root@kali:~/tools/CTF-RSA-tool# python solve.py --verbose -k examples/jarvis_oj_hardRSA/pubkey.pem --decrypt examples/jarvis_oj_hardRSA/flag.enc Traceback (most recent call last): File "solve.py", line 148, in <module> attackobj = lib.RSAutils.RSAAttack(args) File "/root/tools/CTF-RSA-tool/lib/RSAutils.py", line 34, in __init__ self.c = libnum.s2n(f.read().strip()) File "/usr/local/lib/python2.7/dist-packages/libnum/strings.py", line 10, in s2n return int(s.encode("utf-8").hex(), 16) UnicodeDecodeError: 'ascii' codec can't decode byte 0xde in position 1: ordinal not in range(128)