Added challenge 239

239/convertme.py

@@ -0,0 +1,35 @@
+
+import random
+
+
+
+def str_xor(secret, key):
+    #extend key to secret length
+    new_key = key
+    i = 0
+    while len(new_key) < len(secret):
+        new_key = new_key + key[i]
+        i = (i + 1) % len(key)        
+    return "".join([chr(ord(secret_c) ^ ord(new_key_c)) for (secret_c,new_key_c) in zip(secret,new_key)])
+
+
+flag_enc = chr(0x15) + chr(0x07) + chr(0x08) + chr(0x06) + chr(0x27) + chr(0x21) + chr(0x23) + chr(0x15) + chr(0x5f) + chr(0x05) + chr(0x08) + chr(0x2a) + chr(0x1c) + chr(0x5e) + chr(0x1e) + chr(0x1b) + chr(0x3b) + chr(0x17) + chr(0x51) + chr(0x5b) + chr(0x58) + chr(0x5c) + chr(0x3b) + chr(0x42) + chr(0x57) + chr(0x5c) + chr(0x0d) + chr(0x5f) + chr(0x06) + chr(0x46) + chr(0x5c) + chr(0x13)
+
+
+num = random.choice(range(10,101))
+
+print('If ' + str(num) + ' is in decimal base, what is it in binary base?')
+
+ans = input('Answer: ')
+
+try:
+  ans_num = int(ans, base=2)
+  
+  if ans_num == num:
+    flag = str_xor(flag_enc, 'enkidu')
+    print('That is correct! Here\'s your flag: ' + flag)
+  else:
+    print(str(ans_num) + ' and ' + str(num) + ' are not equal.')
+  
+except ValueError:
+  print('That isn\'t a binary number. Binary numbers contain only 1\'s and 0\'s')