initial commit

CTF/W1seGuy/W1seGuy.py

@@ -0,0 +1,49 @@
+import random
+import socketserver 
+import socket, os
+import string
+
+flag = open('flag.txt','r').read().strip()
+
+def send_message(server, message):
+    enc = message.encode()
+    server.send(enc)
+
+def setup(server, key):
+    flag = 'THM{thisisafakeflag}' 
+    xored = ""
+
+    for i in range(0,len(flag)):
+        xored += chr(ord(flag[i]) ^ ord(key[i%len(key)]))
+
+    hex_encoded = xored.encode().hex()
+    return hex_encoded
+
+def start(server):
+    res = ''.join(random.choices(string.ascii_letters + string.digits, k=5))
+    key = str(res)
+    hex_encoded = setup(server, key)
+    send_message(server, "This XOR encoded text has flag 1: " + hex_encoded + "\n")
+    
+    send_message(server,"What is the encryption key? ")
+    key_answer = server.recv(4096).decode().strip()
+
+    try:
+        if key_answer == key:
+            send_message(server, "Congrats! That is the correct key! Here is flag 2: " + flag + "\n")
+            server.close()
+        else:
+            send_message(server, 'Close but no cigar' + "\n")
+            server.close()
+    except:
+        send_message(server, "Something went wrong. Please try again. :)\n")
+        server.close()
+
+class RequestHandler(socketserver.BaseRequestHandler):
+    def handle(self):
+        start(self.request)
+
+if __name__ == '__main__':
+    socketserver.ThreadingTCPServer.allow_reuse_address = True
+    server = socketserver.ThreadingTCPServer(('0.0.0.0', 1337), RequestHandler)
+    server.serve_forever()

CTF/W1seGuy/decrypt.py

@@ -0,0 +1,38 @@
+import itertools
+
+def xor_decrypt(hex_encoded, key):
+    data = bytes.fromhex(hex_encoded)
+    decrypted = ''
+    for i in range(len(data)):
+        decrypted += chr(data[i] ^ ord(key[i % len(key)]))
+    return decrypted
+
+def recover_xor_key(hex_encoded, known_start="THM{", known_end="}"):
+    data = bytes.fromhex(hex_encoded)
+
+    # Step 1: Recover partial key from known prefix
+    partial_key = [chr(data[i] ^ ord(known_start[i])) for i in range(len(known_start))]
+
+    # Step 2: Brute-force remaining characters of 5-character key
+    charset = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789'
+    key_length = 5
+    unknown_length = key_length - len(partial_key)
+
+    for combo in itertools.product(charset, repeat=unknown_length):
+        key = ''.join(partial_key + list(combo))
+        decrypted = xor_decrypt(hex_encoded, key)
+        if decrypted.startswith(known_start) and decrypted.endswith(known_end):
+            return key, decrypted
+
+    return None, None
+
+if __name__ == "__main__":
+    hex_encoded = "272f0549124206245c16361f3c731607532b590132093a01031f2b315a370113310217011f07401f"
+    key, message = recover_xor_key(hex_encoded)
+
+    if key:
+        print("✅ Found key:", key)
+        print("🔓 Decrypted message:", message)
+    else:
+        print("❌ Key not found.")
+