#850 Add setting specifying which password hashes should be checked

src/main/java/fr/xephi/authme/settings/EnumSetProperty.java

@@ -0,0 +1,43 @@
+package fr.xephi.authme.settings;
+
+import com.github.authme.configme.properties.Property;
+import com.github.authme.configme.resource.PropertyResource;
+
+import java.util.List;
+import java.util.stream.Collectors;
+
+/**
+ * Property whose value is a set of entries of a given enum.
+ */
+// TODO https://github.com/AuthMe/ConfigMe/issues/27: Should be a Property of Set<E> type
+public class EnumSetProperty<E extends Enum<E>> extends Property<List<E>> {
+
+    private final Class<E> enumClass;
+
+    public EnumSetProperty(Class<E> enumClass, String path, List<E> defaultValue) {
+        super(path, defaultValue);
+        this.enumClass = enumClass;
+    }
+
+    @Override
+    protected List<E> getFromResource(PropertyResource resource) {
+        List<?> elements = resource.getList(getPath());
+        if (elements != null) {
+            return elements.stream()
+                .map(val -> toEnum(String.valueOf(val)))
+                .filter(e -> e != null)
+                .distinct()
+                .collect(Collectors.toList());
+        }
+        return null;
+    }
+
+    private E toEnum(String str) {
+        for (E e : enumClass.getEnumConstants()) {
+            if (str.equalsIgnoreCase(e.name())) {
+                return e;
+            }
+        }
+        return null;
+    }
+}

src/main/java/fr/xephi/authme/settings/SettingsMigrationService.java

@@ -7,6 +7,7 @@ import com.google.common.base.Objects;
 import fr.xephi.authme.ConsoleLogger;
 import fr.xephi.authme.output.LogLevel;
 import fr.xephi.authme.settings.properties.PluginSettings;
+import fr.xephi.authme.settings.properties.SecuritySettings;
 
 import java.io.File;
 import java.io.FileWriter;
@@ -49,6 +50,7 @@ public class SettingsMigrationService extends PlainMigrationService {
             | migrateForceSpawnSettings(resource)
             | changeBooleanSettingToLogLevelProperty(resource)
             | hasOldHelpHeaderProperty(resource)
+            | hasSupportOldPasswordProperty(resource)
             || hasDeprecatedProperties(resource);
     }
 
@@ -163,6 +165,16 @@ public class SettingsMigrationService extends PlainMigrationService {
         return false;
     }
 
+    private static boolean hasSupportOldPasswordProperty(PropertyResource resource) {
+        String path = "settings.security.supportOldPasswordHash";
+        if (resource.contains(path)) {
+            ConsoleLogger.warning("Property '" + path + "' is no longer supported. "
+                + "Use '" + SecuritySettings.LEGACY_HASHES.getPath() + "' instead.");
+            return true;
+        }
+        return false;
+    }
+
     /**
      * Checks for an old property path and moves it to a new path if present.
      *

src/main/java/fr/xephi/authme/settings/properties/SecuritySettings.java

@@ -4,7 +4,9 @@ import com.github.authme.configme.Comment;
 import com.github.authme.configme.SettingsHolder;
 import com.github.authme.configme.properties.Property;
 import fr.xephi.authme.security.HashAlgorithm;
+import fr.xephi.authme.settings.EnumSetProperty;
 
+import java.util.Collections;
 import java.util.List;
 
 import static com.github.authme.configme.properties.PropertyInitializer.newLowercaseListProperty;
@@ -74,11 +76,15 @@ public class SecuritySettings implements SettingsHolder {
     public static final Property<Integer> DOUBLE_MD5_SALT_LENGTH =
         newProperty("settings.security.doubleMD5SaltLength", 8);
 
-    @Comment({"If password checking return false, do we need to check with all",
-        "other password algorithm to check an old password?",
-        "AuthMe will update the password to the new password hash"})
-    public static final Property<Boolean> SUPPORT_OLD_PASSWORD_HASH =
-        newProperty("settings.security.supportOldPasswordHash", false);
+    @Comment({
+        "If a password check fails, AuthMe will also try to check with the following hash methods.",
+        "Use this setting when you change from one hash method to another.",
+        "AuthMe will update the password to the new hash. Example:",
+        "legacyHashes:",
+        "- 'SHA1'"
+    })
+    public static final Property<List<HashAlgorithm>> LEGACY_HASHES =
+        new EnumSetProperty<>(HashAlgorithm.class, "settings.security.legacyHashes", Collections.emptyList());
 
     @Comment({"Prevent unsafe passwords from being used; put them in lowercase!",
         "You should always set 'help' as unsafePassword due to possible conflicts.",