From 9245b692020ec6a6a4ba895d333e1a056df7dc82 Mon Sep 17 00:00:00 2001
From: Daniel Larimer <dlarimer@gmail.com>
Date: Sat, 8 Sep 2012 15:05:47 -0400
Subject: [PATCH] adding bigint

---
 include/fc/bigint.hpp | 42 ++++++++++++++++++++++
 src/bigint.cpp        | 84 +++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 126 insertions(+)
 create mode 100644 include/fc/bigint.hpp
 create mode 100644 src/bigint.cpp

diff --git a/include/fc/bigint.hpp b/include/fc/bigint.hpp
new file mode 100644
index 0000000..7c68f1d
--- /dev/null
+++ b/include/fc/bigint.hpp
@@ -0,0 +1,42 @@
+#ifndef _FC_BIGINT_HPP
+#define _FC_BIGINT_HPP
+#include <stdint.h>
+#include <fc/string.hpp>
+
+struct bignum_st;
+typedef bignum_st BIGNUM;
+
+namespace fc {
+  class bigint {
+    public:
+      bigint( const char* bige, uint32_t l );
+      bigint( unsigned long i = 0 );
+      bigint( const bigint& c );
+      bigint( bigint&& c );
+      ~bigint();
+
+      bool    is_negative()const;
+      int64_t to_int64()const;
+
+      int64_t log2()const;
+      bool operator < ( const bigint& c )const;
+      bool operator > ( const bigint& c )const;
+      bool operator >= ( const bigint& c )const;
+      bool operator == ( const bigint& c )const;
+
+      bigint operator + ( const bigint& a )const;
+      bigint operator * ( const bigint& a )const;
+      bigint operator / ( const bigint& a )const; 
+      bigint operator - ( const bigint& a )const;
+
+      bigint& operator = ( const bigint& a );
+      bigint& operator = ( bigint&& a );
+
+      operator fc::string()const;
+
+    private:
+      BIGNUM* n;
+  };
+} // namespace fc
+
+#endif
diff --git a/src/bigint.cpp b/src/bigint.cpp
new file mode 100644
index 0000000..76b8864
--- /dev/null
+++ b/src/bigint.cpp
@@ -0,0 +1,84 @@
+#include <fc/bigint.hpp>
+#include <fc/utility.hpp>
+#include <openssl/bn.h>
+
+namespace fc {
+      bigint::bigint( const char* bige, uint32_t l ) {
+        n = BN_bin2bn( (const unsigned char*)bige, l, NULL );
+      }
+
+      bigint::bigint( unsigned long i )
+      :n(BN_new()) {
+        BN_set_word( n, i );
+      }
+
+      bigint::bigint( const bigint& c ) {
+        n = BN_dup( c.n );
+      }
+
+      bigint::bigint( bigint&& b ) {
+        n = b.n;
+        b.n = 0;
+      }
+
+      bigint::~bigint() {
+        if(n!=0) BN_free(n);
+      }
+
+      bool bigint::is_negative()const { return BN_is_negative(n); }
+      int64_t bigint::to_int64()const { return BN_get_word(n); }
+
+      int64_t bigint::log2()const { return BN_num_bits(n); }
+      bool bigint::operator < ( const bigint& c )const {
+        return BN_cmp( n, c.n ) < 0;
+      }
+      bool bigint::operator > ( const bigint& c )const {
+        return BN_cmp( n, c.n ) > 0;
+      }
+      bool bigint::operator >= ( const bigint& c )const {
+        return BN_cmp( n, c.n ) >= 0;
+      }
+      bool bigint::operator == ( const bigint& c )const {
+        return BN_cmp( n, c.n ) == 0;
+      }
+
+      bigint bigint::operator + ( const bigint& a )const {
+        bigint tmp(*this);
+        BN_add( tmp.n, n, a.n );
+        return tmp;
+      }
+      bigint bigint::operator * ( const bigint& a )const {
+        BN_CTX* ctx = BN_CTX_new();
+        bigint tmp(*this);
+        BN_mul( tmp.n, n, a.n, ctx );
+        BN_CTX_free(ctx);
+        return tmp;
+      }
+      bigint bigint::operator / ( const bigint& a ) const {
+        BN_CTX* ctx = BN_CTX_new();
+        bigint tmp(*this);
+        BN_div( tmp.n, NULL, n, a.n, ctx );
+        BN_CTX_free(ctx);
+        return tmp;
+      }
+      bigint bigint::operator - ( const bigint& a )const {
+        bigint tmp(*this);
+        BN_sub( tmp.n, n, a.n );
+        return tmp;
+      }
+
+
+      bigint& bigint::operator = ( bigint&& a ) {
+        fc::swap( a.n, n );
+        return *this;
+      }
+      bigint& bigint::operator = ( const bigint& a ) {
+        if( &a == this ) 
+          return *this;
+        BN_copy( n, a.n );
+        return *this;
+      }
+      bigint::operator fc::string()const {
+        return BN_bn2dec(n);
+      }
+} // namespace fc