add simple examples for password encoders

spring-boot/password-encoding/src/main/java/io/reflectoring/passwordencoding/encoder/Argon2Example.java

@@ -0,0 +1,18 @@
+package io.reflectoring.passwordencoding.encoder;
+
+import org.springframework.security.crypto.argon2.Argon2PasswordEncoder;
+
+public class Argon2Example {
+
+
+    public String encode(String plainPassword) {
+        int saltLength = 16; // salt length in bytes
+        int hashLength = 32; // hash length in bytes
+        int parallelism = 1; // currently is not supported
+        int memory = 4096; // memory costs
+        int iterations = 3;
+
+        Argon2PasswordEncoder argon2PasswordEncoder = new Argon2PasswordEncoder(saltLength, hashLength, parallelism, memory, iterations);
+        return argon2PasswordEncoder.encode(plainPassword);
+    }
+}

spring-boot/password-encoding/src/main/java/io/reflectoring/passwordencoding/encoder/BCryptExample.java

@@ -0,0 +1,14 @@
+package io.reflectoring.passwordencoding.encoder;
+
+import org.springframework.security.crypto.bcrypt.BCryptPasswordEncoder;
+
+import java.security.SecureRandom;
+
+public class BCryptExample {
+
+    public String encode(String plainPassword) {
+        int strength = 10;
+        BCryptPasswordEncoder bCryptPasswordEncoder = new BCryptPasswordEncoder(strength, new SecureRandom());
+        return bCryptPasswordEncoder.encode(plainPassword);
+    }
+}

spring-boot/password-encoding/src/main/java/io/reflectoring/passwordencoding/encoder/Pbkdf2Example.java

@@ -0,0 +1,16 @@
+package io.reflectoring.passwordencoding.encoder;
+
+import org.springframework.security.crypto.password.Pbkdf2PasswordEncoder;
+
+public class Pbkdf2Example {
+
+    public String encode(String plainPassword) {
+
+        String pepper = "pepper"; // secret key used by password encoding
+        int iterations = 200000; // number of hash iteration
+        int hashWidth = 256; // hash with in bits
+
+        Pbkdf2PasswordEncoder pbkdf2PasswordEncoder = new Pbkdf2PasswordEncoder(pepper, iterations, hashWidth);
+        return pbkdf2PasswordEncoder.encode(plainPassword);
+    }
+}

spring-boot/password-encoding/src/main/java/io/reflectoring/passwordencoding/encoder/SCryptExample.java

@@ -0,0 +1,17 @@
+package io.reflectoring.passwordencoding.encoder;
+
+import org.springframework.security.crypto.scrypt.SCryptPasswordEncoder;
+
+public class SCryptExample {
+
+    public String encode(String plainPassword) {
+        int cpuCost = (int) Math.pow(2, 14); // factor to increase CPU costs
+        int memoryCost = 8; // factor to increases memory usage
+        int parallelization = 1; // currently  nor supported by Spring Security
+        int keyLength = 32; // key length in bytes
+        int saltLength = 64; // salt length in bytes
+
+        SCryptPasswordEncoder sCryptPasswordEncoder = new SCryptPasswordEncoder(cpuCost, memoryCost, parallelization, keyLength, saltLength);
+        return  sCryptPasswordEncoder.encode(plainPassword);
+    }
+}

spring-boot/password-encoding/src/test/java/io/reflectoring/passwordencoding/encoder/Argon2ExampleTest.java

@@ -0,0 +1,22 @@
+package io.reflectoring.passwordencoding.encoder;
+
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.AssertionsForClassTypes.assertThat;
+
+class Argon2ExampleTest {
+
+    private Argon2Example argon2Example = new Argon2Example();
+
+    @Test
+    void encode() {
+        // given
+        String plainPassword = "password";
+
+        // when
+        String actual = argon2Example.encode(plainPassword);
+
+        // then
+        assertThat(actual).startsWith("$argon2id$v=19$m=4096,t=3,p=1");
+    }
+}

spring-boot/password-encoding/src/test/java/io/reflectoring/passwordencoding/encoder/BCryptExampleTest.java

@@ -0,0 +1,22 @@
+package io.reflectoring.passwordencoding.encoder;
+
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.AssertionsForClassTypes.assertThat;
+
+class BCryptExampleTest {
+
+    private BCryptExample bcryptExample = new BCryptExample();
+
+    @Test
+    void encode() {
+        // given
+        String plainPassword = "password";
+
+        // when
+        String encoded = bcryptExample.encode(plainPassword);
+
+        // then
+        assertThat(encoded).startsWith("$2a$10");
+    }
+}

spring-boot/password-encoding/src/test/java/io/reflectoring/passwordencoding/encoder/Pbkdf2ExampleTest.java

@@ -0,0 +1,22 @@
+package io.reflectoring.passwordencoding.encoder;
+
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.AssertionsForClassTypes.assertThat;
+
+class Pbkdf2ExampleTest {
+
+    private Pbkdf2Example pbkdf2Example = new Pbkdf2Example();
+
+    @Test
+    void encode() {
+        // given
+        String plainPassword = "plainPassword";
+
+        // when
+        String actual = pbkdf2Example.encode(plainPassword);
+
+        // then
+        assertThat(actual).hasSize(80);
+    }
+}

spring-boot/password-encoding/src/test/java/io/reflectoring/passwordencoding/encoder/SCryptExampleTest.java

@@ -0,0 +1,23 @@
+package io.reflectoring.passwordencoding.encoder;
+
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.AssertionsForClassTypes.assertThat;
+
+class SCryptExampleTest {
+
+    private SCryptExample sCryptExample = new SCryptExample();
+
+    @Test
+    void encode() {
+        // given
+        String plainPassword = "password";
+
+        // when
+        String actual = sCryptExample.encode(plainPassword);
+
+        // then
+        assertThat(actual).hasSize(140);
+        assertThat(actual).startsWith("$e0801");
+    }
+}