我已经想了好几天了。加密方法工作正常，但在解密测试期间，我得到了下面的异常。尤其是我在使用： AES/GCM/NoPadding . 据我所知 T_LEN 应该是 IV_LENGTH*8 作为字节数组表示。错误在examplecryptografer.java解密方法中显示： byte[] decryptedText = cipher.doFinal(decoded); ```
javax.crypto.AEADBadTagException: Tag mismatch!

at java.base/com.sun.crypto.provider.GaloisCounterMode.decryptFinal(GaloisCounterMode.java:623)
at java.base/com.sun.crypto.provider.CipherCore.finalNoPadding(CipherCore.java:1116)
at java.base/com.sun.crypto.provider.CipherCore.fillOutputBuffer(CipherCore.java:1053)
at java.base/com.sun.crypto.provider.CipherCore.doFinal(CipherCore.java:853)
at java.base/com.sun.crypto.provider.AESCipher.engineDoFinal(AESCipher.java:446)
at java.base/javax.crypto.Cipher.doFinal(Cipher.java:2202)
at com.example.ExampleCryptografer.decrypt(ExampleCryptografer.java:61)
at com.example.ExampleCryptograferTest.decrypt_givenEncryptedExample_ShouldSucceed(ExampleCryptograferTest.java:21)

我的测试是这样的：

public class ExampleCryptographerTest {

private ExampleCryptographer objectUnderTest = new ExampleCryptographer("knownKeyForTest=");

@Test
public void decrypt_givenEncryptedExample_ShouldSucceed() {
String example = "afasfdafafa=";
String encodedExample = objectUnderTest.encrypt(example);

String result = objectUnderTest.decrypt(encodedExample);

assertThat(result).isNotNull();
assertThat(result.length()).isEqualTo(48);

}

@Test
public void encrypt_givenExample_ShouldSucceed() {
String example = "afasfdafafa=";

String result = objectUnderTest.encrypt(example);

assertThat(result).isNotNull();
assertThat(result.length()).isEqualTo(48);

}

@Test
public void decrypt_givenEncryptedExampleWithOtherKey_ShouldFail() {
String example = "afasfdafafa=";
String encodedExample = new ExampleCryptographer("otherKeyForTest=").encrypt(example);

Throwable throwable = catchThrowable(() -> objectUnderTest.decrypt(encodedExample));

assertThat(throwable)
    .isInstanceOf(IllegalArgumentException.class);

}

@Test(expected = InvalidKeyException.class)
public void encrypt_givenInvalidKey_ShouldFail() {
new ExampleCryptographer("invalid").encrypt("test");
}

}
最后是实际代码：

public class ExampleCryptographer {

private static final String ALGORITHM = "AES";

private final Key key;
private static final int T_LEN = 96;
private static final int IV_LENGTH = 12;
private final Base64 base64 = new Base64(76, null, true);

@SneakyThrows
public ExampleCryptographer(@Value("${myKey}") String secretKey) {
this.key = new SecretKeySpec(secretKey.getBytes(), ALGORITHM);
}

@SneakyThrows
public String encrypt(@NonNull String text) {
byte[] iv = new byte[IV_LENGTH];
(new SecureRandom()).nextBytes(iv);

Cipher cipher = Cipher.getInstance("AES/GCM/NoPadding");
GCMParameterSpec ivSpec = new GCMParameterSpec(T_LEN, iv);
cipher.init(Cipher.ENCRYPT_MODE, key, ivSpec);

byte[] ciphertext = cipher.doFinal(text.getBytes(UTF_8));
byte[] encrypted = new byte[iv.length + ciphertext.length];
System.arraycopy(iv, 0, encrypted, 0, iv.length);
System.arraycopy(ciphertext, 0, encrypted, iv.length, ciphertext.length);

return base64.encodeAsString(encrypted);

}

@SneakyThrows
public String decrypt(@NonNull String encryptedText) {
byte[] decoded = base64.decode(encryptedText);

byte[] iv = Arrays.copyOfRange(decoded, 0, IV_LENGTH);

Cipher cipher = Cipher.getInstance("AES/GCM/NoPadding");
GCMParameterSpec ivSpec = new GCMParameterSpec(T_LEN, iv);
cipher.init(Cipher.DECRYPT_MODE, key, ivSpec);

byte[] decryptedText = cipher.doFinal(decoded);

return new String(decryptedText);

}

}
有人能帮忙吗？我已经读了很多关于这个的书，但仍然没有发现任何错误。