Merge branch 'master' of github.com:novacoin-project/novacoin
[novacoin.git] / src / script.cpp
index c7c2b29..ceacdc3 100644 (file)
@@ -148,6 +148,8 @@ const char* GetOpName(opcodetype opcode)
     case OP_ENDIF                  : return "OP_ENDIF";
     case OP_VERIFY                 : return "OP_VERIFY";
     case OP_RETURN                 : return "OP_RETURN";
+    case OP_CHECKLOCKTIMEVERIFY    : return "OP_CHECKLOCKTIMEVERIFY";
+    case OP_CHECKSEQUENCEVERIFY    : return "OP_CHECKSEQUENCEVERIFY";
 
     // stack ops
     case OP_TOALTSTACK             : return "OP_TOALTSTACK";
@@ -230,8 +232,6 @@ const char* GetOpName(opcodetype opcode)
 
     // expanson
     case OP_NOP1                   : return "OP_NOP1";
-    case OP_NOP2                   : return "OP_NOP2";
-    case OP_NOP3                   : return "OP_NOP3";
     case OP_NOP4                   : return "OP_NOP4";
     case OP_NOP5                   : return "OP_NOP5";
     case OP_NOP6                   : return "OP_NOP6";
@@ -294,7 +294,7 @@ bool IsDERSignature(const valtype &vchSig, bool fWithHashType, bool fCheckLow) {
     if (5 + nLenR >= vchSig.size())
         return error("Non-canonical signature: S length misplaced");
     unsigned int nLenS = vchSig[5+nLenR];
-    if ((unsigned long)(nLenR + nLenS + (fWithHashType ? 7 : 6)) != vchSig.size())
+    if ((nLenR + nLenS + (fWithHashType ? 7 : 6)) != vchSig.size())
         return error("Non-canonical signature: R+S length mismatch");
 
     const unsigned char *R = &vchSig[4];
@@ -338,6 +338,83 @@ bool IsCanonicalSignature(const valtype &vchSig, unsigned int flags) {
     return IsDERSignature(vchSig, true, (flags & SCRIPT_VERIFY_LOW_S) != 0);
 }
 
+bool CheckLockTime(const int64_t& nLockTime, const CTransaction &txTo, unsigned int nIn)
+{
+    // There are two kinds of nLockTime: lock-by-blockheight
+    // and lock-by-blocktime, distinguished by whether
+    // nLockTime < LOCKTIME_THRESHOLD.
+    //
+    // We want to compare apples to apples, so fail the script
+    // unless the type of nLockTime being tested is the same as
+    // the nLockTime in the transaction.
+    if (!(
+        (txTo.nLockTime <  LOCKTIME_THRESHOLD && nLockTime <  LOCKTIME_THRESHOLD) ||
+        (txTo.nLockTime >= LOCKTIME_THRESHOLD && nLockTime >= LOCKTIME_THRESHOLD)
+    ))
+        return false;
+
+    // Now that we know we're comparing apples-to-apples, the
+    // comparison is a simple numeric one.
+    if (nLockTime > (int64_t)txTo.nLockTime)
+        return false;
+
+    // Finally the nLockTime feature can be disabled and thus
+    // CHECKLOCKTIMEVERIFY bypassed if every txin has been
+    // finalized by setting nSequence to maxint. The
+    // transaction would be allowed into the blockchain, making
+    // the opcode ineffective.
+    //
+    // Testing if this vin is not final is sufficient to
+    // prevent this condition. Alternatively we could test all
+    // inputs, but testing just this input minimizes the data
+    // required to prove correct CHECKLOCKTIMEVERIFY execution.
+    if (SEQUENCE_FINAL == txTo.vin[nIn].nSequence)
+        return false;
+
+    return true;
+}
+
+bool CheckSequence(const int64_t& nSequence, const CTransaction &txTo, unsigned int nIn)
+{
+    // Relative lock times are supported by comparing the passed
+    // in operand to the sequence number of the input.
+    const int64_t txToSequence = (int64_t)txTo.vin[nIn].nSequence;
+
+    // Sequence numbers with their most significant bit set are not
+    // consensus constrained. Testing that the transaction's sequence
+    // number do not have this bit set prevents using this property
+    // to get around a CHECKSEQUENCEVERIFY check.
+    if (txToSequence & SEQUENCE_LOCKTIME_DISABLE_FLAG)
+        return false;
+
+    // Mask off any bits that do not have consensus-enforced meaning
+    // before doing the integer comparisons
+    const uint32_t nLockTimeMask = SEQUENCE_LOCKTIME_TYPE_FLAG | SEQUENCE_LOCKTIME_MASK;
+    const int64_t txToSequenceMasked = txToSequence & nLockTimeMask;
+    const int64_t nSequenceMasked = nSequence & nLockTimeMask;
+
+    // There are two kinds of nSequence: lock-by-blockheight
+    // and lock-by-blocktime, distinguished by whether
+    // nSequenceMasked < CTxIn::SEQUENCE_LOCKTIME_TYPE_FLAG.
+    //
+    // We want to compare apples to apples, so fail the script
+    // unless the type of nSequenceMasked being tested is the same as
+    // the nSequenceMasked in the transaction.
+    if (!(
+        (txToSequenceMasked <  SEQUENCE_LOCKTIME_TYPE_FLAG && nSequenceMasked <  SEQUENCE_LOCKTIME_TYPE_FLAG) ||
+        (txToSequenceMasked >= SEQUENCE_LOCKTIME_TYPE_FLAG && nSequenceMasked >= SEQUENCE_LOCKTIME_TYPE_FLAG)
+    )) {
+        return false;
+    }
+
+    // Now that we know we're comparing apples-to-apples, the
+    // comparison is a simple numeric one.
+    if (nSequenceMasked > txToSequenceMasked)
+        return false;
+
+    return true;
+}
+
 bool EvalScript(vector<vector<unsigned char> >& stack, const CScript& script, const CTransaction& txTo, unsigned int nIn, unsigned int flags, int nHashType)
 {
     CAutoBN_CTX pctx;
@@ -422,7 +499,7 @@ bool EvalScript(vector<vector<unsigned char> >& stack, const CScript& script, co
                 // Control
                 //
                 case OP_NOP:
-                case OP_NOP1: case OP_NOP2: case OP_NOP3: case OP_NOP4: case OP_NOP5:
+                case OP_NOP1: case OP_NOP4: case OP_NOP5:
                 case OP_NOP6: case OP_NOP7: case OP_NOP8: case OP_NOP9: case OP_NOP10:
                 break;
 
@@ -481,6 +558,67 @@ bool EvalScript(vector<vector<unsigned char> >& stack, const CScript& script, co
                 }
                 break;
 
+                case OP_CHECKLOCKTIMEVERIFY:
+                {
+                    // CHECKLOCKTIMEVERIFY
+                    //
+                    // (nLockTime -- nLockTime)
+                    if (!(flags & SCRIPT_VERIFY_CHECKLOCKTIMEVERIFY)) {
+                        // treat as a NOP2 if not enabled
+                        break;
+                    }
+
+                    if (stack.size() < 1)
+                        return false;
+
+                    CBigNum nLockTime = CastToBigNum(stacktop(-1));
+
+                    // In the rare event that the argument may be < 0 due to
+                    // some arithmetic being done first, you can always use
+                    // 0 MAX CHECKLOCKTIMEVERIFY.
+                    if (nLockTime < 0)
+                        return false;
+
+                    // Actually compare the specified lock time with the transaction.
+                    if (!CheckLockTime(nLockTime.getuint64(), txTo, nIn))
+                        return false;
+
+                    break;
+                }
+
+                case OP_CHECKSEQUENCEVERIFY:
+                {
+                    if (!(flags & SCRIPT_VERIFY_CHECKSEQUENCEVERIFY)) {
+                        // treat as a NOP3 not enabled
+                        break;
+                    }
+
+                    if (stack.size() < 1)
+                        return false;
+
+                    // nSequence, like nLockTime, is a 32-bit unsigned integer
+                    // field. See the comment in CHECKLOCKTIMEVERIFY regarding
+                    // 5-byte numeric operands.
+                    CBigNum nSequence = CastToBigNum(stacktop(-1));
+
+                    // In the rare event that the argument may be < 0 due to
+                    // some arithmetic being done first, you can always use
+                    // 0 MAX CHECKSEQUENCEVERIFY.
+                    if (nSequence < 0)
+                        return false;
+
+                    // To provide for future soft-fork extensibility, if the
+                    // operand has the disabled lock-time flag set,
+                    // CHECKSEQUENCEVERIFY behaves as a NOP.
+                    if ((nSequence.getint32() & SEQUENCE_LOCKTIME_DISABLE_FLAG) != 0)
+                        break;
+
+                    // Compare the specified sequence number with the input.
+                    if (!CheckSequence(nSequence.getuint64(), txTo, nIn))
+                        return false;
+
+                    break;
+                }
 
                 //
                 // Stack ops
@@ -1211,6 +1349,8 @@ bool Solver(const CScript& scriptPubKey, txnouttype& typeRet, vector<vector<unsi
         mTemplates.insert(make_pair(TX_NULL_DATA, CScript() << OP_RETURN << OP_SMALLDATA));
     }
 
+    vSolutionsRet.clear();
+
     // Shortcut for pay-to-script-hash, which are more constrained than the other types:
     // it is always OP_HASH160 20 [20 byte hash] OP_EQUAL
     if (scriptPubKey.IsPayToScriptHash())
@@ -1221,6 +1361,16 @@ bool Solver(const CScript& scriptPubKey, txnouttype& typeRet, vector<vector<unsi
         return true;
     }
 
+    // Provably prunable, data-carrying output
+    //
+    // So long as script passes the IsUnspendable() test and all but the first
+    // byte passes the IsPushOnly() test we don't care what exactly is in the
+    // script.
+    if (scriptPubKey.size() >= 1 && scriptPubKey[0] == OP_RETURN && scriptPubKey.IsPushOnly(scriptPubKey.begin()+1)) {
+        typeRet = TX_NULL_DATA;
+        return true;
+    }
+
     // Scan templates
     const CScript& script1 = scriptPubKey;
     BOOST_FOREACH(const PAIRTYPE(txnouttype, CScript)& tplate, mTemplates)
@@ -1293,6 +1443,20 @@ bool Solver(const CScript& scriptPubKey, txnouttype& typeRet, vector<vector<unsi
                 else
                     break;
             }
+            else if (opcode2 == OP_INTEGER)
+            {   // Up to four-byte integer pushed onto vSolutions
+                try
+                {
+                    CBigNum bnVal = CastToBigNum(vch1);
+                    if (bnVal <= 16)
+                        break; // It's better to use OP_0 ... OP_16 for small integers.
+                    vSolutionsRet.push_back(vch1);
+                }
+                catch(...)
+                {
+                    break;
+                }
+            }
             else if (opcode2 == OP_SMALLDATA)
             {
                 // small pushdata, <= 1024 bytes
@@ -1972,13 +2136,25 @@ void CScript::SetDestination(const CTxDestination& dest)
     boost::apply_visitor(CScriptVisitor(this), dest);
 }
 
-void CScript::SetDestination(const CPubKey& R, CPubKey& pubKeyVariant)
+void CScript::SetAddress(const CBitcoinAddress& dest)
 {
     this->clear();
-    *this << pubKeyVariant << R << OP_DROP << OP_CHECKSIG;
+    if (dest.IsScript())
+        *this << OP_HASH160 << dest.GetData() << OP_EQUAL;
+    else if (dest.IsPubKey())
+        *this << OP_DUP << OP_HASH160 << dest.GetData() << OP_EQUALVERIFY << OP_CHECKSIG;
+    else if (dest.IsPair()) {
+        // Pubkey pair address, going to generate
+        //   new one-time public key.
+        CMalleablePubKey mpk;
+        if (!mpk.setvch(dest.GetData()))
+            return;
+        CPubKey R, pubKeyVariant;
+        mpk.GetVariant(R, pubKeyVariant);
+        *this << pubKeyVariant << R << OP_DROP << OP_CHECKSIG;
+    }
 }
 
-
 void CScript::SetMultisig(int nRequired, const std::vector<CKey>& keys)
 {
     this->clear();