replaces cypher with cipher

1 files changed, 144 insertions, 0 deletions

diff --git a/cipher.cpp b/cipher.cpp
new file mode 100644
index 0000000..d68204c
--- /dev/null
+++ b/cipher.cpp
@@ -0,0 +1,144 @@
+/*
+ *  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 <stdexcept>
+#include <iostream>
+#include <string>
+#include <cstdio>
+#include <gcrypt.h>
+
+#include "cipher.h"
+#include "mpi.h"
+#include "log.h"
+
+void Cipher::encrypt(const PlainPacket & in,EncryptedPacket & out, seq_nr_t seq_nr, sender_id_t sender_id)
+{
+	cipher(out.payload_, in.complete_payload_ , in.complete_payload_length_, seq_nr, sender_id);
+	out.setSenderId(sender_id);
+	out.setSeqNr(seq_nr);
+	out.setPayloadLength(in.complete_payload_length_);
+}
+
+void Cipher::decrypt(const EncryptedPacket & in,PlainPacket & out)
+{
+	cipher(out.complete_payload_, in.payload_ , in.payload_length_, in.getSeqNr(), in.getSenderId());
+	out.setCompletePayloadLength(in.payload_length_);
+}
+
+
+
+//****** NullCipher ******
+
+void NullCipher::cipher(u_int8_t * out, u_int8_t * in, u_int32_t length, seq_nr_t seq_nr, sender_id_t sender_id)
+{
+	std::memcpy(out, in, length );
+}
+
+
+
+//****** AesIcmCipher ****** 
+
+AesIcmCipher::AesIcmCipher() : salt_(Buffer(14))   // Q@NINE 14??????
+{
+  gcry_error_t err;
+
+      // TODO: hardcoded keysize!!!!!
+  err = gcry_cipher_open( &cipher_, GCRY_CIPHER_AES128, GCRY_CIPHER_MODE_CTR, 0 );
+  if( err )
+    cLog.msg(Log::PRIO_CRIT) << "AesIcmCipher::AesIcmCipher: Failed to open cipher";
+}
+
+
+AesIcmCipher::~AesIcmCipher()
+{
+  gcry_cipher_close( cipher_ );
+  cLog.msg(Log::PRIO_DEBUG) << "AesIcmCipher::~AesIcmCipher: closed cipher";
+}
+
+
+void AesIcmCipher::setKey(Buffer key)
+{
+  gcry_error_t err;
+
+  err = gcry_cipher_setkey( cipher_, key.getBuf(), key.getLength() );
+  if( err )
+    cLog.msg(Log::PRIO_ERR) << "AesIcmCipher::setKey: Failed to set cipher key: " << gpg_strerror( err );
+}
+
+void AesIcmCipher::setSalt(Buffer salt)
+{
+  salt_ = salt;
+}
+
+void AesIcmCipher::cipher(u_int8_t *  out, u_int8_t * in, u_int32_t length, seq_nr_t seq_nr, sender_id_t sender_id)
+{
+  gcry_error_t err;
+
+  // set the IV
+  //==========================================================================
+  //  //  where the 128-bit integer value IV SHALL be defined by the SSRC, the
+  //  //  SRTP packet index i, and the SRTP session salting key k_s, as below.
+  //  //
+  //  //  IV = (k_s * 2^16) XOR (SSRC * 2^64) XOR (i * 2^16)
+  //  //  sizeof(k_s) = 112 bit, random
+
+  Mpi iv(128);  // TODO: hardcoded size
+  Mpi salt = Mpi(salt_.getBuf(), salt_.getLength());
+  Mpi sid = sender_id;
+  Mpi seq = seq_nr;
+
+  iv = salt.mul2exp(16) ^ sid.mul2exp(64) ^ seq.mul2exp(16); // TODO: hardcoded size
+
+  u_int8_t *iv_buf = iv.getNewBuf(16);  // TODO: hardcoded size
+
+      // Q@NINE -> CTR Mode -> gcry_cipher_setctr() ????
+
+  err = gcry_cipher_setiv( cipher_, iv_buf, 16 );  // TODO: hardcoded size
+  delete[] iv_buf;
+  if( err ) {
+    cLog.msg(Log::PRIO_ERR) << "AesIcmCipher: Failed to set cipher IV: " << gpg_strerror( err );
+    return;
+  }
+
+      // Q@NINE -> reset clears IV ????
+  
+  err = gcry_cipher_reset( cipher_ );
+  if( err ) {
+    cLog.msg(Log::PRIO_ERR) << "AesIcmCipher: Failed to reset cipher: " << gpg_strerror( err );
+    return;
+  }
+
+  err = gcry_cipher_encrypt( cipher_, out, length, in, length );
+  if( err ) {
+    cLog.msg(Log::PRIO_ERR) << "AesIcmCipher: Failed to generate cipher bitstream: " << gpg_strerror( err );
+    return;
+  }
+}
+