three times shuttle

Chapter 2 Hacking into the National Library

"Please note that in another 5 minutes, the central server will open access rights for half an hour, and you can freely choose review materials and exam questions for each subject over the years, and download them to the local terminal for study.

You have a total of four hours. At 01:30 noon, the content in the personal directory will be cleared. Please leave as soon as possible at that time so that the staff can clean up and welcome the next batch of candidates. "The soft voice of the female announcer sounded.

Time passed, "After 30 seconds, everyone can log in to their account, create a personal directory, and click the central server icon at the top of the screen. Good luck."

Ning Chengfeng slowly opened his eyes, and the fresh air system just sent a gust of fresh air from the right side, which was also mixed with a mysterious mixed floral fragrance, which was very feminine.

"It smells so good. What kind of perfume is this girl wearing? When Lingxi has a body, try to get her a bottle. Alas, I probably can't afford it." Out of instinct, he turned his head and glanced at the beauty with short black hair.

"At 09:30, candidates start studying." The announcer reminded.

"Crackling", the sound of typing on the keyboard came one after another. He hurriedly entered the terminal number in the upper right corner of the desktop display into the user field, and then filled in the secret key on the identity chip into the password box.

"Successful login", he abbreviated himself and Lingxi to create a local directory.Full of expectations, the young man clicked on the yellow "Central Server" icon above.

The door of knowledge opens, and the windows of eight subjects, including mathematics, logical reasoning, literature, mechanics, computer, physics, chemistry and geography, pop up at the same time.

He clicked on "Mathematics" first, and was immediately dumbfounded.The question bank is endless, there are exam questions, there are also annual review points, there are federal exams, and there are exams from various continents, which are classified into various categories.

Randomly opened an examination paper, there were a lot of questions in it, he didn't read it carefully, and read last year's review questions instead, the content was even more frightening.

As for the catalogs of each continent, he tried to browse through two, and couldn't help but sigh: "I definitely can't finish reading, so I can only focus on the federal exam questions first."

After making a decision, he downloaded the relevant materials of the last ten years to the local area, and then did the same for the other seven.

Ning Chengfeng showed a satisfied smile and looked at the clock on the wall. Only five minutes had passed. When he looked away, he scanned the screen of the beauty next to him, and found that the icon of the central server appeared again.

"This girl's movements are really fast, she has already finished downloading, and returned to her personal page to study by herself, I have to speed up."

He imitated the example, read the test questions quickly, and checked the answers and analysis when he couldn't meet them, and 10 minutes passed quietly.

Computer subjects are his forte. When he was about to finish reading, he finally encountered a difficult problem. While thinking hard, he inhaled slightly through his nose, enjoying the charming fragrance of flowers again, and couldn't help being distracted:
"The test questions for the final exam are the same, but every time the results are announced, the robots are far ahead. Although their memory and computing power are stronger, they are not so outrageous? Will their review question bank be different from ours, and closer to us? Real test questions?"

He shook his head and laughed at himself, "The time is so tight, and I still deserted. I promised Lingxi to read at the speed I trained at home."

He cheered up, finished the difficult problem quickly, and switched to astronomy, but he heard a crisp sound of "pop", the beauty tapped the keyboard happily, and then sighed in satisfaction.

"I'm so happy, have I made significant progress? But I still can't do anything, it's unreasonable and a bit weird." Ning Chengfeng was quite abnormal, and was disturbed by the woman next to him many times, so he had doubts.

The young man forcibly focused on the exam question in front of him. He was gentle in nature, but somehow he had a crazy idea:

"If you use her privileges to access the mainframe, you can download the robot's data! That's really fair competition. Oh, no, if you are caught, you will go to jail."

"Everyone has only one chance to apply for the civil service examination. My success rate is less than 40.00%, and most of them will not be admitted. Why not take a chance?" Once weeds appear in my heart, they will grow uncontrollably.

"This may be an opportunity given to me by God. There are still 4 or [-] minutes left before the host will be disconnected. With my hacker level, not only will I be able to make it in time, but I will not be discovered." Gambling made him lose his mind.

He hesitated for six seconds before making up his mind: "How often do you gamble in life? Take a gamble today."

Every once in a while, the electronic patrol bug in the air and the camera on the wall will detect his location. If the operation window is opened very small, the view can be blocked with the body.

"Black girls focus on data access, and spoofing or phishing based on DNS, email or the Web will not work.

If you attack the intranet gateway and try to read the underlying address of the next-door terminal from the routing table, it is likely to be detected by the firewall. The safest way is to impersonate her computer. "

He tapped the keyboard, opened a new window at the bottom of the screen, entered one command after another, and carried out simple attacks.

Since they are on the same intranet, he easily isolates the beauty's terminal so that it cannot receive any valid network data, in case it is exposed on the spot.

The second step is the most troublesome. He needs to guess the initial serial number ISN of the other party's data packet, which is a string of 32-bit binary characters.

He used his own terminal to connect to a port of the host, sent a request to it, and got a response.The timer accurately records the round-trip time RTT of the data, and after several consecutive times, he calculates the average value of the RTT.

"For this level of protection, most hosts use the traditional serial number mechanism." It didn't take long to find out the pattern: "ISN increases by 128000 per second, and 64000 per connection."

He looked happy, and listed a simple formula: "128000*RTT/2", if the host has just established a connection at this time, add 64000, it will be the next serial number, "Sniffing successful!"

The third step is to disguise the address of the local machine as the one next door, and use this ISN to send a connection request to the host.

The other party responded by sending back a data packet with a serial number and confirmation flag to the paralyzed terminal, which the beauty naturally could not receive.

When the last step comes, he needs to impersonate himself, pretend that he has received it, and according to the formula, refresh the ISN, and send a packet back to the host, prompting it to accept the attached confirmation sign while recognizing the initial serial number, "connection established!"

Ning Chengfeng secretly rejoiced that due to his highly clear mind and quick hands and feet, a series of dazzling operations just now hacked into the insufficiently protected host without anyone noticing. It seems that no candidate has dared to attack like this before.

The clock on the wall showed that there were more than eight minutes before the host would disconnect.

The icon of the central server appeared on his screen again, and he clicked to enter the robot candidate's page. In addition to the review questions of each subject, there was an additional directory: "Other materials".

He suppressed his excitement, first looked at the past exam questions, and found that it was no different from the ones he had seen.Looking at the review materials again, they are few but excellent, and I can't help cursing secretly:

"No wonder those iron bumps can do so well in the exam. They have a special exam outline."

Hastily downloaded all the content to this machine, with 49 minutes and [-] seconds left, he curiously pointed to the fuchsia directory, "Other information", he muttered to himself.

Ning Chengfeng enters a brand new world, the content inside is all-encompassing, dazzling and fascinating.

Driven by his innate obsession, he entered the word "xiuxian" in the search box, and a blue directory flashed on the screen, and after clicking, it displayed: "No access".

He was disappointed for a while, but he didn't give up. He used "cultivation", "gongfa", "secret book" and "martial skills" successively to try, all with the same result.

In desperation, I entered "meditate", and this time, there were actually many answers.Most of them are robots, or half-humans that are used to transform thoroughly. There is only one article "Fate Shuttle", which is the method of breathing for the human race, with pictures and text.

He tried to download it, but the system reminded him of "insufficient permissions", so he had to read it. Fortunately, he has a superb memory, so he memorized it rotely.

With only the last 31 seconds left, he remembered the legend in the third-class citizen, and wrote in the search box: "How are human beings ruled?"

A large number of documents were listed, including text, pictures, and videos. Time was limited, so he directly selected the text content in the first line.

In today's world, that history is taboo and top secret for second- and third-class citizens.

Because of his excitement and curiosity, he was not as alert as before to the consequences of illegal theft of information.

A dusty secret history is presented in front of Ning Chengfeng.

(End of this chapter)