@@ -0,0 +1,439 @@
+def pad_with_pkcs7(message: bytes, block_length: int) -%3E bytes:%0A    if len(message) %3E= block_length:%0A        amount_to_pad = len(message) %25 block_length%0A    else:%0A        amount_to_pad = block_length - len(message)%0A    res = message + (bytes(%5Bamount_to_pad%5D) * amount_to_pad)%0A    return res%0A%0A%0Aprint('Set 2')%0Aprint('Challenge 9')%0Ares9 = pad_with_pkcs7(b'YELLOW SUBMARINE', 20)%0Aassert res9 == b'YELLOW SUBMARINE%5Cx04%5Cx04%5Cx04%5Cx04'%0Aprint(res9)%0A

Solve Challenge 9