Introduction to CTF

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As the area where information security is becoming more and more important, and the CTF (Capture the flag) as a form of competition for the selection of talents and competing skill levels in the field of information security, it has also been a growing concern, and as a novice to the new CTF, How do you soar through the big races and get your place on the first page of the ranking list? As a veteran in the CTF field for more than two years, to talk about my own experience in the introductory time, as well as touch the stone after the river some of the feelings of dogs.

About CTF

For the sake of pure novice to understand what is a CTF, I think about it or write a few more words here.

As a kind of game form of information security, CTF has three kinds of forms, problem-solving mode, attack-defense mode and blind mode at present.

Problem-solving mode, is the question of some information security in the actual combat may encounter problems to abstract into a topic, such as a loophole in the site let you invade, a program with decryption algorithm let you reverse to write a register machine, a loophole program let you analyze to write the exploit program, a cipher to decrypt you, A picture lets you find a seed from inside and so on. And when you're done with what these people expect you to do, you get a string of strange strings, called flag, that you can get to the score on this topic.

and offense and defense mode, generally appear under the online CTF, each team to maintain their own servers, attacks on other people's servers, each team's server began to have the same settings, such as several vulnerable binary programs, vulnerable Web applications, and so on, and then we need to find these vulnerabilities, Fix vulnerabilities on your own server and exploit these vulnerabilities to attack someone else's server.

Blind mode, you can see the beginning of this year, Japan's Seccon final and the annual ICTF and so on, is to put some plot ah set AH and CTF together to engage in some interesting game.

Beginners generally contact the basic is the online CTF competition, most of them are problem-solving mode.

I took my clothes two years ago.

My life to participate in the first CTF (or similar to the CTF game, because it was not called CTF), is the Hangzhou computer Science and Engineering, held at the end of 2012 the information security contest, at that time I was just a standard PC professional code dog, in addition to write some code, understand some of the basic use of Linux, Some tips and some basic sqli and XSS skills (at that time it seems to be a little OD, but now forget the light), I was from then into the CTF door (into the CTF pit), so everyone started to participate in the CTF, understand some basic security skills can go to the battlefield. Side to participate in learning, do not understand asked the dog, can not find the answer to the question in English again to describe the problem, then asked Google. (Small part: This is the first time of the overbearing President)

The CTF contains safety knowledge.

The CTF contains almost all the information security knowledge, so the CTF is great for getting started as an information security enthusiast.

Binary program Reverse analysis, binary Program Vulnerability Mining and utilization, operating system and security, mobile security (Android reverse and vulnerability analysis, iOS reverse and Vulnerability Analysis), Network protocol analysis, Web attacks, Web log audit and analysis, steganography, cryptography applications, Router exploits, ACM programming, Forensic analysis of various environments, etc. (may be omitted)

I know what you say, but how do I take off?

The first is a solid computer foundation that cannot be fool on basic concepts, such as:

XX: "I am doing a question, why I have made a command to do want to rebound shell results can not receive Ah, other orders I will be able to carry out." ”

Me: "Which server did you play?" ”

XX: "My virtual machine ah, IP is 192.168.1.233"

Me: "..."

If you don't understand the joke above, you need to add some basic knowledge of the Internet.

Next is the knowledge of various aspects of the deep understanding and application, security is a very applied discipline, a lot of security problems are not in the theory is not sound, but in the implementation of the time out of such a problem. Do not understand the problem, can not read the other people write the answer or thought to feel that they will also, be sure to do it yourself.

The tips of a club

First, the solution of the game must not be on a topic on the card too long, at any time to record the ideas, not to go to do something else, and then come back to do.

Second, in the face of domestic competition, the brain hole must be large, because many of the domestic people also control the difficulty and the difference between the brain hole large, must be divergent thinking, like the following this add effect.

Third, a long time competition must buy snacks, generally do rise when you are not in the mood to eat, no snacks you are hungry, and then FB will be taken by others, and then your expression will be so.

Four, usually see good article skills, or their own tread on the pit, must be all in a small books on the convenience of access, or it is likely to have pits you will fall the second time.

Five, the terminal must be beautified, otherwise the efficiency of the problem will be very low.

Six, many web problems actually want to understand after all can be in the local environment debugging or fuzz, do not do.

Seven, must be a lot of advice to Google, must be a lot of advice to Google, must be a lot of advice to Google, must be a lot of advice to Google, must be a lot of advice to Google, must be a lot of advice to Google, must be a lot of advice to Google. (It's so important to say it 7 times)

(Make sure you learn to turn X for safety)

Next we recommend some resources (if you do not want to play CTF, but want to try to enter the field of information security, the following many resources are also very useful

Web Security

https://pentesterlab.com/

A very nice website, put some of the loopholes into an ISO, oneself in the local assumptions, and then directly from the web to hack into, until the permission, too cool.

http://www.hackthissite.org/

That year did a lot of their problems, understand some strange ideas, technology to upgrade to not very large.

http://www.wechall.net/

Brush a little before, can see a lot of topics, because the station is relatively long, so many problems if you can not do it on the Internet to find some of the problems.

http://bobao.360.cn/

(Make a soft ad.)

Binary security

http://bbs.pediy.com/

A Holy Land, I reverse the Enlightenment of the land, learned some basic things, but as a web dog, and then basically abandoned.

https://exploit-exercises.com/

Very cool, a series of questions packaged into an ISO, downloaded down to the local actual operation.

Cryptographic Science

http://overthewire.org/wargames/

Some of the wargame are about cryptography and have done some.

The principle and practice of cryptography

All I know about cryptography is that I have learned this book well (following the cryptography course of our School of mathematics).

Implicit writing technique

http://appleu0.sinaapp.com/?p=501

AppleU0 wrote a very good summary.

Forensic analysis

Some of the clever use of Linux basic commands, some forensic tools use, 16-based analysis, more experience and accumulated, and temporarily did not think of anything better than the resources. (The police uncle knows this better.)

Wang Po sells melons

http://gou.gg/

My blog, long time no update, lazy dog me, New Year hope to write more things up.

Http://weibo.com/d34dc47