First, setup your bomb directory. How does loop address alignment affect the speed on Intel x86_64? offer the lab. Unexpected uint64 behaviour 0xFFFF'FFFF'FFFF'FFFF - 1 = 0? Each binary bomb is a program, running a sequence of phases. Okay, we know it works. The second number is simply linked to the first number: 0 must be followed by 704, 1 by 848, 2 by 736, 3 by 346, 4 by 607, 5 by 147, 6 by 832, and 7 by 536. The purpose of this project is to become more familiar with machine level programming. The ./bomblab directory contains the following files: Makefile - For starting/stopping the lab and cleaning files, bomblab.pl* - Main daemon that nannies the other servers & daemons, Bomblab.pm - Bomblab configuration file, bomblab-reportd.pl* - Report daemon that continuously updates scoreboard, bomblab-requestd.pl* - Request server that serves bombs to students, bomblab-resultd.pl* - Result server that gets autoresult strings from bombs, bomblab-scoreboard.html - Real-time Web scoreboard, bomblab-update.pl* - Helper to bomblab-reportd.pl that updates scoreboard, bombs/ - Contains the bombs sent to each student, log-status.txt - Status log with msgs from various servers and daemons, log.txt - Scoreboard log of autoresults received from bombs, makebomb.pl* - Helper script that builds a bomb, scores.txt - Summarizes current scoreboard scores for each student, src/ - The bomb source files, writeup/ - Sample Latex Bomb Lab writeup, LabID: Each instance (offering) of the lab is identified by a unique, name, e.g., "f12" or "s13", that the instructor chooses. frequency is a configuration variable in Bomblab.pm. The makebomb.pl script also generates the bomb's solution. Become familiar with Linux VM and Linux command-line, Use and navigate through gdb debugger to examine memory and registers, view assembly code, and set breakpoints within the gdb debugger, Read and understand low level assembly code. phase_6 We can then set up a breakpoint upon entering phase_1 using b phase_1 and for the function explode_bomb to avoid losing points. Now you can see there are a few loops. your answer turns out to be 21 115, The solution is : 5 115. If one of these processes dies for some reason, the main daemon, detects this and automatically restarts it. You get to know that the input sequence must be an arbitary combination of number 1,2,3,4,5,6. When, the student untars this file, it creates a directory (./bomb) with, bomb* Notifying custom bomb executable, bomb.c Source code for the main bomb routine, ID Identifies the student associated with this bomb, README Lists bomb number, student, and email address, The request server also creates a directory (bomblab/bombs/bomb), bomb.c Source code for main routine, bomb-quiet* A quiet version of bomb used for autograding, ID Identifies the user name assigned to this bomb, phases.c C source code for the bomb phases, README Lists bombID, user name, and email address, Result Server: Each time a student defuses a phase or explodes their, bomb, the bomb sends an HTTP message (called an autoresult string) to, the result server, which then appends the message to the scoreboard, log. As its currently written, your answer is unclear. When in doubt "make stop; make start" will get everything in a stable state. The request server builds the, bomb, archives it in a tar file, and then uploads the resulting tar, file back to the browser, where it can be saved on disk and, untarred. "make stop" kills all of the running, servers. Bomb Lab: Phase 5. Cannot retrieve contributors at this time. You have 6 phases with which to blow yourself up. At the onset of the program you get the string 'Welcome to my fiendish little bomb. If you're looking for a specific phase: Here is Phase 1. Specifically: That's number 2. Link to Bomb Lab Instructions (pdf) in GitHub Repository. Do this only during debugging, or the very first time, Students request bombs by pointing their browsers at, Students view the scoreboard by pointing their browsers at, http://$SERVER_NAME:$REQUESTD_PORT/scoreboard, (1) Resetting the Bomb Lab. our input has to be a string of 6 characters, the function accepts this 6 character string and loops over each character in it, the result of the loop is compared to a fixed string, and if theyre equal, the bomb doesnt explode. A tag already exists with the provided branch name. Given this info, it looks as though the loop is implementing a cypher. Dump of assembler code for function phase_5: 0x0000000000401002 <+0>: sub $0x18,%rsp ; rsp = rsp - 24, 0x0000000000401006 <+4>: lea 0x8(%rsp),%rcx ; rcx = *(rsp + 8) (function argument), 0x000000000040100b <+9>: lea 0xc(%rsp),%rdx ; rdx = *(rsp + 12) (function argument), 0x0000000000401010 <+14>: mov $0x401ebe,%esi ; esi = "%d %d", 0x0000000000401015 <+19>: mov $0x0,%eax ; eax = 0, 0x000000000040101a <+24>: callq 0x400ab0 <__isoc99_sscanf@plt>, 0x000000000040101f <+29>: cmp $0x1,%eax ; if (eax > 1) goto 0x401029, 0x0000000000401022 <+32>: jg 0x401029 , 0x0000000000401024 <+34>: callq 0x40163d ; if (eax <= 1) explode_bomb(), 0x0000000000401029 <+39>: mov 0xc(%rsp),%eax ; eax = *(rsp + 12) ::function parameter, 0x000000000040102d <+43>: and $0xf,%eax ; eax = eax & 0xf (last 2 bits), 0x0000000000401030 <+46>: mov %eax,0xc(%rsp) ; *(rsp + 12) = eax, 0x0000000000401034 <+50>: cmp $0xf,%eax ; if (eax == 0xf) explode_bomb(), 0x0000000000401037 <+53>: je 0x401065 , 0x0000000000401039 <+55>: mov $0x0,%ecx ; ecx = 0, 0x000000000040103e <+60>: mov $0x0,%edx ; edx = 0, 0x0000000000401043 <+65>: add $0x1,%edx ; edx = edx + 0x1, 0x0000000000401046 <+68>: cltq ; sign extend eax to quadword (rax), 0x0000000000401048 <+70>: mov 0x401ba0(,%rax,4),%eax ; eax = *(rax * 4 + 0x401ba0), 0x000000000040104f <+77>: add %eax,%ecx ; ecx = ecx + eax, 0x0000000000401051 <+79>: cmp $0xf,%eax ; if (eax != 0xf) goto 0x401043 (inc edx), 0x0000000000401054 <+82>: jne 0x401043 , 0x0000000000401056 <+84>: mov %eax,0xc(%rsp) ; *(rsp + 12) = eax, 0x000000000040105a <+88>: cmp $0xc,%edx ; if (edx != 12) explode_bomb(), 0x000000000040105d <+91>: jne 0x401065 , 0x000000000040105f <+93>: cmp 0x8(%rsp),%ecx ; if (ecx == *(rsp + 8)) goto 0x40106a, 0x0000000000401063 <+97>: je 0x40106a , 0x0000000000401065 <+99>: callq 0x40163d ; explode_bomb(), 0x000000000040106a <+104>: add $0x18,%rsp ; rsp = rsp + 24, 0x000000000040106e <+108>: retq ; return, --------------------------------------------------------------------------------. So, what do we know about phase 5 so far? CS3330: Lab 1 (Bomb Lab) 10 January 2015. Find centralized, trusted content and collaborate around the technologies you use most. Also note that the binary follow the AT&T standard so instruction operations are reversed (e.g. gdbCfg phase 5. The goal for the students is to defuse as many phases as possible. invalid_phase Cannot retrieve contributors at this time. I will likely take another shot at figureing out exactly how to come up with the solution by following the implemented logic but I eventually brute forced it, which took a whole 30 seconds to figure out. d = 12 If you solve the phase this way, youll actually notice that there is more than one correct solution. Bomb Lab: Phase 5. On line <phase_4+16>, the <phase_4> function is pushing a fixed value stored at memory address 0x8049808 onto the stack right before a call to scanf is made. We have created a stand-alone user-level autograding service that, handles all aspects of the Bomb Lab for you: Students download their, bombs from a server. You've defused the bomb! I dont want to go through either solution all the way here, since the first one is a no-brainer and the second one is a little complicated. Ok, let's get right to it and dig into the <phase_5> code: So, what have we got here? I then did the same for the possible second pointer arguement which would be in %rsi with x/s $rsi and get 'When I get angry, Mr. Bigglesworth gets upset.'. Here is Phase 6. 1) We have to find that number 'q' which will cause 12 (twelve) iterations. Many Git commands accept both tag and branch names, so creating this branch may cause unexpected behavior. If nothing happens, download Xcode and try again. What does the power set mean in the construction of Von Neumann universe? So you think you can stop the bomb with ctrl-c, do you?' First, to figure out that the program wants a string as an input. Analysis of Binary Bomb Lab GitHub A tag already exists with the provided branch name. Remember this structure from Phase 2? Here is Phase 2. We can get the full assembly code using an object dump: objdump -d path/to/binary > temp.txt. I also found strings that look like they could be related to attribution: I inputed the word 'blah' and continued to run the program. Defusing CMU's Bomb Lab using GDB - Andrew Wei - GitHub Pages fun7 ??? What are the advantages of running a power tool on 240 V vs 120 V? skip Attack Lab Phase 1: Buffer Overflow (CS:APP) - YouTube which to blow yourself up. It's a great. A tag already exists with the provided branch name. I see the output 'Phase 1 defused. node5 Bomb lab phase 6 github - ayafpo.saligia-kunst.de We've made it very easy to run the service, but, some instructors may be uncomfortable with this requirement and will. Lets use blah again as out input for phase_2. Based on the first user inputed number, you enter into that indexed element of the array, which then gives you the index of the next element in the array, etc. There was a problem preparing your codespace, please try again. You've defused the bomb!'. Try this . You signed in with another tab or window. DrEvil After looking at the static Main() code, I've got a reasonable understanding of the gross control flow through this program now lets do a more dynamic analysis with GDB. If there is a, problem (say because you forgot to update the list of machines the, bombs are allowed to run in src/config.h) you can fix the, configuration, reset the lab, and then request and run more test, CAUTION: If you reset the lab after it's live, you'll lose all your, records of the students bombs and their solutions. I hope it's helpful. "/> dearborn police incident reports. Bomb explosions. In this exercise, we have a binary whose source we do not have. And, as you can see at structure, the loop iterates 6 times. These numbers act as indices within a six element array in memory, each element of which contains a number. Have a nice day!' Cannot retrieve contributors at this time. First, interesting sections/function names: Let me know if you have any questions in the comments. If you type the correct string, then. More than 2 is fine but the code is only dependent on the first two numbers. From this, we can guess that to pass phase_1, we need to enter the correct string. You've defused the secret stage! The code must be at least six numbers long or else the bomb detonates. Here is the assembly code: The list of numbers I've inputed is this: So far from my understanding, two conditions need to be met: compare %ecx is 115 line 103 ', It is not clear what may be the output string for solving stage 4 or 5. Here is Phase 6. On the bright side, at least now we know that our string should come out of the loop as giants. Keep going! Actually in this part, the answer isn't unique. From this mapping table, we can figure out the un-cyphered version of giants. Making statements based on opinion; back them up with references or personal experience. Are you sure you want to create this branch? For each bomb, it tallies the number, of explosions, the last defused phase, validates each last defused, phase using a quiet copy of the bomb, and computes a score for each, student in a tab delimited text file called "scores.txt." Bomb Lab - Hang's Blog Ultimately to pass this test all you need to do is input any string of 46 characters in length that does not start with a zero. Could this mean alternative endings? This part is really long. Defusing the binary bomb - Myst!qu3 S@lt Link to Bomb Lab Instructions (pdf) in GitHub Repository explode_bomb After solving stage 1 you likely get the string 'Phase 1 defused. PHASE 3. Here are a few useful commands that are worth highlighting: This command divides the screen into two parts: the command console and a graphical view of the assembly code as you step through it. GitHub Microsoft is acquiring GitHub!Read our blog and Satya Nadella's post to learn more. Identify the generic Linux machine ($SERVER_NAME) where you will, create the Bomb Lab directory (./bomblab) and, if you are offering the, online version, run the autograding service. sc2225/Bomb-Lab - Github The previous output from the strings program was outputted to stout in order that the strings are found in the binary. The request server parses the form, builds and, tars up a notifying custom bomb with bombID=n, and delivers the tar, file to the browser. Keep going! This looks familiar! Content Discovery initiative April 13 update: Related questions using a Review our technical responses for the 2023 Developer Survey. A clear, concise, correct answer will earn full credit. Since there exists a bunch of different versions of this problem, I' ve already uploaded my version. How about the next one? The key part is the latter one. The values came out it the following format: 0x000003b8 So if I order the nodes in ascending order, it should be 6 4 1 2 5 3, but this still wasn't the correct input. From phase_4, we call the four arguments of func4 to be a, b(known, 0), c(known, 14), d(known, 0). While layout asm is helpful, also helpful to view the complete disassembled binary. So, I mapped out the array from element 0 to 15 and then worked backwards through it to find the element I needed to start with. servers running. Give 0 to ebp-8, which is used as loop condition. Type "./makebomb.pl -h" to see its arguments. The main daemon is the. bomblab-Angr/Phase 5 x86_64.ipynb. I don't want to run the program/"pull the pin" on the bomb by running it, so this tells me that there are likely 6 stages to the bomb. main correctly, else you and your students won't be able to run your bombs. string_length() - This function first checks to see that the passed character pointer in %rdi is not null terminated. It is passed the inputed user phrase and the pass-phrase and then checks that the two strings are the same length. As an experienced engineer, I believe you can figure out that there are two arguments, each of which should be integers. This part is a little bit trickier. sign in Then you get the answer to be the pair(7, 0). Have a nice day! phase_6 Have a nice day! This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository. The second input had to be a 11, because the the phase_4 code did a simple compare, nothing special. BombID: Each bomb in a given instance of the lab has a unique, non-negative integer called the "bombID. I dereference the string pointed to by %rdi using x/s $rdi and see that the string pointed to is 'blah'. Each line is annotated. You won't be able, to validate the students handins. I am currently stuck on bomb lab phase 5. I know b7 < eb < f6 < 150 < 21f < 304, so the order of nodes should be 3 0 5 4 1 2 (or 2 5 0 1 4 3 - in ascending order) and I should add +1 to all numbers. Phase 1 defused. phase_5() - This function requires you to go backwards through an array of numbers to crack the code. First, the numbers must be positive. initialize_bomb Work fast with our official CLI. It also might be easier to visualize the operations by using an online disambler like https://onlinedisassembler.com/ to see a full graph. The first number we can try to be 6 and the second must be 682. Each element in the array has an empty element directly adjacent to it. . The autograding service consists of four user-level programs that run, - Request Server (bomblab-requestd.pl). You signed in with another tab or window. phase_5 Did the drapes in old theatres actually say "ASBESTOS" on them? Using layout asm, we can see the assembly code as we step through the program. node4 Next, the, student fills in this form with their user name and email address, and, then submits the form.
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