X-Git-Url: https://tinc-vpn.org/git/browse?p=tinc;a=blobdiff_plain;f=src%2Fprotocol_auth.c;h=1623e75e4992307f0b460e78f66a8f870301c689;hp=5f2dcaa2d67f32594ebfb34fddeaea3b823ac1a0;hb=5dec1c25713a19c49fcbb885200184a9682ef175;hpb=258bf7ea0fe69bae395a084843ba59b9770199f1 diff --git a/src/protocol_auth.c b/src/protocol_auth.c index 5f2dcaa2..1623e75e 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) 1999-2005 Ivo Timmermans, - 2000-2012 Guus Sliepen + 2000-2013 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 @@ -27,10 +27,12 @@ #include "cipher.h" #include "crypto.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" @@ -41,6 +43,8 @@ #include "utils.h" #include "xalloc.h" +ecdsa_t *invitation_key = NULL; + static bool send_proxyrequest(connection_t *c) { switch(proxytype) { case PROXY_HTTP: { @@ -133,7 +137,7 @@ bool send_id(connection_t *c) { int minor = 0; if(experimental) { - if(c->config_tree && !read_ecdsa_public_key(c)) + if(c->outgoing && !read_ecdsa_public_key(c)) minor = 1; else minor = myself->connection->protocol_minor; @@ -146,6 +150,108 @@ bool send_id(connection_t *c) { return send_request(c, "%d %s %d.%d", ID, myself->connection->name, myself->connection->protocol_major, minor); } +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, "ECDSAPublicKey = %s\n", data); + fclose(f); + + logger(DEBUG_CONNECTIONS, LOG_INFO, "Key succesfully received from %s (%s)", c->name, c->hostname); + sptps_send_record(&c->sptps, 2, data, 0); + return true; +} + +static bool receive_invitation_sptps(void *handle, uint8_t type, const char *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; + + char cookie[25]; + b64encode_urlsafe(data, cookie, 18); + + 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]; @@ -168,6 +274,31 @@ bool id_h(connection_t *c, const char *request) { 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)) { @@ -194,7 +325,7 @@ bool id_h(connection_t *c, const char *request) { 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); + c->name, c->hostname, c->protocol_major, c->protocol_minor); return false; } @@ -216,15 +347,21 @@ bool id_h(connection_t *c, const char *request) { return false; } - if(experimental && c->protocol_minor >= 2) { - if(!read_ecdsa_public_key(c)) - return false; - } + if(experimental) + read_ecdsa_public_key(c); } else { - if(c->protocol_minor && !ecdsa_active(&c->ecdsa)) + if(c->protocol_minor && !ecdsa_active(c->ecdsa)) c->protocol_minor = 1; } + /* Forbid version rollback for nodes whose ECDSA key we know */ + + if(ecdsa_active(c->ecdsa) && c->protocol_minor < 2) { + 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) { @@ -246,13 +383,13 @@ bool send_metakey(connection_t *c) { if(!read_rsa_public_key(c)) return false; - if(!cipher_open_blowfish_ofb(&c->outcipher)) + if(!(c->outcipher = cipher_open_blowfish_ofb())) return false; - if(!digest_open_sha1(&c->outdigest, -1)) + if(!(c->outdigest = digest_open_sha1(-1))) return false; - size_t len = rsa_size(&c->rsa); + size_t len = rsa_size(c->rsa); char key[len]; char enckey[len]; char hexkey[2 * len + 1]; @@ -273,7 +410,8 @@ bool send_metakey(connection_t *c) { key[0] &= 0x7F; - cipher_set_key_from_rsa(&c->outcipher, key, len, true); + if(!cipher_set_key_from_rsa(c->outcipher, key, len, true)) + return false; if(debug_level >= DEBUG_SCARY_THINGS) { bin2hex(key, hexkey, len); @@ -287,7 +425,7 @@ bool send_metakey(connection_t *c) { with a length equal to that of the modulus of the RSA key. */ - if(!rsa_public_encrypt(&c->rsa, key, len, enckey)) { + 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; } @@ -299,8 +437,8 @@ bool send_metakey(connection_t *c) { /* 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, + cipher_get_nid(c->outcipher), + digest_get_nid(c->outdigest), c->outmaclength, c->outcompression, hexkey); c->status.encryptout = true; @@ -310,7 +448,7 @@ bool send_metakey(connection_t *c) { bool metakey_h(connection_t *c, const char *request) { char hexkey[MAX_STRING_SIZE]; int cipher, digest, maclength, compression; - size_t len = rsa_size(&myself->connection->rsa); + size_t len = rsa_size(myself->connection->rsa); char enckey[len]; char key[len]; @@ -332,7 +470,7 @@ bool metakey_h(connection_t *c, const char *request) { /* Decrypt the meta key */ - if(!rsa_private_decrypt(&myself->connection->rsa, enckey, len, 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; } @@ -344,12 +482,12 @@ bool metakey_h(connection_t *c, const char *request) { /* Check and lookup cipher and digest algorithms */ - if(!cipher_open_by_nid(&c->incipher, cipher) || !cipher_set_key_from_rsa(&c->incipher, key, len, false)) { + 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; } - if(!digest_open_by_nid(&c->indigest, digest, -1)) { + 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; } @@ -362,7 +500,7 @@ bool metakey_h(connection_t *c, const char *request) { } bool send_challenge(connection_t *c) { - size_t len = rsa_size(&c->rsa); + size_t len = rsa_size(c->rsa); char buffer[len * 2 + 1]; if(!c->hischallenge) @@ -383,8 +521,8 @@ bool send_challenge(connection_t *c) { bool challenge_h(connection_t *c, const char *request) { char buffer[MAX_STRING_SIZE]; - size_t len = rsa_size(&myself->connection->rsa); - size_t digestlen = digest_length(&c->indigest); + 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) { @@ -403,11 +541,10 @@ bool challenge_h(connection_t *c, const char *request) { return false; } - c->allow_request = CHAL_REPLY; - /* Calculate the hash from the challenge we received */ - digest_create(&c->indigest, buffer, len, digest); + if(!digest_create(c->indigest, buffer, len, digest)) + return false; /* Convert the hash to a hexadecimal formatted string */ @@ -415,6 +552,8 @@ bool challenge_h(connection_t *c, const char *request) { /* Send the reply */ + c->allow_request = CHAL_REPLY; + return send_request(c, "%d %s", CHAL_REPLY, buffer); } @@ -433,7 +572,7 @@ bool chal_reply_h(connection_t *c, const char *request) { /* Check if the length of the hash is all right */ - if(inlen != digest_length(&c->outdigest)) { + 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; } @@ -441,7 +580,7 @@ bool chal_reply_h(connection_t *c, const char *request) { /* Verify the hash */ - if(!digest_verify(&c->outdigest, c->hischallenge, rsa_size(&c->rsa), hishash)) { + 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; } @@ -461,7 +600,7 @@ static bool send_upgrade(connection_t *c) { /* Special case when protocol_minor is 1: the other end is ECDSA capable, * but doesn't know our key yet. So send it now. */ - char *pubkey = ecdsa_get_base64_public_key(&myself->connection->ecdsa); + char *pubkey = ecdsa_get_base64_public_key(myself->connection->ecdsa); if(!pubkey) return false; @@ -545,7 +684,7 @@ static bool upgrade_h(connection_t *c, const char *request) { return false; } - if(ecdsa_active(&c->ecdsa) || read_ecdsa_public_key(c)) { + if(ecdsa_active(c->ecdsa) || read_ecdsa_public_key(c)) { logger(DEBUG_ALWAYS, LOG_INFO, "Already have ECDSA public key from %s (%s), not upgrading.", c->name, c->hostname); return false; }