diff --git a/lib/Crypto/AbstractAlgorithm.php b/lib/Crypto/AbstractAlgorithm.php
index 9556d78..09bbbe6 100644
--- a/lib/Crypto/AbstractAlgorithm.php
+++ b/lib/Crypto/AbstractAlgorithm.php
@@ -74,4 +74,12 @@ abstract class AbstractAlgorithm implements IPasswordAlgorithm
      * @inheritdoc
      */
     public abstract function getPasswordHash($password);
+
+    /**
+     * @inheritdoc
+     */
+    public function configuration()
+    {
+        return [];
+    }
 }
diff --git a/lib/Crypto/CryptArgon2.php b/lib/Crypto/CryptArgon2.php
index ed4aafb..535f1e8 100644
--- a/lib/Crypto/CryptArgon2.php
+++ b/lib/Crypto/CryptArgon2.php
@@ -100,6 +100,27 @@ class CryptArgon2 extends AbstractAlgorithm
         );
     }
 
+    /**
+     * @inheritdoc
+     */
+    public function configuration()
+    {
+        return [
+            [
+                "name" => "memoryCost", "visible_name" => "Memory cost (KiB)",
+                "default" => PASSWORD_ARGON2_DEFAULT_MEMORY_COST, "min" => 1, "max" => 1048576
+            ],
+            [
+                "name" => "timeCost", "visible_name" => "Time cost",
+                "default" => PASSWORD_ARGON2_DEFAULT_TIME_COST, "min" => 1, "max" => 1024
+            ],
+            [
+                "name" => "threads", "visible_name" => "Threads",
+                "default" => PASSWORD_ARGON2_DEFAULT_THREADS, "min" => 1, "max" => 1024
+            ]
+        ];
+    }
+
     /**
      * @inheritdoc
      */
diff --git a/lib/Crypto/CryptBlowfish.php b/lib/Crypto/CryptBlowfish.php
index 6e1b8a5..a3e2577 100644
--- a/lib/Crypto/CryptBlowfish.php
+++ b/lib/Crypto/CryptBlowfish.php
@@ -67,6 +67,19 @@ class CryptBlowfish extends AbstractAlgorithm
         );
     }
 
+    /**
+     * @inheritdoc
+     */
+    public function configuration()
+    {
+        return [
+            [
+                "name" => "cost", "visible_name" => "Cost", "default" => 10,
+                "min" => 4, "max" => 31
+            ]
+        ];
+    }
+
     /**
      * Get the algorithm name.
      *
diff --git a/lib/Crypto/CryptExtendedDES.php b/lib/Crypto/CryptExtendedDES.php
index d6654c4..235e563 100644
--- a/lib/Crypto/CryptExtendedDES.php
+++ b/lib/Crypto/CryptExtendedDES.php
@@ -48,6 +48,19 @@ class CryptExtendedDES extends AbstractCrypt
         $this->iterationCount = $iterationCount;
     }
 
+    /**
+     * @inheritdoc
+     */
+    public function configuration()
+    {
+        return [
+            [
+                "name" => "iterations", "visible_name" => "Iterations", "default" => 1000,
+                "min" => 0, "max" => 16777215
+            ]
+        ];
+    }
+
     /**
      * @inheritdoc
      */
@@ -76,7 +89,7 @@ class CryptExtendedDES extends AbstractCrypt
         while ($number) {
             $rem = $number % $base;
             $number = (int)($number / $base);
-            $arr[] = $alphabet[$rem];
+            $chars[] = $alphabet[$rem];
         }
 
         return str_pad(implode($chars), 4, ".", STR_PAD_RIGHT);
diff --git a/lib/Crypto/CryptSHA256.php b/lib/Crypto/CryptSHA256.php
index b4e2b41..75515eb 100644
--- a/lib/Crypto/CryptSHA256.php
+++ b/lib/Crypto/CryptSHA256.php
@@ -49,6 +49,19 @@ class CryptSHA256 extends AbstractCrypt
         $this->rounds = $rounds;
     }
 
+    /**
+     * @inheritdoc
+     */
+    public function configuration()
+    {
+        return [
+            [
+                "name" => "rounds", "visible_name" => "Rounds", "default" => 5000,
+                "min" => 1000, "max" => 999999999
+            ]
+        ];
+    }
+
     /**
      * @inheritdoc
      */
diff --git a/lib/Crypto/CryptSHA512.php b/lib/Crypto/CryptSHA512.php
index e32238f..b638175 100644
--- a/lib/Crypto/CryptSHA512.php
+++ b/lib/Crypto/CryptSHA512.php
@@ -49,6 +49,19 @@ class CryptSHA512 extends AbstractCrypt
         $this->rounds = $rounds;
     }
 
+    /**
+     * @inheritdoc
+     */
+    public function configuration()
+    {
+        return [
+            [
+                "name" => "rounds", "visible_name" => "Rounds", "default" => 5000,
+                "min" => 1000, "max" => 999999999
+            ]
+        ];
+    }
+
     /**
      * @inheritdoc
      */
diff --git a/lib/Crypto/IPasswordAlgorithm.php b/lib/Crypto/IPasswordAlgorithm.php
index 47ba961..1f33356 100644
--- a/lib/Crypto/IPasswordAlgorithm.php
+++ b/lib/Crypto/IPasswordAlgorithm.php
@@ -56,4 +56,13 @@ interface IPasswordAlgorithm
      * @return boolean True if the password is correct, false otherwise.
      */
     public function checkPassword($password, $dbHash);
+
+    /**
+     * Configuration for the algorithm.
+     * The return array should contain entries which define keys:
+     * name, visible_name, default, min, max.
+     *
+     * @return array The configuration array.
+     */
+    public function configuration();
 }
diff --git a/lib/Crypto/Phpass.php b/lib/Crypto/Phpass.php
index d193917..dae4eab 100644
--- a/lib/Crypto/Phpass.php
+++ b/lib/Crypto/Phpass.php
@@ -143,6 +143,19 @@ class Phpass extends AbstractAlgorithm
         return $output;
     }
 
+    /**
+     * @inheritdoc
+     */
+    public function configuration()
+    {
+        return [
+            [
+                "name" => "iterations", "visible_name" => "Iterations (log2)",
+                "default" => 8, "min" => 4, "max" => 31
+            ]
+        ];
+    }
+
     /**
      * @inheritdoc
      */
diff --git a/tests/Crypto/CryptExtendedDESTest.php b/tests/Crypto/CryptExtendedDESTest.php
index c5627e0..5f820b6 100644
--- a/tests/Crypto/CryptExtendedDESTest.php
+++ b/tests/Crypto/CryptExtendedDESTest.php
@@ -41,7 +41,7 @@ class CryptExtendedDESTest extends TestCase
     public function testCheckPassword()
     {
         $this->assertTrue(
-            $this->crypto->checkPassword("password", "..UZoIyj/Hy/c")
+            $this->crypto->checkPassword("password", "cDRpdxPmHpzS.")
         );
     }