# ▼▼▼Gateway(LuciferVM:25)、316/948team＝33.3%▼▼▼**This writeup is written by [@kazkiti_ctf](https://twitter.com/kazkiti_ctf)**
--- ```Once you have the password to the VM archive, you will still need to get the decryption password to the root drive. This is the gateway challenge, and it can be found in the only unencrypted partition on the drive.The decryption password does NOT include TUCTF{}, but the flag does.
Hint dumpDownload newest binaryRun stringsUse tool```
【他】
・`bcea5034bd8dbfd6dd9e30b929f9c123`ファイルが提供されている。
-----
`$ strings bcea5034bd8dbfd6dd9e30b929f9c123 `
```/lib64/ld-linux-x86-64.so.2libc.so.6puts__stack_chk_failstdinprintffgets__cxa_finalize__libc_start_mainGLIBC_2.4GLIBC_2.2.5_ITM_deregisterTMCloneTable__gmon_start___ITM_registerTMCloneTableAWAVIAUATL[]A\A]A^A_GHPGS{JrypbzrOnpx,Unpxrezna}A Multi-Purpose Utility for Calculating the ROT13 of StringsThere is no other purpose of this tool.Please enter your string: Your ROT13-ed String is: %sThank you for using this simple tool.This tool exists only for this purpose.There are no secrets contained within this tool.Eventually, you'll give up reading this garbage, right?Even I wouldn't waste time on this.Good luck on the REAL challenge.Literally all it does is take up space.Obviously, this is a distraction.Finally! A secret hidden flag!Currently, it will literally do nothing outside of padding the file.Turns out UPX packer REQUIRES a binary to be at least 40kbsUnfortunately, this function will now exist.To be sure, you may be thinking to yourself:{Spoilers, it's not}For real though, go solve the challenge so you can get on to the cool stuff.Anyone could write this garbage, why would it be a secret.Here you go, more garbage.Really, it is just wasting space.}-: Or not I guess, up to you.NOTHING HERE.AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA;*3$"GCC: (GNU) 7.2.0init.ccrtstuff.cderegister_tm_clones__do_global_dtors_auxcompleted.6973__do_global_dtors_aux_fini_array_entryframe_dummy__frame_dummy_init_array_entrygate.c__FRAME_END____init_array_end_DYNAMIC__init_array_start__GNU_EH_FRAME_HDR_GLOBAL_OFFSET_TABLE___libc_csu_finirandomPaddingFunctionwelcomeLine1_ITM_deregisterTMCloneTableputs@@GLIBC_2.2.5stdin@@GLIBC_2.2.5_edatarot13__stack_chk_fail@@GLIBC_2.4printf@@GLIBC_2.2.5datapad__libc_start_main@@GLIBC_2.2.5fgets@@GLIBC_2.2.5__data_start__gmon_start____dso_handle_IO_stdin_usedsketchyString__libc_csu_initdatapad2__bss_startmainexitLine1__TMC_END___ITM_registerTMCloneTable__cxa_finalize@@GLIBC_2.2.5.symtab.strtab.shstrtab.interp.note.ABI-tag.note.gnu.build-id.gnu.hash.dynsym.dynstr.gnu.version.gnu.version_r.rela.dyn.rela.plt.init.text.fini.rodata.eh_frame_hdr.eh_frame.init_array.fini_array.dynamic.got.got.plt.data.bss.comment```
↓
`GHPGS{JrypbzrOnpx,Unpxrezna}`
↓rot13でデコード
```GHPGS{JrypbzrOnpx,Unpxrezna}HIQHT{KszqcAsPoqy,VoqysfAob}IJRIU{LtArdBtQprz,WprztgBpc}JKSJV{MuBseCuRqsA,XqsAuhCqd}KLTKW{NvCtfDvSrtB,YrtBviDre}LMULX{OwDugEwTsuC,ZsuCwjEsf}MNVMY{PxEvhFxUtvD,atvDxkFtg}NOWNZ{QyFwiGyVuwE,buwEylGuh}OPXOa{RzGxjHzWvxF,cvxFzmHvi}PQYPb{SAHykIAXwyG,dwyGAnIwj}QRZQc{TBIzlJBYxzH,exzHBoJxk}RSaRd{UCJAmKCZyAI,fyAICpKyl}STbSe{VDKBnLDazBJ,gzBJDqLzm}TUcTf{WELCoMEbACK,hACKErMAn} ●UVdUg{XFMDpNFcBDL,iBDLFsNBo}VWeVh{YGNEqOGdCEM,jCEMGtOCp}WXfWi{ZHOFrPHeDFN,kDFNHuPDq}XYgXj{aIPGsQIfEGO,lEGOIvQEr}YZhYk{bJQHtRJgFHP,mFHPJwRFs}ZaiZl{cKRIuSKhGIQ,nGIQKxSGt}abjam{dLSJvTLiHJR,oHJRLyTHu}bckbn{eMTKwUMjIKS,pIKSMzUIv}cdlco{fNULxVNkJLT,qJLTNAVJw}demdp{gOVMyWOlKMU,rKMUOBWKx}efneq{hPWNzXPmLNV,sLNVPCXLy}fgofr{iQXOAYQnMOW,tMOWQDYMz}ghpgs{jRYPBZRoNPX,uNPXREZNA}hiqht{kSZQCaSpOQY,vOQYSFaOB}ijriu{lTaRDbTqPRZ,wPRZTGbPC}jksjv{mUbSEcUrQSa,xQSaUHcQD}kltkw{nVcTFdVsRTb,yRTbVIdRE}lmulx{oWdUGeWtSUc,zSUcWJeSF}mnvmy{pXeVHfXuTVd,ATVdXKfTG}nownz{qYfWIgYvUWe,BUWeYLgUH}opxoA{rZgXJhZwVXf,CVXfZMhVI}pqypB{sahYKiaxWYg,DWYgaNiWJ}qrzqC{tbiZLjbyXZh,EXZhbOjXK}rsArD{ucjaMkczYai,FYaicPkYL}stBsE{vdkbNldAZbj,GZbjdQlZM}tuCtF{welcOmeBack,HackeRmaN}●uvDuG{xfmdPnfCbdl,IbdlfSnbO}vwEvH{ygneQogDcem,JcemgTocP}wxFwI{zhofRphEdfn,KdfnhUpdQ}xyGxJ{AipgSqiFego,LegoiVqeR}yzHyK{BjqhTrjGfhp,MfhpjWrfS}zAIzL{CkriUskHgiq,NgiqkXsgT}ABJAM{DlsjVtlIhjr,OhjrlYthU}BCKBN{EmtkWumJiks,PiksmZuiV}CDLCO{FnulXvnKjlt,QjltnavjW}DEMDP{GovmYwoLkmu,RkmuobwkX}EFNEQ{HpwnZxpMlnv,SlnvpcxlY}FGOFR{IqxoayqNmow,TmowqdymZ}```
↓
TUcTf{WELCoMEbACK,hACKErMAn} ⇒　incorrect!!
tuCtF{welcOmeBack,HackeRmaN} ⇒　incorrect!!
↓
小文字は小文字のままrot13、大文字は大文字のままrot13する。
`TUCTF{WelcomeBack,Hackerman}`