java: Add AesException

java/src/main/java/dev/medzik/libcrypto/Aes.java

@@ -1,15 +1,9 @@
 package dev.medzik.libcrypto;
 
-import javax.crypto.BadPaddingException;
 import javax.crypto.Cipher;
-import javax.crypto.IllegalBlockSizeException;
-import javax.crypto.NoSuchPaddingException;
 import javax.crypto.spec.GCMParameterSpec;
 import javax.crypto.spec.IvParameterSpec;
 import javax.crypto.spec.SecretKeySpec;
-import java.security.InvalidAlgorithmParameterException;
-import java.security.InvalidKeyException;
-import java.security.NoSuchAlgorithmException;
 import java.security.spec.AlgorithmParameterSpec;
 
 public final class Aes {
@@ -20,12 +14,14 @@ public final class Aes {
 
     /**
      * Encrypts the given clear bytes using AES with the given key and random IV.
+     *
      * @param type AES type to use
      * @param key secret key to use for encryption
      * @param clearBytes clear bytes to encrypt (UTF-8)
      * @return Encrypted cipher (hex encoded)
+     * @throws AesException if encryption fails
      */
-    public static String encrypt(AesType type, byte[] key, byte[] clearBytes) throws InvalidKeyException, IllegalBlockSizeException, BadPaddingException {
+    public static String encrypt(AesType type, byte[] key, byte[] clearBytes) throws AesException {
         // generate random IV
         byte[] iv = Random.randBytes(type.getIvLength());
 
@@ -37,28 +33,32 @@ public static String encrypt(AesType type, byte[] key, byte[] clearBytes) throws
         try {
             cipher = Cipher.getInstance(type.getMode());
             cipher.init(Cipher.ENCRYPT_MODE, secretKey, parameterSpec);
-        } catch (InvalidAlgorithmParameterException |
-                 NoSuchPaddingException |
-                 NoSuchAlgorithmException e) {
-            // never happen
-            throw new RuntimeException(e);
+        } catch (Exception e) {
+            throw new AesException("Failed to init cipher", e);
         }
 
         // encrypt
-        byte[] cipherBytes = cipher.doFinal(clearBytes);
+        byte[] cipherBytes;
+        try {
+            cipherBytes = cipher.doFinal(clearBytes);
+        } catch (Exception e) {
+            throw new AesException("Failed to finalize encryption", e);
+        }
 
         // return IV + cipher text as hex string
         return Hex.encode(iv) + Hex.encode(cipherBytes);
     }
 
     /**
      * Decrypts the given cipher text using AES with the given key.
+     *
      * @param type AES type to use
      * @param key secret key to use for decryption
      * @param cipherText cipher text to decrypt (hex encoded)
      * @return Decrypted bytes
+     * @throws AesException if decryption fails
      */
-    public static byte[] decrypt(AesType type, byte[] key, String cipherText) throws InvalidKeyException, IllegalBlockSizeException, BadPaddingException {
+    public static byte[] decrypt(AesType type, byte[] key, String cipherText) throws AesException {
         // get IV length in hex string
         int ivLength = type.getIvLength() * 2;
 
@@ -74,15 +74,16 @@ public static byte[] decrypt(AesType type, byte[] key, String cipherText) throws
         try {
             cipher = Cipher.getInstance(type.getMode());
             cipher.init(Cipher.DECRYPT_MODE, secretKey, parameterSpec);
-        } catch (InvalidAlgorithmParameterException |
-                 NoSuchPaddingException |
-                 NoSuchAlgorithmException e) {
-            // never happen
-            throw new RuntimeException(e);
+        } catch (Exception e) {
+            throw new AesException("Failed to init cipher", e);
         }
 
         // decrypt
-        return cipher.doFinal(cipherBytes);
+        try {
+            return cipher.doFinal(cipherBytes);
+        } catch (Exception e) {
+            throw new AesException("Failed to finalize decryption", e);
+        }
     }
 
     private static AlgorithmParameterSpec getParameterSpec(AesType type, byte[] iv) {

java/src/main/java/dev/medzik/libcrypto/AesException.java

@@ -0,0 +1,7 @@
+package dev.medzik.libcrypto;
+
+public class AesException extends Exception {
+    public AesException(String message, Exception cause) {
+        super(message, cause);
+    }
+}

java/src/main/java/dev/medzik/libcrypto/Argon2EncodingUtils.java

@@ -11,6 +11,7 @@ public final class Argon2EncodingUtils {
 
     /**
      * Encodes the given hash and parameters to a string.
+     *
      * @param hash hash to encode
      * @return encoded hash in argon2 format
      */
@@ -42,6 +43,7 @@ public static String encode(Argon2Hash hash) {
 
     /**
      * Decodes the given Argon2 encoded hash.
+     *
      * @param encodedHash encoded hash in argon2 format
      * @return {@link Argon2Hash}
      */

java/src/main/java/dev/medzik/libcrypto/Argon2Hash.java

@@ -1,8 +1,6 @@
 package dev.medzik.libcrypto;
 
-/**
- * Object representation of argon2 hash.
- */
+/** Object representation of argon2 hash. */
 public final class Argon2Hash {
     private final Argon2Type type;
     private final int version;

java/src/main/java/dev/medzik/libcrypto/Argon2Type.java

@@ -15,8 +15,8 @@ public Argon2 toPassword4jType() {
                 return Argon2.I;
             case ID:
                 return Argon2.ID;
-            default:
-                throw new IllegalStateException("Unexpected value: " + this);
         }
+        // never happens
+        return null;
     }
 }

java/src/main/java/dev/medzik/libcrypto/Hex.java

@@ -47,7 +47,10 @@ public static String encode(byte[] bytes) {
         return result.toString();
     }
 
-    /** Decodes a hex string to a byte array. */
+    /**
+     * Decodes a hex string to a byte array.
+     * @throws IllegalArgumentException if the input is not hexadecimal
+     */
     public static byte[] decode(String hex) {
         if (hex.length() % 2 != 0) {
             throw new IllegalArgumentException("Expected a string of even length");

java/src/main/java/dev/medzik/libcrypto/Random.java

@@ -3,13 +3,10 @@
 import java.security.SecureRandom;
 
 public final class Random {
-    /**
-     * Generate a random byte array.
-     * @param size length of salt slice in bytes
-     */
-    public static byte[] randBytes(int size) {
+    /** Generate a random byte array. */
+    public static byte[] randBytes(int length) {
         SecureRandom rd = new SecureRandom();
-        byte[] salt = new byte[size];
+        byte[] salt = new byte[length];
         rd.nextBytes(salt);
         return salt;
     }

java/src/main/java/dev/medzik/libcrypto/X25519.java

@@ -62,8 +62,7 @@ public static byte[] generatePrivateKey() {
      * @return 32-byte shared secret
      * @throws InvalidKeyException when {@code ourPrivate} is not 32-byte or {@code theirPublic} is invalid.
      */
-    public static byte[] computeSharedSecret(byte[] ourPrivate, byte[] theirPublic)
-            throws InvalidKeyException {
+    public static byte[] computeSharedSecret(byte[] ourPrivate, byte[] theirPublic) throws InvalidKeyException {
         if (ourPrivate.length != Field25519.FIELD_LEN) {
             throw new InvalidKeyException("Private key must have 32 bytes.");
         }

java/src/test/java/dev/medzik/libcrypto/AesTests.java

@@ -2,15 +2,11 @@
 
 import org.junit.jupiter.api.Test;
 
-import javax.crypto.BadPaddingException;
-import javax.crypto.IllegalBlockSizeException;
-import java.security.InvalidKeyException;
-
 import static org.junit.jupiter.api.Assertions.assertEquals;
 
 public final class AesTests {
     @Test
-    public void testCBCEncryptAndDecrypt() throws IllegalBlockSizeException, BadPaddingException, InvalidKeyException {
+    public void testCBCEncryptAndDecrypt() throws AesException {
         byte[] secretKey = Hex.decode("82fd4cefd6efde36171900b469bae4e06863cb70f80b4e216e44eeb0cf30460b");
 
         String input = "Hello World!";
@@ -21,7 +17,7 @@ public void testCBCEncryptAndDecrypt() throws IllegalBlockSizeException, BadPadd
     }
 
     @Test
-    public void testCBCDecrypt() throws IllegalBlockSizeException, BadPaddingException, InvalidKeyException {
+    public void testCBCDecrypt() throws AesException {
         byte[] secretKey = Hex.decode("82fd4cefd6efde36171900b469bae4e06863cb70f80b4e216e44eeb0cf30460b");
 
         String cipherText = "ae77d812f4494a766a94b5dff8e7aa3c8408544b9fd30cd13b886cc5dd1b190e";
@@ -31,7 +27,7 @@ public void testCBCDecrypt() throws IllegalBlockSizeException, BadPaddingExcepti
     }
 
     @Test
-    public void testGCMEncryptAndDecrypt() throws IllegalBlockSizeException, BadPaddingException, InvalidKeyException {
+    public void testGCMEncryptAndDecrypt() throws AesException {
         byte[] secretKey = Hex.decode("82fd4cefd6efde36171900b469bae4e06863cb70f80b4e216e44eeb0cf30460b");
 
         String input = "Hello World!";
@@ -42,7 +38,7 @@ public void testGCMEncryptAndDecrypt() throws IllegalBlockSizeException, BadPadd
     }
 
     @Test
-    void testGCMDecrypt() throws IllegalBlockSizeException, BadPaddingException, InvalidKeyException {
+    void testGCMDecrypt() throws AesException {
         byte[] secretKey = Hex.decode("82fd4cefd6efde36171900b469bae4e06863cb70f80b4e216e44eeb0cf30460b");
 
         String cipherText = "0996c65a72a60e748415dc6d32da1d4dcb65f41c71d4bec9554424218839b5d4b9d9195e5eea9d";

java/src/test/java/dev/medzik/libcrypto/ReadmeTests.java

@@ -2,16 +2,14 @@
 
 import org.junit.jupiter.api.Test;
 
-import javax.crypto.BadPaddingException;
-import javax.crypto.IllegalBlockSizeException;
 import java.security.InvalidKeyException;
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
 public final class ReadmeTests {
     @Test
-    public void testAesGcmEncryptDecryption() throws IllegalBlockSizeException, BadPaddingException, InvalidKeyException {
+    public void testAesGcmEncryptDecryption() throws AesException {
         String clearText = "hello world";
         // Key used for encryption (for example, argon2 hash in hex string)
         String secretKey = "82fd4cefd6efde36171900b469bae4e06863cb70f80b4e216e44eeb0cf30460b";
@@ -47,7 +45,7 @@ public void testArgon2Hash() {
     }
 
     @Test
-    public void testX25519ExchangeKeys() throws InvalidKeyException, IllegalBlockSizeException, BadPaddingException {
+    public void testX25519ExchangeKeys() throws InvalidKeyException, AesException {
         // Generate private key for Bob
         byte[] bobPrivateKey = X25519.generatePrivateKey();
         byte[] bobPublicKey = X25519.publicFromPrivate(bobPrivateKey);