Use script matching rather than destination matching for watch-only.

This changes the keystore data format, wallet format and IsMine logic
to detect watch-only outputs based on direct script matching rather
than first trying to convert outputs to destinations (addresses).

The reason is that we don't know how the software that has the spending
keys works. It may support the same types of scripts as us, but that is
not guaranteed. Furthermore, it removes the ambiguity between addresses
used as identifiers for output scripts or identifiers for public keys.

One practical implication is that adding a normal pay-to-pubkey-hash
address via importaddress will not cause payments to the corresponding
full public key to be detected as IsMine. If that is wanted, add those
scripts directly (importaddress now also accepts any hex-encoded script).

Conflicts:
	src/wallet.cpp

src/keystore.cpp

@@ -59,14 +59,14 @@ bool CBasicKeyStore::GetCScript(const CScriptID &hash, CScript& redeemScriptOut)
     return false;
 }
 
-bool CBasicKeyStore::AddWatchOnly(const CTxDestination &dest)
+bool CBasicKeyStore::AddWatchOnly(const CScript &dest)
 {
     LOCK(cs_KeyStore);
     setWatchOnly.insert(dest);
     return true;
 }
 
-bool CBasicKeyStore::HaveWatchOnly(const CTxDestination &dest) const
+bool CBasicKeyStore::HaveWatchOnly(const CScript &dest) const
 {
     LOCK(cs_KeyStore);
     return setWatchOnly.count(dest) > 0;

src/keystore.h

@@ -48,13 +48,13 @@ public:
     virtual bool GetCScript(const CScriptID &hash, CScript& redeemScriptOut) const =0;
 
     // Support for Watch-only addresses
-    virtual bool AddWatchOnly(const CTxDestination &dest) =0;
-    virtual bool HaveWatchOnly(const CTxDestination &dest) const =0;
+    virtual bool AddWatchOnly(const CScript &dest) =0;
+    virtual bool HaveWatchOnly(const CScript &dest) const =0;
 };
 
 typedef std::map<CKeyID, CKey> KeyMap;
 typedef std::map<CScriptID, CScript > ScriptMap;
-typedef std::set<CTxDestination> WatchOnlySet;
+typedef std::set<CScript> WatchOnlySet;
 
 /** Basic key store, that keeps keys in an address->secret map */
 class CBasicKeyStore : public CKeyStore
@@ -105,8 +105,8 @@ public:
     virtual bool HaveCScript(const CScriptID &hash) const;
     virtual bool GetCScript(const CScriptID &hash, CScript& redeemScriptOut) const;
 
-    virtual bool AddWatchOnly(const CTxDestination &dest);
-    virtual bool HaveWatchOnly(const CTxDestination &dest) const;
+    virtual bool AddWatchOnly(const CScript &dest);
+    virtual bool HaveWatchOnly(const CScript &dest) const;
 };
 
 typedef std::vector<unsigned char, secure_allocator<unsigned char> > CKeyingMaterial;

src/rpcdump.cpp

@@ -138,13 +138,19 @@ Value importaddress(const Array& params, bool fHelp)
     if (fHelp || params.size() < 1 || params.size() > 3)
         throw runtime_error(
             "importaddress <address> [label] [rescan=true]\n"
-            "Adds an address that can be watched as if it were in your wallet but cannot be used to spend.");
+            "Adds an address or script (in hex) that can be watched as if it were in your wallet but cannot be used to spend.");
+
+    CScript script;
 
     CBitcoinAddress address(params[0].get_str());
-    if (!address.IsValid())
-        throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Invalid Bitcoin address");
-    CTxDestination dest;
-    dest = address.Get();
+    if (address.IsValid()) {
+        script.SetDestination(address.Get());
+    } else if (IsHex(params[0].get_str())) {
+        std::vector<unsigned char> data(ParseHex(params[0].get_str()));
+        script = CScript(data.begin(), data.end());
+    } else {
+        throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Invalid Bitcoin address or script");
+    }
 
     string strLabel = "";
     if (params.size() > 1)
@@ -159,15 +165,16 @@ Value importaddress(const Array& params, bool fHelp)
         LOCK2(cs_main, pwalletMain->cs_wallet);
 
         // add to address book or update label
-        pwalletMain->SetAddressBook(dest, strLabel, "receive");
+        if (address.IsValid())
+            pwalletMain->SetAddressBook(address.Get(), strLabel, "receive");
 
         // Don't throw error in case an address is already there
-        if (pwalletMain->HaveWatchOnly(dest))
+        if (pwalletMain->HaveWatchOnly(script))
             return Value::null;
 
         pwalletMain->MarkDirty();
 
-        if (!pwalletMain->AddWatchOnly(dest))
+        if (!pwalletMain->AddWatchOnly(script))
             throw JSONRPCError(RPC_WALLET_ERROR, "Error adding address to wallet");
 
         if (fRescan)

src/script.cpp

@@ -1458,11 +1458,9 @@ public:
 
 isminetype IsMine(const CKeyStore &keystore, const CTxDestination& dest)
 {
-    if (boost::apply_visitor(CKeyStoreIsMineVisitor(&keystore), dest))
-        return MINE_SPENDABLE;
-    if (keystore.HaveWatchOnly(dest))
-        return MINE_WATCH_ONLY;
-    return MINE_NO;
+    CScript script;
+    script.SetDestination(dest);
+    return IsMine(keystore, script);
 }
 
 isminetype IsMine(const CKeyStore &keystore, const CScript& scriptPubKey)
@@ -1470,7 +1468,7 @@ isminetype IsMine(const CKeyStore &keystore, const CScript& scriptPubKey)
     vector<valtype> vSolutions;
     txnouttype whichType;
     if (!Solver(scriptPubKey, whichType, vSolutions)) {
-        if (keystore.HaveWatchOnly(scriptPubKey.GetID()))
+        if (keystore.HaveWatchOnly(scriptPubKey))
             return MINE_WATCH_ONLY;
         return MINE_NO;
     }
@@ -1485,15 +1483,11 @@ isminetype IsMine(const CKeyStore &keystore, const CScript& scriptPubKey)
         keyID = CPubKey(vSolutions[0]).GetID();
         if (keystore.HaveKey(keyID))
             return MINE_SPENDABLE;
-        if (keystore.HaveWatchOnly(keyID))
-            return MINE_WATCH_ONLY;
         break;
     case TX_PUBKEYHASH:
         keyID = CKeyID(uint160(vSolutions[0]));
         if (keystore.HaveKey(keyID))
             return MINE_SPENDABLE;
-        if (keystore.HaveWatchOnly(keyID))
-            return MINE_WATCH_ONLY;
         break;
     case TX_SCRIPTHASH:
     {
@@ -1501,11 +1495,9 @@ isminetype IsMine(const CKeyStore &keystore, const CScript& scriptPubKey)
         CScript subscript;
         if (keystore.GetCScript(scriptID, subscript)) {
             isminetype ret = IsMine(keystore, subscript);
-            if (ret)
+            if (ret == MINE_SPENDABLE)
                 return ret;
         }
-        if (keystore.HaveWatchOnly(scriptID))
-            return MINE_WATCH_ONLY;
         break;
     }
     case TX_MULTISIG:
@@ -1522,7 +1514,7 @@ isminetype IsMine(const CKeyStore &keystore, const CScript& scriptPubKey)
     }
     }
 
-    if (keystore.HaveWatchOnly(scriptPubKey.GetID()))
+    if (keystore.HaveWatchOnly(scriptPubKey))
         return MINE_WATCH_ONLY;
     return MINE_NO;
 }

src/wallet.cpp

@@ -145,7 +145,7 @@ bool CWallet::LoadCScript(const CScript& redeemScript)
     return CCryptoKeyStore::AddCScript(redeemScript);
 }
 
-bool CWallet::AddWatchOnly(const CTxDestination &dest)
+bool CWallet::AddWatchOnly(const CScript &dest)
 {
     if (!CCryptoKeyStore::AddWatchOnly(dest))
         return false;
@@ -155,9 +155,8 @@ bool CWallet::AddWatchOnly(const CTxDestination &dest)
     return CWalletDB(strWalletFile).WriteWatchOnly(dest);
 }
 
-bool CWallet::LoadWatchOnly(const CTxDestination &dest)
+bool CWallet::LoadWatchOnly(const CScript &dest)
 {
-    LogPrintf("Loaded %s!\n", CBitcoinAddress(dest).ToString().c_str());
     return CCryptoKeyStore::AddWatchOnly(dest);
 }
 
@@ -729,17 +728,19 @@ int64_t CWallet::GetDebit(const CTxIn &txin, const isminefilter& filter) const
 
 bool CWallet::IsChange(const CTxOut& txout) const
 {
-    CTxDestination address;
-
     // TODO: fix handling of 'change' outputs. The assumption is that any
-    // payment to a TX_PUBKEYHASH that is mine but isn't in the address book
+    // payment to a script that is ours, but is not in the address book
     // is change. That assumption is likely to break when we implement multisignature
     // wallets that return change back into a multi-signature-protected address;
     // a better way of identifying which outputs are 'the send' and which are
     // 'the change' will need to be implemented (maybe extend CWalletTx to remember
     // which output, if any, was change).
-    if (ExtractDestination(txout.scriptPubKey, address) && ::IsMine(*this, address) == MINE_SPENDABLE)
+    if (::IsMine(*this, txout.scriptPubKey))
     {
+        CTxDestination address;
+        if (!ExtractDestination(txout.scriptPubKey, address))
+            return true;
+
         LOCK(cs_wallet);
         if (!mapAddressBook.count(address))
             return true;

src/wallet.h

@@ -227,9 +227,9 @@ public:
     bool GetDestData(const CTxDestination &dest, const std::string &key, std::string *value) const;
 
     // Adds a watch-only address to the store, and saves it to disk.
-    bool AddWatchOnly(const CTxDestination &dest);
+    bool AddWatchOnly(const CScript &dest);
     // Adds a watch-only address to the store, without saving it to disk (used by LoadWallet)
-    bool LoadWatchOnly(const CTxDestination &dest);
+    bool LoadWatchOnly(const CScript &dest);
 
     bool Unlock(const SecureString& strWalletPassphrase);
     bool ChangeWalletPassphrase(const SecureString& strOldWalletPassphrase, const SecureString& strNewWalletPassphrase);

src/walletdb.cpp

@@ -112,10 +112,10 @@ bool CWalletDB::WriteCScript(const uint160& hash, const CScript& redeemScript)
     return Write(std::make_pair(std::string("cscript"), hash), redeemScript, false);
 }
 
-bool CWalletDB::WriteWatchOnly(const CTxDestination &dest)
+bool CWalletDB::WriteWatchOnly(const CScript &dest)
 {
     nWalletDBUpdated++;
-    return Write(std::make_pair(std::string("watch"), CBitcoinAddress(dest).ToString()), '1');
+    return Write(std::make_pair(std::string("watchs"), dest), '1');
 }
 
 bool CWalletDB::WriteBestBlock(const CBlockLocator& locator)
@@ -410,14 +410,14 @@ ReadKeyValue(CWallet* pwallet, CDataStream& ssKey, CDataStream& ssValue,
                     wss.fAnyUnordered = true;
             }
         }
-        else if (strType == "watch")
+        else if (strType == "watchs")
         {
-            std::string strAddress;
-            ssKey >> strAddress;
+            CScript script;
+            ssKey >> script;
             char fYes;
             ssValue >> fYes;
             if (fYes == '1')
-                pwallet->LoadWatchOnly(CBitcoinAddress(strAddress).Get());
+                pwallet->LoadWatchOnly(script);
 
             // Watch-only addresses have no birthday information for now,
             // so set the wallet birthday to the beginning of time.

src/walletdb.h

@@ -94,7 +94,7 @@ public:
 
     bool WriteCScript(const uint160& hash, const CScript& redeemScript);
 
-    bool WriteWatchOnly(const CTxDestination &dest);
+    bool WriteWatchOnly(const CScript &script);
 
     bool WriteBestBlock(const CBlockLocator& locator);
     bool ReadBestBlock(CBlockLocator& locator);