#1150 - Add Argon2 support

- Add argon2 implementation

- Extract argon2 library check to method on Argon 2
- Add link to Wiki page on errors
- Check within Argon2Test if the test cases should be run, not in the abstract parent

src/main/java/fr/xephi/authme/AuthMe.java

@@ -23,6 +23,8 @@ import fr.xephi.authme.listener.PlayerListener18;
 import fr.xephi.authme.listener.PlayerListener19;
 import fr.xephi.authme.listener.PlayerListener19Spigot;
 import fr.xephi.authme.listener.ServerListener;
+import fr.xephi.authme.security.HashAlgorithm;
+import fr.xephi.authme.security.crypts.Argon2;
 import fr.xephi.authme.security.crypts.Sha256;
 import fr.xephi.authme.service.BackupService;
 import fr.xephi.authme.service.BukkitService;
@@ -267,6 +269,13 @@ public class AuthMe extends JavaPlugin {
             && settings.getProperty(EmailSettings.SMTP_PORT) != 25) {
             ConsoleLogger.warning("Note: You have set Email.useTls to false but this only affects mail over port 25");
         }
+        // Check if argon2 library is present and can be loaded
+        if (settings.getProperty(SecuritySettings.PASSWORD_HASH).equals(HashAlgorithm.ARGON2)
+            && !Argon2.isLibraryLoaded()) {
+            ConsoleLogger.warning("WARNING!!! You use Argon2 Hash Algorithm method but we can't find the Argon2 "
+                + "library on your system! See https://github.com/AuthMe/AuthMeReloaded/wiki/Argon2-as-Password-Hash");
+            stopOrUnload();
+        }
     }
 
     /**

src/main/java/fr/xephi/authme/security/HashAlgorithm.java

@@ -7,6 +7,7 @@ import fr.xephi.authme.security.crypts.EncryptionMethod;
  */
 public enum HashAlgorithm {
 
+    ARGON2(fr.xephi.authme.security.crypts.Argon2.class),
     BCRYPT(fr.xephi.authme.security.crypts.BCrypt.class),
     BCRYPT2Y(fr.xephi.authme.security.crypts.BCrypt2y.class),
     CRAZYCRYPT1(fr.xephi.authme.security.crypts.CrazyCrypt1.class),

src/main/java/fr/xephi/authme/security/crypts/Argon2.java

@@ -0,0 +1,48 @@
+package fr.xephi.authme.security.crypts;
+
+import de.mkammerer.argon2.Argon2Constants;
+import de.mkammerer.argon2.Argon2Factory;
+import fr.xephi.authme.ConsoleLogger;
+import fr.xephi.authme.security.crypts.description.HasSalt;
+import fr.xephi.authme.security.crypts.description.Recommendation;
+import fr.xephi.authme.security.crypts.description.SaltType;
+import fr.xephi.authme.security.crypts.description.Usage;
+
+@Recommendation(Usage.RECOMMENDED)
+@HasSalt(value = SaltType.TEXT, length = Argon2Constants.DEFAULT_SALT_LENGTH)
+// Note: Argon2 is actually a salted algorithm but salt generation is handled internally
+// and isn't exposed to the outside, so we treat it as an unsalted implementation
+public class Argon2 extends UnsaltedMethod {
+
+    private de.mkammerer.argon2.Argon2 argon2;
+
+    public Argon2() {
+        argon2 = Argon2Factory.create();
+    }
+
+    /**
+     * Checks if the argon2 library is available in java.library.path.
+     *
+     * @return true if the library is present, false otherwise
+     */
+    public static boolean isLibraryLoaded() {
+        try {
+            System.loadLibrary("argon2");
+            return true;
+        } catch (UnsatisfiedLinkError e) {
+            ConsoleLogger.logException(
+                "Cannot find argon2 library: https://github.com/AuthMe/AuthMeReloaded/wiki/Argon2-as-Password-Hash", e);
+        }
+        return false;
+    }
+
+    @Override
+    public String computeHash(String password) {
+        return argon2.hash(2, 65536, 1, password);
+    }
+
+    @Override
+    public boolean comparePassword(String password, HashedPassword hashedPassword, String name) {
+        return argon2.verify(hashedPassword.getHash(), password);
+    }
+}

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

@@ -55,8 +55,9 @@ public final class SecuritySettings implements SettingsHolder {
     @Comment({
         "Possible values: SHA256, BCRYPT, BCRYPT2Y, PBKDF2, SALTEDSHA512,",
         "MYBB, IPB3, PHPBB, PHPFUSION, SMF, XENFORO, XAUTH, JOOMLA, WBB3, WBB4, MD5VB,",
-        "PBKDF2DJANGO, WORDPRESS, ROYALAUTH, CUSTOM (for developers only). See full list at",
-        "https://github.com/AuthMe/AuthMeReloaded/blob/master/docs/hash_algorithms.md"
+        "PBKDF2DJANGO, WORDPRESS, ROYALAUTH, ARGON2, CUSTOM (for developers only). See full list at",
+        "https://github.com/AuthMe/AuthMeReloaded/blob/master/docs/hash_algorithms.md",
+        "If you use ARGON2, check that you have the argon2 c library on your system"
     })
     public static final Property<HashAlgorithm> PASSWORD_HASH =
         newProperty(HashAlgorithm.class, "settings.security.passwordHash", HashAlgorithm.SHA256);