我正在尝试将this DES加密示例调整为AES,因此我进行了更改,并尝试运行此操作:
import java.io.File;
import java.io.FileInputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.security.spec.AlgorithmParameterSpec;
import javax.crypto.Cipher;
import javax.crypto.CipherInputStream;
import javax.crypto.CipherOutputStream;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.crypto.spec.IvParameterSpec;
// Adapted from http://www.exampledepot.com/egs/javax.crypto/DesFile.html
public class AesEncrypter {
private Cipher ecipher;
private Cipher dcipher;
// Buffer used to transport the bytes from one stream to another
private byte[] buf = new byte[1024];
public AesEncrypter(SecretKey key) throws Exception {
// Create an 8-byte initialization vector
byte[] iv = new byte[] { (byte) 0x8E, 0x12, 0x39, (byte) 0x9C, 0x07, 0x72, 0x6F, 0x5A };
AlgorithmParameterSpec paramSpec = new IvParameterSpec(iv);
ecipher = Cipher.getInstance("AES/CBC/NoPadding");
dcipher = Cipher.getInstance("AES/CBC/NoPadding");
// CBC requires an initialization vector
ecipher.init(Cipher.ENCRYPT_MODE, key, paramSpec);
dcipher.init(Cipher.DECRYPT_MODE, key, paramSpec);
}
public void encrypt(InputStream in, OutputStream out) throws Exception {
// Bytes written to out will be encrypted
out = new CipherOutputStream(out, ecipher);
// Read in the cleartext bytes and write to out to encrypt
int numRead = 0;
while ((numRead = in.read(buf)) >= 0) {
out.write(buf, 0, numRead);
}
out.close();
}
public void decrypt(InputStream in, OutputStream out) throws Exception {
// Bytes read from in will be decrypted
in = new CipherInputStream(in, dcipher);
// Read in the decrypted bytes and write the cleartext to out
int numRead = 0;
while ((numRead = in.read(buf)) >= 0) {
out.write(buf, 0, numRead);
}
out.close();
}
public static void main(String[] args) throws Exception {
System.out.println("Starting...");
SecretKey key = KeyGenerator.getInstance("AES").generateKey();
InputStream in = new FileInputStream(new File("/home/wellington/Livros/O Alienista/speechgen0001.mp3/"));
OutputStream out = System.out;
AesEncrypter encrypter = new AesEncrypter(key);
encrypter.encrypt(in, out);
System.out.println("Done!");
}
}
但我得到了例外:
InvalidAlgorithmParameterException: Wrong IV length: must be 16 bytes long
所以我试图通过改变
来解决AlgorithmParameterSpec paramSpec = new IvParameterSpec(iv);
的
AlgorithmParameterSpec paramSpec = new IvParameterSpec(iv, 0, 16);
但结果
IV buffer too short for given offset/length combination
我可以尝试直到它工作,但我想听听谁使用AES什么是常用的缓冲区大小?
答案 0 :(得分:4)
您的主要问题已得到解答,但我想补充一点,除非您知道自己在做什么,否则一般不应使用固定字符串IV。您可能还想使用PKCS5Padding而不是NoPadding。
答案 1 :(得分:3)
我认为它说它需要16个字节,但这只是8个字节:
byte[] iv = new byte[] {
(byte) 0x8E, 0x12, 0x39, (byte) 0x9C, 0x07, 0x72, 0x6F, 0x5A
};
也许试试这个?
byte[] iv = new byte[] {
(byte) 0x8E, 0x12, 0x39, (byte) 0x9C, 0x07, 0x72, 0x6F, 0x5A,
(byte) 0x8E, 0x12, 0x39, (byte) 0x9C, 0x07, 0x72, 0x6F, 0x5A
};