree, "Cipher"), &cipher)) {
                if(!strcasecmp(cipher, "none")) {
                        myself->incipher = NULL;
                } else {
@@ -589,18 +644,31 @@ static bool setup_myself(void) {
 
                        if(!myself->incipher) {
                                logger(LOG_ERR, "Unrecognized cipher type!");
+                               free(cipher);
                                return false;
                        }
                }
+               free(cipher);
        } else
-               myself->incipher = EVP_bf_cbc();
+               myself->incipher = EVP_aes_256_cbc();
 
        if(myself->incipher)
-               myself->inkeylength = myself->incipher->key_len + myself->incipher->iv_len;
+               myself->inkeylength = EVP_CIPHER_key_length(myself->incipher) + EVP_CIPHER_iv_length(myself->incipher);
        else
                myself->inkeylength = 1;
 
-       myself->connection->outcipher = EVP_bf_ofb();
+       /* We need to use OFB mode for the meta protocol. Use AES for this,
+          but try to match the key size with the one from the cipher selected
+          by Cipher.
+       */
+
+       int keylen = EVP_CIPHER_key_length(myself->incipher);
+       if(keylen <= 16)
+               myself->connection->outcipher = EVP_aes_128_ctr();
+       else if(keylen <= 24)
+               myself->connection->outcipher = EVP_aes_192_ctr();
+       else
+               myself->connection->outcipher = EVP_aes_256_ctr();
 
        if(!get_config_int(lookup_config(config_tree, "KeyExpire"), &keylifetime))
                keylifetime = 3600;
@@ -617,17 +685,20 @@ static bool setup_myself(void) {
 
                        if(!myself->indigest) {
                                logger(LOG_ERR, "Unrecognized digest type!");
+                               free(digest);
                                return false;
                        }
                }
+
+               free(digest);
        } else
-               myself->indigest = EVP_sha1();
+               myself->indigest = EVP_sha256();
 
-       myself->connection->outdigest = EVP_sha1();
+       myself->connection->outdigest = EVP_sha256();
 
        if(get_config_int(lookup_config(config_tree, "MACLength"), &myself->inmaclength)) {
                if(myself->indigest) {
-                       if(myself->inmaclength > myself->indigest->md_size) {
+                       if(myself->inmaclength > EVP_MD_size(myself->indigest)) {
                                logger(LOG_ERR, "MAC length exceeds size of digest!");
                                return false;
                        } else if(myself->inmaclength < 0) {
@@ -683,6 +754,7 @@ static bool setup_myself(void) {
                else if(!strcasecmp(type, "vde"))
                        devops = vde_devops;
 #endif
+               free(type);
        }
 
        if(!devops.setup())
@@ -694,6 +766,12 @@ static bool setup_myself(void) {
        xasprintf(&envp[2], "INTERFACE=%s", iface ? : "");
        xasprintf(&envp[3], "NAME=%s", myself->name);
 
+#ifdef HAVE_MINGW
+       Sleep(1000);
+#endif
+#ifdef HAVE_CYGWIN
+       sleep(1);
+#endif
        execute_script("tinc-up", envp);
 
        for(i = 0; i < 4; i++)
@@ -771,6 +849,10 @@ static bool setup_myself(void) {
                        hint.ai_protocol = IPPROTO_TCP;
                        hint.ai_flags = AI_PASSIVE;
 
+#if HAVE_DECL_RES_INIT
+                       // ensure glibc reloads /etc/resolv.conf.
+                       res_init();
+#endif
                        err = getaddrinfo(address && *address ? address : NULL, port, &hint, &ai);
                        free(address);
 
@@ -812,13 +894,27 @@ static bool setup_myself(void) {
                } while(cfg);
        }
 
-       if(listen_sockets)
-               logger(LOG_NOTICE, "Ready");
-       else {
+       if(!listen_sockets) {
                logger(LOG_ERR, "Unable to create any listening socket!");
                return false;
        }
 
+       /* If no Port option was specified, set myport to the port used by the first listening socket. */
+
+       if(!port_specified) {
+               sockaddr_t sa;
+               socklen_t salen = sizeof sa;
+               if(!getsockname(listen_socket[0].udp, &sa.sa, &salen)) {
+                       free(myport);
+                       sockaddr2str(&sa, NULL, &myport);
+                       if(!myport)
+                               myport = xstrdup("655");
+               }
+       }
+
+       /* Done. */
+
+       logger(LOG_NOTICE, "Ready");
        return true;
 }