# Symmetric Ciphers ## Cipher ```java Cipher cipher( byte[] key, String keyAlgorithm, String cipherAlgorithm, Mode mode ); ``` Returns a symmetric cipher for the given key, key algorithm, cipher algorithm and mode. ### Usage Example ```java Random rng = new SecureRandom(); byte[] iv = new byte[8]; rng.nextBytes(iv); byte[] key = symmetricKey("DESede"); Cipher encrypter = Bruce.cipher(key, "DESede", "DESede/CBC/PKCS5Padding", ENCRYPT); Cipher decrypter = Bruce.cipher(key, "DESede", "DESede/CBC/PKCS5Padding", DECRYPT); byte[] clearText = "Hi there".getBytes(UTF_8); byte[] cypherText = encrypter.encrypt(iv, clearText); byte[] decryptedText = decrypter.encrypt(iv, cypherText); assertArrayEquals(clearText, decryptedText); ``` ## Cipher By Key ```java CipherByKey cipher( String keyAlgorithm, String cipherAlgorithm, Mode mode ); ``` Returns a cipher where the key can be passed at runtime through the returned interface. ### Usage Example ```java Random rng = new SecureRandom(); byte[] iv = new byte[8]; // initialization vector rng.nextBytes(iv); byte[] key = symmetricKey("DESede"); CipherByKey encrypter = cipher("DESede", "DESede/CBC/PKCS5Padding", ENCRYPT); CipherByKey decrypter = cipher("DESede", "DESede/CBC/PKCS5Padding", DECRYPT); byte[] plainText = "Hi there".getBytes(UTF_8); byte[] cypherText = encrypter.encrypt(key, iv, plainText); byte[] decryptedText = decrypter.encrypt(key, iv, cypherText); assertArrayEquals(plainText, decryptedText); ``` ## Encoding Cipher ```julia EncodingCipher cipher( String key, String keyAlgorithm, String cipherAlgorithm, Mode mode, Charset charset, Encoding encoding ); ``` Returns an encoding cipher. The key must also be encoded with the specified encoding. The character set refers to the plain text message string encoding. ### Usage Example ```java Random rng = new SecureRandom(); byte[] ivBA = new byte[8]; // initialization vector byte array rng.nextBytes(ivBA); String iv = Base64.getEncoder().encodeToString(ivBA); String key = symmetricKey("DESede", BASE64); EncodingCipher encrypter = cipher(key, "DESede", "DESede/CBC/PKCS5Padding", ENCRYPT, UTF_8, BASE64); EncodingCipher decrypter = cipher(key, "DESede", "DESede/CBC/PKCS5Padding", DECRYPT, UTF_8, BASE64); String plainText = "Hi there"; String cypherText = encrypter.encrypt(iv, plainText); String decryptedText = decrypter.encrypt(iv, cypherText); assertEquals(plainText, decryptedText); ``` ## Encoding Cipher By Key ```java EncodingCipherByKey cipherByKey( String keyAlgorithm, String cipherAlgorithm, Mode mode, Charset charset ); ``` Same as [encoding cipher](symmetric-ciphers.md#encoding-cipher) but allows you to provide the keys at runtime. ### Usage Example ```java Random rng = new SecureRandom(); byte[] ivBA = new byte[8]; // initialization vector byte array rng.nextBytes(ivBA); String iv = Base64.getEncoder().encodeToString(ivBA); String key = symmetricKey("DESede", BASE64); EncodingCipherByKey encrypter = cipherByKey("DESede", "DESede/CBC/PKCS5Padding", ENCRYPT, UTF_8); EncodingCipherByKey decrypter = cipherByKey("DESede", "DESede/CBC/PKCS5Padding", DECRYPT, UTF_8); String clearText = "Hi there"; String cypherText = encrypter.encrypt(key, iv, clearText, BASE64); String decryptedText = decrypter.encrypt(key, iv, cypherText, BASE64); assertEquals(clearText, decryptedText); ```