Still work to do in the manual...

src/ltn12.lua

@@ -23,6 +23,7 @@ BLOCKSIZE = 2048
 -----------------------------------------------------------------------------
 -- returns a high level filter that cycles a low-level filter
 function filter.cycle(low, ctx, extra)
+    assert(low)
     return function(chunk)
         local ret
         ret, ctx = low(ctx, chunk, extra)
@@ -32,6 +33,7 @@ end
 
 -- chains two filters together
 local function chain2(f1, f2)
+    assert(f1 and f2)
     local co = coroutine.create(function(chunk)
         while true do
             local filtered1 = f1(chunk)
@@ -95,6 +97,7 @@ end
 
 -- turns a fancy source into a simple source
 function source.simplify(src)
+    assert(src)
     return function()
         local chunk, err_or_new = src()
         src = err_or_new or src
@@ -118,6 +121,7 @@ end
 
 -- creates rewindable source
 function source.rewind(src)
+    assert(src)
     local t = {}
     return function(chunk)
         if not chunk then
@@ -132,6 +136,7 @@ end
 
 -- chains a source with a filter
 function source.chain(src, f)
+    assert(src and f)
     local co = coroutine.create(function()
         while true do 
             local chunk, err = src()
@@ -186,6 +191,7 @@ end
 
 -- turns a fancy sink into a simple sink
 function sink.simplify(snk)
+    assert(snk)
     return function(chunk, err)
         local ret, err_or_new = snk(chunk, err)
         if not ret then return nil, err_or_new end
@@ -224,6 +230,7 @@ end
 
 -- chains a sink with a filter 
 function sink.chain(f, snk)
+    assert(f and snk)
     return function(chunk, err)
         local filtered = f(chunk)
         local done = chunk and ""
@@ -248,6 +255,7 @@ end
 
 -- pumps all data from a source to a sink, using a step function
 function pump.all(src, snk, step)
+    assert(src and snk)
     step = step or pump.step
     while true do
         local ret, err = step(src, snk)

src/smtp.lua

@@ -11,6 +11,7 @@
 local smtp = requirelib("smtp", "luaopen_smtp", getfenv(1))
 local socket = require("socket")
 local ltn12 = require("ltn12")
+local mime = require("mime")
 local tp = require("tp")
 
 -----------------------------------------------------------------------------
@@ -43,7 +44,7 @@ local metat = { __index = {} }
 function metat.__index:greet(domain)
     socket.try(self.tp:check("2.."))
     socket.try(self.tp:command("EHLO", domain or DOMAIN))
-    return socket.try(self.tp:check("2.."))
+    return socket.skip(1, socket.try(self.tp:check("2..")))
 end 
 
 function metat.__index:mail(from)
@@ -73,6 +74,32 @@ function metat.__index:close()
     return socket.try(self.tp:close())
 end
 
+function metat.__index:login(user, password)
+    socket.try(self.tp:command("AUTH", "LOGIN"))
+    socket.try(self.tp:check("3.."))
+    socket.try(self.tp:command(mime.b64(user)))
+    socket.try(self.tp:check("3.."))
+    socket.try(self.tp:command(mime.b64(password)))
+    return socket.try(self.tp:check("2.."))
+end
+
+function metat.__index:plain(user, password)
+    local auth = "PLAIN " .. mime.b64("\0" .. user .. "\0" .. password)
+    socket.try(self.tp:command("AUTH", auth))
+    return socket.try(self.tp:check("2.."))
+end
+
+function metat.__index:auth(user, password, ext)
+    if not user or not password then return 1 end
+    if string.find(ext, "AUTH[^\n]+LOGIN") then
+        return self:login(user, password)
+    elseif string.find(ext, "AUTH[^\n]+PLAIN") then
+        return self:plain(user, password)
+    else
+        socket.try(nil, "authentication not supported")
+    end
+end
+
 -- send message or throw an exception
 function metat.__index:send(mailt) 
     self:mail(mailt.from)
@@ -205,10 +232,10 @@ end
 ---------------------------------------------------------------------------
 -- High level SMTP API
 -----------------------------------------------------------------------------
-socket.protect = function(a) return a end
 send = socket.protect(function(mailt)
     local con = open(mailt.server, mailt.port)
-    con:greet(mailt.domain)
+    local ext = con:greet(mailt.domain)
+    con:auth(mailt.user, mailt.password, ext)
     con:send(mailt)
     con:quit()
     return con:close()