Add challenge

chals/crypto/hidden-runes/challenge.yml → chals/crypto/hidden_runes/challenge.yml

@@ -1,4 +1,4 @@
-name: "Hidden Runes"
+name: "XOR 101"
 author: Sophia
 category: Crypto
 description: |-

chals/crypto/hidden_runes/flag.txt

@@ -0,0 +1 @@
+sigpwny{alphabets_are_very_fun}

chals/crypto/password_cracking/flag.txt

@@ -0,0 +1 @@
+sigpwny{code_br3aker_!}

chals/crypto/xor_101/chal.py

@@ -0,0 +1,14 @@
+def encrypt(message, key):
+    return bytes([b ^ key[i % len(key)] for i, b in enumerate(message)])
+
+def main():
+    passphrase = input("Enter passphrase: ")
+    key = [ord(char) for char in passphrase]
+    message = b"sigpwny{fake_flag}"
+
+    # Encrypt
+    ciphertext = encrypt(message, key)
+    print("Encrypted message:", ciphertext.hex())
+
+if __name__ == '__main__':
+    main()

chals/crypto/xor_101/challenge.yml

@@ -0,0 +1,26 @@
+name: "XOR 101"
+author: Sophia
+category: Crypto
+description: |-
+  Breaking news: Seals have reached a new level of intelligence and can now create their own XOR challenges.
+  One left a comment on a photo of themself. Can you use that to discover the flag?
+
+  **author**: Sophia
+value: 150
+type: dynamic
+tags:
+  - easy
+extra:
+  initial: 150
+  decay: 125
+  minimum: 100
+flags:
+  - sigpwny{seals_like_x0r}
+files:
+  - message.txt
+  - chal.py
+  - seal1.png
+hints:
+  - Can you use information from the seal photo to decrypt the message?
+  - Exiftool is helpful.
+state: hidden

chals/crypto/xor_101/flag.txt

@@ -0,0 +1 @@
+sigpwny{seals_like_x0r}

chals/crypto/xor_101/message.txt

@@ -0,0 +1 @@
+07060a110301100806030601001a13301e15151d1d160539052a11440612

chals/crypto/xor_101/sol.py

@@ -0,0 +1,18 @@
+# Step 1: Inspect "comment" tag in metadata for passphrase (ex: exiftool seal1.png)
+passphrase = "tomatoisafruit"
+
+# Step 2:
+def decrypt(ciphertext, key):
+    return bytes([b ^ key[i % len(key)] for i, b in enumerate(ciphertext)])
+
+# Provided from message.txt
+input = "07060a110301100806030601001a13301e15151d1d160539052a11440612"
+
+# Convert hexadecimal string to bytes
+b_input = bytes.fromhex(input)
+
+# Use key to decrypt
+key = [ord(char) for char in passphrase]
+output = decrypt(b_input, key)
+
+print("Flag:", output.decode('utf-8'))