src/alert.cpp

   1 //
   2 // Alert system
   3 //
   4
   5 #include <algorithm>
   6 #include <boost/algorithm/string/classification.hpp>
   7 #include <boost/algorithm/string/replace.hpp>
   8 #include <boost/foreach.hpp>
   9 #include <map>
  10
  11 #include "alert.h"
  12 #include "key.h"
  13 #include "net.h"
  14 #include "sync.h"
  15 #include "ui_interface.h"
  16
  17 using namespace std;
  18
  19 map<uint256, CAlert> mapAlerts;
  20 CCriticalSection cs_mapAlerts;
  21
  22 static const char* pszMainKey = "04fc9702847840aaf195de8442ebecedf5b095cdbb9bc716bda9110971b28a49e0ead8564ff0db22209e0374782c093bb899692d524e9d6a6956e7c5ecbcd68284";
  23 static const char* pszTestKey = "04302390343f91cc401d56d68b123028bf52e5fca1939df127f63c6467cdf9c8e2c14b61104cf817d0b780da337893ecc4aaff1309e536162dabbdb45200ca2b0a";
  24
  25 void CUnsignedAlert::SetNull()
  26 {
  27     nVersion = 1;
  28     nRelayUntil = 0;
  29     nExpiration = 0;
  30     nID = 0;
  31     nCancel = 0;
  32     setCancel.clear();
  33     nMinVer = 0;
  34     nMaxVer = 0;
  35     setSubVer.clear();
  36     nPriority = 0;
  37
  38     strComment.clear();
  39     strStatusBar.clear();
  40     strReserved.clear();
  41 }
  42
  43 std::string CUnsignedAlert::ToString() const
  44 {
  45     std::string strSetCancel;
  46     BOOST_FOREACH(int n, setCancel)
  47         strSetCancel += strprintf("%d ", n);
  48     std::string strSetSubVer;
  49     BOOST_FOREACH(std::string str, setSubVer)
  50         strSetSubVer += "\"" + str + "\" ";
  51     return strprintf(
  52         "CAlert(\n"
  53         "    nVersion     = %d\n"
  54         "    nRelayUntil  = %"PRI64d"\n"
  55         "    nExpiration  = %"PRI64d"\n"
  56         "    nID          = %d\n"
  57         "    nCancel      = %d\n"
  58         "    setCancel    = %s\n"
  59         "    nMinVer      = %d\n"
  60         "    nMaxVer      = %d\n"
  61         "    setSubVer    = %s\n"
  62         "    nPriority    = %d\n"
  63         "    strComment   = \"%s\"\n"
  64         "    strStatusBar = \"%s\"\n"
  65         ")\n",
  66         nVersion,
  67         nRelayUntil,
  68         nExpiration,
  69         nID,
  70         nCancel,
  71         strSetCancel.c_str(),
  72         nMinVer,
  73         nMaxVer,
  74         strSetSubVer.c_str(),
  75         nPriority,
  76         strComment.c_str(),
  77         strStatusBar.c_str());
  78 }
  79
  80 void CUnsignedAlert::print() const
  81 {
  82     printf("%s", ToString().c_str());
  83 }
  84
  85 void CAlert::SetNull()
  86 {
  87     CUnsignedAlert::SetNull();
  88     vchMsg.clear();
  89     vchSig.clear();
  90 }
  91
  92 bool CAlert::IsNull() const
  93 {
  94     return (nExpiration == 0);
  95 }
  96
  97 uint256 CAlert::GetHash() const
  98 {
  99     return Hash(this->vchMsg.begin(), this->vchMsg.end());
 100 }
 101
 102 bool CAlert::IsInEffect() const
 103 {
 104     return (GetAdjustedTime() < nExpiration);
 105 }
 106
 107 bool CAlert::Cancels(const CAlert& alert) const
 108 {
 109     if (!IsInEffect())
 110         return false; // this was a no-op before 31403
 111     return (alert.nID <= nCancel || setCancel.count(alert.nID));
 112 }
 113
 114 bool CAlert::AppliesTo(int nVersion, std::string strSubVerIn) const
 115 {
 116     // TODO: rework for client-version-embedded-in-strSubVer ?
 117     return (IsInEffect() &&
 118             nMinVer <= nVersion && nVersion <= nMaxVer &&
 119             (setSubVer.empty() || setSubVer.count(strSubVerIn)));
 120 }
 121
 122 bool CAlert::AppliesToMe() const
 123 {
 124     return AppliesTo(PROTOCOL_VERSION, FormatSubVersion(CLIENT_NAME, CLIENT_VERSION, std::vector<std::string>()));
 125 }
 126
 127 bool CAlert::RelayTo(CNode* pnode) const
 128 {
 129     if (!IsInEffect())
 130         return false;
 131     // returns true if wasn't already contained in the set
 132     if (pnode->setKnown.insert(GetHash()).second)
 133     {
 134         if (AppliesTo(pnode->nVersion, pnode->strSubVer) ||
 135             AppliesToMe() ||
 136             GetAdjustedTime() < nRelayUntil)
 137         {
 138             pnode->PushMessage("alert", *this);
 139             return true;
 140         }
 141     }
 142     return false;
 143 }
 144
 145 bool CAlert::CheckSignature() const
 146 {
 147     CKey key;
 148     if (!key.SetPubKey(ParseHex(fTestNet ? pszTestKey : pszMainKey)))
 149         return error("CAlert::CheckSignature() : SetPubKey failed");
 150     if (!key.Verify(Hash(vchMsg.begin(), vchMsg.end()), vchSig))
 151         return error("CAlert::CheckSignature() : verify signature failed");
 152
 153     // Now unserialize the data
 154     CDataStream sMsg(vchMsg, SER_NETWORK, PROTOCOL_VERSION);
 155     sMsg >> *(CUnsignedAlert*)this;
 156     return true;
 157 }
 158
 159 CAlert CAlert::getAlertByHash(const uint256 &hash)
 160 {
 161     CAlert retval;
 162     {
 163         LOCK(cs_mapAlerts);
 164         map<uint256, CAlert>::iterator mi = mapAlerts.find(hash);
 165         if(mi != mapAlerts.end())
 166             retval = mi->second;
 167     }
 168     return retval;
 169 }
 170
 171 bool CAlert::ProcessAlert(bool fThread)
 172 {
 173     if (!CheckSignature())
 174         return false;
 175     if (!IsInEffect())
 176         return false;
 177
 178     // alert.nID=max is reserved for if the alert key is
 179     // compromised. It must have a pre-defined message,
 180     // must never expire, must apply to all versions,
 181     // and must cancel all previous
 182     // alerts or it will be ignored (so an attacker can't
 183     // send an "everything is OK, don't panic" version that
 184     // cannot be overridden):
 185     int maxInt = std::numeric_limits<int>::max();
 186     if (nID == maxInt)
 187     {
 188         if (!(
 189                 nExpiration == maxInt &&
 190                 nCancel == (maxInt-1) &&
 191                 nMinVer == 0 &&
 192                 nMaxVer == maxInt &&
 193                 setSubVer.empty() &&
 194                 nPriority == maxInt &&
 195                 strStatusBar == "URGENT: Alert key compromised, upgrade required"
 196                 ))
 197             return false;
 198     }
 199
 200     {
 201         LOCK(cs_mapAlerts);
 202         // Cancel previous alerts
 203         for (map<uint256, CAlert>::iterator mi = mapAlerts.begin(); mi != mapAlerts.end();)
 204         {
 205             const CAlert& alert = (*mi).second;
 206             if (Cancels(alert))
 207             {
 208                 printf("cancelling alert %d\n", alert.nID);
 209                 uiInterface.NotifyAlertChanged((*mi).first, CT_DELETED);
 210                 mapAlerts.erase(mi++);
 211             }
 212             else if (!alert.IsInEffect())
 213             {
 214                 printf("expiring alert %d\n", alert.nID);
 215                 uiInterface.NotifyAlertChanged((*mi).first, CT_DELETED);
 216                 mapAlerts.erase(mi++);
 217             }
 218             else
 219                 mi++;
 220         }
 221
 222         // Check if this alert has been cancelled
 223         BOOST_FOREACH(PAIRTYPE(const uint256, CAlert)& item, mapAlerts)
 224         {
 225             const CAlert& alert = item.second;
 226             if (alert.Cancels(*this))
 227             {
 228                 printf("alert already cancelled by %d\n", alert.nID);
 229                 return false;
 230             }
 231         }
 232
 233         // Add to mapAlerts
 234         mapAlerts.insert(make_pair(GetHash(), *this));
 235         // Notify UI and -alertnotify if it applies to me
 236         if(AppliesToMe())
 237         {
 238             uiInterface.NotifyAlertChanged(GetHash(), CT_NEW);
 239             std::string strCmd = GetArg("-alertnotify", "");
 240             if (!strCmd.empty())
 241             {
 242                 // Alert text should be plain ascii coming from a trusted source, but to
 243                 // be safe we first strip anything not in safeChars, then add single quotes around
 244                 // the whole string before passing it to the shell:
 245                 std::string singleQuote("'");
 246                 // safeChars chosen to allow simple messages/URLs/email addresses, but avoid anything
 247                 // even possibly remotely dangerous like & or >
 248                 std::string safeChars("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890 .,;_/:?@");
 249                 std::string safeStatus;
 250                 for (std::string::size_type i = 0; i < strStatusBar.size(); i++)
 251                 {
 252                     if (safeChars.find(strStatusBar[i]) != std::string::npos)
 253                         safeStatus.push_back(strStatusBar[i]);
 254                 }
 255                 safeStatus = singleQuote+safeStatus+singleQuote;
 256                 boost::replace_all(strCmd, "%s", safeStatus);
 257
 258                 if (fThread)
 259                     boost::thread t(runCommand, strCmd); // thread runs free
 260                 else
 261                     runCommand(strCmd);
 262             }
 263         }
 264     }
 265
 266     printf("accepted alert %d, AppliesToMe()=%d\n", nID, AppliesToMe());
 267     return true;
 268 }