1 files changed, 155 insertions, 43 deletions

diff --git a/src/script.h b/src/script.h
index 657ac0b388..1742ce81f8 100644
--- a/src/script.h
+++ b/src/script.h
@@ -6,7 +6,6 @@
 #ifndef H_BITCOIN_SCRIPT
 #define H_BITCOIN_SCRIPT
 
-#include "bignum.h"
 #include "key.h"
 #include "util.h"
 
@@ -25,6 +24,155 @@ class CTransaction;
 static const unsigned int MAX_SCRIPT_ELEMENT_SIZE = 520; // bytes
 static const unsigned int MAX_OP_RETURN_RELAY = 40;      // bytes
 
+class scriptnum_error : public std::runtime_error
+{
+public:
+    explicit scriptnum_error(const std::string& str) : std::runtime_error(str) {}
+};
+
+class CScriptNum
+{
+// Numeric opcodes (OP_1ADD, etc) are restricted to operating on 4-byte integers.
+// The semantics are subtle, though: operands must be in the range [-2^31 +1...2^31 -1],
+// but results may overflow (and are valid as long as they are not used in a subsequent
+// numeric operation). CScriptNum enforces those semantics by storing results as
+// an int64 and allowing out-of-range values to be returned as a vector of bytes but
+// throwing an exception if arithmetic is done or the result is interpreted as an integer.
+public:
+
+    explicit CScriptNum(const int64_t& n)
+    {
+        m_value = n;
+    }
+
+    explicit CScriptNum(const std::vector<unsigned char>& vch)
+    {
+        if (vch.size() > nMaxNumSize)
+            throw scriptnum_error("CScriptNum(const std::vector<unsigned char>&) : overflow");
+        m_value = set_vch(vch);
+    }
+
+    inline bool operator==(const int64_t& rhs) const    { return m_value == rhs; }
+    inline bool operator!=(const int64_t& rhs) const    { return m_value != rhs; }
+    inline bool operator<=(const int64_t& rhs) const    { return m_value <= rhs; }
+    inline bool operator< (const int64_t& rhs) const    { return m_value <  rhs; }
+    inline bool operator>=(const int64_t& rhs) const    { return m_value >= rhs; }
+    inline bool operator> (const int64_t& rhs) const    { return m_value >  rhs; }
+
+    inline bool operator==(const CScriptNum& rhs) const { return operator==(rhs.m_value); }
+    inline bool operator!=(const CScriptNum& rhs) const { return operator!=(rhs.m_value); }
+    inline bool operator<=(const CScriptNum& rhs) const { return operator<=(rhs.m_value); }
+    inline bool operator< (const CScriptNum& rhs) const { return operator< (rhs.m_value); }
+    inline bool operator>=(const CScriptNum& rhs) const { return operator>=(rhs.m_value); }
+    inline bool operator> (const CScriptNum& rhs) const { return operator> (rhs.m_value); }
+
+    inline CScriptNum operator+(   const int64_t& rhs)    const { return CScriptNum(m_value + rhs);}
+    inline CScriptNum operator-(   const int64_t& rhs)    const { return CScriptNum(m_value - rhs);}
+    inline CScriptNum operator+(   const CScriptNum& rhs) const { return operator+(rhs.m_value);   }
+    inline CScriptNum operator-(   const CScriptNum& rhs) const { return operator-(rhs.m_value);   }
+
+    inline CScriptNum& operator+=( const CScriptNum& rhs)       { return operator+=(rhs.m_value);  }
+    inline CScriptNum& operator-=( const CScriptNum& rhs)       { return operator-=(rhs.m_value);  }
+
+    inline CScriptNum operator-()                         const
+    {
+        assert(m_value != std::numeric_limits<int64_t>::min());
+        return CScriptNum(-m_value);
+    }
+
+    inline CScriptNum& operator=( const int64_t& rhs)
+    {
+        m_value = rhs;
+        return *this;
+    }
+
+    inline CScriptNum& operator+=( const int64_t& rhs)
+    {
+        assert(rhs == 0 || (rhs > 0 && m_value <= std::numeric_limits<int64_t>::max() - rhs) ||
+                           (rhs < 0 && m_value >= std::numeric_limits<int64_t>::min() - rhs));
+        m_value += rhs;
+        return *this;
+    }
+
+    inline CScriptNum& operator-=( const int64_t& rhs)
+    {
+        assert(rhs == 0 || (rhs > 0 && m_value >= std::numeric_limits<int64_t>::min() + rhs) ||
+                           (rhs < 0 && m_value <= std::numeric_limits<int64_t>::max() + rhs));
+        m_value -= rhs;
+        return *this;
+    }
+
+    int getint() const
+    {
+        if (m_value > std::numeric_limits<int>::max())
+            return std::numeric_limits<int>::max();
+        else if (m_value < std::numeric_limits<int>::min())
+            return std::numeric_limits<int>::min();
+        return m_value;
+    }
+
+    std::vector<unsigned char> getvch() const
+    {
+        return serialize(m_value);
+    }
+
+    static std::vector<unsigned char> serialize(const int64_t& value)
+    {
+        if(value == 0)
+            return std::vector<unsigned char>();
+
+        std::vector<unsigned char> result;
+        const bool neg = value < 0;
+        uint64_t absvalue = neg ? -value : value;
+
+        while(absvalue)
+        {
+            result.push_back(absvalue & 0xff);
+            absvalue >>= 8;
+        }
+
+
+//    - If the most significant byte is >= 0x80 and the value is positive, push a
+//    new zero-byte to make the significant byte < 0x80 again.
+
+//    - If the most significant byte is >= 0x80 and the value is negative, push a
+//    new 0x80 byte that will be popped off when converting to an integral.
+
+//    - If the most significant byte is < 0x80 and the value is negative, add
+//    0x80 to it, since it will be subtracted and interpreted as a negative when
+//    converting to an integral.
+
+        if (result.back() & 0x80)
+            result.push_back(neg ? 0x80 : 0);
+        else if (neg)
+            result.back() |= 0x80;
+
+        return result;
+    }
+
+    static const size_t nMaxNumSize = 4;
+
+private:
+    static int64_t set_vch(const std::vector<unsigned char>& vch)
+    {
+      if (vch.empty())
+          return 0;
+
+      int64_t result = 0;
+      for (size_t i = 0; i != vch.size(); ++i)
+          result |= static_cast<int64_t>(vch[i]) << 8*i;
+
+      // If the input vector's most significant byte is 0x80, remove it from
+      // the result's msb and return a negative.
+      if (vch.back() & 0x80)
+          return -(result & ~(0x80 << (8 * (vch.size() - 1))));
+
+      return result;
+    }
+
+    int64_t m_value;
+};
+
 /** Signature hash types/flags */
 enum
 {
@@ -225,7 +373,7 @@ const char* GetOpName(opcodetype opcode);
 inline std::string ValueString(const std::vector<unsigned char>& vch)
 {
     if (vch.size() <= 4)
-        return strprintf("%d", CBigNum(vch).getint());
+        return strprintf("%d", CScriptNum(vch).getint());
     else
         return HexStr(vch);
 }
@@ -261,26 +409,10 @@ protected:
         }
         else
         {
-            CBigNum bn(n);
-            *this << bn.getvch();
+            *this << CScriptNum::serialize(n);
         }
         return *this;
     }
-
-    CScript& push_uint64(uint64_t n)
-    {
-        if (n >= 1 && n <= 16)
-        {
-            push_back(n + (OP_1 - 1));
-        }
-        else
-        {
-            CBigNum bn(n);
-            *this << bn.getvch();
-        }
-        return *this;
-    }
-
 public:
     CScript() { }
     CScript(const CScript& b) : std::vector<unsigned char>(b.begin(), b.end()) { }
@@ -303,35 +435,15 @@ public:
     }
 
 
-    //explicit CScript(char b) is not portable.  Use 'signed char' or 'unsigned char'.
-    explicit CScript(signed char b)        { operator<<(b); }
-    explicit CScript(short b)              { operator<<(b); }
-    explicit CScript(int b)                { operator<<(b); }
-    explicit CScript(long b)               { operator<<(b); }
-    explicit CScript(long long b)          { operator<<(b); }
-    explicit CScript(unsigned char b)      { operator<<(b); }
-    explicit CScript(unsigned int b)       { operator<<(b); }
-    explicit CScript(unsigned short b)     { operator<<(b); }
-    explicit CScript(unsigned long b)      { operator<<(b); }
-    explicit CScript(unsigned long long b) { operator<<(b); }
+    CScript(int64_t b)        { operator<<(b); }
 
     explicit CScript(opcodetype b)     { operator<<(b); }
     explicit CScript(const uint256& b) { operator<<(b); }
-    explicit CScript(const CBigNum& b) { operator<<(b); }
+    explicit CScript(const CScriptNum& b) { operator<<(b); }
     explicit CScript(const std::vector<unsigned char>& b) { operator<<(b); }
 
 
-    //CScript& operator<<(char b) is not portable.  Use 'signed char' or 'unsigned char'.
-    CScript& operator<<(signed char b)        { return push_int64(b); }
-    CScript& operator<<(short b)              { return push_int64(b); }
-    CScript& operator<<(int b)                { return push_int64(b); }
-    CScript& operator<<(long b)               { return push_int64(b); }
-    CScript& operator<<(long long b)          { return push_int64(b); }
-    CScript& operator<<(unsigned char b)      { return push_uint64(b); }
-    CScript& operator<<(unsigned int b)       { return push_uint64(b); }
-    CScript& operator<<(unsigned short b)     { return push_uint64(b); }
-    CScript& operator<<(unsigned long b)      { return push_uint64(b); }
-    CScript& operator<<(unsigned long long b) { return push_uint64(b); }
+    CScript& operator<<(int64_t b) { return push_int64(b); }
 
     CScript& operator<<(opcodetype opcode)
     {
@@ -363,7 +475,7 @@ public:
         return *this;
     }
 
-    CScript& operator<<(const CBigNum& b)
+    CScript& operator<<(const CScriptNum& b)
     {
         *this << b.getvch();
         return *this;