如何在java中使用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 openssl 生成的 rsaprivatekey.pem 和 rsapublickey.pem 密钥替换从 Unix 到 java 代码的加密和解密步骤

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

我在 unix 中使用密钥(我需要在 java 中使用)

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:
" + TextStream);
    Cipher = encrypt(TextStream);
    System.out.println("cipher:
" + base64.encodeAsString(Cipher));
    System.out.println("decrypt:
" + 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

我认为您在读取 ​​PEM 文件时遇到了问题.JPA 不直接支持 PEM 格式.您有两个选择，或者将它们转换为 DER 编码文件(您可以使用 openSSL 来执行此操作)，或者您可以使用充气城堡 API 来读取(或写入)PEM 文件.您感兴趣的类称为 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.

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