I have a file crackme, which is an executable.
hamuto@hamuto-pc:~/Security/NOOB/FruitSalad$ file crackme
crackme: ELF 64-bit LSB pie executable, x86-64, version 1 (SYSV), dynamically linked, interpreter /lib64/ld-linux-x86-64.so.2, for GNU/Linux 3.2.0, BuildID[sha1]=5418569f8ce35c5b188b0a4f13e79f4a611ee54e, stripped
I tried to follow the instructions of the solution of the bellow question.
Reversing ELF 64-bit LSB executable, x86-64 ,gdb
Sadly, I have a problem and I can't find a solution.
What I did:
hamuto@hamuto-pc:~/Security/NOOB/FruitSalad$ gdb crackme -q
Reading symbols from crackme...
(No debugging symbols found in crackme)
gdb$ info files
Symbols from "/home/hamuto/Security/NOOB/FruitSalad/crackme".
Local exec file:
`/home/hamuto/Security/NOOB/FruitSalad/crackme', file type elf64-x86-64.
Entry point: 0x22b0
0x00000000000002a8 - 0x00000000000002c4 is .interp
0x00000000000002c4 - 0x00000000000002e4 is .note.ABI-tag
0x00000000000002e4 - 0x0000000000000308 is .note.gnu.build-id
0x0000000000000308 - 0x0000000000000340 is .gnu.hash
0x0000000000000340 - 0x0000000000000850 is .dynsym
0x0000000000000850 - 0x00000000000010d4 is .dynstr
0x00000000000010d4 - 0x0000000000001140 is .gnu.version
0x0000000000001140 - 0x00000000000011f0 is .gnu.version_r
0x00000000000011f0 - 0x0000000000001508 is .rela.dyn
0x0000000000001508 - 0x00000000000018b0 is .rela.plt
0x0000000000002000 - 0x0000000000002017 is .init
0x0000000000002020 - 0x00000000000022a0 is .plt
0x00000000000022a0 - 0x00000000000022a8 is .plt.got
0x00000000000022b0 - 0x0000000000009b81 is .text
0x0000000000009b84 - 0x0000000000009b8d is .fini
0x000000000000a000 - 0x000000000000a2da is .rodata
0x000000000000a2dc - 0x000000000000ae90 is .eh_frame_hdr
0x000000000000ae90 - 0x000000000000df70 is .eh_frame
0x000000000000df70 - 0x000000000000e25c is .gcc_except_table
0x000000000000fd10 - 0x000000000000fd28 is .init_array
0x000000000000fd28 - 0x000000000000fd30 is .fini_array
0x000000000000fd30 - 0x000000000000fdb8 is .data.rel.ro
0x000000000000fdb8 - 0x000000000000ffc8 is .dynamic
0x000000000000ffc8 - 0x0000000000010000 is .got
0x0000000000010000 - 0x0000000000010150 is .got.plt
0x0000000000010150 - 0x000000000001016c is .data
0x0000000000010180 - 0x00000000000103f0 is .bss
gdb$
As you can see the entry point is at 0x22b0. If I try to create a breakpoint and run :
gdb$ break *0x22b0
Breakpoint 1 at 0x22b0
gdb$ r
Starting program: /home/hamuto/Security/NOOB/FruitSalad/crackme
[1]+ Arrêté gdb crackme -q
hamuto@hamuto-pc:~/Security/NOOB/FruitSalad$
The program actually get to the background, I can get it back with the command fg:
hamuto@hamuto-pc:~/Security/NOOB/FruitSalad$ fg
gdb crackme -q
Warning:
Cannot insert breakpoint 1.
Cannot access memory at address 0x22b0
It is still strange, that gdb went to the background, but that's not all if I try to disassemble the entry point, with a size of 50:
gdb$ disas 0x22b0,+50
Dump of assembler code from 0x22b0 to 0x2300:
0x00000000000022b0: Cannot access memory at address 0x22b0
It doesn't work, I must be missing something. Thank you for your help.
