Merge pull request #3965

b1fdd54 script: Add test for CScriptNum (Cory Fields)
90320d6 script: add additional script tests (Cory Fields)
05e3ecf script: remove bignum dependency (Cory Fields)
4f497cd script: switch outside users to CScriptNum (Cory Fields)
27bff74 script: switch to CScriptNum usage for scripts (Cory Fields)
48d8eb1 script: add CScriptNum class (Cory Fields)

8 files changed, 387 insertions, 73 deletions

diff --git a/src/chainparams.cpp b/src/chainparams.cpp
index b52774ee20..eb56800b92 100644
--- a/src/chainparams.cpp
+++ b/src/chainparams.cpp
@@ -125,7 +125,7 @@ public:
         CTransaction txNew;
         txNew.vin.resize(1);
         txNew.vout.resize(1);
-        txNew.vin[0].scriptSig = CScript() << 486604799 << CBigNum(4) << vector<unsigned char>((const unsigned char*)pszTimestamp, (const unsigned char*)pszTimestamp + strlen(pszTimestamp));
+        txNew.vin[0].scriptSig = CScript() << 486604799 << CScriptNum(4) << vector<unsigned char>((const unsigned char*)pszTimestamp, (const unsigned char*)pszTimestamp + strlen(pszTimestamp));
         txNew.vout[0].nValue = 50 * COIN;
         txNew.vout[0].scriptPubKey = CScript() << ParseHex("04678afdb0fe5548271967f1a67130b7105cd6a828e03909a67962e0ea1f61deb649f6bc3f4cef38c4f35504e51ec112de5c384df7ba0b8d578a4c702b6bf11d5f") << OP_CHECKSIG;
         genesis.vtx.push_back(txNew);
diff --git a/src/miner.cpp b/src/miner.cpp
index 3351908e65..f21ee0c3a8 100644
--- a/src/miner.cpp
+++ b/src/miner.cpp
@@ -355,7 +355,7 @@ void IncrementExtraNonce(CBlock* pblock, CBlockIndex* pindexPrev, unsigned int&
     }
     ++nExtraNonce;
     unsigned int nHeight = pindexPrev->nHeight+1; // Height first in coinbase required for block.version=2
-    pblock->vtx[0].vin[0].scriptSig = (CScript() << nHeight << CBigNum(nExtraNonce)) + COINBASE_FLAGS;
+    pblock->vtx[0].vin[0].scriptSig = (CScript() << nHeight << CScriptNum(nExtraNonce)) + COINBASE_FLAGS;
     assert(pblock->vtx[0].vin[0].scriptSig.size() <= 100);
 
     pblock->hashMerkleRoot = pblock->BuildMerkleTree();
diff --git a/src/script.cpp b/src/script.cpp
index 810ba16d28..81d2754453 100644
--- a/src/script.cpp
+++ b/src/script.cpp
@@ -5,7 +5,6 @@
 
 #include "script.h"
 
-#include "bignum.h"
 #include "core.h"
 #include "hash.h"
 #include "key.h"
@@ -25,22 +24,13 @@ typedef vector<unsigned char> valtype;
 static const valtype vchFalse(0);
 static const valtype vchZero(0);
 static const valtype vchTrue(1, 1);
-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 = 4;
+static const CScriptNum bnZero(0);
+static const CScriptNum bnOne(1);
+static const CScriptNum bnFalse(0);
+static const CScriptNum bnTrue(1);
 
 bool CheckSig(vector<unsigned char> vchSig, const vector<unsigned char> &vchPubKey, const CScript &scriptCode, const CTransaction& txTo, unsigned int nIn, int nHashType, int flags);
 
-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)
 {
     for (unsigned int i = 0; i < vch.size(); i++)
@@ -306,7 +296,6 @@ bool IsCanonicalSignature(const valtype &vchSig, unsigned int flags) {
 
 bool EvalScript(vector<vector<unsigned char> >& stack, const CScript& script, const CTransaction& txTo, unsigned int nIn, unsigned int flags, int nHashType)
 {
-    CAutoBN_CTX pctx;
     CScript::const_iterator pc = script.begin();
     CScript::const_iterator pend = script.end();
     CScript::const_iterator pbegincodehash = script.begin();
@@ -380,7 +369,7 @@ bool EvalScript(vector<vector<unsigned char> >& stack, const CScript& script, co
                 case OP_16:
                 {
                     // ( -- value)
-                    CBigNum bn((int)opcode - (int)(OP_1 - 1));
+                    CScriptNum bn((int)opcode - (int)(OP_1 - 1));
                     stack.push_back(bn.getvch());
                 }
                 break;
@@ -556,7 +545,7 @@ bool EvalScript(vector<vector<unsigned char> >& stack, const CScript& script, co
                 case OP_DEPTH:
                 {
                     // -- stacksize
-                    CBigNum bn(stack.size());
+                    CScriptNum bn(stack.size());
                     stack.push_back(bn.getvch());
                 }
                 break;
@@ -606,7 +595,7 @@ 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 = CastToBigNum(stacktop(-1)).getint();
+                    int n = CScriptNum(stacktop(-1)).getint();
                     popstack(stack);
                     if (n < 0 || n >= (int)stack.size())
                         return false;
@@ -654,7 +643,7 @@ bool EvalScript(vector<vector<unsigned char> >& stack, const CScript& script, co
                     // (in -- in size)
                     if (stack.size() < 1)
                         return false;
-                    CBigNum bn(stacktop(-1).size());
+                    CScriptNum bn(stacktop(-1).size());
                     stack.push_back(bn.getvch());
                 }
                 break;
@@ -705,7 +694,7 @@ bool EvalScript(vector<vector<unsigned char> >& stack, const CScript& script, co
                     // (in -- out)
                     if (stack.size() < 1)
                         return false;
-                    CBigNum bn = CastToBigNum(stacktop(-1));
+                    CScriptNum bn(stacktop(-1));
                     switch (opcode)
                     {
                     case OP_1ADD:       bn += bnOne; break;
@@ -738,9 +727,9 @@ bool EvalScript(vector<vector<unsigned char> >& stack, const CScript& script, co
                     // (x1 x2 -- out)
                     if (stack.size() < 2)
                         return false;
-                    CBigNum bn1 = CastToBigNum(stacktop(-2));
-                    CBigNum bn2 = CastToBigNum(stacktop(-1));
-                    CBigNum bn;
+                    CScriptNum bn1(stacktop(-2));
+                    CScriptNum bn2(stacktop(-1));
+                    CScriptNum bn(0);
                     switch (opcode)
                     {
                     case OP_ADD:
@@ -783,9 +772,9 @@ bool EvalScript(vector<vector<unsigned char> >& stack, const CScript& script, co
                     // (x min max -- out)
                     if (stack.size() < 3)
                         return false;
-                    CBigNum bn1 = CastToBigNum(stacktop(-3));
-                    CBigNum bn2 = CastToBigNum(stacktop(-2));
-                    CBigNum bn3 = CastToBigNum(stacktop(-1));
+                    CScriptNum bn1(stacktop(-3));
+                    CScriptNum bn2(stacktop(-2));
+                    CScriptNum bn3(stacktop(-1));
                     bool fValue = (bn2 <= bn1 && bn1 < bn3);
                     popstack(stack);
                     popstack(stack);
@@ -882,7 +871,7 @@ bool EvalScript(vector<vector<unsigned char> >& stack, const CScript& script, co
                     if ((int)stack.size() < i)
                         return false;
 
-                    int nKeysCount = CastToBigNum(stacktop(-i)).getint();
+                    int nKeysCount = CScriptNum(stacktop(-i)).getint();
                     if (nKeysCount < 0 || nKeysCount > 20)
                         return false;
                     nOpCount += nKeysCount;
@@ -893,7 +882,7 @@ bool EvalScript(vector<vector<unsigned char> >& stack, const CScript& script, co
                     if ((int)stack.size() < i)
                         return false;
 
-                    int nSigsCount = CastToBigNum(stacktop(-i)).getint();
+                    int nSigsCount = CScriptNum(stacktop(-i)).getint();
                     if (nSigsCount < 0 || nSigsCount > nKeysCount)
                         return false;
                     int isig = ++i;
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;
diff --git a/src/test/Makefile.am b/src/test/Makefile.am
index b375ba1306..e12f4904f1 100644
--- a/src/test/Makefile.am
+++ b/src/test/Makefile.am
@@ -61,6 +61,7 @@ test_bitcoin_SOURCES = \
   transaction_tests.cpp \
   uint256_tests.cpp \
   util_tests.cpp \
+  scriptnum_tests.cpp \
   sighash_tests.cpp \
   $(JSON_TEST_FILES) $(RAW_TEST_FILES)
 
diff --git a/src/test/data/script_invalid.json b/src/test/data/script_invalid.json
index c2824cb6f7..d623e974b8 100644
--- a/src/test/data/script_invalid.json
+++ b/src/test/data/script_invalid.json
@@ -267,7 +267,10 @@
 ["1","0xba", "0xba == OP_NOP10 + 1"],
 
 ["2147483648", "1ADD 1", "We cannot do math on 5-byte integers"],
+["2147483648", "NEGATE 1", "We cannot do math on 5-byte integers"],
 ["-2147483648", "1ADD 1", "Because we use a sign bit, -2147483648 is also 5 bytes"],
+["2147483647", "1ADD 1SUB 1", "We cannot do math on 5-byte integers, even if the result is 4-bytes"],
+["2147483648", "1SUB 1", "We cannot do math on 5-byte integers, even if the result is 4-bytes"],
 
 ["1", "1 ENDIF", "ENDIF without IF"],
 ["1", "IF 1", "IF without ENDIF"],
diff --git a/src/test/data/script_valid.json b/src/test/data/script_valid.json
index 162e5c3abd..7546a3b1fe 100644
--- a/src/test/data/script_valid.json
+++ b/src/test/data/script_valid.json
@@ -109,6 +109,9 @@
 ["8388608", "SIZE 4 EQUAL"],
 ["2147483647", "SIZE 4 EQUAL"],
 ["2147483648", "SIZE 5 EQUAL"],
+["549755813887", "SIZE 5 EQUAL"],
+["549755813888", "SIZE 6 EQUAL"],
+["9223372036854775807", "SIZE 8 EQUAL"],
 ["-1", "SIZE 1 EQUAL"],
 ["-127", "SIZE 1 EQUAL"],
 ["-128", "SIZE 2 EQUAL"],
@@ -118,6 +121,9 @@
 ["-8388608", "SIZE 4 EQUAL"],
 ["-2147483647", "SIZE 4 EQUAL"],
 ["-2147483648", "SIZE 5 EQUAL"],
+["-549755813887", "SIZE 5 EQUAL"],
+["-549755813888", "SIZE 6 EQUAL"],
+["-9223372036854775807", "SIZE 8 EQUAL"],
 ["'abcdefghijklmnopqrstuvwxyz'", "SIZE 26 EQUAL"],
 
 
@@ -318,6 +324,9 @@
 ["8388608", "0x04 0x00008000 EQUAL"],
 ["2147483647", "0x04 0xFFFFFF7F EQUAL"],
 ["2147483648", "0x05 0x0000008000 EQUAL"],
+["549755813887", "0x05 0xFFFFFFFF7F EQUAL"],
+["549755813888", "0x06 0xFFFFFFFF7F EQUAL"],
+["9223372036854775807", "0x08 0xFFFFFFFFFFFFFF7F EQUAL"],
 ["-1", "0x01 0x81 EQUAL", "Numbers are little-endian with the MSB being a sign bit"],
 ["-127", "0x01 0xFF EQUAL"],
 ["-128", "0x02 0x8080 EQUAL"],
@@ -327,6 +336,10 @@
 ["-8388608", "0x04 0x00008080 EQUAL"],
 ["-2147483647", "0x04 0xFFFFFFFF EQUAL"],
 ["-2147483648", "0x05 0x0000008080 EQUAL"],
+["-4294967295", "0x05 0xFFFFFFFF80 EQUAL"],
+["-549755813887", "0x05 0xFFFFFFFFFF EQUAL"],
+["-549755813888", "0x06 0x000000008080 EQUAL"],
+["-9223372036854775807", "0x08 0xFFFFFFFFFFFFFFFF EQUAL"],
 
 ["2147483647", "1ADD 2147483648 EQUAL", "We can do math on 4-byte integers, and compare 5-byte ones"],
 ["2147483647", "1ADD 1"],
diff --git a/src/test/scriptnum_tests.cpp b/src/test/scriptnum_tests.cpp
new file mode 100644
index 0000000000..cd194cc4d9
--- /dev/null
+++ b/src/test/scriptnum_tests.cpp
@@ -0,0 +1,196 @@
+// Copyright (c) 2012-2014 The Bitcoin Core developers
+// Distributed under the MIT/X11 software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include "bignum.h"
+#include "script.h"
+#include <boost/test/unit_test.hpp>
+#include <limits.h>
+#include <stdint.h>
+BOOST_AUTO_TEST_SUITE(scriptnum_tests)
+
+static const int64_t values[] = \
+{ 0, 1, CHAR_MIN, CHAR_MAX, UCHAR_MAX, SHRT_MIN, USHRT_MAX, INT_MIN, INT_MAX, UINT_MAX, LONG_MIN, LONG_MAX };
+static const int64_t offsets[] = { 1, 0x79, 0x80, 0x81, 0xFF, 0x7FFF, 0x8000, 0xFFFF, 0x10000};
+
+static bool verify(const CBigNum& bignum, const CScriptNum& scriptnum)
+{
+    return bignum.getvch() == scriptnum.getvch() && bignum.getint() == scriptnum.getint();
+}
+
+static void CheckCreateVch(const int64_t& num)
+{
+    CBigNum bignum(num);
+    CScriptNum scriptnum(num);
+    BOOST_CHECK(verify(bignum, scriptnum));
+
+    CBigNum bignum2(bignum.getvch());
+    CScriptNum scriptnum2(scriptnum.getvch());
+    BOOST_CHECK(verify(bignum2, scriptnum2));
+
+    CBigNum bignum3(scriptnum2.getvch());
+    CScriptNum scriptnum3(bignum2.getvch());
+    BOOST_CHECK(verify(bignum3, scriptnum3));
+}
+
+static void CheckCreateInt(const int64_t& num)
+{
+    CBigNum bignum(num);
+    CScriptNum scriptnum(num);
+    BOOST_CHECK(verify(bignum, scriptnum));
+    BOOST_CHECK(verify(bignum.getint(), CScriptNum(scriptnum.getint())));
+    BOOST_CHECK(verify(scriptnum.getint(), CScriptNum(bignum.getint())));
+    BOOST_CHECK(verify(CBigNum(scriptnum.getint()).getint(), CScriptNum(CScriptNum(bignum.getint()).getint())));
+}
+
+
+static void CheckAdd(const int64_t& num1, const int64_t& num2)
+{
+    const CBigNum bignum1(num1);
+    const CBigNum bignum2(num2);
+    const CScriptNum scriptnum1(num1);
+    const CScriptNum scriptnum2(num2);
+    CBigNum bignum3(num1);
+    CBigNum bignum4(num1);
+    CScriptNum scriptnum3(num1);
+    CScriptNum scriptnum4(num1);
+
+    // int64_t overflow is undefined.
+    bool invalid = (((num2 > 0) && (num1 > (std::numeric_limits<int64_t>::max() - num2))) ||
+                    ((num2 < 0) && (num1 < (std::numeric_limits<int64_t>::min() - num2))));
+    if (!invalid)
+    {
+        BOOST_CHECK(verify(bignum1 + bignum2, scriptnum1 + scriptnum2));
+        BOOST_CHECK(verify(bignum1 + bignum2, scriptnum1 + num2));
+        BOOST_CHECK(verify(bignum1 + bignum2, scriptnum2 + num1));
+    }
+}
+
+static void CheckNegate(const int64_t& num)
+{
+    const CBigNum bignum(num);
+    const CScriptNum scriptnum(num);
+
+    // -INT64_MIN is undefined
+    if (num != std::numeric_limits<int64_t>::min())
+        BOOST_CHECK(verify(-bignum, -scriptnum));
+}
+
+static void CheckSubtract(const int64_t& num1, const int64_t& num2)
+{
+    const CBigNum bignum1(num1);
+    const CBigNum bignum2(num2);
+    const CScriptNum scriptnum1(num1);
+    const CScriptNum scriptnum2(num2);
+    bool invalid = false;
+
+    // int64_t overflow is undefined.
+    invalid = ((num2 > 0 && num1 < std::numeric_limits<int64_t>::min() + num2) ||
+               (num2 < 0 && num1 > std::numeric_limits<int64_t>::max() + num2));
+    if (!invalid)
+    {
+        BOOST_CHECK(verify(bignum1 - bignum2, scriptnum1 - scriptnum2));
+        BOOST_CHECK(verify(bignum1 - bignum2, scriptnum1 - num2));
+    }
+
+    invalid = ((num1 > 0 && num2 < std::numeric_limits<int64_t>::min() + num1) ||
+               (num1 < 0 && num2 > std::numeric_limits<int64_t>::max() + num1));
+    if (!invalid)
+    {
+        BOOST_CHECK(verify(bignum2 - bignum1, scriptnum2 - scriptnum1));
+        BOOST_CHECK(verify(bignum2 - bignum1, scriptnum2 - num1));
+    }
+}
+
+static void CheckCompare(const int64_t& num1, const int64_t& num2)
+{
+    const CBigNum bignum1(num1);
+    const CBigNum bignum2(num2);
+    const CScriptNum scriptnum1(num1);
+    const CScriptNum scriptnum2(num2);
+
+    BOOST_CHECK((bignum1 == bignum1) == (scriptnum1 == scriptnum1));
+    BOOST_CHECK((bignum1 != bignum1) ==  (scriptnum1 != scriptnum1));
+    BOOST_CHECK((bignum1 < bignum1) ==  (scriptnum1 < scriptnum1));
+    BOOST_CHECK((bignum1 > bignum1) ==  (scriptnum1 > scriptnum1));
+    BOOST_CHECK((bignum1 >= bignum1) ==  (scriptnum1 >= scriptnum1));
+    BOOST_CHECK((bignum1 <= bignum1) ==  (scriptnum1 <= scriptnum1));
+
+    BOOST_CHECK((bignum1 == bignum1) == (scriptnum1 == num1));
+    BOOST_CHECK((bignum1 != bignum1) ==  (scriptnum1 != num1));
+    BOOST_CHECK((bignum1 < bignum1) ==  (scriptnum1 < num1));
+    BOOST_CHECK((bignum1 > bignum1) ==  (scriptnum1 > num1));
+    BOOST_CHECK((bignum1 >= bignum1) ==  (scriptnum1 >= num1));
+    BOOST_CHECK((bignum1 <= bignum1) ==  (scriptnum1 <= num1));
+
+    BOOST_CHECK((bignum1 == bignum2) ==  (scriptnum1 == scriptnum2));
+    BOOST_CHECK((bignum1 != bignum2) ==  (scriptnum1 != scriptnum2));
+    BOOST_CHECK((bignum1 < bignum2) ==  (scriptnum1 < scriptnum2));
+    BOOST_CHECK((bignum1 > bignum2) ==  (scriptnum1 > scriptnum2));
+    BOOST_CHECK((bignum1 >= bignum2) ==  (scriptnum1 >= scriptnum2));
+    BOOST_CHECK((bignum1 <= bignum2) ==  (scriptnum1 <= scriptnum2));
+
+    BOOST_CHECK((bignum1 == bignum2) ==  (scriptnum1 == num2));
+    BOOST_CHECK((bignum1 != bignum2) ==  (scriptnum1 != num2));
+    BOOST_CHECK((bignum1 < bignum2) ==  (scriptnum1 < num2));
+    BOOST_CHECK((bignum1 > bignum2) ==  (scriptnum1 > num2));
+    BOOST_CHECK((bignum1 >= bignum2) ==  (scriptnum1 >= num2));
+    BOOST_CHECK((bignum1 <= bignum2) ==  (scriptnum1 <= num2));
+}
+
+static void RunCreate(const int64_t& num)
+{
+    CheckCreateInt(num);
+    CScriptNum scriptnum(num);
+    if (scriptnum.getvch().size() <= CScriptNum::nMaxNumSize)
+        CheckCreateVch(num);
+    else
+    {
+        BOOST_CHECK_THROW (CheckCreateVch(num), scriptnum_error);
+    }
+}
+
+static void RunOperators(const int64_t& num1, const int64_t& num2)
+{
+    CheckAdd(num1, num2);
+    CheckSubtract(num1, num2);
+    CheckNegate(num1);
+    CheckCompare(num1, num2);
+}
+
+BOOST_AUTO_TEST_CASE(creation)
+{
+    for(size_t i = 0; i < sizeof(values) / sizeof(values[0]); ++i)
+    {
+        for(size_t j = 0; j < sizeof(offsets) / sizeof(offsets[0]); ++j)
+        {
+            RunCreate(values[i]);
+            RunCreate(values[i] + offsets[j]);
+            RunCreate(values[i] - offsets[j]);
+        }
+    }
+}
+
+BOOST_AUTO_TEST_CASE(operators)
+{
+    for(size_t i = 0; i < sizeof(values) / sizeof(values[0]); ++i)
+    {
+        for(size_t j = 0; j < sizeof(offsets) / sizeof(offsets[0]); ++j)
+        {
+            RunOperators(values[i], values[i]);
+            RunOperators(values[i], -values[i]);
+            RunOperators(values[i], values[j]);
+            RunOperators(values[i], -values[j]);
+            RunOperators(values[i] + values[j], values[j]);
+            RunOperators(values[i] + values[j], -values[j]);
+            RunOperators(values[i] - values[j], values[j]);
+            RunOperators(values[i] - values[j], -values[j]);
+            RunOperators(values[i] + values[j], values[i] + values[j]);
+            RunOperators(values[i] + values[j], values[i] - values[j]);
+            RunOperators(values[i] - values[j], values[i] + values[j]);
+            RunOperators(values[i] - values[j], values[i] - values[j]);
+        }
+    }
+}
+
+BOOST_AUTO_TEST_SUITE_END()