# findme
## Background
find the Coordinate ( be precise )
example : crew{19.3212,122.1235}
flag md5 : cbb510f471de8b8808890599e9893afa (example cmd: `echo -n "crew{19.3212,122.1235}" | md5sum`)
Author : st4rn
![](https://raw.githubusercontent.com/siunam321/CTF-Writeups/main/CrewCTF-2023/images/Pasted%20image%2020230710142735.png)
## Find the flag
**In this challenge, we can download a [file](https://github.com/siunam321/CTF-Writeups/blob/main/CrewCTF-2023/Misc/findme/chall.png):**```shell┌[siunam♥Mercury]-(~/ctf/CrewCTF-2023/Misc/findme)-[2023.07.08|16:58:47(HKT)]└> file chall.png  chall.png: PNG image data, 1920 x 963, 8-bit/color RGB, non-interlaced```
![](https://raw.githubusercontent.com/siunam321/CTF-Writeups/main/CrewCTF-2023/images/Pasted%20image%2020230708165900.png)
As you can see, **it's a road somewhere in Japan**. (As a Hongkonger, I can read traditional and simplify Chinese, as well as some kanji, so right off the bat I knew it's in Japan.)
During doing OSINT in finding a place, I always take a note of some characteristics of the picture:
1. Tall building on the top left2. 2 road signs, 1 is brown, 1 is blue3. It has an overpass, stair is on the right side4. It has a shelter map on the left side (避難場所)5. It has a mountain in the middle
Armed with the above information, we can start finding the abstract location of the picture.
**First, I wanna search where 甲斐 is:**
![](https://raw.githubusercontent.com/siunam321/CTF-Writeups/main/CrewCTF-2023/images/Pasted%20image%2020230708170910.png)
As you can see, there's mountains on the west side:
![](https://raw.githubusercontent.com/siunam321/CTF-Writeups/main/CrewCTF-2023/images/Pasted%20image%2020230708171018.png)
Therefore, the picture's location is somewhat near 甲斐.
**Then, I started looking for the tall building, and I found this:**
![](https://raw.githubusercontent.com/siunam321/CTF-Writeups/main/CrewCTF-2023/images/Pasted%20image%2020230708171509.png)
Which looks very similar to the picture's one.
**Then, I found the blue road sign:** 
![](https://raw.githubusercontent.com/siunam321/CTF-Writeups/main/CrewCTF-2023/images/Pasted%20image%2020230708171632.png)
![](https://raw.githubusercontent.com/siunam321/CTF-Writeups/main/CrewCTF-2023/images/Pasted%20image%2020230708171715.png)
Nice! We found the correct location!
**However, I couldn't find the exact coordinate, so I brute forced it lol:**```python#!/usr/bin/env python3from hashlib import md5
if __name__ == '__main__':    targetFlagMd5 = 'cbb510f471de8b8808890599e9893afa'    latitude = '35'    longitude = '138'    try:        for latitudeDecimal in range(6600, 10000):            for longitudeDecimal in range(5000, 10000):                coordinate = f'{latitude}.{latitudeDecimal:04d},{longitude}.{longitudeDecimal:04d}'                flag = 'crew{' + coordinate + '}'                hashed = md5(flag.encode('utf-8')).hexdigest()                 print(f'[*] Trying coordinate: {coordinate} ({flag}). Hashed: {hashed}', end='\r')                if hashed == targetFlagMd5:                    print(f'\n[+] Found correct coordinate: {coordinate}. Hashed: {hashed}')                    exit(0)    except KeyboardInterrupt:        print('\n[*] Bye!')```
```shell┌[siunam♥Mercury]-(~/ctf/CrewCTF-2023/Misc/findme)-[2023.07.08|17:36:10(HKT)]└> python3 solve.py[*] Trying coordinate: 35.6682,138.5699 (crew{35.6682,138.5699}). Hashed: cbb510f471de8b8808890599e9893afa[+] Found correct coordinate: 35.6682,138.5699. Hashed: cbb510f471de8b8808890599e9893afa```
- **Flag: `crew{35.6682,138.5699}`**
## Conclusion
What we've learned:
1. Finding Location Via OSINT