2008-02-16 Tatsuhiro Tsujikawa <tujikawa at rednoah dot com>

	Added Message Stream Encryption(MSE) support.
	Currently, aria2 accepts incoming connections with Obfuscation Header
	and legacy BitTorrent Header and establishes connections with
	Obfuscation Header first and if failed then retry with legacy
	BitTorrent header. If plain text and ARC4 is provided, aria2 always
	choose ARC4. The new option to change the default behavior is planned.
	For tracker extension, "supportcrypto=1" is added statically.
	* src/PeerInitiateConnectionCommand.{h, cc}
	* src/PeerConnection.{h, cc}
	* src/HandleRegistry.h
	* src/SocketCore.h
	* src/PeerReceiveHandshakeCommand.{h, cc}
	* src/BtRegistry.{h, cc}
	* src/PeerListenCommand.cc
	* src/InitiatorMSEHandshakeCommand.{h, cc}
	* src/ReceiverMSEHandshakeCommand.{h, cc}
	* src/MSEHandshake.{h, cc}
	* src/ARC4Encryptor.h
	* src/ARC4Decryptor.h
	* src/LibgcryptARC4Encryptor.h
	* src/LibgcryptARC4Decryptor.h
	* src/LibgcryptARC4Context.h
	* src/LibsslARC4Encryptor.h
	* src/LibsslARC4Decryptor.h
	* src/LibsslARC4Context.h
	* src/DHKeyExchange.h
	* src/LibgcryptDHKeyExchange.h
	* src/LibsslDHKeyExchange.h
	* src/DefaultBtAnnounce.cc: Just added "supportcrypto=1" parameter.
	* test/DefaultBtAnnounceTest.cc
	* test/ARC4Test.cc
	* test/DHKeyExchangeTest.cc
	
	Removed prepareForRetry() because it is not used.
	* src/PeerAbstractCommand.{h, cc}
	* src/PeerInteractionCommand.{h, cc}
	* src/PeerInitiateConnectionCommand.{h, cc}

1 files changed, 171 insertions, 0 deletions

diff --git a/src/LibsslDHKeyExchange.h b/src/LibsslDHKeyExchange.h
new file mode 100644
index 00000000..1f311d15
--- /dev/null
+++ b/src/LibsslDHKeyExchange.h
@@ -0,0 +1,171 @@
+/* <!-- copyright */
+/*
+ * aria2 - The high speed download utility
+ *
+ * Copyright (C) 2006 Tatsuhiro Tsujikawa
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 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; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ * In addition, as a special exception, the copyright holders give
+ * permission to link the code of portions of this program with the
+ * OpenSSL library under certain conditions as described in each
+ * individual source file, and distribute linked combinations
+ * including the two.
+ * You must obey the GNU General Public License in all respects
+ * for all of the code used other than OpenSSL.  If you modify
+ * file(s) with this exception, you may extend this exception to your
+ * version of the file(s), but you are not obligated to do so.  If you
+ * do not wish to do so, delete this exception statement from your
+ * version.  If you delete this exception statement from all source
+ * files in the program, then also delete it here.
+ */
+/* copyright --> */
+#ifndef _D_LIBSSL_DH_KEY_EXCHANGE_H_
+#define _D_LIBSSL_DH_KEY_EXCHANGE_H_
+
+#include "common.h"
+#include "DlAbortEx.h"
+#include <openssl/dh.h>
+#include <openssl/rand.h>
+#include <openssl/err.h>
+
+namespace aria2 {
+
+class DHKeyExchange {
+private:
+
+  BN_CTX* _bnCtx;
+
+  BIGNUM* _prime;
+
+  BIGNUM* _generator;
+
+  BIGNUM* _privateKey;
+
+  BIGNUM* _publicKey;
+
+  void handleError() const
+  {
+    throw new DlAbortEx("Exception in libssl routine(DHKeyExchange class): %s",
+			ERR_error_string(ERR_get_error(), 0));
+  }
+
+public:
+  DHKeyExchange():_bnCtx(0),
+		  _prime(0),
+		  _generator(0),
+		  _privateKey(0),
+		  _publicKey(0) {}
+
+  ~DHKeyExchange()
+  {
+    BN_CTX_free(_bnCtx);
+    BN_free(_prime);
+    BN_free(_generator);
+    BN_free(_privateKey);
+    BN_free(_publicKey);
+  }
+
+  void init(const unsigned char* prime, const unsigned char* generator,
+	    size_t privateKeyBits)
+  {
+    BN_CTX_free(_bnCtx);
+    _bnCtx = BN_CTX_new();
+    if(!_bnCtx) {
+      handleError();
+    }
+
+    BN_free(_prime);
+    _prime = 0;
+    BN_free(_generator);
+    _generator = 0;
+    BN_free(_privateKey);
+    _privateKey = 0;
+
+    if(BN_hex2bn(&_prime, reinterpret_cast<const char*>(prime)) == 0) {
+      handleError();
+    }
+    if(BN_hex2bn(&_generator, reinterpret_cast<const char*>(generator)) == 0) {
+      handleError();
+    }
+    _privateKey = BN_new();
+    if(!BN_rand(_privateKey, privateKeyBits, -1, false)) {
+      handleError();
+    }
+  }
+
+  void generatePublicKey()
+  {
+    BN_free(_publicKey);
+    _publicKey = BN_new();
+    BN_mod_exp(_publicKey, _generator, _privateKey, _prime, _bnCtx);
+  }
+
+  size_t publicKeyLength() const
+  {
+    return BN_num_bytes(_publicKey);
+  }
+
+  size_t getPublicKey(unsigned char* out, size_t outLength) const
+  {
+    if(outLength < publicKeyLength()) {
+      throw new DlAbortEx("Insufficient buffer for public key. expect:%u, actual:%u",
+			  publicKeyLength(), outLength);
+    }
+    size_t nwritten = BN_bn2bin(_publicKey, out);
+    if(!nwritten) {
+      handleError();
+    }
+    return nwritten;
+  }
+
+  void generateNonce(unsigned char* out, size_t outLength) const
+  {
+    if(!RAND_bytes(out, outLength)) {
+      handleError();
+    }
+  }
+
+  size_t computeSecret(unsigned char* out, size_t outLength,
+		       const unsigned char* peerPublicKeyData,
+		       size_t peerPublicKeyLength) const
+  {
+    if(outLength < publicKeyLength()) {
+      throw new DlAbortEx("Insufficient buffer for secret. expect:%u, actual:%u",
+			  publicKeyLength(), outLength);
+    }
+
+
+    BIGNUM* peerPublicKey = BN_bin2bn(peerPublicKeyData, peerPublicKeyLength, 0);
+    if(!peerPublicKey) {
+      handleError();
+    }
+
+    BIGNUM* secret = BN_new();
+    BN_mod_exp(secret, peerPublicKey, _privateKey, _prime, _bnCtx);
+    BN_free(peerPublicKey);
+
+    size_t nwritten = BN_bn2bin(secret, out);
+    BN_free(secret);
+    if(!nwritten) {
+      handleError();
+    }
+    return nwritten;
+  }
+};
+
+} // namespace aria2
+
+#endif // _D_LIBSSL_DH_KEY_EXCHANGE_H_