import os
os.environ['PWNLIB_NOTERM'] = 'True'
os.environ['PWNLIB_SILENT'] = 'True'

if __name__ == '__main__':
    #server = remote(HOST, PORT)
    #server.send(iv)
    #server.send(ciphertext)
    #response = server.recv(1024)
    #print(response)
    #server.close()

    #server = remote(HOST, PORT)
    #server.send(iv)

    #edt = bytearray(ciphertext)
    #edt[-1] = 0
    #server.send(edt)
    #response = server.recv(1024)
    #print(response)
    #server.close()
#---------------
    print(len(ciphertext)//AES.block_size)
    N = len(ciphertext)//AES.block_size)
    #This initial part will be non modifiabke
    #We put all the block except the last one 
    initial_part = ciphertext[:(N-2)*AES.block_size]
    #The second to last block is the one swapped in CBC then it is not dependent from the others(?)
    block_to_modify =  bytearray(ciphertext[(N-2)*AES.block_size:(N-1)*AES.block_size])
    last_block = ciphertext[(N-1]*AES.block_size:]

    byte_index = AES.block_size - 1
    c15 = block_to_modify[byte_index]

    for c_prime_15 in range(256):

        block_to_modify[byte_index] = c_prime_15
        to_send = initial_part + block_to_modify + last_block

        server = remote(HOST, PORT)
        server.send(iv)
        server.send(to_send)
        response = server.recv(1024)
        #print(response)
        server.close()
   
        if response = b'OK':
            print("c_prime_15"+str(c_prime_15))
            p_prime_15 = c_prime_15 ^ 1
            p_15 = p_prime_15 ^ c_15
            print("p_prime_15"+str(p_prime_15))  
            print("p_15"+str(p_15))
    p_prime_15 = 191
    
    c_second_15 = p_prime_15 ^ 2
    block_to_modify[byte_index] = c_second_15

    byte_index -= 1
    c_14 = block_to_modify[byte_index]
    
    for c_prime_14 in range(256):
        
        block_to_modify[byte_index] = c_prime_14
        to_send = initial_part + block_to_modify + last_block

        ##connect to the server etc