1 files changed, 179 insertions, 0 deletions
diff --git a/src/test/bignum.h b/src/test/bignum.h
new file mode 100644
index 0000000000..b57800f372
--- /dev/null
+++ b/src/test/bignum.h
@@ -0,0 +1,179 @@
+// Copyright (c) 2009-2010 Satoshi Nakamoto
+// Copyright (c) 2009-2013 The Bitcoin developers
+// Distributed under the MIT/X11 software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef BITCOIN_BIGNUM_H
+#define BITCOIN_BIGNUM_H
+
+#include <algorithm>
+#include <limits>
+#include <stdexcept>
+#include <stdint.h>
+#include <vector>
+
+#include <openssl/bn.h>
+
+class bignum_error : public std::runtime_error
+{
+public:
+    explicit bignum_error(const std::string& str) : std::runtime_error(str) {}
+};
+
+
+/** C++ wrapper for BIGNUM (OpenSSL bignum) */
+class CBigNum : public BIGNUM
+{
+public:
+    CBigNum()
+    {
+        BN_init(this);
+    }
+
+    CBigNum(const CBigNum& b)
+    {
+        BN_init(this);
+        if (!BN_copy(this, &b))
+        {
+            BN_clear_free(this);
+            throw bignum_error("CBigNum::CBigNum(const CBigNum&) : BN_copy failed");
+        }
+    }
+
+    CBigNum& operator=(const CBigNum& b)
+    {
+        if (!BN_copy(this, &b))
+            throw bignum_error("CBigNum::operator= : BN_copy failed");
+        return (*this);
+    }
+
+    ~CBigNum()
+    {
+        BN_clear_free(this);
+    }
+
+    CBigNum(long long n)          { BN_init(this); setint64(n); }
+
+    explicit CBigNum(const std::vector<unsigned char>& vch)
+    {
+        BN_init(this);
+        setvch(vch);
+    }
+
+    int getint() const
+    {
+        unsigned long n = BN_get_word(this);
+        if (!BN_is_negative(this))
+            return (n > (unsigned long)std::numeric_limits<int>::max() ? std::numeric_limits<int>::max() : n);
+        else
+            return (n > (unsigned long)std::numeric_limits<int>::max() ? std::numeric_limits<int>::min() : -(int)n);
+    }
+
+    void setint64(int64_t sn)
+    {
+        unsigned char pch[sizeof(sn) + 6];
+        unsigned char* p = pch + 4;
+        bool fNegative;
+        uint64_t n;
+
+        if (sn < (int64_t)0)
+        {
+            // Since the minimum signed integer cannot be represented as positive so long as its type is signed, 
+            // and it's not well-defined what happens if you make it unsigned before negating it,
+            // we instead increment the negative integer by 1, convert it, then increment the (now positive) unsigned integer by 1 to compensate
+            n = -(sn + 1);
+            ++n;
+            fNegative = true;
+        } else {
+            n = sn;
+            fNegative = false;
+        }
+
+        bool fLeadingZeroes = true;
+        for (int i = 0; i < 8; i++)
+        {
+            unsigned char c = (n >> 56) & 0xff;
+            n <<= 8;
+            if (fLeadingZeroes)
+            {
+                if (c == 0)
+                    continue;
+                if (c & 0x80)
+                    *p++ = (fNegative ? 0x80 : 0);
+                else if (fNegative)
+                    c |= 0x80;
+                fLeadingZeroes = false;
+            }
+            *p++ = c;
+        }
+        unsigned int nSize = p - (pch + 4);
+        pch[0] = (nSize >> 24) & 0xff;
+        pch[1] = (nSize >> 16) & 0xff;
+        pch[2] = (nSize >> 8) & 0xff;
+        pch[3] = (nSize) & 0xff;
+        BN_mpi2bn(pch, p - pch, this);
+    }
+
+    void setvch(const std::vector<unsigned char>& vch)
+    {
+        std::vector<unsigned char> vch2(vch.size() + 4);
+        unsigned int nSize = vch.size();
+        // BIGNUM's byte stream format expects 4 bytes of
+        // big endian size data info at the front
+        vch2[0] = (nSize >> 24) & 0xff;
+        vch2[1] = (nSize >> 16) & 0xff;
+        vch2[2] = (nSize >> 8) & 0xff;
+        vch2[3] = (nSize >> 0) & 0xff;
+        // swap data to big endian
+        reverse_copy(vch.begin(), vch.end(), vch2.begin() + 4);
+        BN_mpi2bn(&vch2[0], vch2.size(), this);
+    }
+
+    std::vector<unsigned char> getvch() const
+    {
+        unsigned int nSize = BN_bn2mpi(this, NULL);
+        if (nSize <= 4)
+            return std::vector<unsigned char>();
+        std::vector<unsigned char> vch(nSize);
+        BN_bn2mpi(this, &vch[0]);
+        vch.erase(vch.begin(), vch.begin() + 4);
+        reverse(vch.begin(), vch.end());
+        return vch;
+    }
+
+    friend inline const CBigNum operator-(const CBigNum& a, const CBigNum& b);
+};
+
+
+
+inline const CBigNum operator+(const CBigNum& a, const CBigNum& b)
+{
+    CBigNum r;
+    if (!BN_add(&r, &a, &b))
+        throw bignum_error("CBigNum::operator+ : BN_add failed");
+    return r;
+}
+
+inline const CBigNum operator-(const CBigNum& a, const CBigNum& b)
+{
+    CBigNum r;
+    if (!BN_sub(&r, &a, &b))
+        throw bignum_error("CBigNum::operator- : BN_sub failed");
+    return r;
+}
+
+inline const CBigNum operator-(const CBigNum& a)
+{
+    CBigNum r(a);
+    BN_set_negative(&r, !BN_is_negative(&r));
+    return r;
+}
+
+inline bool operator==(const CBigNum& a, const CBigNum& b) { return (BN_cmp(&a, &b) == 0); }
+inline bool operator!=(const CBigNum& a, const CBigNum& b) { return (BN_cmp(&a, &b) != 0); }
+inline bool operator<=(const CBigNum& a, const CBigNum& b) { return (BN_cmp(&a, &b) <= 0); }
+inline bool operator>=(const CBigNum& a, const CBigNum& b) { return (BN_cmp(&a, &b) >= 0); }
+inline bool operator<(const CBigNum& a, const CBigNum& b)  { return (BN_cmp(&a, &b) < 0); }
+inline bool operator>(const CBigNum& a, const CBigNum& b)  { return (BN_cmp(&a, &b) > 0); }
+
+#endif