this binary lab phase $5,$ please give me solution to defuse the bomb

Dump of assembler code for function phase$\_5$:

$0$x$000000000040106$b $<+0>$: push $\%$rbx

$0$x$000000000040106$c $<+1>$: sub $$0$x$10,\%$rsp

$0$x$0000000000401070<+5>$: mov $\%$rdi,$\%$rbx

$0$x$0000000000401073<+8>$: callq $0$x$4012$ce

$0$x$0000000000401078<+13>$: cmp $$0$x$6,\%$eax

$0$x$000000000040107$b $<+16>$: jne $0$x$4010$bc

$0$x$000000000040107$d $<+18>$: mov $$0$x$0,\%$eax

$0$x$0000000000401082<+23>$: movzbl $(\%$rbx$,\%$rax,$1),\%$edx

$0$x$0000000000401086<+27>$: and $$0$xf$,\%$edx

$0$x$0000000000401089<+30>$: movzbl $0$x$4024$d$0(\%$rdx$),\%$edx

$0$x$0000000000401090<+37>$: mov $\%$dl$,0$x$9(\%$rsp$,\%$rax,$1)$

$0$x$0000000000401094<+41>$: add $$0$x$1,\%$rax

$0$x$0000000000401098<+45>$: cmp $$0$x$6,\%$rax

$0$x$000000000040109$c $<+49>$: jne $0$x$401082$

$0$x$000000000040109$e $<+51>$: movb $$0$x$0,0$xf$(\%$rsp$)$

$0$x$00000000004010$a$3<+56>$: mov $$0$x$40247$e$,\%$esi

$0$x$00000000004010$a$8<+61>$: lea $0$x$9(\%$rsp$),\%$rdi

$0$x$00000000004010$ad $<+66>$: callq $0$x$4012$eb

$0$x$00000000004010$b$2<+71>$: test $\%$eax,$\%$eax

$0$x$00000000004010$b$4<+73>$: jne $0$x$4010$c$3$

$0$x$00000000004010$b$6<+75>$: add $$0$x$10,\%$rsp

$0$x$00000000004010$ba $<+79>$: pop $\%$rbx

$0$x$00000000004010$bb $<+80>$: retq

$0$x$00000000004010$bc $<+81>$: callq $0$x$401512$

$0$x$00000000004010$c$1<+86>$: jmp $0$x$40107$d

$0$x$00000000004010$c$3<+88>$: callq $0$x$401512$

$0$x$00000000004010$c$8<+93>$: jmp $0$x$4010$b$6$

End of assembler dump.

$($gdb$)$ disas string$\_$length

Dump of assembler code for function string$\_$length:

$0$x$00000000004012$ce $<+0>$: cmpb $$0$x$0,(\%$rdi$)$

$0$x$00000000004012$d$1<+3>$: je $0$x$4012$e$5$

$0$x$00000000004012$d$3<+5>$: mov $$0$x$0,\%$eax

$0$x$00000000004012$d$8<+10>$: add $$0$x$1,\%$rdi

$0$x$00000000004012$dc $<+14>$: add $$0$x$1,\%$eax

$0$x$00000000004012$df $<+17>$: cmpb $$0$x$0,(\%$rdi$)$

$0$x$00000000004012$e$2<+20>$: jne $0$x$4012$d$8$

$0$x$00000000004012$e$4<+22>$: retq

$0$x$00000000004012$e$5<+23>$: mov $$0$x$0,\%$eax

$0$x$00000000004012$ea $<+28>$: retq

End of assembler dump.