From e28247b8975b88dd8f82db30eb9be83def201f71 Mon Sep 17 00:00:00 2001
From: doesnm <doesnm@0ut0f.space>
Date: Tue, 23 Jan 2024 19:36:48 +0100
Subject: [PATCH] Upload files to "/"

---
 mail.lua | 124 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 124 insertions(+)
 create mode 100644 mail.lua

diff --git a/mail.lua b/mail.lua
new file mode 100644
index 0000000..6651386
--- /dev/null
+++ b/mail.lua
@@ -0,0 +1,124 @@
+
+function mysplit (inputstr, sep)
+        if sep == nil then
+                sep = "%s"
+        end
+        local t={}
+        for str in string.gmatch(inputstr, "([^"..sep.."]+)") do
+                table.insert(t, str)
+        end
+        return t
+end
+
+
+function table.slice(tbl, first, last, step)
+  local sliced = {}
+
+  for i = first or 1, last or #tbl, step or 1 do
+    sliced[#sliced+1] = tbl[i]
+  end
+
+  return sliced
+end
+
+
+function validate(data,from,to)
+headers = {}
+begindata = false
+i = 1
+while true do
+  line = mysplit(data,"\n")[i]
+  if line == nil then break end
+  if begindata == false then
+  line = mysplit(line, ":")
+if line[1] == nil then
+  begindata = true
+  else
+headers[line[1]] = line[2]
+  end
+  
+  else
+  headers["body"] = (headers["body"] or "") .. line .. "\n"
+  end
+  i = i + 1
+end
+if not headers["From"] or not headers["From"]:find(from) then return false end
+if not to:find("@doesnm.cc") then return false end
+return headers
+end
+
+function string.starts(String,Start)
+   return string.sub(String,1,string.len(Start))==Start
+end
+
+from = nil
+to = nil
+data = false
+dataBuf = ""
+print("220 doesnm.cc Simple Mail Transfer Service Ready")
+
+while true do
+  line = io.read("*line")
+  line = mysplit(line)
+  if line[1] == "NOOP" and data == false then
+    print("250 OK")
+  elseif line[1] == "HELO" then
+    if #line < 2 then
+    print("251 Command requires argument")
+    else
+    print("250 Hello " .. line[2])
+    end
+  elseif line[1] == "EHLO" then
+    if #line < 2 then
+    print("251 Command requires argument")
+    else
+    print("250-Hello " .. line[2])
+    print("250 SIZE 1000000")
+    end
+  elseif line[1] == "VRFY" and data == false then
+    print("252 Cannot VRFY user, but will accept message")
+  elseif line[1] == "QUIT" and data == false then
+    print("221 Bye!")
+    os.exit()
+  elseif line[1] == "MAIL" and data == false then
+    if #line < 2 then print("501 Incorrent number of arguments")
+    else
+    if string.starts(line[2],"FROM:") then
+      from = table.concat(table.slice(mysplit(table.concat(line," "),":"),2))
+      print("250 OK")
+    else
+      print("501 Incorrect number of arguments")
+    end
+    end
+  elseif line[1] == "RCPT" and data == false then
+    if #line < 2 then
+      print("501 Incorrent number of arguments")
+    else
+    if string.starts(line[2],"TO:") then
+to = table.concat(table.slice(mysplit(table.concat(line," "),":"),2))
+      print("250 OK")
+    else
+      print("502 Unrecognized command")
+    end
+    end
+  elseif line[1] == "DATA" and from ~= nil and to ~= nil then
+    data = true
+    print("354 Send message content; End with <CRLF>.<CRLF>")
+  elseif line[1] == "." and data == true then
+    if not validate(dataBuf,from,to) then print("250 NOTOK")
+      data = false else
+    out = io.open("/var/mail/root","a")
+    out:write("From " .. from .." ".. os.date("%a %b %d %H:%M:%S %Y") .. "\n")
+    out:write(dataBuf)
+    out:close()
+    print("250 OK")
+    data = false
+    end
+  else
+    if data == true then
+      dataBuf = dataBuf .. table.concat(line, " ") .. "\n"
+    else
+    print("502 Unrecognized command")
+    end
+  end
+end
\ No newline at end of file