DOC Document using symfony/validator logic (#590)

en/02_Developer_Guides/09_Security/05_Secure_Coding.md

@@ -578,47 +578,60 @@ salt values generated with the strongest entropy generators available on the pla
 (see [RandomGenerator](api:SilverStripe\Security\RandomGenerator)). This prevents brute force attacks with
 [Rainbow tables](https://en.wikipedia.org/wiki/Rainbow_table).
 
-Strong passwords are a crucial part of any system security. So in addition to storing the password in a secure fashion,
-you can also enforce specific password policies by configuring a
-[PasswordValidator](api:SilverStripe\Security\PasswordValidator). This can be done through a `_config.php` file
-at runtime, or via YAML configuration.
+Strong passwords are a crucial part of any system security.
 
-The default password validation rules are configured in the framework's `passwords.yml`
-file. You will need to ensure that your config file is processed after it.
+The default password validator uses the [`PasswordStrength` constraint](https://symfony.com/doc/current/reference/constraints/PasswordStrength.html) in `symfony/validator`, which determines a password's strength based on its level of entropy.
+
+You can change the required strength of valid passwords by setting the [`EntropyPasswordValidator.password_strength`](api:SilverStripe\Security\Validation\EntropyPasswordValidator->password_strength) configuration property to one of the valid [minScore values](https://symfony.com/doc/current/reference/constraints/PasswordStrength.html#minscore):
+
+```yml
+SilverStripe\Security\Validation\EntropyPasswordValidator:
+  password_strength: 4
+```
+
+You can also enforce that passwords are not repeated by setting the [`PasswordValidator.historic_count`](api:SilverStripe\Security\Validation\PasswordValidator->historic_count) configuration property:
+
+```yml
+SilverStripe\Security\Validation\PasswordValidator:
+  historic_count: 6
+```
+
+The above example will check that the password wasn't used within the previous 6 passwords set for the member.
+
+### Rule-based password validation
+
+If you want more finegrained control over exactly how a "strong" password is determined, you can use the [`RulesPasswordValidator`](api:SilverStripe\Security\Validation\RulesPasswordValidator) which uses an array of regular expressions to validate a password. You can swap to using that validator and configure its options with YAML configuration:
 
 ```yml
 ---
 Name: mypasswords
 After: '#corepasswords'
 ---
 SilverStripe\Core\Injector\Injector:
-  SilverStripe\Security\PasswordValidator:
-    properties:
-      MinLength: 7
-      HistoricCount: 6
-      MinTestScore: 3
+  SilverStripe\Security\Validation\PasswordValidator:
+    class: 'SilverStripe\Security\Validation\RulesPasswordValidator'
 
-# In the case someone uses `new PasswordValidator` instead of Injector, provide some safe defaults through config.
-SilverStripe\Security\PasswordValidator:
+SilverStripe\Security\Validation\RulesPasswordValidator:
   min_length: 7
-  historic_count: 6
   min_test_score: 3
 ```
 
-### Configuring custom password validator tests
+> [!NOTE]
+> The [`PasswordValidator.historic_count`](api:SilverStripe\Security\Validation\PasswordValidator->historic_count) configuration property also applies to the `RulesPasswordValidator`.
 
-The default password validation character strength tests can be seen in the `PasswordValidator.character_strength_tests`
-configuration property. You can add your own with YAML config, by providing a name for it and a regex pattern to match:
+You can also add additional regular expression tests to the validator:
 
 ```yml
-SilverStripe\Security\PasswordValidator:
+SilverStripe\Security\Validation\RulesPasswordValidator:
   character_strength_tests:
-    contains_secret_word: '/1337pw/'
+    at-least-three-special-chars: '/[\(\)\&\^\%\$\#\@\!]{3,}/'
 ```
 
-This will ensure that a password contains `1337pw` somewhere in the string before validation will succeed.
+The above example requires at least 3 of the characters `()&^%$#@!` to be included in the password.
+
+Note that the [`RulesPasswordValidator.min_test_score`](api:SilverStripe\Security\Validation\RulesPasswordValidator->min_test_score) configuration property determines how many of the regular expression tests must pass for a password to be valid. If the test score is lower than the number of tests you have, the password *doesn't* have to match all of them to be valid.
 
-### Other options
+### More password security options
 
 In addition, you can tighten password security with the following configuration settings:
 

en/08_Changelogs/6.0.0.md

@@ -13,6 +13,7 @@ title: 6.0.0 (unreleased)
   - [Changes to scaffolded form fields](#scaffolded-fields)
   - [`SiteTree` uses form field scaffolding](#sitetree-scaffolding)
   - [Changes to the templating/view layer](#view-layer)
+  - [Changes to password validation](#password-validation)
   - [Other new features](#other-new-features)
 - [Dependency changes](#dependency-changes)
   - [`intervention/image` has been upgraded from v2 to v3](#intervention-image)
@@ -29,6 +30,7 @@ title: 6.0.0 (unreleased)
 - [Other changes](#other-changes)
   - [MySQL 5 no longer supported](#mysql-5-support)
   - [`DBDecimal` default value](#dbdecimal-default-value)
+  - [`RedirectorPage` validation](#redirectorpage-validation)
 - [Full list of removed and changed API (by module, alphabetically)](#api-removed-and-changed)
 
 ## Features and enhancements
@@ -450,12 +452,54 @@ The one change we specifically want to call out is for [`ModelData::obj()`](api:
 
 See the [full list of removed and changed API](#api-removed-and-changed) to see all of the API with updated typing.
 
-### Other new features and small changes {#other-new-features}
+### Changes to password validation {#password-validation}
+
+#### `PasswordValidator` changes
+
+The deprecated `SilverStripe\Security\PasswordValidator` class has been renamed to [`RulesPasswordValidator`](api:SilverStripe\Security\Validation\RulesPasswordValidator) and is now optional.
+
+The default password validator is now [`EntropyPasswordValidator`](api:SilverStripe\Security\Validation\EntropyPasswordValidator) which is powered by the [`PasswordStrength` constraint](https://symfony.com/doc/current/reference/constraints/PasswordStrength.html) in `symfony/validator`. This constraint determines if a password is strong enough based on its entropy, rather than on arbitrary rules about what characters it contains.
+
+You can change the required strength of valid passwords by setting the [`EntropyPasswordValidator.password_strength`](api:SilverStripe\Security\Validation\EntropyPasswordValidator->password_strength) configuration property to one of the valid [minScore values](https://symfony.com/doc/current/reference/constraints/PasswordStrength.html#minscore):
+
+```yml
+SilverStripe\Security\Validation\EntropyPasswordValidator:
+  password_strength: 4
+```
+
+`EntropyPasswordValidator` also has the same options for avoiding repeate uses of the same password that `RulesPasswordValidator` has.
+
+This does not retroactively affect existing passwords, but will affect any new passwords (e.g. new members or changing the password of an existing member).
+
+If you want to revert to the validator that was used in CMS 5, you can do so with this YAML configuration:
+
+```yml
+---
+After: '#corepasswords'
+---
+SilverStripe\Core\Injector\Injector:
+  SilverStripe\Security\Validation\PasswordValidator:
+    class: 'SilverStripe\Security\Validation\RulesPasswordValidator'
+```
+
+See [passwords](/developer_guides/security/secure_coding/#passwords) for more information about password validation.
+
+#### `ConfirmedPasswordField` changes
+
+If [ConfirmedPasswordField->requireStrongPassword](api:SilverStripe\Forms\ConfirmedPasswordField->requireStrongPassword) is set to true, the old behaviour was to validate that at least one digit and one alphanumeric character was included. This meant that you could have a password like "a1" and it would be considered "strong".
+
+This has been changed to use the [`PasswordStrength` constraint](https://symfony.com/doc/current/reference/constraints/PasswordStrength.html) in `symfony/validator` instead. Now a password is considered "strong" based on its level of entropy.
+
+You can change the level of entropy required by passing one of the valid [minScore values](https://symfony.com/doc/current/reference/constraints/PasswordStrength.html#minscore) into [`api:SilverStripe\Forms\ConfirmedPasswordField::setMinPasswordStrength()`](ConfirmedPasswordField::setMinPasswordStrength()).
+
+### Other new features
 
 - Native indexed PHP arrays can now be passed into templates and iterated over with `<% loop $MyArray %>`. Under the hood they are wrapped in [`ArrayList`](api:SilverStripe\Model\List\ArrayList), so you can get the count using `$Count` and use `<% if $ArrayList %>` as a shortcut for `<% if $ArrayList.Count %>`. Other functionality from `ArrayList` such as filtering and sorting cannot be used on arrays since they don't have keys to filter or sort against.
 - Modules no longer need to have a root level `_config.php` or `_config` directory to be recognised as a Silverstripe CMS module. They will now be recognised as a module if they have a `composer.json` file with a `type` of `silverstripe-vendormodule` or `silverstripe-theme`.
 - A new [`DataObject::getCMSEditLink()`](api:SilverStripe\ORM\DataObject::getCMSEditLink()) method has been added, which returns `null` by default. This provides more consistency for that method which has previously been inconsistently applied to various subclasses of `DataObject`. See [managing records](/developer_guides/model/managing_records/#getting-an-edit-link) for more details about providing sane values for this method in your own subclasses.
 - The `CMSEditLink()` method on many `DataObject` subclasses has been renamed to `getCMSEditLink()`.
+- The [`UrlField`](api:SilverStripe\Forms\UrlField) class has some new API for setting which protocols are allowed for valid URLs.
+- The [`EmailField`](api:SilverStripe\Forms\EmailField) class now uses `symfony/validator` to handle its validation logic, where previously this was validated with a custom regex.
 
 ## Dependency changes
 
@@ -657,6 +701,10 @@ MySQL 5.6 and 5.7 are no longer supported. The minimum supported version is MySQ
 
 Previously if an invalid default value was provided for a [`DBDecimal`](api:SilverStripe\ORM\FieldType\DBDecimal) database column, it would silently set the defalt value to `0`. This will now throw an exception instead, so that you're aware your configured value is invalid and can correct it.
 
+## `RedirectorPage` validation
+
+[`RedirectorPage`](api:SilverStripe\CMS\Model\RedirectorPage) now uses the [`Url` constraint](https://symfony.com/doc/current/reference/constraints/Url.html) from `symfony/validator` to validate the `ExternalURL` field. It will no longer add `http://` to the start of URLs for you if you're missing a protocol - instead, a validation error message will be displayed.
+
 ### Full list of removed and changed API (by module, alphabetically) {#api-removed-and-changed}
 
 <!--- Changes below this line will be automatically regenerated -->