X-Git-Url: https://www.tinc-vpn.org/git/browse?p=tinc;a=blobdiff_plain;f=src%2Fprotocol_auth.c;h=0d21be091bb6b2b0f45cc2ec1400b3060e87a305;hp=cbe0958da277e0458517cb90dd629c0fae53be6d;hb=3fae14fae5a347823679ef694ab630b4991a201d;hpb=3c5655f59e85d312d11fa04489123e604920f95b diff --git a/src/protocol_auth.c b/src/protocol_auth.c index cbe0958d..0d21be09 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, + 2000-2016 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 @@ -13,600 +13,655 @@ 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 1.1.4.5 2002/03/22 13:31:18 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 "system.h" #include #include +#include #include -#ifndef HAVE_RAND_PSEUDO_BYTES -#define RAND_pseudo_bytes RAND_bytes -#endif - +#include "avl_tree.h" #include "conf.h" -#include "net.h" -#include "netutl.h" -#include "protocol.h" -#include "meta.h" #include "connection.h" -#include "node.h" #include "edge.h" #include "graph.h" +#include "logger.h" +#include "meta.h" +#include "net.h" +#include "netutl.h" +#include "node.h" +#include "protocol.h" +#include "proxy.h" +#include "utils.h" +#include "xalloc.h" -#include "system.h" +bool send_id(connection_t *c) { + if(proxytype && c->outgoing && !c->status.proxy_passed) { + return send_proxyrequest(c); + } + + return send_request(c, "%d %s %d", ID, myself->connection->name, + myself->connection->protocol_version); +} + +bool id_h(connection_t *c) { + char name[MAX_STRING_SIZE]; + + if(sscanf(c->buffer, "%*d " MAX_STRING " %d", name, &c->protocol_version) != 2) { + logger(LOG_ERR, "Got bad %s from %s (%s)", "ID", c->name, + c->hostname); + return false; + } + + /* Check if identity is a valid name */ + + if(!check_id(name)) { + logger(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(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_version != myself->connection->protocol_version) { + logger(LOG_ERR, "Peer %s (%s) uses incompatible version %d", + c->name, c->hostname, c->protocol_version); + return false; + } + + 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); -int send_id(connection_t *c) -{ -cp - return send_request(c, "%d %s %d", ID, myself->connection->name, myself->connection->protocol_version); + if(!read_connection_config(c)) { + logger(LOG_ERR, "Peer %s had unknown identity (%s)", c->hostname, + c->name); + return false; + } + } + + if(!read_rsa_public_key(c)) { + return false; + } + + c->allow_request = METAKEY; + + return send_metakey(c); } -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); - - if((bla = read_connection_config(c))) - { - 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 uint64_t byte_budget(const EVP_CIPHER *cipher) { + /* Hopefully some failsafe way to calculate the maximum amount of bytes to + send/receive with a given cipher before we might run into birthday paradox + attacks. Because we might use different modes, the block size of the mode + might be 1 byte. In that case, use the IV length. Ensure the whole thing + is limited to what can be represented with a 64 bits integer. + */ + + int ivlen = EVP_CIPHER_iv_length(cipher); + int blklen = EVP_CIPHER_block_size(cipher); + int len = blklen > 1 ? blklen : ivlen > 1 ? ivlen : 8; + int bits = len * 4 - 1; + return bits < 64 ? UINT64_C(1) << bits : UINT64_MAX; } -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; +bool send_metakey(connection_t *c) { + bool x; + + int len = RSA_size(c->rsa_key); + + /* Allocate buffers for the meta key */ + + char buffer[2 * len + 1]; + + c->outkey = xrealloc(c->outkey, len); + + if(!c->outctx) { + c->outctx = EVP_CIPHER_CTX_new(); + + if(!c->outctx) { + abort(); + } + } + + /* Copy random data to the buffer */ + + if(1 != RAND_bytes((unsigned char *)c->outkey, len)) { + int err = ERR_get_error(); + logger(LOG_ERR, "Failed to generate meta key (%s)", ERR_error_string(err, NULL)); + return false; + } + + + /* 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; + + ifdebug(SCARY_THINGS) { + bin2hex(c->outkey, buffer, len); + buffer[len * 2] = '\0'; + logger(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, (unsigned char *)c->outkey, (unsigned char *)buffer, c->rsa_key, RSA_NO_PADDING) != len) { + logger(LOG_ERR, "Error during encryption of meta key for %s (%s): %s", + c->name, c->hostname, ERR_error_string(ERR_get_error(), NULL)); + return false; + } + + /* 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 ? EVP_CIPHER_nid(c->outcipher) : 0, + c->outdigest ? EVP_MD_type(c->outdigest) : 0, c->outmaclength, + c->outcompression, buffer); + + /* Further outgoing requests are encrypted with the key we just generated */ + + if(c->outcipher) { + if(!EVP_EncryptInit(c->outctx, c->outcipher, + (unsigned char *)c->outkey + len - EVP_CIPHER_key_length(c->outcipher), + (unsigned char *)c->outkey + len - EVP_CIPHER_key_length(c->outcipher) - + EVP_CIPHER_iv_length(c->outcipher))) { + logger(LOG_ERR, "Error during initialisation of cipher for %s (%s): %s", + c->name, c->hostname, ERR_error_string(ERR_get_error(), NULL)); + return false; + } + + c->outbudget = byte_budget(c->outcipher); + c->status.encryptout = true; + } + + return x; } -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 metakey_h(connection_t *c) { + char buffer[MAX_STRING_SIZE]; + int cipher, digest, maclength, compression; + int len; + + if(sscanf(c->buffer, "%*d %d %d %d %d " MAX_STRING, &cipher, &digest, &maclength, &compression, buffer) != 5) { + logger(LOG_ERR, "Got bad %s from %s (%s)", "METAKEY", c->name, + c->hostname); + return false; + } + + len = RSA_size(myself->connection->rsa_key); + + /* Check if the length of the meta key is all right */ + + if(strlen(buffer) != len * 2) { + logger(LOG_ERR, "Possible intruder %s (%s): %s", c->name, c->hostname, "wrong keylength"); + return false; + } + + /* Allocate buffers for the meta key */ + + c->inkey = xrealloc(c->inkey, len); + + if(!c->inctx) { + c->inctx = EVP_CIPHER_CTX_new(); + + if(!c->inctx) { + abort(); + } + } + + /* Convert the challenge from hexadecimal back to binary */ + + if(!hex2bin(buffer, buffer, len)) { + logger(LOG_ERR, "Got bad %s from %s(%s): %s", "METAKEY", c->name, c->hostname, "invalid key"); + return false; + } + + /* Decrypt the meta key */ + + if(RSA_private_decrypt(len, (unsigned char *)buffer, (unsigned char *)c->inkey, myself->connection->rsa_key, RSA_NO_PADDING) != len) { /* See challenge() */ + logger(LOG_ERR, "Error during decryption of meta key for %s (%s): %s", + c->name, c->hostname, ERR_error_string(ERR_get_error(), NULL)); + return false; + } + + ifdebug(SCARY_THINGS) { + bin2hex(c->inkey, buffer, len); + buffer[len * 2] = '\0'; + logger(LOG_DEBUG, "Received random meta key (unencrypted): %s", buffer); + } + + /* All incoming requests will now be encrypted. */ + + /* Check and lookup cipher and digest algorithms */ + + if(cipher) { + c->incipher = EVP_get_cipherbynid(cipher); + + if(!c->incipher) { + logger(LOG_ERR, "%s (%s) uses unknown cipher!", c->name, c->hostname); + return false; + } + + if(!EVP_DecryptInit(c->inctx, c->incipher, + (unsigned char *)c->inkey + len - EVP_CIPHER_key_length(c->incipher), + (unsigned char *)c->inkey + len - EVP_CIPHER_key_length(c->incipher) - + EVP_CIPHER_iv_length(c->incipher))) { + logger(LOG_ERR, "Error during initialisation of cipher from %s (%s): %s", + c->name, c->hostname, ERR_error_string(ERR_get_error(), NULL)); + return false; + } + + c->inbudget = byte_budget(c->incipher); + c->status.decryptin = true; + } else { + c->incipher = NULL; + } + + c->inmaclength = maclength; + + if(digest) { + c->indigest = EVP_get_digestbynid(digest); + + if(!c->indigest) { + logger(LOG_ERR, "Node %s (%s) uses unknown digest!", c->name, c->hostname); + return false; + } + + if(c->inmaclength > EVP_MD_size(c->indigest) || c->inmaclength < 0) { + logger(LOG_ERR, "%s (%s) uses bogus MAC length!", c->name, c->hostname); + return false; + } + } else { + c->indigest = NULL; + } + + c->incompression = compression; + + c->allow_request = CHALLENGE; + + return send_challenge(c); } -int send_challenge(connection_t *c) -{ - char buffer[MAX_STRING_SIZE]; - int len, x; -cp - /* CHECKME: what is most reasonable value for len? */ +bool send_challenge(connection_t *c) { + /* CHECKME: what is most reasonable value for len? */ - len = RSA_size(c->rsa_key); + int len = RSA_size(c->rsa_key); - /* Allocate buffers for the challenge */ + /* Allocate buffers for the challenge */ - if(!c->hischallenge) - c->hischallenge = xmalloc(len); -cp - /* Copy random data to the buffer */ + char buffer[2 * len + 1]; - RAND_bytes(c->hischallenge, len); + c->hischallenge = xrealloc(c->hischallenge, len); + + /* Copy random data to the buffer */ + + if(1 != RAND_bytes((unsigned char *)c->hischallenge, len)) { + int err = ERR_get_error(); + logger(LOG_ERR, "Failed to generate challenge (%s)", ERR_error_string(err, NULL)); + return false; // Do not send predictable challenges, let connection attempt fail. + } -cp - /* Convert to hex */ + /* Convert to hex */ - bin2hex(c->hischallenge, buffer, len); - buffer[len*2] = '\0'; + bin2hex(c->hischallenge, buffer, len); + buffer[len * 2] = '\0'; -cp - /* Send the challenge */ + /* Send the challenge */ - x = send_request(c, "%d %s", CHALLENGE, buffer); -cp - return x; + return send_request(c, "%d %s", CHALLENGE, buffer); } -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 challenge_h(connection_t *c) { + char buffer[MAX_STRING_SIZE]; + int len; - len = RSA_size(myself->connection->rsa_key); + if(sscanf(c->buffer, "%*d " MAX_STRING, buffer) != 1) { + logger(LOG_ERR, "Got bad %s from %s (%s)", "CHALLENGE", c->name, + c->hostname); + return false; + } + + len = RSA_size(myself->connection->rsa_key); + + /* Check if the length of the challenge is all right */ - /* Check if the length of the challenge is all right */ + if(strlen(buffer) != len * 2) { + logger(LOG_ERR, "Possible intruder %s (%s): %s", c->name, + c->hostname, "wrong challenge length"); + return false; + } - if(strlen(buffer) != len*2) - { - syslog(LOG_ERR, _("Possible intruder %s (%s): %s"), c->name, c->hostname, "wrong challenge length"); - return -1; - } + /* Allocate buffers for the challenge */ - /* Allocate buffers for the challenge */ + c->mychallenge = xrealloc(c->mychallenge, len); - if(!c->mychallenge) - c->mychallenge = xmalloc(len); + /* Convert the challenge from hexadecimal back to binary */ - /* Convert the challenge from hexadecimal back to binary */ + if(!hex2bin(buffer, c->mychallenge, len)) { + logger(LOG_ERR, "Got bad %s from %s(%s): %s", "CHALLENGE", c->name, c->hostname, "invalid challenge"); + return false; + } - hex2bin(buffer,c->mychallenge,len); + c->allow_request = CHAL_REPLY; - c->allow_request = CHAL_REPLY; + /* Rest is done by send_chal_reply() */ - /* Rest is done by send_chal_reply() */ -cp - return send_chal_reply(c); + return send_chal_reply(c); } -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 send_chal_reply(connection_t *c) { + char hash[EVP_MAX_MD_SIZE * 2 + 1]; + EVP_MD_CTX *ctx; + + /* Calculate the hash from the challenge we received */ - EVP_DigestInit(&ctx, c->indigest); - EVP_DigestUpdate(&ctx, c->mychallenge, RSA_size(myself->connection->rsa_key)); - EVP_DigestFinal(&ctx, hash, NULL); + ctx = EVP_MD_CTX_create(); - /* Convert the hash to a hexadecimal formatted string */ + if(!ctx) { + abort(); + } + + if(!EVP_DigestInit(ctx, c->indigest) + || !EVP_DigestUpdate(ctx, c->mychallenge, RSA_size(myself->connection->rsa_key)) + || !EVP_DigestFinal(ctx, (unsigned char *)hash, NULL)) { + EVP_MD_CTX_destroy(ctx); + logger(LOG_ERR, "Error during calculation of response for %s (%s): %s", + c->name, c->hostname, ERR_error_string(ERR_get_error(), NULL)); + return false; + } - bin2hex(hash,hash,c->indigest->md_size); - hash[c->indigest->md_size*2] = '\0'; + EVP_MD_CTX_destroy(ctx); - /* Send the reply */ + /* Convert the hash to a hexadecimal formatted string */ -cp - return send_request(c, "%d %s", CHAL_REPLY, hash); + bin2hex(hash, hash, EVP_MD_size(c->indigest)); + hash[EVP_MD_size(c->indigest) * 2] = '\0'; + + /* Send the reply */ + + return send_request(c, "%d %s", CHAL_REPLY, hash); } -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 chal_reply_h(connection_t *c) { + char hishash[MAX_STRING_SIZE]; + char myhash[EVP_MAX_MD_SIZE]; + EVP_MD_CTX *ctx; + + if(sscanf(c->buffer, "%*d " MAX_STRING, hishash) != 1) { + logger(LOG_ERR, "Got bad %s from %s (%s)", "CHAL_REPLY", c->name, + c->hostname); + return false; + } + + /* Check if the length of the hash is all right */ + + if(strlen(hishash) != EVP_MD_size(c->outdigest) * 2) { + logger(LOG_ERR, "Possible intruder %s (%s): %s", c->name, + c->hostname, "wrong challenge reply length"); + return false; + } + + /* Convert the hash to binary format */ + + if(!hex2bin(hishash, hishash, EVP_MD_size(c->outdigest))) { + logger(LOG_ERR, "Got bad %s from %s(%s): %s", "CHAL_REPLY", c->name, c->hostname, "invalid hash"); + return false; + } + + /* Calculate the hash from the challenge we sent */ + + ctx = EVP_MD_CTX_create(); + + if(!ctx) { + abort(); + } + + if(!EVP_DigestInit(ctx, c->outdigest) + || !EVP_DigestUpdate(ctx, c->hischallenge, RSA_size(c->rsa_key)) + || !EVP_DigestFinal(ctx, (unsigned char *)myhash, NULL)) { + EVP_MD_CTX_destroy(ctx); + logger(LOG_ERR, "Error during calculation of response from %s (%s): %s", + c->name, c->hostname, ERR_error_string(ERR_get_error(), NULL)); + return false; + } + + EVP_MD_CTX_destroy(ctx); + + /* Verify the incoming hash with the calculated hash */ + + if(memcmp(hishash, myhash, EVP_MD_size(c->outdigest))) { + logger(LOG_ERR, "Possible intruder %s (%s): %s", c->name, + c->hostname, "wrong challenge reply"); + + ifdebug(SCARY_THINGS) { + bin2hex(myhash, hishash, SHA_DIGEST_LENGTH); + hishash[SHA_DIGEST_LENGTH * 2] = '\0'; + logger(LOG_DEBUG, "Expected challenge reply: %s", hishash); + } + + return false; + } + + /* Identity has now been positively verified. + Send an acknowledgement with the rest of the information needed. + */ + + c->allow_request = ACK; + + return send_ack(c); } -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; - char *address, *port; - 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; - sockaddr2str(&c->address, &address, &port); - x = send_request(c, "%d %s %s %s %d %lx", ACK, myport, address, port, c->estimated_weight, c->options); - free(address); - free(port); -cp - return x; +bool send_ack(connection_t *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; + } + + get_config_int(lookup_config(c->config_tree, "Weight"), &c->estimated_weight); + + return send_request(c, "%d %s %d %x", ACK, myport, c->estimated_weight, c->options); } -void send_everything(connection_t *c) -{ - avl_node_t *node, *node2; - node_t *n; - subnet_t *s; - edge_t *e; - - /* Send all known subnets */ - - 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); - } - } - - /* Send all known edges */ - - for(node = edge_tree->head; node; node = node->next) - { - e = (edge_t *)node->data; - - if(e == c->edge) - continue; - - send_add_edge(c, e); - } +static 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 */ + + if(tunnelserver) { + for(node = myself->subnet_tree->head; node; node = node->next) { + s = node->data; + send_add_subnet(c, s); + } + + return; + } + + for(node = node_tree->head; node; node = node->next) { + n = node->data; + + for(node2 = n->subnet_tree->head; node2; node2 = node2->next) { + s = node2->data; + send_add_subnet(c, s); + } + + for(node2 = n->edge_tree->head; node2; node2 = node2->next) { + e = node2->data; + send_add_edge(c, e); + } + } } -int ack_h(connection_t *c) -{ - char myaddress[MAX_STRING_SIZE]; - char hisport[MAX_STRING_SIZE]; - char *hisaddress, *dummy; - int weight; - long int options; - node_t *n; - connection_t *other; - avl_node_t *node; -cp - if(sscanf(c->buffer, "%*d "MAX_STRING" "MAX_STRING" %d %lx", hisport, myaddress, &weight, &options) != 4) - { - 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); - } - - /* FIXME: check if information in existing node matches that of the other end of this connection */ - } - - n->connection = c; - c->node = n; - c->options |= options; - - /* Create an edge_t for this connection */ - - c->edge = new_edge(); -cp - c->edge->from.node = myself; -// c->edge->from.tcpaddress = str2sockaddr(address, port); - c->edge->from.udpaddress = str2sockaddr(myaddress, myport); - c->edge->to.node = n; -// c->edge->to.tcpaddress = c->address; - sockaddr2str(&c->address, &hisaddress, &dummy); - c->edge->to.udpaddress = 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); - - /* 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); - -cp - /* Send him everything we know */ - - send_everything(c); - - /* Notify others of this connection */ - - for(node = connection_tree->head; node; node = node->next) - { - other = (connection_t *)node->data; - - if(other->status.active && other != c) - send_add_edge(other, c->edge); - } - - /* Run MST and SSSP algorithms */ - - graph(); - - /* Succesful connection, reset timeout if this is an outgoing connection. */ - - if(c->outgoing) - c->outgoing->timeout = 0; -cp - return 0; +bool ack_h(connection_t *c) { + char hisport[MAX_STRING_SIZE]; + int weight, mtu; + uint32_t options; + node_t *n; + bool choice; + + if(sscanf(c->buffer, "%*d " MAX_STRING " %d %x", hisport, &weight, &options) != 3) { + logger(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. */ + ifdebug(CONNECTIONS) logger(LOG_DEBUG, "Established a second connection with %s (%s), closing old connection", + n->name, n->hostname); + 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; + c->status.active = true; + + ifdebug(CONNECTIONS) logger(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; + sockaddrcpy(&c->edge->address, &c->address); + sockaddr_setport(&c->edge->address, hisport); + 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; }