From 67a79493976a3d5f5dac6ec64993fc3f415cac43 Mon Sep 17 00:00:00 2001 From: "Wladimir J. van der Laan" Date: Mon, 16 Mar 2015 16:30:49 +0100 Subject: [PATCH] privacy: Stream isolation for Tor According to Tor's extensions to the SOCKS protocol (https://gitweb.torproject.org/torspec.git/tree/socks-extensions.txt) it is possible to perform stream isolation by providing authentication to the proxy. Each set of credentials will create a new circuit, which makes it harder to correlate connections. This patch adds an option, `-proxyrandomize` (on by default) that randomizes credentials for every outgoing connection, thus creating a new circuit. 2015-03-16 15:29:59 SOCKS5 Sending proxy authentication 3842137544:3256031132 --- src/init.cpp | 13 +-- src/netbase.cpp | 170 ++++++++++++++++++++++++---------------- src/netbase.h | 16 +++- src/qt/optionsmodel.cpp | 4 +- src/rpcmisc.cpp | 2 +- src/rpcnet.cpp | 3 +- 6 files changed, 129 insertions(+), 79 deletions(-) diff --git a/src/init.cpp b/src/init.cpp index 4d9c233c8..8f52d254f 100644 --- a/src/init.cpp +++ b/src/init.cpp @@ -301,6 +301,7 @@ std::string HelpMessage(HelpMessageMode mode) strUsage += HelpMessageOpt("-permitbaremultisig", strprintf(_("Relay non-P2SH multisig (default: %u)"), 1)); strUsage += HelpMessageOpt("-port=", strprintf(_("Listen for connections on (default: %u or testnet: %u)"), 8333, 18333)); strUsage += HelpMessageOpt("-proxy=", _("Connect through SOCKS5 proxy")); + strUsage += HelpMessageOpt("-proxyrandomize", strprintf(_("Randomize credentials for every proxy connection. This enables Tor stream isolation (default: %u)"), 1)); strUsage += HelpMessageOpt("-seednode=", _("Connect to a node to retrieve peer addresses, and disconnect")); strUsage += HelpMessageOpt("-timeout=", strprintf(_("Specify connection timeout in milliseconds (minimum: 1, default: %d)"), DEFAULT_CONNECT_TIMEOUT)); #ifdef USE_UPNP @@ -351,7 +352,7 @@ std::string HelpMessage(HelpMessageMode mode) strUsage += HelpMessageOpt("-flushwallet", strprintf(_("Run a thread to flush wallet periodically (default: %u)"), 1)); strUsage += HelpMessageOpt("-stopafterblockimport", strprintf(_("Stop running after importing blocks from disk (default: %u)"), 0)); } - string debugCategories = "addrman, alert, bench, coindb, db, lock, rand, rpc, selectcoins, mempool, net"; // Don't translate these and qt below + string debugCategories = "addrman, alert, bench, coindb, db, lock, rand, rpc, selectcoins, mempool, net, proxy"; // Don't translate these and qt below if (mode == HMM_BITCOIN_QT) debugCategories += ", qt"; strUsage += HelpMessageOpt("-debug=", strprintf(_("Output debugging information (default: %u, supplying is optional)"), 0) + ". " + @@ -891,10 +892,10 @@ bool AppInit2(boost::thread_group& threadGroup) } } - CService addrProxy; + proxyType addrProxy; bool fProxy = false; if (mapArgs.count("-proxy")) { - addrProxy = CService(mapArgs["-proxy"], 9050); + addrProxy = proxyType(CService(mapArgs["-proxy"], 9050), GetArg("-proxyrandomize", true)); if (!addrProxy.IsValid()) return InitError(strprintf(_("Invalid -proxy address: '%s'"), mapArgs["-proxy"])); @@ -904,14 +905,14 @@ bool AppInit2(boost::thread_group& threadGroup) fProxy = true; } - // -onion can override normal proxy, -noonion disables tor entirely + // -onion can override normal proxy, -noonion disables connecting to .onion entirely if (!(mapArgs.count("-onion") && mapArgs["-onion"] == "0") && (fProxy || mapArgs.count("-onion"))) { - CService addrOnion; + proxyType addrOnion; if (!mapArgs.count("-onion")) addrOnion = addrProxy; else - addrOnion = CService(mapArgs["-onion"], 9050); + addrOnion = proxyType(CService(mapArgs["-onion"], 9050), GetArg("-proxyrandomize", true)); if (!addrOnion.IsValid()) return InitError(strprintf(_("Invalid -onion address: '%s'"), mapArgs["-onion"])); SetProxy(NET_TOR, addrOnion); diff --git a/src/netbase.cpp b/src/netbase.cpp index a2ac6575b..1837cfa9c 100644 --- a/src/netbase.cpp +++ b/src/netbase.cpp @@ -12,6 +12,7 @@ #include "hash.h" #include "sync.h" #include "uint256.h" +#include "random.h" #include "util.h" #include "utilstrencodings.h" @@ -38,7 +39,7 @@ using namespace std; // Settings static proxyType proxyInfo[NET_MAX]; -static CService nameProxy; +static proxyType nameProxy; static CCriticalSection cs_proxyInfos; int nConnectTimeout = DEFAULT_CONNECT_TIMEOUT; bool fNameLookup = false; @@ -285,59 +286,100 @@ bool static InterruptibleRecv(char* data, size_t len, int timeout, SOCKET& hSock return len == 0; } -bool static Socks5(string strDest, int port, SOCKET& hSocket) +struct ProxyCredentials +{ + std::string username; + std::string password; +}; + +/** Connect using SOCKS5 (as described in RFC1928) */ +bool static Socks5(string strDest, int port, const ProxyCredentials *auth, SOCKET& hSocket) { LogPrintf("SOCKS5 connecting %s\n", strDest); - if (strDest.size() > 255) - { + if (strDest.size() > 255) { CloseSocket(hSocket); return error("Hostname too long"); } - char pszSocks5Init[] = "\5\1\0"; - ssize_t nSize = sizeof(pszSocks5Init) - 1; - - ssize_t ret = send(hSocket, pszSocks5Init, nSize, MSG_NOSIGNAL); - if (ret != nSize) - { + // Accepted authentication methods + std::vector vSocks5Init; + vSocks5Init.push_back(0x05); + if (auth) { + vSocks5Init.push_back(0x02); // # METHODS + vSocks5Init.push_back(0x00); // X'00' NO AUTHENTICATION REQUIRED + vSocks5Init.push_back(0x02); // X'02' USERNAME/PASSWORD (RFC1929) + } else { + vSocks5Init.push_back(0x01); // # METHODS + vSocks5Init.push_back(0x00); // X'00' NO AUTHENTICATION REQUIRED + } + ssize_t ret = send(hSocket, (const char*)begin_ptr(vSocks5Init), vSocks5Init.size(), MSG_NOSIGNAL); + if (ret != (ssize_t)vSocks5Init.size()) { CloseSocket(hSocket); return error("Error sending to proxy"); } char pchRet1[2]; - if (!InterruptibleRecv(pchRet1, 2, SOCKS5_RECV_TIMEOUT, hSocket)) - { + if (!InterruptibleRecv(pchRet1, 2, SOCKS5_RECV_TIMEOUT, hSocket)) { CloseSocket(hSocket); return error("Error reading proxy response"); } - if (pchRet1[0] != 0x05 || pchRet1[1] != 0x00) - { + if (pchRet1[0] != 0x05) { CloseSocket(hSocket); return error("Proxy failed to initialize"); } - string strSocks5("\5\1"); - strSocks5 += '\000'; strSocks5 += '\003'; - strSocks5 += static_cast(std::min((int)strDest.size(), 255)); - strSocks5 += strDest; - strSocks5 += static_cast((port >> 8) & 0xFF); - strSocks5 += static_cast((port >> 0) & 0xFF); - ret = send(hSocket, strSocks5.data(), strSocks5.size(), MSG_NOSIGNAL); - if (ret != (ssize_t)strSocks5.size()) - { + if (pchRet1[1] == 0x02 && auth) { + // Perform username/password authentication (as described in RFC1929) + std::vector vAuth; + vAuth.push_back(0x01); + if (auth->username.size() > 255 || auth->password.size() > 255) + return error("Proxy username or password too long"); + vAuth.push_back(auth->username.size()); + vAuth.insert(vAuth.end(), auth->username.begin(), auth->username.end()); + vAuth.push_back(auth->password.size()); + vAuth.insert(vAuth.end(), auth->password.begin(), auth->password.end()); + ret = send(hSocket, (const char*)begin_ptr(vAuth), vAuth.size(), MSG_NOSIGNAL); + if (ret != (ssize_t)vAuth.size()) { + CloseSocket(hSocket); + return error("Error sending authentication to proxy"); + } + LogPrint("proxy", "SOCKS5 sending proxy authentication %s:%s\n", auth->username, auth->password); + char pchRetA[2]; + if (!InterruptibleRecv(pchRetA, 2, SOCKS5_RECV_TIMEOUT, hSocket)) { + CloseSocket(hSocket); + return error("Error reading proxy authentication response"); + } + if (pchRetA[0] != 0x01 || pchRetA[1] != 0x00) { + CloseSocket(hSocket); + return error("Proxy authentication unsuccesful"); + } + } else if (pchRet1[1] == 0x00) { + // Perform no authentication + } else { + CloseSocket(hSocket); + return error("Proxy requested wrong authentication method %02x", pchRet1[1]); + } + std::vector vSocks5; + vSocks5.push_back(0x05); // VER protocol version + vSocks5.push_back(0x01); // CMD CONNECT + vSocks5.push_back(0x00); // RSV Reserved + vSocks5.push_back(0x03); // ATYP DOMAINNAME + vSocks5.push_back(strDest.size()); // Length<=255 is checked at beginning of function + vSocks5.insert(vSocks5.end(), strDest.begin(), strDest.end()); + vSocks5.push_back((port >> 8) & 0xFF); + vSocks5.push_back((port >> 0) & 0xFF); + ret = send(hSocket, (const char*)begin_ptr(vSocks5), vSocks5.size(), MSG_NOSIGNAL); + if (ret != (ssize_t)vSocks5.size()) { CloseSocket(hSocket); return error("Error sending to proxy"); } char pchRet2[4]; - if (!InterruptibleRecv(pchRet2, 4, SOCKS5_RECV_TIMEOUT, hSocket)) - { + if (!InterruptibleRecv(pchRet2, 4, SOCKS5_RECV_TIMEOUT, hSocket)) { CloseSocket(hSocket); return error("Error reading proxy response"); } - if (pchRet2[0] != 0x05) - { + if (pchRet2[0] != 0x05) { CloseSocket(hSocket); return error("Proxy failed to accept request"); } - if (pchRet2[1] != 0x00) - { + if (pchRet2[1] != 0x00) { CloseSocket(hSocket); switch (pchRet2[1]) { @@ -352,8 +394,7 @@ bool static Socks5(string strDest, int port, SOCKET& hSocket) default: return error("Proxy error: unknown"); } } - if (pchRet2[2] != 0x00) - { + if (pchRet2[2] != 0x00) { CloseSocket(hSocket); return error("Error: malformed proxy response"); } @@ -375,13 +416,11 @@ bool static Socks5(string strDest, int port, SOCKET& hSocket) } default: CloseSocket(hSocket); return error("Error: malformed proxy response"); } - if (!ret) - { + if (!ret) { CloseSocket(hSocket); return error("Error reading from proxy"); } - if (!InterruptibleRecv(pchRet3, 2, SOCKS5_RECV_TIMEOUT, hSocket)) - { + if (!InterruptibleRecv(pchRet3, 2, SOCKS5_RECV_TIMEOUT, hSocket)) { CloseSocket(hSocket); return error("Error reading from proxy"); } @@ -471,7 +510,7 @@ bool static ConnectSocketDirectly(const CService &addrConnect, SOCKET& hSocketRe return true; } -bool SetProxy(enum Network net, CService addrProxy) { +bool SetProxy(enum Network net, const proxyType &addrProxy) { assert(net >= 0 && net < NET_MAX); if (!addrProxy.IsValid()) return false; @@ -489,7 +528,7 @@ bool GetProxy(enum Network net, proxyType &proxyInfoOut) { return true; } -bool SetNameProxy(CService addrProxy) { +bool SetNameProxy(const proxyType &addrProxy) { if (!addrProxy.IsValid()) return false; LOCK(cs_proxyInfos); @@ -497,7 +536,7 @@ bool SetNameProxy(CService addrProxy) { return true; } -bool GetNameProxy(CService &nameProxyOut) { +bool GetNameProxy(proxyType &nameProxyOut) { LOCK(cs_proxyInfos); if(!nameProxy.IsValid()) return false; @@ -513,37 +552,49 @@ bool HaveNameProxy() { bool IsProxy(const CNetAddr &addr) { LOCK(cs_proxyInfos); for (int i = 0; i < NET_MAX; i++) { - if (addr == (CNetAddr)proxyInfo[i]) + if (addr == (CNetAddr)proxyInfo[i].proxy) return true; } return false; } -bool ConnectSocket(const CService &addrDest, SOCKET& hSocketRet, int nTimeout, bool *outProxyConnectionFailed) +static bool ConnectThroughProxy(const proxyType &proxy, const std::string strDest, int port, SOCKET& hSocketRet, int nTimeout, bool *outProxyConnectionFailed) { - proxyType proxy; - if (outProxyConnectionFailed) - *outProxyConnectionFailed = false; - // no proxy needed (none set for target network) - if (!GetProxy(addrDest.GetNetwork(), proxy)) - return ConnectSocketDirectly(addrDest, hSocketRet, nTimeout); - SOCKET hSocket = INVALID_SOCKET; - // first connect to proxy server - if (!ConnectSocketDirectly(proxy, hSocket, nTimeout)) { + if (!ConnectSocketDirectly(proxy.proxy, hSocket, nTimeout)) { if (outProxyConnectionFailed) *outProxyConnectionFailed = true; return false; } // do socks negotiation - if (!Socks5(addrDest.ToStringIP(), addrDest.GetPort(), hSocket)) - return false; + if (proxy.randomize_credentials) { + ProxyCredentials random_auth; + random_auth.username = strprintf("%i", insecure_rand()); + random_auth.password = strprintf("%i", insecure_rand()); + if (!Socks5(strDest, (unsigned short)port, &random_auth, hSocket)) + return false; + } else { + if (!Socks5(strDest, (unsigned short)port, 0, hSocket)) + return false; + } hSocketRet = hSocket; return true; } +bool ConnectSocket(const CService &addrDest, SOCKET& hSocketRet, int nTimeout, bool *outProxyConnectionFailed) +{ + proxyType proxy; + if (outProxyConnectionFailed) + *outProxyConnectionFailed = false; + + if (GetProxy(addrDest.GetNetwork(), proxy)) + return ConnectThroughProxy(proxy, addrDest.ToStringIP(), addrDest.GetPort(), hSocketRet, nTimeout, outProxyConnectionFailed); + else // no proxy needed (none set for target network) + return ConnectSocketDirectly(addrDest, hSocketRet, nTimeout); +} + bool ConnectSocketByName(CService &addr, SOCKET& hSocketRet, const char *pszDest, int portDefault, int nTimeout, bool *outProxyConnectionFailed) { string strDest; @@ -554,9 +605,7 @@ bool ConnectSocketByName(CService &addr, SOCKET& hSocketRet, const char *pszDest SplitHostPort(string(pszDest), port, strDest); - SOCKET hSocket = INVALID_SOCKET; - - CService nameProxy; + proxyType nameProxy; GetNameProxy(nameProxy); CService addrResolved(CNetAddr(strDest, fNameLookup && !HaveNameProxy()), port); @@ -569,18 +618,7 @@ bool ConnectSocketByName(CService &addr, SOCKET& hSocketRet, const char *pszDest if (!HaveNameProxy()) return false; - // first connect to name proxy server - if (!ConnectSocketDirectly(nameProxy, hSocket, nTimeout)) { - if (outProxyConnectionFailed) - *outProxyConnectionFailed = true; - return false; - } - // do socks negotiation - if (!Socks5(strDest, (unsigned short)port, hSocket)) - return false; - - hSocketRet = hSocket; - return true; + return ConnectThroughProxy(nameProxy, strDest, port, hSocketRet, nTimeout, outProxyConnectionFailed); } void CNetAddr::Init() diff --git a/src/netbase.h b/src/netbase.h index b42c2dffa..6d2ca4afb 100644 --- a/src/netbase.h +++ b/src/netbase.h @@ -168,15 +168,25 @@ class CService : public CNetAddr } }; -typedef CService proxyType; +class proxyType +{ +public: + proxyType(): randomize_credentials(false) {} + proxyType(const CService &proxy, bool randomize_credentials=false): proxy(proxy), randomize_credentials(randomize_credentials) {} + + bool IsValid() const { return proxy.IsValid(); } + + CService proxy; + bool randomize_credentials; +}; enum Network ParseNetwork(std::string net); std::string GetNetworkName(enum Network net); void SplitHostPort(std::string in, int &portOut, std::string &hostOut); -bool SetProxy(enum Network net, CService addrProxy); +bool SetProxy(enum Network net, const proxyType &addrProxy); bool GetProxy(enum Network net, proxyType &proxyInfoOut); bool IsProxy(const CNetAddr &addr); -bool SetNameProxy(CService addrProxy); +bool SetNameProxy(const proxyType &addrProxy); bool HaveNameProxy(); bool LookupHost(const char *pszName, std::vector& vIP, unsigned int nMaxSolutions = 0, bool fAllowLookup = true); bool Lookup(const char *pszName, CService& addr, int portDefault = 0, bool fAllowLookup = true); diff --git a/src/qt/optionsmodel.cpp b/src/qt/optionsmodel.cpp index a169ed6b5..41d6acf35 100644 --- a/src/qt/optionsmodel.cpp +++ b/src/qt/optionsmodel.cpp @@ -335,8 +335,8 @@ bool OptionsModel::getProxySettings(QNetworkProxy& proxy) const proxyType curProxy; if (GetProxy(NET_IPV4, curProxy)) { proxy.setType(QNetworkProxy::Socks5Proxy); - proxy.setHostName(QString::fromStdString(curProxy.ToStringIP())); - proxy.setPort(curProxy.GetPort()); + proxy.setHostName(QString::fromStdString(curProxy.proxy.ToStringIP())); + proxy.setPort(curProxy.proxy.GetPort()); return true; } diff --git a/src/rpcmisc.cpp b/src/rpcmisc.cpp index 938d79513..f5bef2a07 100644 --- a/src/rpcmisc.cpp +++ b/src/rpcmisc.cpp @@ -90,7 +90,7 @@ Value getinfo(const Array& params, bool fHelp) obj.push_back(Pair("blocks", (int)chainActive.Height())); obj.push_back(Pair("timeoffset", GetTimeOffset())); obj.push_back(Pair("connections", (int)vNodes.size())); - obj.push_back(Pair("proxy", (proxy.IsValid() ? proxy.ToStringIPPort() : string()))); + obj.push_back(Pair("proxy", (proxy.IsValid() ? proxy.proxy.ToStringIPPort() : string()))); obj.push_back(Pair("difficulty", (double)GetDifficulty())); obj.push_back(Pair("testnet", Params().TestnetToBeDeprecatedFieldRPC())); #ifdef ENABLE_WALLET diff --git a/src/rpcnet.cpp b/src/rpcnet.cpp index 6306fd440..bdee5b9f2 100644 --- a/src/rpcnet.cpp +++ b/src/rpcnet.cpp @@ -371,7 +371,8 @@ static Array GetNetworksInfo() obj.push_back(Pair("name", GetNetworkName(network))); obj.push_back(Pair("limited", IsLimited(network))); obj.push_back(Pair("reachable", IsReachable(network))); - obj.push_back(Pair("proxy", proxy.IsValid() ? proxy.ToStringIPPort() : string())); + obj.push_back(Pair("proxy", proxy.IsValid() ? proxy.proxy.ToStringIPPort() : string())); + obj.push_back(Pair("proxy_randomize_credentials", proxy.randomize_credentials)); networks.push_back(obj); } return networks;