C 第三阶段二元炸弹组件
我在反汇编这段代码时遇到了很大的困难。我理解函数调用3个输入,1个十进制和2个字符。我得出的结论是小数点是7,尽管我不能完全肯定这是正确的。我知道我必须在某个地方使用跳转表,我相信它在0x08048d50,我同样希望进行一些验证和更正,但我不确定如何键入命令C 第三阶段二元炸弹组件,c,debugging,assembly,gdb,C,Debugging,Assembly,Gdb,我在反汇编这段代码时遇到了很大的困难。我理解函数调用3个输入,1个十进制和2个字符。我得出的结论是小数点是7,尽管我不能完全肯定这是正确的。我知道我必须在某个地方使用跳转表,我相信它在0x08048d50,我同样希望进行一些验证和更正,但我不确定如何键入命令 Dump of assembler code for function phase_3: 0x08048cfa <+0>: push %ebp 0x08048cfb <+1>: mov %esp
Dump of assembler code for function phase_3:
0x08048cfa <+0>: push %ebp
0x08048cfb <+1>: mov %esp,%ebp
0x08048cfd <+3>: sub $0x38,%esp
=> 0x08048d00 <+6>: movl $0x0,-0xc(%ebp)
0x08048d07 <+13>: lea -0x12(%ebp),%eax
0x08048d0a <+16>: mov %eax,0x10(%esp)
0x08048d0e <+20>: lea -0x13(%ebp),%eax
0x08048d11 <+23>: mov %eax,0xc(%esp)
0x08048d15 <+27>: lea -0x10(%ebp),%eax
0x08048d18 <+30>: mov %eax,0x8(%esp)
0x08048d1c <+34>: movl $0x804a7ff,0x4(%esp)
0x08048d24 <+42>: mov 0x8(%ebp),%eax
0x08048d27 <+45>: mov %eax,(%esp)
0x08048d2a <+48>: call 0x8048960 <__isoc99_sscanf@plt>
0x08048d2f <+53>: mov %eax,-0xc(%ebp)
0x08048d32 <+56>: cmpl $0x2,-0xc(%ebp)
0x08048d36 <+60>: jg 0x8048d3d <phase_3+67>
0x08048d38 <+62>: call 0x8049675 <explode_bomb>
0x08048d3d <+67>: mov -0x10(%ebp),%eax
0x08048d40 <+70>: cmp $0x7,%eax
0x08048d43 <+73>: ja 0x8048e56 <phase_3+348>
0x08048d49 <+79>: mov 0x804a808(,%eax,4),%eax
0x08048d50 <+86>: jmp *%eax
0x08048d52 <+88>: movb $0x6d,-0x11(%ebp)
0x08048d56 <+92>: movzbl -0x12(%ebp),%eax
0x08048d5a <+96>: movsbl %al,%eax
0x08048d5d <+99>: lea 0x20(%eax),%edx
0x08048d60 <+102>: movsbl -0x11(%ebp),%eax
0x08048d64 <+106>: cmp %eax,%edx
0x08048d66 <+108>: je 0x8048e61 <phase_3+359>
0x08048d6c <+114>: call 0x8049675 <explode_bomb>
0x08048d71 <+119>: jmp 0x8048e61 <phase_3+359>
0x08048d76 <+124>: movb $0x68,-0x11(%ebp)
0x08048d7a <+128>: movzbl -0x12(%ebp),%eax
0x08048d7e <+132>: movsbl %al,%eax
0x08048d81 <+135>: lea 0x20(%eax),%edx
0x08048d84 <+138>: movsbl -0x11(%ebp),%eax
---Type <return> to continue, or q <return> to quit---
0x08048d88 <+142>: cmp %eax,%edx
0x08048d8a <+144>: je 0x8048e64 <phase_3+362>
0x08048d90 <+150>: call 0x8049675 <explode_bomb>
0x08048d95 <+155>: jmp 0x8048e64 <phase_3+362>
0x08048d9a <+160>: movb $0x63,-0x11(%ebp)
0x08048d9e <+164>: movzbl -0x12(%ebp),%eax
0x08048da2 <+168>: movsbl %al,%eax
0x08048da5 <+171>: lea 0x20(%eax),%edx
0x08048da8 <+174>: movsbl -0x11(%ebp),%eax
0x08048dac <+178>: cmp %eax,%edx
0x08048dae <+180>: je 0x8048e67 <phase_3+365>
0x08048db4 <+186>: call 0x8049675 <explode_bomb>
0x08048db9 <+191>: jmp 0x8048e67 <phase_3+365>
0x08048dbe <+196>: movb $0x6f,-0x11(%ebp)
0x08048dc2 <+200>: movzbl -0x12(%ebp),%eax
0x08048dc6 <+204>: movsbl %al,%eax
0x08048dc9 <+207>: lea 0x20(%eax),%edx
0x08048dcc <+210>: movsbl -0x11(%ebp),%eax
0x08048dd0 <+214>: cmp %eax,%edx
0x08048dd2 <+216>: je 0x8048e6a <phase_3+368>
0x08048dd8 <+222>: call 0x8049675 <explode_bomb>
0x08048ddd <+227>: jmp 0x8048e6a <phase_3+368>
0x08048de2 <+232>: movb $0x6d,-0x11(%ebp)
0x08048de6 <+236>: movzbl -0x12(%ebp),%eax
0x08048dea <+240>: movsbl %al,%eax
0x08048ded <+243>: lea 0x20(%eax),%edx
0x08048df0 <+246>: movsbl -0x11(%ebp),%eax
0x08048df4 <+250>: cmp %eax,%edx
0x08048df6 <+252>: je 0x8048e6d <phase_3+371>
0x08048df8 <+254>: call 0x8049675 <explode_bomb>
0x08048dfd <+259>: jmp 0x8048e6d <phase_3+371>
0x08048dff <+261>: movb $0x76,-0x11(%ebp)
0x08048e03 <+265>: movzbl -0x12(%ebp),%eax
0x08048e07 <+269>: movsbl %al,%eax
0x08048e0a <+272>: lea 0x20(%eax),%edx
0x08048e0d <+275>: movsbl -0x11(%ebp),%eax
0x08048e11 <+279>: cmp %eax,%edx
0x08048e13 <+281>: je 0x8048e70 <phase_3+374>
---Type <return> to continue, or q <return> to quit---
0x08048e15 <+283>: call 0x8049675 <explode_bomb>
0x08048e1a <+288>: jmp 0x8048e70 <phase_3+374>
0x08048e1c <+290>: movb $0x70,-0x11(%ebp)
0x08048e20 <+294>: movzbl -0x12(%ebp),%eax
0x08048e24 <+298>: movsbl %al,%eax
0x08048e27 <+301>: lea 0x20(%eax),%edx
0x08048e2a <+304>: movsbl -0x11(%ebp),%eax
0x08048e2e <+308>: cmp %eax,%edx
0x08048e30 <+310>: je 0x8048e73 <phase_3+377>
0x08048e32 <+312>: call 0x8049675 <explode_bomb>
0x08048e37 <+317>: jmp 0x8048e73 <phase_3+377>
0x08048e39 <+319>: movb $0x6f,-0x11(%ebp)
0x08048e3d <+323>: movzbl -0x12(%ebp),%eax
0x08048e41 <+327>: movsbl %al,%eax
0x08048e44 <+330>: lea 0x20(%eax),%edx
0x08048e47 <+333>: movsbl -0x11(%ebp),%eax
0x08048e4b <+337>: cmp %eax,%edx
0x08048e4d <+339>: je 0x8048e76 <phase_3+380>
0x08048e4f <+341>: call 0x8049675 <explode_bomb>
0x08048e54 <+346>: jmp 0x8048e76 <phase_3+380>
0x08048e56 <+348>: movb $0x69,-0x11(%ebp)
0x08048e5a <+352>: call 0x8049675 <explode_bomb>
0x08048e5f <+357>: jmp 0x8048e77 <phase_3+381>
0x08048e61 <+359>: nop
0x08048e62 <+360>: jmp 0x8048e77 <phase_3+381>
0x08048e64 <+362>: nop
0x08048e65 <+363>: jmp 0x8048e77 <phase_3+381>
0x08048e67 <+365>: nop
0x08048e68 <+366>: jmp 0x8048e77 <phase_3+381>
0x08048e6a <+368>: nop
0x08048e6b <+369>: jmp 0x8048e77 <phase_3+381>
0x08048e6d <+371>: nop
0x08048e6e <+372>: jmp 0x8048e77 <phase_3+381>
0x08048e70 <+374>: nop
0x08048e71 <+375>: jmp 0x8048e77 <phase_3+381>
0x08048e73 <+377>: nop
0x08048e74 <+378>: jmp 0x8048e77 <phase_3+381>
0x08048e76 <+380>: nop
功能阶段_3的汇编程序代码转储:
0x08048cfa:推送%ebp
0x08048cfb:mov%esp,%ebp
0x08048cfd:子$0x38,%esp
=>0x08048d00:movl$0x0,-0xc(%ebp)
0x08048d07:lea-0x12(%ebp),%eax
0x08048d0a:mov%eax,0x10(%esp)
0x08048d0e:lea-0x13(%ebp),%eax
0x08048d11:mov%eax,0xc(%esp)
0x08048d15:lea-0x10(%ebp),%eax
0x08048d18:mov%eax,0x8(%esp)
0x08048d1c:movl$0x804a7ff,0x4(%esp)
0x08048d24:mov 0x8(%ebp),%eax
0x08048d27:mov%eax,(%esp)
0x08048d2a:调用0x8048960
0x08048d2f:mov%eax,-0xc(%ebp)
0x08048d32:cmpl$0x2,-0xc(%ebp)
0x08048d36:jg 0x8048d3d
0x08048d38:调用0x8049675
0x08048d3d:mov-0x10(%ebp),%eax
0x08048d40:cmp$0x7,%eax
0x08048d43:ja 0x8048e56
0x08048449:mov 0x804a808(,%eax,4),%eax
0x08048d50:jmp*%eax
0x08048d52:movb$0x6d,-0x11(%ebp)
0x08048d56:movzbl-0x12(%ebp),%eax
0x08048d5a:movsbl%al,%eax
0x08048d5d:lea 0x20(%eax),%edx
0x08048d60:movsbl-0x11(%ebp),%eax
0x08048464:cmp%eax,%edx
0x08048d66:je 0x8048e61
0x08048d6c:调用0x8049675
0x08048d71:jmp 0x8048e61
0x08048d76:movb$0x68,-0x11(%ebp)
0x08048d7a:movzbl-0x12(%ebp),%eax
0x08048d7e:movsbl%al,%eax
0x08048d81:lea 0x20(%eax),%edx
0x08048d84:movsbl-0x11(%ebp),%eax
---键入以继续,或键入q以退出---
0x08048d88:cmp%eax,%edx
0x08048A:je 0x8048e64
0x08048d90:调用0x8049675
0x08048d95:jmp 0x8048e64
0x08048d9a:movb$0x63,-0x11(%ebp)
0x08048d9e:movzbl-0x12(%ebp),%eax
0x08048da2:movsbl%al,%eax
0x08048da5:lea 0x20(%eax),%edx
0x08048da8:movsbl-0x11(%ebp),%eax
0x08048dac:cmp%eax,%edx
0x08048dae:je 0x8048e67
0x08048db4:调用0x8049675
0x08048db9:jmp 0x8048e67
0x08048dbe:movb$0x6f,-0x11(%ebp)
0x08048dc2:movzbl-0x12(%ebp),%eax
0x08048dc6:movsbl%al,%eax
0x08048dc9:lea 0x20(%eax),%edx
0x08048dcc:movsbl-0x11(%ebp),%eax
0x08048dd0:cmp%eax,%edx
0x08048dd2:je 0x8048e6a
0x08048dd8:调用0x8049675
0x08048ddd:jmp 0x8048e6a
0x08048de2:movb$0x6d,-0x11(%ebp)
0x08048de6:movzbl-0x12(%ebp),%eax
0x08048dea:movsbl%al,%eax
0x08048ded:lea 0x20(%eax),%edx
0x08048df0:movsbl-0x11(%ebp),%eax
0x08048df4:cmp%eax,%edx
0x08048df6:je 0x8048e6d
0x08048df8:调用0x8049675
0x08048dfd:jmp 0x8048e6d
0x08048dff:movb$0x76,-0x11(%ebp)
0x08048e03:movzbl-0x12(%ebp),%eax
0x08048e07:movsbl%al,%eax
0x08048e0a:lea 0x20(%eax),%edx
0x08048e0d:movsbl-0x11(%ebp),%eax
0x08048e11:cmp%eax,%edx
0x08048e13:je 0x8048e70
---键入以继续,或键入q以退出---
0x08048e15:调用0x8049675
0x08048e1a:jmp 0x8048e70
0x08048e1c:movb$0x70,-0x11(%ebp)
0x08048e20:movzbl-0x12(%ebp),%eax
0x08048e24:movsbl%al,%eax
0x08048e27:lea 0x20(%eax),%edx
0x08048e2a:movsbl-0x11(%ebp),%eax
0x08048e2e:cmp%eax,%edx
0x08048e30:je 0x8048e73
0x08048e32:调用0x8049675
0x08048e37:jmp 0x8048e73
0x08048e39:movb$0x6f,-0x11(%ebp)
0x08048e3d:movzbl-0x12(%ebp),%eax
0x08048e41:movsbl%al,%eax
0x08048e44:lea 0x20(%eax),%edx
0x08048e47:movsbl-0x11(%ebp),%eax
0x08048e4b:cmp%eax,%edx
0x08048e4d:je 0x8048e76
0x08048e4f:调用0x8049675
0x08048e54:jmp 0x8048e76
0x08048e56:movb$0x69,-0x11(%ebp)
0x08048e5a:调用0x8049675
0x08048e5f:jmp 0x8048e77
0x08048e61:否
0x08048e62:jmp 0x8048e77
0x08048e64:否
0x08048e65:jmp 0x8048e77
0x08048e67:否
0x08048e68:jmp 0x8048e77
0x08048e6a:否
0x08048e6b:jmp 0x8048e77
0x08048e6d:否
0x08048e6e:jmp 0x8048e77
0x08048e70:否
0x08048e71:jmp 0x8048e77
0x08048e73:否
0x08048e74:jmp 0x8048e77
0x08048e76:否
0x08048d49:mov 0x804a808(,%eax,4),%eax
此语法表示:将0x804a808+4*%eax
移动到%eax
中。这将帮助您确定下一行中的跳转地址
0x08048d49 <+79>: mov 0x804a808(,%eax,4),%eax