02-redundant-rsa.py

#!/usr/bin/env python3
# -*- coding: UTF-8 -*-

def main():
    assert 21846 * 3 - 65537 == 1
    n = 8208175638972200577186038102634114258848486365767463332763957381946985480397227219800325703361508208728778216773973313756762762324416016301819271949512427
    c3 = 510199524103978915755062119293765889950938959100085136114101960072728304594090942964306874023123457091885387418124063977610496306587745044542739034336862
    c65537 = 4673531855283872496727093452348048121242854682829577660566947295656149440028839210065857595110277181842297946378296819272562912619683355333762343087859186

    m = pow(c3, 21846, n) * pow(c65537, -1, n) % n
    flag = m.to_bytes((m.bit_length()+7)//8, 'big')
    print(flag)
    # kurenaifCTF{you_4re_redundant_master}

if __name__ == '__main__':
    main()