/*
protocol_auth.c -- handle the meta-protocol, authentication
Copyright (C) 1999-2005 Ivo Timmermans,
- 2000-2013 Guus Sliepen <guus@tinc-vpn.org>
+ 2000-2016 Guus Sliepen <guus@tinc-vpn.org>
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
#include "netutl.h"
#include "node.h"
#include "protocol.h"
+#include "proxy.h"
#include "utils.h"
#include "xalloc.h"
-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(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)
- strcpy(s4req + 8, 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);
- strcpy(s5req + i, proxyuser);
- i += strlen(proxyuser);
- s5req[i++] = strlen(proxypass);
- strcpy(s5req + i, 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(LOG_ERR, "Address family %hx 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(LOG_ERR, "Proxy type not implemented yet");
- return false;
- case PROXY_EXEC:
- return true;
- default:
- logger(LOG_ERR, "Unknown proxy type");
- return false;
- }
-}
-
bool send_id(connection_t *c) {
- if(proxytype && c->outgoing)
- if(!send_proxyrequest(c))
- return false;
+ 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);
+ myself->connection->protocol_version);
}
bool id_h(connection_t *c) {
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);
+ c->hostname);
return false;
}
/* Check if identity is a valid name */
- if(!check_id(name)) {
+ if(!check_id(name) || !strcmp(name, myself->name)) {
logger(LOG_ERR, "Got bad %s from %s (%s): %s", "ID", c->name,
- c->hostname, "invalid name");
+ c->hostname, "invalid name");
return false;
}
if(c->outgoing) {
if(strcmp(c->name, name)) {
logger(LOG_ERR, "Peer %s is %s instead of %s", c->hostname, name,
- c->name);
+ c->name);
return false;
}
} else {
- if(c->name)
+ if(c->name) {
free(c->name);
+ }
+
c->name = xstrdup(name);
}
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);
+ c->name, c->hostname, c->protocol_version);
return false;
}
if(bypass_security) {
- if(!c->config_tree)
+ if(!c->config_tree) {
init_configuration(&c->config_tree);
+ }
+
c->allow_request = ACK;
+
+ if(!c->outgoing) {
+ send_id(c);
+ }
+
return send_ack(c);
}
if(!read_connection_config(c)) {
logger(LOG_ERR, "Peer %s had unknown identity (%s)", c->hostname,
- c->name);
+ c->name);
return false;
}
}
c->allow_request = METAKEY;
+ if(!c->outgoing) {
+ send_id(c);
+ }
+
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;
+}
+
bool send_metakey(connection_t *c) {
bool x;
/* Allocate buffers for the meta key */
char buffer[2 * len + 1];
-
+
c->outkey = xrealloc(c->outkey, len);
- if(!c->outctx)
- c->outctx = xmalloc_and_zero(sizeof(*c->outctx));
+ if(!c->outctx) {
+ c->outctx = EVP_CIPHER_CTX_new();
+
+ if(!c->outctx) {
+ abort();
+ }
+ }
/* Copy random data to the buffer */
- RAND_bytes((unsigned char *)c->outkey, len);
+ 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:
bin2hex(c->outkey, buffer, len);
buffer[len * 2] = '\0';
logger(LOG_DEBUG, "Generated random meta key (unencrypted): %s",
- buffer);
+ buffer);
}
/* Encrypt the random data
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));
+ c->name, c->hostname, ERR_error_string(ERR_get_error(), NULL));
return false;
}
/* 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);
+ 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 - c->outcipher->key_len,
- (unsigned char *)c->outkey + len - c->outcipher->key_len -
- c->outcipher->iv_len)) {
+ (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));
+ c->name, c->hostname, ERR_error_string(ERR_get_error(), NULL));
return false;
}
+ c->outbudget = byte_budget(c->outcipher);
c->status.encryptout = true;
}
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);
+ c->hostname);
return false;
}
/* Check if the length of the meta key is all right */
- if(strlen(buffer) != len * 2) {
+ if(strlen(buffer) != (size_t)len * 2) {
logger(LOG_ERR, "Possible intruder %s (%s): %s", c->name, c->hostname, "wrong keylength");
return false;
}
c->inkey = xrealloc(c->inkey, len);
- if(!c->inctx)
- c->inctx = xmalloc_and_zero(sizeof(*c->inctx));
+ if(!c->inctx) {
+ c->inctx = EVP_CIPHER_CTX_new();
+
+ if(!c->inctx) {
+ abort();
+ }
+ }
/* Convert the challenge from hexadecimal back to binary */
/* 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() */
+ 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));
+ c->name, c->hostname, ERR_error_string(ERR_get_error(), NULL));
return false;
}
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 - c->incipher->key_len,
- (unsigned char *)c->inkey + len - c->incipher->key_len -
- c->incipher->iv_len)) {
+ (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));
+ 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;
+ logger(LOG_ERR, "%s (%s) uses null cipher!", c->name, c->hostname);
+ return false;
}
c->inmaclength = maclength;
return false;
}
- if(c->inmaclength > c->indigest->md_size || c->inmaclength < 0) {
+ 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;
+ logger(LOG_ERR, "%s (%s) uses null digest!", c->name, c->hostname);
+ return false;
}
c->incompression = compression;
/* Copy random data to the buffer */
- RAND_bytes((unsigned char *)c->hischallenge, len);
+ 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.
+ }
/* Convert to hex */
if(sscanf(c->buffer, "%*d " MAX_STRING, buffer) != 1) {
logger(LOG_ERR, "Got bad %s from %s (%s)", "CHALLENGE", c->name,
- c->hostname);
+ c->hostname);
return false;
}
/* Check if the length of the challenge is all right */
- if(strlen(buffer) != len * 2) {
+ if(strlen(buffer) != (size_t)len * 2) {
logger(LOG_ERR, "Possible intruder %s (%s): %s", c->name,
- c->hostname, "wrong challenge length");
+ c->hostname, "wrong challenge length");
return false;
}
/* Rest is done by send_chal_reply() */
- return send_chal_reply(c);
+ if(c->outgoing) {
+ return send_chal_reply(c);
+ } else {
+ return true;
+ }
}
bool send_chal_reply(connection_t *c) {
char hash[EVP_MAX_MD_SIZE * 2 + 1];
- EVP_MD_CTX ctx;
+ EVP_MD_CTX *ctx;
/* Calculate the hash from the challenge we received */
- if(!EVP_DigestInit(&ctx, c->indigest)
- || !EVP_DigestUpdate(&ctx, c->mychallenge, RSA_size(myself->connection->rsa_key))
- || !EVP_DigestFinal(&ctx, (unsigned char *)hash, NULL)) {
+ ctx = EVP_MD_CTX_create();
+
+ 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));
+ c->name, c->hostname, ERR_error_string(ERR_get_error(), NULL));
return false;
}
+ EVP_MD_CTX_destroy(ctx);
+
/* Convert the hash to a hexadecimal formatted string */
- bin2hex(hash, hash, c->indigest->md_size);
- hash[c->indigest->md_size * 2] = '\0';
+ bin2hex(hash, hash, EVP_MD_size(c->indigest));
+ hash[EVP_MD_size(c->indigest) * 2] = '\0';
/* Send the reply */
bool chal_reply_h(connection_t *c) {
char hishash[MAX_STRING_SIZE];
char myhash[EVP_MAX_MD_SIZE];
- EVP_MD_CTX ctx;
+ 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);
+ c->hostname);
return false;
}
/* Check if the length of the hash is all right */
- if(strlen(hishash) != c->outdigest->md_size * 2) {
+ if(strlen(hishash) != (size_t)EVP_MD_size(c->outdigest) * 2) {
logger(LOG_ERR, "Possible intruder %s (%s): %s", c->name,
- c->hostname, "wrong challenge reply length");
+ c->hostname, "wrong challenge reply length");
return false;
}
/* Convert the hash to binary format */
- if(!hex2bin(hishash, hishash, c->outdigest->md_size)) {
+ 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 */
- if(!EVP_DigestInit(&ctx, c->outdigest)
- || !EVP_DigestUpdate(&ctx, c->hischallenge, RSA_size(c->rsa_key))
- || !EVP_DigestFinal(&ctx, (unsigned char *)myhash, NULL)) {
+ 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));
+ 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, c->outdigest->md_size)) {
+ if(memcmp(hishash, myhash, EVP_MD_size(c->outdigest))) {
logger(LOG_ERR, "Possible intruder %s (%s): %s", c->name,
- c->hostname, "wrong challenge reply");
+ c->hostname, "wrong challenge reply");
ifdebug(SCARY_THINGS) {
bin2hex(myhash, hishash, SHA_DIGEST_LENGTH);
c->allow_request = ACK;
+ if(!c->outgoing) {
+ send_chal_reply(c);
+ }
+
return send_ack(c);
}
/* Check some options */
- if((get_config_bool(lookup_config(c->config_tree, "IndirectData"), &choice) && choice) || myself->options & OPTION_INDIRECT)
+ 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)
+ 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)
+ if(myself->options & OPTION_PMTU_DISCOVERY && !(c->options & OPTION_TCPONLY)) {
c->options |= OPTION_PMTU_DISCOVERY;
+ }
choice = myself->options & OPTION_CLAMP_MSS;
get_config_bool(lookup_config(c->config_tree, "ClampMSS"), &choice);
- if(choice)
+
+ if(choice) {
c->options |= OPTION_CLAMP_MSS;
+ }
get_config_int(lookup_config(c->config_tree, "Weight"), &c->estimated_weight);
bool ack_h(connection_t *c) {
char hisport[MAX_STRING_SIZE];
- char *hisaddress;
int weight, mtu;
uint32_t options;
node_t *n;
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);
+ c->hostname);
return false;
}
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);
+ 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)
+ 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)
+ 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)
+ if(choice) {
c->options |= OPTION_CLAMP_MSS;
- else
+ } else {
c->options &= ~OPTION_CLAMP_MSS;
+ }
}
/* Activate this connection */
c->status.active = true;
ifdebug(CONNECTIONS) logger(LOG_NOTICE, "Connection with %s (%s) activated", c->name,
- c->hostname);
+ c->hostname);
/* Send him everything we know */
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);
+ 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;
/* Notify everyone of the new edge */
- if(tunnelserver)
+ if(tunnelserver) {
send_add_edge(c, c->edge);
- else
+ } else {
send_add_edge(everyone, c->edge);
+ }
/* Run MST and SSSP algorithms */
projects / oweals / tinc.git / blobdiff