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litecoin/src/torcontrol.cpp

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// Copyright (c) 2015-2019 The Bitcoin Core developers
// Copyright (c) 2017 The Zcash developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
#include <torcontrol.h>
#include <chainparams.h>
#include <chainparamsbase.h>
#include <crypto/hmac_sha256.h>
#include <net.h>
#include <netaddress.h>
#include <netbase.h>
#include <util/strencodings.h>
#include <util/system.h>
#include <vector>
#include <deque>
#include <set>
#include <stdlib.h>
#include <boost/signals2/signal.hpp>
#include <boost/algorithm/string/split.hpp>
#include <boost/algorithm/string/classification.hpp>
#include <boost/algorithm/string/replace.hpp>
#include <event2/bufferevent.h>
#include <event2/buffer.h>
#include <event2/util.h>
#include <event2/event.h>
#include <event2/thread.h>
/** Default control port */
const std::string DEFAULT_TOR_CONTROL = "127.0.0.1:9051";
/** Tor cookie size (from control-spec.txt) */
static const int TOR_COOKIE_SIZE = 32;
/** Size of client/server nonce for SAFECOOKIE */
static const int TOR_NONCE_SIZE = 32;
/** For computing serverHash in SAFECOOKIE */
static const std::string TOR_SAFE_SERVERKEY = "Tor safe cookie authentication server-to-controller hash";
/** For computing clientHash in SAFECOOKIE */
static const std::string TOR_SAFE_CLIENTKEY = "Tor safe cookie authentication controller-to-server hash";
/** Exponential backoff configuration - initial timeout in seconds */
static const float RECONNECT_TIMEOUT_START = 1.0;
/** Exponential backoff configuration - growth factor */
static const float RECONNECT_TIMEOUT_EXP = 1.5;
/** Maximum length for lines received on TorControlConnection.
* tor-control-spec.txt mentions that there is explicitly no limit defined to line length,
* this is belt-and-suspenders sanity limit to prevent memory exhaustion.
*/
static const int MAX_LINE_LENGTH = 100000;
/****** Low-level TorControlConnection ********/
/** Reply from Tor, can be single or multi-line */
class TorControlReply
{
public:
TorControlReply() { Clear(); }
int code;
std::vector<std::string> lines;
void Clear()
{
code = 0;
lines.clear();
}
};
/** Low-level handling for Tor control connection.
* Speaks the SMTP-like protocol as defined in torspec/control-spec.txt
*/
class TorControlConnection
{
public:
typedef std::function<void(TorControlConnection&)> ConnectionCB;
typedef std::function<void(TorControlConnection &,const TorControlReply &)> ReplyHandlerCB;
/** Create a new TorControlConnection.
*/
explicit TorControlConnection(struct event_base *base);
~TorControlConnection();
/**
* Connect to a Tor control port.
* tor_control_center is address of the form host:port.
* connected is the handler that is called when connection is successfully established.
* disconnected is a handler that is called when the connection is broken.
* Return true on success.
*/
bool Connect(const std::string& tor_control_center, const ConnectionCB& connected, const ConnectionCB& disconnected);
/**
* Disconnect from Tor control port.
*/
void Disconnect();
/** Send a command, register a handler for the reply.
* A trailing CRLF is automatically added.
* Return true on success.
*/
bool Command(const std::string &cmd, const ReplyHandlerCB& reply_handler);
/** Response handlers for async replies */
boost::signals2::signal<void(TorControlConnection &,const TorControlReply &)> async_handler;
private:
/** Callback when ready for use */
std::function<void(TorControlConnection&)> connected;
/** Callback when connection lost */
std::function<void(TorControlConnection&)> disconnected;
/** Libevent event base */
struct event_base *base;
/** Connection to control socket */
struct bufferevent *b_conn;
/** Message being received */
TorControlReply message;
/** Response handlers */
std::deque<ReplyHandlerCB> reply_handlers;
/** Libevent handlers: internal */
static void readcb(struct bufferevent *bev, void *ctx);
static void eventcb(struct bufferevent *bev, short what, void *ctx);
};
TorControlConnection::TorControlConnection(struct event_base *_base):
base(_base), b_conn(nullptr)
{
}
TorControlConnection::~TorControlConnection()
{
if (b_conn)
bufferevent_free(b_conn);
}
void TorControlConnection::readcb(struct bufferevent *bev, void *ctx)
{
TorControlConnection *self = static_cast<TorControlConnection*>(ctx);
struct evbuffer *input = bufferevent_get_input(bev);
size_t n_read_out = 0;
char *line;
assert(input);
// If there is not a whole line to read, evbuffer_readln returns nullptr
while((line = evbuffer_readln(input, &n_read_out, EVBUFFER_EOL_CRLF)) != nullptr)
{
std::string s(line, n_read_out);
free(line);
if (s.size() < 4) // Short line
continue;
// <status>(-|+| )<data><CRLF>
self->message.code = atoi(s.substr(0,3));
self->message.lines.push_back(s.substr(4));
char ch = s[3]; // '-','+' or ' '
if (ch == ' ') {
// Final line, dispatch reply and clean up
if (self->message.code >= 600) {
// Dispatch async notifications to async handler
// Synchronous and asynchronous messages are never interleaved
self->async_handler(*self, self->message);
} else {
if (!self->reply_handlers.empty()) {
// Invoke reply handler with message
self->reply_handlers.front()(*self, self->message);
self->reply_handlers.pop_front();
} else {
LogPrint(BCLog::TOR, "tor: Received unexpected sync reply %i\n", self->message.code);
}
}
self->message.Clear();
}
}
// Check for size of buffer - protect against memory exhaustion with very long lines
// Do this after evbuffer_readln to make sure all full lines have been
// removed from the buffer. Everything left is an incomplete line.
if (evbuffer_get_length(input) > MAX_LINE_LENGTH) {
LogPrintf("tor: Disconnecting because MAX_LINE_LENGTH exceeded\n");
self->Disconnect();
}
}
void TorControlConnection::eventcb(struct bufferevent *bev, short what, void *ctx)
{
TorControlConnection *self = static_cast<TorControlConnection*>(ctx);
if (what & BEV_EVENT_CONNECTED) {
LogPrint(BCLog::TOR, "tor: Successfully connected!\n");
self->connected(*self);
} else if (what & (BEV_EVENT_EOF|BEV_EVENT_ERROR)) {
if (what & BEV_EVENT_ERROR) {
LogPrint(BCLog::TOR, "tor: Error connecting to Tor control socket\n");
} else {
LogPrint(BCLog::TOR, "tor: End of stream\n");
}
self->Disconnect();
self->disconnected(*self);
}
}
bool TorControlConnection::Connect(const std::string& tor_control_center, const ConnectionCB& _connected, const ConnectionCB& _disconnected)
{
if (b_conn)
Disconnect();
// Parse tor_control_center address:port
struct sockaddr_storage connect_to_addr;
int connect_to_addrlen = sizeof(connect_to_addr);
if (evutil_parse_sockaddr_port(tor_control_center.c_str(),
(struct sockaddr*)&connect_to_addr, &connect_to_addrlen)<0) {
LogPrintf("tor: Error parsing socket address %s\n", tor_control_center);
return false;
}
// Create a new socket, set up callbacks and enable notification bits
b_conn = bufferevent_socket_new(base, -1, BEV_OPT_CLOSE_ON_FREE);
if (!b_conn)
return false;
bufferevent_setcb(b_conn, TorControlConnection::readcb, nullptr, TorControlConnection::eventcb, this);
bufferevent_enable(b_conn, EV_READ|EV_WRITE);
this->connected = _connected;
this->disconnected = _disconnected;
// Finally, connect to tor_control_center
if (bufferevent_socket_connect(b_conn, (struct sockaddr*)&connect_to_addr, connect_to_addrlen) < 0) {
LogPrintf("tor: Error connecting to address %s\n", tor_control_center);
return false;
}
return true;
}
void TorControlConnection::Disconnect()
{
if (b_conn)
bufferevent_free(b_conn);
b_conn = nullptr;
}
bool TorControlConnection::Command(const std::string &cmd, const ReplyHandlerCB& reply_handler)
{
if (!b_conn)
return false;
struct evbuffer *buf = bufferevent_get_output(b_conn);
if (!buf)
return false;
evbuffer_add(buf, cmd.data(), cmd.size());
evbuffer_add(buf, "\r\n", 2);
reply_handlers.push_back(reply_handler);
return true;
}
/****** General parsing utilities ********/
/* Split reply line in the form 'AUTH METHODS=...' into a type
* 'AUTH' and arguments 'METHODS=...'.
* Grammar is implicitly defined in https://spec.torproject.org/control-spec by
* the server reply formats for PROTOCOLINFO (S3.21) and AUTHCHALLENGE (S3.24).
*/
std::pair<std::string,std::string> SplitTorReplyLine(const std::string &s)
{
size_t ptr=0;
std::string type;
while (ptr < s.size() && s[ptr] != ' ') {
type.push_back(s[ptr]);
++ptr;
}
if (ptr < s.size())
++ptr; // skip ' '
return make_pair(type, s.substr(ptr));
}
/** Parse reply arguments in the form 'METHODS=COOKIE,SAFECOOKIE COOKIEFILE=".../control_auth_cookie"'.
* Returns a map of keys to values, or an empty map if there was an error.
* Grammar is implicitly defined in https://spec.torproject.org/control-spec by
* the server reply formats for PROTOCOLINFO (S3.21), AUTHCHALLENGE (S3.24),
* and ADD_ONION (S3.27). See also sections 2.1 and 2.3.
*/
std::map<std::string,std::string> ParseTorReplyMapping(const std::string &s)
{
std::map<std::string,std::string> mapping;
size_t ptr=0;
while (ptr < s.size()) {
std::string key, value;
while (ptr < s.size() && s[ptr] != '=' && s[ptr] != ' ') {
key.push_back(s[ptr]);
++ptr;
}
if (ptr == s.size()) // unexpected end of line
return std::map<std::string,std::string>();
if (s[ptr] == ' ') // The remaining string is an OptArguments
break;
++ptr; // skip '='
if (ptr < s.size() && s[ptr] == '"') { // Quoted string
++ptr; // skip opening '"'
bool escape_next = false;
while (ptr < s.size() && (escape_next || s[ptr] != '"')) {
// Repeated backslashes must be interpreted as pairs
escape_next = (s[ptr] == '\\' && !escape_next);
value.push_back(s[ptr]);
++ptr;
}
if (ptr == s.size()) // unexpected end of line
return std::map<std::string,std::string>();
++ptr; // skip closing '"'
/**
* Unescape value. Per https://spec.torproject.org/control-spec section 2.1.1:
*
* For future-proofing, controller implementors MAY use the following
* rules to be compatible with buggy Tor implementations and with
* future ones that implement the spec as intended:
*
* Read \n \t \r and \0 ... \377 as C escapes.
* Treat a backslash followed by any other character as that character.
*/
std::string escaped_value;
for (size_t i = 0; i < value.size(); ++i) {
if (value[i] == '\\') {
// This will always be valid, because if the QuotedString
// ended in an odd number of backslashes, then the parser
// would already have returned above, due to a missing
// terminating double-quote.
++i;
if (value[i] == 'n') {
escaped_value.push_back('\n');
} else if (value[i] == 't') {
escaped_value.push_back('\t');
} else if (value[i] == 'r') {
escaped_value.push_back('\r');
} else if ('0' <= value[i] && value[i] <= '7') {
size_t j;
// Octal escape sequences have a limit of three octal digits,
// but terminate at the first character that is not a valid
// octal digit if encountered sooner.
for (j = 1; j < 3 && (i+j) < value.size() && '0' <= value[i+j] && value[i+j] <= '7'; ++j) {}
// Tor restricts first digit to 0-3 for three-digit octals.
// A leading digit of 4-7 would therefore be interpreted as
// a two-digit octal.
if (j == 3 && value[i] > '3') {
j--;
}
escaped_value.push_back(strtol(value.substr(i, j).c_str(), nullptr, 8));
// Account for automatic incrementing at loop end
i += j - 1;
} else {
escaped_value.push_back(value[i]);
}
} else {
escaped_value.push_back(value[i]);
}
}
value = escaped_value;
} else { // Unquoted value. Note that values can contain '=' at will, just no spaces
while (ptr < s.size() && s[ptr] != ' ') {
value.push_back(s[ptr]);
++ptr;
}
}
if (ptr < s.size() && s[ptr] == ' ')
++ptr; // skip ' ' after key=value
mapping[key] = value;
}
return mapping;
}
/** Read full contents of a file and return them in a std::string.
* Returns a pair <status, string>.
* If an error occurred, status will be false, otherwise status will be true and the data will be returned in string.
*
* @param maxsize Puts a maximum size limit on the file that is read. If the file is larger than this, truncated data
* (with len > maxsize) will be returned.
*/
static std::pair<bool,std::string> ReadBinaryFile(const fs::path &filename, size_t maxsize=std::numeric_limits<size_t>::max())
{
FILE *f = fsbridge::fopen(filename, "rb");
if (f == nullptr)
return std::make_pair(false,"");
std::string retval;
char buffer[128];
size_t n;
while ((n=fread(buffer, 1, sizeof(buffer), f)) > 0) {
// Check for reading errors so we don't return any data if we couldn't
// read the entire file (or up to maxsize)
if (ferror(f)) {
fclose(f);
return std::make_pair(false,"");
}
retval.append(buffer, buffer+n);
if (retval.size() > maxsize)
break;
}
fclose(f);
return std::make_pair(true,retval);
}
/** Write contents of std::string to a file.
* @return true on success.
*/
static bool WriteBinaryFile(const fs::path &filename, const std::string &data)
{
FILE *f = fsbridge::fopen(filename, "wb");
if (f == nullptr)
return false;
if (fwrite(data.data(), 1, data.size(), f) != data.size()) {
fclose(f);
return false;
}
fclose(f);
return true;
}
/****** Bitcoin specific TorController implementation ********/
/** Controller that connects to Tor control socket, authenticate, then create
* and maintain an ephemeral onion service.
*/
class TorController
{
public:
TorController(struct event_base* base, const std::string& tor_control_center, const CService& target);
~TorController();
/** Get name of file to store private key in */
fs::path GetPrivateKeyFile();
/** Reconnect, after getting disconnected */
void Reconnect();
private:
struct event_base* base;
const std::string m_tor_control_center;
TorControlConnection conn;
std::string private_key;
std::string service_id;
bool reconnect;
struct event *reconnect_ev;
float reconnect_timeout;
CService service;
const CService m_target;
/** Cookie for SAFECOOKIE auth */
std::vector<uint8_t> cookie;
/** ClientNonce for SAFECOOKIE auth */
std::vector<uint8_t> clientNonce;
/** Callback for ADD_ONION result */
void add_onion_cb(TorControlConnection& conn, const TorControlReply& reply);
/** Callback for AUTHENTICATE result */
void auth_cb(TorControlConnection& conn, const TorControlReply& reply);
/** Callback for AUTHCHALLENGE result */
void authchallenge_cb(TorControlConnection& conn, const TorControlReply& reply);
/** Callback for PROTOCOLINFO result */
void protocolinfo_cb(TorControlConnection& conn, const TorControlReply& reply);
/** Callback after successful connection */
void connected_cb(TorControlConnection& conn);
/** Callback after connection lost or failed connection attempt */
void disconnected_cb(TorControlConnection& conn);
/** Callback for reconnect timer */
static void reconnect_cb(evutil_socket_t fd, short what, void *arg);
};
TorController::TorController(struct event_base* _base, const std::string& tor_control_center, const CService& target):
base(_base),
m_tor_control_center(tor_control_center), conn(base), reconnect(true), reconnect_ev(0),
reconnect_timeout(RECONNECT_TIMEOUT_START),
m_target(target)
{
reconnect_ev = event_new(base, -1, 0, reconnect_cb, this);
if (!reconnect_ev)
LogPrintf("tor: Failed to create event for reconnection: out of memory?\n");
// Start connection attempts immediately
if (!conn.Connect(m_tor_control_center, std::bind(&TorController::connected_cb, this, std::placeholders::_1),
std::bind(&TorController::disconnected_cb, this, std::placeholders::_1) )) {
LogPrintf("tor: Initiating connection to Tor control port %s failed\n", m_tor_control_center);
}
// Read service private key if cached
std::pair<bool,std::string> pkf = ReadBinaryFile(GetPrivateKeyFile());
if (pkf.first) {
LogPrint(BCLog::TOR, "tor: Reading cached private key from %s\n", GetPrivateKeyFile().string());
private_key = pkf.second;
}
}
TorController::~TorController()
{
if (reconnect_ev) {
event_free(reconnect_ev);
reconnect_ev = nullptr;
}
if (service.IsValid()) {
RemoveLocal(service);
}
}
void TorController::add_onion_cb(TorControlConnection& _conn, const TorControlReply& reply)
{
if (reply.code == 250) {
LogPrint(BCLog::TOR, "tor: ADD_ONION successful\n");
for (const std::string &s : reply.lines) {
std::map<std::string,std::string> m = ParseTorReplyMapping(s);
std::map<std::string,std::string>::iterator i;
if ((i = m.find("ServiceID")) != m.end())
service_id = i->second;
if ((i = m.find("PrivateKey")) != m.end())
private_key = i->second;
}
if (service_id.empty()) {
LogPrintf("tor: Error parsing ADD_ONION parameters:\n");
for (const std::string &s : reply.lines) {
LogPrintf(" %s\n", SanitizeString(s));
}
return;
}
service = LookupNumeric(std::string(service_id+".onion"), Params().GetDefaultPort());
LogPrintf("tor: Got service ID %s, advertising service %s\n", service_id, service.ToString());
if (WriteBinaryFile(GetPrivateKeyFile(), private_key)) {
LogPrint(BCLog::TOR, "tor: Cached service private key to %s\n", GetPrivateKeyFile().string());
} else {
LogPrintf("tor: Error writing service private key to %s\n", GetPrivateKeyFile().string());
}
AddLocal(service, LOCAL_MANUAL);
// ... onion requested - keep connection open
} else if (reply.code == 510) { // 510 Unrecognized command
LogPrintf("tor: Add onion failed with unrecognized command (You probably need to upgrade Tor)\n");
} else {
LogPrintf("tor: Add onion failed; error code %d\n", reply.code);
}
}
void TorController::auth_cb(TorControlConnection& _conn, const TorControlReply& reply)
{
if (reply.code == 250) {
LogPrint(BCLog::TOR, "tor: Authentication successful\n");
// Now that we know Tor is running setup the proxy for onion addresses
// if -onion isn't set to something else.
if (gArgs.GetArg("-onion", "") == "") {
CService resolved(LookupNumeric("127.0.0.1", 9050));
proxyType addrOnion = proxyType(resolved, true);
SetProxy(NET_ONION, addrOnion);
SetReachable(NET_ONION, true);
}
// Finally - now create the service
if (private_key.empty()) { // No private key, generate one
private_key = "NEW:ED25519-V3"; // Explicitly request key type - see issue #9214
}
// Request onion service, redirect port.
// Note that the 'virtual' port is always the default port to avoid decloaking nodes using other ports.
_conn.Command(strprintf("ADD_ONION %s Port=%i,%s", private_key, Params().GetDefaultPort(), m_target.ToStringIPPort()),
std::bind(&TorController::add_onion_cb, this, std::placeholders::_1, std::placeholders::_2));
} else {
LogPrintf("tor: Authentication failed\n");
}
}
/** Compute Tor SAFECOOKIE response.
*
* ServerHash is computed as:
* HMAC-SHA256("Tor safe cookie authentication server-to-controller hash",
* CookieString | ClientNonce | ServerNonce)
* (with the HMAC key as its first argument)
*
* After a controller sends a successful AUTHCHALLENGE command, the
* next command sent on the connection must be an AUTHENTICATE command,
* and the only authentication string which that AUTHENTICATE command
* will accept is:
*
* HMAC-SHA256("Tor safe cookie authentication controller-to-server hash",
* CookieString | ClientNonce | ServerNonce)
*
*/
static std::vector<uint8_t> ComputeResponse(const std::string &key, const std::vector<uint8_t> &cookie, const std::vector<uint8_t> &clientNonce, const std::vector<uint8_t> &serverNonce)
{
CHMAC_SHA256 computeHash((const uint8_t*)key.data(), key.size());
std::vector<uint8_t> computedHash(CHMAC_SHA256::OUTPUT_SIZE, 0);
computeHash.Write(cookie.data(), cookie.size());
computeHash.Write(clientNonce.data(), clientNonce.size());
computeHash.Write(serverNonce.data(), serverNonce.size());
computeHash.Finalize(computedHash.data());
return computedHash;
}
void TorController::authchallenge_cb(TorControlConnection& _conn, const TorControlReply& reply)
{
if (reply.code == 250) {
LogPrint(BCLog::TOR, "tor: SAFECOOKIE authentication challenge successful\n");
std::pair<std::string,std::string> l = SplitTorReplyLine(reply.lines[0]);
if (l.first == "AUTHCHALLENGE") {
std::map<std::string,std::string> m = ParseTorReplyMapping(l.second);
if (m.empty()) {
LogPrintf("tor: Error parsing AUTHCHALLENGE parameters: %s\n", SanitizeString(l.second));
return;
}
std::vector<uint8_t> serverHash = ParseHex(m["SERVERHASH"]);
std::vector<uint8_t> serverNonce = ParseHex(m["SERVERNONCE"]);
LogPrint(BCLog::TOR, "tor: AUTHCHALLENGE ServerHash %s ServerNonce %s\n", HexStr(serverHash), HexStr(serverNonce));
if (serverNonce.size() != 32) {
LogPrintf("tor: ServerNonce is not 32 bytes, as required by spec\n");
return;
}
std::vector<uint8_t> computedServerHash = ComputeResponse(TOR_SAFE_SERVERKEY, cookie, clientNonce, serverNonce);
if (computedServerHash != serverHash) {
LogPrintf("tor: ServerHash %s does not match expected ServerHash %s\n", HexStr(serverHash), HexStr(computedServerHash));
return;
}
std::vector<uint8_t> computedClientHash = ComputeResponse(TOR_SAFE_CLIENTKEY, cookie, clientNonce, serverNonce);
_conn.Command("AUTHENTICATE " + HexStr(computedClientHash), std::bind(&TorController::auth_cb, this, std::placeholders::_1, std::placeholders::_2));
} else {
LogPrintf("tor: Invalid reply to AUTHCHALLENGE\n");
}
} else {
LogPrintf("tor: SAFECOOKIE authentication challenge failed\n");
}
}
void TorController::protocolinfo_cb(TorControlConnection& _conn, const TorControlReply& reply)
{
if (reply.code == 250) {
std::set<std::string> methods;
std::string cookiefile;
/*
* 250-AUTH METHODS=COOKIE,SAFECOOKIE COOKIEFILE="/home/x/.tor/control_auth_cookie"
* 250-AUTH METHODS=NULL
* 250-AUTH METHODS=HASHEDPASSWORD
*/
for (const std::string &s : reply.lines) {
std::pair<std::string,std::string> l = SplitTorReplyLine(s);
if (l.first == "AUTH") {
std::map<std::string,std::string> m = ParseTorReplyMapping(l.second);
std::map<std::string,std::string>::iterator i;
if ((i = m.find("METHODS")) != m.end())
boost::split(methods, i->second, boost::is_any_of(","));
if ((i = m.find("COOKIEFILE")) != m.end())
cookiefile = i->second;
} else if (l.first == "VERSION") {
std::map<std::string,std::string> m = ParseTorReplyMapping(l.second);
std::map<std::string,std::string>::iterator i;
if ((i = m.find("Tor")) != m.end()) {
LogPrint(BCLog::TOR, "tor: Connected to Tor version %s\n", i->second);
}
}
}
for (const std::string &s : methods) {
LogPrint(BCLog::TOR, "tor: Supported authentication method: %s\n", s);
}
// Prefer NULL, otherwise SAFECOOKIE. If a password is provided, use HASHEDPASSWORD
/* Authentication:
* cookie: hex-encoded ~/.tor/control_auth_cookie
* password: "password"
*/
std::string torpassword = gArgs.GetArg("-torpassword", "");
if (!torpassword.empty()) {
if (methods.count("HASHEDPASSWORD")) {
LogPrint(BCLog::TOR, "tor: Using HASHEDPASSWORD authentication\n");
boost::replace_all(torpassword, "\"", "\\\"");
_conn.Command("AUTHENTICATE \"" + torpassword + "\"", std::bind(&TorController::auth_cb, this, std::placeholders::_1, std::placeholders::_2));
} else {
LogPrintf("tor: Password provided with -torpassword, but HASHEDPASSWORD authentication is not available\n");
}
} else if (methods.count("NULL")) {
LogPrint(BCLog::TOR, "tor: Using NULL authentication\n");
_conn.Command("AUTHENTICATE", std::bind(&TorController::auth_cb, this, std::placeholders::_1, std::placeholders::_2));
} else if (methods.count("SAFECOOKIE")) {
// Cookie: hexdump -e '32/1 "%02x""\n"' ~/.tor/control_auth_cookie
LogPrint(BCLog::TOR, "tor: Using SAFECOOKIE authentication, reading cookie authentication from %s\n", cookiefile);
std::pair<bool,std::string> status_cookie = ReadBinaryFile(cookiefile, TOR_COOKIE_SIZE);
if (status_cookie.first && status_cookie.second.size() == TOR_COOKIE_SIZE) {
// _conn.Command("AUTHENTICATE " + HexStr(status_cookie.second), std::bind(&TorController::auth_cb, this, std::placeholders::_1, std::placeholders::_2));
cookie = std::vector<uint8_t>(status_cookie.second.begin(), status_cookie.second.end());
clientNonce = std::vector<uint8_t>(TOR_NONCE_SIZE, 0);
GetRandBytes(clientNonce.data(), TOR_NONCE_SIZE);
_conn.Command("AUTHCHALLENGE SAFECOOKIE " + HexStr(clientNonce), std::bind(&TorController::authchallenge_cb, this, std::placeholders::_1, std::placeholders::_2));
} else {
if (status_cookie.first) {
LogPrintf("tor: Authentication cookie %s is not exactly %i bytes, as is required by the spec\n", cookiefile, TOR_COOKIE_SIZE);
} else {
LogPrintf("tor: Authentication cookie %s could not be opened (check permissions)\n", cookiefile);
}
}
} else if (methods.count("HASHEDPASSWORD")) {
LogPrintf("tor: The only supported authentication mechanism left is password, but no password provided with -torpassword\n");
} else {
LogPrintf("tor: No supported authentication method\n");
}
} else {
LogPrintf("tor: Requesting protocol info failed\n");
}
}
void TorController::connected_cb(TorControlConnection& _conn)
{
reconnect_timeout = RECONNECT_TIMEOUT_START;
// First send a PROTOCOLINFO command to figure out what authentication is expected
if (!_conn.Command("PROTOCOLINFO 1", std::bind(&TorController::protocolinfo_cb, this, std::placeholders::_1, std::placeholders::_2)))
LogPrintf("tor: Error sending initial protocolinfo command\n");
}
void TorController::disconnected_cb(TorControlConnection& _conn)
{
// Stop advertising service when disconnected
if (service.IsValid())
RemoveLocal(service);
service = CService();
if (!reconnect)
return;
LogPrint(BCLog::TOR, "tor: Not connected to Tor control port %s, trying to reconnect\n", m_tor_control_center);
// Single-shot timer for reconnect. Use exponential backoff.
struct timeval time = MillisToTimeval(int64_t(reconnect_timeout * 1000.0));
if (reconnect_ev)
event_add(reconnect_ev, &time);
reconnect_timeout *= RECONNECT_TIMEOUT_EXP;
}
void TorController::Reconnect()
{
/* Try to reconnect and reestablish if we get booted - for example, Tor
* may be restarting.
*/
if (!conn.Connect(m_tor_control_center, std::bind(&TorController::connected_cb, this, std::placeholders::_1),
std::bind(&TorController::disconnected_cb, this, std::placeholders::_1) )) {
LogPrintf("tor: Re-initiating connection to Tor control port %s failed\n", m_tor_control_center);
}
}
fs::path TorController::GetPrivateKeyFile()
{
return GetDataDir() / "onion_v3_private_key";
}
void TorController::reconnect_cb(evutil_socket_t fd, short what, void *arg)
{
TorController *self = static_cast<TorController*>(arg);
self->Reconnect();
}
/****** Thread ********/
static struct event_base *gBase;
static std::thread torControlThread;
static void TorControlThread(CService onion_service_target)
{
TorController ctrl(gBase, gArgs.GetArg("-torcontrol", DEFAULT_TOR_CONTROL), onion_service_target);
event_base_dispatch(gBase);
}
void StartTorControl(CService onion_service_target)
{
assert(!gBase);
#ifdef WIN32
evthread_use_windows_threads();
#else
evthread_use_pthreads();
#endif
gBase = event_base_new();
if (!gBase) {
LogPrintf("tor: Unable to create event_base\n");
return;
}
torControlThread = std::thread(&TraceThread<std::function<void()>>, "torcontrol", [onion_service_target] {
TorControlThread(onion_service_target);
});
}
void InterruptTorControl()
{
if (gBase) {
LogPrintf("tor: Thread interrupt\n");
event_base_once(gBase, -1, EV_TIMEOUT, [](evutil_socket_t, short, void*) {
event_base_loopbreak(gBase);
}, nullptr, nullptr);
}
}
void StopTorControl()
{
if (gBase) {
torControlThread.join();
event_base_free(gBase);
gBase = nullptr;
}
}
CService DefaultOnionServiceTarget()
{
struct in_addr onion_service_target;
onion_service_target.s_addr = htonl(INADDR_LOOPBACK);
return {onion_service_target, BaseParams().OnionServiceTargetPort()};
}
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