; ssh.asm - SSH client for KolibriOS
;
; Copyright (C) 2015-2016 Jeffrey Amelynck
;
; 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 3 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, see <http://www.gnu.org/licenses/>.
format binary as ""
__DEBUG__ = 1
__DEBUG_LEVEL__ = 1
BUFFERSIZE = 4096
MAX_BITS = 8192
DH_PRIVATE_KEY_SIZE = 256
use32
db 'MENUET01' ; signature
dd 1 ; header version
dd start ; entry point
dd i_end ; initialized size
dd mem+4096 ; required memory
dd mem+4096 ; stack pointer
dd hostname ; parameters
dd 0 ; path
include '../../macros.inc'
purge mov,add,sub
include '../../proc32.inc'
include '../../dll.inc'
include '../../debug-fdo.inc'
include '../../network.inc'
;include '../../develop/libraries/libcrash/trunk/libcrash.inc'
include 'mcodes.inc'
include 'ssh_transport.inc'
include 'dh_gex.inc'
include 'mpint.inc'
include 'random.inc'
include 'aes256.inc'
include 'aes256-ctr.inc'
include 'aes256-cbc.inc'
include '../../fs/kfar/trunk/kfar_arc/sha256.inc'
; macros for network byte order
macro dd_n op {
dd 0 or (((op) and 0FF000000h) shr 24) or \
(((op) and 000FF0000h) shr 8) or \
(((op) and 00000FF00h) shl 8) or \
(((op) and 0000000FFh) shl 24)
}
macro dw_n op {
dw 0 or (((op) and 0FF00h) shr 8) or \
(((op) and 000FFh) shl 8)
}
start:
mcall 68, 11 ; Init heap
DEBUGF 1, "SSH: Loading libraries\n"
stdcall dll.Load, @IMPORT
test eax, eax
jnz exit
DEBUGF 1, "SSH: Init PRNG\n"
call init_random
DEBUGF 1, "SSH: Init Console\n"
invoke con_start, 1
invoke con_init, 80, 25, 80, 25, title
; Check for parameters
cmp byte[hostname], 0
jne resolve
main:
invoke con_cls
; Welcome user
invoke con_write_asciiz, str1
prompt:
; write prompt
invoke con_write_asciiz, str2
; read string
mov esi, hostname
invoke con_gets, esi, 256
; check for exit
test eax, eax
jz done
cmp byte[esi], 10
jz done
resolve:
mov [sockaddr1.port], 22 shl 8
; delete terminating '\n'
mov esi, hostname
@@:
lodsb
cmp al, ':'
je .do_port
cmp al, 0x20
ja @r
mov byte[esi-1], 0
jmp .done
.do_port:
xor eax, eax
xor ebx, ebx
mov byte[esi-1], 0
.portloop:
lodsb
cmp al, 0x20
jbe .port_done
sub al, '0'
jb hostname_error
cmp al, 9
ja hostname_error
lea ebx, [ebx*4 + ebx]
shl ebx, 1
add ebx, eax
jmp .portloop
.port_done:
xchg bl, bh
mov [sockaddr1.port], bx
.done:
; resolve name
push esp ; reserve stack place
push esp
invoke getaddrinfo, hostname, 0, 0
pop esi
; test for error
test eax, eax
jnz dns_error
invoke con_cls
invoke con_write_asciiz, str3
invoke con_write_asciiz, hostname
; write results
invoke con_write_asciiz, str8
; convert IP address to decimal notation
mov eax, [esi+addrinfo.ai_addr]
mov eax, [eax+sockaddr_in.sin_addr]
mov [sockaddr1.ip], eax
invoke inet_ntoa, eax
; write result
invoke con_write_asciiz, eax
; free allocated memory
invoke freeaddrinfo, esi
invoke con_write_asciiz, str9
mcall 40, EVM_STACK + EVM_KEY
invoke con_cls
; Create socket
mcall socket, AF_INET4, SOCK_STREAM, 0
cmp eax, -1
jz socket_err
mov [socketnum], eax
; Connect
mcall connect, [socketnum], sockaddr1, 18
test eax, eax
jnz socket_err
; Start calculating hash meanwhile
call sha256_init
; HASH: string V_C, the client's version string (CR and NL excluded)
mov esi, ssh_ident_ha
mov edx, ssh_ident.length+4-2
call sha256_update
; Send our identification string
DEBUGF 1, "Sending ID string\n"
mcall send, [socketnum], ssh_ident, ssh_ident.length, 0
cmp eax, -1
je socket_err
; Check protocol version of server
mcall recv, [socketnum], rx_buffer, BUFFERSIZE, 0
cmp eax, -1
je socket_err
DEBUGF 1, "Received ID string\n"
cmp dword[rx_buffer], "SSH-"
jne proto_err
cmp dword[rx_buffer+4], "2.0-"
jne proto_err
; HASH: string V_S, the server's version string (CR and NL excluded)
lea edx, [eax+2]
sub eax, 2
bswap eax
mov [rx_buffer-4], eax
mov esi, rx_buffer-4
call sha256_update
; Key Exchange init
DEBUGF 1, "Sending KEX init\n"
mov edi, ssh_kex.cookie
call MBRandom
stosd
call MBRandom
stosd
call MBRandom
stosd
call MBRandom
stosd
stdcall ssh_send_packet, [socketnum], ssh_kex, ssh_kex.length, 0
cmp eax, -1
je socket_err
; HASH: string I_C, the payload of the client's SSH_MSG_KEXINIT
mov eax, [tx_buffer+ssh_header.length]
bswap eax
movzx ebx, [tx_buffer+ssh_header.padding]
sub eax, ebx
dec eax
lea edx, [eax+4]
bswap eax
mov [tx_buffer+1], eax
mov esi, tx_buffer+1
call sha256_update
; Check key exchange init of server
stdcall ssh_recv_packet, [socketnum], rx_buffer, BUFFERSIZE, 0
cmp eax, -1
je socket_err
cmp [rx_buffer+ssh_header.message_code], SSH_MSG_KEXINIT
jne proto_err
DEBUGF 1, "Received KEX init\n"
lea esi, [rx_buffer+sizeof.ssh_header+16]
lodsd
bswap eax
DEBUGF 1, "kex_algorithms: %s\n", esi
add esi, eax
lodsd
bswap eax
DEBUGF 1, "server_host_key_algorithms: %s\n", esi
add esi, eax
lodsd
bswap eax
DEBUGF 1, "encryption_algorithms_client_to_server: %s\n", esi
add esi, eax
lodsd
bswap eax
DEBUGF 1, "encryption_algorithms_server_to_client: %s\n", esi
add esi, eax
lodsd
bswap eax
DEBUGF 1, "mac_algorithms_client_to_server: %s\n", esi
add esi, eax
lodsd
bswap eax
DEBUGF 1, "mac_algorithms_server_to_client: %s\n", esi
add esi, eax
lodsd
bswap eax
DEBUGF 1, "compression_algorithms_client_to_server: %s\n", esi
add esi, eax
lodsd
bswap eax
DEBUGF 1, "compression_algorithms_server_to_client: %s\n", esi
add esi, eax
lodsd
bswap eax
DEBUGF 1, "languages_client_to_server: %s\n", esi
add esi, eax
lodsd
bswap eax
DEBUGF 1, "languages_server_to_client: %s\n", esi
add esi, eax
lodsb
DEBUGF 1, "KEX First Packet Follows: %u\n", al
; TODO
; HASH: string I_S, the payload of the servers's SSH_MSG_KEXINIT
mov eax, [rx_buffer+ssh_header.length]
movzx ebx, [rx_buffer+ssh_header.padding]
sub eax, ebx
dec eax
lea edx, [eax+4]
bswap eax
mov [rx_buffer+sizeof.ssh_header-5], eax
mov esi, rx_buffer+sizeof.ssh_header-5
call sha256_update
; Exchange keys with the server
stdcall dh_gex
test eax, eax
jnz exit
; Set keys
DEBUGF 1, "SSH: Init encryption\n"
stdcall aes256_cbc_init, rx_iv
mov [rx_context], eax
stdcall aes256_set_encrypt_key, [rx_context], rx_enc_key
mov [decrypt_proc], aes256_cbc_decrypt
mov [rx_blocksize], 32
DEBUGF 1, "SSH: Init decryption\n"
stdcall aes256_cbc_init, tx_iv
mov [tx_context], eax
stdcall aes256_set_decrypt_key, [tx_context], tx_enc_key
mov [encrypt_proc], aes256_cbc_encrypt
mov [tx_blocksize], 32
; Launch network thread
mcall 18, 7
push eax
mcall 51, 1, thread, mem - 2048
pop ecx
mcall 18, 3
mainloop:
call [con_get_flags]
test eax, 0x200 ; con window closed?
jnz exit
stdcall ssh_recv_packet, [socketnum], rx_buffer, BUFFERSIZE, 0
cmp eax, -1
je closed
DEBUGF 1, 'SSH: got %u bytes of data !\n', eax
mov esi, rx_buffer
mov ecx, eax
pusha
@@:
lodsb
DEBUGF 1, "%x ", eax:2
dec ecx
jnz @r
popa
lea edi, [esi + eax]
mov byte [edi], 0
invoke con_write_asciiz, esi
jmp mainloop
proto_err:
DEBUGF 1, "SSH: protocol error\n"
invoke con_write_asciiz, str7
jmp prompt
socket_err:
DEBUGF 1, "SSH: socket error %d\n", ebx
invoke con_write_asciiz, str6
jmp prompt
dns_error:
DEBUGF 1, "SSH: DNS error %d\n", eax
invoke con_write_asciiz, str5
jmp prompt
hostname_error:
invoke con_write_asciiz, str10
jmp prompt
closed:
invoke con_write_asciiz, str11
jmp prompt
done:
invoke con_exit, 1
exit:
DEBUGF 1, "SSH: Exiting\n"
mcall close, [socketnum]
mcall -1
thread:
mcall 40, 0
.loop:
invoke con_getch2
mov [send_data], ax
xor esi, esi
inc esi
test al, al
jnz @f
inc esi
@@:
stdcall ssh_send_packet, [socketnum], send_data, 0
invoke con_get_flags
test eax, 0x200 ; con window closed?
jz .loop
mcall -1
; data
title db 'Secure Shell',0
str1 db 'SSH client for KolibriOS',10,10,\
'Please enter URL of SSH server (host:port)',10,10,0
str2 db '> ',0
str3 db 'Connecting to ',0
str4 db 10,0
str5 db 'Name resolution failed.',10,10,0
str6 db 'A socket error occured.',10,10,0
str7 db 'A protocol error occured.',10,10,0
str8 db ' (',0
str9 db ')',10,0
str10 db 'Invalid hostname.',10,10,0
str11 db 10,'Remote host closed the connection.',10,10,0
sockaddr1:
dw AF_INET4
.port dw 0
.ip dd 0
rb 10
ssh_ident_ha:
dd_n (ssh_ident.length-2)
ssh_ident:
db "SSH-2.0-KolibriOS_SSH_0.01",13,10
.length = $ - ssh_ident
ssh_kex:
db SSH_MSG_KEXINIT
.cookie:
rd 4
.kex_algorithms:
dd_n .server_host_key_algorithms - .kex_algorithms - 4
db "diffie-hellman-group-exchange-sha256" ; diffie-hellman-group-exchange-sha1
.server_host_key_algorithms:
dd_n .encryption_algorithms_client_to_server - .server_host_key_algorithms - 4
db "ssh-rsa" ;,ssh-dss
.encryption_algorithms_client_to_server:
dd_n .encryption_algorithms_server_to_client - .encryption_algorithms_client_to_server - 4
db "aes256-cbc" ;,aes256-ctr,aes256-cbc,rijndael-cbc@lysator.liu.se,aes192-ctr,aes192-cbc,aes128-ctr,aes128-cbc,blowfish-ctr,blowfish-cbc,3des-ctr,3des-cbc,arcfour256,arcfour128"
.encryption_algorithms_server_to_client:
dd_n .mac_algorithms_client_to_server - .encryption_algorithms_server_to_client - 4
db "aes256-cbc" ;,aes256-ctr,aes256-cbc,rijndael-cbc@lysator.liu.se,aes192-ctr,aes192-cbc,aes128-ctr,aes128-cbc,blowfish-ctr,blowfish-cbc,3des-ctr,3des-cbc,arcfour256,arcfour128"
.mac_algorithms_client_to_server:
dd_n .mac_algorithms_server_to_client - .mac_algorithms_client_to_server - 4
db "hmac-sha2-256" ;,hmac-sha1,hmac-sha1-96,hmac-md5"
.mac_algorithms_server_to_client:
dd_n .compression_algorithms_client_to_server - .mac_algorithms_server_to_client - 4
db "hmac-sha2-256" ;,hmac-sha1,hmac-sha1-96,hmac-md5"
.compression_algorithms_client_to_server:
dd_n .compression_algorithms_server_to_client - .compression_algorithms_client_to_server - 4
db "none" ;,zlib"
.compression_algorithms_server_to_client:
dd_n .languages_client_to_server - .compression_algorithms_server_to_client - 4
db "none" ;,zlib"
.languages_client_to_server:
dd_n .languages_server_to_client - .languages_client_to_server - 4
db ""
.languages_server_to_client:
dd_n .first_kex_packet_follows - .languages_server_to_client - 4
db ""
.first_kex_packet_follows:
db 0
.reserved:
dd_n 0
.length = $ - ssh_kex
ssh_gex_req:
db SSH_MSG_KEX_DH_GEX_REQUEST
dd_n 128 ; DH GEX min
dd_n 256 ; DH GEX number of bits
dd_n 512 ; DH GEX Max
.length = $ - ssh_gex_req
ssh_new_keys:
db SSH_MSG_NEWKEYS
.length = $ - ssh_new_keys
include_debug_strings
; import
align 4
@IMPORT:
library network, 'network.obj', \
console, 'console.obj';, \
; libcrash, 'libcrash.obj'
import network, \
getaddrinfo, 'getaddrinfo', \
freeaddrinfo, 'freeaddrinfo', \
inet_ntoa, 'inet_ntoa'
import console, \
con_start, 'START', \
con_init, 'con_init', \
con_write_asciiz, 'con_write_asciiz', \
con_exit, 'con_exit', \
con_gets, 'con_gets', \
con_cls, 'con_cls', \
con_getch2, 'con_getch2', \
con_set_cursor_pos, 'con_set_cursor_pos', \
con_write_string, 'con_write_string', \
con_get_flags, 'con_get_flags'
;import libcrash, \
; crash.hash, 'crash_hash'
IncludeIGlobals
i_end:
decrypt_proc dd dummy_encrypt
encrypt_proc dd dummy_encrypt
rx_blocksize dd 4
tx_blocksize dd 4
rx_context dd ?
tx_context dd ?
IncludeUGlobals
socketnum dd ?
rx_packet_length dd ? ;;;;;
rx_buffer: rb BUFFERSIZE+1
tx_buffer: rb BUFFERSIZE+1
send_data dw ?
hostname rb 1024
; Diffie Hellman variables
dh_p dd ?
rb MAX_BITS/8
dh_g dd ?
rb MAX_BITS/8
dh_x dd ?
rb MAX_BITS/8
dh_e dd ?
rb MAX_BITS/8
dh_f dd ?
rb MAX_BITS/8
dh_signature dd ?
rb MAX_BITS/8
; Output from key exchange
dh_K dd ? ; Shared Secret (Big endian)
rb MAX_BITS/8
.length dd ? ; Length in little endian
dh_H rb 32 ; Exchange Hash
session_id rb 32
rx_iv rb 32 ; Rx initialisation vector
tx_iv rb 32 ; Tx initialisation vector
rx_enc_key rb 32 ; Rx encryption key
tx_enc_key rb 32 ; Tx encryption key
rx_int_key rb 32 ; Rx integrity key
tx_int_key rb 32 ; Tx integrity key
; Temporary values ; To be removed
mpint_tmp rb MPINT_MAX_LEN+4
mem: