Fix #2852: add TLS support to redis.lua, better detection with -sV

nselib/redis.lua

@@ -6,6 +6,7 @@ local match = require "match"
 local nmap = require "nmap"
 local stdnse = require "stdnse"
 local table = require "table"
+local comm = require "comm"
 _ENV = stdnse.module("redis", stdnse.seeall)
 
 Request = {
@@ -30,6 +31,63 @@ Request = {
 
 }
 
+local socket_wrapper = {
+  new = function(self, socket, init)
+    local o = {
+      socket = socket,
+      init = init,
+      pos = init and 1 or nil,
+    }
+    setmetatable (o,self)
+    self.__index = self
+    return o
+  end,
+
+  getline = function(self)
+    if self.pos then
+      local oldpos = self.pos
+      local first, last = self.init:find("\r\n", oldpos)
+      if first then
+        stdnse.debug1("getline: found line: %s", self.init:sub(oldpos, first-1))
+        self.pos = last < #self.init and (last + 1) or nil
+        return true, self.init:sub(oldpos, first-1)
+      else
+        stdnse.debug1("getline: no line found: %s", self.init:sub(oldpos))
+        self.pos = nil
+        local status, more = self.socket:receive_buf(match.pattern_limit("\r\n", 2048), false)
+        if not status then
+          return status, more
+        end
+        return true, self.init:sub(oldpos) .. more
+      end
+    end
+    return self.socket:receive_buf(match.pattern_limit("\r\n", 2048), false)
+  end,
+
+  getbytes = function(self, len)
+    if self.pos then
+      local remains = #self.init - self.pos + 1
+      stdnse.debug1("getbytes(%d), remains=%d", len, remains)
+      if remains == len then
+        self.pos = nil
+        return true, self.init:sub(-len)
+      elseif remains > len then
+        local part = self.init:sub(self.pos, self.pos + len - 1)
+        self.pos = self.pos + len
+        return true, part
+      else
+        local part = self.init:sub(self.pos)
+        self.pos = nil
+        local status, more = self.socket:receive_buf(match.numbytes(len - #part), false)
+        if not status then
+          return status, more
+        end
+        return true, part .. more
+      end
+    end
+    return self.socket:receive_buf(match.numbytes(len), true)
+  end,
+}
 
 Response = {
 
@@ -48,8 +106,10 @@ Response = {
     return o
   end,
 
-  receive = function(self)
-    local status, data = self.socket:receive_buf(match.pattern_limit("\r\n", 2048), false)
+  receive = function(self, init)
+    stdnse.debug1("Response.receive(%d)", #(init or ""))
+    local sock = socket_wrapper:new(self.socket, init)
+    local status, data = sock:getline()
     if ( not(status) ) then
       return false, "Failed to receive data from server"
     end
@@ -78,12 +138,12 @@ Response = {
 
       local len = tonumber(data:match("^%$(%d*)"))
       -- we should only have a single line, so we can just peel of the length
-      status, data = self.socket:receive_buf(match.numbytes(len), true)
+      status, data = sock:getbytes(len)
       if( not(status) ) then
         return false, "Failed to receive data from server"
       end
       -- move past the terminal CRLF
-      local status, crlf = self.socket:receive_buf(match.pattern_limit("\r\n", 2048), false)
+      local status, crlf = sock:getline()
 
       return true, { data = data, type = Response.Type.BULK }
     end
@@ -95,12 +155,12 @@ Response = {
 
       for i=1, count do
         -- peel of the length
-        local status = self.socket:receive_buf(match.pattern_limit("\r\n", 2048), false)
+        local status = sock:getline()
         if( not(status) ) then
           return false, "Failed to receive data from server"
         end
 
-        status, data = self.socket:receive_buf(match.pattern_limit("\r\n", 2048), false)
+        status, data = sock:getline()
         if( not(status) ) then
           return false, "Failed to receive data from server"
         end
@@ -125,18 +185,27 @@ Helper = {
     return o
   end,
 
-  connect = function(self, socket)
-    self.socket = socket or nmap.new_socket()
-    return self.socket:connect(self.host, self.port)
+  connect = function(self)
+    return true
+  end,
+
+  do_send = function(self, payload)
+    local response
+    if not self.socket then
+      self.socket, response = comm.tryssl(self.host, self.port, payload)
+      return not not self.socket, response
+    else
+      return self.socket:send(payload)
+    end
   end,
 
   reqCmd = function(self, cmd, ...)
     local req = Request:new(cmd, ...)
-    local status, err = self.socket:send(tostring(req))
+    local status, err_or_response = self:do_send(tostring(req))
     if (not(status)) then
       return false, "Failed to send command to server"
     end
-    return Response:new(self.socket):receive()
+    return Response:new(self.socket):receive(err_or_response)
   end,
 
   close = function(self)