* added key derivation functions

7 files changed, 225 insertions, 16 deletions

diff --git a/Makefile b/Makefile
index 7314b20..e416cbc 100644
--- a/Makefile
+++ b/Makefile
@@ -36,6 +36,7 @@ OBJS = anytun.o \
        packet.o \
        cypher.o \
        authAlgo.o \
+			 keyDerivation.o \
        PracticalSocket.o \
        signalController.o \
        log.o \
@@ -68,6 +69,9 @@ cypher.o: cypher.cpp cypher.h buffer.h
 authAlgo.o: authAlgo.cpp authAlgo.h buffer.h
 	$(C++) $(CCFLAGS) $< -c
 
+keyDerivation.o: keyDerivation.cpp keyDerivation.h
+	$(C++) $(CCFLAGS) $< -c
+
 signalController.o: signalController.cpp signalController.h
 	$(C++) $(CCFLAGS) $< -c
 
diff --git a/authAlgo.cpp b/authAlgo.cpp
index 57c9ee6..206d335 100644
--- a/authAlgo.cpp
+++ b/authAlgo.cpp
@@ -30,7 +30,37 @@
 
 #include "authAlgo.h"
 
+extern "C" {
+#include <srtp/crypto_kernel.h>
+}
+
+
 auth_tag_t NullAuthAlgo::calc(const Buffer& buf)
 {
   return 0;
 }
+
+
+// HMAC_SHA1
+auth_tag_t HmacAuthAlgo::calc(const Buffer& buf)
+{
+  extern auth_type_t hmac;
+  err_status_t status = err_status_ok;
+  auth_t *auth = NULL;
+
+  uint8_t key[] = {
+    0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+    0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
+    0x10, 0x11, 0x12, 0x13
+  };
+
+  // auth_type_alloc(auth_type, auth, key_len, out_len)
+  status = auth_type_alloc(&hmac, &auth, 94, 4);
+  status = auth_init(auth, key);
+
+  status = auth_dealloc(auth);
+
+  return 0;
+}
+
+
diff --git a/authAlgo.h b/authAlgo.h
index 2c420e2..7c7ca6d 100644
--- a/authAlgo.h
+++ b/authAlgo.h
@@ -49,4 +49,12 @@ public:
   auth_tag_t calc(const Buffer& buf);
 };
 
+
+// HMAC_SHA1
+class HmacAuthAlgo : public AuthAlgo
+{
+public:
+  auth_tag_t calc(const Buffer& buf);
+};
+
 #endif
diff --git a/cypher.cpp b/cypher.cpp
index 76a7d92..c77f883 100644
--- a/cypher.cpp
+++ b/cypher.cpp
@@ -31,8 +31,6 @@
 #include <stdexcept>
 #include <vector>
 
-//#include "datatypes.h"
-
 #include "cypher.h"
 
 extern "C" {
@@ -63,17 +61,15 @@ Buffer NullCypher::getBitStream(u_int32_t length, seq_nr_t seq_nr, sender_id_t s
   return buf;
 }
 
-void AesIcmCypher::cypher(Buffer& buf, seq_nr_t seq_nr, sender_id_t sender_id)
-{
-}
 
-Buffer AesIcmCypher::getBitStream(u_int32_t length, seq_nr_t seq_nr, sender_id_t sender_id)
+void AesIcmCypher::cypher(Buffer& buf, seq_nr_t seq_nr, sender_id_t sender_id)
 {
-  Buffer buf(length);
   extern cipher_type_t aes_icm;
-  err_status_t status;
+  err_status_t status = err_status_ok;
   cipher_t* cipher = NULL;
-  uint8_t key[20] = {
+  uint32_t length = 0;
+
+  uint8_t key[] = {
     0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
     0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
     0x10, 0x11, 0x12, 0x13
@@ -84,13 +80,9 @@ Buffer AesIcmCypher::getBitStream(u_int32_t length, seq_nr_t seq_nr, sender_id_t
 
   // allocate cipher
   status = cipher_type_alloc(&aes_icm, &cipher, 30);
-  if(status)
-    return buf;
 
   // init cipher
   status = cipher_init(cipher, key, direction_any);
-  if(status)
-    return buf;
 
   //set iv
   //  where the 128-bit integer value IV SHALL be defined by the SSRC, the
@@ -100,17 +92,18 @@ Buffer AesIcmCypher::getBitStream(u_int32_t length, seq_nr_t seq_nr, sender_id_t
 
   // sizeof(k_s) = 112, random
 
-
   iv.v32[0] ^= 0;
   iv.v32[1] ^= sender_id; 
   iv.v32[2] ^= (seq_nr >> 16);
   iv.v32[3] ^= (seq_nr << 16);
 
+
   status = cipher_set_iv(cipher, &iv);
+
+  length = buf.getLength();
   
-  status = cipher_output(cipher, buf, length);
+  status = cipher_encrypt(cipher, buf, &length);
   status = cipher_dealloc(cipher);
-  return buf;
 }
 
 
diff --git a/cypher.h b/cypher.h
index 689d230..48e2ef9 100644
--- a/cypher.h
+++ b/cypher.h
@@ -61,6 +61,9 @@ public:
 
 protected:
   Buffer getBitStream(u_int32_t length, seq_nr_t seq_nr, sender_id_t sender_id);
+
+private:
+
 };
 
 #endif
diff --git a/keyDerivation.cpp b/keyDerivation.cpp
new file mode 100644
index 0000000..5663ac1
--- /dev/null
+++ b/keyDerivation.cpp
@@ -0,0 +1,105 @@
+/*
+ *  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 "keyDerivation.h"
+
+extern "C" {
+#include <srtp/crypto_kernel.h>
+}
+
+err_status_t KeyDerivation::init(const uint8_t key[30], const uint8_t salt[14])
+{
+  aes_icm_context_init(&kdf_, key);
+
+  for(uint8_t i = 0; i < 14; i++)
+    salt_[i] = salt[i];
+
+  return err_status_ok;
+}
+
+err_status_t KeyDerivation::setLogKDRate(const uint8_t log_rate)
+{
+  if( log_rate < 49 )
+  {
+    ld_kdr_ = log_rate;
+    return err_status_ok;
+  }
+  return err_status_bad_param;
+}
+
+
+err_status_t KeyDerivation::generate(satp_prf_label label, seq_nr_t seq_nr, uint8_t *key, int length)
+{
+  v128_t iv, salt, key_id;
+  uint8_t r = 0;
+
+  v128_set_to_zero(&iv);
+  v128_set_to_zero(&salt);
+  v128_set_to_zero(&key_id);
+
+  // look at: http://tools.ietf.org/html/rfc3711#section-4.3
+  if( ld_kdr_ == -1 )    // means key_derivation_rate = 0
+    r = 0;
+  else
+    // FIXXME: kdr can be greater than 2^32 (= 2^48)
+    r = seq_nr / ( 0x01 << ld_kdr_ );
+
+  key_id.v32[0] = (label << 8);
+  key_id.v32[0] += r;
+
+  v128_copy_octet_string(&salt, salt_);
+  v128_xor(&iv, &salt, &key_id);
+
+  aes_icm_set_iv(&kdf_, &iv);
+
+  /* generate keystream output */
+  aes_icm_output(&kdf_, key, length);
+
+  return err_status_ok;
+}
+
+
+err_status_t KeyDerivation::clear() 
+{
+  /* zeroize aes context */
+
+  v128_set_to_zero(&kdf_.counter);
+  v128_set_to_zero(&kdf_.offset);
+  v128_set_to_zero(&kdf_.keystream_buffer);
+  for(uint8_t i = 0; i < 11; i++)
+  {
+    v128_set_to_zero(&kdf_.expanded_key[i]);
+  }
+  kdf_.bytes_in_buffer = 0;
+
+  return err_status_ok;
+}
+
diff --git a/keyDerivation.h b/keyDerivation.h
new file mode 100644
index 0000000..a625342
--- /dev/null
+++ b/keyDerivation.h
@@ -0,0 +1,66 @@
+/*
+ *  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
+ */
+
+#ifndef _KEYDERIVATION_H_
+#define _KEYDERIVATION_H_
+
+#include "datatypes.h"
+#include "buffer.h"
+
+
+extern "C" {
+  #include <srtp/crypto_kernel.h>
+}
+
+
+typedef enum {
+  label_satp_encryption  = 0x00,
+  label_satp_msg_auth    = 0x01,
+  label_satp_salt        = 0x02,
+} satp_prf_label;
+
+class KeyDerivation
+{
+public:
+  KeyDerivation() : ld_kdr_(-1) {};
+  virtual ~KeyDerivation() {};
+
+  err_status_t init(const uint8_t key[30], const uint8_t salt[14]);
+  err_status_t setLogKDRate(const uint8_t ld_rate);
+  err_status_t generate(satp_prf_label label, seq_nr_t seq_nr, uint8_t *key, int length);
+  err_status_t clear();
+
+protected:
+  aes_icm_ctx_t kdf_;
+  int8_t ld_kdr_;     // ld(key_derivation_rate)
+  uint8_t salt_[14];
+};
+
+#endif