$ nc verifier-01.play.midnightsunctf.se 31337

    Hello! Welcome to the message signature service.
    Here you can get messages signed and signatures verified.
    We even have a bug bounty program to prove how secure we are.
    

    1. Sign message
    2. Verify signature
    3. Get flag
    4. Exit
    
> 1

    Please input a message that you want to be signed.
    
message> please_give_me_the_flag
Signature: f59f260940c9c13d255c81a08769e314ac399d26678bf700ee4620406b254fc95b949d264508d139721ebd749b52ce09

    1. Sign message
    2. Verify signature
    3. Get flag
    4. Exit
    
> 3

    Welcome to the bug bounty program for this service.
    No one will ever be able to forge a valid signature.
    To prove this, if you can manage to provide a valid signature for the message "please_give_me_the_flag" I will give you a treat.
    
signature> f59f260940c9c13d255c81a08769e314ac399d26678bf700ee4620406b254fc95b949d264508d139721ebd749b52ce09
Signature valid: midnight{number_used_once_or_twice_or_more}


Note: challenge was clearly broken - therefore "verifier2" added