Merge pull request #10234 from hmdrzsharifi/BAEL-4460

BAEL-4460: Java AES encryption and decryption

core-java-modules/core-java-security-2/pom.xml

@@ -53,7 +53,7 @@
         <commons-codec.version>1.11</commons-codec.version>
 
         <!-- testing -->
-        <assertj-core.version>3.10.0</assertj-core.version>
+        <assertj-core.version>3.18.0</assertj-core.version>
         <jaxb-api.version>2.3.1</jaxb-api.version>
     </properties>
 

core-java-modules/core-java-security-2/src/main/java/com/baeldung/aes/AESUtil.java

@@ -0,0 +1,156 @@
+package com.baeldung.aes;
+
+import javax.crypto.Cipher;
+import javax.crypto.IllegalBlockSizeException;
+import javax.crypto.NoSuchPaddingException;
+import javax.crypto.SecretKey;
+import javax.crypto.BadPaddingException;
+import javax.crypto.KeyGenerator;
+import javax.crypto.SecretKeyFactory;
+import javax.crypto.SealedObject;
+import javax.crypto.spec.IvParameterSpec;
+import javax.crypto.spec.PBEKeySpec;
+import javax.crypto.spec.SecretKeySpec;
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.Serializable;
+import java.security.InvalidAlgorithmParameterException;
+import java.security.InvalidKeyException;
+import java.security.NoSuchAlgorithmException;
+import java.security.SecureRandom;
+import java.security.spec.InvalidKeySpecException;
+import java.security.spec.KeySpec;
+import java.util.Base64;
+
+public class AESUtil {
+
+    public static String encrypt(String algorithm, String input, SecretKey key, IvParameterSpec iv)
+        throws NoSuchPaddingException, NoSuchAlgorithmException, InvalidAlgorithmParameterException,
+        InvalidKeyException, BadPaddingException, IllegalBlockSizeException {
+        Cipher cipher = Cipher.getInstance(algorithm);
+        cipher.init(Cipher.ENCRYPT_MODE, key, iv);
+        byte[] cipherText = cipher.doFinal(input.getBytes());
+        return Base64.getEncoder()
+            .encodeToString(cipherText);
+    }
+
+    public static String decrypt(String algorithm, String cipherText, SecretKey key, IvParameterSpec iv)
+        throws NoSuchPaddingException, NoSuchAlgorithmException, InvalidAlgorithmParameterException,
+        InvalidKeyException, BadPaddingException, IllegalBlockSizeException {
+        Cipher cipher = Cipher.getInstance(algorithm);
+        cipher.init(Cipher.DECRYPT_MODE, key, iv);
+        byte[] plainText = cipher.doFinal(Base64.getDecoder()
+            .decode(cipherText));
+        return new String(plainText);
+    }
+
+    public static SecretKey generateKey(int n) throws NoSuchAlgorithmException {
+        KeyGenerator keyGenerator = KeyGenerator.getInstance("AES");
+        keyGenerator.init(n);
+        SecretKey key = keyGenerator.generateKey();
+        return key;
+    }
+
+    public static SecretKey getKeyFromPassword(String password, String salt)
+        throws NoSuchAlgorithmException, InvalidKeySpecException {
+        SecretKeyFactory factory = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA256");
+        KeySpec spec = new PBEKeySpec(password.toCharArray(), salt.getBytes(), 65536, 256);
+        SecretKey secret = new SecretKeySpec(factory.generateSecret(spec)
+            .getEncoded(), "AES");
+        return secret;
+    }
+
+    public static IvParameterSpec generateIv() {
+        byte[] iv = new byte[16];
+        new SecureRandom().nextBytes(iv);
+        return new IvParameterSpec(iv);
+    }
+
+    public static void encryptFile(String algorithm, SecretKey key, IvParameterSpec iv,
+        File inputFile, File outputFile) throws IOException, NoSuchPaddingException,
+        NoSuchAlgorithmException, InvalidAlgorithmParameterException, InvalidKeyException,
+        BadPaddingException, IllegalBlockSizeException {
+        Cipher cipher = Cipher.getInstance(algorithm);
+        cipher.init(Cipher.ENCRYPT_MODE, key, iv);
+        FileInputStream inputStream = new FileInputStream(inputFile);
+        FileOutputStream outputStream = new FileOutputStream(outputFile);
+        byte[] buffer = new byte[64];
+        int bytesRead;
+        while ((bytesRead = inputStream.read(buffer)) != -1) {
+            byte[] output = cipher.update(buffer, 0, bytesRead);
+            if (output != null) {
+                outputStream.write(output);
+            }
+        }
+        byte[] outputBytes = cipher.doFinal();
+        if (outputBytes != null) {
+            outputStream.write(outputBytes);
+        }
+        inputStream.close();
+        outputStream.close();
+    }
+
+    public static void decryptFile(String algorithm, SecretKey key, IvParameterSpec iv,
+        File encryptedFile, File decryptedFile) throws IOException, NoSuchPaddingException,
+        NoSuchAlgorithmException, InvalidAlgorithmParameterException, InvalidKeyException,
+        BadPaddingException, IllegalBlockSizeException {
+        Cipher cipher = Cipher.getInstance(algorithm);
+        cipher.init(Cipher.DECRYPT_MODE, key, iv);
+        FileInputStream inputStream = new FileInputStream(encryptedFile);
+        FileOutputStream outputStream = new FileOutputStream(decryptedFile);
+        byte[] buffer = new byte[64];
+        int bytesRead;
+        while ((bytesRead = inputStream.read(buffer)) != -1) {
+            byte[] output = cipher.update(buffer, 0, bytesRead);
+            if (output != null) {
+                outputStream.write(output);
+            }
+        }
+        byte[] output = cipher.doFinal();
+        if (output != null) {
+            outputStream.write(output);
+        }
+        inputStream.close();
+        outputStream.close();
+    }
+
+    public static SealedObject encryptObject(String algorithm, Serializable object, SecretKey key,
+        IvParameterSpec iv) throws NoSuchPaddingException, NoSuchAlgorithmException,
+        InvalidAlgorithmParameterException, InvalidKeyException, IOException, IllegalBlockSizeException {
+        Cipher cipher = Cipher.getInstance(algorithm);
+        cipher.init(Cipher.ENCRYPT_MODE, key, iv);
+        SealedObject sealedObject = new SealedObject(object, cipher);
+        return sealedObject;
+    }
+
+    public static Serializable decryptObject(String algorithm, SealedObject sealedObject, SecretKey key,
+        IvParameterSpec iv) throws NoSuchPaddingException, NoSuchAlgorithmException,
+        InvalidAlgorithmParameterException, InvalidKeyException, ClassNotFoundException,
+        BadPaddingException, IllegalBlockSizeException, IOException {
+        Cipher cipher = Cipher.getInstance(algorithm);
+        cipher.init(Cipher.DECRYPT_MODE, key, iv);
+        Serializable unsealObject = (Serializable) sealedObject.getObject(cipher);
+        return unsealObject;
+    }
+
+    public static String encryptPasswordBased(String plainText, SecretKey key, IvParameterSpec iv)
+        throws NoSuchPaddingException, NoSuchAlgorithmException, InvalidAlgorithmParameterException,
+        InvalidKeyException, BadPaddingException, IllegalBlockSizeException {
+        Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
+        cipher.init(Cipher.ENCRYPT_MODE, key, iv);
+        return Base64.getEncoder()
+            .encodeToString(cipher.doFinal(plainText.getBytes()));
+    }
+
+    public static String decryptPasswordBased(String cipherText, SecretKey key, IvParameterSpec iv)
+        throws NoSuchPaddingException, NoSuchAlgorithmException, InvalidAlgorithmParameterException,
+        InvalidKeyException, BadPaddingException, IllegalBlockSizeException {
+        Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5PADDING");
+        cipher.init(Cipher.DECRYPT_MODE, key, iv);
+        return new String(cipher.doFinal(Base64.getDecoder()
+            .decode(cipherText)));
+    }
+
+}

core-java-modules/core-java-security-2/src/main/java/com/baeldung/aes/Student.java

@@ -0,0 +1,40 @@
+package com.baeldung.aes;
+
+import java.io.Serializable;
+import java.util.Objects;
+
+public class Student implements Serializable {
+    private String name;
+    private int age;
+
+    public Student(String name, int age) {
+        this.name = name;
+        this.age = age;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public int getAge() {
+        return age;
+    }
+
+    public void setAge(int age) {
+        this.age = age;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o)
+            return true;
+        if (o == null || getClass() != o.getClass())
+            return false;
+        Student student = (Student) o;
+        return age == student.age && Objects.equals(name, student.name);
+    }
+}

core-java-modules/core-java-security-2/src/test/java/com/baeldung/aes/AESUtilUnitTest.java

@@ -0,0 +1,101 @@
+package com.baeldung.aes;
+
+import org.assertj.core.api.WithAssertions;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+
+import javax.crypto.SealedObject;
+import javax.crypto.SecretKey;
+import javax.crypto.spec.IvParameterSpec;
+import javax.crypto.BadPaddingException;
+import javax.crypto.IllegalBlockSizeException;
+import javax.crypto.NoSuchPaddingException;
+import java.io.File;
+import java.io.IOException;
+import java.nio.file.Paths;
+import java.security.InvalidAlgorithmParameterException;
+import java.security.InvalidKeyException;
+import java.security.NoSuchAlgorithmException;
+import java.security.spec.InvalidKeySpecException;
+
+class AESUtilUnitTest implements WithAssertions {
+
+    @Test
+    void givenString_whenEncrypt_thenSuccess()
+        throws NoSuchAlgorithmException, IllegalBlockSizeException, InvalidKeyException,
+        BadPaddingException, InvalidAlgorithmParameterException, NoSuchPaddingException {
+        // given
+        String input = "baeldung";
+        SecretKey key = AESUtil.generateKey(128);
+        IvParameterSpec ivParameterSpec = AESUtil.generateIv();
+        String algorithm = "AES/CBC/PKCS5Padding";
+
+        // when
+        String cipherText = AESUtil.encrypt(algorithm, input, key, ivParameterSpec);
+        String plainText = AESUtil.decrypt(algorithm, cipherText, key, ivParameterSpec);
+
+        // then
+        Assertions.assertEquals(input, plainText);
+    }
+
+    @Test
+    void givenFile_whenEncrypt_thenSuccess()
+        throws NoSuchAlgorithmException, IOException, IllegalBlockSizeException, InvalidKeyException,
+        BadPaddingException, InvalidAlgorithmParameterException, NoSuchPaddingException {
+        // given
+        SecretKey key = AESUtil.generateKey(128);
+        String algorithm = "AES/CBC/PKCS5Padding";
+        IvParameterSpec ivParameterSpec = AESUtil.generateIv();
+        File inputFile = Paths.get("src/test/resources/baeldung.txt")
+            .toFile();
+        File encryptedFile = new File("classpath:baeldung.encrypted");
+        File decryptedFile = new File("document.decrypted");
+
+        // when
+        AESUtil.encryptFile(algorithm, key, ivParameterSpec, inputFile, encryptedFile);
+        AESUtil.decryptFile(algorithm, key, ivParameterSpec, encryptedFile, decryptedFile);
+
+        // then
+        assertThat(inputFile).hasSameTextualContentAs(decryptedFile);
+        encryptedFile.delete();
+        decryptedFile.delete();
+    }
+
+    @Test
+    void givenObject_whenEncrypt_thenSuccess()
+        throws NoSuchAlgorithmException, IllegalBlockSizeException, InvalidKeyException,
+        InvalidAlgorithmParameterException, NoSuchPaddingException, IOException, BadPaddingException,
+        ClassNotFoundException {
+        // given
+        Student student = new Student("Baeldung", 20);
+        SecretKey key = AESUtil.generateKey(128);
+        IvParameterSpec ivParameterSpec = AESUtil.generateIv();
+        String algorithm = "AES/CBC/PKCS5Padding";
+
+        // when
+        SealedObject sealedObject = AESUtil.encryptObject(algorithm, student, key, ivParameterSpec);
+        Student object = (Student) AESUtil.decryptObject(algorithm, sealedObject, key, ivParameterSpec);
+
+        // then
+        assertThat(student).isEqualTo(object);
+    }
+
+    @Test
+    void givenPassword_whenEncrypt_thenSuccess()
+        throws InvalidKeySpecException, NoSuchAlgorithmException, IllegalBlockSizeException,
+        InvalidKeyException, BadPaddingException, InvalidAlgorithmParameterException, NoSuchPaddingException {
+        // given
+        String plainText = "www.baeldung.com";
+        String password = "baeldung";
+        String salt = "12345678";
+        IvParameterSpec ivParameterSpec = AESUtil.generateIv();
+        SecretKey key = AESUtil.getKeyFromPassword(password, salt);
+
+        // when
+        String cipherText = AESUtil.encryptPasswordBased(plainText, key, ivParameterSpec);
+        String decryptedCipherText = AESUtil.decryptPasswordBased(cipherText, key, ivParameterSpec);
+
+        // then
+        Assertions.assertEquals(plainText, decryptedCipherText);
+    }
+}

core-java-modules/core-java-security-2/src/test/resources/baeldung.txt

@@ -0,0 +1,2 @@
+Hello Baeldung
+This is AES file encryption sample