binary bomb

This is a discussion on binary bomb within the Tech Board forums, part of the Community Boards category; i'm working on the binary bomb assignment, i've defused phase_1 bomb , but not phase_2. Please help me on doing ...

  1. #1
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    binary bomb

    i'm working on the binary bomb assignment, i've defused phase_1 bomb , but not phase_2.

    Please help me on doing so

    this following is the disassmbled code using objdump

    Code:
    08048b80 <phase_2>:
     8048b80:       55                      push   %ebp
     8048b81:       89 e5                   mov    %esp,%ebp
     8048b83:       56                      push   %esi
     8048b84:       53                      push   %ebx
     8048b85:       83 ec 30                sub    $0x30,%esp
     8048b88:       be 00 00 00 00          mov    $0x0,%esi
     8048b8d:       8d 45 d8                lea    0xffffffd8(%ebp),%eax
     8048b90:       89 44 24 04             mov    %eax,0x4(%esp)
     8048b94:       8b 45 08                mov    0x8(%ebp),%eax
     8048b97:       89 04 24                mov    %eax,(%esp)
     8048b9a:       e8 d5 03 00 00          call   8048f74 <read_six_numbers>
     8048b9f:       bb 00 00 00 00          mov    $0x0,%ebx
     8048ba4:       8b 44 9d d8             mov    0xffffffd8(%ebp,%ebx,4),%eax
     8048ba8:       3b 44 9d e4             cmp    0xffffffe4(%ebp,%ebx,4),%eax
     8048bac:       74 05                   je     8048bb3 <phase_2+0x33>
     8048bae:       e8 f2 07 00 00          call   80493a5 <explode_bomb>
     8048bb3:       03 74 9d d8             add    0xffffffd8(%ebp,%ebx,4),%esi
     8048bb7:       43                      inc    %ebx
     8048bb8:       83 fb 02                cmp    $0x2,%ebx
     8048bbb:       7e e7                   jle    8048ba4 <phase_2+0x24>
     8048bbd:       85 f6                   test   %esi,%esi
     8048bbf:       75 05                   jne    8048bc6 <phase_2+0x46>
     8048bc1:       e8 df 07 00 00          call   80493a5 <explode_bomb>
     8048bc6:       83 c4 30                add    $0x30,%esp
     8048bc9:       5b                      pop    %ebx
     8048bca:       5e                      pop    %esi
     8048bcb:       5d                      pop    %ebp
     8048bcc:       c3                      ret
    and the following using gdb

    Code:
    08048b80 <phase_2>:
     8048b80:       55                      push   %ebp
     8048b81:       89 e5                   mov    %esp,%ebp
     8048b83:       56                      push   %esi
     8048b84:       53                      push   %ebx
     8048b85:       83 ec 30                sub    $0x30,%esp
     8048b88:       be 00 00 00 00          mov    $0x0,%esi
     8048b8d:       8d 45 d8                lea    0xffffffd8(%ebp),%eax
     8048b90:       89 44 24 04             mov    %eax,0x4(%esp)
     8048b94:       8b 45 08                mov    0x8(%ebp),%eax
     8048b97:       89 04 24                mov    %eax,(%esp)
     8048b9a:       e8 d5 03 00 00          call   8048f74 <read_six_numbers>
     8048b9f:       bb 00 00 00 00          mov    $0x0,%ebx
     8048ba4:       8b 44 9d d8             mov    0xffffffd8(%ebp,%ebx,4),%eax
     8048ba8:       3b 44 9d e4             cmp    0xffffffe4(%ebp,%ebx,4),%eax
     8048bac:       74 05                   je     8048bb3 <phase_2+0x33>
     8048bae:       e8 f2 07 00 00          call   80493a5 <explode_bomb>
     8048bb3:       03 74 9d d8             add    0xffffffd8(%ebp,%ebx,4),%esi
     8048bb7:       43                      inc    %ebx
     8048bb8:       83 fb 02                cmp    $0x2,%ebx
     8048bbb:       7e e7                   jle    8048ba4 <phase_2+0x24>
     8048bbd:       85 f6                   test   %esi,%esi
     8048bbf:       75 05                   jne    8048bc6 <phase_2+0x46>
     8048bc1:       e8 df 07 00 00          call   80493a5 <explode_bomb>
     8048bc6:       83 c4 30                add    $0x30,%esp
     8048bc9:       5b                      pop    %ebx
     8048bca:       5e                      pop    %esi
     8048bcb:       5d                      pop    %ebp
     8048bcc:       c3                      ret
    Last edited by Dave_Sinkula; 09-24-2006 at 02:53 PM. Reason: Added [code][/code] tags -- learn to use them yourself.

  2. #2
    Registered User Tonto's Avatar
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    Hey, it's exactly the same. Maybe you should provide more details.

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  3. #3
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    What the OP is talking about: http://www.cs.rochester.edu/~scott/2...ments/A2.shtml

    As this appears to have more to do with assembly-level debugging than C, I /r/ a move to Tech Board.
    System: Debian Sid and FreeBSD 7.0. Both with GCC 4.3.

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  4. #4
    The Right Honourable psychopath's Avatar
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    Doesn't this violate the homework policy?
    Memorial University of Newfoundland
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  5. #5
    Dump Truck Internet valis's Avatar
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    Why don't you just replace all calls to explode_bomb with a call to the defuse function?

  6. #6
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    Quote Originally Posted by valis
    Why don't you just replace all calls to explode_bomb with a call to the defuse function?
    Read the link I posted. You're supposed to defuse the bomb by inputting passwords.

    I can't quite make up mind about this assignment though, because you could construe it as cracker-training. It's certainly walking the thin line of blasphemy. I'll leave it to the Mods to decide the legitimacy, though.
    Last edited by zx-1; 09-24-2006 at 05:15 PM.
    System: Debian Sid and FreeBSD 7.0. Both with GCC 4.3.

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  7. #7
    Registered User Frobozz's Avatar
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    I don't see how this could be considered any more cracker training than learning VBScript. Especially if a university is teaching the class. But yeah this definately would constitute a homework assignment.

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