; ssh_userauth.inc - SSH user authentication
;
; Copyright (C) 2021 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/>.
proc sshlib_userauth_password con_ptr, username_sz, password_sz
; >> Request service (user-auth)
DEBUGF 2, "SSH: Requesting service\n"
stdcall sshlib_send_packet, [con_ptr], ssh_msg_request_service, ssh_msg_request_service.length, 0
cmp eax, 0
jl .err
; << Check for service acceptance
stdcall sshlib_msg_handler, [con_ptr], 0
cmp eax, 0
jl .err
mov eax, [con_ptr]
cmp [eax + sshlib_connection.rx_buffer.message_code], SSH_MSG_SERVICE_ACCEPT
jne .err_proto
; >> Request user authentication
DEBUGF 2, "SSH: User authentication\n"
mcall 68, 12, 1024 ; FIXME: hardcoded size
test eax, eax
jz .err_nomem
mov edi, eax
mov ebx, eax
mov byte[edi], SSH_MSG_USERAUTH_REQUEST
inc edi
; Insert username
stdcall sz_len, [username_sz]
mov ecx, eax
mov esi, [username_sz]
bswap eax
stosd
rep movsb
mov dword[edi], 0x0e000000 ; 14 Bswapped
mov dword[edi+4], "ssh-"
mov dword[edi+8], "conn"
mov dword[edi+12], "ecti"
mov word[edi+16], "on"
add edi, 18
mov dword[edi], 0x08000000 ; 8 Bswapped
mov dword[edi+4], "pass"
mov dword[edi+8], "word"
mov byte[edi+12], 0 ; bool
add edi, 13
; Insert password
stdcall sz_len, [password_sz]
mov ecx, eax
mov esi, [password_sz]
bswap eax
stosd
rep movsb
sub edi, ebx
push ebx
stdcall sshlib_send_packet, [con_ptr], ebx, edi, 0
; Clear used buffer and free
pop edx
mov edi, edx
push eax
mov ecx, 1024/4 ; FIXME
xor eax, eax
rep stosd
mcall 68, 13, edx
pop eax
cmp eax, 0
jl .err
; << Check for userauth acceptance
@@:
stdcall sshlib_msg_handler, [con_ptr], 0
cmp eax, 0
jl .err
mov eax, [con_ptr]
mov al, [eax + sshlib_connection.rx_buffer.message_code]
cmp al, SSH_MSG_USERAUTH_BANNER
je @r ; TODO
cmp al, SSH_MSG_USERAUTH_FAILURE
je .fail
cmp al, SSH_MSG_USERAUTH_SUCCESS
jne .err_proto
xor eax, eax
.err:
ret
.fail:
xor eax, eax
inc eax
ret
.err_proto:
mov eax, SSHLIB_ERR_PROTOCOL
ret
.err_nomem:
mov eax, SSHLIB_ERR_NOMEM
ret
endp
; Actually, string is \n and/or \0 terminated 0_o
proc sz_len uses ecx edi, string
mov edi, [string]
mov ecx, 256 ;;;;
mov al, 10
repne scasb
dec edi
sub edi, [string]
mov eax, edi
ret
endp