我正在开发一些 Java 软件，它需要使用两个单独的软件在网络连接的两端加密和解密信息。为了缓解这个问题，我有一个类 Cryptographer 来处理数据的加密。截至目前，Controller（连接的一侧）和 Agent（另一侧）都使用此类根据两个程序之间共享的密码生成 SecretKey。
密钥是在 Cryptographer 类的这个函数中生成的：
public SecretKey generateKey(String key) {
this._paramSpec = new PBEParameterSpec(this.SALT, this.ITERATION_COUNT);
PBEKeySpec spec = new PBEKeySpec(key.toCharArray());
SecretKeyFactory fac = null;
try {
fac = SecretKeyFactory.getInstance("PBEWithMD5AndDES");
} catch (NoSuchAlgorithmException ex) {
ex.printStackTrace();
System.err.println("[ERR] Cryptographer could not create a SecretKeyFactory due to an unsupported algorithm.");
}
try {
if (fac == null)
return null;
return fac.generateSecret(spec);
} catch (InvalidKeySpecException ex) {
System.err.println("[ERR] Cryptographer could not generate a SecretKey due to an invalid Key Specification.");
ex.printStackTrace();
return null;
}
}
加密本身发生在 encrypt 函数中：
public byte[] encrypt(byte[] message) {
try {
this._cipher.init(Cipher.ENCRYPT_MODE, this._key, this._paramSpec);
} catch (InvalidKeyException ex) {
System.err.println("[ERR] Cryptographer could not encrypt a message because the provided key is invalid.");
ex.printStackTrace();
return new byte[0];
} catch (InvalidAlgorithmParameterException ex) {
System.err.println("[ERR] Cryptographer could not encrypt a message because the parameters are invalid.");
ex.printStackTrace();
return new byte[0];
}
try {
return this._cipher.doFinal(message);
} catch (IllegalBlockSizeException ex) {
System.err.println("[ERR] Cryptographer could not encrypt a message due to an illegal block size.");
ex.printStackTrace();
return new byte[0];
} catch (BadPaddingException ex) {
System.err.println("[ERR] Cryptographer could not encrypt a message due to bad padding.");
ex.printStackTrace();
return new byte[0];
}
}
它被解密函数解密：
public byte[] decrypt(byte[] message) {
try {
this._cipher.init(Cipher.DECRYPT_MODE, this._key, this._paramSpec);
} catch (InvalidKeyException ex) {
System.err.println("[ERR] Cryptographer could not decrypt a message because the provided key is invalid.");
return new byte[0];
} catch (InvalidAlgorithmParameterException ex) {
System.err.println("[ERR] Cryptographer could not decrypt a message because the parameters are invalid.");
}
try {
return this._cipher.doFinal(message);
} catch (IllegalBlockSizeException ex) {
System.err.println("[ERR] Cryptographer could not decrypt a message due to an illegal block size.");
return new byte[0];
} catch (BadPaddingException ex) {
System.err.println("[ERR] Cryptographer could not decrypt a message due to bad padding.");
return new byte[0];
}
}
加密似乎工作正常，但是当我尝试在接收端解密序列化对象时，会抛出 InvalidKeyException。比较在控制器和代理上独立生成的密钥表明，尽管它们来自相同的密码，但它们不会生成相同的密钥。
现在，我是 Java 加密的新手，所以我完全有可能在这里做错了什么。似乎我缺少一个随机元素。目标是让连接的每一端从相同的密码生成相同的密钥。那么我在做什么显然是错误的？如果您需要查看更多代码，请告诉我。我很乐意发布它。