我总是使用BouncyCastle
我还使用流框架而不是您描述的 for 循环:它处理提出的问题。大多数情况下我使用它,因为当涉及到密码学(和线程)时,我很少相信我自己的代码,我相信活着的人吃和呼吸它。这是我想要“gash”加密时使用的代码。即我没有特定的威胁模型,只是想要一些“有点安全”的东西。
密钥的十六进制编码使它们更容易操作/存储等等。我使用“makeKey”来......好吧......制作一个密钥,然后我可以在加密和解密方法中使用该密钥。您显然可以返回使用byte[]
而不是使用十六进制字符串作为键。
private static boolean initialised;
private static void init() {
if (initialised)
return;
Security.addProvider(new BouncyCastleProvider());
initialised = true;
}
public static String makeKey() {
init();
KeyGenerator generator = KeyGenerator.getInstance(algorithm, provider);
generator.init(keySize);
Key key = generator.generateKey();
byte[] encoded = key.getEncoded();
return Strings.toHex(encoded);
}
public static String aesDecrypt(String hexKey, String hexCoded) {
init();
SecretKeySpec key = new SecretKeySpec(Strings.fromHex(hexKey), algorithm);
Cipher cipher = Cipher.getInstance(algorithm + "/ECB/PKCS5Padding", provider);
cipher.init(Cipher.DECRYPT_MODE, key);
byte[] codedBytes = Strings.fromHex(hexCoded);
CipherInputStream inputStream = new CipherInputStream(new ByteArrayInputStream(codedBytes), cipher);
byte[] bytes = getBytes(inputStream, 256);
String result = new String(bytes, "UTF-8");
return result;
}
public static String aesEncrypt(String hexKey, String input) {
init();
SecretKeySpec key = new SecretKeySpec(Strings.fromHex(hexKey), algorithm);
Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5Padding", "BC");
cipher.init(Cipher.ENCRYPT_MODE, key);
ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream(input.length());
CipherOutputStream outputStream = new CipherOutputStream(byteArrayOutputStream, cipher);
setText(outputStream, input);
byte[] outputBytes = byteArrayOutputStream.toByteArray();
String output = new String(Strings.toHex(outputBytes));
return output;
}
public static void setText(OutputStream outputStream, String text, String encoding) {
try {
outputStream.write(text.getBytes(encoding));
outputStream.flush();
} finally {
outputStream.close();
}
}
public static byte[] getBytes(InputStream inputStream, int bufferSize) {
try {
List<ByteArrayAndLength> list = Lists.newList();
while (true) {
byte[] buffer = new byte[bufferSize];
int count = inputStream.read(buffer);
if (count == -1) {
byte[] result = new byte[ByteArrayAndLength.length(list)];
int index = 0;
for (ByteArrayAndLength byteArrayAndLength : list) {
System.arraycopy(byteArrayAndLength.bytes, 0, result, index, byteArrayAndLength.length);
index += byteArrayAndLength.length;
}
assert index == result.length;
return result;
}
list.add(new ByteArrayAndLength(buffer, count));
}
} finally {
inputStream.close();
}
}
static class ByteArrayAndLength {
byte[] bytes;
int length;
public ByteArrayAndLength(byte[] bytes, int length) {
super();
this.bytes = bytes;
this.length = length;
}
static int length(List<ByteArrayAndLength> list) {
int result = 0;
for (ByteArrayAndLength byteArrayAndLength : list) {
result += byteArrayAndLength.length;
}
return result;
}
}
我已经删除了一些异常捕获以减少代码的大小,并将Strings.fromHex
字符串转换回byte[]