Library: Fill & Download for Free

Stole library books sitting in computer labs. This is how I did that.Step 1: Get a user account with full controlI simply used a boot able pen drive having LINUX (KALI) on it. So, no need to look for passwords of admin account. Step 1 complete.Step 2: Get IP address of library serverWe have special computers in our library to check for the books that have been issued on our roll number. So, I started cmd on that computer and used "netstat" command and queried for books issued on my roll number. I got the IP address of library server on our network. I also noted down other things about this computer by using "ipconfig /all" command. I wanted things like subnet mask, default gateway and DNS servers.Step 3: Scan the library serverI used zenmap to scan the library server. I got list of open ports.Step 4: Try to break into library serverI used autopwn feature of metasploit to try to exploit into library server. But, it was patched and up to date. So, I started feeling a bit depressed.Step 5: Lots of cold drink and deep thinkingThis is most important step. This step took about 5 days to complete. I kept thinking about how the library management software is working. I noted these actions.Librarian scans the bar code on book and bar code on my I-card and selects some option and the book is issued on my roll number.To return the book, he would just scan the bar code on the book and it would be returned.Looking at these actions I concluded that computer did not require my roll number to return the book. Now this fact will alone will help to hack the system.Step 6: Sniff the networkI used wireshark to capture all data packets that were going to library server. From my scanning part, I knew that library server was running MySQL and a HTTP server. So, the library management system must be somehow using these services. But, I had no idea how. I captured a load of TCP packets.Step 7: Trying to understand, what the s**t was in those packetsI had never done packet analysis before. After a few minutes of Google, I found that it was just a few clicks task in wireshark and I was able to see the data in packets.For every book issued a packet with roll number and some unique ID was being sent. To return the same book to library, just a packet with that same unique ID was being sent. I guessed that unique ID is coming from bar code of the book.Step 8: Trying to understand the bar codeI started with Google. Read some articles about how bar code works. Downloaded an android app on phone to decode the bar code. None worked.Later, I realized, that when I used to check the books issued on my roll number from the computers in library, then that list also had a column saying book ID. So, it was simple.Step 9: Get book ID of books I hadI went to library and used the computer to see the books issued on my roll number. I noted down all the book IDs.Step 10: Asking a teacher for help (Indirectly)The book ID in data packet was in hex. The book ID I noted down was text and some numbers. I had no idea of how to convert that. After struggling with it for hours, I asked a teacher to help me convert it. It turned out very simple. Convert text and numbers in ASCII and convert that number in hex, each byte separately.Step 11: Trying to return a book with a fake packetI saved one of the return packets from wireshark. I opened it in hex-editor to edit it and replaced the hex representing the book ID with my book ID. I used LINUX file2wire tool to send that data packet to server.Step 12: Keeping fingers crossedTo my surprise, the book actually got returned and was now not showing up in my list of issued books.I used this to steal 87 books in total. I made a collection of all the books I liked.Being caughtThe librarian realized the large number of books missing during the counting done at end of each year. They called some guy from company which had made that library management system. Turned out, that software kept logs of everything. The guy figured out that all books that were missing were last issued in my roll number.The college officials called my home without notifying me and they got to know that I had two bookshelves full of computer science books.The college administration and guys from that company called me. I was too terrified. I thought that they would throw me out of college or something like that. But, to my surprise, the company official said that they would pay for all those books if I tell them how I did that. I spitted out every detail with all proof I could present. Nothing happened. College gave me a warning and company paid for all the books.At end of next semester, the college library manager called me. College was donating old books. So, the guy told me to take any number of books I wanted from the books that were going to be donated. I took 38 books more.All is well now. I have nice collection of computer science books at my home. :)

He raped a sales clerk. | Library of Congress Print and Picture Collection/Wikimedia CommonsThis is a tough choice. Several had dark pasts. But my vote goes to Grover Cleveland. He raped a sales clerk and then later had her committed to hide the fact.“Before Grover Cleveland married his wife in 1886 — during his first presidential term — he did a horrific thing. According to Charles Lachman, who spent three years digging into Cleveland’s past for his book, A Secret Life, Cleveland and his aides covered up a major sex scandal to save Cleveland’s presidential campaign. And clearly, it worked.”Maria Halpin, a 38-year-old sales clerk, alleges that on December 15, 1873 after the two had had dinner together that the 37 year old Cleveland raped her. Nine months later, she had a son — Cleveland’s illegitimate child. As the sad story goes, Cleveland had the child removed from his mother and placed in an orphanage. And then, he had Halpin placed in an insane asylum (although she was soon released by the facility’s director).You'll Never Believe the Dark Secrets America's Presidents Tried to Hide

Coding for time zones is hard because it’s a huge mess of edge cases, and each and every one of them is waiting to get you…Days are 24 hours long, right? WRONG: one day a year it’ll be 23 hours long and one day a year the day will be 25 hours long (on days where you “spring ahead” or “fall back” due to daylight savings time).There are 24 time zones because we have 24 hours in a day right? WRONG: There are currently 38 (source: How Many Time Zones Are There?)All time zones are offset on one hour, at least, right? WRONG: India is 5 hours 30 minutes from UTC. (There’s a couple others, but I know India’s well)But time zones approximately line up with geographic boundaries, right? WRONG: Arizona doesn’t have daylight savings time (so will appear one hour offset from where you would expect it in the map. Additional fun edge condition here: apparently Navajo (but not Hopi) reservations in Arizona _do_ have daylight savings time?! (source: No DST in Most of Arizona )I thought I recently heard of a proposed law that would make it a state decision if the state would be on daylight savings time or not. Imagine New York being in a different time zone than Florida, or PA and Georgia being an hour off. Sure, if you’re in the state it’s the same, but interstate commerce or family or friends is super duper a thing.But everyone switches daylight savings time at the same time, right? WRONG. Traditionally? Nope, the US moved it two weeks ahead during the Bush or Obama administration (or something like that)There IS a big database of time zones and information related to time zones, called the TZ database. Pretty much every major OS, language, or time zone related library uses this library. (“But certainly it must be a UN thing, this database?” Nope, currently maintained by the organization that maintains DNS worldwide. (Yes, really). Previous to that it was maintained by one-two guys, David Olsen and Paul Eggert. If you hear an ol’ timer talking about the “Olsen database” they’re talking about TZ). (source: Time Zone Database )A day is 60 * 60 * 24 seconds long, normally, right? Except two days a year, right? WRONG: leap seconds are a thing.But computer clocks are always right? WRONG: Computer clocks drift.It’s the same time everywhere. WRONG: Relativity is a thing (hi people writing software for NASA, or people who need sub-nanosecond precision no matter if you’re in Death Valley or on the top of Mt. Everest). For example, GPS has to include some calculations to compensate for relativity (38? 50? nanoseconds of it). (source: Why does GPS depend on relativity?)Are you beat down yet just reading this answer? That is the feeling you get from doing too much time zone related programming, my friend. Oh my goodness.So… how do you deal with this mess?Use your OS’s time zone libraries or some standard library for whatever language, and keep them up to date. For example, the night before I wrote this answer, jodatime, a popular datetime library for Java, just had a release to fix an incorrect time zone for Namibia (and maybe to deal with a timezone issue in Morocco?)Try to not assume the day is 60 * 60 * 24 seconds longThink about what will happen if you schedule that cron job to happen at 2:00 (one day it will not happen at all! one day it will happen twice!)Store dates as UTC in your database and translate them as close to the user as you can (maybe even have a “time zone preference” in your app if you have to!)Sometimes you’ll be fine. Are people often using your app in 2:00AM? You may be able to live with bugs like #2.Thankfully you’ll never run into some of these problems (relativity), and some you can deal with (make sure your computers and servers are hooked up to NTP).Sometimes your users will just smile (or file bugs against your app that you can’t do anything about). Like a recent Naomi Freeman (an awarded and prominent Woman In Tech) tweet which I’ve linked to below:I only knew the clocks changed because my Animal Crossing suddenly only had 4 minutes to catch magic fish when the day change should've been 1h4min away 🙃— Naomi Freeman (@Naomi_Freeman) October 28, 2018Good luck, and budget extra time for time/date tasks (I know I always do!)