X-Git-Url: https://tinc-vpn.org/git/browse?a=blobdiff_plain;f=src%2Fprotocol_auth.c;h=0a7ad1ca383ea8c0bf21cd44df7c8e762a7f59dc;hb=390d25f0b80dd7418e147de3561c70461628574d;hp=8fe8b38bf84d4b55a9f819ef81d950d00146cade;hpb=5fc1ed17f41f0c535cf57a4b7e00cd6d45759503;p=tinc diff --git a/src/protocol_auth.c b/src/protocol_auth.c index 8fe8b38b..0a7ad1ca 100644 --- a/src/protocol_auth.c +++ b/src/protocol_auth.c @@ -1,7 +1,7 @@ /* protocol_auth.c -- handle the meta-protocol, authentication - Copyright (C) 1999-2002 Ivo Timmermans , - 2000-2002 Guus Sliepen + Copyright (C) 1999-2005 Ivo Timmermans, + 2000-2014 Guus Sliepen This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by @@ -13,573 +13,889 @@ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. - You should have received a copy of the GNU General Public License - along with this program; if not, write to the Free Software - Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. - - $Id: protocol_auth.c,v 1.1.4.15 2002/09/09 19:39:59 guus Exp $ + You should have received a copy of the GNU General Public License along + with this program; if not, write to the Free Software Foundation, Inc., + 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */ -#include "config.h" - -#include -#include -#include -#include -#include -#include - -#include -#include -#include - -#include -#include -#include - -#ifndef HAVE_RAND_PSEUDO_BYTES -#define RAND_pseudo_bytes RAND_bytes -#endif +#include "system.h" #include "conf.h" -#include "net.h" -#include "netutl.h" -#include "protocol.h" -#include "meta.h" #include "connection.h" -#include "node.h" +#include "control.h" +#include "control_common.h" +#include "cipher.h" +#include "crypto.h" +#include "device.h" +#include "digest.h" +#include "ecdsa.h" #include "edge.h" #include "graph.h" +#include "logger.h" +#include "meta.h" +#include "names.h" +#include "net.h" +#include "netutl.h" +#include "node.h" +#include "prf.h" +#include "protocol.h" +#include "rsa.h" +#include "script.h" +#include "sptps.h" +#include "utils.h" +#include "xalloc.h" + +#include "ed25519/sha512.h" + +ecdsa_t *invitation_key = NULL; + +static bool send_proxyrequest(connection_t *c) { + switch(proxytype) { + case PROXY_HTTP: { + char *host; + char *port; + + sockaddr2str(&c->address, &host, &port); + send_request(c, "CONNECT %s:%s HTTP/1.1\r\n\r", host, port); + free(host); + free(port); + return true; + } + case PROXY_SOCKS4: { + if(c->address.sa.sa_family != AF_INET) { + logger(DEBUG_ALWAYS, LOG_ERR, "Cannot connect to an IPv6 host through a SOCKS 4 proxy!"); + return false; + } + char s4req[9 + (proxyuser ? strlen(proxyuser) : 0)]; + s4req[0] = 4; + s4req[1] = 1; + memcpy(s4req + 2, &c->address.in.sin_port, 2); + memcpy(s4req + 4, &c->address.in.sin_addr, 4); + if(proxyuser) + memcpy(s4req + 8, proxyuser, strlen(proxyuser)); + s4req[sizeof s4req - 1] = 0; + c->tcplen = 8; + return send_meta(c, s4req, sizeof s4req); + } + case PROXY_SOCKS5: { + int len = 3 + 6 + (c->address.sa.sa_family == AF_INET ? 4 : 16); + c->tcplen = 2; + if(proxypass) + len += 3 + strlen(proxyuser) + strlen(proxypass); + char s5req[len]; + int i = 0; + s5req[i++] = 5; + s5req[i++] = 1; + if(proxypass) { + s5req[i++] = 2; + s5req[i++] = 1; + s5req[i++] = strlen(proxyuser); + memcpy(s5req + i, proxyuser, strlen(proxyuser)); + i += strlen(proxyuser); + s5req[i++] = strlen(proxypass); + memcpy(s5req + i, proxypass, strlen(proxypass)); + i += strlen(proxypass); + c->tcplen += 2; + } else { + s5req[i++] = 0; + } + s5req[i++] = 5; + s5req[i++] = 1; + s5req[i++] = 0; + if(c->address.sa.sa_family == AF_INET) { + s5req[i++] = 1; + memcpy(s5req + i, &c->address.in.sin_addr, 4); + i += 4; + memcpy(s5req + i, &c->address.in.sin_port, 2); + i += 2; + c->tcplen += 10; + } else if(c->address.sa.sa_family == AF_INET6) { + s5req[i++] = 3; + memcpy(s5req + i, &c->address.in6.sin6_addr, 16); + i += 16; + memcpy(s5req + i, &c->address.in6.sin6_port, 2); + i += 2; + c->tcplen += 22; + } else { + logger(DEBUG_ALWAYS, LOG_ERR, "Address family %x not supported for SOCKS 5 proxies!", c->address.sa.sa_family); + return false; + } + if(i > len) + abort(); + return send_meta(c, s5req, sizeof s5req); + } + case PROXY_SOCKS4A: + logger(DEBUG_ALWAYS, LOG_ERR, "Proxy type not implemented yet"); + return false; + case PROXY_EXEC: + return true; + default: + logger(DEBUG_ALWAYS, LOG_ERR, "Unknown proxy type"); + return false; + } +} -#include "system.h" +bool send_id(connection_t *c) { + gettimeofday(&c->start, NULL); -int send_id(connection_t *c) -{ - cp(); - return send_request(c, "%d %s %d", ID, myself->connection->name, myself->connection->protocol_version); + int minor = 0; + + if(experimental) { + if(c->outgoing && !read_ecdsa_public_key(c)) + minor = 1; + else + minor = myself->connection->protocol_minor; + } + + if(proxytype && c->outgoing) + if(!send_proxyrequest(c)) + return false; + + return send_request(c, "%d %s %d.%d", ID, myself->connection->name, myself->connection->protocol_major, minor); } -int id_h(connection_t *c) -{ - char name[MAX_STRING_SIZE]; - int bla; - cp(); - if(sscanf(c->buffer, "%*d "MAX_STRING" %d", name, &c->protocol_version) != 2) - { - syslog(LOG_ERR, _("Got bad %s from %s (%s)"), "ID", c->name, c->hostname); - return -1; - } - - /* Check if identity is a valid name */ - - if(check_id(name)) - { - syslog(LOG_ERR, _("Got bad %s from %s (%s): %s"), "ID", c->name, c->hostname, "invalid name"); - return -1; - } - - /* If we set c->name in advance, make sure we are connected to the right host */ - - if(c->name) - { - if(strcmp(c->name, name)) - { - syslog(LOG_ERR, _("Peer %s is %s instead of %s"), c->hostname, name, c->name); - return -1; - } - } - else - c->name = xstrdup(name); - - /* Check if version matches */ - - if(c->protocol_version != myself->connection->protocol_version) - { - syslog(LOG_ERR, _("Peer %s (%s) uses incompatible version %d"), - c->name, c->hostname, c->protocol_version); - return -1; - } - - if(bypass_security) - { - if(!c->config_tree) - init_configuration(&c->config_tree); - c->allow_request = ACK; - return send_ack(c); - } - - if(!c->config_tree) - { - init_configuration(&c->config_tree); - - bla = read_connection_config(c); - - if(bla) - { - syslog(LOG_ERR, _("Peer %s had unknown identity (%s)"), c->hostname, c->name); - return -1; - } - } - - if(read_rsa_public_key(c)) - { - return -1; - } - - /* Check some options */ - - if((get_config_bool(lookup_config(c->config_tree, "IndirectData"), &bla) && bla) || myself->options & OPTION_INDIRECT) - c->options |= OPTION_INDIRECT; - - if((get_config_bool(lookup_config(c->config_tree, "TCPOnly"), &bla) && bla) || myself->options & OPTION_TCPONLY) - c->options |= OPTION_TCPONLY | OPTION_INDIRECT; - - c->allow_request = METAKEY; - cp(); - return send_metakey(c); +static bool finalize_invitation(connection_t *c, const char *data, uint16_t len) { + if(strchr(data, '\n')) { + logger(DEBUG_ALWAYS, LOG_ERR, "Received invalid key from invited node %s (%s)!\n", c->name, c->hostname); + return false; + } + + // Create a new host config file + char filename[PATH_MAX]; + snprintf(filename, sizeof filename, "%s" SLASH "hosts" SLASH "%s", confbase, c->name); + if(!access(filename, F_OK)) { + logger(DEBUG_ALWAYS, LOG_ERR, "Host config file for %s (%s) already exists!\n", c->name, c->hostname); + return false; + } + + FILE *f = fopen(filename, "w"); + if(!f) { + logger(DEBUG_ALWAYS, LOG_ERR, "Error trying to create %s: %s\n", filename, strerror(errno)); + return false; + } + + fprintf(f, "Ed25519PublicKey = %s\n", data); + fclose(f); + + logger(DEBUG_CONNECTIONS, LOG_INFO, "Key succesfully received from %s (%s)", c->name, c->hostname); + + // Call invitation-accepted script + char *envp[7] = {NULL}; + char *address, *port; + + xasprintf(&envp[0], "NETNAME=%s", netname ? : ""); + xasprintf(&envp[1], "DEVICE=%s", device ? : ""); + xasprintf(&envp[2], "INTERFACE=%s", iface ? : ""); + xasprintf(&envp[3], "NODE=%s", c->name); + sockaddr2str(&c->address, &address, &port); + xasprintf(&envp[4], "REMOTEADDRESS=%s", address); + xasprintf(&envp[5], "NAME=%s", myself->name); + + execute_script("invitation-accepted", envp); + + for(int i = 0; envp[i] && i < 7; i++) + free(envp[i]); + + sptps_send_record(&c->sptps, 2, data, 0); + return true; } -int send_metakey(connection_t *c) -{ - char buffer[MAX_STRING_SIZE]; - int len, x; - cp(); - len = RSA_size(c->rsa_key); - - /* Allocate buffers for the meta key */ - - if(!c->outkey) - c->outkey = xmalloc(len); - - if(!c->outctx) - c->outctx = xmalloc(sizeof(*c->outctx)); - cp(); - /* Copy random data to the buffer */ - - RAND_bytes(c->outkey, len); - - /* The message we send must be smaller than the modulus of the RSA key. - By definition, for a key of k bits, the following formula holds: - - 2^(k-1) <= modulus < 2^(k) - - Where ^ means "to the power of", not "xor". - This means that to be sure, we must choose our message < 2^(k-1). - This can be done by setting the most significant bit to zero. - */ - - c->outkey[0] &= 0x7F; - - if(debug_lvl >= DEBUG_SCARY_THINGS) - { - bin2hex(c->outkey, buffer, len); - buffer[len*2] = '\0'; - syslog(LOG_DEBUG, _("Generated random meta key (unencrypted): %s"), buffer); - } - - /* Encrypt the random data - - We do not use one of the PKCS padding schemes here. - This is allowed, because we encrypt a totally random string - with a length equal to that of the modulus of the RSA key. - */ - - if(RSA_public_encrypt(len, c->outkey, buffer, c->rsa_key, RSA_NO_PADDING) != len) - { - syslog(LOG_ERR, _("Error during encryption of meta key for %s (%s)"), c->name, c->hostname); - return -1; - } - cp(); - /* Convert the encrypted random data to a hexadecimal formatted string */ - - bin2hex(buffer, buffer, len); - buffer[len*2] = '\0'; - - /* Send the meta key */ - - x = send_request(c, "%d %d %d %d %d %s", METAKEY, - c->outcipher?c->outcipher->nid:0, c->outdigest?c->outdigest->type:0, - c->outmaclength, c->outcompression, buffer); - - /* Further outgoing requests are encrypted with the key we just generated */ - - if(c->outcipher) - { - EVP_EncryptInit(c->outctx, c->outcipher, - c->outkey + len - c->outcipher->key_len, - c->outkey + len - c->outcipher->key_len - c->outcipher->iv_len); - - c->status.encryptout = 1; - } - cp(); - return x; +static bool receive_invitation_sptps(void *handle, uint8_t type, const void *data, uint16_t len) { + connection_t *c = handle; + + if(type == 128) + return true; + + if(type == 1 && c->status.invitation_used) + return finalize_invitation(c, data, len); + + if(type != 0 || len != 18 || c->status.invitation_used) + return false; + + // Recover the filename from the cookie and the key + char *fingerprint = ecdsa_get_base64_public_key(invitation_key); + char hashbuf[18 + strlen(fingerprint)]; + char cookie[64]; + memcpy(hashbuf, data, 18); + memcpy(hashbuf + 18, fingerprint, sizeof hashbuf - 18); + sha512(hashbuf, sizeof hashbuf, cookie); + b64encode_urlsafe(cookie, cookie, 18); + free(fingerprint); + + char filename[PATH_MAX], usedname[PATH_MAX]; + snprintf(filename, sizeof filename, "%s" SLASH "invitations" SLASH "%s", confbase, cookie); + snprintf(usedname, sizeof usedname, "%s" SLASH "invitations" SLASH "%s.used", confbase, cookie); + + // Atomically rename the invitation file + if(rename(filename, usedname)) { + if(errno == ENOENT) + logger(DEBUG_ALWAYS, LOG_ERR, "Peer %s tried to use non-existing invitation %s\n", c->hostname, cookie); + else + logger(DEBUG_ALWAYS, LOG_ERR, "Error trying to rename invitation %s\n", cookie); + return false; + } + + // Open the renamed file + FILE *f = fopen(usedname, "r"); + if(!f) { + logger(DEBUG_ALWAYS, LOG_ERR, "Error trying to open invitation %s\n", cookie); + return false; + } + + // Read the new node's Name from the file + char buf[1024]; + fgets(buf, sizeof buf, f); + if(*buf) + buf[strlen(buf) - 1] = 0; + + len = strcspn(buf, " \t="); + char *name = buf + len; + name += strspn(name, " \t"); + if(*name == '=') { + name++; + name += strspn(name, " \t"); + } + buf[len] = 0; + + if(!*buf || !*name || strcasecmp(buf, "Name") || !check_id(name)) { + logger(DEBUG_ALWAYS, LOG_ERR, "Invalid invitation file %s\n", cookie); + fclose(f); + return false; + } + + free(c->name); + c->name = xstrdup(name); + + // Send the node the contents of the invitation file + rewind(f); + size_t result; + while((result = fread(buf, 1, sizeof buf, f))) + sptps_send_record(&c->sptps, 0, buf, result); + sptps_send_record(&c->sptps, 1, buf, 0); + fclose(f); + unlink(usedname); + + c->status.invitation_used = true; + + logger(DEBUG_CONNECTIONS, LOG_INFO, "Invitation %s succesfully sent to %s (%s)", cookie, c->name, c->hostname); + return true; +} + +bool id_h(connection_t *c, const char *request) { + char name[MAX_STRING_SIZE]; + + if(sscanf(request, "%*d " MAX_STRING " %d.%d", name, &c->protocol_major, &c->protocol_minor) < 2) { + logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s)", "ID", c->name, + c->hostname); + return false; + } + + /* Check if this is a control connection */ + + if(name[0] == '^' && !strcmp(name + 1, controlcookie)) { + c->status.control = true; + c->allow_request = CONTROL; + c->last_ping_time = now.tv_sec + 3600; + + free(c->name); + c->name = xstrdup(""); + + return send_request(c, "%d %d %d", ACK, TINC_CTL_VERSION_CURRENT, getpid()); + } + + if(name[0] == '?') { + if(!invitation_key) { + logger(DEBUG_ALWAYS, LOG_ERR, "Got invitation from %s but we don't have an invitation key", c->hostname); + return false; + } + + c->ecdsa = ecdsa_set_base64_public_key(name + 1); + if(!c->ecdsa) { + logger(DEBUG_ALWAYS, LOG_ERR, "Got bad invitation from %s", c->hostname); + return false; + } + + c->status.invitation = true; + char *mykey = ecdsa_get_base64_public_key(invitation_key); + if(!mykey) + return false; + if(!send_request(c, "%d %s", ACK, mykey)) + return false; + free(mykey); + + c->protocol_minor = 2; + + return sptps_start(&c->sptps, c, false, false, invitation_key, c->ecdsa, "tinc invitation", 15, send_meta_sptps, receive_invitation_sptps); + } + + /* Check if identity is a valid name */ + + if(!check_id(name)) { + logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s): %s", "ID", c->name, + c->hostname, "invalid name"); + return false; + } + + /* If this is an outgoing connection, make sure we are connected to the right host */ + + if(c->outgoing) { + if(strcmp(c->name, name)) { + logger(DEBUG_ALWAYS, LOG_ERR, "Peer %s is %s instead of %s", c->hostname, name, + c->name); + return false; + } + } else { + if(c->name) + free(c->name); + c->name = xstrdup(name); + } + + /* Check if version matches */ + + if(c->protocol_major != myself->connection->protocol_major) { + logger(DEBUG_ALWAYS, LOG_ERR, "Peer %s (%s) uses incompatible version %d.%d", + c->name, c->hostname, c->protocol_major, c->protocol_minor); + return false; + } + + if(bypass_security) { + if(!c->config_tree) + init_configuration(&c->config_tree); + c->allow_request = ACK; + return send_ack(c); + } + + if(!experimental) + c->protocol_minor = 0; + + if(!c->config_tree) { + init_configuration(&c->config_tree); + + if(!read_host_config(c->config_tree, c->name)) { + logger(DEBUG_ALWAYS, LOG_ERR, "Peer %s had unknown identity (%s)", c->hostname, c->name); + return false; + } + + if(experimental) + read_ecdsa_public_key(c); + /* Ignore failures if no key known yet */ + } + + if(c->protocol_minor && !ecdsa_active(c->ecdsa)) + c->protocol_minor = 1; + + /* Forbid version rollback for nodes whose Ed25519 key we know */ + + if(ecdsa_active(c->ecdsa) && c->protocol_minor < 1) { + logger(DEBUG_ALWAYS, LOG_ERR, "Peer %s (%s) tries to roll back protocol version to %d.%d", + c->name, c->hostname, c->protocol_major, c->protocol_minor); + return false; + } + + c->allow_request = METAKEY; + + if(c->protocol_minor >= 2) { + c->allow_request = ACK; + char label[25 + strlen(myself->name) + strlen(c->name)]; + + if(c->outgoing) + snprintf(label, sizeof label, "tinc TCP key expansion %s %s", myself->name, c->name); + else + snprintf(label, sizeof label, "tinc TCP key expansion %s %s", c->name, myself->name); + + return sptps_start(&c->sptps, c, c->outgoing, false, myself->connection->ecdsa, c->ecdsa, label, sizeof label, send_meta_sptps, receive_meta_sptps); + } else { + return send_metakey(c); + } } -int metakey_h(connection_t *c) -{ - char buffer[MAX_STRING_SIZE]; - int cipher, digest, maclength, compression; - int len; - cp(); - if(sscanf(c->buffer, "%*d %d %d %d %d "MAX_STRING, &cipher, &digest, &maclength, &compression, buffer) != 5) - { - syslog(LOG_ERR, _("Got bad %s from %s (%s)"), "METAKEY", c->name, c->hostname); - return -1; - } - cp(); - len = RSA_size(myself->connection->rsa_key); - - /* Check if the length of the meta key is all right */ - - if(strlen(buffer) != len*2) - { - syslog(LOG_ERR, _("Possible intruder %s (%s): %s"), c->name, c->hostname, "wrong keylength"); - return -1; - } - - /* Allocate buffers for the meta key */ - cp(); - if(!c->inkey) - c->inkey = xmalloc(len); - - if(!c->inctx) - c->inctx = xmalloc(sizeof(*c->inctx)); - - /* Convert the challenge from hexadecimal back to binary */ - cp(); - hex2bin(buffer,buffer,len); - - /* Decrypt the meta key */ - cp(); - if(RSA_private_decrypt(len, buffer, c->inkey, myself->connection->rsa_key, RSA_NO_PADDING) != len) /* See challenge() */ - { - syslog(LOG_ERR, _("Error during encryption of meta key for %s (%s)"), c->name, c->hostname); - return -1; - } - - if(debug_lvl >= DEBUG_SCARY_THINGS) - { - bin2hex(c->inkey, buffer, len); - buffer[len*2] = '\0'; - syslog(LOG_DEBUG, _("Received random meta key (unencrypted): %s"), buffer); - } - - /* All incoming requests will now be encrypted. */ - cp(); - /* Check and lookup cipher and digest algorithms */ - - if(cipher) - { - c->incipher = EVP_get_cipherbynid(cipher); - if(!c->incipher) - { - syslog(LOG_ERR, _("%s (%s) uses unknown cipher!"), c->name, c->hostname); - return -1; - } - - EVP_DecryptInit(c->inctx, c->incipher, - c->inkey + len - c->incipher->key_len, - c->inkey + len - c->incipher->key_len - c->incipher->iv_len); - - c->status.decryptin = 1; - } - else - { - c->incipher = NULL; - } - - c->inmaclength = maclength; - - if(digest) - { - c->indigest = EVP_get_digestbynid(digest); - if(!c->indigest) - { - syslog(LOG_ERR, _("Node %s (%s) uses unknown digest!"), c->name, c->hostname); - return -1; - } - - if(c->inmaclength > c->indigest->md_size || c->inmaclength < 0) - { - syslog(LOG_ERR, _("%s (%s) uses bogus MAC length!"), c->name, c->hostname); - return -1; - } - } - else - { - c->indigest = NULL; - } - - c->incompression = compression; - - c->allow_request = CHALLENGE; - cp(); - return send_challenge(c); +bool send_metakey(connection_t *c) { +#ifdef DISABLE_LEGACY + return false; +#else + if(!myself->connection->rsa) { + logger(DEBUG_CONNECTIONS, LOG_ERR, "Peer %s (%s) uses legacy protocol which we don't support", c->name, c->hostname); + return false; + } + + if(!read_rsa_public_key(c)) + return false; + + if(!(c->outcipher = cipher_open_blowfish_ofb())) + return false; + + if(!(c->outdigest = digest_open_sha1(-1))) + return false; + + const size_t len = rsa_size(c->rsa); + char key[len]; + char enckey[len]; + char hexkey[2 * len + 1]; + + /* Create a random key */ + + randomize(key, len); + + /* The message we send must be smaller than the modulus of the RSA key. + By definition, for a key of k bits, the following formula holds: + + 2^(k-1) <= modulus < 2^(k) + + Where ^ means "to the power of", not "xor". + This means that to be sure, we must choose our message < 2^(k-1). + This can be done by setting the most significant bit to zero. + */ + + key[0] &= 0x7F; + + if(!cipher_set_key_from_rsa(c->outcipher, key, len, true)) + return false; + + if(debug_level >= DEBUG_SCARY_THINGS) { + bin2hex(key, hexkey, len); + logger(DEBUG_SCARY_THINGS, LOG_DEBUG, "Generated random meta key (unencrypted): %s", hexkey); + } + + /* Encrypt the random data + + We do not use one of the PKCS padding schemes here. + This is allowed, because we encrypt a totally random string + with a length equal to that of the modulus of the RSA key. + */ + + if(!rsa_public_encrypt(c->rsa, key, len, enckey)) { + logger(DEBUG_ALWAYS, LOG_ERR, "Error during encryption of meta key for %s (%s)", c->name, c->hostname); + return false; + } + + /* Convert the encrypted random data to a hexadecimal formatted string */ + + bin2hex(enckey, hexkey, len); + + /* Send the meta key */ + + bool result = send_request(c, "%d %d %d %d %d %s", METAKEY, + cipher_get_nid(c->outcipher), + digest_get_nid(c->outdigest), c->outmaclength, + c->outcompression, hexkey); + + c->status.encryptout = true; + return result; +#endif } -int send_challenge(connection_t *c) -{ - char buffer[MAX_STRING_SIZE]; - int len, x; - cp(); - /* CHECKME: what is most reasonable value for len? */ +bool metakey_h(connection_t *c, const char *request) { +#ifdef DISABLE_LEGACY + return false; +#else + if(!myself->connection->rsa) + return false; + + char hexkey[MAX_STRING_SIZE]; + int cipher, digest, maclength, compression; + const size_t len = rsa_size(myself->connection->rsa); + char enckey[len]; + char key[len]; + + if(sscanf(request, "%*d %d %d %d %d " MAX_STRING, &cipher, &digest, &maclength, &compression, hexkey) != 5) { + logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s)", "METAKEY", c->name, c->hostname); + return false; + } + + /* Convert the challenge from hexadecimal back to binary */ + + int inlen = hex2bin(hexkey, enckey, sizeof enckey); - len = RSA_size(c->rsa_key); + /* Check if the length of the meta key is all right */ - /* Allocate buffers for the challenge */ + if(inlen != len) { + logger(DEBUG_ALWAYS, LOG_ERR, "Possible intruder %s (%s): %s", c->name, c->hostname, "wrong keylength"); + return false; + } + + /* Decrypt the meta key */ + + if(!rsa_private_decrypt(myself->connection->rsa, enckey, len, key)) { + logger(DEBUG_ALWAYS, LOG_ERR, "Error during decryption of meta key for %s (%s)", c->name, c->hostname); + return false; + } + + if(debug_level >= DEBUG_SCARY_THINGS) { + bin2hex(key, hexkey, len); + logger(DEBUG_SCARY_THINGS, LOG_DEBUG, "Received random meta key (unencrypted): %s", hexkey); + } - if(!c->hischallenge) - c->hischallenge = xmalloc(len); - cp(); - /* Copy random data to the buffer */ + /* Check and lookup cipher and digest algorithms */ - RAND_bytes(c->hischallenge, len); + if(cipher) { + if(!(c->incipher = cipher_open_by_nid(cipher)) || !cipher_set_key_from_rsa(c->incipher, key, len, false)) { + logger(DEBUG_ALWAYS, LOG_ERR, "Error during initialisation of cipher from %s (%s)", c->name, c->hostname); + return false; + } + } else { + c->incipher = NULL; + } - cp(); - /* Convert to hex */ + if(digest) { + if(!(c->indigest = digest_open_by_nid(digest, -1))) { + logger(DEBUG_ALWAYS, LOG_ERR, "Error during initialisation of digest from %s (%s)", c->name, c->hostname); + return false; + } + } else { + c->indigest = NULL; + } - bin2hex(c->hischallenge, buffer, len); - buffer[len*2] = '\0'; + c->status.decryptin = true; - cp(); - /* Send the challenge */ + c->allow_request = CHALLENGE; - x = send_request(c, "%d %s", CHALLENGE, buffer); - cp(); - return x; + return send_challenge(c); +#endif } -int challenge_h(connection_t *c) -{ - char buffer[MAX_STRING_SIZE]; - int len; - cp(); - if(sscanf(c->buffer, "%*d "MAX_STRING, buffer) != 1) - { - syslog(LOG_ERR, _("Got bad %s from %s (%s)"), "CHALLENGE", c->name, c->hostname); - return -1; - } +bool send_challenge(connection_t *c) { +#ifdef DISABLE_LEGACY + return false; +#else + const size_t len = rsa_size(c->rsa); + char buffer[len * 2 + 1]; + + if(!c->hischallenge) + c->hischallenge = xrealloc(c->hischallenge, len); - len = RSA_size(myself->connection->rsa_key); + /* Copy random data to the buffer */ - /* Check if the length of the challenge is all right */ + randomize(c->hischallenge, len); - if(strlen(buffer) != len*2) - { - syslog(LOG_ERR, _("Possible intruder %s (%s): %s"), c->name, c->hostname, "wrong challenge length"); - return -1; - } + /* Convert to hex */ - /* Allocate buffers for the challenge */ + bin2hex(c->hischallenge, buffer, len); - if(!c->mychallenge) - c->mychallenge = xmalloc(len); + /* Send the challenge */ + + return send_request(c, "%d %s", CHALLENGE, buffer); +#endif +} - /* Convert the challenge from hexadecimal back to binary */ +bool challenge_h(connection_t *c, const char *request) { +#ifdef DISABLE_LEGACY + return false; +#else + if(!myself->connection->rsa) + return false; + + char buffer[MAX_STRING_SIZE]; + const size_t len = rsa_size(myself->connection->rsa); + size_t digestlen = digest_length(c->indigest); + char digest[digestlen]; + + if(sscanf(request, "%*d " MAX_STRING, buffer) != 1) { + logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s)", "CHALLENGE", c->name, c->hostname); + return false; + } + + /* Convert the challenge from hexadecimal back to binary */ + + int inlen = hex2bin(buffer, buffer, sizeof buffer); + + /* Check if the length of the challenge is all right */ + + if(inlen != len) { + logger(DEBUG_ALWAYS, LOG_ERR, "Possible intruder %s (%s): %s", c->name, c->hostname, "wrong challenge length"); + return false; + } - hex2bin(buffer,c->mychallenge,len); + /* Calculate the hash from the challenge we received */ - c->allow_request = CHAL_REPLY; + if(!digest_create(c->indigest, buffer, len, digest)) + return false; - /* Rest is done by send_chal_reply() */ - cp(); - return send_chal_reply(c); + /* Convert the hash to a hexadecimal formatted string */ + + bin2hex(digest, buffer, digestlen); + + /* Send the reply */ + + c->allow_request = CHAL_REPLY; + + return send_request(c, "%d %s", CHAL_REPLY, buffer); +#endif } -int send_chal_reply(connection_t *c) -{ - char hash[EVP_MAX_MD_SIZE*2+1]; - EVP_MD_CTX ctx; - cp(); - /* Calculate the hash from the challenge we received */ +bool chal_reply_h(connection_t *c, const char *request) { +#ifdef DISABLE_LEGACY + return false; +#else + char hishash[MAX_STRING_SIZE]; + + if(sscanf(request, "%*d " MAX_STRING, hishash) != 1) { + logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s)", "CHAL_REPLY", c->name, + c->hostname); + return false; + } - EVP_DigestInit(&ctx, c->indigest); - EVP_DigestUpdate(&ctx, c->mychallenge, RSA_size(myself->connection->rsa_key)); - EVP_DigestFinal(&ctx, hash, NULL); + /* Convert the hash to binary format */ - /* Convert the hash to a hexadecimal formatted string */ + int inlen = hex2bin(hishash, hishash, sizeof hishash); - bin2hex(hash,hash,c->indigest->md_size); - hash[c->indigest->md_size*2] = '\0'; + /* Check if the length of the hash is all right */ + + if(inlen != digest_length(c->outdigest)) { + logger(DEBUG_ALWAYS, LOG_ERR, "Possible intruder %s (%s): %s", c->name, c->hostname, "wrong challenge reply length"); + return false; + } + + + /* Verify the hash */ + + if(!digest_verify(c->outdigest, c->hischallenge, rsa_size(c->rsa), hishash)) { + logger(DEBUG_ALWAYS, LOG_ERR, "Possible intruder %s (%s): %s", c->name, c->hostname, "wrong challenge reply"); + return false; + } - /* Send the reply */ + /* Identity has now been positively verified. + Send an acknowledgement with the rest of the information needed. + */ - cp(); - return send_request(c, "%d %s", CHAL_REPLY, hash); + free(c->hischallenge); + c->hischallenge = NULL; + c->allow_request = ACK; + + return send_ack(c); +#endif +} + +static bool send_upgrade(connection_t *c) { +#ifdef DISABLE_LEGACY + return false; +#else + /* Special case when protocol_minor is 1: the other end is Ed25519 capable, + * but doesn't know our key yet. So send it now. */ + + char *pubkey = ecdsa_get_base64_public_key(myself->connection->ecdsa); + + if(!pubkey) + return false; + + bool result = send_request(c, "%d %s", ACK, pubkey); + free(pubkey); + return result; +#endif } -int chal_reply_h(connection_t *c) -{ - char hishash[MAX_STRING_SIZE]; - char myhash[EVP_MAX_MD_SIZE]; - EVP_MD_CTX ctx; - cp(); - if(sscanf(c->buffer, "%*d "MAX_STRING, hishash) != 1) - { - syslog(LOG_ERR, _("Got bad %s from %s (%s)"), "CHAL_REPLY", c->name, c->hostname); - return -1; - } - - /* Check if the length of the hash is all right */ - - if(strlen(hishash) != c->outdigest->md_size*2) - { - syslog(LOG_ERR, _("Possible intruder %s (%s): %s"), c->name, c->hostname, _("wrong challenge reply length")); - return -1; - } - - /* Convert the hash to binary format */ - - hex2bin(hishash, hishash, c->outdigest->md_size); - - /* Calculate the hash from the challenge we sent */ - - EVP_DigestInit(&ctx, c->outdigest); - EVP_DigestUpdate(&ctx, c->hischallenge, RSA_size(c->rsa_key)); - EVP_DigestFinal(&ctx, myhash, NULL); - - /* Verify the incoming hash with the calculated hash */ - - if(memcmp(hishash, myhash, c->outdigest->md_size)) - { - syslog(LOG_ERR, _("Possible intruder %s (%s): %s"), c->name, c->hostname, _("wrong challenge reply")); - if(debug_lvl >= DEBUG_SCARY_THINGS) - { - bin2hex(myhash, hishash, SHA_DIGEST_LENGTH); - hishash[SHA_DIGEST_LENGTH*2] = '\0'; - syslog(LOG_DEBUG, _("Expected challenge reply: %s"), hishash); - } - return -1; - } - - /* Identity has now been positively verified. - Send an acknowledgement with the rest of the information needed. - */ - - c->allow_request = ACK; - cp(); - return send_ack(c); +bool send_ack(connection_t *c) { + if(c->protocol_minor == 1) + return send_upgrade(c); + + /* ACK message contains rest of the information the other end needs + to create node_t and edge_t structures. */ + + struct timeval now; + bool choice; + + /* Estimate weight */ + + gettimeofday(&now, NULL); + c->estimated_weight = (now.tv_sec - c->start.tv_sec) * 1000 + (now.tv_usec - c->start.tv_usec) / 1000; + + /* Check some options */ + + if((get_config_bool(lookup_config(c->config_tree, "IndirectData"), &choice) && choice) || myself->options & OPTION_INDIRECT) + c->options |= OPTION_INDIRECT; + + if((get_config_bool(lookup_config(c->config_tree, "TCPOnly"), &choice) && choice) || myself->options & OPTION_TCPONLY) + c->options |= OPTION_TCPONLY | OPTION_INDIRECT; + + if(myself->options & OPTION_PMTU_DISCOVERY) + c->options |= OPTION_PMTU_DISCOVERY; + + choice = myself->options & OPTION_CLAMP_MSS; + get_config_bool(lookup_config(c->config_tree, "ClampMSS"), &choice); + if(choice) + c->options |= OPTION_CLAMP_MSS; + + if(!get_config_int(lookup_config(c->config_tree, "Weight"), &c->estimated_weight)) + get_config_int(lookup_config(config_tree, "Weight"), &c->estimated_weight); + + return send_request(c, "%d %s %d %x", ACK, myport, c->estimated_weight, (c->options & 0xffffff) | (experimental ? (PROT_MINOR << 24) : 0)); } -int send_ack(connection_t *c) -{ - /* ACK message contains rest of the information the other end needs - to create node_t and edge_t structures. */ - - int x; - struct timeval now; - cp(); - /* Estimate weight */ - - gettimeofday(&now, NULL); - c->estimated_weight = (now.tv_sec - c->start.tv_sec) * 1000 + (now.tv_usec - c->start.tv_usec) / 1000; - x = send_request(c, "%d %s %d %lx", ACK, myport, c->estimated_weight, c->options); - cp(); - return x; +static void send_everything(connection_t *c) { + /* Send all known subnets and edges */ + + if(disablebuggypeers) { + static struct { + vpn_packet_t pkt; + char pad[MAXBUFSIZE - MAXSIZE]; + } zeropkt; + + memset(&zeropkt, 0, sizeof zeropkt); + zeropkt.pkt.len = MAXBUFSIZE; + send_tcppacket(c, &zeropkt.pkt); + } + + if(tunnelserver) { + for splay_each(subnet_t, s, myself->subnet_tree) + send_add_subnet(c, s); + + return; + } + + for splay_each(node_t, n, node_tree) { + for splay_each(subnet_t, s, n->subnet_tree) + send_add_subnet(c, s); + + for splay_each(edge_t, e, n->edge_tree) + send_add_edge(c, e); + } } -void send_everything(connection_t *c) -{ - avl_node_t *node, *node2; - node_t *n; - subnet_t *s; - edge_t *e; - - /* Send all known subnets and edges */ - - for(node = node_tree->head; node; node = node->next) - { - n = (node_t *)node->data; - - for(node2 = n->subnet_tree->head; node2; node2 = node2->next) - { - s = (subnet_t *)node2->data; - send_add_subnet(c, s); - } - - for(node2 = n->edge_tree->head; node2; node2 = node2->next) - { - e = (edge_t *)node2->data; - send_add_edge(c, e); - } - } +static bool upgrade_h(connection_t *c, const char *request) { + char pubkey[MAX_STRING_SIZE]; + + if(sscanf(request, "%*d " MAX_STRING, pubkey) != 1) { + logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s)", "ACK", c->name, c->hostname); + return false; + } + + if(ecdsa_active(c->ecdsa) || read_ecdsa_public_key(c)) { + char *knownkey = ecdsa_get_base64_public_key(c->ecdsa); + bool different = strcmp(knownkey, pubkey); + free(knownkey); + if(different) { + logger(DEBUG_ALWAYS, LOG_ERR, "Already have an Ed25519 public key from %s (%s) which is different from the one presented now!", c->name, c->hostname); + return false; + } + logger(DEBUG_ALWAYS, LOG_INFO, "Already have Ed25519 public key from %s (%s), ignoring.", c->name, c->hostname); + c->allow_request = TERMREQ; + return send_termreq(c); + } + + c->ecdsa = ecdsa_set_base64_public_key(pubkey); + if(!c->ecdsa) { + logger(DEBUG_ALWAYS, LOG_INFO, "Got bad Ed25519 public key from %s (%s), not upgrading.", c->name, c->hostname); + return false; + } + + logger(DEBUG_ALWAYS, LOG_INFO, "Got Ed25519 public key from %s (%s), upgrading!", c->name, c->hostname); + append_config_file(c->name, "Ed25519PublicKey", pubkey); + c->allow_request = TERMREQ; + if(c->outgoing) + c->outgoing->timeout = 0; + return send_termreq(c); } -int ack_h(connection_t *c) -{ - char hisport[MAX_STRING_SIZE]; - char *hisaddress, *dummy; - int weight; - long int options; - node_t *n; - cp(); - if(sscanf(c->buffer, "%*d "MAX_STRING" %d %lx", hisport, &weight, &options) != 3) - { - syslog(LOG_ERR, _("Got bad %s from %s (%s)"), "ACK", c->name, c->hostname); - return -1; - } - - /* Check if we already have a node_t for him */ - - n = lookup_node(c->name); - - if(!n) - { - n = new_node(); - n->name = xstrdup(c->name); - node_add(n); - } - else - { - if(n->connection) - { - /* Oh dear, we already have a connection to this node. */ - if(debug_lvl >= DEBUG_CONNECTIONS) - syslog(LOG_DEBUG, _("Established a second connection with %s (%s), closing old connection"), n->name, n->hostname); - terminate_connection(n->connection, 0); - } - } - - n->connection = c; - c->node = n; - c->options |= options; - - /* Activate this connection */ - - c->allow_request = ALL; - c->status.active = 1; - - if(debug_lvl >= DEBUG_CONNECTIONS) - syslog(LOG_NOTICE, _("Connection with %s (%s) activated"), c->name, c->hostname); - - /* Send him everything we know */ - - send_everything(c); - - /* Create an edge_t for this connection */ - - c->edge = new_edge(); - cp(); - c->edge->from = myself; - c->edge->to = n; - sockaddr2str(&c->address, &hisaddress, &dummy); - c->edge->address = str2sockaddr(hisaddress, hisport); - free(hisaddress); - free(dummy); - c->edge->weight = (weight + c->estimated_weight) / 2; - c->edge->connection = c; - c->edge->options = c->options; - cp(); - edge_add(c->edge); - - cp(); - /* Notify everyone of the new edge */ - - send_add_edge(broadcast, c->edge); - - /* Run MST and SSSP algorithms */ - - graph(); - cp(); - return 0; +bool ack_h(connection_t *c, const char *request) { + if(c->protocol_minor == 1) + return upgrade_h(c, request); + + char hisport[MAX_STRING_SIZE]; + char *hisaddress; + int weight, mtu; + uint32_t options; + node_t *n; + bool choice; + + if(sscanf(request, "%*d " MAX_STRING " %d %x", hisport, &weight, &options) != 3) { + logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s)", "ACK", c->name, + c->hostname); + return false; + } + + /* Check if we already have a node_t for him */ + + n = lookup_node(c->name); + + if(!n) { + n = new_node(); + n->name = xstrdup(c->name); + node_add(n); + } else { + if(n->connection) { + /* Oh dear, we already have a connection to this node. */ + logger(DEBUG_CONNECTIONS, LOG_DEBUG, "Established a second connection with %s (%s), closing old connection", n->connection->name, n->connection->hostname); + + if(n->connection->outgoing) { + if(c->outgoing) + logger(DEBUG_ALWAYS, LOG_WARNING, "Two outgoing connections to the same node!"); + else + c->outgoing = n->connection->outgoing; + + n->connection->outgoing = NULL; + } + + terminate_connection(n->connection, false); + /* Run graph algorithm to purge key and make sure up/down scripts are rerun with new IP addresses and stuff */ + graph(); + } + } + + n->connection = c; + c->node = n; + if(!(c->options & options & OPTION_PMTU_DISCOVERY)) { + c->options &= ~OPTION_PMTU_DISCOVERY; + options &= ~OPTION_PMTU_DISCOVERY; + } + c->options |= options; + + if(get_config_int(lookup_config(c->config_tree, "PMTU"), &mtu) && mtu < n->mtu) + n->mtu = mtu; + + if(get_config_int(lookup_config(config_tree, "PMTU"), &mtu) && mtu < n->mtu) + n->mtu = mtu; + + if(get_config_bool(lookup_config(c->config_tree, "ClampMSS"), &choice)) { + if(choice) + c->options |= OPTION_CLAMP_MSS; + else + c->options &= ~OPTION_CLAMP_MSS; + } + + /* Activate this connection */ + + c->allow_request = ALL; + + logger(DEBUG_CONNECTIONS, LOG_NOTICE, "Connection with %s (%s) activated", c->name, + c->hostname); + + /* Send him everything we know */ + + send_everything(c); + + /* Create an edge_t for this connection */ + + c->edge = new_edge(); + c->edge->from = myself; + c->edge->to = n; + sockaddr2str(&c->address, &hisaddress, NULL); + c->edge->address = str2sockaddr(hisaddress, hisport); + free(hisaddress); + sockaddr_t local_sa; + socklen_t local_salen = sizeof local_sa; + if (getsockname(c->socket, &local_sa.sa, &local_salen) < 0) + logger(DEBUG_ALWAYS, LOG_WARNING, "Could not get local socket address for connection with %s", c->name); + else { + char *local_address; + sockaddr2str(&local_sa, &local_address, NULL); + c->edge->local_address = str2sockaddr(local_address, myport); + free(local_address); + } + c->edge->weight = (weight + c->estimated_weight) / 2; + c->edge->connection = c; + c->edge->options = c->options; + + edge_add(c->edge); + + /* Notify everyone of the new edge */ + + if(tunnelserver) + send_add_edge(c, c->edge); + else + send_add_edge(everyone, c->edge); + + /* Run MST and SSSP algorithms */ + + graph(); + + return true; }