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js-obfus - obfuscate (make more difficult to understand) JavaScript source code

NAME
SYNOPSIS
DESCRIPTION
Advanced support for protecting dynamic JavaScript
Advanced support for protecting fragments of dynamic clientside JavaScript in the statements of server-side language
Support for ensuring licensing conditions
OPTIONS
RETURN VALUE
DIAGNOSTICS
EXAMPLES
FILES
NOTES

NAME

js-obfus - obfuscate (make more difficult to understand) JavaScript source code programs

SYNOPSIS

js-obfus [ -v|--version ] [ --noparsing ] [ --output-line-len N ] [ --jam 0|1 ] [ --keep-spaces ] [ --keep-newlines ] [ --keep-comments ] [ --transform-comments] truncate|chars2x|nonwhites2x |keep-original|replace-with-newlines] [ --bannerhead filename] [--bannertail filename ] [ --skip-external-parser ] [ --skip-all-newlines ] [ --inline-regexps disable|warn|enable ] [ --input-encoding name-of-file-character-encoding ] [ --locals-handling as-others|minify-only|minify-then-mangle ] [ --SN name_of_SN_sub] [ -o destination-filename ] [ --excludeidentsfile|-x filename ].. [ --excludeidentsfile-anycase filename ].. [ -X filename ].. [ --suffixes-asis-list filename ].. [ -F user-defined-mapping-filename ].. [ -d map-filename ] [--embed-map] [ -e encode-count ] [ -D list-of-symbols-filename ] [ -i idents-mangling-params ] [ -n number-mangling-params ] [ -s string-mangling-params ] [ -c charcode-mangling-params ] [ -S server-mode-params ] [ -T time-asserter-params ] [ -H hostname-asserter-params ] [ -G generic-asserter-params ] [ -E extractor-params ] [ -O profile-name ] file-to-obfuscate

DESCRIPTION

This program turns JavaScript source code files into functionally equivalent JavaScript source code that is much more difficult to study, analyze and modify - thus providing you control over intellectual property theft. It works perfectly with multi-module programs and for programs that depend on a lot of third-party modules that are not subject to obfuscation. By default it also encodes the obfuscated version of the file and makes it self-decoding at runtime thus not requiring any standalone decoder, and making the file completely non-understandable by anybody.

JavaScript Obfuscator also allows to ensure licensing conditions of the code at runtime by providing any combination of lifetime period expiration control, advanced hostname checking and generic user-defined checks; in case licensing conditions are not met, there is an option to delete obfuscated file automatically, print user-defined message and terminate the execution or ability to execute user-implemented code. All checking of licensing conditions are additionally encoded to make them very difficult to analyze. The block of code that checks for licensing conditions can't be removed from the obfuscated program since it's made dependant on the initialization functionality performed by that block.

JavaScript Obfuscator also has auxilary no-parsing mode in which it doesn't try to obfuscate the code at all, code is only encoded in this mode. This mode is useful for quick and unperfect source code hiding only. This mode is not default one, it can be activated by passing --noparsing commandline switch.

This program typically obfuscates only one JavaScript source file at a time, reading source code file from stdin and writing output to stdout. It's possble to request it to save the output directly to a file using -o switch. There are special aids to protect several files at once, this is done using multifile ``mode'' - see description of it in the documentation of the -S option below.

All comments are stripped away by default, but this can be switched off by passing the --keep-comments switch. It's possible to add comments with author and copyright information to the top and to the end of the obfuscated version of the file using options --bannerhead and --bannertail respectively. Of course these comments will appear in clear text form in the obfuscated file, independant of whether encoding was applied to it.

There a special server mode of operation too - in which JavaScript Obfuscator parses its commandline, initializes internal state and starts accepting requests in some way from clients; when a client passes it input to process, it obfuscates and encodes given input according to the commandline options JavaScript Obfuscator was started with, and returns processed input to the client, waiting for a next client's request. See more information on this in the documentation for the -S commandline option.

The obfuscation typically means

replacing all symbol names it's possible to with the non-meaningfull ones, e.g. replacing variable files with zcadaa4fc81, while preserving synaxical and semantical correctness of the source code. Of course predefined symbols like document and symbols from the third-party or standard libraries the source code uses will be left the same so the obfuscated code will still work without requiring to obfuscate those third-party and standard libraries.
substitution of numeric values with the arithmetic expressions using (random or constant for the same numeric value as requested by the options) decimial and hexadecimial numeric values that evaluate to the same value
using hexadecimial character codes for all characters in strings
removing extra white space
jamming as much code on each line (of length not more than specified using --output-line-len option) as possible if --jam=0 is not specified

Add to that the fact that the obfuscated code will also be encoded thus making the source code completely unreadable.

The non-encoded obfuscated code is extremely difficult to understand for a human since the name of variables and subroutines and other symbols are totally meaningless and hard to remember (e.g. files becomes zcadaa4fc81). It's possible to control most aspects of obfuscation using the commandline switches of the JavaScript Obfuscator.

If the source file uses eval for strings that include variable and function names, then you have to make minor modifications to the file (otherwise, for obvious reasons, after obfuscation the string to be evaled will refer to undeclared variables and functions). To overcome this, the JavaScript Obfuscator supports a special function named OBJNAME (it can be changed by the use of --SN switch). The special meaning of this function is turned on if its argument is a string constant in single quotes. The special support is treating its argument as symbol name, and mangling the symbol name as all symbols are mangled. I.e. OBJNAME('myvar') becomes OBJNAME('MANGLED_myvar') (the name of functions treated as OBJNAME will never become obfuscated - so you don't need to include them in exceptions list). Using other way of passing arguments to it won't enable the special treating so you should use only the supported ways only. So it should be used if your code generates strings that are then eval'ed - e.g. instead of eval('abc = ' + value + ";") you should write eval(OBJNAME('abc') + " = " + value + ";"). If you also need to run your code non-obfuscated too, you should cut and paste definition of the OBJNAME subroutine like this:

     function OBJNAME(n) { '';return n; }

In order names of symbols from external libraries not to be mangled, you have to specify names of files with exceptions using --excludeidentsfile or --excludeidentsfile-anycase options. For convenience, there is a -X switch that can be passed multiplie times to specifies the names of files in which list of exceptions to ignore are stored (useful if e.g. default set of exceptions JavaScript Obfuscator uses is too broad for your project).

It's possible to request JavaScript Obfuscator to save list of symbols it encountered in the file by passing its name using -D switch. This may be useful for generating list of exceptions from some library file.

It's possible to request JavaScript Obfuscator to save the mapping between obfuscated symbol names and original symbol names in the external file by passing the filename after -d switch.

Encoding can be controlled with the -e switch, to completely turn it off add -e 0 to the js-obfus command line. It's possible to request to encode part of the input files, leaving some fragments just obfuscated. See more information in the documentation about the -E option, in the description of the so-called extractor with name code.

By default JavaScript Obfuscator perfectly supports JavaScript files in which statements may be terminated with newline, though it's a bad programming style; this support for badly-styled sources means that JavaScript Obfuscator may preserve unneeded newlines in obfuscated code. If you are sure the file being obfuscated doesn't have such newlines, you can get rid of these possible unneeded newlines in the obfuscated code by passing --skip-all-newlines switch.

Advanced support for protecting dynamic JavaScript

If the program generates or creates dynamic JavaScript using ``print''-like functions (or method of some object), then it's also possible to protect it. In order to achieve this, one has to identify which functions or methods accept the single string argument that is a text of dynamic JavaScript code, specify the names of such objects and their methods separated with plus sign immediately after the following commandline parameter:

  -O .,handle-dynamic-scripts=1,dynamic-scripts-by=

E.g. if all dynamic JavaScript code is output using methods ``write'' and ``writeln'' of object ``codeout'', then one has to add the following to the commandline:

  -O .,handle-dynamic-scripts=1,dynamic-scripts-by=codeout.write+codeout.writeln

Then the dynamic JavaScript code in the following 2-line file named foo.js:

    codeout.write("foo1 = '" + some_arr[3] + "';some_function(foo1);");
    codeout.writeln("foo1 = '" + (othervar? 12 : 15) + "';other_function(foo1);");

protected using the following commandline:

 js-obfus -e 0 -s none foo.js -O .,handle-dynamic-scripts=1,dynamic-scripts-by=codeout.write+codeout.writeln

will produce the following result:

 z621f0012f2.write("zfc1f0bbd67 = '"+z9231d6e25d[(0x58c+1878-0xcdf)]+
 "';z0554eb4945(zfc1f0bbd67);");z621f0012f2.writeln("zfc1f0bbd67 = '"+(
 z687818d33b?(0xe31+2396-0x1781):(0xfc6+4826-0x2291))+
 "';z00425f1261(zfc1f0bbd67);");

As you can see, the argument of the method can even be calculated using other variables - JavaScript Obfuscator correctly detects what is piece of dynamic JavaScript and what is not. You only have to make sure that nothing except dynamic JavaScript code is passed as an argument to those functions (i.e. it can't be html code); if it's not the case, you will have to alter your source code and introduce ``aliases'' - objects that will be used only for processing of dynamic JavaScript code.

If dynamic JavaScript is passed as an argument of the function (i.e. not a method of some object) - just specify function name.

If dynamic JavaScript is passed as an argument of the method that is invoked for a lot of different objects (but for all objects the argument of this method is dynamic JavaScript code) - just specify the name of the method.

Advanced support for protecting fragments of dynamic clientside JavaScript in the statements of server-side language

JavaScript Obfuscator also has unique ability to protect dynamic clientside JavaScript code in the statements of almost any server-side language (e.g. PHP, JSP, C/C++, ASP or ASP.NET and sometimes Perl). The only requirements for supported server-side language is using parenthesis for surrounding function and method arguments and using single or double quotes for delimiting string constants - most of the server-side languages meet these requirement.

In order dynamic JavaScript code to be obfuscated, one has to tell JavaScript Obfuscator which objects and their methods are used for processing dynamic JavaScript code by specifying the names of such objects and their methods separated with plus sign immediately after the following commandline parameter:

  -E .,handle-dynamic-scripts=1,dynamic-scripts-by=

The limitation is that you will have to add this part of commandline after all other commandline arguments.

So if we have the following in the file 1.asp:

 <script language=javascript><!--
 var foo1;
 function some_function(x) {};
 function other_function(x) {};
 <%
    codeout.write("foo1 = '" + some_arr[3] + "';some_function(foo1);");
    codeout.writeln("foo1 = '" + (othervar? 12 : 15) + "';other_function(foo1);");
  %>
  --></script>

protected using the following commandline:

 js-obfus -e 0 -s none foo.asp -E html -E .,handle-dynamic-scripts=1,dynamic-scripts-by=codeout.write+codeout.writeln

will produce the following result:

 <script language=javascript><!--
 var zfc1f0bbd67;function z0554eb4945(x){};
 function z00425f1261(x){};<%
    codeout.write("zfc1f0bbd67 = '" + some_arr[3] + "';z0554eb4945(zfc1f0bbd67);");
    codeout.writeln("zfc1f0bbd67 = '" + (othervar? 12 : 15) + "';z00425f1261(zfc1f0bbd67);");
   %>
 --></script>

If dynamic JavaScript is passed as an argument of the function (i.e. not a method of some object) - just specify function name.

Support for ensuring licensing conditions

JavaScript Obfuscator has advanced support for ensuring licensing conditions (not available in Trial editions). It's possible to ensure licensing conditions by any combination of the following criterias:

lifetime expiration
hostname matching
arbitrary check implemented by user

Each type of checking criterias is implemented by subengines called asserters from here - the specific asserters are called time asserters, hostname asserters and generic asserters correpondingly from now. There are several subtypes of asserters of each type, each with different behaviour; it's possible to enable only one subtype of asserters of a given type (i.e. no more than one time asserter, no more than one hostname asserter, etc).

By default no asserters of any type are enabled.

If any asserter is enabled, the special block of code is prepended to the obfuscated version of original code; if it was requested to additionally encode the obfuscated code then the resultant code (special block and obfuscated version of original code) will be encoded as a whole.

In any case that special block of code will actualy be an encoded version of the code that will include implementation of all checks and actions to be performed in case licensing conditions are not met AND special initialization code without which the obfuscated version of original code will not work correctly (the special initialization code is in fact an initialization of variables used in some part of expressions inside the obfuscated version of original code). This means that it's impossible to remove the special block that includes checks for ensuring licensing conditions without making the rest of the code malfunctioning, even if user selected to just obfuscate (without applying encoding) the original source.

Asserters are configured from a command line in a similar way to token mangling parameters. Use -T option to configure time asserters, -H to configure hostname asserters, -G to configure generic asserters. See description of the individual asserters of each type for more information about their options.

OPTIONS

Note that there is interacive web-based commandline builder for JavaScript Obfuscator available at http://www.stunnix.com/support/interactive/cmd-builder/.

-v|--version

Output version information and exit.

--output-line-len N

Set the maximum line length for the obfuscated file. However, if some string constant will be longer than this limit, it won't be split or otherwise wrapped, resulting in a line longer than an amount specified. The default value for parameter N is 80.

--jam 0|1

Control whether to omit extra white spaces. When argument is 1, all extra white spaces (including carridge returns) are omitted, that makes the obfuscated file looking even less readable. When argument is 0, the obfuscated (but not encoded) file will look like original file with respect to spaces and newlines - in particular it will have the same identation. By default jamming is enabled (value is 1).

--keep-spaces

Request not to skip extra spaces in the lines (whitespaces and tabs) if jamming is enabled (which is the default). By default extra spaces in the line are ignored if jamming is enabled.

--keep-newlines

Request not to skip newlines if jamming is enabled (which is the default). By default newlines are ignored if jamming is enabled.

--skip-all-newlines

--keep-comments

Requests to keep all comments. By default all comments are stripped away.

--transform-comments replace-with-newlines|truncate|chars2x|nonwhites2x|keep-original

If --keep-comments is specified on the commandline, this option specifies what to do with comments. By default comments are not modified (this corresponds to value keep-original of this option). The possible values for this option are:

replace-with-newlines: If specified, comment delimiters and their bodies are removed, and are replaced with newlines contained in the comment bodies (thus keeping line numbers in sync with original code, but not revealing locations where comments were located).
truncate: If specified, only newlines are kept in bodies of comments.
chars2x: If specified, newlines are kept in bodies of comments, and all other characters including spaces are replaced with character 'x'. This is useful to show that original code contained some comments, and give an impression on what length of them was.
nonwhites2x: If specified, newlines are kept in bodies of comments, and all other characters except whitespaces are replaced with character 'x', whitespaces are left as is. This is useful to show that original code contained some comments, and give an impression on what length of them was, and what content they had approximately (since a lot of comments in the code happen to be various separators formed by repeating some character like dash for entire length of the line).
keep-original: If specified, comments are kept as they were in original code. This is a default value for this option.

--bannerhead filename

--bannertail filename

Specify the file whoose content will be prepended or appended to the obfuscated file. This is most useful for adding comments with copyright and license information. Such comments will be visible as clear text in any file that was obfuscated and/or encoded.

--skip-external-parser

Passing this option disables use of external JavaScript parser. In general, using this option is not recommended - it makes sense to use it only if told by support team.

--inline-regexps disable|warn|enable

Specify the handling of literal text format of RegExp object's constructors. If some file contains expressions that can erroneously be parsed as literal text format of RegExp object's constructors, pass disable this switch to completely disable recognition of regular expressions. If value passed is enable or warn, support for recognition will be enabled. If value passed is warn, JavaScript Obfuscator will print the string it treated as regular expression to standard error output. The default value for the switch is enable.

--input-encoding name-of-file-character-encoding

Specify the name of character encoding that script texts are in. Specify character encoding here if you encode your scripts and strings in your scripts are not in iso8859-1 encoding. The name of encoding should be known to Perl's module Encode.pm (e.g. iso8859-3, or koi8-r). The default value for the switch is none, which is OK for most of users.

--locals-handling as-others|minify-only|minify-then-mangle

Specify handling of local variables (and function arguments). By default, they are handled like all other symbols. In case the value of this switch is not as-others, implementation of JavaScript parser from Mozilla project (implemented in Java) is started to analyze javascript code and assign shortest possible names to local variables (identically to the way YUICompressor does it) with respect to the scope of local variables. This means in output name A will be assigned to different local variables in different functions.

In case the code contains syntax errors, fallback behaviour will be used (as if value of this option was as-others), so it still allows you to protect code that looks invalid (e.g. due to presence of server-side markup inside javascript code). This means that if you specify anything but as-others to this switch, Java runtime will be very desired, but its absence will not cause a failure.

If the value of the switch is minify-only, the shortest names assigned by Java backend will be used in the output, independent from the symbol mangler used for non-local variables (e.g. non-local symbols can be md5-mangled, resulting in compact and cryptic output).

If the value of the switch is minify-then-mangle, the shortest names assigned by Java to local vars are mangled using the same mangler as non-local vars. This lets protected output to look more cryptic than when value as-others is used, since e.g. local variable ``blah'' will get different names in different functions (if the value of the option is as-others, the local variable ``blah'' will get the same name in each function it's declared and/or used).

Using Java backend makes protecting slower, so beware.

The default value for this switch is as-others.

--SN name_of_SN_sub

Specify the name of the sub that will be treated as OBJNAME. See above for the description on what this sub is for. Default value is of course OBJNAME.

-o destination-filename

Output the obfuscated version to the named file. There is no default value for this option - i.e. the obfuscated file is written to stdout by default.

--excludeidentsfile filename

-x filename

This option can be specified more than once. It allows to specify the names of files that contain a list of symbol names that won't be mangled, one symbol per line. Such symbols are called exceptions from this point. Comments are allowed in such files by placing a hash sign (#) as the first character of the line. The file name specified is first searched in the current directory (if it's not absolute path), and then in the subdirectory lib/js-obfus/exceptions/ of the directory where JavaScript Obfuscator was installed to. There is no need to add names of JavaScript pre-defined variables and functions - they are already hardcoded into JavaScript Obfuscator. The default set of exceptions JavaScript Obfuscator uses can be controlled in the file that stores ``persistent settings'' for it - located in the lib/js-obfus/js-obfus-settings.pl in the directory where JavaScript Obfuscator was installed.

It's possible to remove symbols from lists of exceptions by passing names of files with these symbol names using -X switch.

The filename can be name of directory, in this case all files located in this directory and any of its subdirectories (at any depth) are loaded as if the names of these files were specified individually one-by-one.

--excludeidentsfile-anycase filename

This option is very similar to --excludeidentsfile, except that symbols read from the specified file are treated as case-insensitive exceptions. This functionality is useful for listing methods and properties of ActiveX objects, that are case-insensitive.

-X filename

This option can be specified more than once. It allows to specify the names of files that contain a list of symbol names that should be mangled, even if those symbol names were in the files with names passed with -x switch (i.e. for disabling some exceptions). At first files specified with -x switch are processed, and then files specified with -X switch are processed.

Comments are allowed in such files by placing a hash sign (#) as the first character of the line. The file name specified is first searched in the current directory (if it's not absolute path), and then in the subdirectory lib/js-obfus/exceptions/ of the directory where JavaScript Obfuscator was installed to.

This option is mostly useful in case the set of exceptions created from builtin list and content of files passed with -x switch is too broad.

--suffixes-asis-list filename

This option can be specified more than once. It allows to specify the names of files that contain a list of suffixes that should be preserved in symbols being mangled. E.g. if suffix onclick is listed in some file mentioned by this option, then symbol myButton_onclick will be mangled to something like z2b9a0ec6d_onclick, rather than to something like za40f93e635d.

This option is mostly useful for protecting code for environments, that scan name of symbol for some suffix in order to treat the symbol specially.

-F user-defined-mapping-filename

This option can be specified more than once. It allows to specify the names of files that contain user-specified mapping of symbols.

Comments are allowed in such files by placing a hash sign (#) as the first character of the line. Each line in such file contains two symbols: name of original symbol, one or more space characters, and required resultant symbol.

In case some mangling engine decides to assign a symbol that is listed as resultant symbol, special attempts will be made to guarantee that the symbol chosen by obfuscation engine won't conflict with it (by adding prefixes until unqueness is reached).

-d map-filename

This option specifies the name of file to write the mapping between obfuscated symbol names and non-obfuscated symbol names to. Such mapping may be useful for analyzing JavaScript error messages that contain obfuscated symbol names - just find the line with the symbol JavaScript interpreter complained about, and the second word on that line will be the original symbol name. Please keep in mind that it will be much easier for a person having access to such mapfile to study the code, so it's highly suggested to keep such map file in secure place and not to distribute it to the customers.

If the file specified with this option exists, the accumulated mapping information will be merged with mapping information previously stored in the file - this allows one to have map file for entire project.

By default no filename is specified, and thus mapping information is not saved anywhere.

--embed-map

This option instructs the mapping between obfuscated symbol names and original symbol names to be appended inside a comment to the result of processing, in form of couple of strings per line - obfuscated symbol name and original symbol name. For symbols that are exceptions (i.e. for ones obfuscated symbol name is the same as original) such lines are not emitted at all. Lines are emitted only for symbols found in subject file.

By default this mapping information is not embedded at all.

-e encode-count

This option controls the number of encoding iterations to be applied to obfuscated file. To disable encoding completely one should specify 0 as number of encoding iterations. It's not recommended to apply more than 30 encoding iterations. Each encoding iteration increases output file size. The relation between non-encoded obfuscated file size and encoded obfuscated file size is approximately the following: E=I*2+N*450 where E is encoded size, I is non-encoded obfuscated size, and N is the number of iterations applied. The default value for this option is 10.

-D list-of-symbols-filename

Instructs JavaScript Obfuscator to save a list of symbols encountered during processing to the list-of-symbols-filename. The file will be overwritten. This is useful e.g. when generating a list of exceptions from some library, since the resultant file can be used for passing to -x or -X switches while processing files that use that library.

--noparsing

This is additional mode of operation in which JavaScript Obfuscator only encodes the file. In this mode no parsing of code is performed, no obfuscation of any type applied (e.g variables are not renamed, numbers are not turned to expressions, and so on) and comments are not removed, but the original code becomes unreadable. Code encoded in this mode is guaranteed to work the same way it was working before encoding, without a need of any modifications to it.

If this mode is activated, only the following options are in effect: all related to encoding - i.e. -e, and --bannerhead, --bannertail .

-i idents-mangling-params

-n number-mangling-params

-s string-mangling-params

-c charcode-mangling-params

Specify options for mangling of tokens of each type. The argument is mangling-specification, that has the following syntax:

obfuscator-title[,option=value]..

Tokens of each type can be mangled using different approaches, each approach corresponds to obfuscator, identified by obfuscator-title. Each obfuscator can have options that alter its behaviour, in order to specify them the comma separated option=value pairs may follow obfuscator-title after a comma.

The mangling-specification specifies all details on how to mangle tokens of each type, so if multiplie occurences of the option are specified, the last one is taken into the effect.

For each type of token a special obfuscator with title none is available - it doesn't alter the tokens in any way.

Here is a list of obfuscators for each type of the token, with the options they support.

-i = obfuscators for symbol names

It's obvious that symbols with the same name should be obfuscated to the same name, independant of location in the program these symbol names are locatged. It also should be obvious that entire set of modules and scripts that uses them should be obfuscated using the same value of mangling-specification - otherwise there will appear undeclared symbols.

obfuscator none

Selecting this obfuscator will keep symbol names unchanged.

obfuscator combs

This obfuscator replaces names of symbols with names consisting of all possible combinations of characters, specified via option spec, of the length specified via option minlen. E.g. it can replace formname with IlI and mystr with llI (which both look very similar to the human eye) if user specified the value of spec option as Il.

The replacement symbol depends solely on the index of symbol being seen for the first time in the project, and on the value of seed argument.

The detection of collisions for symbols in the current file is done automatically. It's possible to activate detection of collisions for symbols in entire project by the use of adhere-mapfile option of this symbol obfuscator.

If option adhere-mapping is specified for this obfuscator and has non-zero value and if mapfile name is specified via global option -d, then JavaScript Obfuscator will read specified mapfile at startup, and will try to lookup the original symbol names in it and use a replacement from that file if found; it will also ensure that protected symbols that were produced during that invokation of JavaScript Obfuscator are not assigned to any symbol listed in mapfile (and if it encounters some obfuscated symbol it was going to use as a replacement as being used as a replacement for another symbol (i.e. so-called ``hash-collision'' occurs) then execution of JavaScript Obfuscator is aborted with error message - in which case it's necessary to clear mapfile, change the seed and/or increase value of len option and protect entire application again); after processing completes, mapfile will be updated as usual.

Note, that shortest symbol obfuscator also can generate protected symbols using all possible combinations of characters, but it allows to generate shortest names possible at the same time (by requiring 2 passes on each source file).

Options:

adhere-mapfile: See description of combs obfuscator for more information on this option. The default value is 0.
seed: The value of this option affects the order in which all possible combinations of characters used for symbol name are chosen. The value can be arbitrary string.
minlen
len: Minimal length of generated symbol. Once all combinations of characters of a given length were used for generating symbol names, the length of resultant symbol name is automatically increased. This means it's not necessary to make the value of this option very long - set it to big enough value that makes your code acceptably unreadable and acceptably big. It's impossible to assign value lower than 4 to this option. The default value is for this option is 10.
spec: The value of this option instructs which characters can be used for generating names of symbols, the value should either be string that is a concatenation of all characters possible in the resultant symbol name, e.g. Il or OQ, or a couple of such strings separated by colon, in which case a string before the colon specifies characters that can be used for leading symbol's character, and string after the colon specifies characters that can be used for all characters of the symbol except the first (the leading) - e.g. lI:lI1 or O:O0. The recommended values are lI, O:O0 and lI:lI1. If this option is not specified, it's assumed that all characters allowed for JavaScript language to be used for symbols can form a resultant symbol name.

obfuscator mixcase

This obfuscator replaces all symbols with one of names you specify, but randomly altering case of letters in the names. E.g. if you specify spec option as strictly_confidential it will replace names of symbols with sTrictly_CONfidENTiAl, StRiCtly_cOnFiDeNTiaL, stRIctLY_coNFiDeNTiaL and other possible variantions. You can specify several replacement names via spec option, separating them with : (colon). The replacement symbol depends solely on the index of symbol being seen for the first time in the project, and on the value of seed argument.

If option adhere-mapping is specified for this obfuscator and has non-zero value and if mapfile name is specified via global option -d, then JavaScript Obfuscator will read specified mapfile at startup, and will try to lookup the original symbol names in it and use a replacement from that file if found; it will also ensure that protected symbols that were produced during that invokation of JavaScript Obfuscator are not assigned to any symbol listed in mapfile (and if it encounters some obfuscated symbol it was going to use as a replacement as being used as a replacement for another symbol (i.e. so-called ``hash-collision'' occurs) then execution of JavaScript Obfuscator is aborted with error message - in which case it's necessary to clear mapfile, and change the seed and/or use longer names in spec argument, and then clean and rebuild entire project again.

After processing completes, mapfile will be updated as usual.

Options:

adhere-mapfile

See description of combs obfuscator for more information on this option. The default value is 0.

seed

The value of this option affects the order in which all possible combinations of characters used for symbol name are chosen. The value can be arbitrary string.

spec

The value of this option specifies replacement names, separated with a colon (:). If number of all possible variants all specified names allow to produce is lower than certain amount (512), hardcoded fallback value strictly_confidential is used.

If number of symbols that need to be replaced in the project is less than number of all possible variants all specified names allow to generate, then obfuscation is aborted with error message.

It's allowed to use non-letters in the value of this option (e.g. digits and underscore).

obfuscator md5

This obfuscator calculates md5 sum of the string produced by concatentation of a constant prefix (that can be passed via seed option) and the symbol name to be obfuscated. After that from the hexadecimial representation of the md5sum several (exact length is specified using len option) leading characters are appended to another prefix (that can be set via prefix option) to form obfuscated symbol name.

It's obvious that in theory it's possible to get md5sum collision - the critical situation when two different symbols will be obfuscated to the same symbol name. When such situation is detected, the obfuscation is aborted. The detection of collisions for symbols in the current file is done automatically. If detection of collisions for symbols in entire project is required, one can use adhere-mapfile option for enforcing uniqueness of protected symbols across all files - please read the description of symbol name obfuscator combs. The only solution in case md5sum collision is detected is to change the value of the seed option or to increase the value of the len option. However, such situations are very rare.

This is the default obfuscator for symbol names.

Options:

adhere-mapfile: See description of combs obfuscator for more information on this option. The default value is 0.
seed: See above for a description of this option. The value can be arbitrary string. The default value is generated as random string at the JavaScript Obfuscator suite installation time, so it will be unique for each user of JavaScript Obfuscator.
len: Specifies how many characters of the hexadecimial representation of the md5 sum to use for obfuscated name of the symbol. The less the value, the shorter all identifiers will be, the smaller obfuscated code will become, and the easier it will be for human to study the code. Also increasing the value lowers the probability of md5sum collision. The default value is 10.
prefix: Specifies the prefix of all mangled symbol names. It should non-empty string (one character is enough) just because hex representation of md5sum can begin with a digit. There is no point in changing the prefix. The default value is z.

obfuscator prefix

This obfuscator just prepends the same string (specified via str option) to all symbol names to get the obfuscated symbol name. This obfuscator is designed to be used for initial testing of obfuscated code for locations of use of undeclared symbols in obfuscated code. It's obvious that while testing obfuscated code it's much more easier to find out what symbol is undeclared if it's trivial to correlate that symbol of the obfuscated program with the symbol of the non-obfuscated program.

Options:

str: The string to prepend to all symbol names. Default value is Z439Z_.

obfuscator shortest

This obfuscator replaces each symbol name with the shortest identifier possible, using the shorter identifiers for symbols that are used more frequently. Using this obfuscator and none obfuscators for strings and numbers will produce the most compact version of the code possible. The presence of this obfuscator turns JavaScript Obfuscator into so-called source code ``compressor''.

It's perfectly suitable for multimodule projects too. There are two modes of operation this obfuscator works in (controlled by its parameter countupdate) - scanning through the project files for computing the use counts for all symbols (used if parameter countupdate is passed value 1) and saving the counts to a special file hereafter called countsfile (whose name is specified as value of parameter countsfile) or performing the obfuscation itself using the symbol use counts from countsfile gathered during first mode of operation (used if parameter countupdate is passed value 0, or if this parameter is not specified at all). In the obfuscation mode obfuscator maintains its state (a mapping between original symbols and obfuscated ones) in the file whose name specified as a value of parameter statefile (hereafter such file will be called statefile).

Note that file with symbol counts should be up to date - at least it should mention all symbols that are subject to obfuscation - so if you added some code and introduced some new symbols, you'll have to regenerate countsfile. JavaScript Obfuscator aborts execution if it encounters that some symbol was not counted at all, with diagnostics indicating that countsfile needs to be rebuilt. Rebuilding countsfile means deleting (or truncating) the countsfile and statefile and running JavaScript Obfuscator in symbol count gathering mode on all files of the project. If your change to the code didn't introduce new symbols but just increased or decreased the use of already existing ones, it won't abort the execution but there will be a chance that size of resultant obfuscated file won't be the smallest possible.

So the common approach to using this obfuscator for symbol names is: develop and debug the code, delete files a-file-with-counts and a-file-with-state, then run the JavaScript Obfuscator with options like this -i shortest,countupdate=1,countsfile=a-file-with-counts for all source files in the project to gather symbol counts to the file a-file-with-counts, and then run JavaScript Obfuscator with options like this -i shortest,countupdate=0,countsfile=a-file-with-counts,statefile=a-file-with-state for all source files in the project.

Another option is to process all files in your project in one invokation of JavaScript Obfuscator, and use twopasses=1 option of this mangler. In that case, you won't need to pass ..,countsfile=a-file-with-counts,statefile=a-file-with-state options to the mangler - it will maintain counts file and state file in temporary files.

By default each symbol name is obfuscated to the unique, but random identifier of the length corresponding to the number of occurencies of the given symbol. That randomness of identifier can be disabled by passing value 0 for parameter dontshuffle - this will force e.g. first symbol in the first source file of the project to always be obfuscated to the name a (provided there is no exception with the same name).

It's possible to specify a set of characters that can be used for resultant symbol names by the use of spec option - e.g. one can make code very hard to analyze without modification by asking to use only symbols I and l for names of symbols - that will produce symbols like IllII or IIlIIl which look very similar in the most fonts (but of course this won't result in smallest output). The use of this option makes shortest obfuscator a reliable version of combs obfuscator for multi-module projects, since it eliminates a chance for a case when two different symbols in two different modules (in which only one of the symbols is used) getting replaced with the same resultant symbol (which is possible in theory, but has a very small possibility).

Options:

countsfile: Location of the countsfile - the file containing use counts for all symbols.
countupdate: Selects the mode of obfuscator - gathering symbol use counts (if value is 1) or obfuscating (value is 0). Default value is 0.
statefile: Specifies the name of the file with the state information used internally by obfuscator when it's in obfuscation mode.
dontshuffle: Instructs not to select random name of the given length as obfuscated symbol name, but to select the next one by alphabet not being an exception.
minlen: Instructs the minimal length of resultant symbol name. Default value is 1.
twopasses: Passing 1 to this option will force JavaScript Obfuscator to make two temporary files and internally pass them to statefile and countsfile options; first making a pass with countsupdate set to 1, and then making a pass with h countsupdate set to 0. So it obviates the need to call JavaScript Obfuscator manually two times. It will protect your entire project in one invokation of JavaScript Obfuscator. This option can't be used if you need to update and then reprotect only one file in your project, without re-protecting all other files.
spec: The value of this option instructs which characters can be used for generating names of symbols, the value should either be string that is a concatenation of all characters possible in the resultant symbol name, e.g. Il (that will produce symbols like IllII or IIlIIl) or OQ (that will produce symbols like OQOOQQ or QOOQQO), or a couple of such strings separated by colon, in which case a string before the colon specifies characters that can be used for leading symbol's character, and string after the colon specifies characters that can be used for all characters of the symbol except the first (the leading) - e.g. lI:lI1 (that will produce symbols like I1lII1 or lI1IIl1) or O:O0. The recommended values are lI, O:O0 and lI:lI1. The use of this option makes shortest obfuscator a reliable version of combs obfuscator for multi-module projects. If this option is not specified, it's assumed that all characters allowed for JavaScript language can form a resultant symbol name.

-n = obfuscators for numeric constants

There is only one non-trivial obfuscator for numeric constants currently - sum3. It's the default.

obfuscator none

Selecting this obfuscator will keep numbers unchanged.

obfuscator sum3

This obfuscator replaces the constant value with an arithmetic expression consisting of addition and substraction operations on either 3 constant numeric values (in case no asserters were enabled) or 2 constant numeric values and 1 constant variable (in case some asserters were enabled - please note that asserters are not supported in Trial version of the Product), which are represented as decimial and hexadecimial values (their radixes can be changed by altering format option). For different occurencies of the same constant numeric values, the choice is provided between using the same values used in expressions, or using 2 random values and one computed - this is controlled using const option. If you wish to make analysis of the differencies between revisions of your software more difficult, you should request the use of 2 random values and one computed in the expression - this way after each obfuscation each obfuscated file will differ from the previous run of obfuscator. This is the default obfuscator (in fact it's the only non-trvial one for numeric constants).

Options:

const: Specifies whether for the same numeric constant the obfuscation should produce different substitution expression (the value for the option is 0) or same expressuib (the value for the option is 1). Default value is 0.
format: Specifies the sprintf format string for the obfuscated substitutor. The default value is (0x%04x+% 4d-0x%04x).
format_var: Specifies the sprintf format string for the obfuscated substitutor in case a variable and 2 constants are used. The default value is (0x%04x+% 4d-%s).
var_use_ratio: In case some asserters were enabled, specifies the ratio of occurencies of expressions that involve variables compared to all numeric constants occured in the source code. E.g. if you wish that half of the numeric constants in your code referenced variables, you should set the value of this parameter to 0.5. It's not recommended to set this parameter to 0 for obvious reasons. The expressions in the code use references to variables, the bigger code is (expression with reference to variable is larger than expression without them by about 7-9 bytes). The default value is 0.25.

-s = obfuscators for string constants

These make constant strings more difficult to read. The default string obfuscator is hexchar. The default string obfuscator is none - that is, strings are not mangled at all.

obfuscator none

Selecting this obfuscator will keep strings unchanged.

obfuscator hexchar

This obfuscator substitutes each character of the string with reverse slash and it's code, by default in hexadecimial notation - e.g. string ``abc'' is substituted with ``\x61\x62\x63''.

format: Specifies the sprintf format string for each character's substitutor. The default value is '\\x%x'.

obfuscator list4chr

This obfuscator substitutes a string with the join(``'',list_of_expressions_evaluating_to_characters). The list_of_expressions_evaluating_to_characters is inline list of expressions that evaluate to individual characters. Each item in the list corresponds to the character of the string being obfuscated. Each character is created by composing a character with code computed as numeric expression that is produced using obfuscator for numeric constants; the parameters for this obfuscator are passed using -c option and have the same meaning as parameters to the obfuscator for numeric constants passed using -n option. The default value of parameter for the -c option is the same as for -n. The list4chr obfuscator is designed in order to make automatic deobfuscation of string constants someone may like to implement more complicated.

-c = obfuscator for character codes

Please read the description of the list4chr obfuscator for string codes (a previous paragraph). none obfuscator will not obfuscate character codes at all (but the string will still be unreadable).

-S server-mode-params

Specify options for server mode backends. The argument is server-specification, that has the following syntax:

server-backend-title[,option=value]..

There are several types of backends. The backend is selected by server-backend-title. Each backend can have options that alter its behaviour, in order to specify them the comma separated option=value pairs may follow server-backend-title after a comma.

There is a special backend with title none available - it doesn't perform any action other than processing selected input file (i.e. it doesn't have any server behaviour).

When non-default backend is used, JavaScript Obfuscator waits for input coming from a backend-specific source, processes input according to commandline options given to it when JavaScript Obfuscator was started (this means that the same set of exceptions and other processing options will be used for all supplied inputs), and returns the result of processing in the backend-specific way to the client (or stores them somewhere).

Here is a list of server-backend-titles, with the options they support.

none

When it's selected, JavaScript Obfuscator will read input file from stdin or from file whose name is passed as a commandline argument, and will produce output on stdout or to the file specified with -o option. This server mode has no options. This is default server mode.

multifile

This server mode allows to process several files with the same set of commandline options at once. The names of files are passed as commandline arguments of JavaScript Obfuscator or via filelist parameter; they may be located in different directories. The name of the output directory is specified with outdir option of this server mode; if filenames to process are absolute pathnames it's necessary to specify input directory relative to which output filenames will be computed by the use of option indir. If filenames to process are relative names, it's assumed that current directory is input directory relative to which output filenames will be computed. All necessary output subdirectories will automatically be created.

Example:

The following commandline fragments:

    -S multifile,outdir=/home/user/prj1/out,indir=/home/user/prj1/in         /home/user/prj1/in/file1.js /home/user/prj1/in/file2.js         /home/user/prj1/in/subdir1/file3.js

and

    -S multifile,outdir=/home/user/prj1/out         file1.js file2.js subdir1/file3.js

are equivalent if current directory is /home/user/prj1/in. So at first JavaScript Obfuscator will create /home/user/prj1/out/subdir1 (if absent), and will put protected version of file1.js to /home/user/prj1/out/file1.js, file2.js to /home/user/prj1/out/file2.js and subdir1/file3.js to /home/user/prj1/out/subdir1/file3.js.

Options supported:

outdir: This option is required; it specifies the output directory.
indir: This option specifies base input directory used to compute input file names (see example above); specifying this option is not necessary if all input filenames specified are relative.
filelist: This option specifies name of file that contains filenames to process, one per line. Filenames should be relative to the directory specified by indir parameter. This is not mandatory option - if it's not specified, names of files to process are taken from the command line.

backend unix-socket

When this backend is selected, JavaScript Obfuscator starts accepting connections on the AF_UNIX domain socket with name specified with option socketname using a special protocol. The clients connect to it using that socket, tell the input length using string produced by printf format ``% 9d\n'', and then write the input to be processed, JavaScript Obfuscator processes it using the options specified on the commandline when it was invoked, and returns the result of processing to the client.

This server mode is supported only on unix-like platforms (e.g. Unix, Linux, FreeBSD, MacOS X). It's not supported on Windows.

Options:

socketname: Specifies the filename of the socket to listed for client requests on. The default value is /tmp/obfus-server-socket.

backend tcp-socket

When this backend is selected, JavaScript Obfuscator starts accepting connections on the TCP socket at port and ip address specified with options port and ip respectively using a special protocol. The clients connect to it using, tell the input length using string produced by printf format ``% 9d\n'', and then write the input to be processed, JavaScript Obfuscator processes it using the options specified on the commandline when it was invoked, and returns the result of processing to the client.

Options:

port: Specifies the port to listen for incoming connections. The default value is 7654.
ip: Specifies the IP address to listen for incoming connections. Use '0.0.0.0' to listen on all IP addresses. The default value is 127.0.0.1 (i.e. listening only on loopback interface is default behaviour).

-T time-asserter-params

-H hostname-asserter-params

-G generic-asserter-params

Specify options for asserters of each type (not available in Trial version of the product). The argument is asserter-specification, that has the following syntax:

asserter-title[,option=value]..

There are several subtypes of asserters for each type. The subtype is selected by asserter-title. Each asserter can have options that alter its behaviour, in order to specify them the comma separated option=value pairs may follow asserter-title after a comma.

For each type of asserters a special asserter with title none is available - it doesn't perform any action.

Here is a list of asserter-titles for each type of the asserters, with the options they support.

-T = time asserters

Time asserters insure that some condition about the point of time the script was started at is true.

asserter expire

This asserter insures that current date and time is less than one specified via whenexpires option. There way used to acquire current date and time is specified via source option. If condition is violated, the code finishes execution after performing all other actions requested. The warning, specified via option onviolated-message will be printed if value of option onviolated-warn is 1.

Options:

whenexpires

Specifies the date and time after which program should stop working. The format of this parameter can be either number of seconds since 1 Jan 1970, or human representation of the absolute date and time like 20 Apr 2004 15:43 or 2004/4/20 15:43, or relative date and time of the form ``now + count units time-spec'' like ``now + 2 weeks 9:00'' (i.e. any format Perl module Time::ParseDate recognizes). If the value is a string 0, then the asserter is disabled. Default value is 0.

onviolated-warn

If 1, directs message specified via onviolated-message to be printed. Default value is 0.

onviolated-message

Specifies the message to be printed in case value of onviolated-warn is 1. The trailing newline will be automatically appended. Escape sequences are allowed. Please be sure to quote the message properly in order the shell passed the message as a single string. Default value is ``The script has expired, please contact webmaster.''.

source

Specifies the source of information about current time. The possible options are:

date.gettime: The getTime() method of the default-constructed Date object is used. This is the default method.
document.lastModified: The Last-Modified HTTP header for the document script is running in is used as a source of information about current time. This means that web server should emit current time and date when generating the documents into which protected scripts are integrated. On some ancient browsers this method of getting current time is unavailable if browser is running under non-english environment. In case this method of getting current time is not available, the fallback - using the default source - is used.

asserter expire-ASP

Same as the expire asserter, but targeted for JavaScript scripts inside ASP files. In case of violation of licensing conditions the warning about program expiration is output to the client, and the page processing is aborted after that.

asserter expire.NET-console

Same as the expire asserter, but targeted for JavaScript programs for the .NET platform. The warning about program expiration is printed using print() function, and program is terminated after that.

asserter expire.NET-gui

Same as the expire asserter, but targeted for JavaScript programs for the .NET platform. The warning about program expiration is shown in MessageBox, and the program is terminated after that.

-H = hostname asserters

Hostname asserters insure that some condition about the name of the host from which the document the script is inside was got by web browser satisfies certain conditions. In case the conditions are not met, the script is terminated. If parameter onviolated-warn is 1, the message specified by parameter onviolated-message is displayed.

All of these asserters support the same set of parameters:

matches

The string interpreted differently by each asserter, it's a host name for single-host asserter, a plus-separated list of allowed host suffixes for hosttails asserter or a regular expression to which hostname should match for hostregex asserter. In all cases hostnames should be assumed in lowercase. See more details about treatment of hostname below. Default value is localhost.

onviolated-warn

If 1, the message specified with parameter onviolated-message is printed before program is terminated in case condition about hostname is not met. Default value is 0.

onviolated-message

Specifies the message to be printed in case condition about hostname is not met. The trailing newline will be automatically appended. Escape sequences are allowed. Please be sure to quote the message properly in order the shell passed the message as a single string. Default value is ``The script is not licensed to be run from this server.''

source

The source of information about server's hostname.

The following sources of information are supported:

document.domain: The value of document.domain is used as a hostname. This is the default method.
window.location.host: The value of window.location.host is used as a hostname of a host the document came from.
env_http_host: The value returned by Request.ServerVariables(``HTTP_HOST'') is used as host name. It's the default for all host asserters with names ending in ASP. It's applicable only for asserters with names ending in ASP.
env_server_name: The value returned by Request.ServerVariables(``SERVER_NAME'') is used as host name. It's applicable only for asserters with names ending in ASP.
.NET-machineName: The value of Environment.MachineName is used as a hostname. Can be used only for JavaScript for .NET programs. It's the default for all host asserters with names containing .NET.

Default value is document.domain.

All hostname asserters differ only in treatment of the parameter matches. The following hostname asserters are supported:

single-host

The parameter matches is a single name of host with domain part, e.g. uk3.valuehost.com.

hosttails

The parameter matches is a +-separated list of hostname tails of host to match, e.g. valuehost.com+valuehost.co.uk. Hosts with names uk3.valuehost.com and support.valuehost.co.uk and even ad.bestvaluehost.com will be considered as matching by this asserter.

hostregex

The parameter matches is a regular expression that host name should match. Don't forget to insert acnhors ^ and $ around it - they won't be automatically appended and prepended. Don't forget to quote shell special characters like * and $ (or just enclose entire parameter inside single quotes if on unix). E.g. the value [.]valuehost[.] of parameter matches will make hosts with names www.valuehost.com and support.valuehost.co.uk as matching by this asserter, and host with name www.bestvaluehost.com and www.valuehosters.com won't be considered matching.

single-host-ASP

hosttails-ASP

hostregex-ASP

Same as the asserters with titles without -ASP suffix, with same options and semantics, but targeted for JavaScript code inside ASP files. The warning about program expiration is printed to client and request processing is stopped in case licensing conditions were violated.

Only timesources env_http_host and env_server_name are allowed for these asserters.

single-host-.NET-console

hosttails-.NET-console

hostregex-.NET-console

Same as the asserters with titles without -.NET-console suffix, with same options and semantics, but targeted for JavaScript programs for the .NET platform. The warning about program expiration is printed using print() function, and then the program is terminated.

single-host-.NET-gui

hosttails-.NET-gui

hostregex-.NET-gui

Same as the asserters with titles without -.NET-gui suffix, with same options and semantics, but targeted for JavaScript programs for the .NET platform. The warning about program expiration is shown in MessageBox, and then the program is terminated.

-G = generic asserters

Generic asserters allow to insert custom checks and actions in the highly-protected block of code. There are no requirement on the code at all, no parsing of it is performed.

asserter from-string: This asserter has only one parameter - code - a string of custom code.
asserter from-file: This asserter takes the code from file specified via filename parameter.

It's possible to use fake generic asserters with code ' ' (i.e. single space character) to make the analysis of the program more complex (since in case any asserter is used, some fraction of numeric expressions will be turned to arithmetic expressions involving constant variables initialized in the encoded block). This trick (passing -G from-string,code=' ') will make custom decompiler one will have to write to be able to analyze the code much more complex.

In order to report violation of licensing conditions, user's code to be executed depends on the target platform.

For client-side Web scripts, the code should be:

 eval("'");while(1) {;}

For .NET environment, the code should be

 Environment.Exit(102);

For embedded .NET environment, the code should be

 __stunnix_com_asserters_result=1;throw(1);

The code of all other statements applicable for a target platform should be executed as well, e.g. Response.End() for ASP.

-O profile-params

Tune the behaviour of the JavaScript Obfuscator for some specific dialect or environment.

The argument is profile-params, that has the following syntax:

profile-name[,option=value]..

There are several profiles available. The profile is selected by profile-name. Each profile can have options that alter its behaviour, in order to specify them the comma separated option=value pairs may follow profile-name after a comma.

The following values for profile-name are available:

default
html: Tune JavaScript Obfuscator for pure JavaScript language used in clientside scripts for WWW, preloading appropriate exceptions. The names of these profiles are interchangable.
wsc: This profile is designed for scripts for Windows Scripting Components framework; it automatically loads necesarry exceptions.
wsh: This profile is designed for scripts for Windows Scripting Host framework; it automatically loads necesarry exceptions.
asp: Tune JavaScript Obfuscator for pure JavaScript language used in serverside ASP scripts, preloading appropriate exceptions, including exceptions for MS ADO.
pure
javascript: Tune JavaScript Obfuscator for pure JavaScript language, without any exceptions preloaded. The names of these profiles are interchangable. These are default profiles.
ecmascript: Tune JavaScript Obfuscator for EcmaScript programs. This allows encoding of scripting languages based directly on EcmaScript specification to function correctly, and also automatically loads list of exceptions specific to EcmaScript. Do not use this profile if using JavaScript Obfuscator for JavaScript programs used in .NET environment, use profiles javascript.NET or javascript.NET-embedded instead.
javascript.NET: Tune JavaScript Obfuscator for JavaScript language used in .NET environment. This allows license conditions asserters to function properly in JavaScript programs for .NET environment processed with JavaScript Obfuscator.
javascript.NET-embedded: Tune JavaScript Obfuscator for JavaScript language used in .NET environment for scripting applications. This is basically the same as javascript.NET profile, with only difference in behaviour in case license conditions are violated - using profile javascript.NET-embedded application won't be terminated by a call to Environment.Exit(), but will be terminated using other means.

The profile with name default is the default profile.

All profiles have the following options (specified in the way options for manglers and extractors are specified):

handle-dynamic-scripts: Specifies whether dynamic JavaScript code (the code generated on the fly) should be obfuscated. See the description of the option with the same name for asp extractor.
dynamic-scripts-by: Specifies names of objects and methods whoose arguments should be scanned for dynamic JavaScript code. See the description of the option with the same name for asp extractor.

-E extractor-params

Specify options for extractors. The argument is extractor-specification, that has the following syntax:

extractor-title[,option=value]..

There are several types of extractors. The extractor is selected by extractor-title. Each extractor can have options that alter its behaviour, in order to specify them the comma separated option=value pairs may follow extractor-title after a comma.

There is a special extractor with title none available - when it's used, it's assumed that the input is raw JavaScript code (i.e. not embedded into any envelopes and not surrounded by any prefixes and suffixes).

When non-default extractor is used, JavaScript Obfuscator extracts JavaScript code from the input using extractor-specific logic, processes the extracted JavaScript code (i.e. obfuscates and/or encodes it), and merges the processed code into the original envelope/markup using extractor-specific logic.

Here is a list of extractor-titles, with the options they support.

extractor none

When this extractor is selected, it's assumed that the input is raw JavaScript code (i.e. not embedded into any envelopes and not surrounded by any prefixes).

This extractor doesn't have any options. This is the default extractor.

extractor html

When this extractor is selected, JavaScript Obfuscator assumes that input is html file with JavaScript code embedded into it. This JavaScript code is processed (obfuscated/encoded) in place according to all commandline options given, and then it's merged back into original html file, replacing original fragments with obfuscated code.

The html file needn't be valid one with respect to HTML DTDs. Names of elements and attributes that are examined by the JavaScript Obfuscator (e.g. SCRIPT, onclick or language) can be written in any case, and even in the mixed ones.

Code in the event handlers (e.g. specified using attribute onsubmit) is processed too.

Scripts inside constructs <SCRIPT></SCRIPT> and <SCRIPT></SCRIPT> are supported.

Scripts declared as written in the JavaScript using the attribute LANGUAGE are processed automatically. Scripts without any language specified are processed conditionally on the value of the option untyped-script-supported. Scripts declared as written in the language different from JavaScript using the attribute LANGUAGE are not processed at all (i.e. html source file can mix scripts in different languages).

Emebdded ASP, PHP and SSI fragments are handled correctly, independant of their location - inside SCRIPT element (even inside string constants in the scripts), inside body of the event handlers or inside list of attributes of any html element.

Options:

untyped-script-supported: When this option has value 1, all scripts inside SCRIPT tag without language specified using language attribute are also processed. The default value is 1.
simple-jsp-support: Treat string argument of out.println() in JSPs as client-side JavaScript code, and obfuscate JavaScript inside string constants. The default value is 0.
do-not-encode-fragments: When this option has value 0, all scripts inside SCRIPT tag are encoded; if it has value 1, scripts are not encoded. Handlers (scripts used inside onXXX attributes, e.g. onsubmit) are not encoded in any case. The default value is 1.
include-decoder-only-once: If the value of this option is 0, then decoder needs to be appended after each encoded block. The decoder won't be appended if any asserter is used. If the code being encoded is bodies of the functions, then this option should have value 0. If the code being encoded is top-level code, then this option should have value 1. The default value for this option is 0.
attributes-list-file: Specifies the file with names of attributes in which scripts should be obfuscated. By default contains name of file with names of all attributes that can contain scripts according to HTML 4.01 specification.
skip-script-mark-attibute: Specifies name of the attribute value of which indicates whether content of the SCRIPT element to which it's applied should be ignored for processing by JavaScript Obfuscator. If the value of attribute with that name is 1, then it's content is not processed by JavaScript Obfuscator. The default value for this option is stunnix-obfus-skip.
pack-html: Specifies whether html itself should be packed to as few lines as possible, by removing extra spaces and line breaks. Note, removing of html comments is controlled using remove-comments option. The default value for this option is 0.
charencode-html-text: Specifies whether all characters between tags are to be replaced with html entities, provided that option pack-html has value 1. The default value for this option is 0.
charencode-html-attrvals: Specifies whether characters in values of attributes are to be replaced with html entities, provided that option pack-html has value 1. The default value for this option is 0.
entities-percentage: Specifies the percentage of characters to be encoded as entities (whether encoding will be performed at all is determined by charencode-html-attrvals and charencode-html-attrvals options. It's recommended to keep value of this option below 100 since it when all characters are encoded, output looks less random. The default value for this option is 50.
transform-tagnames: Specifies how to transform tagnames (elemnt names). none means don't transform, tolower means lowercase them, toupper means uppercase them, mix means use random case for each of the characters, pairs means making each character with even index uppercase, and with odd index - lowercase. The default value for this option is none.
transform-attrnames: Specifies how to transform element names. none means don't transform, tolower means lowercase them, toupper means uppercase them, mix means use random case for each of the characters, pairs means making each character with even index uppercase, and with odd index - lowercase. The default value for this option is none.
remove-comments: Specifies whether html comments have to be removed. The default value for this option is 0.
no-code: Specifies whether to process any code in the file at all. The default value for this option is 0 (meaning that code should be handled).

extractor asp

When this extractor is selected, JavaScript Obfuscator assumes that input is ASP (Active Server Pages) file with JavaScript code embedded into it. This JavaScript code is processed (obfuscated/encoded) in place according to all commandline options given, and then it's merged back into original file, replacing original fragments with obfuscated code.

When this extractor is selected, exceptions for pre-defined ASP objects and their methods (e.g. Response, Request, etc) and their methods and properties are preloaded.

The asp file needn't be valid one with respect to HTML DTDs. Names of elements and attributes that are examined by the JavaScript Obfuscator (e.g. SCRIPT, runat or language) can be written in any case, and even in the mixed ones.

Scripts run at server and declared as written in the JavaScript using the attribute LANGUAGE are processed automatically. Scripts run at server and without any language specified are processed conditionally on the value of the option untyped-script-supported. Scripts declared as written in the language different from JavaScript using the attribute LANGUAGE are not processed at all (i.e. html source file can mix scripts in different languages).

Options:

untyped-script-supported: When this option has value 1, all scripts inside SCRIPT tag run at server without language specified using language attribute are also processed. The default value is 1.
do-not-encode-fragments: When this option has value 0, all scripts inside SCRIPT tag run at server are encoded; if it has value 1, scripts are not encoded. Code in fragments starting with <%= and with <%# is never encoded. The default value is 1.
include-decoder-only-once: If the value of this option is 0, then decoder needs to be appended after each encoded block. The decoder won't be appended if any asserter is used. If the code being encoded is bodies of the functions, then this option should have value 0. If the code being encoded is top-level code, then this option should have value 1. The default value for this option is 0.
handle-asp-fragments: Instructs whether to obfuscate/encode code between <% and %> (1 - obfuscate/encode, 0 - don't touch (i.e. process only scripts run at server)). Default value is 1.
skip-script-mark-attibute: Specifies name of the attribute value of which indicates whether content of the SCRIPT element to which it's applied should be ignored for processing by JavaScript Obfuscator. If the value of attribute with that name is 1, then it's content is not processed by JavaScript Obfuscator. The default value for this option is stunnix-obfus-skip.
pack-html: Specifies whether html itself should be packed to as few lines as possible, by removing extra spaces and line breaks. Note, removing of html comments is controlled using remove-comments option. The default value for this option is 0.
remove-comments: Specifies whether html comments have to be removed. The default value for this option is 0.
handle-dynamic-scripts: Specifies whether pieces of JavaScript code located inside statements of server-side language that output client-side JavaScript should be protected. The names of methods and objects whoose arguments are scanned for pieces of JavaScript are specified via dynamic-scripts-by option. The default value for this option is 0 (i.e. no dynamic scripts are recognized and processed).
dynamic-scripts-by: If option handle-dynamic-scripts has value 1, then the value of this option specifies list of method names (separated by plus sign) whoose arguments are treated as pieces of JavaScript code. It's possible to specify not only name of method, but also the name of object the method applies to - by specifying object name, the dot and the method name. E.g. the following value of the option - jsout.write+printdyncode - states that arguments of method or function named printdyncode and arguments of statements involving call of write method on jsout object will be treated as dynamic scripts and will be obfuscated. The default value is empty string.

extractor wsc

extractor wsh

These are two different extractors, wsc for scripts for Windows Scripting Components framework inside XML files, and wsh is Windows Scripting Host framework. When using them, you have to gather a list of exceptions from WSC/WSH files using utility gen-ident-from-html.pl shipped with JavaScript Obfuscator, to generate list of IDs used inside various elements describing names of symbols global to the scripts. Values of internalName attribute will be obfuscated in WSC files. These extractors have similar sets of options:

do-not-encode-fragments: When this option has value 0, all scripts inside SCRIPT tag run at server are encoded; if it has value 1, scripts are not encoded. The default value is 1.
include-decoder-only-once: If the value of this option is 0, then decoder needs to be appended after each encoded block. The default value for this option is 0.
skip-script-mark-attibute: Specifies name of the attribute value of which indicates whether content of the SCRIPT element to which it's applied should be ignored for processing by JavaScript Obfuscator. If the value of attribute with that name is 1, then it's content is not processed by JavaScript Obfuscator. The default value for this option is stunnix-obfus-skip.

extractor asp.NET

When this extractor is selected, JavaScript Obfuscator assumes that input is ASP.NET (Active Server Pages for .NET platform) file with JavaScript code embedded into it. This JavaScript code is processed (obfuscated/encoded) in place according to all commandline options given, and then it's merged back into original file, replacing original fragments with obfuscated code.

When this extractor is selected, exceptions for pre-defined ASP.NET objects and their methods (e.g. Response, Request, etc) and their methods and properties are preloaded.

The asp.NET file needn't be valid one with respect to HTML DTDs. Names of elements and attributes that are examined by the JavaScript Obfuscator (e.g. SCRIPT, runat, onserverclick or language) can be written in any case, and even in the mixed ones.

Scripts inside constructs <SCRIPT></SCRIPT> and <SCRIPT></SCRIPT> are supported, provided the SCRIPT element has attribute runat with value server specified. Also code inside <% and %> (including proper support for code fragments begining with <%= and <%# ) is processed. Also code in corresponding attributes of serverside objects (ones declared with runat=server) - e.g. onserverclick is processed.

Options:

untyped-script-supported: When this option has value 1, all scripts inside SCRIPT tag run at server without language specified using language attribute are also processed. The default value is 1.
do-not-encode-fragments: When this option has value 0, all scripts inside SCRIPT tag run at server are encoded; if it has value 1, scripts are not encoded. Code in fragments starting with <%= and with <%# is never encoded. The default value is 1.
include-decoder-only-once: If the value of this option is 0, then decoder needs to be appended after each encoded block. The decoder won't be appended if any asserter is used. If the code being encoded is bodies of the functions, then this option should have value 0. If the code being encoded is top-level code, then this option should have value 1. The default value for this option is 0.
handle-asp-fragments: Instructs whether to obfuscate/encode code between <% and %> (1 - obfuscate/encode, 0 - don't touch (i.e. process only scripts run at server and in attributes specifying handlers)). Default value is 1.
attributes-list-file: Specifies the file with names of attributes in which scripts should be obfuscated. By default contains name of file with names of all attributes that can contain serverside scripts according to ASP.NET control reference (includes onserverclick and onserverchange currently).
skip-script-mark-attibute: Specifies name of the attribute value of which indicates whether content of the SCRIPT element to which it's applied should be ignored for processing by JavaScript Obfuscator. If the value of attribute with that name is 1, then it's content is not processed by JavaScript Obfuscator. The default value for this option is stunnix-obfus-skip.
pack-html: Specifies whether html itself should be packed to as few lines as possible, by removing extra spaces and line breaks. Note, removing of html comments is controlled using remove-comments option. The default value for this option is 0.
remove-comments: Specifies whether html comments have to be removed. The default value for this option is 0.
handle-dynamic-scripts: See the description of the option with the same name for asp extractor.
dynamic-scripts-by: See the description of the option with the same name for asp extractor.

extractor code

This extractor allows to support partial encoding of the code - i.e. selectively applying encoding to arbtirary number of blocks of orignal source code. It assumes that its input is usual JavaScript with two types of special comments embedded, /*STUNNIX-OBFUS-ENCODED-BEGIN*/ and /*STUNNIX-OBFUS-ENCODED-END*/. Everything between /*STUNNIX-OBFUS-ENCODED-BEGIN*/ and /*STUNNIX-OBFUS-ENCODED-END*/ will be encoded, everything outside of them won't be encoded. This extractor has only one option - include-decoder-only-once, see its description in the description of obfuscator html.

extractor delimited

This extractor allows to protect JavaScript code inside file with any syntax, provided that pieces of JavaScript code are surrounded by special markers. Arbitrary strings, not containing newlines, can be used as those markers. Lists of markers, one per line, are loaded from files. List of strings that denote start of JavaScript code are loaded from file specified using file-with-start-delimiters option. List of strings that denote end of JavaScript code are loaded from file specified using file-with-end-delimiters option. It's possible to encode each piece of JavaScript by setting value of option do-not-encode-fragments to 0. If the file has XML syntax (so XML special characters like &, < and > are quoted using &, < or > entities, set the value of option xml-escape-code to 1.

Options are:

do-not-encode-fragments: When this option has value 0, all pieces of JavaScript are encoded. If it has value 1, scripts are not encoded. The default value is 1.
xml-escape-code: If the value of this option is 1, XML entities like & are converted to the real characters before getting to the JavaScript parser; after obfuscation and possible encoding, those XML-unsafe characters are converted back to entities. The default value for this option is 0.
file-with-start-delimiters
file-with-end-delimiters: These two options specify names of files with delimiters, specified one per line. Any of the delimiters can mark the begining of JavaScript code, and any of delimiters from file specified by file-with-end-delimiters can terminate piece of JavaScript code. The number of lines in those 2 files need not be the same. These 2 options are required to be set - there are no default values for them.

extractor rawXsp

This extractor allows to protect JavaScript code inside files, that are basically raw JavaScript files, but contain ASP, JSP, PHP, ASP.NET or SSI blocks. Don't confuse it with HTML where script is surrounded by html markup, and is enclosed by SCRIPT tags - use html extractor in that case. Use it for raw JavaScript generated by server-side language only.

This extractor has no options.

extractor othercode

This extractor allows to protect JavaScript inside string constants of some other programming language (e.g. Java or C# or C++) - called ``outer'' language for short. The outer language won't be touched at all. This extractor has only one option - dynamic-scripts-by, see its description in the description of obfuscator html. E.g. if you need to obfuscate JavaScript inside arguments of the functions Outstream.MyPrint and OutStream.MyWrite in the java, you will have to add:


    -E othercode,dynamic-scripts-by=Outstream.MyPrint+OutStream.MyWrite

to the commandline of the obfuscator. The JavaScript needs to be located inside string constant. String constant may use ' or `` for delimiter (depending on the outer language) and even can contain C-style quoting using backslashes.

RETURN VALUE

In case of an error, the exit code will be non-zero, otherwise the exit code will be zero.

DIAGNOSTICS

On successful processing of the file its obfuscated and/or encoded version will be printed to stdout or saved to file specifed with -o commandline option. The processing will stop if there is a syntax error in the file being obfuscated or in the file it uses - in that case location and details of syntax error will be printed to stderr.

EXAMPLES

The following commandline obfuscates and encodes file blah.js using default parameters and exceptions from file named ./excepts, writing obfuscated and encoded version to oblah.js:

    js-obfus blah.js -o oblah.js -x ./excepts

The following commandline is recommended way of obfuscating file blah.js for shipping using default parameters and exceptions from file named ./excepts, writing obfuscated and encoded version to oblah.js (the main difference from previous example is passing the value of the seed parameter for obfuscator routine for symbol names):

    js-obfus blah.js -o oblah.js -x ./excepts -i md5,seed=SomeRandomString

The following commandline is a recommended for producing the mildly-obfuscated non-encoded version of the blah.js that is ideal for testing whether the obfuscated code has no problems like use of undefined symbols (that may arise due to insufficiently complete list of exceptions in file ./excepts) :

    js-obfus blah.js -e 0 -o oblah.js -x ./excepts -n none -s none -i prefix,str=ZZZ

The following commandlines are a sample of passing same set values for all options to the md5 obfuscator routine for symbol names. It obfuscates and encodes file blah.js, writing obfuscated and encoded version of the file to oblah.js:

    js-obfus blah.js -o oblah.js -i md5,seed=57823,prefix=p,len=5
    js-obfus blah.js -o oblah.js -i 'md5,prefix=p, seed=57823 , len=5'

The following example obfuscates and encodes file blah.js, writing obfuscated and encoded version of the file to oblah.js, with embedding code for license checking that allows the code to be executed when document script is integrated into is served from servers with names ending .site.com or from site.com itself till 28 April 2005; upon expiration of the code default message is printed:

    js-obfus blah.js -o oblah.js 
        -T 'expire,whenexpires=28 April 2005,onviolated-warn=1' 
        -H hosttails,matches=site.com+.site.com,onviolated-warn=1

FILES

It's possible to store the default commandline options in the globally-visible file $instroot/lib/js-obfus/js-obfus-settings.pl (where $instroot is a directory in which the JavaScript Obfuscator package was installed to) which is a Perl module. This file defines one sub cmnargs that should return a list of options to be prepended to actual commandline the js-obfus, thus allowing to store ``persistent settings'' for js-obfus.

NOTES

In most cases, once properly prepared for obfuscation, obfuscated version of the code should work the same as non-obfuscated. After fixing the issues with incomplete set of exceptions, it's recommended to check whether ofbuscated code behaves exactly the same as original - by using pre-existing testsuite or checking functionality manually.

If some obfuscated code is syntaxically correct but works differently than original version , obfuscate it without encoding and string, integer and ident mangling as following:

    js-obfus -i none -s none -n none -jam 1 -e 0

Then try to run it again. If it still does not work correctly, find the source file which is guilty by replacing each of the obfuscated files with original ones one by one. After you have found the file that contains the problem, append the definitions of all functions from the source file to that target file and by temporary renaming function names in the appended part to something else (e.g. by suffixing the names with '1' or 'blah') you will be able to find the function that is guilty. Same process can be applied to the blocks in the guilty function too (just replace obfuscated parts with source parts) to find out which part of the obfuscate function is misbehaving.

Having found the function block that misbehaves, that block should be modified in order the obfuscated version to have the same functionality as original code.