Level Goal
The password for the next level is stored in the file data.txt, which is a hexdump of a file that has been repeatedly compressed.
Solution
$ cat data.txt
^1000
`00000000: 1f8b 0808 7151 1063 0203 6461 7461 322e ....qQ.c..data2.`
`00000010: 6269 6e00 013f 02c0 fd42 5a68 3931 4159 bin..?...BZh91AY`
`00000020: 2653 595d ed11 a800 001b ffff d8ff fde7 &SY]............`
`00000030: dff7 ffff ffcf efcf bef7 7e7f dd39 3f7f ..........~..9?.`
`00000040: fafb ffbf cfbf 3eff a9fb bf7f b001 3b1b ......>.......;.`
`00000050: 6d20 0f50 0034 0680 0000 34c2 01ea 0d34 m .P.4....4....4`
`00000060: 0000 1900 1a32 1a68 0d00 0000 0034 0000 .....2.h.....4..`
`00000070: 000d 0069 91ea 0c6d 5100 0068 00c8 000d ...i...mQ..h....`
`00000080: 0323 4340 3d40 0d0d 1a68 01a3 4c83 401a .#C@=@...h..L.@.`
`00000090: 687a 4034 0340 1a00 3468 0188 c868 34d0 hz@4.@..4h...h4.`
`000000a0: 00c8 d01a 6874 d323 40d3 d206 81a1 a680 ....ht.#@.......`
`000000b0: d0c8 0190 d034 0340 0d00 c800 01a6 991a .....4.@........`
`000000c0: 0019 3400 d000 0006 800c 4d1a 0189 a001 ..4.......M.....`
`000000d0: fc18 2890 6086 162a 8035 6a6b 3d5c 1382 ..(.`..*.5jk=\..`
`000000e0: 0a38 e6dd 214b 6fa4 3984 0192 256e e084 .8..!Ko.9...%n..`
`000000f0: ed6b ad67 3318 b07a 005d 0e21 dbd1 fb84 .k.g3..z.].!....`
`00000100: 770f 055f 0044 3086 8230 d579 2881 afe7 w.._.D0..0.y(...`
`00000110: 531e 3071 f859 eeae 01aa 1040 75cd 3c5b S.0q.Y.....@u.<[`
`00000120: f24a 16b8 34e7 43db 9e73 56a1 3d3d fd90 .J..4.C..sV.==..`
`00000130: 6bc3 47a5 4c73 af13 a324 5731 b90e 2063 k.G.Ls...$W1.. c`
`00000140: 45ef fe11 842e 03f9 b063 8f4c fb41 0a32 E........c.L.A.2`
`00000150: 8fdb 7cea 82a0 ee91 4e05 c610 088e a2da ..|.....N.......`
`00000160: 7536 2c72 1701 c248 7ab7 1fef 30f8 142c u6,r...Hz...0..,`
`00000170: 0359 539c 5a21 4e94 6a33 9d18 6120 42a0 .YS.Z!N.j3..a B.`
`00000180: 6471 a01e 42a4 da3b 6eaa 5e7e edc3 f973 dq..B..;n.^~...s`
`00000190: 2ec7 5009 a7e8 101e a3ac b344 f2bb d9e6 ..P........D....`
`000001a0: 7bd7 c5fb 18b6 92ac 9fe8 aef4 673c da0c {...........g<..`
`000001b0: 0cdb 0440 4869 1bd0 7d84 e1e5 85c2 1a60 ...@Hi..}......``
`000001c0: 701c c9ac 50ca adf7 bba9 226f f175 1ec2 p...P....."o.u..`
`000001d0: 90de 557e ed09 5c3b 1886 84dc f110 24e7 ..U~..\;......$.`
`000001e0: 871b 6148 f224 fb71 c3d1 1096 4a48 48a2 ..aH.$.q....JHH.`
`000001f0: 99ea 647b 4f3b ac19 3be6 1cb9 24c3 ce48 ..d{O;..;...$..H`
`00000200: 829b 0182 07ef fbee dff1 40da 6f5a c7fb ..........@.oZ..`
`00000210: 5412 78a9 43dd 2198 d456 3c1f e161 2b1f T.x.C.!..V<..a+.`
`00000220: 6e82 f066 70e2 67b8 ec48 d418 3e6a 0ee7 n..fp.g..H..>j..`
`00000230: 868a 1dcc e7b0 11ee 8b2a 8c53 0009 37f9 .........*.S..7.`
`00000240: 1017 0d29 485a ec30 cb90 45b8 93ff 1772 ...)HZ.0..E....r`
`00000250: 4538 5090 5ded 11a8 e965 cb22 3f02 0000 E8P.]....e."?...`
$
We can see that this file contains a hex dump. We can use the xxd utility with the -r flag to convert the hex dump back to the binary file.
$ xxd -r data.txt file.bin
^1000
$ file file.bin
^1000
`file.bin: gzip compressed data, was "data2.bin"`
$
We see that it is a gzip compressed archive, so we can use the gzip (or gunzip in this case since we are decompressing) utility. * Note that the suffix matters to the gzip utility so we will rename the archive so that it has a .gz suffix.
$ mv file.bin file.gz
^1000
$ gunzip file.gz
^1000
$ file file
^1000
`file: bzip2 compressed data, block size = 900k`
$
We see that this is a bzip2 compressed archive, so we can use the bzip2 (or bunzip2 in this case since we are decompressing) utility. * Note bzip2 doesn’t care about the suffix so we don’t need to rename it.
$ bunzip2 file
^1000
`bunzip2: Can't guess original name for file -- using file.out`
$ file file.out
^1000
`file.out: gzip compressed data, was "data4.bin"`
$ mv file.out file.gz
^1000
$ gunzip file.gz
^1000
$ file file
^1000
`file: POSIX tar archive (GNU)`
$
We see that we now have a tarball, so we can use the tar utility to extract it. The -x (extract), -v (verbose), and -f (file) flags are used.
$ tar -xvf file
^1000
`data5.bin`
$ file data5.bin
^1000
`data5.bin: POSIX tar archive (GNU)`
$ tar -xvf data5.bin
^1000
`data6.bin`
$ file data6.bin
^1000
`data6.bin: bzip2 compressed data, block size = 900k`
$ bunzip2 data6.bin
^1000
`bunzip2: Can't guess original name for data6.bin -- using data6.bin.out`
$ file data6.bin.out
^1000
`data6.bin.out: POSIX tar archive (GNU)`
$ tar -xvf data6.bin.out
^1000
`data8.bin`
$ file data8.bin
^1000
`data8.bin: gzip compressed data, was "data9.bin"`
$ mv data8.bin data8.gz
^1000
$ gunzip data8.gz
^1000
$ file data8
^1000
`data8: ASCII text`
$ cat data8
^1000
`The password is wbWdlBxEir4CaE8LaPhauuOo6pwRmrDw`
$
See the xxd, gzip, bzip2, and tar man pages for further reading.