section .data
banner_str db `SPED - the stupidly pointless editor\n`, 0x00
nofile_str db `no file provided\n`, 0x00
+ readlines_str db `opened file with %i lines\n`, 0x00
prompt_str db `sped > `, 0x00
- invalidcommand_str db `invalid command\n`, 0x00
+ invalidcmd_str db `invalid command\n`, 0x00
+ invalidaddr_str db `invalid address\n`, 0x00
charcount_str db `read %i chars\n`, 0x00
+ currentline_str db `current line: %i\n`, 0x00
+ echo_str db `%s`, 0x00 ; print strings without format exploit
section .bss
buffer resb 4
call readFile
mov [buffer], eax
- mov [buffer_lines], ebx
+ mov [buffer_lines], ecx
mov DWORD [cur_line], 0x00
+ push DWORD [buffer_lines]
+ push readlines_str
+ call printf
+
call repl
mov eax, 0
; commands are single char for now
cmp ecx, 1
- jne _repl_invalid
+ jne _repl_invalid_cmd
; parse commands
mov eax, DWORD [ebp-CMDSTR]
jmp _repl_exit
_repl_cmd_quit_end:
+ ; p prints current line
+ mov eax, DWORD [ebp-CMDSTR]
+ cmp BYTE [eax], 'p'
+ jne _repl_cmd_print_end
+
+ mov eax, DWORD [cur_line]
+ mov ecx, 4
+ mul ecx
+ add eax, [buffer]
+ push DWORD [eax]
+ push echo_str
+ call printf
+ jmp _repl_continue
+ _repl_cmd_print_end:
+
+ ; n prints the current line number
+ mov eax, DWORD [ebp-CMDSTR]
+ cmp BYTE [eax], 'n'
+ jne _repl_cmd_number_end
+
+ push DWORD [cur_line]
+ push currentline_str
+ call printf
+
+ jmp _repl_continue
+ _repl_cmd_number_end:
+
+ ; - goes to prev line
+ mov eax, DWORD [ebp-CMDSTR]
+ cmp BYTE [eax], '-'
+ jne _repl_cmd_decline_end
+
+ ; make sure we are within bounds
+ mov eax, DWORD [cur_line]
+ sub eax, 1
+ cmp eax, 0
+ jl _repl_invalid_addr
+
+ sub DWORD [cur_line], 1
+
+ jmp _repl_continue
+ _repl_cmd_decline_end:
+
+ ; + goes to next line
+ mov eax, DWORD [ebp-CMDSTR]
+ cmp BYTE [eax], '+'
+ jne _repl_cmd_incline_end
+
+ ; make sure we are within bounds
+ mov eax, DWORD [cur_line]
+ add eax, 1
+ cmp eax, [buffer_lines]
+ jge _repl_invalid_addr
+
+ add DWORD [cur_line], 1
+
+ jmp _repl_continue
+ _repl_cmd_incline_end:
+
+
+ jmp _repl_invalid_cmd
+
+ ; some error messages
+ _repl_invalid_cmd:
+ push invalidcmd_str
+ call printf
+ jmp _repl_continue
- _repl_invalid:
- push invalidcommand_str
+ _repl_invalid_addr:
+ push invalidaddr_str
call printf
+ jmp _repl_continue
_repl_continue:
jmp _repl_loop