Source code for keystone.cmd.doctor.tokens

# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
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import keystone.conf


CONF = keystone.conf.CONF


def symptom_unreasonable_max_token_size():
    """`keystone.conf [DEFAULT] max_token_size` should be adjusted.

    This option is intended to protect keystone from unreasonably sized tokens,
    where "reasonable" is mostly dependent on the `keystone.conf [token]
    provider` that you're using. If you're using one of the following token
    providers, then you should set `keystone.conf [DEFAULT] max_token_size`
    accordingly:

    - For UUID, set `keystone.conf [DEFAULT] max_token_size = 32`, because UUID
      tokens are always exactly 32 characters.

    - For PKI and PKIZ, set `keystone.conf [DEFAULT] max_token_size = 8192`,
      because PKI and PKIZ tokens can be quite large, but any larger than 8192
      and they tend to break certain implementations of HTTP.

    - For Fernet, set `keystone.conf [DEFAULT] max_token_size = 255`, because
      Fernet tokens should never exceed this length in most deployments.
      However, if you are also using `keystone.conf [identity] driver = ldap`,
      Fernet tokens may not be built using an efficient packing method,
      depending on the IDs returned from LDAP, resulting in longer Fernet
      tokens (adjust your `max_token_size` accordingly).
    """
    return (
        'uuid' in CONF.token.provider and CONF.max_token_size != 32
        or 'pki' in CONF.token.provider and CONF.max_token_size < 8192
        or 'pkiz' in CONF.token.provider and CONF.max_token_size < 8192
        or 'fernet' in CONF.token.provider and CONF.max_token_size > 255)