I want to encode a string with rsa/ecb/pkcs1 padding mode with a given public key (the public key is a string) in java.

我想在Java中用rsa/ecb/pkcs1填充模式用给定的公钥(公钥是一个字符串)来编码一个字符串。

I also want to present the results in UTF-8 Format
how to do it?

我也想用UTF-8格式呈现成绩，怎么办呢？

i have done this code:

我已经完成了以下代码：

        String pub = "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";

        KeyFactory keyFactory = KeyFactory.getInstance("RSA");
        byte[] keyBytes = Base64.getDecoder().decode(pub.getBytes("UTF-8"));  
        PKCS1EncodedKeySpec KeySpec = new PKCS1EncodedKeySpec(keyBytes);
        RSAPublicKey publicKey = (RSAPublicKey)keyFactory.generatePublic((java.security.spec.KeySpec) KeySpec);

        Cipher cipher = Cipher.getInstance("RSA/ECB/PKCS1Padding");
        cipher.init(Cipher.ENCRYPT_MODE, publicKey);

        byte[] cipherData = cipher.doFinal(text.getBytes("UTF-8"));


        return cipherData;

But it doesnot work..
it is said that Invalid DER: object is not integer

但它不工作..这就是说，无效DER：对象不是整数

For someone still looking for a solution:

对于仍在寻找解决方案的人：

String pub = "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";
Cipher cipher= Cipher.getInstance("RSA");
KeyFactory kf = KeyFactory.getInstance("RSA");
X509EncodedKeySpec keySpec = new X509EncodedKeySpec(Base64.getDecoder().decode(publicKey));
PublicKey pb = kf.generatePublic(keySpec);
cipher.init(Cipher.ENCRYPT_MODE,pb);
byte[] output = cipher.doFinal(input.getBytes());

Assuming you're using a valid RSA key, you'll need to:

假设您使用的是有效的RSA密钥，您需要：

1. Convert your public key from a string to an actual public key object

   
   
   

   //This code is incorrect. You'll need bouncy castle for PKCS1
   KeyFactory keyFactory = KeyFactory.getInstance("RSA");
   byte[] keyBytes = Base64().getDecoder.decode(publicKey.getBytes()); //assuming base64 encoded key
   PKCS1EncodedKeySpec KeySpec = new PKCS1EncodedKeySpec(keyBytes);
   RSAPublicKey publicKey = (RSAPublicKey)keyFactory.generatePublic(KeySpec);
   




2. Get the bytes of your plain text



3. Encrypt using your public key


4. Encode to a readable format.

Check out this answer for steps 1-3: RSA Encrypt/Decrypt in Java. Remember to use the correct algorithm spec, in your case PKCS1

请查看步骤1-3：Java中的RSA加密/解密的答案。记住使用正确的算法规范，在您的例子中是PKCS1

Chances are your cipher text will not use only UTF-8 characters so you'll probably want to use Base 64 encoded text to display your cipher text. Base 64 is able to display all those wonky characters as ascii values.

您的密文可能不会只使用UTF-8字符，因此您可能希望使用Base64编码的文本来显示密文。BASE 64能够将所有这些不可靠的字符显示为ASCII值。

Simply use: Base64.getEncoder().encodeToString(cipherTextBytes)

只需使用：Base64.getEncoder().encodeToString(cipherTextBytes)