luasec non block example based on luasec/sample/want (dont forget to generate certs from luasec/sample/certs!) start like this: $ lua server_ev.lua & $ lua client.lua & $ lua client.lua & $ lua handshake.lua &

client.lua

--
-- Test the conn:want() function
--
-- Public domain
--
require("socket")
require("ssl")

local params = {
   mode = "client",
   protocol = "sslv3",
   key = "../certs/clientAkey.pem",
   certificate = "../certs/clientA.pem",
   cafile = "../certs/rootA.pem",
   verify = {"peer", "fail_if_no_peer_cert"},
   options = {"all", "no_sslv2"},
}

-- Wait until socket is ready (for reading or writing)
local function wait(peer)
   -- What event blocked us?
   local err
   if peer.want then  -- Is it an SSL connection?
     err = peer:want()
     print("Want? ", err)
   else
     -- No, it's a normal TCP connection...
     err = "timeout"
   end

   if err == "read" or err == "timeout" then
      socket.select({peer}, nil)
   elseif err == "write" then
      socket.select(nil, {peer})
   else
      peer:close()
      os.exit(1)
   end
end

-- Start the TCP connection
local peer = socket.tcp()
assert( peer:connect("127.0.0.1", 8888) )

-- [[ SSL wrapper
peer = assert( ssl.wrap(peer, params) )
peer:settimeout(0.3)
local succ = peer:dohandshake()
while not succ do
   wait(peer)
   succ = peer:dohandshake()
end
print("** Handshake done")
--]]

-- If the section above is commented, the timeout is not set.
-- We set it again for safetiness.
peer:settimeout(0.3)

-- Try to receive a line
local str = peer:receive("*l")
while true do
   print(peer:receive("*l"))
   local n = math.random(1,100)
   if (n % 5) == 0 then
      print('reset',n)
      peer:send(tostring(n))
      if arg[1] then
         socket.sleep(2)
      end
      peer:send('\n')
   end
end
peer:close()

handshake.lua

--
-- Test the conn:want() function
--
-- Public domain
--
require("socket")
require("ssl")

local params = {
   mode = "client",
   protocol = "sslv3",
   key = "../certs/clientAkey.pem",
   certificate = "../certs/clientA.pem",
   cafile = "../certs/rootA.pem",
   verify = {"peer", "fail_if_no_peer_cert"},
   options = {"all", "no_sslv2"},
}

local function wait(peer)
   -- What event blocked us?
   local err
   if peer.want then  -- Is it an SSL connection?
     err = peer:want()
     socket.sleep(1)
     print("Want? ", err)
   else
     -- No, it's a normal TCP connection...
     err = "timeout"
   end

   if err == "read" or err == "timeout" then
      socket.select({peer}, nil)
   elseif err == "write" then
      socket.select(nil, {peer})
   else
      peer:close()
      os.exit(1)
   end
end

while true do

   -- Start the TCP connection
   local peer = socket.tcp()
   assert( peer:connect("127.0.0.1", 8888) )
   
   -- [[ SSL wrapper
   peer = assert( ssl.wrap(peer, params) )
   peer:settimeout(0)
   local succ = peer:dohandshake()
   while not succ do
      wait(peer)
      succ = peer:dohandshake()
   end
   print("** Handshake done")
   --]]

   print(peer:receive("*l"))
   peer:close()
end

server_ev.lua

--
-- Public domain
--
require("socket")
require("ssl")
local ev = require'ev'

local params = {
  mode = "server",
  protocol = "sslv3",
  key = "../certs/serverAkey.pem",
  certificate = "../certs/serverA.pem",
  cafile = "../certs/rootA.pem",
  verify = {"peer", "fail_if_no_peer_cert"},
  options = {"all", "no_sslv2"},
}

local ctx = assert(ssl.newcontext(params))

local server = socket.bind("127.0.0.1", 8888)
server:settimeout(0)
assert(server and server:getfd() > 0)
ev.IO.new(function()
    local peer = server:accept()
    local dispatch
    local retry
    peer:settimeout(0)
    peer = assert( ssl.wrap(peer, ctx) )
    peer:settimeout(0)
    local try_handshake = function(loop,watcher)
      watcher:stop(loop)
      local ok = peer:dohandshake()
      if ok then
        dispatch()
      else
        retry()
      end
    end
    retry = function()
      local want = peer:want()
      if want == 'read' then
        ev.IO.new(try_handshake,peer:getfd(),ev.READ):start(ev.Loop.default)
      elseif want == 'write' then
        ev.IO.new(try_handshake,peer:getfd(),ev.WRITE):start(ev.Loop.default)
      else
        assert(false,'should not happen')
      end
    end
    ev.Timer.new(try_handshake,0.0000001):start(ev.Loop.default)
    
    dispatch = function()
      local i = 0
      ev.Timer.new(function(loop,timer)
          i = i + 1
          timer:stop(loop)
          local last
          ev.IO.new(function(loop,io)
              local ok,err,last = peer:send(tostring(i)..'\n',last)
              if ok then
                io:stop(loop)
                timer:start(loop)
              elseif err == 'closed' then
                io:stop(loop)
              end
            end,peer:getfd(),ev.WRITE):start(loop)
          
        end,.01,.01):start(ev.Loop.default)
      
      local last
      ev.IO.new(function(loop,io)
          local line,err,part = peer:receive('*l')
          if part then
            last = (last or '')..part
          end
          if line then
            if last then
              line = last..line
              last = nil
            end
            local ok,new_i = pcall(tonumber,line)
            if ok then
              i = new_i
            end
          elseif err == 'closed' then
            io:stop(loop)
          end
        end,peer:getfd(),ev.READ):start(ev.Loop.default)
    end
  end,server:getfd(),ev.READ):start(ev.Loop.default)

ev.Loop.default:loop()