如何用java中的RSA密钥加密解密 [英] How to encrypt decrypt with RSA keys in java

问题描述

我需要用 rsaprivatekey.pem 和 rsapublickey.pem 使用openssl生成的密钥

I need to replace the encrypt and decrypt step from Unix to java code with the rsaprivatekey.pem and rsapublickey.pem keys generated with openssl

我生成密钥

openssl  genrsa  -out /tmp/rsaprivatekey.pem  -des3 1024
openssl rsa -in /tmp/rsaprivatekey.pem -pubout -out /tmp/rsapublickey.pem

我使用unix中的密钥（我需要在java中执行）

i use the keys in unix (i need do it in java)

echo "Text to encript"| openssl rsautl -encrypt -inkey /tmp/rsapublickey.pem -pubin -out out.enc
openssl rsautl -decrypt -inkey /tmp/rsaprivatekey.pem -in out.enc

这是我的尝试

public static void main(String[] args) {


    Base64 base64 = new Base64();

    String TextStream = "this is the input text";
    byte[] Cipher;
    System.out.println("input:\n" + TextStream);
    Cipher = encrypt(TextStream);
    System.out.println("cipher:\n" + base64.encodeAsString(Cipher));
    System.out.println("decrypt:\n" + decrypt(Cipher));
}

private static byte[] encrypt(String Buffer) {
    try {

        Cipher rsa;
        rsa = Cipher.getInstance("RSA");
        rsa.init(Cipher.ENCRYPT_MODE, getPrivateKey(PRIVATE_PATH));
        return rsa.doFinal(Buffer.getBytes());
    } catch (Exception e) {
        e.printStackTrace();
    }
    return null;
}


private static String decrypt(byte[] buffer) {
    try {
        Cipher rsa;
        rsa = Cipher.getInstance("RSA");
        rsa.init(Cipher.DECRYPT_MODE, getPrivateKey(PUBLIC_PATH));
        byte[] utf8 = rsa.doFinal(buffer);
        return new String(utf8, "UTF8");
    } catch (Exception e) {
        e.printStackTrace();
    }
    return null;
}

public static PrivateKey getPrivateKey(String filename) throws Exception {
    File f = new File(filename);
    FileInputStream fis = new FileInputStream(f);
    DataInputStream dis = new DataInputStream(fis);
    byte[] keyBytes = new byte[(int) f.length()];
    dis.readFully(keyBytes);
    dis.close();

    PKCS8EncodedKeySpec spec = new PKCS8EncodedKeySpec(keyBytes);
    KeyFactory kf = KeyFactory.getInstance("RSA");
    return kf.generatePrivate(spec);
}

public static PublicKey getPublicKey(String filename) throws Exception {
    File f = new File(filename);
    FileInputStream fis = new FileInputStream(f);
    DataInputStream dis = new DataInputStream(fis);
    byte[] keyBytes = new byte[(int) f.length()];
    dis.readFully(keyBytes);
    dis.close();

    X509EncodedKeySpec spec = new X509EncodedKeySpec(keyBytes);
    KeyFactory kf = KeyFactory.getInstance("RSA");
    return kf.generatePublic(spec);
}

但它不起作用，PKCS8EncodedKeySpec / X509EncodedKeySpec不正确......但是我不知道该放什么

but it not works, the PKCS8EncodedKeySpec/X509EncodedKeySpec are not correct... but i do not know what to put

推荐答案

我认为你在阅读PEM文件时遇到了问题。 JPA不直接支持PEM格式。您有两个选项，要么将它们转换为DER编码文件（您可以使用openSSL执行此操作），也可以使用bouncy castle API来读取（或写入）PEM文件。您感兴趣的课程称为PEMReader（也可能是PEMWriter）。 这是Javadoc 在bouncycastle网站上。

I think you're having problems reading PEM files. The JPA doesn't directly support the PEM format. You have two options, either convert them to DER encoded files (you can use openSSL to do this) or the you can use the bouncy castle API to read (or write) PEM files. the class you'd be interested in is called PEMReader (and maybe also PEMWriter). Here is the Javadoc on the bouncycastle website.

这篇关于如何用java中的RSA密钥加密解密的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！