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我是密码学的新手。我正在开发一个 poc 来加密和解密一个字符串。当我解密加密的字符串时，它有时会起作用，但有时会引发标签不匹配错误。我错过了什么吗？

这是我的代码：

EncryptionServiceImpl.java

public class EncryptionServiceImpl {
    private static final Logger log = LoggerFactory.getLogger("EncryptionServiceImpl");

    private final KeysetHandle keysetHandle;
    private final Aead aead;

    public EncryptionServiceImpl() throws GeneralSecurityException {
        AeadConfig.register();
        this.keysetHandle = KeysetHandle.generateNew(AeadKeyTemplates.AES128_GCM);
        aead = AeadFactory.getPrimitive(keysetHandle);
    }

    public String encrypt(String text) throws GeneralSecurityException {

        log.info(String.format("Encrypting %s", text));
        byte[] plainText = text.getBytes();
        byte[] additionalData = "masterkey".getBytes();
        byte[] cipherText = aead.encrypt(plainText,additionalData);

        String output = new String(cipherText);

        log.info(String.format("The encrypted text: %s", output));
        return output;
    }

    public String decrypt(String text) throws GeneralSecurityException {

        log.info(String.format("Decrypting %s", text));

        byte[] cipherText = text.getBytes();
        byte[] additionalData = "masterkey".getBytes();
        byte[] decipheredData = aead.decrypt(cipherText,additionalData);

        String output = new String(decipheredData);

        log.info(String.format("The decrypted text: %s", output));
        return output;
    }

}

EncryptionServiceImplTest.java

public class EncryptionServiceImplTest {

    @Test
    public void encrypt() throws IOException, GeneralSecurityException {
        EncryptionServiceImpl encryptionService = new EncryptionServiceImpl();
        String encryptedText = encryptionService.encrypt("Hello World");
        assertThat(encryptedText, Matchers.notNullValue());
    }

    @Test
    public void decrypt() throws IOException, GeneralSecurityException {
        EncryptionServiceImpl encryptionService = new EncryptionServiceImpl();

        String encryptedText = encryptionService.encrypt("Hello World");
        String decrypedText = encryptionService.decrypt(encryptedText);

        assertThat(decrypedText, Matchers.is("Hello World"));
    }
}

异常：INFO：密文前缀匹配密钥，但无法解密：javax.crypto.AEADBadTagException：标签不匹配！com.encryption.api.service.EncryptionServiceImplTest > 解密失败

java.security.GeneralSecurityException at EncryptionServiceImplTest.java:25

java.security.GeneralSecurityException 解密失败：com.encryption.api.service.EncryptionServiceImpl.decrypt(EncryptionServiceImpl.java:53 处的 com.google.crypto.tink.aead.AeadFactory$1.decrypt(AeadFactory.java:109) 解密失败) 在 com.encryption.api.service.EncryptionServiceImplTest.decrypt(EncryptionServiceImplTest.java:25) 在 sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) 在 sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) 在 sun。 reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498) at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50) at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12) 在 org.junit。runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47) at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17) at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java: 325) 在 org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78) 在 org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57) 在 org.junit.runners.ParentRunner$3.run(ParentRunner. java:290) at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71) at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288) at org.junit.runners.ParentRunner.access$000 (ParentRunner.java:58) at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268) at org.junit.runners.ParentRunner.run(ParentRunner.java:363) at org.gradle.api.internal .tasks.testing.junit.JUnitTestClassExecuter.runTestClass(JUnitTestClassExecuter.java:114) 在 org.gradle.api.internal.tasks.testing.junit.JUnitTestClassExecuter.execute(JUnitTestClassExecuter.java:57) 在 org.gradle.api.internal。 tasks.testing.junit.JUnitTestClassProcessor.processTestClass(JUnitTestClassProcessor.java:66) 在 org.gradle.api.internal.tasks.testing.SuiteTestClassProcessor.processTestClass(SuiteTestClassProcessor.java:51) 在 sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method ) 在 sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) 在 sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) 在 java.lang.reflect.Method.invoke(Method.java:498) 在 org .gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:35) 在 org.gradle。internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:24) at org.gradle.internal.dispatch.ContextClassLoaderDispatch.dispatch(ContextClassLoaderDispatch.java:32) at org.gradle.internal.dispatch.ProxyDispatchAdapter$DispatchingInvocationHandler.invoke(ProxyDispatchAdapter. java:93) 在 com.sun.proxy.$Proxy1.processTestClass(Unknown Source) 在 org.gradle.api.internal.tasks.testing.worker.TestWorker.processTestClass(TestWorker.java:108) 在 sun.reflect.NativeMethodAccessorImpl .invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java :498) 在 org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:35) 在 org.gradle.internal.remote.internal.hub.MessageHubBackedObjectConnection$DispatchWrapper.dispatch(MessageHubBackedObjectConnection.java:146) 在 org.gradle 的 org.gradle.internal.dispatch.ReflectionDispatch.dispatch(ReflectionDispatch.java:24) .internal.remote.internal.hub.MessageHubBackedObjectConnection$DispatchWrapper.dispatch(MessageHubBackedObjectConnection.java:128) 在 org.gradle.internal.remote.internal.hub.MessageHub$Handler.run(MessageHub.java:404) 在 org.gradle .internal.concurrent.ExecutorPolicy$CatchAndRecordFailures.onExecute(ExecutorPolicy.java:63) at org.gradle.internal.concurrent.ManagedExecutorImpl$1.run(ManagedExecutorImpl.java:46) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor. java:1149) 在 java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) 在 org.gradle.internal.concurrent.ThreadFactoryImpl$ManagedThreadRunnable.run(ThreadFactoryImpl.java:55) 在 java.lang.Thread.run(Thread.java:748)

1 次测试完成，1 次失败

4

3 回答 3

2

如果加密消息的字节序列存储在字符串中，则必须使用适当的编码。适当意味着编码必须允许序列中的所有字节或字节组合。如果不是这种情况，则字节序列中的值会在存储期间自动更改并且不会被注意到。如果在解密期间从字符串中重建字节数组，则原始字节数组和重建的字节数组不同并且解密失败。这在这里得到了很好的解释。

由于AES-GCM为每次加密生成一个新的初始化向量，因此每次加密的加密消息都是不同的，即使明文相同。

两者都导致在您的示例中，加密有时有效，有时无效：只要字节序列与您使用的编码兼容，解密就有效，否则无效。

如果您想独立于编码，只需使用字节数组本身，即encrypt- 方法返回字节数组而不是字符串，类似地，字节数组而不是字符串传递给decrypt- 方法。

于 2019-04-09T11:25:17.183 回答
0

I revised the code but still I see that the decryption fails for the same request sometimes. 

public class Utils {
private static final Logger log = LoggerFactory.getLogger(Utils.class);
private Aead aead;
private static Utils utils;

private Utils() {
    try {
        AeadConfig.register();
        KeysetHandle keysetHandle = KeysetHandle.generateNew(AeadKeyTemplates.AES128_GCM);
        aead = AeadFactory.getPrimitive(keysetHandle);
    } catch (GeneralSecurityException e) {
        log.error(String.format("Error occured: %s",e.getMessage())).log();
    }
}

public static Utils getInstance() {
    if(null == utils) {
        utils = new Utils();
    }

    return utils;
}

public String encrypt(String text) throws GeneralSecurityException, UnsupportedEncodingException {
    byte[] plainText = text.getBytes("ISO-8859-1");
    byte[] additionalData = null;
    byte[] cipherText = aead.encrypt(plainText,additionalData);

    String output = Base64.getEncoder().encodeToString(cipherText);
    return output;
}

public String decrypt(String text) throws GeneralSecurityException, UnsupportedEncodingException {
    byte[] cipherText = Base64.getDecoder().decode(text);
    byte[] additionalData = null;
    byte[] decipheredData = aead.decrypt(cipherText,additionalData);

    String output = new String(decipheredData,"ISO-8859-1");
    return output;
}

}

于 2019-04-12T16:31:21.187 回答
0

当我在本地机器上运行时，我也没有收到代码错误。但是当我部署在云（谷歌云）中时，我开始看到错误。

这是我的Junit代码：

public class UtilsTest {

private static final Utils cryptographicUtils = Utils.getInstance();

@Test
public void encrypt() throws IOException, GeneralSecurityException {
    String encryptedText = cryptographicUtils.encrypt("Hello World");
    assertThat(encryptedText, Matchers.notNullValue());
}

@Test
public void decrypt() throws IOException, GeneralSecurityException {
    String encryptedText = cryptographicUtils.encrypt("Hello 123456");
    String decrypedText = cryptographicUtils.decrypt(encryptedText);

    assertThat(decrypedText, Matchers.is("Hello 123456"));
}

}

于 2019-04-12T20:41:56.980 回答