写入“已解码”文件并转换为汇编。 该计划有一个数字;说50，并将其与预定义的常数进行比较：示例
>>decoded 50 //if the number is equal to the predefined constant number then you pass.
该文件作为一个名为decode的程序运行，所以我不得不使用这个命令
>>objdump -d decoded
查看汇编代码。 （下面是代码）。
我一直在查看这个汇编代码，试图弄清楚输出和内存与注册表之间的移动以及指定的值，以便在程序中找出预定义的常量以便通过。 我已经注意了$符号后面的所有值，并看到了它们的存储位置。我也注意了添加cmpl和mov。 我得到了这些价值观：
rsi是8 + 1 edi是4196104 + 1 + 4196192 + 4196240 eax是101010101010 + 0 我假设所有人都在内存中（Rbp）。
我用这些值运行程序并尝试了各种组合，但它没有让我通过。我觉得我并不完全了解汇编代码及其工作原理。
000000000040060d <main>:
40060d: 55 push %rbp
40060e: 48 89 e5 mov %rsp,%rbp
400611: 48 83 ec 20 sub $0x20,%rsp
400615: 89 7d ec mov %edi,-0x14(%rbp)
400618: 48 89 75 e0 mov %rsi,-0x20(%rbp)
40061c: c7 45 fc 12 eb 34 3c movl $0x3c34eb12,-0x4(%rbp)
400623: 83 7d ec 01 cmpl $0x1,-0x14(%rbp)
400627: 7f 19 jg 400642 <main+0x35>
400629: bf 08 07 40 00 mov $0x400708,%edi
40062e: b8 00 00 00 00 mov $0x0,%eax
400633: e8 98 fe ff ff callq 4004d0 <printf@plt>
400638: bf 01 00 00 00 mov $0x1,%edi
40063d: e8 ce fe ff ff callq 400510 <exit@plt>
400642: 48 8b 45 e0 mov -0x20(%rbp),%rax
400646: 48 83 c0 08 add $0x8,%rax
40064a: 48 8b 00 mov (%rax),%rax
40064d: 48 89 c7 mov %rax,%rdi
400650: e8 ab fe ff ff callq 400500 <atoi@plt>
400655: 3b 45 fc cmp -0x4(%rbp),%eax
400658: 74 0c je 400666 <main+0x59>
40065a: bf 60 07 40 00 mov $0x400760,%edi
40065f: e8 5c fe ff ff callq 4004c0 <puts@plt>
400664: eb 0a jmp 400670 <main+0x63>
400666: bf 90 07 40 00 mov $0x400790,%edi
40066b: e8 50 fe ff ff callq 4004c0 <puts@plt>
400670: c9 leaveq
400671: c3 retq
400672: 66 2e 0f 1f 84 00 00 nopw %cs:0x0(%rax,%rax,1)
400679: 00 00 00
40067c: 0f 1f 40 00 nopl 0x0(%rax)
完整的程序如下，我只关注主要功能。
Disassembly of section .init:
0000000000400488 <_init>:
400488: 48 83 ec 08 sub $0x8,%rsp
40048c: 48 8b 05 65 0b 20 00 mov 0x200b65(%rip),%rax # 600ff8 <_DYNAMIC+0x1d0>
400493: 48 85 c0 test %rax,%rax
400496: 74 05 je 40049d <_init+0x15>
400498: e8 53 00 00 00 callq 4004f0 <__gmon_start__@plt>
40049d: 48 83 c4 08 add $0x8,%rsp
4004a1: c3 retq
Disassembly of section .plt:
00000000004004b0 <puts@plt-0x10>:
4004b0: ff 35 52 0b 20 00 pushq 0x200b52(%rip) # 601008 <_GLOBAL_OFFSET_TABLE_+0x8>
4004b6: ff 25 54 0b 20 00 jmpq *0x200b54(%rip) # 601010 <_GLOBAL_OFFSET_TABLE_+0x10>
4004bc: 0f 1f 40 00 nopl 0x0(%rax)
00000000004004c0 <puts@plt>:
4004c0: ff 25 52 0b 20 00 jmpq *0x200b52(%rip) # 601018 <_GLOBAL_OFFSET_TABLE_+0x18>
4004c6: 68 00 00 00 00 pushq $0x0
4004cb: e9 e0 ff ff ff jmpq 4004b0 <_init+0x28>
00000000004004d0 <printf@plt>:
4004d0: ff 25 4a 0b 20 00 jmpq *0x200b4a(%rip) # 601020 <_GLOBAL_OFFSET_TABLE_+0x20>
4004d6: 68 01 00 00 00 pushq $0x1
4004db: e9 d0 ff ff ff jmpq 4004b0 <_init+0x28>
00000000004004e0 <__libc_start_main@plt>:
4004e0: ff 25 42 0b 20 00 jmpq *0x200b42(%rip) # 601028 <_GLOBAL_OFFSET_TABLE_+0x28>
4004e6: 68 02 00 00 00 pushq $0x2
4004eb: e9 c0 ff ff ff jmpq 4004b0 <_init+0x28>
00000000004004f0 <__gmon_start__@plt>:
4004f0: ff 25 3a 0b 20 00 jmpq *0x200b3a(%rip) # 601030 <_GLOBAL_OFFSET_TABLE_+0x30>
4004f6: 68 03 00 00 00 pushq $0x3
4004fb: e9 b0 ff ff ff jmpq 4004b0 <_init+0x28>
0000000000400500 <atoi@plt>:
400500: ff 25 32 0b 20 00 jmpq *0x200b32(%rip) # 601038 <_GLOBAL_OFFSET_TABLE_+0x38>
400506: 68 04 00 00 00 pushq $0x4
40050b: e9 a0 ff ff ff jmpq 4004b0 <_init+0x28>
0000000000400510 <exit@plt>:
400510: ff 25 2a 0b 20 00 jmpq *0x200b2a(%rip) # 601040 <_GLOBAL_OFFSET_TABLE_+0x40>
400516: 68 05 00 00 00 pushq $0x5
40051b: e9 90 ff ff ff jmpq 4004b0 <_init+0x28>
Disassembly of section .text:
0000000000400520 <_start>:
400520: 31 ed xor %ebp,%ebp
400522: 49 89 d1 mov %rdx,%r9
400525: 5e pop %rsi
400526: 48 89 e2 mov %rsp,%rdx
400529: 48 83 e4 f0 and $0xfffffffffffffff0,%rsp
40052d: 50 push %rax
40052e: 54 push %rsp
40052f: 49 c7 c0 f0 06 40 00 mov $0x4006f0,%r8
400536: 48 c7 c1 80 06 40 00 mov $0x400680,%rcx
40053d: 48 c7 c7 0d 06 40 00 mov $0x40060d,%rdi
400544: e8 97 ff ff ff callq 4004e0 <__libc_start_main@plt>
400549: f4 hlt
40054a: 66 0f 1f 44 00 00 nopw 0x0(%rax,%rax,1)
0000000000400550 <deregister_tm_clones>:
400550: b8 5f 10 60 00 mov $0x60105f,%eax
400555: 55 push %rbp
400556: 48 2d 58 10 60 00 sub $0x601058,%rax
40055c: 48 83 f8 0e cmp $0xe,%rax
400560: 48 89 e5 mov %rsp,%rbp
400563: 77 02 ja 400567 <deregister_tm_clones+0x17>
400565: 5d pop %rbp
400566: c3 retq
400567: b8 00 00 00 00 mov $0x0,%eax
40056c: 48 85 c0 test %rax,%rax
40056f: 74 f4 je 400565 <deregister_tm_clones+0x15>
400571: 5d pop %rbp
400572: bf 58 10 60 00 mov $0x601058,%edi
400577: ff e0 jmpq *%rax
400579: 0f 1f 80 00 00 00 00 nopl 0x0(%rax)
0000000000400580 <register_tm_clones>:
400580: b8 58 10 60 00 mov $0x601058,%eax
400585: 55 push %rbp
400586: 48 2d 58 10 60 00 sub $0x601058,%rax
40058c: 48 c1 f8 03 sar $0x3,%rax
400590: 48 89 e5 mov %rsp,%rbp
400593: 48 89 c2 mov %rax,%rdx
400596: 48 c1 ea 3f shr $0x3f,%rdx
40059a: 48 01 d0 add %rdx,%rax
40059d: 48 d1 f8 sar %rax
4005a0: 75 02 jne 4005a4 <register_tm_clones+0x24>
4005a2: 5d pop %rbp
4005a3: c3 retq
4005a4: ba 00 00 00 00 mov $0x0,%edx
4005a9: 48 85 d2 test %rdx,%rdx
4005ac: 74 f4 je 4005a2 <register_tm_clones+0x22>
4005ae: 5d pop %rbp
4005af: 48 89 c6 mov %rax,%rsi
4005b2: bf 58 10 60 00 mov $0x601058,%edi
4005b7: ff e2 jmpq *%rdx
4005b9: 0f 1f 80 00 00 00 00 nopl 0x0(%rax)
00000000004005c0 <__do_global_dtors_aux>:
4005c0: 80 3d 91 0a 20 00 00 cmpb $0x0,0x200a91(%rip) # 601058 <__TMC_END__>
4005c7: 75 11 jne 4005da <__do_global_dtors_aux+0x1a>
4005c9: 55 push %rbp
4005ca: 48 89 e5 mov %rsp,%rbp
4005cd: e8 7e ff ff ff callq 400550 <deregister_tm_clones>
4005d2: 5d pop %rbp
4005d3: c6 05 7e 0a 20 00 01 movb $0x1,0x200a7e(%rip) # 601058 <__TMC_END__>
4005da: f3 c3 repz retq
4005dc: 0f 1f 40 00 nopl 0x0(%rax)
00000000004005e0 <frame_dummy>:
4005e0: 48 83 3d 38 08 20 00 cmpq $0x0,0x200838(%rip) # 600e20 <__JCR_END__>
4005e7: 00
4005e8: 74 1e je 400608 <frame_dummy+0x28>
4005ea: b8 00 00 00 00 mov $0x0,%eax
4005ef: 48 85 c0 test %rax,%rax
4005f2: 74 14 je 400608 <frame_dummy+0x28>
4005f4: 55 push %rbp
4005f5: bf 20 0e 60 00 mov $0x600e20,%edi
4005fa: 48 89 e5 mov %rsp,%rbp
4005fd: ff d0 callq *%rax
4005ff: 5d pop %rbp
400600: e9 7b ff ff ff jmpq 400580 <register_tm_clones>
400605: 0f 1f 00 nopl (%rax)
400608: e9 73 ff ff ff jmpq 400580 <register_tm_clones>
000000000040060d <main>:
40060d: 55 push %rbp
40060e: 48 89 e5 mov %rsp,%rbp
400611: 48 83 ec 20 sub $0x20,%rsp
400615: 89 7d ec mov %edi,-0x14(%rbp)
400618: 48 89 75 e0 mov %rsi,-0x20(%rbp)
40061c: c7 45 fc 12 eb 34 3c movl $0x3c34eb12,-0x4(%rbp)
400623: 83 7d ec 01 cmpl $0x1,-0x14(%rbp)
400627: 7f 19 jg 400642 <main+0x35>
400629: bf 08 07 40 00 mov $0x400708,%edi
40062e: b8 00 00 00 00 mov $0x0,%eax
400633: e8 98 fe ff ff callq 4004d0 <printf@plt>
400638: bf 01 00 00 00 mov $0x1,%edi
40063d: e8 ce fe ff ff callq 400510 <exit@plt>
400642: 48 8b 45 e0 mov -0x20(%rbp),%rax
400646: 48 83 c0 08 add $0x8,%rax
40064a: 48 8b 00 mov (%rax),%rax
40064d: 48 89 c7 mov %rax,%rdi
400650: e8 ab fe ff ff callq 400500 <atoi@plt>
400655: 3b 45 fc cmp -0x4(%rbp),%eax
400658: 74 0c je 400666 <main+0x59>
40065a: bf 60 07 40 00 mov $0x400760,%edi
40065f: e8 5c fe ff ff callq 4004c0 <puts@plt>
400664: eb 0a jmp 400670 <main+0x63>
400666: bf 90 07 40 00 mov $0x400790,%edi
40066b: e8 50 fe ff ff callq 4004c0 <puts@plt>
400670: c9 leaveq
400671: c3 retq
400672: 66 2e 0f 1f 84 00 00 nopw %cs:0x0(%rax,%rax,1)
400679: 00 00 00
40067c: 0f 1f 40 00 nopl 0x0(%rax)
0000000000400680 <__libc_csu_init>:
400680: 41 57 push %r15
400682: 41 89 ff mov %edi,%r15d
400685: 41 56 push %r14
400687: 49 89 f6 mov %rsi,%r14
40068a: 41 55 push %r13
40068c: 49 89 d5 mov %rdx,%r13
40068f: 41 54 push %r12
400691: 4c 8d 25 78 07 20 00 lea 0x200778(%rip),%r12 # 600e10 <__frame_dummy_init_array_entry>
400698: 55 push %rbp
400699: 48 8d 2d 78 07 20 00 lea 0x200778(%rip),%rbp # 600e18 <__init_array_end>
4006a0: 53 push %rbx
4006a1: 4c 29 e5 sub %r12,%rbp
4006a4: 31 db xor %ebx,%ebx
4006a6: 48 c1 fd 03 sar $0x3,%rbp
4006aa: 48 83 ec 08 sub $0x8,%rsp
4006ae: e8 d5 fd ff ff callq 400488 <_init>
4006b3: 48 85 ed test %rbp,%rbp
4006b6: 74 1e je 4006d6 <__libc_csu_init+0x56>
4006b8: 0f 1f 84 00 00 00 00 nopl 0x0(%rax,%rax,1)
4006bf: 00
4006c0: 4c 89 ea mov %r13,%rdx
4006c3: 4c 89 f6 mov %r14,%rsi
4006c6: 44 89 ff mov %r15d,%edi
4006c9: 41 ff 14 dc callq *(%r12,%rbx,8)
4006cd: 48 83 c3 01 add $0x1,%rbx
4006d1: 48 39 eb cmp %rbp,%rbx
4006d4: 75 ea jne 4006c0 <__libc_csu_init+0x40>
4006d6: 48 83 c4 08 add $0x8,%rsp
4006da: 5b pop %rbx
4006db: 5d pop %rbp
4006dc: 41 5c pop %r12
4006de: 41 5d pop %r13
4006e0: 41 5e pop %r14
4006e2: 41 5f pop %r15
4006e4: c3 retq
4006e5: 66 66 2e 0f 1f 84 00 data32 nopw %cs:0x0(%rax,%rax,1)
4006ec: 00 00 00 00
00000000004006f0 <__libc_csu_fini>:
4006f0: f3 c3 repz retq
Disassembly of section .fini:
00000000004006f4 <_fini>:
4006f4: 48 83 ec 08 sub $0x8,%rsp
4006f8: 48 83 c4 08 add $0x8,%rsp
4006fc: c3 retq