1 files changed, 175 insertions, 0 deletions
diff --git a/nselib/rsync.lua b/nselib/rsync.lua
new file mode 100644
index 0000000..f477524
--- /dev/null
+++ b/nselib/rsync.lua
@@ -0,0 +1,175 @@
+---
+-- A minimalist RSYNC (remote file sync) library
+--
+-- @author Patrik Karlsson <patrik@cqure.net>
+
+local base64 = require "base64"
+local match = require "match"
+local nmap = require "nmap"
+local stdnse = require "stdnse"
+local string = require "string"
+local table = require "table"
+local openssl = stdnse.silent_require "openssl"
+_ENV = stdnse.module("rsync", stdnse.seeall)
+
+
+-- The Helper class serves as the main interface for script writers
+Helper = {
+
+  -- Creates a new instance of the Helper class
+  -- @param host table as received by the action function
+  -- @param port table as received by the action function
+  -- @param options table containing any additional options
+  -- @return o instance of Helper
+  new = function(self, host, port, options)
+    local o = { host = host, port = port, options = options or {} }
+    assert(o.options.module, "No rsync module was specified, aborting ...")
+    setmetatable(o, self)
+    self.__index = self
+    return o
+  end,
+
+  -- Handles send and receive of control messages
+  -- @param data string containing the command to send
+  -- @return status true on success, false on failure
+  -- @return data containing the response from the server
+  --         err string, if status is false
+  ctrl_exch = function(self, data)
+    local status, err = self.socket:send(data.."\n")
+    if ( not(status) ) then
+      return false, err
+    end
+    local status, data = self.socket:receive_buf(match.pattern_limit("\n", 2048), false)
+    if( not(status) ) then
+      return false, err
+    end
+    return true, data
+  end,
+
+  -- Connects to the rsync server
+  -- @return status, true on success, false on failure
+  -- @return err string containing an error message if status is false
+  connect = function(self, socket)
+    self.socket = socket or nmap.new_socket()
+    self.socket:set_timeout(self.options.timeout or 5000)
+    local status, err = self.socket:connect(self.host, self.port)
+    if ( not(status) ) then
+      return false, err
+    end
+
+    local data
+    status, data = self:ctrl_exch("@RSYNCD: 29")
+    if ( not(status) ) then
+      return false, data
+    end
+    if ( not(data:match("^@RSYNCD: [%.%d]+$")) ) then
+      return false, "Protocol error"
+    end
+    return true
+  end,
+
+  -- Authenticates against the rsync module. If no username is given, assume
+  -- no authentication is required.
+  -- @param username [optional] string containing the username
+  -- @param password [optional] string containing the password
+  login = function(self, username, password)
+    password = password or ""
+    local status, data = self:ctrl_exch(self.options.module)
+    if (not(status)) then
+      return false, data
+    end
+
+    local chall
+    if ( data:match("@RSYNCD: OK") ) then
+      return true, "No authentication was required"
+    else
+      chall = data:match("^@RSYNCD: AUTHREQD (.*)$")
+      if ( not(chall) and data:match("^@ERROR: Unknown module") ) then
+        return false, data:match("^@ERROR: (.*)$")
+      elseif ( not(chall) ) then
+        return false, "Failed to retrieve challenge"
+      end
+    end
+
+    if ( chall and not(username) ) then
+      return false, "Authentication required"
+    end
+
+    local md4 = openssl.md4("\0\0\0\0" .. password .. chall)
+    local resp = base64.enc(md4):sub(1,-3)
+    status, data = self:ctrl_exch(username .. " " .. resp)
+    if (not(status)) then
+      return false, data
+    end
+
+    if ( data == "@RSYNCD: OK" ) then
+      return true, "Authentication successful"
+    end
+    return false, "Authentication failed"
+  end,
+
+  -- Lists accessible modules from the rsync server
+  -- @return status true on success, false on failure
+  -- @return modules table containing a list of modules
+  listModules = function(self)
+    local status, data = self.socket:send("\n")
+    if (not(status)) then
+      return false, data
+    end
+
+    local modules = {}
+    while(true) do
+      status, data = self.socket:receive_buf(match.pattern_limit("\n", 2048), false)
+      if (not(status)) then
+        return false, data
+      end
+      if ( data == "@RSYNCD: EXIT" ) then
+        break
+      else
+        table.insert(modules, data)
+      end
+    end
+    return true, modules
+  end,
+
+  -- Lists the files available for the directory/module
+  -- TODO: Add support for parsing results, seemed straight forward at
+  --       first, but wasn't.
+  listFiles = function(self)
+    -- list recursively and enable MD4 checksums
+    local data = ("--server\n--sender\n-rc\n.\n%s\n\n"):format(self.options.module)
+    local status, data = self.socket:send(data)
+    if ( not(status) ) then
+      return false, data
+    end
+    status, data = self.socket:receive_bytes(4)
+    if ( not(status) ) then
+      return false, data
+    end
+
+    status, data = self.socket:send("\0\0\0\0")
+    if ( not(status) ) then
+      return false, data
+    end
+
+    status, data = self.socket:receive_buf(match.numbytes(4), true)
+    if ( not(status) ) then
+      return false, data
+    end
+
+    local len = string.unpack("<I2", data)
+    status, data = self.socket:receive_buf(match.numbytes(len), true)
+    if ( not(status) ) then
+      return false, data
+    end
+
+    -- Parsing goes here
+  end,
+
+  -- Disconnects from the rsync server
+  -- @return status true on success, false on failure
+  disconnect = function(self) return self.socket:close() end,
+
+}
+
+return _ENV;