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Diffstat (limited to 'nselib/drda.lua')
| -rw-r--r-- | nselib/drda.lua | 775 |
1 files changed, 775 insertions, 0 deletions
diff --git a/nselib/drda.lua b/nselib/drda.lua new file mode 100644 index 0000000..9ef74a0 --- /dev/null +++ b/nselib/drda.lua @@ -0,0 +1,775 @@ +--- +-- 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 https://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 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.debug1("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.debug1("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.debug1("drda.DRDA.toString: DDM cannot be nil") + return nil + end + + local data = { + string.pack(">I2BBI2I2I2", 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+1] = tostring(v) + end + return table.concat(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.debug1("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 ) + return string.pack(">I2I2", self.Length, self.CodePoint) .. (self.Data or "") + 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 + self.Length, self.CodePoint, pos = string.unpack( ">I2I2", data, pos ) + + if ( self.Length > 0 ) then + self.Data, pos = string.unpack("c" .. 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 string.pack(">I2BBI2I2I2", 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 + + self.Length, self.Magic, self.Format, self.CorelId, self.Length2, self.CodePoint, pos = string.unpack( ">I2BBI2I2I2", 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 ( (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 = ( self.Format ~ self.Formats.CHAINED ) + else + self.Format = ( 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 = stdnse.fromhex("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 = stdnse.fromhex("1403000724070008240f00081440000814740008") + local secmec, prdid = "\00\03", "JCC03010" + local tdovr = stdnse.fromhex("0006119c04b80006119d04b00006119e04b8") + local crrtkn= stdnse.fromhex("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, "\x24\x07", "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.debug1("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.debug1("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 ( string.unpack(">I2", param:getData()) ~= SecMec.USER_PASSWORD ) then + stdnse.debug1("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 + -- successful or not + -- * Informix will tell us that the DB does not exist IF the + -- login was successful + -- + -- 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.debug1("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.debug1("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\z +405A7F7B5B6C507D4D5D5C4E6B604B61F0F1F2F3F4F5F6F7F8F97A5E4C7E6E6F\z +7CC1C2C3C4C5C6C7C8C9D1D2D3D4D5D6D7D8D9E2E3E4E5E6E7E8E9ADE0BD5F6D\z +79818283848586878889919293949596979899A2A3A4A5A6A7A8A9C04FD0A107\z +202122232415061728292A2B2C090A1B30311A333435360838393A3B04143EE1\z +4142434445464748495152535455565758596263646566676869707172737475\z +767778808A8B8C8D8E8F909A9B9C9D9E9FA0AAABAC4AAEAFB0B1B2B3B4B5B6B7\z +B8B9BABBBC6ABEBFCACBCCCDCECFDADBDCDDDEDFEAEBECEDEEEFFAFBFCFDFEFF" + +e2a_hex = "000102039C09867F978D8E0B0C0D0E0F101112139D8508871819928F1C1D1E1F\z +80818283840A171B88898A8B8C050607909116939495960498999A9B14159E1A\z +20A0A1A2A3A4A5A6A7A8D52E3C282B7C26A9AAABACADAEAFB0B121242A293B5E\z +2D2FB2B3B4B5B6B7B8B9E52C255F3E3FBABBBCBDBEBFC0C1C2603A2340273D22\z +C3616263646566676869C4C5C6C7C8C9CA6A6B6C6D6E6F707172CBCCCDCECFD0\z +D17E737475767778797AD2D3D45BD6D7D8D9DADBDCDDDEDFE0E1E2E3E45DE6E7\z +7B414243444546474849E8E9EAEBECED7D4A4B4C4D4E4F505152EEEFF0F1F2F3\z +5C9F535455565758595AF4F5F6F7F8F930313233343536373839FAFBFCFDFEFF" + +-- Creates the lookup tables needed for conversion +a2e_tbl = stdnse.fromhex(a2e_hex) +e2a_tbl = stdnse.fromhex(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 ) + return string.gsub(ascii, ".", function(a) + local val = a:byte() + 1 + return a2e_tbl:sub(val, val) + end) + end, + + --- Converts an EBCDIC string to ASCII + -- + -- @param ebcdic string containing EBCDIC value + -- @return string containing ASCII value + toASCII = function( ebcdic ) + return string.gsub(ebcdic, ".", function(e) + local val = e:byte() + 1 + return e2a_tbl:sub(val, val) + end) + 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 finished string + -- @return str string containing the padded string + padWithChar = function( str, chr, len ) + return str .. string.rep(chr, len - #str) + end, +} + +return _ENV; |