Fix excessive memory allocation described in #4

.gitignore

@@ -89,3 +89,6 @@ aws.properties
 
 .vagrant/
 Vagrantfile
+
+.gradle/
+build/

README.md

@@ -1,13 +1,13 @@
 # Argon2 Java implementation
 
-This is a pure Java implementation of [Argon2](https://github.com/P-H-C/phc-winner-argon2). It targets Java 6.
+This is a pure Java implementation of [Argon2](https://github.com/P-H-C/phc-winner-argon2). It targets Java 8.
 
-Many parts are just taken from the C code and converted to Java syntax - there shouldn't be any major performance bottlenecks anymore, but speed can't keep up quite with the C implementation.
+Many parts are just taken from the C code and converted to Java syntax. Runtime overhead compared to the C implementation is within 20 percent.
 
-Fair warning: this code is not well tested and not reviewed. It is not ready for production, use it on your own risk. Same applies for underlying Blake2b implementation.
+Fair warning: This code is neither excessively tested nor reviewed. Use it at your own risk. Same applies to the underlying Blake2b cryptographic hash implementation.
 
 ## Benchmarks
-[Rplots.pdf](benchmarks/Rplots.pdf)
+Old benchmark before memory optimization of the Java implementation: [Rplots.pdf](benchmarks/Rplots.pdf)
 
 Red is java, green the reference implementation and blue the optimized implementation with SSE-instructions - run on a i7-7700HQ with 16GB RAM.
 
@@ -33,67 +33,59 @@ Clone and install it:
 </dependency>
 ```
 
-<!---
 ## Gradle
 
 ```groovy
 compile 'at.gadermaier:argon2:1.0-SNAPSHOT'
 ```
--->
-## Usage
 
+## Usage
 
-```
-// Read password
+### Create encoded hash when a user is setting it's password
+```java
 char[] password = readPassword();
-
-// Generate salt
 String salt = generateRandomSalt();
 
 // Hash password - Builder pattern
-String hash = Argon2Factory.create()
-            .setIterations(2)
-            .setMemory(14)
-            .setParallelism(1)
-            .hash(password, salt);
-
-```
+String encodedHash = Argon2Factory.create()
+    .setIterations(2)
+    .setMemory(14)
+    .setParallelism(1)
+    .hash(password, salt).
+    .asEncoded();
+
+storeToDataBase(encodedHash);
 ```
-% java -jar argon2-0.1.jar
-usage: argon2 salt [-d | -i | -id] [-e | -r] [-h]   [-k <N> | -m <N>] [-l
-      <N>]  [-p <N>]  [-t <N>]
--d       Use Argon2d instead of Argon2i
--e       Output only encoded hash
--h       Print usage
--i       Use Argon2i (this is the default)
--id      Use Argon2id instead of Argon2i
--k <N>   Sets the memory usage of N KiB (default 2^12)
--l <N>   Sets hash output length to N bytes (default 32)
--m <N>   Sets the memory usage of 2^N KiB (default 12)
--p <N>   Sets parallelism to N (default 1)
--r       Output only the raw bytes of the hash
--t <N>   Sets the number of iterations to N (default = 3)
-Password is read from stdin
+
+### Verify that a user entered a correct password
+```java
+String password = readFromUser();
+String encodedHash = readFromDatabase();
+
+boolean match = Argon2().checkHash(encodedHash, password);
+if (match) {
+	loginUser();
+} else {
+	printInvalidUsernameOrPassword();
+}
 ```
 
 ## Blake2b
-The [blake2b Java implementation](https://github.com/alphazero/Blake2b) of [@alphazero](https://github.com/alphazero/) is used. Because no artifact is available on maven central, I copied the relevant class file into this project - for the sake of simplicity.
+The [blake2b Java implementation](https://github.com/alphazero/Blake2b) from [@alphazero](https://github.com/alphazero/) is used. Because no artifact is available on Maven Central the relevant class file is embedded in this project.
 
 ## License
 [MIT](https://opensource.org/licenses/MIT)
 
 ## TODO
 * Verification
-* Encoded result
 * Performance
+  * Can we get closer to the C implementation?
   * in Block.xorBlock(), the JIT actually already creates vector operations
 * Fix the build
   * Build library without commons-dependency, build executable with
   * maven central
   * add gradle support
-* Add Tests
-* ..
-
+* Add more Tests
 
 ## Contact
 [@andreas1327250](https://github.com/andreas1327250)

build.gradle

@@ -0,0 +1,44 @@
+plugins {
+    id 'java'
+}
+
+group 'rip.deadcode.argon2'
+version '0.1-SNAPSHOT'
+
+repositories {
+    mavenCentral()
+    maven {
+        url = "https://dl.bintray.com/minebreaker/test"
+    }
+}
+
+dependencies {
+    testCompile(
+            'org.junit.jupiter:junit-jupiter-api:5.3.2',
+            'de.mkammerer:argon2-jvm:2.5',
+            'com.google.truth:truth:0.42',
+//            'com.google.truth.extensions:truth-java8-extension:0.42',
+//            'org.mockito:mockito-core:2.23.4',
+//            'rip.deadcode:izvestia:0.2',
+//            'com.google.jimfs:jimfs:1.1'
+    )
+    testRuntime(
+    		'org.junit.jupiter:junit-jupiter-engine:5.3.2',
+            'de.mkammerer:argon2-jvm:2.5'
+	)
+}
+
+test {
+    useJUnitPlatform()
+}
+
+sourceCompatibility = 1.8
+targetCompatibility = 1.8
+
+compileJava {
+    options.encoding = 'UTF-8'
+}
+
+compileTestJava {
+    options.encoding = 'UTF-8'
+}

gradle/wrapper/gradle-wrapper.properties

@@ -0,0 +1,5 @@
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-5.2.1-all.zip
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists