'Decrypt the given data and return it
:arg b_data: A byte string containing the encrypted data
:arg b_password: A byte string containing the encryption password
:arg key_length: Length of the key
:returns: A byte string containing the decrypted data'

@classmethod
def decrypt(cls, b_vaulttext, secret, key_length=32):

    display.deprecated(u'The    VaultAES    format    is    insecure    and    has    been    deprecated    since    Ansible-1.5.        Use    vault    rekey    FILENAME    to    switch    to    the    newer    VaultAES256    format', version='2.3')
    b_vaultdata = unhexlify(b_vaulttext)
    b_salt = b_vaultdata[len('Salted__'):16]
    b_ciphertext = b_vaultdata[16:]
    b_password = secret.bytes
    if HAS_CRYPTOGRAPHY:
        b_plaintext = cls._decrypt_cryptography(b_salt, b_ciphertext, b_password, key_length)
    elif HAS_PYCRYPTO:
        b_plaintext = cls._decrypt_pycrypto(b_salt, b_ciphertext, b_password, key_length)
    else:
        raise AnsibleError((NEED_CRYPTO_LIBRARY + '    (Late    detection)'))
    return b_plaintext
