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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
tags/v0.15.1
Wladimir J. van der Laan 6 years ago
parent
commit
67a7949397
6 changed files with 129 additions and 79 deletions
  1. 7
    6
      src/init.cpp
  2. 104
    66
      src/netbase.cpp
  3. 13
    3
      src/netbase.h
  4. 2
    2
      src/qt/optionsmodel.cpp
  5. 1
    1
      src/rpcmisc.cpp
  6. 2
    1
      src/rpcnet.cpp

+ 7
- 6
src/init.cpp View File

@@ -301,6 +301,7 @@ std::string HelpMessage(HelpMessageMode mode)
strUsage += HelpMessageOpt("-permitbaremultisig", strprintf(_("Relay non-P2SH multisig (default: %u)"), 1));
strUsage += HelpMessageOpt("-port=<port>", strprintf(_("Listen for connections on <port> (default: %u or testnet: %u)"), 8333, 18333));
strUsage += HelpMessageOpt("-proxy=<ip:port>", _("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=<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));
#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=<category>", strprintf(_("Output debugging information (default: %u, supplying <category> 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);

+ 104
- 66
src/netbase.cpp View File

@@ -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<uint8_t> 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<char>(std::min((int)strDest.size(), 255));
strSocks5 += strDest;
strSocks5 += static_cast<char>((port >> 8) & 0xFF);
strSocks5 += static_cast<char>((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<uint8_t> 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<uint8_t> 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()

+ 13
- 3
src/netbase.h View File

@@ -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<CNetAddr>& vIP, unsigned int nMaxSolutions = 0, bool fAllowLookup = true);
bool Lookup(const char *pszName, CService& addr, int portDefault = 0, bool fAllowLookup = true);

+ 2
- 2
src/qt/optionsmodel.cpp View File

@@ -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;
}

+ 1
- 1
src/rpcmisc.cpp View File

@@ -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

+ 2
- 1
src/rpcnet.cpp View File

@@ -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;

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