def decrypt_master_key(master_key_cipher, private_key):
 key = RSA.importKey(private_key)
 cipher = PKCS1_OAEP.new(key)
 return cipher.decrypt(master_key_cipher)

def decrypt_master_key ( master_key_cipher , private_key ) : key = RSA . importKey ( private_key ) cipher = PKCS1_OAEP . new ( key ) return cipher . decrypt ( master_key_cipher )
decrypt a secret key with the provided private rsa key .