* Add more Open Redirect test cases

* Add whitelisted domain to test

* Add more test cases

* Improve invalid redirect regex

* Changed how gitlab-group is parsed, from string to []string

See #637

* Point out that gitlab-group can be a list

See #637

* Reflect to the []string change on pkg/apis/options/options.go

See #637

* Move cfg option gitlab_group to gitlab_groups

See #637

* Renamed Group to Groups

See #637

* Reflect the change on gitlab.go as well

See #637

* Added #639

* Added the author of #639 to the CHANGELOG

* Add the gitlab_groups env change to CHANGELOG.md

See #639

Co-authored-by: Joel Speed <Joel.speed@hotmail.co.uk>

Co-authored-by: Joel Speed <Joel.speed@hotmail.co.uk>

helm kubernetes example based on kind cluster and nginx ingress

# Conflicts:
#	CHANGELOG.md

Verify main vs extra JWT bearers differently

# Conflicts:
#	CHANGELOG.md

When using the configured provider JWT Verifier, it makes
sense to use the provider `CreateSessionStateFromBearerToken`
method. For any extra JWT Issuers, they should use a generic
default verifier.

Don't log invalid redirect if redirect is empty

Add HealthCheck middleware

* expose kind to 443 port
* make helm optional
* rename folder to kubernetes

# Conflicts:
#	CHANGELOG.md

* Adding one more example - keycloak - alongside with dex IDP.

* don't expose keycloak and proxy ports to the host

* specify email-domain list option in documentation

* get rid of nginx and socat to simplify the example as per https://github.com/oauth2-proxy/oauth2-proxy/pull/604#issuecomment-640054390

* get rid of the scripts - use static file for keycloak startup

* changelog entry

* Update CHANGELOG.md

Co-authored-by: Joel Speed <Joel.speed@hotmail.co.uk>

Encryption efficiency improvements

This helper method is only applicable for Base64 wrapped
encryption since it operated on string -> string primarily.
It wouldn't be used for pure CFB/GCM ciphers. After a messagePack
session refactor, this method would further only be used for
legacy session compatibility - making its placement in cipher.go
not ideal.

Have it take in a cipher init function as an argument.
Remove the confusing `newCipher` method that matched legacy behavior
and returns a Base64Cipher(CFBCipher) -- instead explicitly ask for
that in the uses.

During the upcoming encoded session refactor, AES GCM is ideal
to use as the Redis (and other DB like stores) encryption wrapper
around the session because each session is encrypted with a
distinct secret that is passed by the session ticket.

All Encrypt/Decrypt Cipher implementations will now take
and return []byte to set up usage in future binary compatible
encoding schemes to fix issues with bloat encrypting to strings
(which requires base64ing adding 33% size)

Make signedValue & Validate operate on []byte
by default and not assume/cast string. Any casting
will be done from callers.

These will take in []byte and not automatically
Base64 encode/decode.