torcontrol.cpp File Reference

#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 <chrono>
#include <cstdint>
#include <cstdlib>
#include <deque>
#include <functional>
#include <map>
#include <optional>
#include <set>
#include <thread>
#include <utility>
#include <vector>

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Functions
std::pair< std::string, std::string >	SplitTorReplyLine (const std::string &s)
std::map< std::string, std::string >	ParseTorReplyMapping (const std::string &s)
	Parse reply arguments in the form 'METHODS=COOKIE,SAFECOOKIE COOKIEFILE=".../control_auth_cookie"'. More...
static std::string	MakeAddOnionCmd (const std::string &private_key, const std::string &target, bool enable_pow)
static std::vector< uint8_t >	ComputeResponse (std::string_view key, std::span< const uint8_t > cookie, std::span< const uint8_t > client_nonce, std::span< const uint8_t > server_nonce)
	Compute Tor SAFECOOKIE response. More...
CService	DefaultOnionServiceTarget (uint16_t port)

Variables
const std::string	DEFAULT_TOR_CONTROL = "127.0.0.1:" + ToString(DEFAULT_TOR_CONTROL_PORT)
	Default control ip and port. More...
constexpr int	TOR_COOKIE_SIZE = 32
	Tor cookie size (from control-spec.txt) More...
constexpr int	TOR_NONCE_SIZE = 32
	Size of client/server nonce for SAFECOOKIE. More...
static const std::string	TOR_SAFE_SERVERKEY = "Tor safe cookie authentication server-to-controller hash"
	For computing server_hash in SAFECOOKIE. More...
static const std::string	TOR_SAFE_CLIENTKEY = "Tor safe cookie authentication controller-to-server hash"
	For computing clientHash in SAFECOOKIE. More...
constexpr std::chrono::duration< double >	RECONNECT_TIMEOUT_START {1.0}
	Exponential backoff configuration - initial timeout in seconds. More...
constexpr double	RECONNECT_TIMEOUT_EXP = 1.5
	Exponential backoff configuration - growth factor. More...
constexpr std::chrono::duration< double >	RECONNECT_TIMEOUT_MAX {600.0}
	Maximum reconnect timeout in seconds to prevent excessive delays. More...
constexpr int	MAX_LINE_LENGTH = 100000
	Maximum length for lines received on TorControlConnection. More...
constexpr auto	SOCKET_SEND_TIMEOUT = 10s
	Timeout for socket operations. More...

Function Documentation

ComputeResponse()

static std::vector< uint8_t > ComputeResponse ( std::string_view  key, std::span< const uint8_t >  cookie, std::span< const uint8_t >  client_nonce, std::span< const uint8_t >  server_nonce  )

static

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)

Definition at line 590 of file torcontrol.cpp.

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DefaultOnionServiceTarget()

CService DefaultOnionServiceTarget

(

uint16_t

port

)

Definition at line 742 of file torcontrol.cpp.

MakeAddOnionCmd()

static std::string MakeAddOnionCmd ( const std::string &  private_key, const std::string &  target, bool  enable_pow  )

static

Definition at line 498 of file torcontrol.cpp.

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ParseTorReplyMapping()

std::map< std::string, std::string > ParseTorReplyMapping

(

const std::string &

s

)

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.

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
\t \r and \0 ... \377 as C escapes. Treat a backslash followed by any other character as that character.

Definition at line 251 of file torcontrol.cpp.

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SplitTorReplyLine()

std::pair< std::string, std::string > SplitTorReplyLine

(

const std::string &

s

)

Definition at line 232 of file torcontrol.cpp.

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Variable Documentation

DEFAULT_TOR_CONTROL

const std::string DEFAULT_TOR_CONTROL = "127.0.0.1:" + ToString(DEFAULT_TOR_CONTROL_PORT)

Default control ip and port.

Definition at line 46 of file torcontrol.cpp.

MAX_LINE_LENGTH

constexpr int MAX_LINE_LENGTH = 100000

constexpr

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.

Definition at line 65 of file torcontrol.cpp.

RECONNECT_TIMEOUT_EXP

constexpr double RECONNECT_TIMEOUT_EXP = 1.5

constexpr

Exponential backoff configuration - growth factor.

Definition at line 58 of file torcontrol.cpp.

RECONNECT_TIMEOUT_MAX

constexpr std::chrono::duration<double> RECONNECT_TIMEOUT_MAX {600.0}

constexpr

Maximum reconnect timeout in seconds to prevent excessive delays.

Definition at line 60 of file torcontrol.cpp.

RECONNECT_TIMEOUT_START

constexpr std::chrono::duration<double> RECONNECT_TIMEOUT_START {1.0}

constexpr

Exponential backoff configuration - initial timeout in seconds.

Definition at line 56 of file torcontrol.cpp.

SOCKET_SEND_TIMEOUT

constexpr auto SOCKET_SEND_TIMEOUT = 10s

constexpr

Timeout for socket operations.

Definition at line 67 of file torcontrol.cpp.

TOR_COOKIE_SIZE

constexpr int TOR_COOKIE_SIZE = 32

constexpr

Tor cookie size (from control-spec.txt)

Definition at line 48 of file torcontrol.cpp.

TOR_NONCE_SIZE

constexpr int TOR_NONCE_SIZE = 32

constexpr

Size of client/server nonce for SAFECOOKIE.

Definition at line 50 of file torcontrol.cpp.

TOR_SAFE_CLIENTKEY

const std::string TOR_SAFE_CLIENTKEY = "Tor safe cookie authentication controller-to-server hash"

static

For computing clientHash in SAFECOOKIE.

Definition at line 54 of file torcontrol.cpp.

TOR_SAFE_SERVERKEY

const std::string TOR_SAFE_SERVERKEY = "Tor safe cookie authentication server-to-controller hash"

static

For computing server_hash in SAFECOOKIE.

Definition at line 52 of file torcontrol.cpp.