Customizing John the Ripper.John the Ripper's behavior can be customized by editing itsconfiguration file. The configuration file can be named eitherjohn.conf (on Unix-like systems) or john.ini (on systems which have anotion of filename "extensions" and limit them to 3 characters).This file is searched for in private John's "home directory" and, ifnot found in the private directory and John is installed system-wide,also in John's system-wide shared data files directory.You can set global options, define wordlist and "single crack" moderules, define parameters for "incremental" modes, or even define a newexternal cracking mode.The configuration file consists of several sections. Each sectionstarts with a line containing its name, in brackets ("[...]"). Sectionsconsist either of "variable = value" assignments (each on its own line)or of some other content specific to the particular section's type(names of such sections start with "List."). Section and variable namesare not case sensitive. Comment lines start with a hash character ("#")or a semicolon (";") and are ignored. Also ignored are any empty lines.General options.Some global options can be defined in the [Options] section. Currently,you can set the following options:Wordlist = FILENAMESet this to your wordlist file name, to be used in batch mode (which isactivated when you start John with password files, but not specifying acracking mode). The default is "$JOHN/password.lst", that is, the filenamed "password.lst" in John's "home directory".Idle = Y|NIf set to "Y" (yes), John will try to use idle processor cycles only,thereby greatly reducing its impact on other system processes. Theimpact on performance of John itself is negligible except on otherwiseoverloaded systems. This setting does not affect John's startup timeand non-cracking invocations of John; it only affects the actualcracking. The default is "Y" (yes).Starting with version 1.7.7, this setting is ignored for OpenMP-enabledhash types when the actual number of threads is greater than 1.Unfortunately, it did not work right at least with GNU libgomp on Linux.Save = SECONDSThis is the time interval (in seconds) between crash recovery fileupdates. The default is 600 seconds (10 minutes).Beep = Y|NIf set to "Y" (yes), John will beep when a password is found. OnUnix-like systems, it does this by sending the bell character (ASCIIcode 7) to the "standard error" file descriptor (which is normallydirected to the terminal). The default is "N" (no).Defining wordlist and "single crack" modes rules.The word mangling rules for wordlist and "single crack" modes aredefined in separate sections, [List.Rules:Wordlist] and[List.Rules:Single], respectively. John the Ripper uses an extension ofCrack's syntax for the rules. John supports all of the commands ofCrack 5.0a plus a few more and, most importantly, it adds apreprocessor, which can generate multiple rules from a single sourceline.When defining rules, simply place one rule (which may includepreprocessor commands) per line. See RULES for information on the rulessyntax and on the preprocessor."Incremental" mode parameters.To define the incremental mode parameters you need to create a sectioncalled [Incremental:MODE], where MODE is any name that you assign to themode. There are some pre-defined incremental modes in the defaultconfiguration file supplied with John, you can use them as templates.The following parameters are supported:File = FILENAMESet this to your charset file name. See EXAMPLES for an example on howto generate a custom charset file. There's no default.MinLen = LENGTHMinimum password length (the number of characters) to try. The defaultis 0.MaxLen = LENGTHMaximum password length to try. The default is 8 (or CHARSET_LENGTH asdefined in src/params.h at compile time).CharCount = COUNTThis allows you to limit the number of different characters (or rather,character indices) used. The effect is that John would favor simplelonger candidate passwords over more complicated shorter ones, and wouldnever attempt rare characters and character combinations, not even forreally short passwords. Most of the time, this is undesired. Anotheruse for this option is to make John print a warning if the charset onlydefines less than CharCount characters; this is how the pre-defined"incremental" modes use it. The default is to use as many differentcharacters as are defined.Extra = CHARACTERSThis can be used to make John try some extra characters that don'tappear in the charset file. Just list all those characters here andthey will be added, but considered the least probable.Defining an external mode.See EXTERNAL.$Owl: Owl/packages/john/john/doc/CONFIG,v 1.5 2011/02/27 07:16:16 solar Exp $