diff options
| -rw-r--r-- | doc/files.md | 2 | ||||
| -rw-r--r-- | doc/release-notes.md | 17 | ||||
| -rw-r--r-- | doc/tor.md | 17 | ||||
| -rw-r--r-- | src/Makefile.am | 2 | ||||
| -rw-r--r-- | src/init.cpp | 11 | ||||
| -rw-r--r-- | src/main.cpp | 2 | ||||
| -rw-r--r-- | src/net.cpp | 9 | ||||
| -rw-r--r-- | src/net.h | 1 | ||||
| -rw-r--r-- | src/netbase.cpp | 5 | ||||
| -rw-r--r-- | src/netbase.h | 4 | ||||
| -rw-r--r-- | src/torcontrol.cpp | 685 | ||||
| -rw-r--r-- | src/torcontrol.h | 20 |
12 files changed, 771 insertions, 4 deletions
diff --git a/doc/files.md b/doc/files.md index c083bcb038..f7eca57dcb 100644 --- a/doc/files.md +++ b/doc/files.md @@ -12,6 +12,8 @@ * fee_estimates.dat: stores statistics used to estimate minimum transaction fees and priorities required for confirmation; since 0.10.0 * peers.dat: peer IP address database (custom format); since 0.7.0 * wallet.dat: personal wallet (BDB) with keys and transactions +* .cookie: session RPC authentication cookie (written at start when cookie authentication is used, deleted on shutdown): since 0.12.0 +* onion_private_key: cached Tor hidden service private key for `-listenonion`: since 0.12.0 Only used in pre-0.8.0 --------------------- diff --git a/doc/release-notes.md b/doc/release-notes.md index f5842127a1..31704ba47c 100644 --- a/doc/release-notes.md +++ b/doc/release-notes.md @@ -151,6 +151,23 @@ mining with the getblocktemplate protocol to a pool: this will affect you at the pool operator's discretion, which must be no later than BIP65 achieving its 951/1001 status. +Automatically listen on Tor +---------------------------- + +Starting with Tor version 0.2.7.1 it is possible, through Tor's control socket +API, to create and destroy 'ephemeral' hidden services programmatically. +Bitcoin Core has been updated to make use of this. + +This means that if Tor is running (and proper authorization is available), +Bitcoin Core automatically creates a hidden service to listen on, without +manual configuration. This will positively affect the number of available +.onion nodes. + +This new feature is enabled by default if Bitcoin Core is listening, and +a connection to Tor can be made. It can be configured with the `-listenonion`, +`-torcontrol` and `-torpassword` settings. To show verbose debugging +information, pass `-debug=tor`. + 0.12.0 Change log ================= diff --git a/doc/tor.md b/doc/tor.md index 594897f896..1d35a658bc 100644 --- a/doc/tor.md +++ b/doc/tor.md @@ -87,3 +87,20 @@ If you only want to use Tor to reach onion addresses, but not use it as a proxy for normal IPv4/IPv6 communication, use: ./bitcoin -onion=127.0.0.1:9050 -externalip=57qr3yd1nyntf5k.onion -discover + +3. Automatically listen on Tor +-------------------------------- + +Starting with Tor version 0.2.7.1 it is possible, through Tor's control socket +API, to create and destroy 'ephemeral' hidden services programmatically. +Bitcoin Core has been updated to make use of this. + +This means that if Tor is running (and proper authorization is available), +Bitcoin Core automatically creates a hidden service to listen on, without +manual configuration. This will positively affect the number of available +.onion nodes. + +This new feature is enabled by default if Bitcoin Core is listening, and +a connection to Tor can be made. It can be configured with the `-listenonion`, +`-torcontrol` and `-torpassword` settings. To show verbose debugging +information, pass `-debug=tor`. diff --git a/src/Makefile.am b/src/Makefile.am index c8d674686c..834c3dc891 100644 --- a/src/Makefile.am +++ b/src/Makefile.am @@ -151,6 +151,7 @@ BITCOIN_CORE_H = \ threadsafety.h \ timedata.h \ tinyformat.h \ + torcontrol.h \ txdb.h \ txmempool.h \ ui_interface.h \ @@ -209,6 +210,7 @@ libbitcoin_server_a_SOURCES = \ rpcserver.cpp \ script/sigcache.cpp \ timedata.cpp \ + torcontrol.cpp \ txdb.cpp \ txmempool.cpp \ validationinterface.cpp \ diff --git a/src/init.cpp b/src/init.cpp index 921fc0b64a..87a23deab7 100644 --- a/src/init.cpp +++ b/src/init.cpp @@ -29,6 +29,7 @@ #include "scheduler.h" #include "txdb.h" #include "txmempool.h" +#include "torcontrol.h" #include "ui_interface.h" #include "util.h" #include "utilmoneystr.h" @@ -160,6 +161,7 @@ void Interrupt(boost::thread_group& threadGroup) InterruptHTTPRPC(); InterruptRPC(); InterruptREST(); + InterruptTorControl(); threadGroup.interrupt_all(); } @@ -188,6 +190,7 @@ void Shutdown() #endif GenerateBitcoins(false, 0, Params()); StopNode(); + StopTorControl(); UnregisterNodeSignals(GetNodeSignals()); if (fFeeEstimatesInitialized) @@ -348,6 +351,7 @@ std::string HelpMessage(HelpMessageMode mode) strUsage += HelpMessageOpt("-externalip=<ip>", _("Specify your own public address")); strUsage += HelpMessageOpt("-forcednsseed", strprintf(_("Always query for peer addresses via DNS lookup (default: %u)"), 0)); strUsage += HelpMessageOpt("-listen", _("Accept connections from outside (default: 1 if no -proxy or -connect)")); + strUsage += HelpMessageOpt("-listenonion", strprintf(_("Automatically create Tor hidden service (default: %d)"), DEFAULT_LISTEN_ONION)); strUsage += HelpMessageOpt("-maxconnections=<n>", strprintf(_("Maintain at most <n> connections to peers (default: %u)"), DEFAULT_MAX_PEER_CONNECTIONS)); strUsage += HelpMessageOpt("-maxreceivebuffer=<n>", strprintf(_("Maximum per-connection receive buffer, <n>*1000 bytes (default: %u)"), 5000)); strUsage += HelpMessageOpt("-maxsendbuffer=<n>", strprintf(_("Maximum per-connection send buffer, <n>*1000 bytes (default: %u)"), 1000)); @@ -359,6 +363,8 @@ std::string HelpMessage(HelpMessageMode mode) strUsage += HelpMessageOpt("-proxyrandomize", strprintf(_("Randomize credentials for every proxy connection. This enables Tor stream isolation (default: %u)"), 1)); strUsage += HelpMessageOpt("-seednode=<ip>", _("Connect to a node to retrieve peer addresses, and disconnect")); strUsage += HelpMessageOpt("-timeout=<n>", strprintf(_("Specify connection timeout in milliseconds (minimum: 1, default: %d)"), DEFAULT_CONNECT_TIMEOUT)); + strUsage += HelpMessageOpt("-torcontrol=<ip>:<port>", strprintf(_("Tor control port to use if onion listening enabled (default: %s)"), DEFAULT_TOR_CONTROL)); + strUsage += HelpMessageOpt("-torpassword=<pass>", _("Tor control port password (default: empty)")); #ifdef USE_UPNP #if USE_UPNP strUsage += HelpMessageOpt("-upnp", _("Use UPnP to map the listening port (default: 1 when listening and no -proxy)")); @@ -778,6 +784,8 @@ bool AppInit2(boost::thread_group& threadGroup, CScheduler& scheduler) LogPrintf("%s: parameter interaction: -listen=0 -> setting -upnp=0\n", __func__); if (SoftSetBoolArg("-discover", false)) LogPrintf("%s: parameter interaction: -listen=0 -> setting -discover=0\n", __func__); + if (SoftSetBoolArg("-listenonion", false)) + LogPrintf("%s: parameter interaction: -listen=0 -> setting -listenonion=0\n", __func__); } if (mapArgs.count("-externalip")) { @@ -1568,6 +1576,9 @@ bool AppInit2(boost::thread_group& threadGroup, CScheduler& scheduler) LogPrintf("mapAddressBook.size() = %u\n", pwalletMain ? pwalletMain->mapAddressBook.size() : 0); #endif + if (GetBoolArg("-listenonion", DEFAULT_LISTEN_ONION)) + StartTorControl(threadGroup, scheduler); + StartNode(threadGroup, scheduler); // Monitor the chain, and alert if we get blocks much quicker or slower than expected diff --git a/src/main.cpp b/src/main.cpp index 3703701917..5208fbb031 100644 --- a/src/main.cpp +++ b/src/main.cpp @@ -4059,9 +4059,11 @@ bool static ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv, CAddress addr = GetLocalAddress(&pfrom->addr); if (addr.IsRoutable()) { + LogPrintf("ProcessMessages: advertizing address %s\n", addr.ToString()); pfrom->PushAddress(addr); } else if (IsPeerAddrLocalGood(pfrom)) { addr.SetIP(pfrom->addrLocal); + LogPrintf("ProcessMessages: advertizing address %s\n", addr.ToString()); pfrom->PushAddress(addr); } } diff --git a/src/net.cpp b/src/net.cpp index e18e8d0e29..ada4a1bb62 100644 --- a/src/net.cpp +++ b/src/net.cpp @@ -216,6 +216,7 @@ void AdvertizeLocal(CNode *pnode) } if (addrLocal.IsRoutable()) { + LogPrintf("AdvertizeLocal: advertizing address %s\n", addrLocal.ToString()); pnode->PushAddress(addrLocal); } } @@ -262,6 +263,14 @@ bool AddLocal(const CNetAddr &addr, int nScore) return AddLocal(CService(addr, GetListenPort()), nScore); } +bool RemoveLocal(const CService& addr) +{ + LOCK(cs_mapLocalHost); + LogPrintf("RemoveLocal(%s)\n", addr.ToString()); + mapLocalHost.erase(addr); + return true; +} + /** Make a particular network entirely off-limits (no automatic connects to it) */ void SetLimited(enum Network net, bool fLimited) { @@ -128,6 +128,7 @@ bool IsLimited(enum Network net); bool IsLimited(const CNetAddr& addr); bool AddLocal(const CService& addr, int nScore = LOCAL_NONE); bool AddLocal(const CNetAddr& addr, int nScore = LOCAL_NONE); +bool RemoveLocal(const CService& addr); bool SeenLocal(const CService& addr); bool IsLocal(const CService& addr); bool GetLocal(CService &addr, const CNetAddr *paddrPeer = NULL); diff --git a/src/netbase.cpp b/src/netbase.cpp index f5316965ce..83cedfb620 100644 --- a/src/netbase.cpp +++ b/src/netbase.cpp @@ -227,10 +227,7 @@ bool LookupNumeric(const char *pszName, CService& addr, int portDefault) return Lookup(pszName, addr, portDefault, false); } -/** - * Convert milliseconds to a struct timeval for select. - */ -struct timeval static MillisToTimeval(int64_t nTimeout) +struct timeval MillisToTimeval(int64_t nTimeout) { struct timeval timeout; timeout.tv_sec = nTimeout / 1000; diff --git a/src/netbase.h b/src/netbase.h index 6f8882b852..2a79f82d72 100644 --- a/src/netbase.h +++ b/src/netbase.h @@ -215,5 +215,9 @@ std::string NetworkErrorString(int err); bool CloseSocket(SOCKET& hSocket); /** Disable or enable blocking-mode for a socket */ bool SetSocketNonBlocking(SOCKET& hSocket, bool fNonBlocking); +/** + * Convert milliseconds to a struct timeval for e.g. select. + */ +struct timeval MillisToTimeval(int64_t nTimeout); #endif // BITCOIN_NETBASE_H diff --git a/src/torcontrol.cpp b/src/torcontrol.cpp new file mode 100644 index 0000000000..08644f2968 --- /dev/null +++ b/src/torcontrol.cpp @@ -0,0 +1,685 @@ +#include "torcontrol.h" +#include "utilstrencodings.h" +#include "net.h" +#include "util.h" +#include "crypto/hmac_sha256.h" + +#include <vector> +#include <deque> +#include <set> +#include <stdlib.h> + +#include <boost/function.hpp> +#include <boost/bind.hpp> +#include <boost/signals2/signal.hpp> +#include <boost/foreach.hpp> +#include <boost/algorithm/string/predicate.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 boost::function<void(TorControlConnection&)> ConnectionCB; + typedef boost::function<void(TorControlConnection &,const TorControlReply &)> ReplyHandlerCB; + + /** Create a new TorControlConnection. + */ + TorControlConnection(struct event_base *base); + ~TorControlConnection(); + + /** + * Connect to a Tor control port. + * target is address of the form host:port. + * connected is the handler that is called when connection is succesfully established. + * disconnected is a handler that is called when the connection is broken. + * Return true on success. + */ + bool Connect(const std::string &target, const ConnectionCB& connected, const ConnectionCB& disconnected); + + /** + * Disconnect from Tor control port. + */ + bool 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 */ + boost::function<void(TorControlConnection&)> connected; + /** Callback when connection lost */ + boost::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(0) +{ +} + +TorControlConnection::~TorControlConnection() +{ + if (b_conn) + bufferevent_free(b_conn); +} + +void TorControlConnection::readcb(struct bufferevent *bev, void *ctx) +{ + TorControlConnection *self = (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 NULL + while((line = evbuffer_readln(input, &n_read_out, EVBUFFER_EOL_CRLF)) != NULL) + { + 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("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 = (TorControlConnection*)ctx; + if (what & BEV_EVENT_CONNECTED) { + LogPrint("tor", "tor: Succesfully connected!\n"); + self->connected(*self); + } else if (what & (BEV_EVENT_EOF|BEV_EVENT_ERROR)) { + if (what & BEV_EVENT_ERROR) + LogPrint("tor", "tor: Error connecting to Tor control socket\n"); + else + LogPrint("tor", "tor: End of stream\n"); + self->Disconnect(); + self->disconnected(*self); + } +} + +bool TorControlConnection::Connect(const std::string &target, const ConnectionCB& connected, const ConnectionCB& disconnected) +{ + if (b_conn) + Disconnect(); + // Parse target address:port + struct sockaddr_storage connect_to_addr; + int connect_to_addrlen = sizeof(connect_to_addr); + if (evutil_parse_sockaddr_port(target.c_str(), + (struct sockaddr*)&connect_to_addr, &connect_to_addrlen)<0) { + LogPrintf("tor: Error parsing socket address %s\n", target); + 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, NULL, TorControlConnection::eventcb, this); + bufferevent_enable(b_conn, EV_READ|EV_WRITE); + this->connected = connected; + this->disconnected = disconnected; + + // Finally, connect to target + if (bufferevent_socket_connect(b_conn, (struct sockaddr*)&connect_to_addr, connect_to_addrlen) < 0) { + LogPrintf("tor: Error connecting to address %s\n", target); + return false; + } + return true; +} + +bool TorControlConnection::Disconnect() +{ + if (b_conn) + bufferevent_free(b_conn); + b_conn = 0; + return true; +} + +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=...'. + */ +static 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"'. + */ +static 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] != '=') { + key.push_back(s[ptr]); + ++ptr; + } + if (ptr == s.size()) // unexpected end of line + return std::map<std::string,std::string>(); + ++ptr; // skip '=' + if (ptr < s.size() && s[ptr] == '"') { // Quoted string + ++ptr; // skip '=' + bool escape_next = false; + while (ptr < s.size() && (!escape_next && s[ptr] != '"')) { + escape_next = (s[ptr] == '\\'); + value.push_back(s[ptr]); + ++ptr; + } + if (ptr == s.size()) // unexpected end of line + return std::map<std::string,std::string>(); + ++ptr; // skip closing '"' + /* TODO: unescape value - according to the spec this depends on the + * context, some strings use C-LogPrintf style escape codes, some + * don't. So may be better handled at the call site. + */ + } 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 occured, 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 std::string &filename, size_t maxsize=std::numeric_limits<size_t>::max()) +{ + FILE *f = fopen(filename.c_str(), "rb"); + if (f == NULL) + return std::make_pair(false,""); + std::string retval; + char buffer[128]; + size_t n; + while ((n=fread(buffer, 1, sizeof(buffer), f)) > 0) { + 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 std::string &filename, const std::string &data) +{ + FILE *f = fopen(filename.c_str(), "wb"); + if (f == NULL) + 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 a ephemeral hidden service. + */ +class TorController +{ +public: + TorController(struct event_base* base, const std::string& target); + ~TorController(); + + /** Get name fo file to store private key in */ + std::string GetPrivateKeyFile(); + + /** Reconnect, after getting disconnected */ + void Reconnect(); +private: + struct event_base* base; + std::string target; + TorControlConnection conn; + std::string private_key; + std::string service_id; + bool reconnect; + struct event *reconnect_ev; + float reconnect_timeout; + CService service; + /** Cooie 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 succesful 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& target): + base(base), + target(target), conn(base), reconnect(true), reconnect_ev(0), + reconnect_timeout(RECONNECT_TIMEOUT_START) +{ + // Start connection attempts immediately + if (!conn.Connect(target, boost::bind(&TorController::connected_cb, this, _1), + boost::bind(&TorController::disconnected_cb, this, _1) )) { + LogPrintf("tor: Initiating connection to Tor control port %s failed\n", target); + } + // Read service private key if cached + std::pair<bool,std::string> pkf = ReadBinaryFile(GetPrivateKeyFile()); + if (pkf.first) { + LogPrint("tor", "tor: Reading cached private key from %s\n", GetPrivateKeyFile()); + private_key = pkf.second; + } +} + +TorController::~TorController() +{ + if (reconnect_ev) + event_del(reconnect_ev); + if (service.IsValid()) { + RemoveLocal(service); + } +} + +void TorController::add_onion_cb(TorControlConnection& conn, const TorControlReply& reply) +{ + if (reply.code == 250) { + LogPrint("tor", "tor: ADD_ONION succesful\n"); + BOOST_FOREACH(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; + } + + service = CService(service_id+".onion", GetListenPort(), false); + LogPrintf("tor: Got service ID %s, advertizing service %s\n", service_id, service.ToString()); + if (WriteBinaryFile(GetPrivateKeyFile(), private_key)) { + LogPrint("tor", "tor: Cached service private key to %s\n", GetPrivateKeyFile()); + } else { + LogPrintf("tor: Error writing service private key to %s\n", 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("tor", "tor: Authentication succesful\n"); + // Finally - now create the service + if (private_key.empty()) // No private key, generate one + private_key = "NEW:BEST"; + // Request hidden service, redirect port. + // Note that the 'virtual' port doesn't have to be the same as our internal port, but this is just a convenient + // choice. TODO; refactor the shutdown sequence some day. + conn.Command(strprintf("ADD_ONION %s Port=%i,127.0.0.1:%i", private_key, GetListenPort(), GetListenPort()), + boost::bind(&TorController::add_onion_cb, this, _1, _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(begin_ptr(cookie), cookie.size()); + computeHash.Write(begin_ptr(clientNonce), clientNonce.size()); + computeHash.Write(begin_ptr(serverNonce), serverNonce.size()); + computeHash.Finalize(begin_ptr(computedHash)); + return computedHash; +} + +void TorController::authchallenge_cb(TorControlConnection& conn, const TorControlReply& reply) +{ + if (reply.code == 250) { + LogPrint("tor", "tor: SAFECOOKIE authentication challenge succesful\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); + std::vector<uint8_t> serverHash = ParseHex(m["SERVERHASH"]); + std::vector<uint8_t> serverNonce = ParseHex(m["SERVERNONCE"]); + LogPrint("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), boost::bind(&TorController::auth_cb, this, _1, _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 + */ + BOOST_FOREACH(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("tor", "tor: Connected to Tor version %s\n", i->second); + } + } + } + BOOST_FOREACH(const std::string &s, methods) { + LogPrint("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 = GetArg("-torpassword", ""); + if (methods.count("NULL")) { + LogPrint("tor", "tor: Using NULL authentication\n"); + conn.Command("AUTHENTICATE", boost::bind(&TorController::auth_cb, this, _1, _2)); + } else if (methods.count("SAFECOOKIE")) { + // Cookie: hexdump -e '32/1 "%02x""\n"' ~/.tor/control_auth_cookie + LogPrint("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), boost::bind(&TorController::auth_cb, this, _1, _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[0], TOR_NONCE_SIZE); + conn.Command("AUTHCHALLENGE SAFECOOKIE " + HexStr(clientNonce), boost::bind(&TorController::authchallenge_cb, this, _1, _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")) { + if (!torpassword.empty()) { + LogPrint("tor", "tor: Using HASHEDPASSWORD authentication\n"); + boost::replace_all(torpassword, "\"", "\\\""); + conn.Command("AUTHENTICATE \"" + torpassword + "\"", boost::bind(&TorController::auth_cb, this, _1, _2)); + } else { + LogPrintf("tor: Password authentication required, 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", boost::bind(&TorController::protocolinfo_cb, this, _1, _2))) + LogPrintf("tor: Error sending initial protocolinfo command\n"); +} + +void TorController::disconnected_cb(TorControlConnection& conn) +{ + // Stop advertizing service when disconnected + if (service.IsValid()) + RemoveLocal(service); + service = CService(); + if (!reconnect) + return; + LogPrintf("tor: Disconnected from Tor control port %s, trying to reconnect\n", target); + // Single-shot timer for reconnect. Use exponential backoff. + struct timeval time = MillisToTimeval(int64_t(reconnect_timeout * 1000.0)); + reconnect_ev = event_new(base, -1, 0, reconnect_cb, this); + 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(target, boost::bind(&TorController::connected_cb, this, _1), + boost::bind(&TorController::disconnected_cb, this, _1) )) { + LogPrintf("tor: Re-initiating connection to Tor control port %s failed\n", target); + } +} + +std::string TorController::GetPrivateKeyFile() +{ + return (GetDataDir() / "onion_private_key").string(); +} + +void TorController::reconnect_cb(evutil_socket_t fd, short what, void *arg) +{ + TorController *self = (TorController*)arg; + self->Reconnect(); +} + +/****** Thread ********/ +struct event_base *base; +boost::thread torControlThread; + +static void TorControlThread() +{ + TorController ctrl(base, GetArg("-torcontrol", DEFAULT_TOR_CONTROL)); + + event_base_dispatch(base); +} + +void StartTorControl(boost::thread_group& threadGroup, CScheduler& scheduler) +{ + assert(!base); +#ifdef WIN32 + evthread_use_windows_threads(); +#else + evthread_use_pthreads(); +#endif + base = event_base_new(); + if (!base) { + LogPrintf("tor: Unable to create event_base\n"); + return; + } + + torControlThread = boost::thread(boost::bind(&TraceThread<void (*)()>, "torcontrol", &TorControlThread)); +} + +void InterruptTorControl() +{ + if (base) { + LogPrintf("tor: Thread interrupt\n"); + event_base_loopbreak(base); + } +} + +void StopTorControl() +{ + if (base) { + torControlThread.join(); + event_base_free(base); + base = 0; + } +} + diff --git a/src/torcontrol.h b/src/torcontrol.h new file mode 100644 index 0000000000..72dc82c5b1 --- /dev/null +++ b/src/torcontrol.h @@ -0,0 +1,20 @@ +// Copyright (c) 2015 The Bitcoin Core developers +// Distributed under the MIT software license, see the accompanying +// file COPYING or http://www.opensource.org/licenses/mit-license.php. + +/** + * Functionality for communicating with Tor. + */ +#ifndef BITCOIN_TORCONTROL_H +#define BITCOIN_TORCONTROL_H + +#include "scheduler.h" + +extern const std::string DEFAULT_TOR_CONTROL; +static const bool DEFAULT_LISTEN_ONION = true; + +void StartTorControl(boost::thread_group& threadGroup, CScheduler& scheduler); +void InterruptTorControl(); +void StopTorControl(); + +#endif /* BITCOIN_TORCONTROL_H */ |