From eef1459f0b56bb53b8595ec7cf03121d559b7a1d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Dominique=20Eifl=C3=A4nder?=
 <deiflaender@dominiques-mbp.speedport.ip>
Date: Thu, 14 Oct 2021 12:42:32 +0200
Subject: [PATCH] RED-2252: Use compliant encryption algorithm
 AES/GCM/NoPadding

---
 .../service/EncryptionDecryptionService.java  | 98 ++++++++++++++-----
 1 file changed, 72 insertions(+), 26 deletions(-)

diff --git a/persistence-service-v1/persistence-service-processor-v1/src/main/java/com/iqser/red/service/persistence/management/v1/processor/service/EncryptionDecryptionService.java b/persistence-service-v1/persistence-service-processor-v1/src/main/java/com/iqser/red/service/persistence/management/v1/processor/service/EncryptionDecryptionService.java
index be071f77f..88913d646 100644
--- a/persistence-service-v1/persistence-service-processor-v1/src/main/java/com/iqser/red/service/persistence/management/v1/processor/service/EncryptionDecryptionService.java
+++ b/persistence-service-v1/persistence-service-processor-v1/src/main/java/com/iqser/red/service/persistence/management/v1/processor/service/EncryptionDecryptionService.java
@@ -1,61 +1,107 @@
 package com.iqser.red.service.persistence.management.v1.processor.service;
 
 import lombok.SneakyThrows;
+
 import org.springframework.beans.factory.annotation.Value;
 import org.springframework.stereotype.Service;
 
 import javax.annotation.PostConstruct;
 import javax.crypto.Cipher;
+import javax.crypto.SecretKey;
+import javax.crypto.SecretKeyFactory;
+import javax.crypto.spec.GCMParameterSpec;
+import javax.crypto.spec.PBEKeySpec;
 import javax.crypto.spec.SecretKeySpec;
+
+import java.nio.ByteBuffer;
 import java.nio.charset.StandardCharsets;
 import java.security.MessageDigest;
+import java.security.SecureRandom;
+import java.security.spec.KeySpec;
 import java.util.Arrays;
 import java.util.Base64;
 
 @Service
 public class EncryptionDecryptionService {
 
-    @Value("${configuration-service.crypto.key:redaction}")
+    @Value("${persistence-service.crypto.key:redaction}")
     private String key;
-    private SecretKeySpec secretKey;
+
+    private SecretKey secretKey;
+    private byte[] iv;
+
 
     @SneakyThrows
     @PostConstruct
     protected void postConstruct() {
-        byte[] keyBytes = key.getBytes(StandardCharsets.UTF_8);
-        var sha = MessageDigest.getInstance("SHA-1");
-        keyBytes = sha.digest(keyBytes);
-        keyBytes = Arrays.copyOf(keyBytes, 16);
-        secretKey = new SecretKeySpec(keyBytes, "AES");
+
+        SecureRandom secureRandom = new SecureRandom();
+        iv = new byte[12];
+        secureRandom.nextBytes(iv);
+        secretKey = generateSecretKey(key, iv);
     }
 
+
     @SneakyThrows
     public String encrypt(String strToEncrypt) {
-        Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5Padding");
-        cipher.init(Cipher.ENCRYPT_MODE, secretKey);
-        return Base64.getEncoder().encodeToString(cipher.doFinal(strToEncrypt.getBytes(StandardCharsets.UTF_8)));
+
+        return Base64.getEncoder().encodeToString(encrypt(strToEncrypt.getBytes()));
     }
 
-    @SneakyThrows
-    public byte[] encrypt(byte[] bytes) {
-        Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5Padding");
-        cipher.init(Cipher.ENCRYPT_MODE, secretKey);
-        return cipher.doFinal(bytes);
-    }
-
-    @SneakyThrows
-    public byte[] decrypt(byte[] bytes) {
-        Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5Padding");
-        cipher.init(Cipher.ENCRYPT_MODE, secretKey);
-        return cipher.doFinal(bytes);
-    }
 
     @SneakyThrows
     public String decrypt(String strToDecrypt) {
-        Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5PADDING");
-        cipher.init(Cipher.DECRYPT_MODE, secretKey);
-        return new String(cipher.doFinal(Base64.getDecoder().decode(strToDecrypt)), StandardCharsets.UTF_8);
+
+        byte[] bytes = Base64.getDecoder().decode(strToDecrypt);
+        return new String(decrypt(bytes), StandardCharsets.UTF_8);
     }
 
 
+    @SneakyThrows
+    public byte[] encrypt(byte[] data) {
+
+        Cipher cipher = Cipher.getInstance("AES/GCM/NoPadding");
+        GCMParameterSpec parameterSpec = new GCMParameterSpec(128, iv);
+        cipher.init(Cipher.ENCRYPT_MODE, secretKey, parameterSpec);
+        byte[] encryptedData = cipher.doFinal(data);
+        ByteBuffer byteBuffer = ByteBuffer.allocate(4 + iv.length + encryptedData.length);
+        byteBuffer.putInt(iv.length);
+        byteBuffer.put(iv);
+        byteBuffer.put(encryptedData);
+        return byteBuffer.array();
+    }
+
+
+    @SneakyThrows
+    public byte[] decrypt(byte[] encryptedData) {
+
+        ByteBuffer byteBuffer = ByteBuffer.wrap(encryptedData);
+        int noonceSize = byteBuffer.getInt();
+        if (noonceSize < 12 || noonceSize >= 16) {
+            throw new IllegalArgumentException("Nonce size is incorrect. Make sure that the incoming data is an AES encrypted file.");
+        }
+        byte[] iv = new byte[noonceSize];
+        byteBuffer.get(iv);
+
+        SecretKey secretKey = generateSecretKey(key, iv);
+
+        byte[] cipherBytes = new byte[byteBuffer.remaining()];
+        byteBuffer.get(cipherBytes);
+
+        Cipher cipher = Cipher.getInstance("AES/GCM/NoPadding");
+        GCMParameterSpec parameterSpec = new GCMParameterSpec(128, iv);
+        cipher.init(Cipher.DECRYPT_MODE, secretKey, parameterSpec);
+        return cipher.doFinal(cipherBytes);
+    }
+
+
+    @SneakyThrows
+    public SecretKey generateSecretKey(String password, byte[] iv) {
+
+        KeySpec spec = new PBEKeySpec(password.toCharArray(), iv, 65536, 128); // AES-128
+        SecretKeyFactory secretKeyFactory = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA1");
+        byte[] key = secretKeyFactory.generateSecret(spec).getEncoded();
+        return new SecretKeySpec(key, "AES");
+    }
+
 }