某些字符串

时间:2018-02-19 22:58:52

标签: java encryption cryptography base64 aes

我正在尝试通过网络发送受保护的文本,使用AES算法和Base64对其进行加密。对于我试过的几个文本,它工作正常,但有一些字符串没有正确解码。 我在字符串上发现了一个无法解码的模式。它们似乎是它们的突破线。 例: 加密步骤:

1)PlainText

2)AES加密文本:

即 l1?‰|6ÎÔ.jcæ÷Ï_ðNSO〜A'q @Ó[

3)BASE64 AES文本:

zWUNbDEgnz + JfDbO1C5qY + b3z1 / wTlNPmAdBknFA01s =

解密步骤:

1)BASE64 AES文本:

zWUNbDEgnz + JfDbO1C5qY + b3z1 / wTlNPmAdBknFA01s =

2)AES加密文本:

即 l1?‰|6ÎÔ.jcæ÷Ï_ðNSO〜A'q @Ó[

3)纯文本:

í¿Ð“tº“£¹ÍG‰\ IOE

我加密的任何其他文本都不包含加密版本的分隔线,这是正确解密的。

例如:

加密步骤:

1)纯文本:P @ $$ w0rd

2)AES加密文本:

÷÷Odã29ôÐÑÌe£ø™

3)Base64 AES文本:

9xH3T2TjMjn00NHMZaOZ + A ==

解密步骤:

3)Base64 AES文本:

9xH3T2TjMjn00NHMZaOZ + A ==

2)AES加密文本:

÷÷Odã29ôÐÑÌe£ø™

3)纯文本:

2P @ $$ w0rd

以下是我为此目的创建的对象。

Base64Codec对象:

package security;
import java.util.Base64;
import java.util.Base64.Decoder;
import java.util.Base64.Encoder;
public class Base64Codec
{
    private static Base64Codec objInstance;
    private Encoder objEncoder;
    private Decoder objDecoder;
    private Base64Codec()
    {
        this.setEncoder();
        this.setDecoder();
    }
    public static Base64Codec getInstance()
    {
        if (objInstance == null)
        {
            objInstance = new Base64Codec();
        }
        return objInstance;
    }
    private void setEncoder()
    {
        this.objEncoder = Base64.getEncoder();
    }
    private Encoder getEncoder()
    {
        return this.objEncoder;
    }
    private void setDecoder()
    {
        this.objDecoder = Base64.getDecoder();
    }
    private Decoder getDecoder()
    {
        return this.objDecoder;
    }
    protected String encode(String strValue)
    {
        return this.getEncoder().encodeToString(strValue.getBytes());
    }
    protected String decode(String strValue)
    {
        return new String(this.getDecoder().decode(strValue));
    }
}

AdvancedEncryptionStandard Object

package security;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.spec.SecretKeySpec;
public class AdvancedEncryptionStandard
{
    private static final String strKey = "02E68E02BE7400FE11E8A45B60017F98";
    private static final byte[] bytKey = strKey.getBytes();
    private static final String strAlgorithm = "AES";
    private static AdvancedEncryptionStandard objInstance;
    private Cipher objCipher;
    private SecretKeySpec objSecretKey;
    private AdvancedEncryptionStandard() throws NoSuchAlgorithmException, NoSuchPaddingException
    {
        this.setSecretKey();
        this.setCipher();
    }
    public static AdvancedEncryptionStandard getInstance() throws NoSuchAlgorithmException, NoSuchPaddingException
    {
        if (objInstance == null)
        {
            objInstance = new AdvancedEncryptionStandard();
        }
        return objInstance;
    }
    private byte[] getKey()
    {
        return bytKey;
    }
    private String getAlgorithm()
    {
        return strAlgorithm;
    }
    private void setSecretKey()
    {
        this.objSecretKey = new SecretKeySpec(this.getKey(), this.getAlgorithm());
    }
    private SecretKeySpec getSecretKey()
    {
        return this.objSecretKey;
    }
    private void setCipher() throws NoSuchAlgorithmException, NoSuchPaddingException
    {
        this.objCipher = Cipher.getInstance(this.getAlgorithm());
    }
    private Cipher getCipher()
    {
        return this.objCipher;
    }
    protected String encrypt(String strValue) throws InvalidKeyException, IllegalBlockSizeException, BadPaddingException
    {
        this.getCipher().init(Cipher.ENCRYPT_MODE, this.getSecretKey());
        return new String(this.getCipher().doFinal(strValue.getBytes()));
    }
    protected String decrypt(String strValue) throws InvalidKeyException, IllegalBlockSizeException, BadPaddingException
    {
        this.getCipher().init(Cipher.DECRYPT_MODE, this.getSecretKey());
        return new String(this.getCipher().doFinal(strValue.getBytes()));
    }
}

SecureText对象

package security;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import javax.crypto.BadPaddingException;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.NoSuchPaddingException;
public class SecureText
{
    private static SecureText objInstance;
    private SecureText()
    {

    }
    public static SecureText getInstance()
    {
        if (objInstance == null)
        {
            objInstance = new SecureText();
        }
        return objInstance;
    }
    public String encode(String strValue) throws InvalidKeyException, IllegalBlockSizeException, BadPaddingException, NoSuchAlgorithmException, NoSuchPaddingException
    {
        return Base64Codec.getInstance().encode(AdvancedEncryptionStandard.getInstance().encrypt(strValue));
    }
    public String decode(String strValue) throws InvalidKeyException, IllegalBlockSizeException, BadPaddingException, NoSuchAlgorithmException, NoSuchPaddingException
    {
        return AdvancedEncryptionStandard.getInstance().decrypt(Base64Codec.getInstance().decode(strValue));
    }
}

测试:

public static void main(String[] args)
    {
//Test SecureText Object. AES and Base64
        String strSecureText = <plain text>
        System.out.println(strSecureText);
        System.out.println(SecureText.getInstance().decode(strSecureText));
//Test AES and Base64 separated
        String strCoded;
        String strEncrypted;
        String strDecrypted;
        String strDecoded;
        strEncrypted = AdvancedEncryptionStandard.getInstance().encrypt(<plain text>);
        System.out.println(strEncrypted);
        strCoded = Base64Codec.getInstance().encode(strEncrypted);
        System.out.println(strCoded);
        strDecoded = Base64Codec.getInstance().decode(strCoded);
        System.out.println(strDecoded);
        strDecrypted = AdvancedEncryptionStandard.getInstance().decrypt(strDecoded);
        System.out.println(strDecrypted);
        String strSecureText = SecureText.getInstance().encode(<plain text>);
    }

1 个答案:

答案 0 :(得分:1)

我看到你的代码有两个问题(关于加密,对于你已经有足够评论的结构)

  

对于我尝试过的几个文本,它工作正常,但有一些字符串未正确解码。我在字符串上发现了一个无法解码的模式。

永远不要尝试将Java中的随机字节数组表示为String。 JVM将尝试暗示字符集转换,您可能会丢失/更改数据。将String转换为字节时同样适用,最好明确说明编码。

加密数据只是一个字节数组,一旦计划打印它们,就将字节数组编码为可读的内容,例如hex或base64。请勿使用new String(encryptedArray)

下一个问题是我没有看到你使用IV(而且似乎要求进行身份验证加密),请阅读我的blog about how to do encryption at least almost properly