Add ability to use proxies to connect to hostnames when there is no nameserver.

[oweals/tinc.git] / src / protocol_auth.c

diff --git a/src/protocol_auth.c b/src/protocol_auth.c
index 06735dcf87c27e4db30a096dd1a27d5eb3586ffc..e54fe231ac39c70bed677ea2d339c37640aa1a4d 100644 (file)
--- 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,
-                  2000-2010 Guus Sliepen <guus@tinc-vpn.org>
+                  2000-2014 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
@@ -31,14 +31,20 @@
 #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"
 
 bool send_id(connection_t *c) {
+       if(proxytype && c->outgoing)
+               if(!send_proxyrequest(c))
+                       return false;
+
        return send_request(c, "%d %s %d", ID, myself->connection->name,
                                                myself->connection->protocol_version);
 }
@@ -109,15 +115,13 @@ bool id_h(connection_t *c) {
 }
 
 bool send_metakey(connection_t *c) {
-       char *buffer;
-       int len;
        bool x;
 
-       len = RSA_size(c->rsa_key);
+       int len = RSA_size(c->rsa_key);
 
        /* Allocate buffers for the meta key */
 
-       buffer = alloca(2 * len + 1);
+       char buffer[2 * len + 1];
        
        c->outkey = xrealloc(c->outkey, len);
 
@@ -126,7 +130,12 @@ bool send_metakey(connection_t *c) {
 
        /* Copy random data to the buffer */
 
-       RAND_pseudo_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:
@@ -155,8 +164,8 @@ bool send_metakey(connection_t *c) {
         */
 
        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)",
-                          c->name, c->hostname);
+               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;
        }
 
@@ -219,13 +228,16 @@ bool metakey_h(connection_t *c) {
 
        /* Convert the challenge from hexadecimal back to binary */
 
-       hex2bin(buffer, buffer, len);
+       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)",
-                          c->name, c->hostname);
+               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;
        }
 
@@ -287,22 +299,23 @@ bool metakey_h(connection_t *c) {
 }
 
 bool send_challenge(connection_t *c) {
-       char *buffer;
-       int len;
-
        /* 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 */
 
-       buffer = alloca(2 * len + 1);
+       char buffer[2 * len + 1];
 
        c->hischallenge = xrealloc(c->hischallenge, len);
 
        /* Copy random data to the buffer */
 
-       RAND_pseudo_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 */
 
@@ -340,7 +353,10 @@ bool challenge_h(connection_t *c) {
 
        /* Convert the challenge from hexadecimal back to binary */
 
-       hex2bin(buffer, c->mychallenge, len);
+       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;
+       }
 
        c->allow_request = CHAL_REPLY;
 
@@ -394,7 +410,10 @@ bool chal_reply_h(connection_t *c) {
 
        /* Convert the hash to binary format */
 
-       hex2bin(hishash, hishash, c->outdigest->md_size);
+       if(!hex2bin(hishash, hishash, c->outdigest->md_size)) {
+               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 */
 
@@ -497,7 +516,7 @@ static void send_everything(connection_t *c) {
 
 bool ack_h(connection_t *c) {
        char hisport[MAX_STRING_SIZE];
-       char *hisaddress, *dummy;
+       char *hisaddress;
        int weight, mtu;
        uint32_t options;
        node_t *n;
@@ -539,7 +558,7 @@ bool ack_h(connection_t *c) {
        if(get_config_int(lookup_config(c->config_tree, "PMTU"), &mtu) && mtu < n->mtu)
                n->mtu = mtu;
 
-       if(get_config_int(lookup_config(myself->connection->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)) {
@@ -566,10 +585,9 @@ bool ack_h(connection_t *c) {
        c->edge = new_edge();
        c->edge->from = myself;
        c->edge->to = n;
-       sockaddr2str(&c->address, &hisaddress, &dummy);
+       sockaddr2str(&c->address, &hisaddress, NULL);
        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;
@@ -581,7 +599,7 @@ bool ack_h(connection_t *c) {
        if(tunnelserver)
                send_add_edge(c, c->edge);
        else
-               send_add_edge(broadcast, c->edge);
+               send_add_edge(everyone, c->edge);
 
        /* Run MST and SSSP algorithms */