带有Bouncy Castle的256位AES / CBC / PKCS5Padding

我无法将以下JDK JCE加密代码映射到Bouncy Castles Light-weight API：

public String dec(String password, String salt, String encString) throws Throwable { // AES algorithm with CBC cipher and PKCS5 padding Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding", "BC"); // Construct AES key from salt and 50 iterations PBEKeySpec pbeEKeySpec = new PBEKeySpec(password.toCharArray(), toByte(salt), 50, 256); SecretKeyFactory keyFactory = SecretKeyFactory.getInstance("PBEWithSHA256And256BitAES-CBC-BC"); SecretKeySpec secretKey = new SecretKeySpec(keyFactory.generateSecret(pbeEKeySpec).getEncoded(), "AES"); // IV seed for first block taken from first 32 bytes byte[] ivData = toByte(encString.substring(0, 32)); // AES encrypted data byte[] encData = toByte(encString.substring(32)); cipher.init( Cipher.DECRYPT_MODE, secretKey, new IvParameterSpec( ivData ) ); return new String( cipher.doFinal( encData ) ); } 

由于Oracle对加密强度的限制，上述工作很好，但不是很便携。 我已经多次尝试移植到Bouncy Castles Light-weight API但没有成功。

 public String decrypt1(String password, String salt, String encString) throws Exception { byte[] ivData = toByte(encString.substring(0, 32)); byte[] encData = toByte(encString.substring(32)); PKCS12ParametersGenerator gen = new PKCS12ParametersGenerator(new SHA256Digest()); gen.init(password.getBytes(), toByte(salt), 50); CBCBlockCipher cbcBlockcipher = new CBCBlockCipher(new RijndaelEngine(256)); CipherParameters params = gen.generateDerivedParameters(256, 256); cbcBlockcipher.init(false, params); PaddedBufferedBlockCipher aesCipher = new PaddedBufferedBlockCipher(cbcBlockcipher, new PKCS7Padding()); byte[] plainTemp = new byte[aesCipher.getOutputSize(encData.length)]; int offset = aesCipher.processBytes(encData, 0, encData.length, plainTemp, 0); int last = aesCipher.doFinal(plainTemp, offset); byte[] plain = new byte[offset + last]; System.arraycopy(plainTemp, 0, plain, 0, plain.length); return new String(plain); } 

上述尝试导致org.bouncycastle.crypto.DataLengthException：最后一个块在解密时不完整。

我在网上搜索了一些例子，但是没有很多例子可以使用PKCS5 / PKCS7作为填充为CBC提供256位AES的IV数据。

注意：toByte函数使用base64或类似函数将String转换为字节数组。

Answer 1

这应该适合你：

 public String dec(String password, String salt, String encString) throws Exception { byte[] ivData = toByte(encString.substring(0, 32)); byte[] encData = toByte(encString.substring(32)); // get raw key from password and salt PBEKeySpec pbeKeySpec = new PBEKeySpec(password.toCharArray(), toByte(salt), 50, 256); SecretKeyFactory keyFactory = SecretKeyFactory .getInstance("PBEWithSHA256And256BitAES-CBC-BC"); SecretKeySpec secretKey = new SecretKeySpec(keyFactory.generateSecret( pbeKeySpec).getEncoded(), "AES"); byte[] key = secretKey.getEncoded(); // setup cipher parameters with key and IV KeyParameter keyParam = new KeyParameter(key); CipherParameters params = new ParametersWithIV(keyParam, ivData); // setup AES cipher in CBC mode with PKCS7 padding BlockCipherPadding padding = new PKCS7Padding(); BufferedBlockCipher cipher = new PaddedBufferedBlockCipher( new CBCBlockCipher(new AESEngine()), padding); cipher.reset(); cipher.init(false, params); // create a temporary buffer to decode into (it'll include padding) byte[] buf = new byte[cipher.getOutputSize(encData.length)]; int len = cipher.processBytes(encData, 0, encData.length, buf, 0); len += cipher.doFinal(buf, len); // remove padding byte[] out = new byte[len]; System.arraycopy(buf, 0, out, 0, len); // return string representation of decoded bytes return new String(out, "UTF-8"); } 

我假设您实际上正在为toByte()执行hex编码，因为您的代码使用32个字符作为IV（提供必要的16个字节）。 虽然我没有用于加密的代码，但我确实validation了此代码将提供与代码相同的解密输出。