Thursday, April 12, 2007

HOW TO BECOME ELITE HACKER

Looking for advice on learning to crack passwords, sabotage systems, mangle websites, write viruses, and plant Trojan horses? You came to the wrong place. I'm not that kind of hacker.

Looking for advice on how to learn the guts and bowels of a system or network, get inside it, and become a real expert? Maybe I can help there. How you use this knowledge is up to you. I hope you'll use it to contribute to computer science and hacking (in its good sense), not to become a cracker or vandal.

This little essay is basically the answers to all the emails I get asking how to become a hacker. It's not a tutorial in and of itself. It's certainly not a guaranteed success. Just give it a try and see what happens. That said, here's where to start:

Be curious
Take things apart. Look under the hood. Dig through your system directories and see what's in there. View the files with hex editors. Look inside your computer. Wander around computer stores and look at what's there.

Read everything in sight
If you can afford it, buy lots of books. If you can't, spend time in libraries and online. Borrow books from friends. Go through tutorials. Read the help files on your system. If you're using Unix/Linux, read the man files. Check out the local college bookstores and libraries. And as you're reading, try things (see next paragraph).

Experiment
Don't be afraid to change things, just to see what'll happen. Do this long enough, of course, and you'll wipe out your system (see next paragraph), but that's part of becoming a hacker. Try command options and switches you've never tried before. Look for option menus on programs and see what they can do. In Windows, tweak your registry and see what happens. Change settings in .INI files. In Unix, dig around in the directories where you don't normally go. On the Macintosh, play around in the system folder.

Make backups
If you start mucking around with system files, registries, password files, and such, you will eventually destroy your system. Have a backup ready. If you can afford it, have a system you use just for experimenting, ready to reload on a moment's notice, and do your serious work (or serious gaming!) on a different computer.

Don't limit yourself
Who says a computer or network is the only place to hack? Take apart your telephone. Figure out your television (careful of the high voltage around the picture tube - if you fry yourself, it's not my fault) and VCR. Figure out how closed captioning works (that was a plug for my CaptionCentral.com Web site). Take apart your printer. Pick up the latest issues of Nuts & Volts and Midnight Engineer (you've obviously made a good start if you're reading Blacklisted! 411). Take apart the locks on your doors. Figure out how your radio works. Be insatiably curious and read voraciously. There are groups you can learn from. There are whole Web sites devoted to hacking TiVo units, for example.

Get some real tools
You can't cut a board in half with a screwdriver. Well, maybe you can, but it'll take a long time. Dig around and find the proper tools for the operating systems you're using. They're out there on the Web. You can get some pretty good stuff as shareware or freeware (especially on Linux). The serious power tools often cost serious money. What kinds of tools? Hex file editors. Snoopers that analyze system messages and network traffic. Compilers and APIs for programming. Scripting tools. Disk editors/formatters. Disassemblers. When you get good, write some of your own.

Learn to program
If you want to be a hacker, you're going to have to learn to program. The easiest way to start depends on the operating system you're using. The choice of language is very individual. It's almost a religious thing. Suggest a programming language to a beginner, and someone will disagree. Heck, you'll probably get flamed for it in a newsgroup. In Unix, I'd suggest getting started with Perl. Buy a copy of the camel book (Programming Perl) and the llama book (Learning Perl). You'll have the fundamentals of programming really fast! The best part is that the language itself is free. In Windows, you can get started quickly using a visual development environment like Visual Basic or Java. No matter what the system, if you want to get serious, you'll eventually need to learn C (or C++ or C# or some other variant). Real hackers know more than one programming language, anyway, because no one language is right for every task.

Learn to type
Hackers spend a lot of time at their keyboards. I type 90+ wpm (according to the Mavis Beacon typing tutor). HackingWiz (of hackers.com and Hacker's Haven BBS fame) says he can type 140+ wpm. The typing tutor may be boring, but it pays off.

Use real operating systems
Windows 95/98/Me is a shell on top of a 32-bit patch to a 16-bit DOS. Get some real operating systems (Linux, Windows NT, Mac OS, OS/2...) and learn them. You can't call yourself a linguist if you only know one language, and you certainly can't call yourself a hacker if you only know one OS. Linux is a hacker's dream. All the source code is freely available. Play with it, analyze it, learn it. Eventually, perhaps you can make a contribution to Linux yourself. Who knows, you might even have a chance to write your own OS.

Talk to people
It's hard to learn in a vacuum. Take classes. Join users groups or computer clubs. Talk to people on IRC or newsgroups or Web boards until you find people to learn with. That can take a while. Every third message on newsgroups like alt.hack* is "teach me to hack." Sigh. The best way to be accepted in any group is to contribute something. Share what you learn, and others will share with you.

Do some projects
It's important to pick some projects and work until you've finished them. Learning comes from doing, and you must follow the project through start to finish to really understand it. Start really simple. Make an icon. Customize your system (the startup screen on Win95, or the prompt on Unix). Make a script that performs some common operation. Write a program that manipulates a file (try encrypting something).

Learn to really use the Internet
Start with the Web. Read the help for the search engines. Learn how to use Boolean searches. Build up an awesome set of bookmarks. Then move on to other Internet resources. Get on Usenet. Find some underground BBSs. Get on IRC. You'll find useful information in the strangest places. Get to the point where you can answer your own questions. It's a whole lot faster than plastering them all over various newsgroups and waiting for a serious answer.

Once you've gone through these steps, go out and contribute something. The Internet was built by hackers. Linux was built by hackers. Usenet was built by hackers. Sendmail was built by hackers. Be one of the hackers that builds something.

LEARN HOW TO BE A ELITE HACKER

The hacker attitude is vital, but skills are even more vital. Attitude is no substitute for competence, and there's a certain basic toolkit of skills which you have to have before any hacker will dream of calling you one.

This toolkit changes slowly over time as technology creates new skills and makes old ones obsolete. For example, it used to include programming in machine language, and didn't until recently involve HTML. But right now it pretty clearly includes the following:

1. Learn how to program.
This, of course, is the fundamental hacking skill. If you don't know any computer languages, I recommend starting with Python. It is cleanly designed, well documented, and relatively kind to beginners. Despite being a good first language, it is not just a toy; it is very powerful and flexible and well suited for large projects. I have written a more detailed evaluation of Python. Good tutorials are available at the Python web site.

Java is also a good language for learning to program in. It is more difficult than Python, but produces faster code than Python. I think it makes an excellent second language. (There used to be a problem with Java because it was proprietary, but Sun is remedying that and the difficuties should entirely vanish with the final code drop in early 2007.)

But be aware that you won't reach the skill level of a hacker or even merely a programmer if you only know one or two languages — you need to learn how to think about programming problems in a general way, independent of any one language. To be a real hacker, you need to get to the point where you can learn a new language in days by relating what's in the manual to what you already know. This means you should learn several very different languages.

If you get into serious programming, you will have to learn C, the core language of Unix. C++ is very closely related to C; if you know one, learning the other will not be difficult. Neither language is a good one to try learning as your first, however. And, actually, the more you can avoid programming in C the more productive you will be.

C is very efficient, and very sparing of your machine's resources. Unfortunately, C gets that efficiency by requiring you to do a lot of low-level management of resources (like memory) by hand. All that low-level code is complex and bug-prone, and will soak up huge amounts of your time on debugging. With today's machines as powerful as they are, this is usually a bad tradeoff — it's smarter to use a language that uses the machine's time less efficiently, but your time much more efficiently. Thus, Python.

Other languages of particular importance to hackers include Perl and LISP. Perl is worth learning for practical reasons; it's very widely used for active web pages and system administration, so that even if you never write Perl you should learn to read it. Many people use Perl in the way I suggest you should use Python, to avoid C programming on jobs that don't require C's machine efficiency. You will need to be able to understand their code.

LISP is worth learning for a different reason — the profound enlightenment experience you will have when you finally get it. That experience will make you a better programmer for the rest of your days, even if you never actually use LISP itself a lot. (You can get some beginning experience with LISP fairly easily by writing and modifying editing modes for the Emacs text editor, or Script-Fu plugins for the GIMP.)

It's best, actually, to learn all five of Python, C/C++, Java, Perl, and LISP. Besides being the most important hacking languages, they represent very different approaches to programming, and each will educate you in valuable ways.

I can't give complete instructions on how to learn to program here — it's a complex skill. But I can tell you that books and courses won't do it (many, maybe most of the best hackers are self-taught). You can learn language features — bits of knowledge — from books, but the mind-set that makes that knowledge into living skill can be learned only by practice and apprenticeship. What will do it is (a) reading code and (b) writing code.

Peter Norvig, who is one of Google's top hackers and the co-author of the most widely used textbook on AI, has written an excellent essay called Teach Yourself Programming in Ten Years. His "recipe for programming success" is worth careful attention.

Learning to program is like learning to write good natural language. The best way to do it is to read some stuff written by masters of the form, write some things yourself, read a lot more, write a little more, read a lot more, write some more ... and repeat until your writing begins to develop the kind of strength and economy you see in your models.

Finding good code to read used to be hard, because there were few large programs available in source for fledgeling hackers to read and tinker with. This has changed dramatically; open-source software, programming tools, and operating systems (all built by hackers) are now widely available. Which brings me neatly to our next topic...

2. Get one of the open-source Unixes and learn to use and run it.
I'll assume you have a personal computer or can get access to one. (Take a moment to appreciate how much that means. The hacker culture originally evolved back when computers were so expensive that individuals could not own them.) The single most important step any newbie can take toward acquiring hacker skills is to get a copy of Linux or one of the BSD-Unixes or OpenSolaris, install it on a personal machine, and run it.

Yes, there are other operating systems in the world besides Unix. But they're distributed in binary — you can't read the code, and you can't modify it. Trying to learn to hack on a Microsoft Windows machine or under any other closed-source system is like trying to learn to dance while wearing a body cast.

Under Mac OS X it's possible, but only part of the system is open source — you're likely to hit a lot of walls, and you have to be careful not to develop the bad habit of depending on Apple's proprietary code. If you concentrate on the Unix under the hood you can learn some useful things.

Unix is the operating system of the Internet. While you can learn to use the Internet without knowing Unix, you can't be an Internet hacker without understanding Unix. For this reason, the hacker culture today is pretty strongly Unix-centered. (This wasn't always true, and some old-time hackers still aren't happy about it, but the symbiosis between Unix and the Internet has become strong enough that even Microsoft's muscle doesn't seem able to seriously dent it.)

So, bring up a Unix — I like Linux myself but there are other ways (and yes, you can run both Linux and Microsoft Windows on the same machine). Learn it. Run it. Tinker with it. Talk to the Internet with it. Read the code. Modify the code. You'll get better programming tools (including C, LISP, Python, and Perl) than any Microsoft operating system can dream of hosting, you'll have fun, and you'll soak up more knowledge than you realize you're learning until you look back on it as a master hacker.

For more about learning Unix, see The Loginataka. You might also want to have a look at The Art Of Unix Programming.

To get your hands on a Linux, see the Linux Online! site; you can download from there or (better idea) find a local Linux user group to help you with installation. From a new user's point of view, all Linux distributions are pretty much equivalent.

A good way to dip your toes in the water is to boot up what Linux fans call a live CD, a distribution that runs entirely off a CD without having to modify your hard disk. This will be slow, because CDs are slow, but it's a way to get a look at the possibilities without having to do anything drastic.

You can find BSD Unix help and resources at www.bsd.org.

I have written a primer on the basics of Unix and the Internet.

(Note: I don't really recommend installing either Linux or BSD as a solo project if you're a newbie. For Linux, find a local Linux user's group and ask for help.)

3. Learn how to use the World Wide Web and write HTML.
Most of the things the hacker culture has built do their work out of sight, helping run factories and offices and universities without any obvious impact on how non-hackers live. The Web is the one big exception, the huge shiny hacker toy that even politicians admit has changed the world. For this reason alone (and a lot of other good ones as well) you need to learn how to work the Web.

This doesn't just mean learning how to drive a browser (anyone can do that), but learning how to write HTML, the Web's markup language. If you don't know how to program, writing HTML will teach you some mental habits that will help you learn. So build a home page. Try to stick to XHTML, which is a cleaner language than classic HTML. (There are good beginner tutorials on the Web; here's one.)

But just having a home page isn't anywhere near good enough to make you a hacker. The Web is full of home pages. Most of them are pointless, zero-content sludge — very snazzy-looking sludge, mind you, but sludge all the same (for more on this see The HTML Hell Page).

To be worthwhile, your page must have content — it must be interesting and/or useful to other hackers. And that brings us to the next topic...

4. If you don't have functional English, learn it.
As an American and native English-speaker myself, I have previously been reluctant to suggest this, lest it be taken as a sort of cultural imperialism. But several native speakers of other languages have urged me to point out that English is the working language of the hacker culture and the Internet, and that you will need to know it to function in the hacker community.

Back around 1991 I learned that many hackers who have English as a second language use it in technical discussions even when they share a birth tongue; it was reported to me at the time that English has a richer technical vocabulary than any other language and is therefore simply a better tool for the job. For similar reasons, translations of technical books written in English are often unsatisfactory (when they get done at all).

Linus Torvalds, a Finn, comments his code in English (it apparently never occurred to him to do otherwise). His fluency in English has been an important factor in his ability to recruit a worldwide community of developers for Linux. It's an example worth following.

Being a native English-speaker does not guarantee that you have language skills good enough to function as a hacker. If your writing is semi-literate, ungrammatical, and riddled with misspellings, many hackers (including myself) will tend to ignore you. While sloppy writing does not invariably mean sloppy thinking, we've generally found the correlation to be strong — and we have no use for sloppy thinkers. If you can't yet write competently, learn to.

Like most cultures without a money economy, hackerdom runs on reputation. You're trying to solve interesting problems, but how interesting they are, and whether your solutions are really good, is something that only your technical peers or superiors are normally equipped to judge.

Accordingly, when you play the hacker game, you learn to keep score primarily by what other hackers think of your skill (this is why you aren't really a hacker until other hackers consistently call you one). This fact is obscured by the image of hacking as solitary work; also by a hacker-cultural taboo (gradually decaying since the late 1990s but still potent) against admitting that ego or external validation are involved in one's motivation at all.

Specifically, hackerdom is what anthropologists call a gift culture. You gain status and reputation in it not by dominating other people, nor by being beautiful, nor by having things other people want, but rather by giving things away. Specifically, by giving away your time, your creativity, and the results of your skill.

There are basically five kinds of things you can do to be respected by hackers:

1. Write open-source software
The first (the most central and most traditional) is to write programs that other hackers think are fun or useful, and give the program sources away to the whole hacker culture to use.

(We used to call these works “free software”, but this confused too many people who weren't sure exactly what “free” was supposed to mean. Most of us now prefer the term “open-source” software).

Hackerdom's most revered demigods are people who have written large, capable programs that met a widespread need and given them away, so that now everyone uses them.

But there's a bit of a fine historical point here. While hackers have always looked up to the open-source developers among them as our community's hardest core, before the mid-1990s most hackers most of the time worked on closed source. This was still true when I wrote the first version of this HOWTO in 1996; it took the mainstreaming of open-source software after 1997 to change things. Today, "the hacker community" and "open-source developers" are two descriptions for what is essentially the same culture and population — but it is worth remembering that this was not always so.

2. Help test and debug open-source software
They also serve who stand and debug open-source software. In this imperfect world, we will inevitably spend most of our software development time in the debugging phase. That's why any open-source author who's thinking will tell you that good beta-testers (who know how to describe symptoms clearly, localize problems well, can tolerate bugs in a quickie release, and are willing to apply a few simple diagnostic routines) are worth their weight in rubies. Even one of these can make the difference between a debugging phase that's a protracted, exhausting nightmare and one that's merely a salutary nuisance.

If you're a newbie, try to find a program under development that you're interested in and be a good beta-tester. There's a natural progression from helping test programs to helping debug them to helping modify them. You'll learn a lot this way, and generate good karma with people who will help you later on.

3. Publish useful information
Another good thing is to collect and filter useful and interesting information into web pages or documents like Frequently Asked Questions (FAQ) lists, and make those generally available.

Maintainers of major technical FAQs get almost as much respect as open-source authors.

4. Help keep the infrastructure working
The hacker culture (and the engineering development of the Internet, for that matter) is run by volunteers. There's a lot of necessary but unglamorous work that needs done to keep it going — administering mailing lists, moderating newsgroups, maintaining large software archive sites, developing RFCs and other technical standards.

People who do this sort of thing well get a lot of respect, because everybody knows these jobs are huge time sinks and not as much fun as playing with code. Doing them shows dedication.

5. Serve the hacker culture itself
Finally, you can serve and propagate the culture itself (by, for example, writing an accurate primer on how to become a hacker :-)). This is not something you'll be positioned to do until you've been around for while and become well-known for one of the first four things.

The hacker culture doesn't have leaders, exactly, but it does have culture heroes and tribal elders and historians and spokespeople. When you've been in the trenches long enough, you may grow into one of these. Beware: hackers distrust blatant ego in their tribal elders, so visibly reaching for this kind of fame is dangerous. Rather than striving for it, you have to sort of position yourself so it drops in your lap, and then be modest and gracious about your status.


The Hacker/Nerd Connection
Contrary to popular myth, you don't have to be a nerd to be a hacker. It does help, however, and many hackers are in fact nerds. Being something of a social outcast helps you stay concentrated on the really important things, like thinking and hacking.

For this reason, many hackers have adopted the label ‘geek’ as a badge of pride — it's a way of declaring their independence from normal social expectations (as well as a fondness for other things like science fiction and strategy games that often go with being a hacker). The term 'nerd' used to be used this way back in the 1990s, back when 'nerd' was a mild pejorative and 'geek' a rather harsher one; sometime after 2000 they switched places, at least in U.S. popular culture, and there is now even a significant geek-pride culture among people who aren't techies.

If you can manage to concentrate enough on hacking to be good at it and still have a life, that's fine. This is a lot easier today than it was when I was a newbie in the 1970s; mainstream culture is much friendlier to techno-nerds now. There are even growing numbers of people who realize that hackers are often high-quality lover and spouse material.

If you're attracted to hacking because you don't have a life, that's OK too — at least you won't have trouble concentrating. Maybe you'll get a life later on.


Points For Style
Again, to be a hacker, you have to enter the hacker mindset. There are some things you can do when you're not at a computer that seem to help. They're not substitutes for hacking (nothing is) but many hackers do them, and feel that they connect in some basic way with the essence of hacking.

Learn to write your native language well. Though it's a common stereotype that programmers can't write, a surprising number of hackers (including all the most accomplished ones I know of) are very able writers.

Read science fiction. Go to science fiction conventions (a good way to meet hackers and proto-hackers).

Train in a martial-arts form. The kind of mental discipline required for martial arts seems to be similar in important ways to what hackers do. The most popular forms among hackers are definitely Asian empty-hand arts such as Tae Kwon Do, various forms of Karate, Kung Fu, Aikido, or Ju Jitsu. Western fencing and Asian sword arts also have visible followings. In places where it's legal, pistol shooting has been rising in popularity since the late 1990s. The most hackerly martial arts are those which emphasize mental discipline, relaxed awareness, and control, rather than raw strength, athleticism, or physical toughness.

Study an actual meditation discipline. The perennial favorite among hackers is Zen (importantly, it is possible to benefit from Zen without acquiring a religion or discarding one you already have). Other styles may work as well, but be careful to choose one that doesn't require you to believe crazy things.

Develop an analytical ear for music. Learn to appreciate peculiar kinds of music. Learn to play some musical instrument well, or how to sing.

Develop your appreciation of puns and wordplay.

The more of these things you already do, the more likely it is that you are natural hacker material. Why these things in particular is not completely clear, but they're connected with a mix of left- and right-brain skills that seems to be important; hackers need to be able to both reason logically and step outside the apparent logic of a problem at a moment's notice.

Work as intensely as you play and play as intensely as you work. For true hackers, the boundaries between "play", "work", "science" and "art" all tend to disappear, or to merge into a high-level creative playfulness. Also, don't be content with a narrow range of skills. Though most hackers self-describe as programmers, they are very likely to be more than competent in several related skills — system administration, web design, and PC hardware troubleshooting are common ones. A hacker who's a system administrator, on the other hand, is likely to be quite skilled at script programming and web design. Hackers don't do things by halves; if they invest in a skill at all, they tend to get very good at it.

Finally, a few things not to do.

Don't use a silly, grandiose user ID or screen name.

Don't get in flame wars on Usenet (or anywhere else).

Don't call yourself a ‘cyberpunk’, and don't waste your time on anybody who does.

Don't post or email writing that's full of spelling errors and bad grammar.

The only reputation you'll make doing any of these things is as a twit. Hackers have long memories — it could take you years to live your early blunders down enough to be accepted.

The problem with screen names or handles deserves some amplification. Concealing your identity behind a handle is a juvenile and silly behavior characteristic of crackers, warez d00dz, and other lower life forms. Hackers don't do this; they're proud of what they do and want it associated with their real names. So if you have a handle, drop it. In the hacker culture it will only mark you as a loser.