20150501: Hacky Easter 2015 - writeup

Search out the password in the image

• anagram(missing letters {a,c,e,h,k,r,z}) = hackerz

New York Times, March 12 2015
An Easter Egg of the famous Hacky Easter white-hat hacking competition, was leaked last Tuesday by the famous hacker group "Bunnonymous". Experts confirmed its authenticity, but could not crack the code hidden it in yet.

Can you do better?

• QR code != img, but = HTML table
• clue in puzzle title: "media" ie. CSS @media
• inspect CSS styling in HTML src style: class='h5' styled differently when page is printed

…
.x5 { height: 4%; width: 4%; background: #fff;}
@media print {
	…
	.x5 { height: 4%; width: 4%; background: #000;}
}

• simply print the page to reveal QR code for this level

You intercepted a message sent by a nerd from the office nearby. On first sight, there's nothing suspicious in it. However, you are almost sure that something secret must be hidden in it. Can you find out what?

legostego.lxf

• fmt: .lxf ‐ open-with: LEGO Digital Designer
• obs. 3 layers present
• QR code in *mid* layer ie. strip off top layer
• 

Calculate/convert the following values, and sort them in ascending order

• xs = [1400,9671406559999999577423872,299792458,2130706433,36.4621596072,2147483647,13631488,1048576,50,36,100000,261.626]
• sorted(zip(xs,xrange(1,len(xs)+1)))
• sorted in ascending order:
10. 36
5. 36.4621596072
9. 50
12. 261.626
1. 1400
11. 100000
8. 1048576
7. 13631488
3. 299792458
4. 2130706433
6. 2147483647
2. 9.67140656 × 10²⁴
• extract original indices:
• map(lambda (x,y): y, sorted(zip(xs,xrange(1,len(xs)+1))))
• var h = "10,5,9,12,1,11,8,7,3,4,6,2";
• for (var i=0; i<10000; i++) {h = CryptoJS.SHA1(h);} decryptScrambledEggWithKey('' + h);…

In this challenge, you need to play with your phone a bit. Try to find out what controls the four bars, and make them reach the full width (all at the same time).

• extract & decompile APK
• @ /assets/www/challenge05.html:
• requestLevels is invoked every 1000ms to query ps://sensors endpt
• sensorFeedback(json) sets lvls by parsing JSON response vars {l1,l2,l3,l4,k}

…
function requestLevels() {
	window.location.href="ps://sensors";
}
function sensorFeedback(json) {
	var jsonResp = JSON.parse(json);
	setLevel(1, jsonResp.l1);
	setLevel(2, jsonResp.l2);
	setLevel(3, jsonResp.l3);
	setLevel(4, jsonResp.l4);
	if (jsonResp.k) {
		decryptScrambledEggWithKey(jsonResp.k);
		clearInterval(intervalId);
	}
}
var intervalId = setInterval(requestLevels, 1000);
…

• ps://sensors is mentioned @/src/ps/hacking/hackyeaster/android/c.java

…
	if ("ps://sensors".equals(s))
	{
		Activity.e(a);
		return true;
	}
…

• static e(Activity a) is defined @ /src/ps/hacking/hackyeaster/android/Activity.java

private SensorManager g;
…
static void e(Activity activity)
{
	activity.d();
}
private void d()
{
	h = g.getDefaultSensor(1); //TYPE_ACCELEROMETER
	i = g.getDefaultSensor(2); //TYPE_MAGNETIC_FIELD
	g.registerListener(this, h, 0);
	g.registerListener(this, i, 0);
	…
}
public int c()
{
	Intent intent = registerReceiver(null, new IntentFilter("android.intent.action.BATTERY_CHANGED")); //current battery level
	int i1 = intent.getIntExtra("level", -1);
	int j1 = intent.getIntExtra("scale", -1);
	if (i1 == -1 || j1 == -1)
	{
		return 50;
	} else
	{
		return Math.round((i1 * 100) / j1); // to %
	}
}
private void j()
{
	int i1 = 100;
	if (l == null || m == null) goto _L2; else goto _L1
_L1:
	float af[] = new float[9];
	if (!SensorManager.getRotationMatrix(af, new float[9], l, m)) goto _L2; else goto _L3
_L3:
	float af1[] = new float[3];
	SensorManager.getOrientation(af, af1);
	int j1 = 5 * (int)Math.ceil((double)((int)(System.currentTimeMillis() / 1000L) % 100) / 5D);
	int k1 = Math.round(100F * (Math.abs(af1[1]) + Math.abs(af1[2])));
	int l1;
	int i2;
	int j2;
	int k2;
	String s;
	String s1;
	MessageDigest messagedigest;
	String s2;
	if (k1 <= 20)
	{
		l1 = i1;
	} else
	if (k1 > 300)
	{
		l1 = 0;
	} else
	{
		l1 = Math.round((100 * (300 - k1)) / 280);
	}
	i2 = Math.round(100F * Math.abs(af1[0]));
	if (i2 <= 20)
	{
		j2 = i1;
	} else
	{
		j2 = 0;
		if (i2 <= 300)
		{
			j2 = Math.round((100 * (300 - i2)) / 280);
		}
	}
	k2 = c();
	Exception exception;
	if (k2 < 95)
	{
		i1 = k2;
	}
	s = "";
	if (i1 + (j2 + (j1 + l1)) != 400)
	{
		break MISSING_BLOCK_LABEL_246;
	}
	s1 = (new StringBuilder(String.valueOf(j1))).append("f").append(l1).append("u").append(j2).append("n").append(i1).toString();
	messagedigest = MessageDigest.getInstance("SHA1");
	messagedigest.update(s1.getBytes());
	s2 = Base64.encodeToString(messagedigest.digest(), 2);
	s = s2;
_L5:
	a.loadUrl((new StringBuilder("javascript:sensorFeedback('{\"k\": \"")).append(s).append("\", \"l1\": ").append(j1).append(", \"l2\": ").append(l1).append(", \"l3\": ").append(j2).append(", \"l4\": ").append(i1).append("}')").toString());
	l = null;
	m = null;
_L2:
	return;
	exception;
	if (true) goto _L5; else goto _L4
_L4:
}
public void onSensorChanged(SensorEvent sensorevent)
{
	if (sensorevent.sensor.getType() == 1) //TYPE_ACCELEROMETER
	{
		l = sensorevent.values;
		g.unregisterListener(this, h);
		h = null;
	}
	if (sensorevent.sensor.getType() == 2) //TYPE_MAGNETIC_FIELD
	{
		m = sensorevent.values;
		g.unregisterListener(this, i);
		i = null;
	}
	j();
}
…

• Activity: e(a) → d() → callback-onSensorChanged() → j() → c() → ret
• mapping: sensorFeedback({k: s, l1: j1, l2: l1, l3: j2, l4: i1}), where:
• s = base64(SHA1(j1+"f"+l1+"u"+j2+"n"+i1))

1. Current time
2. Accelerometer
3. Compass
4. Battery percentage

The Doc's in trouble again, and you must come to his rescue! As you jump into his time machine, you realize that a password is needed to start it. Just in that moment of despair, you receive an audio message from the Doc, through space and time:

dah-dah-dit dit dah-dah-dah di-dah-dit dah-dah-dit dit dah-dah dah-di-dah-dit di-di-dah-dit di-dah-di-dit dah-di-dah-dah

• Python Morse code decoder

#!/usr/bin/env python

import sys
import codecs

if __name__ == "__main__":
	morse_lookup = {"dah": "T", "dah-dah": "M", "dah-dah-dah": "O", "dah-dah-dit": "G", "dah-dah-dit-dah": "Q", "dah-dah-dit-dit": "Z", "dah-dit": "N", "dah-dit-dah": "K", "dah-di-dah-dah": "Y", "dah-di-dah-dit": "C", "dah-dit-dit": "D", "dah-dit-dit-dah": "X", "dah-dit-dit-dit": "B", "dit": "E", "dit-dah": "A", "dit-dah-dah": "W", "dit-dah-dah-dah": "J", "dit-dah-dah-dit": "P", "di-dah-dit": "R", "di-dah-di-dit": "L", "dit-dit": "I", "dit-dit-dah": "U", "di-di-dah-dit": "F", "dit-dit-dit": "S", "dit-dit-dit-dah": "V", "dit-dit-dit-dit": "H"}
	ms = "dah-dah-dit dit dah-dah-dah di-dah-dit dah-dah-dit dit dah-dah dah-di-dah-dit di-di-dah-dit di-dah-di-dit dah-di-dah-dah"
	print "".join(morse_lookup[m] for m in ms.split()).lower()

• georgemcfly
• not quite done yet! enter georgemcfly into Egg-O-Matic performs a HTTP GET request to http://hackyeaster.hacking-lab.com/hackyeaster/time?m=4&k=georgemcfly
• rendering:
• so need to modify HTTP GET param m, according to given hint in img, by +3 ie. m=7
• curl -sL "http://hackyeaster.hacking-lab.com/hackyeaster/time?m=7&k=georgemcfly" | jq -r '.egg' | base64 -d

This egg is hidden in a street-view like viewer. Peek around the area and find it!

• extract & decompile APK reveals:
  • query ps://panorama endpt
  • usage of PanoramaGL Library
• QR code @ /res/raw/quito2_u.jpg

This egg is hidden within an online spreadsheet. Go find it's URL, and extract the egg out of it.

Spreadsheet ID:
1QPkfrnSVRAhQKL7AZx_HVXWrRXDvwCnVX2ih0jYp1CA

• @ https://docs.google.com/spreadsheets/d/1QPkfrnSVRAhQKL7AZx_HVXWrRXDvwCnVX2ih0jYp1CA

0	19	3	22	4	11	20	6	1	9	25	10	23	5	12	13	7	15	16	17	18	14	21	8	2	24
3	1	1	1	1	1	0	0	1	0	1	1	1	1	1	0	1	1	0	1	0	0	1	0	0	0
19	1	1	0	1	0	0	1	1	1	1	1	0	1	1	1	1	0	0	1	0	0	1	0	1	1
10	0	1	0	1	0	1	0	1	0	0	1	0	0	0	0	0	1	0	1	0	0	0	0	0	0
1	1	1	1	1	0	1	1	1	0	1	1	1	1	0	0	1	1	1	1	0	0	1	0	1	1
21	1	1	1	1	1	1	0	1	1	1	1	1	1	1	0	1	0	1	1	1	0	1	0	0	1
22	1	1	0	1	1	0	0	1	1	1	0	0	1	0	1	1	1	1	1	1	1	0	0	0	1
8	0	0	0	0	0	0	0	0	0	0	0	0	0	0	1	0	0	1	1	0	0	0	0	0	0
16	0	1	0	0	1	1	0	1	1	0	0	0	0	0	1	0	0	1	1	1	1	1	0	0	0
4	1	1	1	1	0	0	0	1	1	1	1	1	1	1	0	1	0	1	1	0	1	1	0	0	0
2	1	0	0	0	0	0	0	1	1	1	1	0	0	1	1	1	0	1	0	0	0	0	0	0	0
12	0	1	0	1	1	0	0	1	0	0	1	0	0	1	0	0	1	1	1	1	0	0	0	0	0
11	1	0	0	0	0	0	0	1	0	1	1	1	1	1	1	1	0	1	0	0	1	1	1	1	1
25	0	1	1	1	0	1	1	1	1	1	0	0	1	0	1	1	1	0	0	0	0	1	0	1	1
24	0	0	0	0	0	1	0	1	1	1	0	0	0	0	1	1	0	0	0	1	1	1	0	0	0
7	1	1	1	1	1	1	1	1	1	1	0	1	1	0	1	1	1	0	1	0	0	1	0	1	1
20	0	0	0	0	1	0	0	1	0	1	0	0	0	1	0	1	1	0	1	0	0	1	0	0	0
5	1	1	1	1	1	0	0	1	0	1	0	1	1	0	1	1	1	0	1	0	0	1	0	0	0
18	0	0	1	0	1	0	0	0	1	1	1	1	0	0	0	0	0	1	1	0	0	1	0	0	0
14	1	0	1	1	1	1	1	1	0	0	1	1	0	0	1	0	0	1	1	1	1	0	1	1	1
13	1	0	0	0	0	1	0	1	0	1	1	0	1	1	0	1	0	1	0	1	0	1	1	0	1
17	1	1	0	0	1	1	1	1	1	1	1	0	1	0	1	1	1	0	1	1	0	1	0	0	0
23	0	1	1	1	0	1	0	1	1	1	1	0	1	0	0	1	1	1	0	0	1	0	0	0	0
15	1	0	1	1	1	0	0	1	0	1	0	1	1	0	0	1	1	1	0	0	1	1	0	0	0
6	1	0	0	0	1	0	0	1	1	1	0	0	0	0	0	1	0	1	0	0	0	0	0	0	0
9	0	1	1	1	1	1	0	1	1	0	1	0	1	0	1	1	0	0	0	1	1	0	1	1	1

• task: sort row + col # (highlighted in red), together with their associated row/col entries respectively, in asc order
• copy/paste HTML tbl above into lvl08-grid.txt

#!/usr/bin/env python
#-*- coding: utf-8 -*-

import sys
import codecs
from PIL import Image

sys.stdout = codecs.getwriter("utf8")(sys.stdout)
sys.stderr = codecs.getwriter("utf8")(sys.stderr)

def parse(filepath):
	row_idx, col_idx, grid = [], [], []
	with codecs.open(filepath, "r", "utf-8") as f:
		for i, line in enumerate(f):
			line = line.strip()
			if not line: continue
			if i == 0:
				col_idx = map(int, line.split("\t"))[1:]
				col_idx = map(lambda i: i-1, col_idx)
				length = len(col_idx)
				grid = [[0 for x in xrange(length)] for x in xrange(length)]
			else:
				toks = map(int, line.split("\t"))
				row_idx.append(toks[0]-1)
				toks = toks[1:]
				for j in xrange(length):
					grid[i-1][j] = toks[j]
	grid_tmp = [[0 for x in xrange(length)] for x in xrange(length)]
	for i,c in enumerate(col_idx):
		for j in xrange(length):
			grid_tmp[j][c] = grid[j][i]
	for i,r in enumerate(row_idx):
		for j in xrange(length):
			grid[r][j] = grid_tmp[i][j]
	# for i in xrange(length):
	# 	for j in xrange(length):
	# 		print>>sys.stderr, str(grid[i][j])+"\t",
	# 	print>>sys.stderr
	return grid

def enlarge(grid):
	length = len(grid)
	if length > 0: length = min(length, len(grid[0]))
	grid_large = [[0 for x in xrange(length*length)] for x in xrange(length*length)]
	for i in xrange(length):
		for j in xrange(length):
			for x in xrange(length):
				for y in xrange(length):
					grid_large[i*length+x][j*length+y] = grid[i][j]
	return grid_large

def save(grid, outfile):
	length = len(grid)
	if length > 0: length = min(length, len(grid[0]))
	im1 = Image.new("RGB", (length,length))
	pix1 = im1.load()
	w, h = im1.size
	for i in xrange(h):
	    for j in xrange(w):
	   		pix1[j,i] = tuple([(1-grid[i][j])*255]*3)
	im1.save(outfile, outfile.split(".")[-1].upper())
	return im1

if __name__ == "__main__":
	grid = parse("lvl08-grid.txt")
	grid = enlarge(grid)
	save(grid, "lvl08-grid.png")

Egg number nine is hidden here in the app. You've already seen it, haven't you?

Go catch it and squint like a fish.

• img @ /res/drawable/id_launcher.png
• correct fisheye by following a GIMP tutorial

In order to get this egg, you need to search on the web site. Rumors say that Thumper himself has bagged it.

• under "Eggs"
• (change) name to Thumper
• 

You caught a Thunderbird mail box, which contains an easter egg. Go find it!

Mail.zip

• in file Inbox, search for attachment:"signature.zip"
• carve signature.zip via its base64-encoding
  
  pbpaste | base64 -d >signature.zip
• egg can be found inside archive: unzip -l signature.zip

Archive:  signature.zip
  Length      Date    Time    Name
---------  ---------- -----   ----
    64915  09-17-2014 20:20   egg_11.png
---------                     -------
    64915                     1 file

• given form is messed up, eg.
  • Q2: specifies numeric-only
  • Q3: max-width = 3
  • Q4: uses radio btn; only allowed ≤ 1 option
  • Q5: correct port # is not one of the choices
• correct ans to given qns
1. nmap
2. revocation
3. 100*(100-1)/2 = 4950
4. 384, 512
5. 88
+ <button type="submit" name="success" value="false">Submit Test</button>
• curl -sL -X POST "http://hackyeaster.hacking-lab.com/hackyeaster/ceh" -d "q1=nmap&q2=revocation&q3=4950&q4=384&q4=512&q5=88&success=true" returns:

…
	Congratulations, you passed!!!
	<div class="eggImage" style="background-image: url('./images/egg_12_an8snbui1FeLO3Ugw89N.png')"></div>
…

• wget "http://hackyeaster.hacking-lab.com/hackyeaster/images/egg_12_an8snbui1FeLO3Ugw89N.png"

Welcome to Leet TV! Click the image below to play our trailer

• extract stills from leettv.mp4@30fps: ffmpeg -i file/leettv.mp4 -vf fps=30 leettv@%d.png
• decode QR codes in these imgs: zbarimg -q leettv@[0-9]*.png | sed 's|^QR-Code:||g' | sort | uniq >>leettv-qrcode.lst
• note leettv-qrcode.lst entry: http://bit.ly/1BJENx8
• → http://hackyeaster.hacking-lab.com/hackyeaster/leettv_qbEtJZKLTLB3jByIWSpE.wav
• exiftool leettv_qbEtJZKLTLB3jByIWSpE.wav

Title  : The Hint
Comment: siht esrever ot yrt

• echo -ne "siht esrever ot yrt" | rev says "try to reverse this"
• so follow as instructed: sox leettv_qbEtJZKLTLB3jByIWSpE.wav leettv_qbEtJZKLTLB3jByIWSpE-rev.wav reverse
• audio content: eight forty-two
• so extract frame leettv.mp4@08:42: ffmpeg -i file/leettv.mp4 -ss 00:08:42.001 -vframes 1 leettv@0842.png
• 

Wise Rabbit says:

An egg I give you for free,
it's below, as you can see.
But something got lost
add a dimension you must!

• 
• upload egg_14.png to QR code decoder
• 
• txt = yckgKB2iV1rvNEfCoNiR
• gen QR code(txt) via jQuery.qrcode

Your gallery needs some nice easter snapshots! What about a nice grasslands panorama, or a still life of a tomato?

• lol...taking a photo using mobile device's camera creates:
• 
• extract & decompile APK
• @ /src/ps/hacking/hackyeaster/android/Activity.java

…
protected void onActivityResult(int i1, int j1, Intent intent)
{
	super.onActivityResult(i1, j1, intent);
	if (i1 != 1336) goto _L2; else goto _L1
_L1:
	f = false;
	if (j1 != -1 || intent == null || !"ps.hacking.zxing.client.android.SCAN".equals(intent.getAction())) goto _L4; else goto _L3
_L3:
	a(intent);
_L6:
	return;
_L4:
	a(2, "");
	return;
_L2:
	if (i1 != 1337) goto _L6; else goto _L5
_L5:
	File file;
	file = new File(Environment.getExternalStorageDirectory(), "HackyEaster");
	if (!file.exists() && !file.mkdirs())
	{
		Toast.makeText(this, "Couldn't create folder on sdcard.", 0).show();
	}
	if (!file.exists() || intent == null || intent.getExtras() == null) goto _L6; else goto _L7
_L7:
	File file1;
	Bitmap bitmap;
	Bitmap bitmap1;
	Canvas canvas;
	int k1;
	int l1;
	long l2;
	long l3;
	long l4;
	int i2;
	file1 = new File(file, (new StringBuilder("Snapshot_")).append(e.nextInt()).append(".png").toString());
	bitmap = (Bitmap)intent.getExtras().get("data");
	bitmap1 = bitmap.copy(android.graphics.Bitmap.Config.ARGB_8888, true);
	canvas = new Canvas(bitmap1);
	k1 = bitmap.getHeight();
	l1 = bitmap.getWidth();
	l2 = 0L;
	l3 = 0L;
	l4 = 0L;
	i2 = 0;
_L8:
	if (i2 >= l1)
	{
		int j2;
		int k2;
		String as[];
		if (k1 > l1 && (double)l2 > 0.90000000000000002D * (double)(l3 + l4))
		{
			byte abyte2[] = Base64.decode(Base64.decode(j, 0), 0);
			Bitmap bitmap4 = BitmapFactory.decodeByteArray(abyte2, 0, abyte2.length);
			int k3 = bitmap4.getHeight();
			canvas.drawBitmap(bitmap4, (l1 - bitmap4.getWidth()) / 2, k1 - k3 / 2, null);
		} else
		if (l1 > k1 && (double)l3 > 0.90000000000000002D * (double)(l4 + l2))
		{
			byte abyte1[] = Base64.decode(Base64.decode(j, 0), 0);
			Bitmap bitmap3 = BitmapFactory.decodeByteArray(abyte1, 0, abyte1.length);
			int j3 = bitmap3.getHeight();
			canvas.drawBitmap(bitmap3, (l1 - bitmap3.getWidth()) / 2, -j3 / 2, null);
		} else
		{
			byte abyte0[] = Base64.decode(k, 0);
			Bitmap bitmap2 = BitmapFactory.decodeByteArray(abyte0, 0, abyte0.length);
			int i3 = bitmap2.getHeight();
			canvas.drawBitmap(bitmap2, (l1 - bitmap2.getWidth()) / 2, (k1 - i3) / 2, null);
		}
		try
		{
			FileOutputStream fileoutputstream = new FileOutputStream(file1);
			bitmap1.compress(android.graphics.Bitmap.CompressFormat.PNG, 100, fileoutputstream);
			fileoutputstream.flush();
			fileoutputstream.close();
		}
		catch (Exception exception) { }
		as = new String[1];
		as[0] = file1.toString();
		MediaScannerConnection.scanFile(this, as, null, new e(this));
		return;
	}
	j2 = 0;
label0:
	{
		if (j2 < k1)
		{
			break label0;
		}
		i2++;
	}
	  goto _L8
	k2 = bitmap.getPixel(i2, j2);
	l2 += Color.red(k2);
	l3 += Color.green(k2);
	l4 += Color.blue(k2);
	j2++;
	break MISSING_BLOCK_LABEL_383;
}
…
public void onCreate(Bundle bundle)
	{
		super.onCreate(bundle);
		j = getString(0x7f080007);
		k = getString(0x7f080008);
		if (!isTaskRoot())
		{
			Intent intent = getIntent();
			String s = intent.getAction();
			if (intent.hasCategory("android.intent.category.LAUNCHER") && s != null && s.equals("android.intent.action.MAIN"))
			{
				super.finish();
				return;
			}
		}
		ps.hacking.hackyeaster.android.i.a(this);
		a();
		g = (SensorManager)getSystemService("sensor");
		b();
		a.setOnKeyListener(new a(this, this));
	}
…

• this seems to be the routine in Activity.java responsible for the functionality here
• j and k look particularly interesting
• @ /src/ps/hacking/hackyeaster/android/R$string.java (inner class string within generated android.R)

public static final int ft = 0x7f080007;
public static final int rick = 0x7f080008;

• String constants for j=0x7f080007 and k=0x7f080008 are ft and rick respectively (rick = Rick Astley, whose face is on the photo taken)
• time to lookup the (base64-encoded) string vals @ /res/values/strings.xml; just for ft only !

<string name="ft"> … </string>

• remember to base64 --decode 2x !

import java.io.*;
import java.lang.*;
import java.util.*;
import org.apache.commons.io.*;

class Challenge15 {
	public static void main(String[] args) throws Exception
	{
		File file_ft= new File("file/lvl15-ft.base64");
		String ft = FileUtils.readFileToString(file_ft);
		byte[] decoded = org.apache.commons.codec.binary.Base64.decodeBase64(
			org.apache.commons.codec.binary.Base64.decodeBase64(
				ft.getBytes()
			));
		String filename = "lvl15-qr.png";
		FileOutputStream output = new FileOutputStream(new File(filename));
		IOUtils.write(decoded, output);
		System.out.println("=> "+filename);
	}
}

Ghosts only come out when it's dark...

• 
• turn off the lights: click on light bulb in far lower right corner @ webpage footer
• 
• JS code snippet implementing this behaviour:

function (){skelD=!skelD,skelD?($("#dark").show(),$("#chall16 img").attr("src","images/banner_challenge_16_dark.jpg"),$("#chall16 a").attr("href","challenge16-dark.html")):($("#dark").hide(),$("#chall16 img").attr("src","images/banner_challenge_16.jpg"),$("#chall16 a").attr("href","challenge16.html"))}

• clicking on Challenge 16 now leads to challenge16-dark.html, containing another puzzle desc:

Dark is beautiful. A GOST with chaining appears and has a message for you:
d5++xytj6RiGwmqEecm63Kow7RZGAAHh
VFsksHFuj/Anap7pWHDZ1XQw8DAApUEN
R5ExOGUKTzGOtvSAlCHkHq6NneL6ZUTX
ej8Taxz+kHK9w9U8dxTOSksZ4HKS2YYD

• as given in img, key: spooky; using GOST Russian symmetric key block cipher (GOST 28147-89) in Cipher Block Chaining (CBC) mode of op on ciphertxt, joined as a single contiguous string
• 

#!/usr/bin/env php

<?
	$key = "spooky"; while(strlen($key)<32) {$key.="\0";}
	$ciphertxt = "d5++xytj6RiGwmqEecm63Kow7RZGAAHhVFsksHFuj/Anap7pWHDZ1XQw8DAApUENR5ExOGUKTzGOtvSAlCHkHq6NneL6ZUTXej8Taxz+kHK9w9U8dxTOSksZ4HKS2YYD";
	$ciphertxt_b64 = base64_decode($ciphertxt);
	$iv_size = mcrypt_get_iv_size(MCRYPT_GOST, MCRYPT_MODE_CBC);
	$iv = ""; while(strlen($iv)<$iv_size) {$iv.="\0";}
	$plaintxt = mcrypt_decrypt(MCRYPT_GOST, $key, $ciphertxt_b64, MCRYPT_MODE_CBC, $iv);
	echo "key: $key".PHP_EOL;
	echo "ciphertxt: $ciphertxt".PHP_EOL;
	echo "plaintxt: $plaintxt".PHP_EOL;
?>

• @ http://hackyeaster.hacking-lab.com/hackyeaster/images/egg_16_a3eIIACKSy02sJ6LxXeh.png

Sharpen your eyes, and diff 2 img below

• QR code is always the flag in these series of challenges;
• so can guess must somehow convert 2 input img → single B/W img
• normalise to B/W using transformation:
• pix @ corresponding pos match = 0 ie. RGB(0,0,0) = black,
• pix @ corresponding pos mismatch = 1 ie. RGB(255,255,255) = white

#!/usr/bin/env python
#-*- coding: utf-8 -*-

import sys
import codecs
import operator
import numpy as np
from PIL import Image, ImageFilter

def mk_agent_xor():
	im1 = Image.open("img/difference1.bmp").convert("RGB")
	#np.asarray(im1)
	pix1s = im1.load()
	im2 = Image.open("img/difference2.bmp").convert("RGB")
	pix2s = im2.load()
	w1, h1 = im1.size
	for y in xrange(h1):
		for x in xrange(w1):
			pix1 = pix1s[x,y]
			pix2 = pix2s[x,y]
			if pix1 != pix2:
				pix1s[x,y] = (255,255,255)
			else:
				pix1s[x,y] = (0,0,0)
	im1.save("difference0.bmp")

• 
• XOR (as instructed) QR code w/ target , each found on one side of Agent's glasses, yields

#!/usr/bin/env python
#-*- coding: utf-8 -*-

import sys
import codecs
import operator
import numpy as np
from PIL import Image, ImageFilter

def crop_agent_xor():
	im = Image.open("difference0.bmp").convert("RGB")
	#qr#
	left, top, right, bottom = 245, 140, 280, 175
	img = im.crop((left, top, right, bottom))
	#img = im.filter(ImageFilter.{BLUR,CONTOUR,DETAIL,EDGE_ENHANCE,EDGE_ENHANCE_MORE,EMBOSS,FIND_EDGES,SMOOTH,SMOOTH_MORE,SHARPEN})
	#img.thumbnail(sz)
	#img.show()
	img.save("img/lvl17-qr1.jpg")
	#tgt#
	left, top, right, bottom = 333, 140, 368, 175
	img = im.crop((left, top, right, bottom))
	img.save("img/lvl17-qr2.jpg")

def mk_qr_code():
	im1 = Image.open("img/lvl17-qr1.jpg").convert("RGB")
	#im1.getcolors(), im1.format, im1.size, im1.mode
	im2 = Image.open("img/lvl17-qr2.jpg").convert("RGB")
	pix2s = list(im2.getdata())
	w2, h2 = im2.size
	pix2s = [pix2s[i*w2:(i+1)*w2] for i in xrange(h2)]
	pix1s = im1.load()
	w1, h1 = im1.size
	for y in xrange(h1):
		for x in xrange(w1):
			pix1 = pix1s[x,y]
			pix2 = pix2s[x][y]
			pix = []
			for ci in xrange(len(pix1)):
				pix.append(pix1[ci] ^ pix2[ci])
			pix1s[x,y] = tuple(pix)
	im1.save("img/lvl17-qr.jpg")

In this challenge, you need to get access to a website

Inspect sharks.pcapng, in order to get the credentials needed

• view sharks.pcapng in WireShark
• apply bpf filter: tcp stream eq 3
• Follow (this) TCP Stream
• filter for only 10.11.0.52:62046 → 10.11.0.48:8080
• 
• 
• Credentials: sharkman:sharks_have_j4ws
• curl -sL -u sharkman:sharks_have_j4ws -H "Authorization: Basic c2hhcmttYW46c2hhcmtzX2hhdmVfajR3cw==" -X POST "http://hackyeaster.hacking-lab.com/hackyeaster/sharks/auth" -d "user=supershark&pass=hashed%21%21%21&hash=b3f3ca462d3fa58b74d6982af14d8841b074994a"

…
  <body>
	<div class="title">Sharks on Wire</div>
	<div class="imageBg">
	  <img src="egg_18_j9rU8ma6nBfz986gJZmf.png" class="image"/>
	</div>
  </body>
…

• curl -sL -u sharkman:sharks_have_j4ws -H "Authorization: Basic c2hhcmttYW46c2hhcmtzX2hhdmVfajR3cw==" "http://hackyeaster.hacking-lab.com/hackyeaster/sharks/egg_18_j9rU8ma6nBfz986gJZmf.png" -o egg_18_j9rU8ma6nBfz986gJZmf.png

Time for paper and scissors! The PDF contains some paper strips. Your task is to combine them in such a way that a passphrase appears

Hint: The passphrase does *not* use all characters available, and it has no spaces

• egg img containing QR code is encrypted using AES; 256-bit key len; op in CBC mode, then base64-encoded
• following Python script gen all possible valid str combo, assuming:
  • all given paper strips have to be used
  • all letters that appear on paper strips are used in passphrase
  • no symbols are found in passphrase, as they are obscured

#!/usr/bin/env python
#-*- coding: utf-8 -*-

import sys
import codecs
import string
import itertools
from functools32 import lru_cache

def gen_wordlst(charset, maxlen):
	files = {}
	for letter in charset:
		files[letter] = open("c19-wordlist%d-%c"%(maxlen,letter), "w")
	for w in itertools.product(charset, repeat=maxlen):
		print>>files[w[0]], "".join(w)
	for v in files.values():
		if v:
			print>>sys.stderr, "=>", v.name
			v.close()

horzs = ["s.a.e", "eldpr", "qt.ia", "pupar", "ny.hs"]
verts = ["lr.se", "epdke", ".por.", ".sob.", "ahmed"]
def mkstrip(is_horz=True, mode=1):
	strips = []
	for p in itertools.permutations(horzs if is_horz else verts):
		pp = [["" for x in xrange(5)] for x in xrange(5)]
		for i,s in enumerate(p):
			for j,c in enumerate(s):
				if is_horz:
					pp[i][j] = c
				else: #vert
					pp[j][i] = c
		if mode == 1:
			pp = ["".join(p) for p in pp]
		else:
			pp = "".join("".join(p) for p in pp)
		strips.append(pp)
	return strips

def perm_horz(width=5):
	"""permute horizontal strips to form grid
		width: # grids to layout on same line
	"""

	strips = mkstrip(is_horz=True, mode=1)
	for i in xrange(0,len(strips),width):
		hh = []
		for j in xrange(len(strips[i])):
			hh = []
			for k in xrange(width):
				if i+k < len(strips):
					hh.append(strips[i+k][j])
			print "\t".join(hh).replace(".", " ")
		print

def perm_vert(width=5):
	"""permute vertical strips to form grid
		width: # grids to layout on same line
	"""

	strips = mkstrip(is_horz=False, mode=1)
	for i in xrange(0,len(strips),width):
		vv = []
		for j in xrange(len(strips[i])):
			vv = []
			for k in xrange(width):
				if i+k < len(strips):
					vv.append(strips[i+k][j])
			print "\t".join(vv).replace(".", " ")
		print

@lru_cache(maxsize=None)
def align_build(a,b,c,s):
	""" recursively build all possible valid str
		from given a,b
	"""

	if c == min(len(a),len(b)): return s
	ss = []
	if a[c] != ".":
		r = align_build(a,b,c+1,""+s+a[c])
		if r: ss.append(r)
	if b[c] != ".":
		r = align_build(a,b,c+1,""+s+b[c])
		if r: ss.append(r)
	return "\n".join(ss)

def align(idx):
	""" gen str by align-merge horz+vert strip
		from cartesian pdt of horz + vert strips
		- simulate overlap of horz + vert strips
	"""

	horzd = mkstrip(is_horz=True, mode=2)
	vertd = mkstrip(is_horz=False, mode=2)
	# print "|horzd|=", len(horzd), ";|vertd|=", len(vertd) #120
	# for hs in horzd: print "".join(hs).replace(".", " ")
	# print
	# for vs in vertd: print "".join(vs).replace(".", " ")
	for i,ab in enumerate(itertools.product(horzd, vertd)):
		if i == int(idx): #idx((a,b))
			a, b = ab
			res = align_build(a,b,0,"")
			if len(res) > 0:
				print "".join(res)
				break

if __name__ == "__main__":
	# gen_wordlst("abdehiklmnopqrstuy", 5)
	# perm_horz()
	# perm_vert()
	idx = 10290 #paperstripsmadebyshredder found @ this idx
	if len(sys.argv)>1: idx = int(sys.argv[1])
	align(idx)

• apply word segmentation via
  • eg. echo paperstripsmadebyshredder | python -m wordsegment
  • ⇒ papers trips made by shredder
  • it is evident that this approach is not perfect
  • but can at least offer some insight into possible words that can be made from the given paper strips
  • to string together, to form a sensible passphrase
• passphrase: "paper strips made by shredder"
• 
• paperstripsmadebyshredder

Robots have placed an egg on this web server. If you wanna find it, you need to think and act like a bot

• @ http://hackyeaster.hacking-lab.com/robots.txt

User-agent: EasterBot
Disallow: /
Allow: /hackyeaster/bots/bots.

User-agent: *
Disallow: /

• visit @ http://hackyeaster.hacking-lab.com/hackyeaster/bots/bots.html, supplying HTTP header: {"User-agent": "EasterBot"}

  curl -sL -A "EasterBot" "http://hackyeaster.hacking-lab.com/hackyeaster/bots/bots.html"

<html>
<head><title>Bots</title>
<script type="text/javascript">
/**
	// @ http://matthewfl.com/unPacker.html
	if (!(navigator.userAgent === 'EasterBot'))
	{
		location.replace('http://en.wikipedia.org/wiki/C-3PO');
	}
*/
eval(String.fromCharCode(105, 102, 32, 40, 33, 40, 110, 97, 118, 105, 103, 97, 116, 111, 114, 46, 117, 115, 101, 114, 65, 103, 101, 110, 116, 32, 61, 61, 61, 32, 39, 69, 97, 115, 116, 101, 114, 66, 111, 116, 39, 41, 41, 32, 123, 32, 108, 111, 99, 97, 116, 105, 111, 110, 46, 114, 101, 112, 108, 97, 99, 101, 40, 39, 104, 116, 116, 112, 58, 47, 47, 101, 110, 46, 119, 105, 107, 105, 112, 101, 100, 105, 97, 46, 111, 114, 103, 47, 119, 105, 107, 105, 47, 67, 45, 51, 80, 79, 39, 41, 59, 125));</script></head>
<body style="background: white; border: 20px solid white;">
	<div style="width: 100%; height: 100%; background: url('./robotbg.jpg') no-repeat center center fixed; -webkit-background-size: contain; -moz-background-size: contain; -o-background-size: contain; background-size: contain;">&#160;</div>
</body></html>


• Robot Interaction Language (ROILA)
• for w in bama waboki pisal fatatu fomu wosebi seju sowu seju bamas mufe wafub fomu mowewe; do egrep "^${w}\b" file/roila-wordlist.txt; done | cut -f2 | tr '\n' ' '

you must make word of addition two and two this be name of page

• ie. 2+2 = four.html

---

• visit @ http://hackyeaster.hacking-lab.com/hackyeaster/bots/four.html, supplying HTTP header: {"User-agent": "EasterBot"}

  curl -sL -A "EasterBot" "http://hackyeaster.hacking-lab.com/hackyeaster/bots/four.html"

<html>
  <head>
	<title>Bots</title>
	<meta name="description" content="Robots talk in ROILA language: eman egap eht esrever tsum">
	<meta name="keywords" content="secret, page, robots, fun, hacky easter, blrt, five, beep">
	…
  </head>
  <body style="background: white; border: 20px solid white;">
	<div style="width: 100%; height: 100%; background: url('./robotbg2.jpg') no-repeat center center fixed; -webkit-background-size: contain; -moz-background-size: contain; -o-background-size: contain; background-size: contain;">&#160;</div>
  </body>
</html>


• using MeTA (hint), together with attr:content of <meta name="description">: eman egap eht esrever tsum
• reverse string: eman egap eht esrever tsum via echo -ne "eman egap eht esrever tsum" | rev yields: must reverse the page name
• so reverse(page name = four) = ruof.html

…
  <body style="background: white; border: 20px solid white;">
	<div style="position: absolute; left:50%; top: 50%; margin-left: -187px; margin-top: -187px; width: 375px; height: 375px; background: url('./egg_20_j5fir8U6g8.png'); background-size: 375px 375px; background-repeat: no-repeat;">&#160;</div>
  </body>
</html>

Tired of boring QR codes, Dr. Bunny C. Easter developed an alternative. He's proudly introducing the "Cony Code" now! Crack the code in order to get another easter egg!

Hint: 110 is blue, the rest's up to you...

• blue = RGB(0,0,255) ≡ 110
• looks like bit flip ie. {0→1, 255→0}

#!/usr/bin/env python
#-*- coding: utf-8 -*-

import sys
import codecs
from PIL import Image, ImageFilter

reduced = []
im1 = Image.open("img/conycode.png").convert("RGB")
pix1s = im1.load()
w1, h1 = im1.size
for y in xrange(8,h1,17):
	xyc = []
	for x in xrange(8,w1,17):
		pix1 = pix1s[x,y]
		xyc.append((x,y,pix1))
	reduced.append(xyc)

ans = ""
for r in reduced:
	for xyc in r:
		_, _, pix1 = xyc
		ans += "".join(map(lambda c: "1" if c==0 else "0", list(pix1)))

print "".join(chr(int(ans[i:i+8], 2)) for i in xrange(0,len(ans),8))

prove your skills in hash cracking:

• Standard algorithms (MD5, various SHA)
• One iteration only, and no salting
• Click the hint for each hash!
• For hashes 3 and 4, use the following word list

1. Numeric PIN (16 digits)

   raLu6+eAmFelf2/uSy/67iTq57E=

   hint

   digits {0,1,7,9} are marked; assume this is charset

   hash: ada2eeebe7809857a57f6fee4b2ffaee24eae7b1

   txt: 1199019170177790

2. Single word (lowercase only)

   a791KNndKVmnr7N4mEJfZ1VfZ/Z3mHyufoYhCiyKDb38JI7C17JAEPRAutwiI7S1

   hint

   name of song by Rick Astley

   hash: 6bbf7528d9dd2959a7afb37898425f67555f67f677987cae7e86210a2c8a0dbdfc248ec2d7b24010f440badc2223b4b5

   txt: hopelessly

3. Complex word (1 upper, 1 substitution, ending with punctuation + digit)

   uAgUxeDzhrBjcWP9iv6pKQ==

   hint

   hash: b80814c5e0f386b0637163fd8afea929

   txt: Disc0very.5

4. Multi-Word (lowercase only)

   l5HL4K6RmgMwmUota6Jrjww6HaFcc7zl/KOUlYgabJA=

   hint

   hash: 9791cbe0ae919a0330994a2d6ba26b8f0c3a1da15c73bce5fca39495881a6c90

   txt: enginebulbgoatimportant

#!/usr/bin/env python
#-*- coding: utf-8 -*-

import os #os.linesep
import sys
import codecs
import hashlib
import base64
import itertools
import random
import string
import binascii

def hmatch(txt, hash):
	def name_of(var):
		import inspect
		callers_local_vars = inspect.currentframe()\
			.f_back.f_locals.items()
		return [var_name \
			for var_name, var_val in callers_local_vars \
			if var_val is var][0]
	hash = hash.lower()
	md5 = hashlib.md5(txt).hexdigest()
	sha1 = hashlib.sha1(txt).hexdigest()
	sha224 = hashlib.sha224(txt).hexdigest()
	sha256 = hashlib.sha256(txt).hexdigest()
	sha384 = hashlib.sha384(txt).hexdigest()
	sha512 = hashlib.sha512(txt).hexdigest()
	hashes = [md5,sha1,sha224,sha256,sha384,sha512]
	hnames = map(name_of, hashes)
	hashes = map(str.lower, hashes)
	if hash in hashes:
		i = hashes.index(hash)
		print "\n".join([
			"txt: %s [%d]"%(txt,len(txt)),
			"%s: %s [%d]"%(hnames[i],hashes[i],len(hashes[i]))
		])
		return True
	return False

if __name__ == "__main__":
	def h(hash):
		#binascii.hexlify(base64.b64decode(hash))
		return base64.b64decode(hash).encode("hex")
	hash1 = h("raLu6+eAmFelf2/uSy/67iTq57E=")
	hash2 = h("a791KNndKVmnr7N4mEJfZ1VfZ/Z3mHyufoYhCiyKDb38JI7C17JAEPRAutwiI7S1")
	hash3 = h("uAgUxeDzhrBjcWP9iv6pKQ==")
	hash4 = h("l5HL4K6RmgMwmUota6Jrjww6HaFcc7zl/KOUlYgabJA=")
	for i, hash in enumerate([hash1, hash2, hash3, hash4]):
		print>>sys.stderr, "#%d:"%(i+1), hash

	### Hash 1 ###
	charset, maxlen = [0,1,7,9], 16
	def h1_rand(charset, maxlen):
		return "".join(["%d"%random.choice([charset]) \
			for i in xrange(maxlen)])
	def h1_iter(w, charset, maxlen, hash):
		if len(w) == maxlen:
			return hmatch(hash, w)
		for c in charset:
			if h1_iter(w+str(c), charset, maxlen, hash):
				break
	h1_iter("", charset, maxlen, hash1)
	txt = h1_rand(charset, maxlen)
	while not hmatch(txt, hash1):
		txt = h1_rand(charset, maxlen)

	### Hash 3 ###
	intab, outtab = "aegiost", "4361057" #leetspeak
	leet = string.maketrans(intab, outtab)
	with open("file/lvl22-wordlist.txt") as f:
		words = map(string.strip, f.readlines())
	while True:
		word = list(random.choice(words))
		def cfind(s, ch):
			return [i for i,ltr in enumerate(s) if ltr==ch]
		possible = []
		for c in intab:
			possible.extend(cfind(word, c))
		if possible == []: continue
		idx = random.choice(possible)
		used = set()
		used.add(idx)
		word[idx] = word[idx].translate(leet)
		idx = random.randint(0, len(word)-1)
		while idx in used:
			idx = random.randint(0, len(word)-1)
		used.add(idx)
		word[idx] = word[idx].upper()
		punct = random.choice(string.punctuation)
		digit = random.choice(string.digits)
		txt = "".join(word)+punct+digit
		if hmatch(txt, hash3): sys.exit()

Did you beat the Swordmaster in Monkey Island? Even if, it ain't gonna help you this time. Get to know the mighty Nerd Master!

Connect to hackyeaster.hacking-lab.com:1400, and start the battle.

Here's an insult to start with: Go 127.0.0.1 to your mummy.

#!/usr/bin/env python
#-*- coding: utf-8 -*-

import os #os.linesep
import sys
import codecs
import json
import telnetlib
import hashlib
from random import randint

def find_answer(question, data):
	for entry in data:
		if entry["question"] == question:
			return entry["answer"].encode("utf-8")
	data.append({"question": question, "answer": ""})
	return ""

def ask_question(data):
	for entry in data:
		if entry["answer"] == "":
			return entry["question"].encode("utf-8")
	return data[randint(0,len(data)-1)]["question"].encode("utf-8")

def add_answer(question, answer, data):
	for entry in data:
		if entry["question"] == question:
			entry["answer"] = answer
			return

def show(data):
	for entry in data:
		print>>sys.stderr, u"Q: %s; A: %s" \
		%(entry["question"], entry["answer"])

if __name__ == "__main__":
	filepath = u"challenge23.json"
	with open(filepath) as file:
		data = json.load(file)
	host, port = "hackyeaster.hacking-lab.com", 1400
	nr = "\r\n"
	tn = telnetlib.Telnet(host, port)
	tn.read_until("Do you feel brave enough to challenge the mighty nerdmaster? (y|n)")
	tn.write("y" + nr)
	tn.read_until("---- YOUR TURN ----\n")
	while True:
		try:
			my_question = ask_question(data)
			tn.write(my_question + nr)
			print "I ask: " + my_question
			answer = tn.read_until("---- MY TURN ----\n").split("\n")[0]
			print "It Answered: " + answer
			if answer != "We've had this one before.":
				add_answer(my_question, answer, data)
			print
			print "---- MY TURN ----"
			print
			question = tn.read_until("\n").split("\n")
			print "It asked: " + question[0]
			my_answer = find_answer(question[0], data)
			tn.write(my_answer + nr)
			print "I answer: " + my_answer
			response = tn.read_until("---- YOUR TURN ----\n")
			print "resp:", response
		except EOFError as e:
			print ">> Connection closed"
			break
	with open(filepath, "w") as outfile:
		json.dump(data, outfile)
		print "%s updated"%filepath
	BUF_SIZE = 65536  #64KB chunk
	sha1 = hashlib.sha1()
	with open(filepath, "rb") as f:
		while True:
			data = f.read(BUF_SIZE)
			if not data: break
			sha1.update(data)
	print "sha1sum({}): {}".format(filepath, sha1.hexdigest())

• Q&A

question: "Go 127.0.0.1 to your mummy."
answer: "Won't work. I only support IPv6."

question: "Pna lbh ernq guvf?"
answer: "EBG13 vf sbe ynzref."

question: "Tell me your name, hobo. I need to check your records."
answer: "My name is bob'; DROP TABLE VALJ;--"

question: "You'll be 0xdeadbeef soon."
answer: "Not as long as I have my 0xcafebabe."

question: "After loosing to me, your life won't be the same anymore."
answer: "A Life? Cool! Where can I download one of those?"

question: "You must be jealous when seeing my phone's display."
answer: "Not really - Your pixels are so big, some of them have their own region code!"

question: "You're so slow, you must have been written in BASIC."
answer: "At least I don't have memory leaks like you."

question: "Ping! Anybody there?"
answer: "ICMP type 3, code 13: Communication Administratively Prohibited"

question: "This fight is like a hash function - it works in one direction only."
answer: "Too bad you picked LM hashing."

question: "You should leave your cave and socialize a bit."
answer: "I'm not anti-social. I'm just not user friendly."

question: "1f u c4n r34d th1s u r s70p1d."
answer: "You better check your spelling. Stoopid has two 'o's."

question: "I have more friends than you."
answer: "Yeah, but only until you update your Facebook profile with a real picture of you!"

question: "Af7ter th1s f1gh7, I w1ll pwn ur b0x3n."
answer: "Check your settings - you seem to have chosen the Klingon keyboard layout."

question: "format C:"
answer: "Specified drive does not exist."

question: "I bet you don't even understand binary."
answer: "Sure I do. Me and you, we are 10 different kind of persons."

question: "I'll check you out - any last words?"
answer: "svn:ignore"

Respect! you've beaten the mighty nerd master! Here's your egg:
http://hackyeaster.hacking-lab.com/hackyeaster/images/egg_23_j7vzfUzftszdf754fXDS.png

Crypto Chiefs Ltd. developed a new hash function, which takes a 'divide and conquer' approach and combines several well-known hash functions ("Split, Hash, And Merge"). The inventors claim that with this approach, their function becomes more secure. Can you prove they are wrong?

Create a string which produces the following hash:
	757c479895d6845b2b0530cd9a2b11

spec: shamhash.pdf

#!/usr/bin/env python
#-*- coding: utf-8 -*-

import sys
import codecs
import itertools
import hashlib
from hashlib import sha1, sha256, sha512
from Crypto.Hash import MD2, MD5

if __name__ == "__main__":
	ans = "afpmqtaaqidtaww8ntangecaaf9pt3"
	charset = "abcdefghijklmnopqrstuvwxyz0123456789"
	begin, end = 0, 6
	hashes = [(MD2, "757c47"), (MD5, "9895d6"), (sha1, "845b2b"), (sha256, "0530cd"), (sha512, "9a2b11")]
	for algo, frag in hashes:
		if algo in [MD2, MD5]:
			begin += 6
			end += 6
			continue
		print>>sys.stderr, algo.__name__
		for i in itertools.product(charset, repeat=6):
			word = "".join(i)
			try: whash = algo.new(word).hexdigest()
			except AttributeError:
				m = algo()
				m.update(word)
				whash = m.hexdigest()
			if frag == whash[begin:end]:
				print word, whash
				ans += word
				break
		begin += 6
		end += 6
	print "ans:", ans

• enter ans → redirect to http://hackyeaster.hacking-lab.com/hackyeaster/sham_m7f3ngUfg6LLzf530zub.html

jadandida.zip

• JAD: ref. JAva Decompiler
• IDA: ref. Interactive DisAssembler
• lib/libhe2015_Lizzle.dll::LizzleDLL::{Fizzle,Shizzle} loaded & used
• +2 other pure Java functions: {bizzle,rizzle}
• main method
  1. takes an input `key`, k
  2. then subsequently runs a total of 10 rounds × k = fizzle(rizzle(shizzle(bizzle(k))))
  3. s3cr3t.bin (assumes this is/contains egg w/ QR code) successfully decrypt()-ed if result "v3O] pmWm<Y(0=21".equals(k)
• use JD-GUI to decompile Java .class files → .java source code
• use IDA Pro v6.6 to generate C code from DLL, to analyse behaviour of imported native functions
• after careful analysis, and also by trying several "test"/"dummy" input values,
  • String bizzle(String s) case-sensitively increments char w/ wrap-around, ie. tr "a-yzA-YZ" "b-zaB-ZA"
  • String rizzle(String s) swaps case of all letters in s, ie. tr "[:upper:][:lower:]" "[:lower:][:upper:]"
  • size_t Shizzle(char *a1, char *a2) reverses a1 → a2, iff #a1 == 16 chars
  • size_t Fizzle(char *a1, char *a2) performs char transformation in printable ASCII range on a1, then swaps halves of result, producing a2

/*Java*/
String bizzle(String s)
{
	char[] chars = s.toCharArray();
	for(int i = 0; i < chars.length; i++)
	{
		char c = chars[i];
		if((c >= 'a') && (c < 'z'))
		{
			c = (char)(c + '\001');
		}
		else if(c == 'z')
		{
			c = 'a';
		}
		else if((c >= 'A') && (c < 'Z'))
		{
			c = (char)(c + '\001');
		}
		else if(c == 'Z')
		{
			c = 'A';
		}
		chars[i] = c;
	}
	return new String(chars);
}
String rizzle(String s)
{
	char[] chars = s.toCharArray();
	for(int i = 0; i < chars.length; i++)
	{
		char c = chars[i];
		if(Character.isUpperCase(c))
		{
			chars[i] = Character.toLowerCase(c);
		}
		else if(Character.isLowerCase(c))
		{
			chars[i] = Character.toUpperCase(c);
		}
	}
	return new String(chars);
}

/*DLL*/
size_t Fizzle(char *a1, char *a2)
{
	size_t result; // eax@1
	int v3; // ecx@3
	int v4; // eax@5
	int v5; // edx@8
	int v6; // edx@8
	char v7; // al@10
	char v8; // dl@10
	char v9; // al@10
	char v10; // dl@10
	char v11; // al@10
	char v12; // dl@10
	char v13; // al@10
	char v14; // dl@10
	char v15; // al@10
	char v16; // dl@10
	char v17; // al@10
	char v18; // dl@10
	char v19; // al@10
	char v20; // dl@10
	result = strlen(a1);
	if ( result == 16 )
	{
		v3 = 0;
		do
		{
			while ( 1 )
			{
				v4 = a1[v3];
				if ( (int)(v4 - 32) > 'Z' )
					break;
				a2[v3] = (v4 + v3 * v3 - 27) % 91 + 32;
				++v3;
				if ( v3 == 16 )
					goto LABEL_7;
			}
			a2[v3++] = v4;
		}
		while ( v3 != 16 );
LABEL_7:
		if ( a2 & 3 )
		{
			v7 = a2[8];
			a2[8] = a2;
			v8 = a2[1];
			a2 = v7;
			v9 = a2[9];
			a2[9] = v8;
			v10 = a2[2];
			a2[1] = v9;
			v11 = a2[10];
			a2[10] = v10;
			v12 = a2[3];
			a2[2] = v11;
			v13 = a2[11];
			a2[11] = v12;
			v14 = a2[4];
			a2[3] = v13;
			v15 = a2[12];
			a2[12] = v14;
			v16 = a2[5];
			a2[4] = v15;
			v17 = a2[13];
			a2[13] = v16;
			v18 = a2[6];
			a2[5] = v17;
			v19 = a2[14];
			a2[14] = v18;
			v20 = a2[7];
			a2[6] = v19;
			result = a2[15];
			a2[15] = v20;
			a2[7] = result;
		}
		else
		{
			v5 = a2[8];
			a2[8] = a2;
			result = a2[4];
			a2 = v5;
			v6 = a2[12];
			a2[12] = result;
			a2[4] = v6;
		}
		a2[16] = 0;
	}
	else
	{
		a2 = 0;
	}
	return result;
}
size_t Shizzle(char *a1, char *a2)
{
	size_t result;
	result = strlen(a1);
	if ( result == 16 )
	{
		a2[15] = *a1;
		a2[14] = a1[1];
		a2[13] = a1[2];
		a2[12] = a1[3];
		a2[11] = a1[4];
		a2[10] = a1[5];
		a2[9] = a1[6];
		a2[8] = a1[7];
		a2[7] = a1[8];
		a2[6] = a1[9];
		a2[5] = a1[10];
		a2[4] = a1[11];
		a2[3] = a1[12];
		a2[2] = a1[13];
		a2[1] = a1[14];
		result = a1[15];
		a2[16] = 0;
		a2 = result;
	}
	else
	{
		a2 = 0;
	}
	return result;
}

• Python code to undo effects of these functions (called in reverse order to invocation of their original counterparts)

#!/usr/bin/env python
#-*- coding: utf-8 -*-

import sys
import codecs
import string

sys.stdout = codecs.getwriter("utf8")(sys.stdout)
sys.stderr = codecs.getwriter("utf8")(sys.stderr)

def unfizzle_undo(c, idx):
	c = ord(c)
	c -= 32
	n = 0
	while True:
		cc = c + n * 91 + (27 - (idx * idx))
		if 32 <= cc <= 122: break
		n += 1
	c = cc
	c = chr(c)
	return c
def unfizzle(s):
	ss = list(s)
	ss[:8], ss[8:] = ss[8:], ss[:8]
	for i in xrange(15,-1,-1):
		ch = ss[i]
		if ord(ch) > ord("z"): continue
		else: ss[i] = unfizzle_undo(ch, i)
	return "".join(ss)
def unrizzle(s):
	ret = []
	for c in s:
		if c in string.ascii_letters:
			if c.isupper(): ret.append(c.lower())
			elif c.islower(): ret.append(c.upper())
		else: ret.append(c)
	return "".join(ret)
def unshizzle(s): return s[::-1]
def unbizzle(s):
	ret = []
	for c in s:
		added = False
		for lst in [string.ascii_lowercase, string.ascii_uppercase]:
			if c in lst:
				ret.append(lst[(lst.index(c)-1+len(lst))%len(lst)])
				added = True
				break
		if not added: ret.append(c)
	return "".join(ret)

if __name__ == "__main__":
	k = "v3O] pmWm<Y(0=21"
	for i in xrange(10):
		k = unbizzle(unshizzle(unrizzle(unfizzle(k))))
	print k

• provide key: jadnIdal0vecod3n to original JadAndIda.class, which decrypts s3cr3t.bin → eggizzle_25.png

Welcome to Clumsy Cloud™!
If your files are the eggs, then we are the hen™.

We encrypt all your files, with a strong passphrase. The passphrase is kept securely in this app, protected by a PIN.

• looking up lvl-specific param eg. "ovaederecumsale" or "8QeNdEdkspV6+1I77SEEEF4aWs5dl/auahJ46MMufkg="; or even "egg_26.png" reveals relevant code block
• @ /src/src/ps/hacking/hackyeaster/android/Activity.java:

…
private int a(String s, Context context)
{
	try
	{
		SecretKeySpec secretkeyspec = new SecretKeySpec(a(s, "ovaederecumsale", 10000), "AES");
		Cipher cipher = Cipher.getInstance("AES");
		cipher.init(2, secretkeyspec);
		String s1 = new String(cipher.doFinal(Base64.decode("8QeNdEdkspV6+1I77SEEEF4aWs5dl/auahJ46MMufkg=", 0)));

		DownloadManager downloadmanager = (DownloadManager)getSystemService("download");
		android.app.DownloadManager.Request request = new android.app.DownloadManager.Request(Uri.parse((new StringBuilder("http://hackyeaster.hacking-lab.com/hackyeaster/pin?p=")).append(s1).toString()));
		request.setTitle("Hacky Easter");
		request.setDescription("Egg Download");
		request.setDestinationInExternalPublicDir(Environment.DIRECTORY_DOWNLOADS, "egg_26.png");
		registerReceiver(new d(this), new IntentFilter("android.intent.action.DOWNLOAD_COMPLETE"));
		downloadmanager.enqueue(request);
		Toast.makeText(context, "Download started", 0).show();
	}
	catch (Exception exception)
	{
		return 1;
	}
	return 0;
}
…
public static byte[] a(String s, String s1, int i1)
{
	MessageDigest messagedigest = MessageDigest.getInstance("SHA1");
	byte abyte0[] = (new StringBuilder(String.valueOf(s1))).append(s).toString().getBytes();
	int j1 = 0;
	do
	{
		if (j1 >= i1)
		{
			byte abyte1[] = new byte[16];
			System.arraycopy(abyte0, 0, abyte1, 0, 15);
			return abyte1;
		}
		abyte0 = messagedigest.digest(abyte0);
		j1++;
	} while (true);
}
…

• public static byte[] a(String s, String s1, int i1) == hashing routine;
• while private int a(String s, Context context) performs decryption, due to 2 in cipher.init(2, secretkeyspec), using supplied PIN
• reusing these 2 routines highlighted in red; except swapping Android for Java8 Base64 decoding:

import java.util.Base64;
…
	Base64.Decoder decoder = Base64.getDecoder();
	byte[] dec64 = decoder.decode("8QeNdEdkspV6+1I77SEEEF4aWs5dl/auahJ46MMufkg=");
	String s1 = new String(cipher.doFinal(dec64));
…

• then exhaustively enum all 4-digit PIN combo, looking out for any ASCII-readable txt

import java.util.Base64;
…
	for(int i=0; i<9999; i++)
	{
		String PIN = String.format("%04d", i);
		String ciphertxt = crypt(PIN);
		if (ciphertxt != null
		&& ciphertxt.matches("^\\p{ASCII}*$"))
		{
			System.out.println(PIN+": "+ciphertxt);
			break;
		}
	}
…

• finds PIN=7113, linked to passwd=wirestarter54321
• @ http://hackyeaster.hacking-lab.com/hackyeaster/pin?p=wirestarter54321

You intercepted messages exchanged by evil Dr. Hopper and his agents. They used a One Time Pad for achieving perfect secrecy. Lucky for you, they have miserably failed, since the same key was used multiple times

Check out the ciphertexts, and try to decrypt them

Hint: The plaintexts consist of lowercase letters and spaces only

60c46964f83879618e2878de539f6f4a6271d716
63c37a6ca177792092602cc553c9684b
68d82c6bf4767f79dd617f9642d768057f63c1
6c8a7b6ce06a3161dd6a60d755d42d4d6d67
71c26929e96931698e2865d816d3624b687cd6
6cda6d6df87764709c6c7bd357d361556d77

• employ atk technique known as "crib drag"
  • define:crib - known/guessed piece of plaintext
  • Outline
  1. Guess a word that might appear in 1 of the ciphertext, eg. "the "
  2. Encode (word from step 1) as hex string
  3. XOR 2 ciphertexts
  4. XOR (hex string from step 2) @ each pos of (XOR(2 cipher-texts (from step 3)))
  5. 5a. When result from step 4 == readable English text, guess the English word and expand crib search
  6. 5b. Otherwise, try XOR of crib word @ nxt pos
• 
• key: 05aa0c0981181100fd080cb636bf0d250c13b878
• plaintext

enemy has the bonbon
five oh oh seven
mr bunny is the spy
i wear a black hat
the hq is in london
ipadyoupadweallpad