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Android中的RSA加密解密

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Android中的RSA加密解密,android,rsa,public-key-encryption,encryption,Android,Rsa,Public Key Encryption,Encryption,我正在Android中实现RSA加密和解密的演示。我可以很好地执行加密，但在解密过程中我遇到了一个异常：>java.security.InvalidKeyException:传递给RSA的未知密钥类型 KeyPairGenerator kpg; KeyPair kp; PublicKey publicKey; PrivateKey privateKey; byte [] encryptedBytes,decryptedBytes; Cipher c

我正在Android中实现RSA加密和解密的演示。我可以很好地执行加密，但在解密过程中我遇到了一个异常：
>java.security.InvalidKeyException:传递给RSA的未知密钥类型

    KeyPairGenerator kpg;
    KeyPair kp;
    PublicKey publicKey;
    PrivateKey privateKey;
    byte [] encryptedBytes,decryptedBytes;
    Cipher cipher,cipher1;
    String encrypted,decrypted;

    public String RSAEncrypt (final String plain) throws NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException, IllegalBlockSizeException, BadPaddingException 
    {
        kpg = KeyPairGenerator.getInstance("RSA");
        kpg.initialize(1024);
        kp = kpg.genKeyPair();
        publicKey = kp.getPublic();
        privateKey = kp.getPrivate();

        cipher = Cipher.getInstance("RSA");
        cipher.init(Cipher.ENCRYPT_MODE, publicKey);
        encryptedBytes = cipher.doFinal(plain.getBytes());
        encrypted = new String(encryptedBytes);
        System.out.println("EEncrypted?????"+encrypted);
        return encrypted;

    }

    public String RSADecrypt (final String result) throws NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException, IllegalBlockSizeException, BadPaddingException 
    {

        cipher1=Cipher.getInstance("RSA");
        cipher1.init(Cipher.DECRYPT_MODE, privateKey);
        decryptedBytes = cipher1.doFinal(result.getBytes());
        decrypted = new String(decryptedBytes);
        System.out.println("DDecrypted?????"+decrypted);
        return decrypted;

    }
我从这里调用函数：

encrypt.setOnClickListener(new OnClickListener()
        { 
            public void onClick(View arg0) 
            {
                    try
                    {
                        RSAEncrypt rsaencrypt=new RSAEncrypt();
                        rsaencrypt.RSAEncrypt(name);

                        result=rsaencrypt.RSAEncrypt(name);
                        Toast.makeText(getBaseContext(), result.toString(),Toast.LENGTH_SHORT).show();

                        System.out.println("Result:"+result);
                    }
                    catch(Exception e)
                    {
                        e.printStackTrace();
                        Toast.makeText(getBaseContext(), e.toString(),Toast.LENGTH_LONG).show();
                    }
            }
        });

        decrypt.setOnClickListener(new OnClickListener()
        { 
            public void onClick(View arg0) 
            {
                {
                    try
                    {
                        RSAEncrypt rsadecrypt=new RSAEncrypt();

                        rsadecrypt.RSADecrypt(result);

                        ans=rsadecrypt.RSADecrypt(result);
                        System.out.println("Result is"+ans);
                        Toast.makeText(getBaseContext(), ans.toString(),Toast.LENGTH_LONG).show();
                    }
                    catch(Exception e)
                    {
                        e.printStackTrace();
                        Toast.makeText(getBaseContext(), e.toString(),Toast.LENGTH_LONG).show();
                        System.out.println("Exception is>>"+e);
                    }
            }
        });
我认为问题在于，您应该使用相同的密钥对加密和解密密码。参考JavaDoc：

 genKeyPair() This will generate a new key pair every time it is called.
在RSA中，您应该使用公钥进行加密，使用私钥进行解密

您的示例代码使用公钥进行加密和解密-这无法工作

因此，在解密部分，您应该以以下方式初始化密码：

cipher1.init(Cipher.DECRYPT_MODE, privateKey);
此外，如果您的代码还有第二个重要错误：

您正在将包含二进制内容的字节数组转换为字符串

永远不要将二进制数据转换为字符串

字符串用于字符串字符，而不是二进制数据。如果要将二进制数据打包成字符串，请将其编码为可打印字符，例如使用十六进制或Base64

以下示例使用十六进制编码器fro软件包-必须安装第三方库

public byte[] RSAEncrypt(final String plain) throws NoSuchAlgorithmException, NoSuchPaddingException,
        InvalidKeyException, IllegalBlockSizeException, BadPaddingException {
    kpg = KeyPairGenerator.getInstance("RSA");
    kpg.initialize(2048);
    kp = kpg.genKeyPair();
    publicKey = kp.getPublic();
    privateKey = kp.getPrivate();

    cipher = Cipher.getInstance("RSA");
    cipher.init(Cipher.ENCRYPT_MODE, publicKey);
    encryptedBytes = cipher.doFinal(plain.getBytes());
    System.out.println("EEncrypted?????" + new String(org.apache.commons.codec.binary.Hex.encodeHex(encryptedBytes)));
    return encryptedBytes;
}

public String RSADecrypt(final byte[] encryptedBytes) throws NoSuchAlgorithmException, NoSuchPaddingException,
        InvalidKeyException, IllegalBlockSizeException, BadPaddingException {

    cipher1 = Cipher.getInstance("RSA");
    cipher1.init(Cipher.DECRYPT_MODE, privateKey);
    decryptedBytes = cipher1.doFinal(encryptedBytes);
    decrypted = new String(decryptedBytes);
    System.out.println("DDecrypted?????" + decrypted);
    return decrypted;
}
使用RSAEcvypt方法时，其填充公钥和私钥。 当您解密生成的字节[]时，您的公钥和私钥为空。 正因为如此，您得到了这个错误

你应该使用你的钥匙

enter code here

KeyPairGenerator kpg;
KeyPair kp;
static PublicKey publicKey;
static PrivateKey privateKey;
byte [] encryptedBytes,decryptedBytes;
Cipher cipher,cipher1;
String encrypted,decrypted;
我的班级：

package com.infovale.cripto;

import java.io.UnsupportedEncodingException;
import java.math.BigInteger;
import java.security.InvalidKeyException;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.NoSuchAlgorithmException;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.util.Arrays;

import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.NoSuchPaddingException;

public class RSA {

KeyPairGenerator kpg;
KeyPair kp;
PublicKey publicKey;
PrivateKey privateKey;
byte[] encryptedBytes, decryptedBytes;
Cipher cipher, cipher1;
String encrypted, decrypted;

public String Encrypt (String plain) throws NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException, IllegalBlockSizeException, BadPaddingException 
{
    kpg = KeyPairGenerator.getInstance("RSA");
    kpg.initialize(1024);
    kp = kpg.genKeyPair();
    publicKey = kp.getPublic();
    privateKey = kp.getPrivate();

    cipher = Cipher.getInstance("RSA");
    cipher.init(Cipher.ENCRYPT_MODE, publicKey);
    encryptedBytes = cipher.doFinal(plain.getBytes());

    encrypted = bytesToString(encryptedBytes);
    return encrypted;

}

public String Decrypt (String result) throws NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException, IllegalBlockSizeException, BadPaddingException 
{           

    cipher1=Cipher.getInstance("RSA");
    cipher1.init(Cipher.DECRYPT_MODE, privateKey);
    decryptedBytes = cipher1.doFinal(stringToBytes(result));
    decrypted = new String(decryptedBytes);
    return decrypted;

}

public  String bytesToString(byte[] b) {
    byte[] b2 = new byte[b.length + 1];
    b2[0] = 1;
    System.arraycopy(b, 0, b2, 1, b.length);
    return new BigInteger(b2).toString(36);
}

public  byte[] stringToBytes(String s) {
    byte[] b2 = new BigInteger(s, 36).toByteArray();
    return Arrays.copyOfRange(b2, 1, b2.length);
}
}
以下是Android的一个示例：

  • 生成私有/公共RSA密钥对
  • 加密字符串
  • 解密加密字符串
这些方法处理所有的base64编码/解码

    public void TestEncryptData(String dataToEncrypt) {
        // generate a new public/private key pair to test with (note. you should only do this once and keep them!)
        KeyPair kp = getKeyPair();

        PublicKey publicKey = kp.getPublic();
        byte[] publicKeyBytes = publicKey.getEncoded();
        String publicKeyBytesBase64 = new String(Base64.encode(publicKeyBytes, Base64.DEFAULT));

        PrivateKey privateKey = kp.getPrivate();
        byte[] privateKeyBytes = privateKey.getEncoded();
        String privateKeyBytesBase64 = new String(Base64.encode(privateKeyBytes, Base64.DEFAULT));

        // test encryption
        String encrypted = encryptRSAToString(dataToEncrypt, publicKeyBytesBase64);

        // test decryption
        String decrypted = decryptRSAToString(encrypted, privateKeyBytesBase64);
    }

    public static KeyPair getKeyPair() {
        KeyPair kp = null;
        try {
            KeyPairGenerator kpg = KeyPairGenerator.getInstance("RSA");
            kpg.initialize(2048);
            kp = kpg.generateKeyPair();
        } catch (Exception e) {
            e.printStackTrace();
        }

        return kp;
    }

    public static String encryptRSAToString(String clearText, String publicKey) {
        String encryptedBase64 = "";
        try {
            KeyFactory keyFac = KeyFactory.getInstance("RSA");
            KeySpec keySpec = new X509EncodedKeySpec(Base64.decode(publicKey.trim().getBytes(), Base64.DEFAULT));
            Key key = keyFac.generatePublic(keySpec);

            // get an RSA cipher object and print the provider
            final Cipher cipher = Cipher.getInstance("RSA/ECB/OAEPWITHSHA-256ANDMGF1PADDING");
            // encrypt the plain text using the public key
            cipher.init(Cipher.ENCRYPT_MODE, key);

            byte[] encryptedBytes = cipher.doFinal(clearText.getBytes("UTF-8"));
            encryptedBase64 = new String(Base64.encode(encryptedBytes, Base64.DEFAULT));
        } catch (Exception e) {
            e.printStackTrace();
        }

        return encryptedBase64.replaceAll("(\\r|\\n)", "");
    }

    public static String decryptRSAToString(String encryptedBase64, String privateKey) {

        String decryptedString = "";
        try {
            KeyFactory keyFac = KeyFactory.getInstance("RSA");
            KeySpec keySpec = new PKCS8EncodedKeySpec(Base64.decode(privateKey.trim().getBytes(), Base64.DEFAULT));
            Key key = keyFac.generatePrivate(keySpec);

            // get an RSA cipher object and print the provider
            final Cipher cipher = Cipher.getInstance("RSA/ECB/OAEPWITHSHA-256ANDMGF1PADDING");
            // encrypt the plain text using the public key
            cipher.init(Cipher.DECRYPT_MODE, key);

            byte[] encryptedBytes = Base64.decode(encryptedBase64, Base64.DEFAULT);
            byte[] decryptedBytes = cipher.doFinal(encryptedBytes);
            decryptedString = new String(decryptedBytes);
        } catch (Exception e) {
            e.printStackTrace();
        }

        return decryptedString;
    }
@jaredzhang..我编辑了我的代码..但我得到了相同的异常..请检查我编辑的代码..@jaredzhang..我认为你是对的..但问题是现在我得到了java.lang.NullPointerException..你的新代码似乎不清楚，请确保您用于解密的私钥与之前生成的相同。@jaredzhang..嗨..我再次编辑了我的代码..因此..您似乎很清楚..请帮助我..非常感谢..并查看我的问题..到目前为止，我得到的例外情况也不同..@jaredzhang，因此这不能用于将数据从一个应用发送到另一个应用另一个as接收器应用程序将调用genKeyPair（）并创建不同的密钥。任何解决方案？非常感谢..你是对的..我在这方面犯了错误..但现在我得到了异常>>System.err（416）：java.security.InvalidKeyException:传递给RSA的未知密钥类型请帮助我..提前谢谢..谢谢。只需一句话：按键是对称的。因此，您可以使用public编码，然后使用private解码（确保向谁发送加密数据），或者使用private编码，然后使用public解码（确保谁向您发送加密数据）。执行2（使用2个不同的密钥集），允许您同时执行“从谁”和“到谁”安全方面的操作。“使用私有编码”案例称为签名。但是您不应该直接对数据进行签名-始终只对has进行签名，否则您可能会遇到一些攻击（请参阅IT安全文献）。始终只对什么进行签名？“始终只对哈希进行签名”（SHA-256或SHA-1或…）这些都是类属性，因为访问这些键的方法不是静态的，因此属性不必是静态的。事实上，使用静态属性是一个非常糟糕的选择，特别是当您可能需要创建具有不同数据值的类的多个实例时