---
-- DRDA Library supporting a very limited subset of operations.
--
-- Summary
-- * The library currently provides functionality to: (1) Query the server for
-- basic settings using the <code>getServerInfo</code> function of the helper
-- class. (2) Authenticate to a DB2 server using a plain-text username and
-- password.
--
-- The library contains the following classes:
-- * <code>DRDA</code>
-- ** Implements the Distributed Relational Database Architecture class .
-- * <code>DRDAParameter</code>
-- ** Implements a number of functions to handle DRDA parameters.
-- * <code>DDM</code>
-- ** Implements the DDM portion of the DRDA structure
-- * <code>Command</code>
-- ** Provides functions for easy creation of the most common DRDAs.
-- ** Implemented as a static class that returns an instance of the DRDA.
-- * <code>Helper</code>
-- ** A helper class that provides easy access to the rest of the library
-- * <code>DB2Socket</code>
-- ** A smallish socket wrapper that provides fundamental buffering
-- * <code>StringUtil</code>
-- ** Provides EBCDIC/ASCII conversion functions
-- * <code>Comm</code>
-- ** Provides fundamental communication support (send/receive DRDAPacket)
-- * <code>DRDAPacket</code>
-- ** A class holding one or more DRDA's and provides some basic access methods
--
-- The following sample code illustrates how scripts can use the Helper class
-- to interface with the library:
--
-- <code>
-- db2helper = drda.Helper:new()
-- status, err = db2helper:connect(host, port)
-- status, res = db2helper:getServerInfo()
-- status, err = db2helper:close()
-- </code>
--
-- The implementation is based on packet dumps and the excellent decoding
-- provided by Wireshark.
--
-- There is some documentation at
-- http://publib.boulder.ibm.com/infocenter/dzichelp/v2r2/topic/com.ibm.db29.doc.drda/db2z_drda.htm.
--
-- @copyright Same as Nmap--See http://nmap.org/book/man-legal.html
-- @author "Patrik Karlsson <patrik@cqure.net>"
--
--
-- Version 0.2
-- Created 05/08/2010 - v0.1 - created by Patrik Karlsson <patrik@cqure.net>
-- Revised 07/27/2010 - v0.2 - Added the comm class and made a few improvements
-- to sending and receiving packets. Changed the
-- helper login method to support:
-- x IBM DB2
-- x Apache Derby
-- x IBM Informix Dynamic Server
local bin = require "bin"
local bit = require "bit"
local match = require "match"
local nmap = require "nmap"
local stdnse = require "stdnse"
local string = require "string"
local table = require "table"
_ENV = stdnse.module("drda", stdnse.seeall)
-- CodePoint constants
CodePoint = {
CODEPNT = 0x000c,
TYPDEFNAM = 0x002f,
TYPDEFOVR = 0x0035,
ACCSEC = 0x106d,
SECCHK = 0x106e,
EXCSAT = 0x1041,
PRDID = 0x112e,
SRVCLSNM = 0x1147,
SVRCOD = 0x1149,
SYNERRCD = 0x114a,
SRVRLSLV = 0x115a,
EXTNAM = 0x115e,
SRVNAM = 0x116d,
USRID = 0x11a0,
PASSWORD = 0x11a1,
SECMEC = 0x11a2,
SECCHKCD = 0x11a4,
SECCHKRM = 0x1219,
SYNTAXRM = 0x124c,
MGRLVLLS = 0x1404,
EXCSATRD = 0x1443,
ACCSECRD = 0x14ac,
ACCRDB = 0x2001,
PRDDATA = 0x2104,
RDBACCL = 0x210f,
RDBNAM = 0x2110,
CRRTKN = 0x2135,
ACCRDBRM = 0x2201,
RDBNFNRM = 0x2211,
RDBAFLRM = 0x221a,
RDBATHRM = 0x22cb,
}
-- Security Mechanism
SecMec =
{
USER_PASSWORD = 0x0003,
USER_ONLY = 0x0004,
CHANGE_PASSWORD = 0x0005,
USER_PASS_SUBST = 0x0006,
USER_ENC_PASS = 0x0007,
ENC_USER_ENC_PASS = 0x0009,
ENC_CHANGE_PASS = 0x000A,
KERBEROS = 0x000B,
ENC_USER_DATA = 0x000C,
ENC_USER_ENC_PASS_ENC_DATA = 0x000D,
ENC_USER_ENC_PASS_ENC_NEWPASS_ENC_DATA = 0x000E,
}
DRDAPacket = {
new = function(self, drda_array)
local o = {
drda_array = drda_array,
count = #drda_array
}
setmetatable(o, self)
self.__index = self
return o
end,
getDRDAByCodePoint = function( self, codepoint )
for i=1, #self.drda_array do
if ( self.drda_array[i].DDM.CodePoint == codepoint ) then
return self.drda_array[i]
end
end
end,
getDRDA = function( self, n )
return ( #self.drda_array >= n ) and self.drda_array[n] or nil
end,
__tostring = function( self )
local data = ""
-- do some DDM fixup in here
for i=1, #self.drda_array do
if ( i == 1 and #self.drda_array > 1 ) then
self.drda_array[1].DDM.Format = 0x41
else
self.drda_array[i].DDM.Format = 0x01
end
self.drda_array[i].DDM.CorelId = i
data = data .. tostring(self.drda_array[i])
end
return data
end
}
-- Distributed Relational Database Architecture (DRDA) Class
DRDA = {
new = function(self, ddm)
local o = {
Parameters = {},
DDM = ddm
}
setmetatable(o, self)
self.__index = self
return o
end,
--- Sets the DDM
--
-- @param ddm DDM to assign to the DRDA
-- @return status boolean true on success, false on failure
setDDM = function( self, ddm )
if ( not(ddm) ) then
return false, "DDM cannot be nil"
end
self.DDM = ddm
return true
end,
--- Adds a DRDA parameter to the table
--
-- @param param DRDAParam containing the parameter to add to the table
-- @return status bool true on success, false on failure
-- @return err string containing the error message if status is false
addParameter = function( self, param )
if ( not(self.DDM) ) then
stdnse.print_debug("drda.DRDA.addParameter: DDM must be set prior to adding parameters")
return false, "DDM must be set prior to adding parameters"
end
if ( not(param) ) then
stdnse.print_debug("drda.DRDA.addParameter: Param cannot be nil")
return false, "Param cannot be nil"
end
table.insert(self.Parameters, param)
-- update the DDM length fields
self.DDM.Length = self.DDM.Length + param.Length
self.DDM.Length2 = self.DDM.Length2 + param.Length
return true
end,
--- Gets a parameter from the DRDA parameter table
--
-- @param codepoint number containing the parameter type ro retrieve
-- @return param DRDAParameter containing the requested parameter
getParameter = function( self, codepoint )
for _, v in ipairs( self.Parameters ) do
if ( v.CodePoint == codepoint ) then
return v
end
end
return
end,
--- Converts the DRDA class to a string
--
-- @return data containing the object instance
__tostring = function(self)
if ( not(self.DDM) ) then
stdnse.print_debug("drda.DRDA.toString: DDM cannot be nil")
return nil
end
local data = bin.pack(">SCCSSS", self.DDM.Length, self.DDM.Magic, self.DDM.Format, self.DDM.CorelId, self.DDM.Length2, self.DDM.CodePoint )
for k,v in ipairs(self.Parameters) do
data = data .. tostring(v)
end
return data
end,
--- Sends the DRDA over the db2socket
--
-- @param db2socket DB2Socket over which to send the data
-- @return Status (true or false).
-- @return Error code (if status is false).
send = function( self, db2socket )
return db2socket:send( tostring(self) )
end,
--- Receives data from the db2socket and builds a DRDA object
--
-- @param db2socket from which to read data
-- @return Status (true or false).
-- @return Data (if status is true) or error string (if status is false).
receive = function( self, db2socket )
local DDM_SIZE = 10
local pos = 1
-- first read atleast enough so that we can populate the DDM
local status, data = db2socket:receive_buf( match.numbytes(DDM_SIZE), true )
if ( not(status) ) then
stdnse.print_debug("drda.DRDA.receive: %s", data)
return false, ("Failed to read at least %d bytes from socket"):format(DDM_SIZE)
end
local ddm = DDM:new()
ddm:fromString( data )
self:setDDM( ddm )
status, data = db2socket:receive_buf( match.numbytes(ddm.Length - 10), true )
if ( not(status) ) then
return false, ("Failed to read the remaining %d bytes of the DRDA message")
end
-- add parameters until pos reaches the "end"
repeat
local param = DRDAParameter:new()
pos = param:fromString( data, pos )
self:addParameter( param )
until ( #data <= pos )
return true
end,
}
-- The DRDAParameter class implements the DRDA parameters
DRDAParameter = {
--- DRDA Parameter constructor
--
-- @param codepoint number containing the codepoint value
-- @param data string containing the data portion of the DRDA parameter
-- @return o DRDAParameter object
new = function(self, codepoint, data)
local o = {
CodePoint = codepoint,
Data = data,
Length = ( data and #data + 4 or 4 )
}
setmetatable(o, self)
self.__index = self
return o
end,
--- Converts the DRDA Parameter object to a string
--
-- @return data string containing the DRDA Parameter
__tostring = function( self )
local data = bin.pack(">SS", self.Length, self.CodePoint )
if ( self.Data ) then
data = data .. bin.pack("A", self.Data)
end
return data
end,
--- Builds a DRDA Parameter from a string
--
-- @param data string from which to build the DRDA Parameter
-- @param pos number containing the offset into data
-- @return pos the new position after processing, -1 on error
fromString = function( self, data, pos )
if( #data < 4 ) then
return -1
end
pos, self.Length, self.CodePoint = bin.unpack( ">SS", data, pos )
-- make sure the Length is assigned a value even though 0(nil) is returned
self.Length = self.Length or 0
if ( self.Length > 0 ) then
pos, self.Data = bin.unpack("A" .. self.Length - 4, data, pos )
end
return pos
end,
--- Returns the data portion of the parameter as an ASCII string
--
-- @return str containing the data portion of the DRDA parameter as ASCII
getDataAsASCII = function( self )
return StringUtil.toASCII( self.Data )
end,
--- Returns the data in EBCDIC format
--
-- @return str containing the data portion of the DRDA parameter in EBCDIC
getData = function( self )
return self.Data
end,
}
-- Distributed data management (DDM)
DDM = {
Formats =
{
RESERVED = 0x80,
CHAINED = 0x40,
CONTINUE = 0x20,
SAME_CORRELATION = 0x10,
},
Length = 10,
Magic = 0xD0,
Format = 0x41,
CorelId = 1,
Length2 = 4,
CodePoint = 0,
--- Creates a new DDM packet
--
-- @param codepoint
-- @param format
-- @param corelid
-- @return DDM object
new = function(self, codepoint, format, corelid)
local o = {
CodePoint = codepoint,
Format = format,
CorelId = corelid
}
setmetatable(o, self)
self.__index = self
return o
end,
--- Converts the DDM object to a string
__tostring = function( self )
return bin.pack(">SCCSSS", self.Length, self.Magic, self.Format, self.CorelId, self.Length2, self.CodePoint)
end,
--- Constructs a DDM object from a string
--
-- @param str containing the data from which to construct the object
fromString = function( self, str )
local DDM_SIZE = 10
local pos = 1
if ( #str < DDM_SIZE ) then
return -1, ("drda.DDM.fromString: str was less than DDM_SIZE (%d)"):format( DDM_SIZE )
end
pos, self.Length, self.Magic, self.Format, self.CorelId, self.Length2, self.CodePoint = bin.unpack( ">SCCSSS", str )
return pos
end,
--- Verifiers if there are additional DRDA's following
--
-- @return true if the DRDA is to be chained, false if it's the last one
isChained = function( self )
if ( bit.band( self.Format, DDM.Formats.CHAINED ) == DDM.Formats.CHAINED ) then
return true
end
return false
end,
--- Set the DRDA as chained (more following)
--
-- @param chained boolean true if more DRDA's are following
setChained = function( self, chained )
if ( self:isChained() ) then
self.Format = bit.bxor( self.Format, self.Formats.CHAINED )
else
self.Format = bit.bor( self.Format, self.Formats.CHAINED )
end
end,
}
-- static DRDA packet construction class
Command =
{
--- Builds an EXCSAT DRDA packet
--
-- @param extname string containing the external name
-- @param srvname string containing the server name
-- @param rellev string containing the server product release level
-- @param mgrlvlls string containing the manager level list
-- @param srvclass string containing the server class name
-- @return drda DRDA instance
EXCSAT = function( extname, srvname, rellev, mgrlvlls, srvclass )
local drda = DRDA:new( DDM:new( CodePoint.EXCSAT ) )
drda:addParameter( DRDAParameter:new( CodePoint.EXTNAM, StringUtil.toEBCDIC( extname ) ) )
drda:addParameter( DRDAParameter:new( CodePoint.SRVNAM, StringUtil.toEBCDIC( srvname ) ) )
drda:addParameter( DRDAParameter:new( CodePoint.SRVRLSLV, StringUtil.toEBCDIC( rellev ) ) )
drda:addParameter( DRDAParameter:new( CodePoint.MGRLVLLS, mgrlvlls ) )
drda:addParameter( DRDAParameter:new( CodePoint.SRVCLSNM, StringUtil.toEBCDIC( srvclass ) ) )
return drda
end,
--- Builds an ACCSEC DRDA packet
--
-- @param secmec number containing the security mechanism ID
-- @param database string containing the database name
-- @return drda DRDA instance
ACCSEC = function( secmec, database )
local drda = DRDA:new( DDM:new( CodePoint.ACCSEC ) )
drda:addParameter( DRDAParameter:new( CodePoint.SECMEC, secmec ))
drda:addParameter( DRDAParameter:new( CodePoint.RDBNAM, StringUtil.toEBCDIC(StringUtil.padWithChar(database,' ', 18)) ))
return drda
end,
--- Builds a SECCHK DRDA packet
--
-- @param secmec number containing the security mechanism ID
-- @param database string containing the database name
-- @param username string
-- @param password string
-- @return drda DRDA instance
SECCHK = function( secmec, database, username, password )
local drda = DRDA:new( DDM:new( CodePoint.SECCHK ) )
drda:addParameter( DRDAParameter:new( CodePoint.SECMEC, secmec ))
drda:addParameter( DRDAParameter:new( CodePoint.RDBNAM, StringUtil.toEBCDIC(StringUtil.padWithChar(database,' ', 18)) ))
drda:addParameter( DRDAParameter:new( CodePoint.USRID, StringUtil.toEBCDIC(username) ) )
drda:addParameter( DRDAParameter:new( CodePoint.PASSWORD, StringUtil.toEBCDIC(password) ) )
return drda
end,
--- Builds an ACCRDB DRDA packet
--
-- @param database string containing the database name
-- @param rdbaccl string containing the RDB access manager class
-- @param prdid string containing the product id
-- @param typdefnam string containing the data type definition name
-- @param typdefovr string containing the data type definition override
-- @return drda DRDA instance
ACCRDB = function( database, rdbaccl, prdid, prddata, typdefnam, crrtkn, typdefovr )
local drda = DRDA:new( DDM:new( CodePoint.ACCRDB ) )
drda:addParameter( DRDAParameter:new( CodePoint.RDBNAM, StringUtil.toEBCDIC(StringUtil.padWithChar(database,' ', 18)) ) )
if ( rdbaccl ) then
drda:addParameter( DRDAParameter:new( CodePoint.RDBACCL, rdbaccl ) )
end
if ( prdid ) then
drda:addParameter( DRDAParameter:new( CodePoint.PRDID, StringUtil.toEBCDIC( prdid ) ) )
end
if ( prddata ) then
drda:addParameter( DRDAParameter:new( CodePoint.PRDDATA, StringUtil.toEBCDIC( prddata ) ) )
end
if( typdefnam ) then
drda:addParameter( DRDAParameter:new( CodePoint.TYPDEFNAM, StringUtil.toEBCDIC( typdefnam ) ) )
end
if( crrtkn ) then
drda:addParameter( DRDAParameter:new( CodePoint.CRRTKN, crrtkn ) )
end
if( typdefovr ) then
drda:addParameter( DRDAParameter:new( CodePoint.TYPDEFOVR, typdefovr ) )
end
return drda
end
}
-- Helper Class
Helper = {
new = function(self)
local o = {}
setmetatable(o, self)
self.__index = self
return o
end,
--- Connect to the DB2 host
--
-- @param host table
-- @param port table
-- @return Status (true or false).
-- @return Error code (if status is false).
connect = function( self, host, port )
self.comm = Comm:new( host, port )
return self.comm:connect()
end,
--- Closes an open connection.
--
-- @return Status (true or false).
-- @return Error code (if status is false).
close = function( self )
self.comm:close()
end,
--- Returns Server Information (name, platform, version)
--
-- @return table containing <code>extname</code>, <code>srvclass</code>,
-- <code>srvname</code> and <code>prodrel</code>
getServerInfo = function( self )
local mgrlvlls = bin.pack("H", "1403000724070008240f00081440000814740008")
local drda_excsat = Command.EXCSAT( "", "", "", mgrlvlls, "" )
local response, param, err
local status, packet = self.comm:exchDRDAPacket( DRDAPacket:new( { drda_excsat } ) )
if ( not(status) ) then return false, err end
local drda = packet:getDRDAByCodePoint( CodePoint.EXCSATRD )
if ( drda ) then
response = {}
param = drda:getParameter( CodePoint.EXTNAM )
if ( param ) then
response.extname = param:getDataAsASCII()
end
param = drda:getParameter( CodePoint.SRVCLSNM )
if ( param ) then
response.srvclass = param:getDataAsASCII()
end
param = drda:getParameter( CodePoint.SRVNAM )
if ( param ) then
response.srvname = param:getDataAsASCII()
end
param = drda:getParameter( CodePoint.SRVRLSLV )
if ( param ) then
response.prodrel = param:getDataAsASCII()
end
else
return false, "The response contained no EXCSATRD"
end
return true, response
end,
--- Login to DB2 database server
--
-- @param database containing the name of the database
-- @param username containing the authentication username
-- @param password containing the authentication password
-- @return Status (true or false)
-- @return err message (if status if false)
login = function( self, database, username, password )
local mgrlvlls = bin.pack("H", "1403000724070008240f00081440000814740008")
local secmec, prdid = "\00\03", "JCC03010"
local tdovr = bin.pack("H", "0006119c04b80006119d04b00006119e04b8")
local crrtkn= bin.pack("H", "d5c6f0f0f0f0f0f14bc3c6f4c4012a11168414")
local drda_excsat = Command.EXCSAT( "", "", "", mgrlvlls, "" )
local drda_accsec = Command.ACCSEC( secmec, database )
local drda_secchk = Command.SECCHK( secmec, database, username, password )
local drda_accrdb = Command.ACCRDB( database, string.char(0x24,0x07), "DNC10060", nil, "QTDSQLASC", crrtkn, tdovr)
local status, packet = self.comm:exchDRDAPacket( DRDAPacket:new( { drda_excsat, drda_accsec } ) )
if( not(status) ) then return false, packet end
if ( packet:getDRDAByCodePoint( CodePoint.RDBNFNRM ) or
packet:getDRDAByCodePoint( CodePoint.RDBAFLRM ) ) then
stdnse.print_debug("drda.Helper.login: ERROR: RDB not found")
return false, "ERROR: Database not found"
end
local drda = packet:getDRDAByCodePoint( CodePoint.ACCSECRD )
if ( not(drda) ) then
return false, "ERROR: Response did not contain any valid security mechanisms"
end
local param = drda:getParameter( CodePoint.SECMEC )
if ( not(param) ) then
stdnse.print_debug("drda.Helper.login: ERROR: Response did not contain any valid security mechanisms")
return false, "ERROR: Response did not contain any valid security mechanisms"
end
if ( select(2, bin.unpack(">S", param:getData())) ~= SecMec.USER_PASSWORD ) then
stdnse.print_debug("drda.Helper.login: ERROR: Securite Mechanism not supported")
return false, "ERROR: Security mechanism not supported"
end
status, packet = self.comm:exchDRDAPacket( DRDAPacket:new( { drda_secchk, drda_accrdb } ) )
if( not(status) ) then return false, "ERROR: Login failed" end
--
-- At this point we have a few differences in behaviour
-- * DB2 has told us earlier if the DB does not exist
-- * Apache Derby will do so here, regardless of the login was
-- successfull or not
-- * Informix will tell us that the DB does not exist IF the
-- login was successfull
--
-- Therefore the order of these checks are important!!
if ( packet:getDRDAByCodePoint( CodePoint.ACCRDBRM ) ) then
return true
-- Apache Derby responds differently with usernames containing spaces
elseif ( packet:getDRDAByCodePoint( CodePoint.RDBATHRM ) ) then
return false, "ERROR: Login failed"
-- Informix responds with a SECCHKRM DDM response
elseif ( packet:getDRDAByCodePoint( CodePoint.SECCHKRM ) ) then
drda = packet:getDRDAByCodePoint( CodePoint.SECCHKRM )
param= drda:getParameter( CodePoint.SECCHKCD )
if ( param and param:getData() == "\0" ) then
return true
end
elseif ( packet:getDRDAByCodePoint( CodePoint.RDBNFNRM ) or
packet:getDRDAByCodePoint( CodePoint.RDBAFLRM ) ) then
return false, "ERROR: Database not found"
end
return false, "ERROR: Login failed"
end,
}
-- The communication class
Comm = {
new = function(self, host, port)
local o = {
host = host,
port = port,
socket = nmap.new_socket()
}
setmetatable(o, self)
self.__index = self
return o
end,
connect = function(self)
return self.socket:connect(self.host, self.port)
end,
close = function(self)
return self.socket:close()
end,
recvDRDA = function( self )
local drda_tbl = {}
repeat
local drda = DRDA:new()
local status, err = drda:receive( self.socket )
if ( not(status) ) then
return false, err
end
table.insert(drda_tbl, drda)
until ( not(drda.DDM:isChained()) )
return true, drda_tbl
end,
--- Sends a packet to the server and receives the response
--
-- @param DRDAPacket
-- @return status true on success, false on failure
-- @return packet an instance of DRDAPacket
exchDRDAPacket = function( self, packet )
local drda, err
local status, err = self.socket:send( tostring(packet) )
if ( not(status) ) then
stdnse.print_debug("drda.Helper.login: ERROR: DB2Socket error: %s", err )
return false, ("ERROR: DB2Socket error: %s"):format( err )
end
status, drda = self:recvDRDA()
if( not(status) ) then
stdnse.print_debug("drda.Helper.login: ERROR: DB2Socket error: %s", drda )
return false, ("ERROR: DB2Socket error: %s"):format( drda )
end
return true, DRDAPacket:new( drda )
end
}
-- EBCDIC/ASCII Conversion tables
a2e_hex = "00010203372D2E2F1605250B0C0D0E0F101112133C3D322618193F271C1D1E1F"
a2e_hex = a2e_hex .. "405A7F7B5B6C507D4D5D5C4E6B604B61F0F1F2F3F4F5F6F7F8F97A5E4C7E6E6F"
a2e_hex = a2e_hex .. "7CC1C2C3C4C5C6C7C8C9D1D2D3D4D5D6D7D8D9E2E3E4E5E6E7E8E9ADE0BD5F6D"
a2e_hex = a2e_hex .. "79818283848586878889919293949596979899A2A3A4A5A6A7A8A9C04FD0A107"
a2e_hex = a2e_hex .. "202122232415061728292A2B2C090A1B30311A333435360838393A3B04143EE1"
a2e_hex = a2e_hex .. "4142434445464748495152535455565758596263646566676869707172737475"
a2e_hex = a2e_hex .. "767778808A8B8C8D8E8F909A9B9C9D9E9FA0AAABAC4AAEAFB0B1B2B3B4B5B6B7"
a2e_hex = a2e_hex .. "B8B9BABBBC6ABEBFCACBCCCDCECFDADBDCDDDEDFEAEBECEDEEEFFAFBFCFDFEFF"
e2a_hex = "000102039C09867F978D8E0B0C0D0E0F101112139D8508871819928F1C1D1E1F"
e2a_hex = e2a_hex .. "80818283840A171B88898A8B8C050607909116939495960498999A9B14159E1A"
e2a_hex = e2a_hex .. "20A0A1A2A3A4A5A6A7A8D52E3C282B7C26A9AAABACADAEAFB0B121242A293B5E"
e2a_hex = e2a_hex .. "2D2FB2B3B4B5B6B7B8B9E52C255F3E3FBABBBCBDBEBFC0C1C2603A2340273D22"
e2a_hex = e2a_hex .. "C3616263646566676869C4C5C6C7C8C9CA6A6B6C6D6E6F707172CBCCCDCECFD0"
e2a_hex = e2a_hex .. "D17E737475767778797AD2D3D45BD6D7D8D9DADBDCDDDEDFE0E1E2E3E45DE6E7"
e2a_hex = e2a_hex .. "7B414243444546474849E8E9EAEBECED7D4A4B4C4D4E4F505152EEEFF0F1F2F3"
e2a_hex = e2a_hex .. "5C9F535455565758595AF4F5F6F7F8F930313233343536373839FAFBFCFDFEFF"
-- Creates the lookup tables needed for conversion
a2e_tbl = bin.pack("H", a2e_hex)
e2a_tbl = bin.pack("H", e2a_hex)
-- Handle EBCDIC/ASCII conversion
StringUtil =
{
--- Converts an ASCII string to EBCDIC
--
-- @param ascii string containing the ASCII value
-- @return string containing the EBCDIC value
toEBCDIC = function( ascii )
local ret = ""
for i=1, #ascii do
local val = ascii.byte(ascii,i) + 1
ret = ret .. a2e_tbl:sub(val, val)
end
return ret
end,
--- Converts an EBCDIC string to ASCII
--
-- @param ebcdic string containing EBCDIC value
-- @return string containing ASCII value
toASCII = function( ebcdic )
local ret = ""
for i=1, #ebcdic do
local val = ebcdic.byte(ebcdic,i) + 1
ret = ret .. e2a_tbl:sub(val, val)
end
return ret
end,
--- Pads a string with a character
--
-- @param str string to pad
-- @param chr char to pad with
-- @param len the total length of the finnished string
-- @return str string containing the padded string
padWithChar = function( str, chr, len )
if ( len < #str ) then
return str
end
for i=1, (len - #str) do
str = str .. chr
end
return str
end,
}
return _ENV;
@KyuuKazami