'Decrypting an encrypted text by the use of a private key.
:param enctext: The encrypted text as a string
:return: The decrypted text'

def decrypt(self, enctext, key_file=None, passphrase=None):

    if ((key_file is None) or (len(key_file.strip()) == 0)):
        key_file = self.key_file
    if (passphrase is None):
        passphrase = self.key_file_passphrase
    return self.crypto.decrypt(enctext, key_file, passphrase)
