wechall challenges

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Training: Get Sourced

check the source, end of html element

Training: Stegano I

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❯ wget https://www.wechall.net/challenge/training/stegano1/stegano1.bmp
❯ file stegano1.bmp
stegano1.bmp: PC bitmap, Windows 3.x format, 4 x 4 x 24, image size 48, cbSize 102, bits offset 54

❯ xxd stegano1.bmp
00000000: 424d 6600 0000 0000 0000 3600 0000 2800  BMf.......6...(.
00000010: 0000 0400 0000 0400 0000 0100 1800 0000  ................
00000020: 0000 3000 0000 0000 0000 0000 0000 0000  ..0.............
00000030: 0000 0000 0000 4c6f 6f6b 2077 6861 7420  ......Look what
00000040: 7468 6520 6865 782d 6564 6974 2072 6576  the hex-edit rev
00000050: 6561 6c65 643a 2070 6173 7377 643a 7374  ealed: passwd:st
00000060: 6567 616e 6f49                           ****** <-just hidden

Training: ASCII

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# use cyberchef to decode, from decimal
input:
84, 104, 101, 32, 115, 111, 108, 117, 116, 105, 111, 110, 32, 105, 115, 58, 32, 111, 114, 100, 97, 101, 110, 112, 114, 115, 115, 105, 112
The solution is: ************

Crypto - Caesar I

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XLI UYMGO FVSAR JSB NYQTW SZIV XLI PEDC HSK SJ GEIWEV ERH CSYV YRMUYI WSPYXMSR MW RTIKVVRIMJPT

use cyberchef to decode, don't pick the Caesar Box Cipher(Transposition), pick the ROT13(Substitution) and change amount

THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG OF CAESAR AND YOUR UNIQUE SOLUTION IS ************

Encodings - URL encode

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Your task is to decode the following:

%59%69%70%70%65%68%21%20%59%6F%75%72%20%55%52%4C%20%69%73%20%63%68%61%6C%6C%65%6E%67%65%2F%74%72%61%69%6E%69%6E%67%2F%65%6E%63%6F%64%69%6E%67%73%2F%75%72%6C%2F%73%61%77%5F%6C%6F%74%69%6F%6E%2E%70%68%70%3F%70%3D%70%68%67%6F%66%63%72%62%6F%69%73%62%26%63%69%64%3D%35%32%23%70%61%73%73%77%6F%72%64%3D%66%69%62%72%65%5F%6F%70%74%69%63%73%20%56%65%72%79%20%77%65%6C%6C%20%64%6F%6E%65%21

cyberchef with url decode

Yippeh! Your URL is challenge/training/encodings/url/saw_lotion.php?p=phgofcrboisb&cid=52#password=fibre_optics Very well done!

concat the url with https://www.wechall.net/ <-

WWW-Robots

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https://www.wechall.net/robots.txt

User-agent: *
Disallow: /challenge/training/www/robots/T0PS3CR3T
...

concat url

https://www.wechall.net/challenge/training/www/robots/T0PS3CR3T

btw, if you use vim, press gx to open the link

Prime Factory

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def is_prime(n): return n > 1 and all(n % i != 0 for i in range(2, int(n**0.5) + 1))

if __name__ == "__main__":
    p = 1000000
    found = []
    while len(found) < 2:
        p += 1
        if is_prime(p) and is_prime(sum(int(d) for d in str(p))):
            found.append(p)
    print(f'{found[0]}{found[1]}')

MySQL Authentication Bypass - The classic