From 593b92e5be8805e32ef43d9208ed0e7a4acf83df Mon Sep 17 00:00:00 2001 From: Iru Cai Date: Thu, 17 May 2018 12:29:57 +0800 Subject: move packet making code to C code --- src/protocol/CMakeLists.txt | 4 +- src/protocol/internal/crc32.c | 83 ++++++++++++++++ src/protocol/internal/crc32.cpp | 84 ---------------- src/protocol/internal/crc32.h | 13 ++- src/protocol/internal/fqterm_ssh1_packet.cpp | 37 +------ src/protocol/internal/fqterm_ssh2_packet.cpp | 84 +--------------- src/protocol/internal/ssh_packet.c | 142 +++++++++++++++++++++++++++ src/protocol/internal/ssh_packet.h | 39 ++++++++ 8 files changed, 280 insertions(+), 206 deletions(-) create mode 100644 src/protocol/internal/crc32.c delete mode 100644 src/protocol/internal/crc32.cpp create mode 100644 src/protocol/internal/ssh_packet.c create mode 100644 src/protocol/internal/ssh_packet.h 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.c b/src/protocol/internal/crc32.c new file mode 100644 index 0000000..2365730 --- /dev/null +++ b/src/protocol/internal/crc32.c @@ -0,0 +1,83 @@ +/* $OpenBSD: crc32.c,v 1.9 2003/02/12 21:39:50 markus Exp $ */ + +/* + * Copyright (c) 2003 Markus Friedl. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR + * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. + * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT + * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF + * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ +#include "crc32.h" + +static const uint32_t crc32tab[] = { + 0x00000000L, 0x77073096L, 0xee0e612cL, 0x990951baL, 0x076dc419L, 0x706af48fL, + 0xe963a535L, 0x9e6495a3L, 0x0edb8832L, 0x79dcb8a4L, 0xe0d5e91eL, 0x97d2d988L, + 0x09b64c2bL, 0x7eb17cbdL, 0xe7b82d07L, 0x90bf1d91L, 0x1db71064L, 0x6ab020f2L, + 0xf3b97148L, 0x84be41deL, 0x1adad47dL, 0x6ddde4ebL, 0xf4d4b551L, 0x83d385c7L, + 0x136c9856L, 0x646ba8c0L, 0xfd62f97aL, 0x8a65c9ecL, 0x14015c4fL, 0x63066cd9L, + 0xfa0f3d63L, 0x8d080df5L, 0x3b6e20c8L, 0x4c69105eL, 0xd56041e4L, 0xa2677172L, + 0x3c03e4d1L, 0x4b04d447L, 0xd20d85fdL, 0xa50ab56bL, 0x35b5a8faL, 0x42b2986cL, + 0xdbbbc9d6L, 0xacbcf940L, 0x32d86ce3L, 0x45df5c75L, 0xdcd60dcfL, 0xabd13d59L, + 0x26d930acL, 0x51de003aL, 0xc8d75180L, 0xbfd06116L, 0x21b4f4b5L, 0x56b3c423L, + 0xcfba9599L, 0xb8bda50fL, 0x2802b89eL, 0x5f058808L, 0xc60cd9b2L, 0xb10be924L, + 0x2f6f7c87L, 0x58684c11L, 0xc1611dabL, 0xb6662d3dL, 0x76dc4190L, 0x01db7106L, + 0x98d220bcL, 0xefd5102aL, 0x71b18589L, 0x06b6b51fL, 0x9fbfe4a5L, 0xe8b8d433L, + 0x7807c9a2L, 0x0f00f934L, 0x9609a88eL, 0xe10e9818L, 0x7f6a0dbbL, 0x086d3d2dL, + 0x91646c97L, 0xe6635c01L, 0x6b6b51f4L, 0x1c6c6162L, 0x856530d8L, 0xf262004eL, + 0x6c0695edL, 0x1b01a57bL, 0x8208f4c1L, 0xf50fc457L, 0x65b0d9c6L, 0x12b7e950L, + 0x8bbeb8eaL, 0xfcb9887cL, 0x62dd1ddfL, 0x15da2d49L, 0x8cd37cf3L, 0xfbd44c65L, + 0x4db26158L, 0x3ab551ceL, 0xa3bc0074L, 0xd4bb30e2L, 0x4adfa541L, 0x3dd895d7L, + 0xa4d1c46dL, 0xd3d6f4fbL, 0x4369e96aL, 0x346ed9fcL, 0xad678846L, 0xda60b8d0L, + 0x44042d73L, 0x33031de5L, 0xaa0a4c5fL, 0xdd0d7cc9L, 0x5005713cL, 0x270241aaL, + 0xbe0b1010L, 0xc90c2086L, 0x5768b525L, 0x206f85b3L, 0xb966d409L, 0xce61e49fL, + 0x5edef90eL, 0x29d9c998L, 0xb0d09822L, 0xc7d7a8b4L, 0x59b33d17L, 0x2eb40d81L, + 0xb7bd5c3bL, 0xc0ba6cadL, 0xedb88320L, 0x9abfb3b6L, 0x03b6e20cL, 0x74b1d29aL, + 0xead54739L, 0x9dd277afL, 0x04db2615L, 0x73dc1683L, 0xe3630b12L, 0x94643b84L, + 0x0d6d6a3eL, 0x7a6a5aa8L, 0xe40ecf0bL, 0x9309ff9dL, 0x0a00ae27L, 0x7d079eb1L, + 0xf00f9344L, 0x8708a3d2L, 0x1e01f268L, 0x6906c2feL, 0xf762575dL, 0x806567cbL, + 0x196c3671L, 0x6e6b06e7L, 0xfed41b76L, 0x89d32be0L, 0x10da7a5aL, 0x67dd4accL, + 0xf9b9df6fL, 0x8ebeeff9L, 0x17b7be43L, 0x60b08ed5L, 0xd6d6a3e8L, 0xa1d1937eL, + 0x38d8c2c4L, 0x4fdff252L, 0xd1bb67f1L, 0xa6bc5767L, 0x3fb506ddL, 0x48b2364bL, + 0xd80d2bdaL, 0xaf0a1b4cL, 0x36034af6L, 0x41047a60L, 0xdf60efc3L, 0xa867df55L, + 0x316e8eefL, 0x4669be79L, 0xcb61b38cL, 0xbc66831aL, 0x256fd2a0L, 0x5268e236L, + 0xcc0c7795L, 0xbb0b4703L, 0x220216b9L, 0x5505262fL, 0xc5ba3bbeL, 0xb2bd0b28L, + 0x2bb45a92L, 0x5cb36a04L, 0xc2d7ffa7L, 0xb5d0cf31L, 0x2cd99e8bL, 0x5bdeae1dL, + 0x9b64c2b0L, 0xec63f226L, 0x756aa39cL, 0x026d930aL, 0x9c0906a9L, 0xeb0e363fL, + 0x72076785L, 0x05005713L, 0x95bf4a82L, 0xe2b87a14L, 0x7bb12baeL, 0x0cb61b38L, + 0x92d28e9bL, 0xe5d5be0dL, 0x7cdcefb7L, 0x0bdbdf21L, 0x86d3d2d4L, 0xf1d4e242L, + 0x68ddb3f8L, 0x1fda836eL, 0x81be16cdL, 0xf6b9265bL, 0x6fb077e1L, 0x18b74777L, + 0x88085ae6L, 0xff0f6a70L, 0x66063bcaL, 0x11010b5cL, 0x8f659effL, 0xf862ae69L, + 0x616bffd3L, 0x166ccf45L, 0xa00ae278L, 0xd70dd2eeL, 0x4e048354L, 0x3903b3c2L, + 0xa7672661L, 0xd06016f7L, 0x4969474dL, 0x3e6e77dbL, 0xaed16a4aL, 0xd9d65adcL, + 0x40df0b66L, 0x37d83bf0L, 0xa9bcae53L, 0xdebb9ec5L, 0x47b2cf7fL, 0x30b5ffe9L, + 0xbdbdf21cL, 0xcabac28aL, 0x53b39330L, 0x24b4a3a6L, 0xbad03605L, 0xcdd70693L, + 0x54de5729L, 0x23d967bfL, 0xb3667a2eL, 0xc4614ab8L, 0x5d681b02L, 0x2a6f2b94L, + 0xb40bbe37L, 0xc30c8ea1L, 0x5a05df1bL, 0x2d02ef8dL +}; + +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); + + return crc; +} diff --git a/src/protocol/internal/crc32.cpp b/src/protocol/internal/crc32.cpp deleted file mode 100644 index 2039ac8..0000000 --- a/src/protocol/internal/crc32.cpp +++ /dev/null @@ -1,84 +0,0 @@ -/* $OpenBSD: crc32.c,v 1.9 2003/02/12 21:39:50 markus Exp $ */ - -/* - * Copyright (c) 2003 Markus Friedl. All rights reserved. - * - * Redistribution and use in source and binary forms, with or without - * modification, are permitted provided that the following conditions - * are met: - * 1. Redistributions of source code must retain the above copyright - * notice, this list of conditions and the following disclaimer. - * 2. Redistributions in binary form must reproduce the above copyright - * notice, this list of conditions and the following disclaimer in the - * documentation and/or other materials provided with the distribution. - * - * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR - * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES - * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. - * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, - * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT - * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, - * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY - * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT - * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF - * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. - */ -#include "crc32.h" - -namespace FQTerm { -static const u_int32_t crc32tab[] = { - 0x00000000L, 0x77073096L, 0xee0e612cL, 0x990951baL, 0x076dc419L, 0x706af48fL, - 0xe963a535L, 0x9e6495a3L, 0x0edb8832L, 0x79dcb8a4L, 0xe0d5e91eL, 0x97d2d988L, - 0x09b64c2bL, 0x7eb17cbdL, 0xe7b82d07L, 0x90bf1d91L, 0x1db71064L, 0x6ab020f2L, - 0xf3b97148L, 0x84be41deL, 0x1adad47dL, 0x6ddde4ebL, 0xf4d4b551L, 0x83d385c7L, - 0x136c9856L, 0x646ba8c0L, 0xfd62f97aL, 0x8a65c9ecL, 0x14015c4fL, 0x63066cd9L, - 0xfa0f3d63L, 0x8d080df5L, 0x3b6e20c8L, 0x4c69105eL, 0xd56041e4L, 0xa2677172L, - 0x3c03e4d1L, 0x4b04d447L, 0xd20d85fdL, 0xa50ab56bL, 0x35b5a8faL, 0x42b2986cL, - 0xdbbbc9d6L, 0xacbcf940L, 0x32d86ce3L, 0x45df5c75L, 0xdcd60dcfL, 0xabd13d59L, - 0x26d930acL, 0x51de003aL, 0xc8d75180L, 0xbfd06116L, 0x21b4f4b5L, 0x56b3c423L, - 0xcfba9599L, 0xb8bda50fL, 0x2802b89eL, 0x5f058808L, 0xc60cd9b2L, 0xb10be924L, - 0x2f6f7c87L, 0x58684c11L, 0xc1611dabL, 0xb6662d3dL, 0x76dc4190L, 0x01db7106L, - 0x98d220bcL, 0xefd5102aL, 0x71b18589L, 0x06b6b51fL, 0x9fbfe4a5L, 0xe8b8d433L, - 0x7807c9a2L, 0x0f00f934L, 0x9609a88eL, 0xe10e9818L, 0x7f6a0dbbL, 0x086d3d2dL, - 0x91646c97L, 0xe6635c01L, 0x6b6b51f4L, 0x1c6c6162L, 0x856530d8L, 0xf262004eL, - 0x6c0695edL, 0x1b01a57bL, 0x8208f4c1L, 0xf50fc457L, 0x65b0d9c6L, 0x12b7e950L, - 0x8bbeb8eaL, 0xfcb9887cL, 0x62dd1ddfL, 0x15da2d49L, 0x8cd37cf3L, 0xfbd44c65L, - 0x4db26158L, 0x3ab551ceL, 0xa3bc0074L, 0xd4bb30e2L, 0x4adfa541L, 0x3dd895d7L, - 0xa4d1c46dL, 0xd3d6f4fbL, 0x4369e96aL, 0x346ed9fcL, 0xad678846L, 0xda60b8d0L, - 0x44042d73L, 0x33031de5L, 0xaa0a4c5fL, 0xdd0d7cc9L, 0x5005713cL, 0x270241aaL, - 0xbe0b1010L, 0xc90c2086L, 0x5768b525L, 0x206f85b3L, 0xb966d409L, 0xce61e49fL, - 0x5edef90eL, 0x29d9c998L, 0xb0d09822L, 0xc7d7a8b4L, 0x59b33d17L, 0x2eb40d81L, - 0xb7bd5c3bL, 0xc0ba6cadL, 0xedb88320L, 0x9abfb3b6L, 0x03b6e20cL, 0x74b1d29aL, - 0xead54739L, 0x9dd277afL, 0x04db2615L, 0x73dc1683L, 0xe3630b12L, 0x94643b84L, - 0x0d6d6a3eL, 0x7a6a5aa8L, 0xe40ecf0bL, 0x9309ff9dL, 0x0a00ae27L, 0x7d079eb1L, - 0xf00f9344L, 0x8708a3d2L, 0x1e01f268L, 0x6906c2feL, 0xf762575dL, 0x806567cbL, - 0x196c3671L, 0x6e6b06e7L, 0xfed41b76L, 0x89d32be0L, 0x10da7a5aL, 0x67dd4accL, - 0xf9b9df6fL, 0x8ebeeff9L, 0x17b7be43L, 0x60b08ed5L, 0xd6d6a3e8L, 0xa1d1937eL, - 0x38d8c2c4L, 0x4fdff252L, 0xd1bb67f1L, 0xa6bc5767L, 0x3fb506ddL, 0x48b2364bL, - 0xd80d2bdaL, 0xaf0a1b4cL, 0x36034af6L, 0x41047a60L, 0xdf60efc3L, 0xa867df55L, - 0x316e8eefL, 0x4669be79L, 0xcb61b38cL, 0xbc66831aL, 0x256fd2a0L, 0x5268e236L, - 0xcc0c7795L, 0xbb0b4703L, 0x220216b9L, 0x5505262fL, 0xc5ba3bbeL, 0xb2bd0b28L, - 0x2bb45a92L, 0x5cb36a04L, 0xc2d7ffa7L, 0xb5d0cf31L, 0x2cd99e8bL, 0x5bdeae1dL, - 0x9b64c2b0L, 0xec63f226L, 0x756aa39cL, 0x026d930aL, 0x9c0906a9L, 0xeb0e363fL, - 0x72076785L, 0x05005713L, 0x95bf4a82L, 0xe2b87a14L, 0x7bb12baeL, 0x0cb61b38L, - 0x92d28e9bL, 0xe5d5be0dL, 0x7cdcefb7L, 0x0bdbdf21L, 0x86d3d2d4L, 0xf1d4e242L, - 0x68ddb3f8L, 0x1fda836eL, 0x81be16cdL, 0xf6b9265bL, 0x6fb077e1L, 0x18b74777L, - 0x88085ae6L, 0xff0f6a70L, 0x66063bcaL, 0x11010b5cL, 0x8f659effL, 0xf862ae69L, - 0x616bffd3L, 0x166ccf45L, 0xa00ae278L, 0xd70dd2eeL, 0x4e048354L, 0x3903b3c2L, - 0xa7672661L, 0xd06016f7L, 0x4969474dL, 0x3e6e77dbL, 0xaed16a4aL, 0xd9d65adcL, - 0x40df0b66L, 0x37d83bf0L, 0xa9bcae53L, 0xdebb9ec5L, 0x47b2cf7fL, 0x30b5ffe9L, - 0xbdbdf21cL, 0xcabac28aL, 0x53b39330L, 0x24b4a3a6L, 0xbad03605L, 0xcdd70693L, - 0x54de5729L, 0x23d967bfL, 0xb3667a2eL, 0xc4614ab8L, 0x5d681b02L, 0x2a6f2b94L, - 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; -} - -} // namespace FQTerm 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 -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 @@ -23,22 +23,11 @@ #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 + * + * 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 + * + * 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 -- cgit v1.2.3