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bitcoin-bitcoin-core/src/torcontrol.cpp
Ava Chow 7ff8e6b240
Merge bitcoin/bitcoin#28318: logging: Simplify API for level based logging
e60fc7d5d3 logging: Replace uses of LogPrintfCategory (Anthony Towns)
f7ce5ac08c logging: add LogError, LogWarning, LogInfo, LogDebug, LogTrace (Anthony Towns)
fbd7642c8e logging: add -loglevelalways=1 option (Anthony Towns)
782bb6a056 logging: treat BCLog::ALL like BCLog::NONE (Anthony Towns)
667ce3e329 logging: Drop BCLog::Level::None (Anthony Towns)
ab34dc6012 logging: Log Info messages unconditionally (Anthony Towns)
dfe98b6874 logging: make [cat:debug] and [info] implicit (Anthony Towns)
c5c76dc615 logging: refactor: pull prefix code out (Anthony Towns)

Pull request description:

  Replace `LogPrint*` functions with severity based logging functions:

   * `LogInfo(...)`, `LogWarning(...)`, `LogError(...)` for unconditional (uncategorised) logging (replaces `LogPrintf`)
   * `LogDebug(CATEGORY, ...)` and `LogTrace(CATEGORY, ...)` for conditional logging (replaces `LogPrint`)
   * `LogPrintLevel(CATEGORY, LEVEL, ...)` for when the level isn't known in advance, or a category needs to be added for an info/warning/error log message (mostly unchanged, but rarely needed)

  Logs look roughly as they do now with `LogInfo` not having an `[info]` prefix, and `LogDebug` having a `[cat]` prefix, rather than a `[cat:debug]` prefix. This removes `BCLog::Level::None` entirely -- for `LogFlags::NONE` just use `Level::Info`, for any actual category, use `Level::Debug`.

  Adds docs to developer-notes about when to use which level.

  Adds `-loglevelalways=1` option so that you get `[net:debug]`, `[all:info]`, `[all:warning]` etc, which might be helpful for automated parsing, or just if you like everything to be consistent. Defaults to off to reduce noise in the default config, and to avoid unnecessary changes on upgrades.

  Changes the behaviour of `LogPrintLevel(CATEGORY, BCLog::Level::Info, ...)` to be logged unconditionally, rather than only being an additional optional logging level in addition to trace and debug. Does not change the behaviour of `LogPrintLevel(NONE, Debug, ...)` and `LogPrintLevel(NONE, Trace, ...)` being no-ops.

ACKs for top commit:
  maflcko:
    re-ACK e60fc7d5d3 🌚
  achow101:
    ACK e60fc7d5d3
  stickies-v:
    ACK e60fc7d5d3
  jamesob:
    ACK e60fc7d5d3 ([`jamesob/ackr/28318.1.ajtowns.logging_simplify_api_for`](https://github.com/jamesob/bitcoin/tree/ackr/28318.1.ajtowns.logging_simplify_api_for))

Tree-SHA512: e7a4588779b148242495b7b6f64198a00c314cd57100affab11c43e9d39c9bbf85118ee2002792087fdcffdea08c84576e20844b3079f27083e26ddd7ca15d7f
2024-01-10 14:11:32 -05:00

715 lines
29 KiB
C++

// Copyright (c) 2015-2022 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 <common/args.h>
#include <compat/compat.h>
#include <crypto/hmac_sha256.h>
#include <logging.h>
#include <net.h>
#include <netaddress.h>
#include <netbase.h>
#include <random.h>
#include <tinyformat.h>
#include <util/check.h>
#include <util/fs.h>
#include <util/readwritefile.h>
#include <util/strencodings.h>
#include <util/string.h>
#include <util/thread.h>
#include <util/time.h>
#include <algorithm>
#include <cassert>
#include <cstdlib>
#include <deque>
#include <functional>
#include <map>
#include <optional>
#include <set>
#include <thread>
#include <utility>
#include <vector>
#include <event2/buffer.h>
#include <event2/bufferevent.h>
#include <event2/event.h>
#include <event2/thread.h>
#include <event2/util.h>
/** Default control ip and port */
const std::string DEFAULT_TOR_CONTROL = "127.0.0.1:" + ToString(DEFAULT_TOR_CONTROL_PORT);
/** 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;
static const uint16_t DEFAULT_TOR_SOCKS_PORT = 9050;
/****** Low-level TorControlConnection ********/
TorControlConnection::TorControlConnection(struct event_base* _base)
: base(_base)
{
}
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 = ToIntegral<int>(s.substr(0, 3)).value_or(0);
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) {
// (currently unused)
// Dispatch async notifications to async handler
// Synchronous and asynchronous messages are never interleaved
} 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, "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, "Successfully connected!\n");
self->connected(*self);
} else if (what & (BEV_EVENT_EOF|BEV_EVENT_ERROR)) {
if (what & BEV_EVENT_ERROR) {
LogPrint(BCLog::TOR, "Error connecting to Tor control socket\n");
} else {
LogPrint(BCLog::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();
}
const std::optional<CService> control_service{Lookup(tor_control_center, DEFAULT_TOR_CONTROL_PORT, fNameLookup)};
if (!control_service.has_value()) {
LogPrintf("tor: Failed to look up control center %s\n", tor_control_center);
return false;
}
struct sockaddr_storage control_address;
socklen_t control_address_len = sizeof(control_address);
if (!control_service.value().GetSockAddr(reinterpret_cast<struct sockaddr*>(&control_address), &control_address_len)) {
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, reinterpret_cast<struct sockaddr*>(&control_address), control_address_len) < 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 implementers 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--;
}
const auto end{i + j};
uint8_t val{0};
while (i < end) {
val *= 8;
val += value[i++] - '0';
}
escaped_value.push_back(char(val));
// Account for automatic incrementing at loop end
--i;
} 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;
}
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_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, "Reading cached private key from %s\n", fs::PathToString(GetPrivateKeyFile()));
private_key = pkf.second;
}
}
TorController::~TorController()
{
if (reconnect_ev) {
event_free(reconnect_ev);
reconnect_ev = nullptr;
}
if (service.IsValid()) {
RemoveLocal(service);
}
}
void TorController::get_socks_cb(TorControlConnection& _conn, const TorControlReply& reply)
{
// NOTE: We can only get here if -onion is unset
std::string socks_location;
if (reply.code == 250) {
for (const auto& line : reply.lines) {
if (0 == line.compare(0, 20, "net/listeners/socks=")) {
const std::string port_list_str = line.substr(20);
std::vector<std::string> port_list = SplitString(port_list_str, ' ');
for (auto& portstr : port_list) {
if (portstr.empty()) continue;
if ((portstr[0] == '"' || portstr[0] == '\'') && portstr.size() >= 2 && (*portstr.rbegin() == portstr[0])) {
portstr = portstr.substr(1, portstr.size() - 2);
if (portstr.empty()) continue;
}
socks_location = portstr;
if (0 == portstr.compare(0, 10, "127.0.0.1:")) {
// Prefer localhost - ignore other ports
break;
}
}
}
}
if (!socks_location.empty()) {
LogPrint(BCLog::TOR, "Get SOCKS port command yielded %s\n", socks_location);
} else {
LogPrintf("tor: Get SOCKS port command returned nothing\n");
}
} else if (reply.code == 510) { // 510 Unrecognized command
LogPrintf("tor: Get SOCKS port command failed with unrecognized command (You probably should upgrade Tor)\n");
} else {
LogPrintf("tor: Get SOCKS port command failed; error code %d\n", reply.code);
}
CService resolved;
Assume(!resolved.IsValid());
if (!socks_location.empty()) {
resolved = LookupNumeric(socks_location, DEFAULT_TOR_SOCKS_PORT);
}
if (!resolved.IsValid()) {
// Fallback to old behaviour
resolved = LookupNumeric("127.0.0.1", DEFAULT_TOR_SOCKS_PORT);
}
Assume(resolved.IsValid());
LogPrint(BCLog::TOR, "Configuring onion proxy for %s\n", resolved.ToStringAddrPort());
Proxy addrOnion = Proxy(resolved, true);
SetProxy(NET_ONION, addrOnion);
const auto onlynets = gArgs.GetArgs("-onlynet");
const bool onion_allowed_by_onlynet{
!gArgs.IsArgSet("-onlynet") ||
std::any_of(onlynets.begin(), onlynets.end(), [](const auto& n) {
return ParseNetwork(n) == NET_ONION;
})};
if (onion_allowed_by_onlynet) {
// If NET_ONION is reachable, then the below is a noop.
//
// If NET_ONION is not reachable, then none of -proxy or -onion was given.
// Since we are here, then -torcontrol and -torpassword were given.
g_reachable_nets.Add(NET_ONION);
}
}
void TorController::add_onion_cb(TorControlConnection& _conn, const TorControlReply& reply)
{
if (reply.code == 250) {
LogPrint(BCLog::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());
LogInfo("Got tor service ID %s, advertising service %s\n", service_id, service.ToStringAddrPort());
if (WriteBinaryFile(GetPrivateKeyFile(), private_key)) {
LogPrint(BCLog::TOR, "Cached service private key to %s\n", fs::PathToString(GetPrivateKeyFile()));
} else {
LogPrintf("tor: Error writing service private key to %s\n", fs::PathToString(GetPrivateKeyFile()));
}
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, "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", "") == "") {
_conn.Command("GETINFO net/listeners/socks", std::bind(&TorController::get_socks_cb, this, std::placeholders::_1, std::placeholders::_2));
}
// 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.ToStringAddrPort()),
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, "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, "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()) {
std::vector<std::string> m_vec = SplitString(i->second, ',');
methods = std::set<std::string>(m_vec.begin(), m_vec.end());
}
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, "Connected to Tor version %s\n", i->second);
}
}
}
for (const std::string &s : methods) {
LogPrint(BCLog::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, "Using HASHEDPASSWORD authentication\n");
ReplaceAll(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, "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, "Using SAFECOOKIE authentication, reading cookie authentication from %s\n", cookiefile);
std::pair<bool,std::string> status_cookie = ReadBinaryFile(fs::PathFromString(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);
_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, "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 gArgs.GetDataDirNet() / "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(&util::TraceThread, "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()};
}