java 下的 AES org.bouncycastle.crypto 包加密解密算法示例

算法模式：CBC
填充模式：PKCS5
初始化向量IV：0x31, 0x37, 0x36, 0x35, 0x34, 0x33, 0x32, 0x31, 0x38, 0x27, 0x36, 0x35, 0x33, 0x23, 0x32, 0x33，IV值一定是128位的(16字节).
为提高加密性能，建议使用Bouncy Castle Inc.公司提供的算法包，以下样例中使用的就是该公司的算法包。其运算速度是jdk自带的10倍以上。

包下载链接，按照自己的jdk版本选择算法包：http://www.bouncycastle.org/latest_releases.html

主要代码：

private static final byte[] INIT_VECTOR = { 0x31, 0x37, 0x36, 0x35, 
                                       0x34, 0x33, 0x32, 0x31, 
                                       0x38, 0x27, 0x36, 0x35, 
                                       0x33, 0x23, 0x32, 0x33 };




public static String encrypt(String content, String apiKey)
throws Exception {
if (apiKey == null) {
throw new IllegalArgumentException("Key cannot be null!");
}
String encrypted = null;
byte[] keyBytes = apiKey.getBytes();
if (keyBytes.length != 32 && keyBytes.length != 24
&& keyBytes.length != 16) {
throw new IllegalArgumentException(
"Key length must be   128/192/256 bits!");
}
byte[] encryptedBytes = null;
encryptedBytes = encrypt(content.getBytes(), keyBytes, INIT_VECTOR);
encrypted = new String(Hex.encode(encryptedBytes));
return encrypted;
}


public static String decrypt(String content, String apiKey)
throws Exception {
if (apiKey == null) {
throw new IllegalArgumentException("Key cannot be null!");
}
String decrypted = null;
byte[] encryptedContent = Hex.decode(content);
byte[] keyBytes = apiKey.getBytes();
byte[] decryptedBytes = null;
if (keyBytes.length != 32 && keyBytes.length != 24
&& keyBytes.length != 16) {
throw new IllegalArgumentException(
"Key length must be   128/192/256 bits!");
}
decryptedBytes = decrypt(encryptedContent, keyBytes, INIT_VECTOR);
decrypted = new String(decryptedBytes);
return decrypted;
}


private static byte[] encrypt(byte[] plain, byte[] key, byte[] iv)
throws Exception {
PaddedBufferedBlockCipher aes = new PaddedBufferedBlockCipher(
new CBCBlockCipher(new AESFastEngine()));
CipherParameters ivAndKey = new ParametersWithIV(new KeyParameter(key),
iv);
aes.init(true, ivAndKey);
return cipherData(aes, plain);
}


private static byte[] decrypt(byte[] cipher, byte[] key, byte[] iv)
throws Exception {
PaddedBufferedBlockCipher aes = new PaddedBufferedBlockCipher(
new CBCBlockCipher(new AESFastEngine()));
CipherParameters ivAndKey = new ParametersWithIV(new KeyParameter(key),
iv);
aes.init(false, ivAndKey);
return cipherData(aes, cipher);
}


private static byte[] cipherData(PaddedBufferedBlockCipher cipher,
byte[] data) throws Exception {
int minSize = cipher.getOutputSize(data.length);
byte[] outBuf = new byte[minSize];
int length1 = cipher.processBytes(data, 0, data.length, outBuf, 0);
int length2 = cipher.doFinal(outBuf, length1);
int actualLength = length1 + length2;
byte[] result = new byte[actualLength];
System.arraycopy(outBuf, 0, result, 0, result.length);
return result;
}

使用：

public static void main(String[] args) {
try {
String apiKey = "222b8f353b79afb361e27b3523967928";
String content = "test12345";
long start = System.currentTimeMillis();
String encrypt = encrypt(content, apiKey);
System.out.println(System.currentTimeMillis() - start + "   ms");
System.out.println(encrypt);
String decrypt = decrypt(encrypt, apiKey);
System.out.println(decrypt);
} catch (Exception e) {
e.printStackTrace();
}
}