CSC231 Lab 2 2015

--D. Thiebaut (talk) 07:15, 21 September 2015 (EDT)

---

Reverse Engineering

Recreate the original assembly program whose hexdump is shown below. You should call your program lab2.asm. In the process, answer the following questions:

• what is the name of the original assembly program?
• how many string variables does it contain?
• what are the names of the strings?
• what are the names of the constants?
• what is the original program's output?

00000000  7f 45 4c 46 01 01 01 00  00 00 00 00 00 00 00 00  |.ELF............|
00000010  02 00 03 00 01 00 00 00  80 80 04 08 34 00 00 00  |............4...|
00000020  18 01 00 00 00 00 00 00  34 00 20 00 02 00 28 00  |........4. ...(.|
00000030  06 00 03 00 01 00 00 00  00 00 00 00 00 80 04 08  |................|
00000040  00 80 04 08 b8 00 00 00  b8 00 00 00 05 00 00 00  |................|
00000050  00 10 00 00 01 00 00 00  b8 00 00 00 b8 90 04 08  |................|
00000060  b8 90 04 08 36 00 00 00  36 00 00 00 06 00 00 00  |....6...6.......|
00000070  00 10 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
00000080  b8 04 00 00 00 bb 01 00  00 00 ba 0c 00 00 00 b9  |................|
00000090  ce 90 04 08 cd 80 b8 04  00 00 00 bb 01 00 00 00  |................|
000000a0  ba 16 00 00 00 b9 b8 90  04 08 cd 80 b8 01 00 00  |................|
000000b0  00 bb 00 00 00 00 cd 80  69 74 20 73 69 6d 70 6c  |........it simpl|
000000c0  65 2c 20 53 6d 69 74 68  69 65 73 21 0a 0a 4b 49  |e, Smithies!..KI|
000000d0  53 53 3a 20 4b 65 65 70  20 20 59 6f 75 20 67 6f  |SS: Keep  You go|
000000e0  74 20 69 74 21 0a 4e 6f  20 77 61 79 21 0a 00 2e  |t it!.No way!...|
000000f0  73 79 6d 74 61 62 00 2e  73 74 72 74 61 62 00 2e  |symtab..strtab..|
00000100  73 68 73 74 72 74 61 62  00 2e 74 65 78 74 00 2e  |shstrtab..text..|
00000110  64 61 74 61 00 00 00 00  00 00 00 00 00 00 00 00  |data............|
00000120  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
00000130  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
00000140  1b 00 00 00 01 00 00 00  06 00 00 00 80 80 04 08  |................|
00000150  80 00 00 00 38 00 00 00  00 00 00 00 00 00 00 00  |....8...........|
00000160  10 00 00 00 00 00 00 00  21 00 00 00 01 00 00 00  |........!.......|
00000170  03 00 00 00 b8 90 04 08  b8 00 00 00 36 00 00 00  |............6...|
00000180  00 00 00 00 00 00 00 00  04 00 00 00 00 00 00 00  |................|
00000190  11 00 00 00 03 00 00 00  00 00 00 00 00 00 00 00  |................|
000001a0  ee 00 00 00 27 00 00 00  00 00 00 00 00 00 00 00  |....'...........|
000001b0  01 00 00 00 00 00 00 00  01 00 00 00 02 00 00 00  |................|
000001c0  00 00 00 00 00 00 00 00  08 02 00 00 30 01 00 00  |............0...|
000001d0  05 00 00 00 0f 00 00 00  04 00 00 00 10 00 00 00  |................|
000001e0  09 00 00 00 03 00 00 00  00 00 00 00 00 00 00 00  |................|
000001f0  38 03 00 00 6c 00 00 00  00 00 00 00 00 00 00 00  |8...l...........|
00000200  01 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|
00000210  00 00 00 00 00 00 00 00  00 00 00 00 80 80 04 08  |................|
00000220  00 00 00 00 03 00 01 00  00 00 00 00 b8 90 04 08  |................|
00000230  00 00 00 00 03 00 02 00  01 00 00 00 00 00 00 00  |................|
00000240  00 00 00 00 04 00 f1 ff  15 00 00 00 01 00 00 00  |................|
00000250  00 00 00 00 00 00 f1 ff  1a 00 00 00 04 00 00 00  |................|
00000260  00 00 00 00 00 00 f1 ff  20 00 00 00 01 00 00 00  |........ .......|
00000270  00 00 00 00 00 00 f1 ff  27 00 00 00 b8 90 04 08  |........'.......|
00000280  00 00 00 00 00 00 02 00  2c 00 00 00 16 00 00 00  |........,.......|
00000290  00 00 00 00 00 00 f1 ff  32 00 00 00 ce 90 04 08  |........2.......|
000002a0  00 00 00 00 00 00 02 00  37 00 00 00 0c 00 00 00  |........7.......|
000002b0  00 00 00 00 00 00 f1 ff  3d 00 00 00 da 90 04 08  |........=.......|
000002c0  00 00 00 00 00 00 02 00  42 00 00 00 0c 00 00 00  |........B.......|
000002d0  00 00 00 00 00 00 f1 ff  48 00 00 00 e6 90 04 08  |........H.......|
000002e0  00 00 00 00 00 00 02 00  00 00 00 00 00 00 00 00  |................|
000002f0  00 00 00 00 04 00 f1 ff  4d 00 00 00 80 80 04 08  |........M.......|
00000300  00 00 00 00 10 00 01 00  54 00 00 00 ee 90 04 08  |........T.......|
00000310  00 00 00 00 10 00 02 00  60 00 00 00 ee 90 04 08  |........`.......|
00000320  00 00 00 00 10 00 02 00  67 00 00 00 f0 90 04 08  |........g.......|
00000330  00 00 00 00 10 00 02 00  00 72 65 76 65 72 73 65  |.........reverse|
00000340  45 6e 67 69 6e 65 65 72  2e 61 73 6d 00 45 58 49  |Engineer.asm.EXI|
00000350  54 00 57 52 49 54 45 00  53 54 44 4f 55 54 00 6d  |T.WRITE.STDOUT.m|
00000360  73 67 31 00 4d 53 47 31  4c 00 6d 73 67 32 00 4d  |sg1.MSG1L.msg2.M|
00000370  53 47 32 4c 00 6d 73 67  33 00 4d 53 47 33 4c 00  |SG2L.msg3.MSG3L.|
00000380  6d 73 67 34 00 5f 73 74  61 72 74 00 5f 5f 62 73  |msg4._start.__bs|
00000390  73 5f 73 74 61 72 74 00  5f 65 64 61 74 61 00 5f  |s_start._edata._|
000003a0  65 6e 64 00                                       |end.|
000003a4

...