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,但是在解密中我得到一个异常:
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;
}
我从这里调用该函数:
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);
}
}
});
RSA您应该使用公钥进行加密,使用私钥进行解密。
您的示例代码用于加密和解密公钥-这无法工作。
因此,在解密部分,您应该以这种方式初始化密码:
cipher1.init(Cipher.DECRYPT_MODE, privateKey);
此外,您的代码还有第二个重要bug:
您正在将具有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到String中,请将其编码为可打印字符,例如使用Hex或Base64。
以下示例使用来自org. apache.公共.编解码器包的十六进制编码器-必须安装的第三方库。
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;
}
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的示例:
这些方法处理所有base 64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;
}