java rsa 解密报:javax.crypto.IllegalBlockSizeException: Data must not be longer than 117 bytes

水深无声 2022-05-26 07:08 362阅读 0赞

Exception in thread "main" javax.crypto.IllegalBlockSizeException: Data must not be longer than 117 bytes  
    at com.sun.crypto.provider.RSACipher.doFinal(RSACipher.java:344)  
    at com.sun.crypto.provider.RSACipher.engineDoFinal(RSACipher.java:389)  
    at javax.crypto.Cipher.doFinal(Cipher.java:2165)  
    at com.asymmetric.rsa.TestRSA.testDecrypt(TestRSA.java:82)

at com.asymmetric.rsa.TestRSA.main(TestRSA.java:33)

**异常解释**

加密块大小错误,rsa 加密 块大小为117 ,解密块大小为128 ,和公钥加密或者私钥加密无关,

**测试代码如下:**

package com.asymmetric.rsa;
    
    import java.security.InvalidKeyException;
    import java.security.Key;
    import java.security.KeyFactory;
    import java.security.NoSuchAlgorithmException;
    import java.security.PrivateKey;
    import java.security.PublicKey;
    import java.security.spec.InvalidKeySpecException;
    import java.security.spec.PKCS8EncodedKeySpec;
    import java.security.spec.X509EncodedKeySpec;
    import java.util.Base64;
    
    import javax.crypto.BadPaddingException;
    import javax.crypto.Cipher;
    import javax.crypto.IllegalBlockSizeException;
    import javax.crypto.NoSuchPaddingException;
    
    
    
    public class TestRSA {
        
        public static String publicKey = "MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDQgEoj3z9JrdPNI23DbMQkl3gkGuDke7iBr5yrYyqolkTyxuBLWFwHNuGv4VKOj9fXg61QxpaJ/fxDBvMvmkBSRowHBloGFceVTx8wV/8u0DcjvTCu0IZ1zp6wjG6xBn5j66Sg/q+9hvaY2p7fkKmsvcW6VoNPgQHU1Cf01DLZmQIDAQAB+oXcINOiE3AsuZ4VJmwNZg9Y/7fY+OFRS2JAh5YMsrv2qyoGP+Z9ksre26NYR+Lt91B2lhdwJHLpQpziaANZm/ONb31fj/lwIDAQAB";
        public static String privateKey = "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";
        
        private static String algorithm = "RSA"; //$NON-NLS-1$
        
        private static String data = "这是一个test"; //$NON-NLS-1$
        
        public static void main(String[] args) throws NoSuchAlgorithmException, InvalidKeySpecException, NoSuchPaddingException, IllegalBlockSizeException, BadPaddingException, InvalidKeyException {
            byte[] test = testEncrypt(privateKey,data);
            String testDecrypt = testDecrypt(publicKey, test);
            System.out.println(testDecrypt);
        }
        
    
        /**
         * 加密
         * @param key
         * @param data
         * @return
         * @throws NoSuchAlgorithmException
         * @throws InvalidKeySpecException
         * @throws NoSuchPaddingException
         * @throws IllegalBlockSizeException
         * @throws BadPaddingException
         * @throws InvalidKeyException
         */
        public static byte[] testEncrypt(String key,String data) throws NoSuchAlgorithmException, InvalidKeySpecException, NoSuchPaddingException, IllegalBlockSizeException, BadPaddingException, InvalidKeyException{
            byte[] decode = Base64.getDecoder().decode(key);
            PKCS8EncodedKeySpec pkcs8EncodedKeySpec = new PKCS8EncodedKeySpec(decode);
            KeyFactory kf = KeyFactory.getInstance(algorithm);
            PrivateKey generatePrivate = kf.generatePrivate(pkcs8EncodedKeySpec);
            Cipher ci = Cipher.getInstance(algorithm);
            ci.init(1, generatePrivate);
            byte[] doFinal = ci.doFinal(data.getBytes());
    //        return Base64.getEncoder().encodeToString(doFinal);
            return doFinal;
        }
    
        
        /**
         * 解密
         * @param key
         * @param data
         * @return
         * @throws NoSuchAlgorithmException
         * @throws InvalidKeyException 
         * @throws NoSuchPaddingException 
         * @throws InvalidKeySpecException 
         * @throws BadPaddingException 
         * @throws IllegalBlockSizeException 
         */
        public static String testDecrypt(String key,byte[] data) throws NoSuchAlgorithmException, InvalidKeyException, NoSuchPaddingException, InvalidKeySpecException, IllegalBlockSizeException, BadPaddingException{
            byte[] decode = Base64.getDecoder().decode(key);
    //        PKCS8EncodedKeySpec pkcs8EncodedKeySpec = new PKCS8EncodedKeySpec(decode); //java底层 RSA公钥只支持X509EncodedKeySpec这种格式
            X509EncodedKeySpec x509EncodedKeySpec = new X509EncodedKeySpec(decode);
            KeyFactory kf = KeyFactory.getInstance(algorithm);
            PublicKey generatePublic = kf.generatePublic(x509EncodedKeySpec);
            Cipher ci = Cipher.getInstance(algorithm);
            ci.init(1,generatePublic);
    //        byte[] doFinal = ci.doFinal(Base64.getDecoder().decode(data));
            byte[] doFinal = ci.doFinal(Base64.getDecoder().decode(data));
            return Base64.getEncoder().encodeToString(doFinal);
        }
        
    }

**问题点:**

后来发现是解密的时候.cipher.init(1,generatePublic)  cipher 模式填错了,1就代表是加密模式,2是解密模式

将解密方法里的cipher初始化改为 cipher.init(2,generatePublic) 即可

后来看到这个异常用大量数据去测试,也报这个异常,说明rsa加密必须对加密数据进行分组加密

查api指出:`IllegalBlockSizeException` \- 如果此 Cipher 为 Cipher 块，未请求任何填充（只针对加密模式），并且由此 Cipher 处理的数据总输入长度不是块大小的倍数；如果此加密算法无法处理所提供的输入数据。

**修正后的代码:**

package com.asymmetric.rsa;
    
    import java.io.ByteArrayOutputStream;
    import java.io.IOException;
    import java.security.InvalidKeyException;
    import java.security.KeyFactory;
    import java.security.NoSuchAlgorithmException;
    import java.security.PrivateKey;
    import java.security.PublicKey;
    import java.security.spec.InvalidKeySpecException;
    import java.security.spec.PKCS8EncodedKeySpec;
    import java.security.spec.X509EncodedKeySpec;
    import java.util.Base64;
    
    import javax.crypto.BadPaddingException;
    import javax.crypto.Cipher;
    import javax.crypto.IllegalBlockSizeException;
    import javax.crypto.NoSuchPaddingException;
    
    
    
    public class TestRSA {
    	
    	public static String publicKey = "MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDQgEoj3z9JrdPNI23DbMQkl3gkGuDke7iBr5yrYyqolkTyxuBLWFwHNuGv4VKOj9fXg61QxpaJ/fxDBvMvmkBSRowHBloGFceVTx8wV/8u0DcjvTCu0IZ1zp6wjG6xBn5j66Sg/q+9hvaY2p7fkKmsvcW6VoNPgQHU1Cf01DLZmQIDAQAB+oXcINOiE3AsuZ4VJmwNZg9Y/7fY+OFRS2JAh5YMsrv2qyoGP+Z9ksre26NYR+Lt91B2lhdwJHLpQpziaANZm/ONb31fj/lwIDAQAB";
    	public static String privateKey = "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";
    	
    	private static String algorithm = "RSA"; //$NON-NLS-1$
    	private static final int MAX_ENCRYPT_BLOCK = 117;
    	private static final int MAX_DECRYPT_BLOCK = 128;
    	private static String data = "test jiojiogeiojigouihgtest jiojiogeiojigouihgtest jiojiogeiojigouihgtest jiojiogeiojigouihgtest jiojiogeiojigouihgtest jiojiogeiojigouihgtest jiojiogeiojigouihgtest jiojiogeiojigouihgtest jiojiogeiojigouihgtest jiojiogeiojigouihgtest jiojiogeiojigouihgtest jiojiogeiojigouihgtest jiojiogeiojigouihgtest jiojiogeiojigouihgtest jiojiogeiojigouihgtest jiojiogeiojigouihgtest jiojiogeiojigouihg"; //$NON-NLS-1$
    	
    	public static void main(String[] args) throws NoSuchAlgorithmException, InvalidKeySpecException, NoSuchPaddingException, IllegalBlockSizeException, BadPaddingException, InvalidKeyException, IOException {
    		String test = testEncrypt(privateKey,data);
    		String testDecrypt = testDecrypt(publicKey, test);
    		System.out.println(testDecrypt);
    		
    	}
    	
    
    	/**
    	 * 加密
    	 * @param key
    	 * @param data
    	 * @return
    	 * @throws NoSuchAlgorithmException
    	 * @throws InvalidKeySpecException
    	 * @throws NoSuchPaddingException
    	 * @throws IllegalBlockSizeException
    	 * @throws BadPaddingException
    	 * @throws InvalidKeyException
    	 * @throws IOException 
    	 */
    	public static String testEncrypt(String key,String data) throws NoSuchAlgorithmException, InvalidKeySpecException, NoSuchPaddingException, IllegalBlockSizeException, BadPaddingException, InvalidKeyException, IOException{
    		byte[] decode = Base64.getDecoder().decode(key);
    		PKCS8EncodedKeySpec pkcs8EncodedKeySpec = new PKCS8EncodedKeySpec(decode);
    		KeyFactory kf = KeyFactory.getInstance(algorithm);
    		PrivateKey generatePrivate = kf.generatePrivate(pkcs8EncodedKeySpec);
    		Cipher ci = Cipher.getInstance(algorithm);
    		ci.init(Cipher.ENCRYPT_MODE, generatePrivate);
    		
    		byte[] bytes = data.getBytes();
    		int inputLen = bytes.length;
    		int offLen = 0;//偏移量
    		int i = 0;
    		ByteArrayOutputStream bops = new ByteArrayOutputStream();
    		while(inputLen - offLen > 0){
    			byte [] cache;
    			if(inputLen - offLen > 117){
    				cache = ci.doFinal(bytes, offLen,117);
    			}else{
    				cache = ci.doFinal(bytes, offLen,inputLen - offLen);
    			}
    			bops.write(cache);
    			i++;
    			offLen = 117 * i;
    		}
    		bops.close();
    		byte[] encryptedData = bops.toByteArray();
    		String encodeToString = Base64.getEncoder().encodeToString(encryptedData);
    		return encodeToString;
    	}
    	
    
    
    	
    	/**
    	 * 解密
    	 * @param key
    	 * @param data
    	 * @return
    	 * @throws NoSuchAlgorithmException
    	 * @throws InvalidKeyException 
    	 * @throws NoSuchPaddingException 
    	 * @throws InvalidKeySpecException 
    	 * @throws BadPaddingException 
    	 * @throws IllegalBlockSizeException 
    	 * @throws IOException 
    	 */
    	public static String testDecrypt(String key,String data) throws NoSuchAlgorithmException, InvalidKeyException, NoSuchPaddingException, InvalidKeySpecException, IllegalBlockSizeException, BadPaddingException, IOException{
    		byte[] decode = Base64.getDecoder().decode(key);
    //		PKCS8EncodedKeySpec pkcs8EncodedKeySpec = new PKCS8EncodedKeySpec(decode); //java底层 RSA公钥只支持X509EncodedKeySpec这种格式
    		X509EncodedKeySpec x509EncodedKeySpec = new X509EncodedKeySpec(decode);
    		KeyFactory kf = KeyFactory.getInstance(algorithm);
    		PublicKey generatePublic = kf.generatePublic(x509EncodedKeySpec);
    		Cipher ci = Cipher.getInstance(algorithm);
    		ci.init(Cipher.DECRYPT_MODE,generatePublic);
    		
    		byte[] bytes = Base64.getDecoder().decode(data);
    		int inputLen = bytes.length;
    		int offLen = 0;
    		int i = 0;
    		ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
    		while(inputLen - offLen > 0){
    			byte[] cache;
    			if(inputLen - offLen > 128){
    				cache = ci.doFinal(bytes,offLen,128); 
    			}else{
    				cache = ci.doFinal(bytes,offLen,inputLen - offLen);
    			}
    			byteArrayOutputStream.write(cache);
    			i++;
    			offLen = 128 * i;
    			
    		}
    		byteArrayOutputStream.close();
    		byte[] byteArray = byteArrayOutputStream.toByteArray();
    		return new String(byteArray);
    	}
    	
    	
    	
    }