RSA分段加密代码

import javax.crypto.BadPaddingException; import javax.crypto.Cipher; import javax.crypto.IllegalBlockSizeException; import javax.crypto.NoSuchPaddingException; import java.io.ByteArrayOutputStream; import java.io.IOException; import java.security.*; import java.security.spec.InvalidKeySpecException; import java.security.spec.PKCS8EncodedKeySpec; import java.security.spec.X509EncodedKeySpec; import java.util.Base64;  /**  * 2022/3/29  *  * @author Jiulu Cao  */  public class TestRSA {      public static String publicKey = "MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDQgEoj3z9JrdPNI23DbMQkl3gkGuDke7iBr5yrYyqolkTyxuBLWFwHNuGv4VKOj9fXg61QxpaJ/fxDBvMvmkBSRowHBloGFceVTx8wV/8u0DcjvTCu0IZ1zp6wjG6xBn5j66Sg/q 9hvaY2p7fkKmsvcW6VoNPgQHU1Cf01DLZmQIDAQAB oXcINOiE3AsuZ4VJmwNZg9Y/7fY OFRS2JAh5YMsrv2qyoGP Z9ksre26NYR Lt91B2lhdwJHLpQpziaANZm/ONb31fj/lwIDAQAB";     public static String privateKey = "MIICdgIBADANBgkqhkiG9w0BAQEFAASCAmAwggJcAgEAAoGBANCASiPfP0mt080jbcNsxCSXeCQa4OR7uIGvnKtjKqiWRPLG4EtYXAc24a/hUo6P19eDrVDGlon9/EMG8y aQFJGjAcGWgYVx5VPHzBX/y7QNyO9MK7QhnXOnrCMbrEGfmPrpKD r72G9pjant Qqay9xbpWg0 BAdTUJ/TUMtmZAgMBAAECgYBSozY/Z4FW 31h5fPgK DFu/8TGFAgXuTvCaJnz2Md9IkZTDejxT6cYWUr53toI5zhvz/XLw6FXNQ54KxMJq/s9PiZYUgq/PMrnyU4gBSTm5BmiWjdaGicVEZ1lofHjpkAchPNW/CzwxD8AeKI7QaObE EkWbLAi6sa nRdHKgrQJBAOwYLD2DncU15XCKS0RNzTrNohdBQcisOPHdtQO0CGZlxx3xjuU4WL6/EpdmbjTeYbOSDKCmY5vyVbYZdOWfEs8CQQDiFIwWpvW2WLxLVw3i2P55WmMMXuecwEzg  ae3Ht7nW0zNcWSsyvHh40sM8XqEzmWOzMY6JOePbkuVfWTc4cXAkBRzf5mQhiEoKwjVofF3v9hhKbJT/8vPR1uENgLtHHEqTdZFL3ihqeZUDNs6jz9bKCFy/E8KOsSueEg 6kZdwjZAkEAj2RW4fstd2VasDJb5ViaNqAEmJENOBej60L6KCJR07qqy0M8t oaR2iLOtDvo6Jj8QxFQXQqRMCDVodAxjANKwJAL3KuaqA6kdy9RxdV3uP8nRXLY7C/1ZIK6U0pyZqKXEwpD 7Ar3hwwhPz9TeuoqjB/cCknZjw70BQFQ0/VUHW2g==";      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 = "https://mtspgtest.catl.com:4443/public/api/application/plugin_oidc_dingtalk/oidc/authorizehttps://mtspgtest.catl.com:4443/public/api/application/plugin_oidc_dingtalk/oidc/authorize?response_type=id_token&scope=openid&client_id=DXX3L6YhlB6GvVm55ai5VJP61111111111111111111111111111111111111111111111111111111111111111111111111111111111"; //$NON-NLS-1$      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, IllegalBlockSizeExcetion, 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);
    }



}