added helper methods, suggested by @Hanmac

Author: sreichel

app/code/core/Mage/Admin/Model/User.php

@@ -7,6 +7,8 @@
  * @package    Mage_Admin
  */
 
+use Symfony\Component\Validator\ConstraintViolationListInterface;
+
 /**
  * Admin user model
  *
@@ -631,14 +633,8 @@ public function validate()
         }
 
         if (isset($password)) {
-            $minAdminPasswordLength = $this->getMinAdminPasswordLength();
             $violations = new ArrayObject();
-            $violations->append($validator->validatePassword(
-                value: $password,
-                minLength: $minAdminPasswordLength,
-                message: Mage::helper('adminhtml')->__('Password must include both numeric and alphabetic characters.'),
-                minMessage: Mage::helper('adminhtml')->__('Password must be at least of %d characters.', $minAdminPasswordLength),
-            ));
+            $violations->append($this->getPasswordValidator(value: $password));
 
             if ($this->hasPasswordConfirmation()) {
                 $violations->append($validator->validateIdentical(
@@ -671,6 +667,19 @@ public function validate()
         return (array) $errors;
     }
 
+    public function getPasswordValidator(mixed $value): ConstraintViolationListInterface
+    {
+        $min = $this->getMinAdminPasswordLength();
+        $validator  = $this->getValidationHelper();
+
+        return $validator->validatePassword(
+            value: $value,
+            min: $min,
+            minMessage: Mage::helper('adminhtml')->__('Password must be at least of %d characters.', $min),
+            regexMessage: Mage::helper('adminhtml')->__('Password must include both numeric and alphabetic characters.'),
+        );
+    }
+
     /**
      * Validate password against current user password
      * Returns TRUE or array of errors.
@@ -681,8 +690,7 @@ public function validate()
      */
     public function validateCurrentPassword($password)
     {
-        /** @var Mage_Core_Helper_Validate $validator */
-        $validator  = Mage::helper('core/validate');
+        $validator  = $this->getValidationHelper();
         $result     = [];
 
         if ($validator->validateNotEmpty($password)->count() > 0) {

app/code/core/Mage/Core/Helper/Validate.php

@@ -471,6 +471,7 @@ public function validateNotEmpty(
         mixed $payload = null
     ): ConstraintViolationListInterface {
         $validator = self::getValidator();
+
         return $validator->validate($value, [
             new Constraints\NotBlank(
                 options: $options,
@@ -483,17 +484,33 @@ public function validateNotEmpty(
         ]);
     }
 
-    public function validatePassword(mixed $value, int $minLength, string $message, string $minMessage): ConstraintViolationListInterface
-    {
+    /**
+     * Validates that a password meets given constraints.
+     */
+    public function validatePassword(
+        mixed   $value,
+        ?int    $min = null,
+        ?int    $max = null,
+        ?string $emptyMessage = null,
+        ?string $minMessage = null,
+        ?string $maxMessage = null,
+        ?string $regexMessage = null,
+    ): ConstraintViolationListInterface {
         $validator = self::getValidator();
+
         return $validator->validate($value, [
+            new Constraints\NotBlank(
+                message: $emptyMessage,
+            ),
             new Constraints\Length(
-                min: $minLength,
+                min: $min,
+                max: $max,
                 minMessage: $minMessage,
+                maxMessage: $maxMessage,
             ),
             new Constraints\Regex(
                 pattern: '/^(?=.*[a-z])(?=.*[0-9]).+$/iu',
-                message: $message,
+                message: $regexMessage,
             ),
         ]);
     }

app/code/core/Mage/Customer/Model/Customer.php

@@ -7,6 +7,8 @@
  * @package    Mage_Customer
  */
 
+use Symfony\Component\Validator\ConstraintViolationListInterface;
+
 /**
  * Customer model
  *
@@ -1096,26 +1098,11 @@ public function validate()
             message: Mage::helper('customer')->__('Invalid email address "%s".', $email),
         ));
 
-        $password = $this->getPassword();
-        $minPasswordLength = $this->getMinPasswordLength();
+        $violations->append($this->getPasswordValidator(value: $this->getPassword()));
 
-        $violations->append($validator->validateNotEmpty(
-            value: $password,
-            message: Mage::helper('customer')->__('The password cannot be empty.'),
-        ));
-
-        $violations->append($validator->validateLength(
-            value: $password,
-            min: $minPasswordLength,
-            max: self::MAXIMUM_PASSWORD_LENGTH,
-            minMessage: Mage::helper('customer')->__('The minimum password length is %s', $minPasswordLength),
-            maxMessage: Mage::helper('customer')->__('Please enter a password with at most %s characters.', self::MAXIMUM_PASSWORD_LENGTH),
-        ));
-
-        $confirmation = $this->getPasswordConfirmation();
         $violations->append($validator->validateIdentical(
-            value: $confirmation,
-            compare: $password,
+            value: $this->getPasswordConfirmation(),
+            compare: $this->getPassword(),
             message: Mage::helper('customer')->__('Please make sure your passwords match.'),
         ));
 
@@ -1159,25 +1146,11 @@ public function validateResetPassword()
         $validator  = $this->getValidationHelper();
         $violations = new ArrayObject();
 
-        $password = $this->getPassword();
-        $minPasswordLength = $this->getMinPasswordLength();
-
-        $violations->append($validator->validateNotEmpty(
-            value: $password,
-            message: Mage::helper('customer')->__('The password cannot be empty.'),
-        ));
-
-        $violations->append($validator->validateLength(
-            value: $password,
-            min: $minPasswordLength,
-            max: self::MAXIMUM_PASSWORD_LENGTH,
-            minMessage: Mage::helper('customer')->__('The minimum password length is %s', $minPasswordLength),
-            maxMessage: Mage::helper('customer')->__('Please enter a password with at most %s characters.', self::MAXIMUM_PASSWORD_LENGTH),
-        ));
+        $violations->append($this->getPasswordValidator(value: $this->getPassword()));
 
         $violations->append($validator->validateIdentical(
             value: $this->getPasswordConfirmation(),
-            compare: $password,
+            compare: $this->getPassword(),
             message: Mage::helper('customer')->__('Please make sure your passwords match.'),
         ));
 
@@ -1189,6 +1162,21 @@ public function validateResetPassword()
         return (array) $errors;
     }
 
+    public function getPasswordValidator(mixed $value): ConstraintViolationListInterface
+    {
+        $min = $this->getMinPasswordLength();
+        $validator  = $this->getValidationHelper();
+
+        return $validator->validatePassword(
+            value: $value,
+            min: $min,
+            max: self::MAXIMUM_PASSWORD_LENGTH,
+            emptyMessage: Mage::helper('customer')->__('The password cannot be empty.'),
+            minMessage: Mage::helper('customer')->__('The minimum password length is %s', $min),
+            maxMessage: Mage::helper('customer')->__('Please enter a password with at most %s characters.', self::MAXIMUM_PASSWORD_LENGTH),
+        );
+    }
+
     /**
      * Import customer data from text array
      *