added multible precission integer class

key derivation

1 files changed, 118 insertions, 0 deletions

diff --git a/mpi.cpp b/mpi.cpp
new file mode 100644
index 0000000..510a17f
--- /dev/null
+++ b/mpi.cpp
@@ -0,0 +1,118 @@
+/*
+ *  anytun
+ *
+ *  The secure anycast tunneling protocol (satp) defines a protocol used
+ *  for communication between any combination of unicast and anycast
+ *  tunnel endpoints.  It has less protocol overhead than IPSec in Tunnel
+ *  mode and allows tunneling of every ETHER TYPE protocol (e.g.
+ *  ethernet, ip, arp ...). satp directly includes cryptography and
+ *  message authentication based on the methodes used by SRTP.  It is
+ *  intended to deliver a generic, scaleable and secure solution for
+ *  tunneling and relaying of packets of any protocol.
+ *
+ *
+ *  Copyright (C) 2007 anytun.org <satp@wirdorange.org>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2
+ *  as published by the Free Software Foundation.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program (see the file COPYING included with this
+ *  distribution); if not, write to the Free Software Foundation, Inc.,
+ *  59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include "mpi.h"
+
+#include "datatypes.h"
+#include "cypher.h"
+
+#include <stdexcept>
+#include <gcrypt.h>
+
+
+Mpi::Mpi() : val_(NULL)
+{
+}
+
+Mpi::Mpi(u_int8_t length)
+{
+  val_ = gcry_mpi_new(length);
+}
+
+Mpi::Mpi(const Mpi &src)
+{
+  val_ = gcry_mpi_copy(src.val_);
+}
+
+Mpi::Mpi(const u_int8_t * src, u_int32_t len)
+{
+  gcry_mpi_scan( &val_, GCRYMPI_FMT_STD, src, len, NULL );
+}
+void Mpi::operator=(const Mpi &src)
+{
+  val_ = gcry_mpi_copy(src.val_);
+}
+
+void Mpi::operator=(const long unsigned int src)
+{
+  gcry_mpi_set_ui(val_, src);
+}
+
+Mpi Mpi::operator+(const Mpi &b) const
+{
+  Mpi res;
+  gcry_mpi_add(res.val_, val_, b.val_);
+  return res;
+}
+
+Mpi Mpi::operator^(const Mpi &b) const
+{
+  u_int32_t len = 0;
+
+  Mpi res(gcry_mpi_get_nbits(val_));
+
+  if(gcry_mpi_get_nbits(val_) != gcry_mpi_get_nbits(b.val_))
+    throw std::length_error("mpi::operator^ const");
+
+  len = gcry_mpi_get_nbits(val_);
+
+  for(u_int32_t i=0; i<len; i++) {
+    if(gcry_mpi_test_bit(val_, i) ^ gcry_mpi_test_bit(b.val_, i))
+      gcry_mpi_set_bit(res.val_, i);
+  }
+  return res;
+}
+
+void Mpi::rShift(u_int8_t n)
+{
+  gcry_mpi_rshift(val_, val_, n);
+}
+
+Buffer Mpi::getBuf() const
+{
+  u_int32_t len = 0, written = 0;
+  len = gcry_mpi_get_nbits( val_ );
+
+  Buffer res(static_cast<u_int32_t>(len/8)+1);
+
+  gcry_mpi_print( GCRYMPI_FMT_STD, res, len, &written, val_ );
+  return res;
+}
+
+u_int32_t Mpi::getLen() const
+{
+  return gcry_mpi_get_nbits( val_ );
+}
+
+Mpi::~Mpi()
+{
+  gcry_mpi_release( val_ );
+}
+