misc changes

git-svn-id: https://bitcoin.svn.sourceforge.net/svnroot/bitcoin/trunk@131 1a98c847-1fd6-4fd8-948a-caf3550aa51b

1 files changed, 51 insertions, 25 deletions

diff --git a/script.cpp b/script.cpp
index a88f915900..b33becc113 100644
--- a/script.cpp
+++ b/script.cpp
@@ -16,12 +16,30 @@ static const CBigNum bnZero(0);
 static const CBigNum bnOne(1);

 static const CBigNum bnFalse(0);

 static const CBigNum bnTrue(1);

-static const size_t nMaxNumSize = 258;

+static const size_t nMaxNumSize = 4;

 

 

+CBigNum CastToBigNum(const valtype& vch)

+{

+    if (vch.size() > nMaxNumSize)

+        throw runtime_error("CastToBigNum() : overflow");

+    // Get rid of extra leading zeros

+    return CBigNum(CBigNum(vch).getvch());

+}

+

 bool CastToBool(const valtype& vch)

 {

-    return (CBigNum(vch) != bnZero);

+    for (int i = 0; i < vch.size(); i++)

+    {

+        if (vch[i] != 0)

+        {

+            // Can be negative zero

+            if (i == vch.size()-1 && vch[i] == 0x80)

+                return false;

+            return true;

+        }

+    }

+    return false;

 }

 

 void MakeSameSize(valtype& vch1, valtype& vch2)

@@ -68,11 +86,28 @@ bool EvalScript(vector<vector<unsigned char> >& stack, const CScript& script, co
             valtype vchPushValue;

             if (!script.GetOp(pc, opcode, vchPushValue))

                 return false;

-            if (vchPushValue.size() > 5000)

+            if (vchPushValue.size() > 520)

                 return false;

             if (opcode > OP_16 && nOpCount++ > 200)

                 return false;

 

+            if (opcode == OP_CAT ||

+                opcode == OP_SUBSTR ||

+                opcode == OP_LEFT ||

+                opcode == OP_RIGHT ||

+                opcode == OP_INVERT ||

+                opcode == OP_AND ||

+                opcode == OP_OR ||

+                opcode == OP_XOR ||

+                opcode == OP_2MUL ||

+                opcode == OP_2DIV ||

+                opcode == OP_MUL ||

+                opcode == OP_DIV ||

+                opcode == OP_MOD ||

+                opcode == OP_LSHIFT ||

+                opcode == OP_RSHIFT)

+                return false;

+

             if (fExec && opcode <= OP_PUSHDATA4)

                 stack.push_back(vchPushValue);

             else if (fExec || (OP_IF <= opcode && opcode <= OP_ENDIF))

@@ -332,7 +367,7 @@ bool EvalScript(vector<vector<unsigned char> >& stack, const CScript& script, co
                     // (xn ... x2 x1 x0 n - ... x2 x1 x0 xn)

                     if (stack.size() < 2)

                         return false;

-                    int n = CBigNum(stacktop(-1)).getint();

+                    int n = CastToBigNum(stacktop(-1)).getint();

                     stack.pop_back();

                     if (n < 0 || n >= stack.size())

                         return false;

@@ -387,7 +422,7 @@ bool EvalScript(vector<vector<unsigned char> >& stack, const CScript& script, co
                     valtype& vch2 = stacktop(-1);

                     vch1.insert(vch1.end(), vch2.begin(), vch2.end());

                     stack.pop_back();

-                    if (stacktop(-1).size() > 5000)

+                    if (stacktop(-1).size() > 520)

                         return false;

                 }

                 break;

@@ -398,8 +433,8 @@ bool EvalScript(vector<vector<unsigned char> >& stack, const CScript& script, co
                     if (stack.size() < 3)

                         return false;

                     valtype& vch = stacktop(-3);

-                    int nBegin = CBigNum(stacktop(-2)).getint();

-                    int nEnd = nBegin + CBigNum(stacktop(-1)).getint();

+                    int nBegin = CastToBigNum(stacktop(-2)).getint();

+                    int nEnd = nBegin + CastToBigNum(stacktop(-1)).getint();

                     if (nBegin < 0 || nEnd < nBegin)

                         return false;

                     if (nBegin > vch.size())

@@ -420,7 +455,7 @@ bool EvalScript(vector<vector<unsigned char> >& stack, const CScript& script, co
                     if (stack.size() < 2)

                         return false;

                     valtype& vch = stacktop(-2);

-                    int nSize = CBigNum(stacktop(-1)).getint();

+                    int nSize = CastToBigNum(stacktop(-1)).getint();

                     if (nSize < 0)

                         return false;

                     if (nSize > vch.size())

@@ -531,9 +566,7 @@ bool EvalScript(vector<vector<unsigned char> >& stack, const CScript& script, co
                     // (in -- out)

                     if (stack.size() < 1)

                         return false;

-                    if (stacktop(-1).size() > nMaxNumSize)

-                        return false;

-                    CBigNum bn(stacktop(-1));

+                    CBigNum bn = CastToBigNum(stacktop(-1));

                     switch (opcode)

                     {

                     case OP_1ADD:       bn += bnOne; break;

@@ -572,11 +605,8 @@ bool EvalScript(vector<vector<unsigned char> >& stack, const CScript& script, co
                     // (x1 x2 -- out)

                     if (stack.size() < 2)

                         return false;

-                    if (stacktop(-2).size() > nMaxNumSize ||

-                        stacktop(-1).size() > nMaxNumSize)

-                        return false;

-                    CBigNum bn1(stacktop(-2));

-                    CBigNum bn2(stacktop(-1));

+                    CBigNum bn1 = CastToBigNum(stacktop(-2));

+                    CBigNum bn2 = CastToBigNum(stacktop(-1));

                     CBigNum bn;

                     switch (opcode)

                     {

@@ -646,13 +676,9 @@ bool EvalScript(vector<vector<unsigned char> >& stack, const CScript& script, co
                     // (x min max -- out)

                     if (stack.size() < 3)

                         return false;

-                    if (stacktop(-3).size() > nMaxNumSize ||

-                        stacktop(-2).size() > nMaxNumSize ||

-                        stacktop(-1).size() > nMaxNumSize)

-                        return false;

-                    CBigNum bn1(stacktop(-3));

-                    CBigNum bn2(stacktop(-2));

-                    CBigNum bn3(stacktop(-1));

+                    CBigNum bn1 = CastToBigNum(stacktop(-3));

+                    CBigNum bn2 = CastToBigNum(stacktop(-2));

+                    CBigNum bn3 = CastToBigNum(stacktop(-1));

                     bool fValue = (bn2 <= bn1 && bn1 < bn3);

                     stack.pop_back();

                     stack.pop_back();

@@ -748,7 +774,7 @@ bool EvalScript(vector<vector<unsigned char> >& stack, const CScript& script, co
                     if (stack.size() < i)

                         return false;

 

-                    int nKeysCount = CBigNum(stacktop(-i)).getint();

+                    int nKeysCount = CastToBigNum(stacktop(-i)).getint();

                     if (nKeysCount < 0)

                         return false;

                     int ikey = ++i;

@@ -756,7 +782,7 @@ bool EvalScript(vector<vector<unsigned char> >& stack, const CScript& script, co
                     if (stack.size() < i)

                         return false;

 

-                    int nSigsCount = CBigNum(stacktop(-i)).getint();

+                    int nSigsCount = CastToBigNum(stacktop(-i)).getint();

                     if (nSigsCount < 0 || nSigsCount > nKeysCount)

                         return false;

                     int isig = ++i;