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authorOthmar Gsenger <otti@anytun.org>2008-04-12 11:38:42 +0000
committerOthmar Gsenger <otti@anytun.org>2008-04-12 11:38:42 +0000
commitfffd213c8cba2135afda493d797c41c10354770e (patch)
treebb5eea1b12871d8c3fed0e687d83be3e504d11b2 /src/authAlgo.cpp
parentsvn cleanup (diff)
big svn cleanup
Diffstat (limited to 'src/authAlgo.cpp')
-rw-r--r--src/authAlgo.cpp125
1 files changed, 125 insertions, 0 deletions
diff --git a/src/authAlgo.cpp b/src/authAlgo.cpp
new file mode 100644
index 0000000..6b1c9ec
--- /dev/null
+++ b/src/authAlgo.cpp
@@ -0,0 +1,125 @@
+/*
+ * 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 "authAlgo.h"
+#include "log.h"
+#include "buffer.h"
+#include "encryptedPacket.h"
+
+#include <iostream>
+
+#include <gcrypt.h>
+
+//****** NullAuthAlgo ******
+void NullAuthAlgo::generate(EncryptedPacket& packet)
+{
+}
+
+bool NullAuthAlgo::checkTag(EncryptedPacket& packet)
+{
+ return true;
+}
+
+u_int32_t NullAuthAlgo::getMaxLength()
+{
+ return MAX_LENGTH_;
+}
+
+//****** Sha1AuthAlgo ******
+
+Sha1AuthAlgo::Sha1AuthAlgo() : ctx_(NULL)
+{
+ gcry_error_t err = gcry_md_open( &ctx_, GCRY_MD_SHA1, GCRY_MD_FLAG_HMAC );
+ if( err )
+ cLog.msg(Log::PRIO_CRIT) << "Sha1AuthAlgo::Sha1AuthAlgo: Failed to open message digest algo";
+}
+
+Sha1AuthAlgo::~Sha1AuthAlgo()
+{
+ if(ctx_)
+ gcry_md_close( ctx_ );
+}
+
+void Sha1AuthAlgo::setKey(Buffer& key)
+{
+ if(!ctx_)
+ return;
+
+ gcry_error_t err = gcry_md_setkey( ctx_, key.getBuf(), key.getLength() );
+ if( err )
+ cLog.msg(Log::PRIO_ERR) << "Sha1AuthAlgo::setKey: Failed to set cipher key: " << gpg_strerror( err );
+}
+
+void Sha1AuthAlgo::generate(EncryptedPacket& packet)
+{
+ if(!packet.getAuthTagLength())
+ return;
+
+ gcry_md_reset( ctx_ );
+
+ gcry_md_write( ctx_, packet.getAuthenticatedPortion(), packet.getAuthenticatedPortionLength() );
+ gcry_md_final( ctx_ );
+
+ u_int8_t* tag = packet.getAuthTag();
+ if(packet.getAuthTagLength() > MAX_LENGTH_)
+ std::memset(tag, 0, (packet.getAuthTagLength() - MAX_LENGTH_));
+
+ u_int8_t* hmac = gcry_md_read(ctx_, 0);
+ u_int32_t length = (packet.getAuthTagLength() < MAX_LENGTH_) ? packet.getAuthTagLength() : MAX_LENGTH_;
+ std::memcpy(&tag[packet.getAuthTagLength() - length], &hmac[MAX_LENGTH_ - length], length);
+}
+
+bool Sha1AuthAlgo::checkTag(EncryptedPacket& packet)
+{
+ if(!packet.getAuthTagLength())
+ return true;
+
+ gcry_md_reset( ctx_ );
+
+ gcry_md_write( ctx_, packet.getAuthenticatedPortion(), packet.getAuthenticatedPortionLength() );
+ gcry_md_final( ctx_ );
+
+ u_int8_t* tag = packet.getAuthTag();
+ if(packet.getAuthTagLength() > MAX_LENGTH_)
+ for(u_int32_t i=0; i < (packet.getAuthTagLength() - MAX_LENGTH_); ++i)
+ if(tag[i]) return false;
+
+ u_int8_t* hmac = gcry_md_read(ctx_, 0);
+ u_int32_t length = (packet.getAuthTagLength() < MAX_LENGTH_) ? packet.getAuthTagLength() : MAX_LENGTH_;
+ if(std::memcmp(&tag[packet.getAuthTagLength() - length], &hmac[MAX_LENGTH_ - length], length))
+ return false;
+
+ return true;
+}
+
+u_int32_t Sha1AuthAlgo::getMaxLength()
+{
+ return MAX_LENGTH_;
+}