move packet making code to C code

7 files changed, 207 insertions, 133 deletions

diff --git a/src/protocol/CMakeLists.txt b/src/protocol/CMakeLists.txt
index 5c35577..e6db775 100644
--- a/src/protocol/CMakeLists.txt
+++ b/src/protocol/CMakeLists.txt
@@ -27,7 +27,8 @@ set(internal_SRCS
   internal/ssh_pubkey_crypto.c
   internal/ssh_diffie-hellman.h
   internal/ssh_diffie-hellman.c
-  internal/crc32.h
+  internal/crc32.c
+  internal/ssh_packet.c
   internal/fqterm_serialization.h
   internal/fqterm_ssh_auth.h
   internal/fqterm_ssh_const.h
@@ -38,7 +39,6 @@ set(internal_SRCS
   internal/fqterm_ssh2_packet.h
   internal/fqterm_ssh_channel.h
   internal/fqterm_ssh_types.h
-  internal/crc32.cpp
   internal/fqterm_ssh_auth.cpp
   internal/fqterm_ssh_kex.cpp
   internal/fqterm_ssh2_kex.cpp
diff --git a/src/protocol/internal/crc32.cpp b/src/protocol/internal/crc32.c
index 2039ac8..2365730 100644
--- a/src/protocol/internal/crc32.cpp
+++ b/src/protocol/internal/crc32.c
@@ -25,8 +25,7 @@
  */
 #include "crc32.h"
 
-namespace FQTerm {
-static const u_int32_t crc32tab[] =  {
+static const uint32_t crc32tab[] =  {
   0x00000000L, 0x77073096L, 0xee0e612cL, 0x990951baL, 0x076dc419L, 0x706af48fL,
   0xe963a535L, 0x9e6495a3L, 0x0edb8832L, 0x79dcb8a4L, 0xe0d5e91eL, 0x97d2d988L,
   0x09b64c2bL, 0x7eb17cbdL, 0xe7b82d07L, 0x90bf1d91L, 0x1db71064L, 0x6ab020f2L,
@@ -72,13 +71,13 @@ static const u_int32_t crc32tab[] =  {
   0xb40bbe37L, 0xc30c8ea1L, 0x5a05df1bL, 0x2d02ef8dL
 };
 
-u_int32_t ssh_crc32(const u_char *buf, u_int32_t size) {
-  u_int32_t i, crc;
-  
-  crc = 0;
-  for (i = 0; i < size; i++) {
-    crc = crc32tab[(crc ^ buf[i]) &0xff] ^ (crc >> 8);
-  } return crc;
-}
+uint32_t ssh_crc32(const uint8_t *buf, uint32_t size)
+{
+	uint32_t i, crc;
+
+	crc = 0;
+	for (i = 0; i < size; i++)
+		crc = crc32tab[(crc ^ buf[i]) & 0xff] ^ (crc >> 8);
 
-}  // namespace FQTerm
+	return crc;
+}
diff --git a/src/protocol/internal/crc32.h b/src/protocol/internal/crc32.h
index ca95b89..56e3b7b 100644
--- a/src/protocol/internal/crc32.h
+++ b/src/protocol/internal/crc32.h
@@ -26,12 +26,17 @@
 
 #ifndef SSH_CRC32_H
 #define SSH_CRC32_H
-#include "fqterm_ssh_types.h"
 
-namespace FQTerm {
+#include <stdint.h>
 
-u_int32_t ssh_crc32(const u_char *, u_int32_t);
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+uint32_t ssh_crc32(const uint8_t *, uint32_t);
 
-}  // namespace FQTerm
+#ifdef __cplusplus
+}
+#endif
 
 #endif
diff --git a/src/protocol/internal/fqterm_ssh1_packet.cpp b/src/protocol/internal/fqterm_ssh1_packet.cpp
index b1f873b..5e64d45 100644
--- a/src/protocol/internal/fqterm_ssh1_packet.cpp
+++ b/src/protocol/internal/fqterm_ssh1_packet.cpp
@@ -23,23 +23,12 @@
 
 #include "fqterm_serialization.h"
 #include "crc32.h"
+#include "ssh_packet.h"
 
 namespace FQTerm {
 //==============================================================================
 //FQTermSSH1PacketSender
 //==============================================================================
-//==============================================================================
-//
-// SSH1 Packet Structure:
-//  --------------------------------------------------------------------------
-//  | length | padding  | type  |                data                | crc32 |
-//  --------------------------------------------------------------------------
-//  | uint32 | 1-7bytes | uchar |                                    | 4bytes|
-//  --------------------------------------------------------------------------
-//  encrypt = padding + type + data + crc32
-//  length =  type + data + crc32
-//
-//==============================================================================
 
 	FQTermSSH1PacketSender::FQTermSSH1PacketSender()
 	{
@@ -48,29 +37,7 @@ namespace FQTerm {
 
 void FQTermSSH1PacketSender::makePacket()
 {
-	int len, padding_len;
-	uint32_t padding[2];
-	uint8_t *data = buffer_data(&orig_data);
-	size_t data_len = buffer_len(&orig_data);
-
-	len = data_len + 4; //CRC32
-	padding_len = 8 - (len % 8);
-	padding[0] = rand();
-	padding[1] = rand();
-
-	buffer_clear(&data_to_send);
-	buffer_append_be32(&data_to_send, len);
-	buffer_append(&data_to_send, (const uint8_t*)padding, padding_len);
-	buffer_append(&data_to_send, data, data_len);
-	buffer_append_be32(&data_to_send, ssh_crc32(
-				buffer_data(&data_to_send) + 4,
-				buffer_len(&data_to_send) - 4));
-
-	if (cipher->started) {
-		cipher->crypt(cipher, buffer_data(&data_to_send) + 4,
-				buffer_data(&data_to_send) + 4,
-				buffer_len(&data_to_send) - 4);
-	}
+	make_ssh1_packet(&orig_data, &data_to_send, cipher);
 }
 
 //==============================================================================
diff --git a/src/protocol/internal/fqterm_ssh2_packet.cpp b/src/protocol/internal/fqterm_ssh2_packet.cpp
index 9f8fd70..e13cab7 100644
--- a/src/protocol/internal/fqterm_ssh2_packet.cpp
+++ b/src/protocol/internal/fqterm_ssh2_packet.cpp
@@ -23,19 +23,12 @@
 
 #include "fqterm_serialization.h"
 #include "buffer.h"
+#include "ssh_packet.h"
 
 namespace FQTerm {
 //==============================================================================
 //FQTermSSH2PacketSender
 //==============================================================================
-// SSH2 Packet Structure:
-//      uint32    packet_length
-//      byte      padding_length
-//      byte[n1]  payload; n1 = packet_length - padding_length - 1
-//      byte[n2]  random padding; n2 = padding_length
-//      byte[m]   mac (Message Authentication Code - MAC); m = mac_length
-//==============================================================================
-
 void FQTermSSH2PacketSender::makePacket()
 {
 	FQ_TRACE("ssh2packet", 9) << "----------------------------Send "
@@ -46,79 +39,8 @@ void FQTermSSH2PacketSender::makePacket()
 	if (is_compressed_)
 		FQ_VERIFY(false);
 
-	// 1. compute the padding length for padding.
-	int non_padding_len = 4 + 1 + buffer_len(&orig_data);
-
-	int padding_block_len = 8;
-	if (cipher->started && cipher->blkSize > padding_block_len)
-		padding_block_len = cipher->blkSize;
-
-	int padding_len = padding_block_len - (non_padding_len % padding_block_len);
-	if (padding_len < 4)
-		padding_len += padding_block_len;
-
-	// 2. renew the output buffer.
-	int total_len = non_padding_len + padding_len;
-	if (is_mac_)
-		total_len += mac->dgstSize;
-
-	buffer_clear(&data_to_send);
-
-	// 3. Fill the output buffer.
-	int packet_len = 1 + buffer_len(&orig_data) + padding_len;
-
-	buffer_append_be32(&data_to_send, packet_len);
-	buffer_append_byte(&data_to_send, padding_len);
-	buffer_append(&data_to_send, buffer_data(&orig_data), buffer_len(&orig_data));
-
-	uint32_t padding[8]; /* padding at most 256 bits */
-	for (int i = 0; i < 8; i++)
-		padding[i] = rand();
-	buffer_append(&data_to_send, (const uint8_t*)padding, padding_len);
-
-	// 4. Add MAC on the entire unencrypted packet,
-	// including two length fields, 'payload' and 'random padding'.
-	if (is_mac_) {
-		const unsigned char *packet = buffer_data(&data_to_send);
-		int len = buffer_len(&data_to_send);
-
-		uint8_t digest[MAX_DGSTLEN];
-
-		buffer mbuffer;
-		buffer_init(&mbuffer);
-		buffer_append_be32(&mbuffer, sequence_no_);
-		buffer_append(&mbuffer, packet, len);
-		mac->getmac(mac, buffer_data(&mbuffer), buffer_len(&mbuffer), digest);
-		buffer_deinit(&mbuffer);
-
-		buffer_append(&data_to_send, digest, mac->dgstSize);
-	}
-
-	if (is_compressed_) {
-		FQ_VERIFY(false);
-	}
-
-	if (cipher->started) {
-		// as RFC 4253:
-		// When encryption is in effect, the packet length, padding
-		// length, payload, and padding fields of each packet MUST be encrypted
-		// with the given algorithm.
-
-		uint8_t *data = buffer_data(&data_to_send);
-		int len = buffer_len(&data_to_send) - mac->dgstSize;
-
-		FQ_TRACE("ssh2packet", 9) << "An packet (without MAC) to be encrypted:" 
-			<< len << " bytes:\n" 
-			<< dumpHexString << std::string((const char *)data, len);
-
-		FQ_VERIFY(cipher->crypt(cipher, data, data, len)==1);
-
-		FQ_TRACE("ssh2packet", 9) << "An encrypted packet (without MAC) made:" 
-			<< len << " bytes:\n" 
-			<< dumpHexString << std::string((const char *)data, len);
-	} 
-
-	++sequence_no_;
+	make_ssh2_packet(&orig_data, &data_to_send, cipher,
+			mac, is_mac_, &sequence_no_);
 }
 
 //==============================================================================
diff --git a/src/protocol/internal/ssh_packet.c b/src/protocol/internal/ssh_packet.c
new file mode 100644
index 0000000..6aad6d9
--- /dev/null
+++ b/src/protocol/internal/ssh_packet.c
@@ -0,0 +1,142 @@
+/*
+ * ssh_packet.c: SSH packet maker
+ * Copyright (C) 2018  Iru Cai <mytbk920423@gmail.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+#include "ssh_packet.h"
+#include "crc32.h"
+#include "ssh_error.h"
+
+//==============================================================================
+//
+// SSH1 Packet Structure:
+//  --------------------------------------------------------------------------
+//  | length | padding  | type  |                data                | crc32 |
+//  --------------------------------------------------------------------------
+//  | uint32 | 1-7bytes | uchar |                                    | 4bytes|
+//  --------------------------------------------------------------------------
+//  encrypt = padding + type + data + crc32
+//  length =  type + data + crc32
+//
+//==============================================================================
+void make_ssh1_packet(buffer *orig_data, buffer *data_to_send,
+		      SSH_CIPHER *cipher)
+{
+	int len, padding_len;
+	uint32_t padding[2];
+	uint8_t *data = buffer_data(orig_data);
+	size_t data_len = buffer_len(orig_data);
+
+	len = data_len + 4; //CRC32
+	padding_len = 8 - (len % 8);
+	padding[0] = rand();
+	padding[1] = rand();
+
+	buffer_clear(data_to_send);
+	buffer_append_be32(data_to_send, len);
+	buffer_append(data_to_send, (const uint8_t *)padding, padding_len);
+	buffer_append(data_to_send, data, data_len);
+	buffer_append_be32(data_to_send,
+			   ssh_crc32(buffer_data(data_to_send) + 4,
+				     buffer_len(data_to_send) - 4));
+
+	if (cipher->started) {
+		cipher->crypt(cipher, buffer_data(data_to_send) + 4,
+			      buffer_data(data_to_send) + 4,
+			      buffer_len(data_to_send) - 4);
+	}
+}
+
+//==============================================================================
+// SSH2 Packet Structure:
+//      uint32    packet_length
+//      byte      padding_length
+//      byte[n1]  payload; n1 = packet_length - padding_length - 1
+//      byte[n2]  random padding; n2 = padding_length
+//      byte[m]   mac (Message Authentication Code - MAC); m = mac_length
+//==============================================================================
+int make_ssh2_packet(buffer *orig_data, buffer *data_to_send,
+		     SSH_CIPHER *cipher, SSH_MAC *mac, bool is_mac_,
+		     uint32_t *seq)
+{
+	// 1. compute the padding length for padding.
+	int non_padding_len = 4 + 1 + buffer_len(orig_data);
+
+	int padding_block_len = 8;
+	if (cipher->started && cipher->blkSize > padding_block_len)
+		padding_block_len = cipher->blkSize;
+
+	int padding_len =
+		padding_block_len - (non_padding_len % padding_block_len);
+	if (padding_len < 4)
+		padding_len += padding_block_len;
+
+	// 2. renew the output buffer.
+	int total_len = non_padding_len + padding_len;
+	if (is_mac_)
+		total_len += mac->dgstSize;
+
+	buffer_clear(data_to_send);
+
+	// 3. Fill the output buffer.
+	int packet_len = 1 + buffer_len(orig_data) + padding_len;
+
+	buffer_append_be32(data_to_send, packet_len);
+	buffer_append_byte(data_to_send, padding_len);
+	buffer_append(data_to_send, buffer_data(orig_data),
+		      buffer_len(orig_data));
+
+	uint32_t padding[8]; /* padding at most 256 bits */
+	for (int i = 0; i < 8; i++)
+		padding[i] = rand();
+	buffer_append(data_to_send, (const uint8_t *)padding, padding_len);
+
+	// 4. Add MAC on the entire unencrypted packet,
+	// including two length fields, 'payload' and 'random padding'.
+	if (is_mac_) {
+		const unsigned char *packet = buffer_data(data_to_send);
+		int len = buffer_len(data_to_send);
+
+		uint8_t digest[MAX_DGSTLEN];
+
+		buffer mbuffer;
+		buffer_init(&mbuffer);
+		buffer_append_be32(&mbuffer, *seq);
+		buffer_append(&mbuffer, packet, len);
+		mac->getmac(mac, buffer_data(&mbuffer), buffer_len(&mbuffer),
+			    digest);
+		buffer_deinit(&mbuffer);
+
+		buffer_append(data_to_send, digest, mac->dgstSize);
+	}
+
+	if (cipher->started) {
+		// as RFC 4253:
+		// When encryption is in effect, the packet length, padding
+		// length, payload, and padding fields of each packet MUST be encrypted
+		// with the given algorithm.
+
+		uint8_t *data = buffer_data(data_to_send);
+		int len = buffer_len(data_to_send) - mac->dgstSize;
+
+		if (cipher->crypt(cipher, data, data, len) != 1)
+			return -ECRYPT;
+	}
+
+	*seq = *seq + 1;
+	return 0;
+}
diff --git a/src/protocol/internal/ssh_packet.h b/src/protocol/internal/ssh_packet.h
new file mode 100644
index 0000000..d8cdaf2
--- /dev/null
+++ b/src/protocol/internal/ssh_packet.h
@@ -0,0 +1,39 @@
+/*
+ * ssh_packet.h: SSH packet maker
+ * Copyright (C) 2018  Iru Cai <mytbk920423@gmail.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+#ifndef SSH_PACKET_H
+#define SSH_PACKET_H
+
+#include "buffer.h"
+#include "ssh_cipher.h"
+#include "ssh_mac.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif /* } */
+
+void make_ssh1_packet(buffer *src, buffer *dest, SSH_CIPHER *);
+int make_ssh2_packet(buffer *src, buffer *dest, SSH_CIPHER *,
+		SSH_MAC *, bool is_mac_, uint32_t *seq);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif