Fix describeHashAlgos tool task

- Handle case when Argon2 library is not loaded
- Account for hash algorithms with `null` as associated impl. class

docs/hash_algorithms.md

@@ -1,5 +1,5 @@
 <!-- AUTO-GENERATED FILE! Do not edit this directly -->
-<!-- File auto-generated on Thu Oct 19 21:41:21 CEST 2017. See docs/hashmethods/hash_algorithms.tpl.md -->
+<!-- File auto-generated on Sat Oct 28 13:29:59 CEST 2017. See docs/hashmethods/hash_algorithms.tpl.md -->
 
 ## Hash Algorithms
 AuthMe supports the following hash algorithms for storing your passwords safely.
@@ -79,4 +79,4 @@ or bad.
 
 ---
 
-This page was automatically generated on the [AuthMe/AuthMeReloaded repository](https://github.com/AuthMe/AuthMeReloaded/tree/master/docs/) on Thu Oct 19 21:41:21 CEST 2017
+This page was automatically generated on the [AuthMe/AuthMeReloaded repository](https://github.com/AuthMe/AuthMeReloaded/tree/master/docs/) on Sat Oct 28 13:29:59 CEST 2017

src/test/java/tools/docs/hashmethods/EncryptionMethodInfoGatherer.java

@@ -3,8 +3,10 @@ package tools.docs.hashmethods;
 import ch.jalu.injector.Injector;
 import ch.jalu.injector.InjectorBuilder;
 import com.google.common.collect.ImmutableSet;
+import fr.xephi.authme.ConsoleLogger;
 import fr.xephi.authme.TestHelper;
 import fr.xephi.authme.security.HashAlgorithm;
+import fr.xephi.authme.security.crypts.Argon2;
 import fr.xephi.authme.security.crypts.EncryptionMethod;
 import fr.xephi.authme.security.crypts.HexSaltedMethod;
 import fr.xephi.authme.security.crypts.description.AsciiRestricted;
@@ -13,10 +15,12 @@ import fr.xephi.authme.security.crypts.description.Recommendation;
 import fr.xephi.authme.settings.Settings;
 
 import java.lang.annotation.Annotation;
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.LinkedHashMap;
 import java.util.Map;
 import java.util.Set;
+import java.util.logging.Logger;
 
 import static org.mockito.Mockito.mock;
 
@@ -34,6 +38,7 @@ public class EncryptionMethodInfoGatherer {
     private Map<HashAlgorithm, MethodDescription> descriptions;
 
     public EncryptionMethodInfoGatherer() {
+        ConsoleLogger.setLogger(Logger.getAnonymousLogger()); // set logger because of Argon2.isLibraryLoaded()
         descriptions = new LinkedHashMap<>();
         constructDescriptions();
     }
@@ -44,7 +49,7 @@ public class EncryptionMethodInfoGatherer {
 
     private void constructDescriptions() {
         for (HashAlgorithm algorithm : HashAlgorithm.values()) {
-            if (!HashAlgorithm.CUSTOM.equals(algorithm) && !algorithm.getClazz().isAnnotationPresent(Deprecated.class)) {
+            if (algorithm.getClazz() != null && !algorithm.getClazz().isAnnotationPresent(Deprecated.class)) {
                 MethodDescription description = createDescription(algorithm);
                 descriptions.put(algorithm, description);
             }
@@ -53,10 +58,7 @@ public class EncryptionMethodInfoGatherer {
 
     private static MethodDescription createDescription(HashAlgorithm algorithm) {
         Class<? extends EncryptionMethod> clazz = algorithm.getClazz();
-        EncryptionMethod method = injector.createIfHasDependencies(clazz);
-        if (method == null) {
-            throw new NullPointerException("Method for '" + algorithm + "' is null");
-        }
+        EncryptionMethod method = createEncryptionMethod(clazz);
         MethodDescription description = new MethodDescription(clazz);
         description.setHashLength(method.computeHash("test", "user").getHash().length());
         description.setHasSeparateSalt(method.hasSeparateSalt());
@@ -74,6 +76,19 @@ public class EncryptionMethodInfoGatherer {
         return description;
     }
 
+    private static EncryptionMethod createEncryptionMethod(Class<? extends EncryptionMethod> clazz) {
+        if (clazz == Argon2.class && !Argon2.isLibraryLoaded()) {
+            // The library for Argon2 isn't installed, so override the hash implementation to avoid using the library
+            return new Argon2DummyExtension();
+        }
+
+        EncryptionMethod method = injector.createIfHasDependencies(clazz);
+        if (method == null) {
+            throw new NullPointerException("Failed to instantiate '" + clazz + "'. Is a dependency missing?");
+        }
+        return method;
+    }
+
     private static Map<Class<?>, Annotation> gatherAnnotations(Class<?> methodClass) {
         // Note ljacqu 20151231: The map could be Map<Class<? extends Annotation>, Annotation> and it has the constraint
         // that for a key Class<T>, the value is of type T. We write a simple "Class<?>" for brevity.
@@ -140,11 +155,17 @@ public class EncryptionMethodInfoGatherer {
         Settings settings = mock(Settings.class);
         TestHelper.returnDefaultsForAllProperties(settings);
 
-        // By passing some bogus "package" to the constructor, the injector will throw if it needs to
-        // instantiate any dependency other than what we provide.
+        // Limit instantiation to the crypts package only so any dependencies need to be passed explicitly
         Injector injector = new InjectorBuilder().addDefaultHandlers("fr.xephi.authme.security.crypts").create();
         injector.register(Settings.class, settings);
         return injector;
     }
 
+    private static final class Argon2DummyExtension extends Argon2 {
+        @Override
+        public String computeHash(String password) {
+            // Argon2 produces hashes of 96 characters -> return dummy value with this length
+            return String.join("", Collections.nCopies(96, "."));
+        }
+    }
 }