Hi All,

There are four solutions to fix this issue:

1) Carry a copy of mask_password() method to keystoneauth from oslo_utils [1]:
Pros:
A. keystoneauth will use already tested and used version of mask_password.
	
Cons:
A. keystoneauth will have to keep the version of mask_password() method sync with
   oslo_utils version. If there are any new "_SANITIZE_KEYS" added to oslo_utils
   mask_password then those should be added in keystoneauth mask_password also.
B. Copying the "mask_password" will also require to copy its supporting code [2]
   which is huge.



2) Use Oslo.utils mask_password() method in keystoneauth:
Pros:
A) No synching issue as described in solution #1. keystoneauth will directly use
   mask_password() method from Oslo.utils.
	
Cons:
A) You will need oslo.utils library to use keystoneauth.
Objection by community:
- keystoneauth community don't want any dependency on any of OpenStack common oslo
  libraries.
Please refer to the comment from Morgan:
https://bugs.launchpad.net/keystoneauth/+bug/1700751/comments/3



3] Add a custom logging filter in oslo logger
Please refer to POC sample here: http://paste.openstack.org/show/617093/

OpenStack core services using any OpenStack individual python-*client (for e.g
python-cinderclient used in nova service) will need to pass oslo_logger object
during its initialization which will do the work of masking sensitive information. 

Note: In nova, oslo.logger object is not passed during cinderclient initialization (https://github.com/openstack/nova/blob/master/nova/volume/cinder.py#L135-L141),
In this case, sensitive information will not be masked as it isn’t using Oslo.logger.
	
Pros:
A) No changes required in oslo.logger or any OpenStack services if mask_password
   method is modified in oslo.utils.
	
Cons:
A) Every log message will be scanned for certain password fields degrading the performance.
B) If consumer of keystoneauth doesn’t use oslo_logger, then the sensitive information
   will not be masked.
C) Will need to make changes wherever applicable to the OpenStack core services to pass
   oslo.logger object during python-novaclient initialization.



4] Add mask_password formatter parameter in oslo_log:
Add "mask_password" formatter to sanitize sensitive data and pass it as a keyword argument
to the log statement. If the mask_password is set, then only the sensitive information
will be masked at the time of logging.

The log statement will look like below: 

logger.debug("'adminPass': 'Now you see me'"), mask_password=True)

Please refer to the POC code here: http://paste.openstack.org/show/618019/
	
Pros:	
A) No changes required in oslo.logger or any OpenStack services if mask_password method is
modified in oslo.utils.

Cons:
A) If consumer of keystoneauth doesn’t use oslo_logger, then the sensitive information
will not be masked.
B) If you forget to pass mask_password=True for logging messages where sensitive information
is present, then those fields won't be masked with ***. But this can be clearly documented
as suggested by Morgan and Lance.
C) This solution requires you to add a below check in keystoneauth to avoid from an
exception being raised in case logger is pure python Logger as it doesn’t accept
mask_password keyword argument.

if isinstance(logger, logging.Logger):
    logger.debug(' '.join(string_parts))
else:
    logger.debug(' '.join(string_parts), mask_password=True)
		
This check assumes that the logger instance will be oslo_log only if it is not of python
default logging.Logger. Keystoneauth community is not ready to have any dependency on
any oslo-* lib, so it seems this solution has low acceptance chances.

Please let me know your opinions about the above four approaches. Which one should we adopt?

[1] https://github.com/openstack/oslo.utils/blob/master/oslo_utils/strutils.py#L248-L313
[2] https://github.com/openstack/oslo.utils/blob/6e04f882c4308ff64fa199d1b127ad225e0a30c4/oslo_utils/strutils.py#L56-L96