「java.rsa」JAVArsa加密

博主:adminadmin 2022-11-22 23:10:05 72

今天给各位分享java.rsa的知识,其中也会对JAVArsa加密进行解释,如果能碰巧解决你现在面临的问题,别忘了关注本站,现在开始吧!

本文目录一览:

关于java中rsa的问题

【实例下载】本文介绍RSA2加密与解密,RSA2是RSA的加强版本,在密钥长度上采用2048, RSA2比RSA更安全,更可靠, 本人的另一篇文章RSA已经发表,有想了解的可以点开下面的RSA文章

Java中RSA的方式如何实现非对称加密的示例

代码如下,需要依赖一个jar包commons-codec-1.9.jar,用于Base64转换,请自行下载。

import org.apache.commons.codec.binary.Base64;

import javax.crypto.BadPaddingException;

import javax.crypto.Cipher;

import javax.crypto.IllegalBlockSizeException;

import java.io.ByteArrayOutputStream;

import java.io.UnsupportedEncodingException;

import java.security.*;

import java.security.interfaces.RSAPrivateKey;

import java.security.interfaces.RSAPublicKey;

import java.security.spec.PKCS8EncodedKeySpec;

import java.security.spec.X509EncodedKeySpec;

public class RSAUtils {

    // 加密方式

    public static final String ALGORITHM = "RSA";

    // 签名算法

    private static final String SIGNATURE_ALGORITHM = "SHA1WithRSA";

    // 创建密钥对初始长度

    private static final int KEY_SIZE = 512;

    // 字符编码格式

    private static final String CHARSET = "UTF-8";

    // RSA最大加密明文大小

    private static final int MAX_ENCRYPT_BLOCK = 117;

    // RSA最大解密密文大小

    private static final int MAX_DECRYPT_BLOCK = 128;

    private KeyFactory keyFactory;

    public RSAUtils() throws NoSuchAlgorithmException {

        keyFactory = KeyFactory.getInstance(ALGORITHM);

    }

    /**

     * 私钥加密

     *

     * @param content    待加密字符串

     * @param privateKey 私钥

     * @return 加密后字符串(BASE64编码)

     */

    public String encryptByPrivateKey(String content, String privateKey) throws Exception {

        String result;

        try (ByteArrayOutputStream out = new ByteArrayOutputStream()) {

            byte[] keyBytes = new Base64().decode(privateKey);

            PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);

            PrivateKey pKey = keyFactory.generatePrivate(pkcs8KeySpec);

            Cipher cipher = Cipher.getInstance(ALGORITHM);

            cipher.init(Cipher.ENCRYPT_MODE, pKey);

            byte[] data = content.getBytes(CHARSET);

            write2Stream(cipher, data, out);

            byte[] resultBytes = out.toByteArray();

            result = Base64.encodeBase64String(resultBytes);

        } catch (Exception e) {

            throw new Exception(e);

        }

        return result;

    }

    /**

     * 公钥解密

     *

     * @param content   已加密字符串(BASE64加密)

     * @param publicKey 公钥

     * @return

     */

    public String decryptByPublicKey(String content, String publicKey) throws Exception {

        String result = "";

        try (ByteArrayOutputStream out = new ByteArrayOutputStream()) {

            byte[] keyBytes = new Base64().decode(publicKey);

            X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes);

            PublicKey pKey = keyFactory.generatePublic(x509KeySpec);

            Cipher cipher = Cipher.getInstance(ALGORITHM);

            cipher.init(Cipher.DECRYPT_MODE, pKey);

            byte[] data = Base64.decodeBase64(content);

            write2Stream(cipher, data, out);

            byte[] resultBytes = out.toByteArray();

            result = new String(resultBytes);

        } catch (Exception e) {

            throw new Exception(e);

        }

        return result;

    }

    /**

     * 公钥加密

     *

     * @param content   待加密字符串

     * @param publicKey 公钥

     * @return 加密后字符串(BASE64编码)

     */

    public String encryptByPublicKey(String content, String publicKey) throws Exception {

        String result = "";

        try (ByteArrayOutputStream out = new ByteArrayOutputStream()) {

            byte[] keyBytes = new Base64().decode(publicKey);

            X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes);

            PublicKey pKey = keyFactory.generatePublic(x509KeySpec);

            Cipher cipher = Cipher.getInstance(ALGORITHM);

            cipher.init(Cipher.ENCRYPT_MODE, pKey);

            byte[] data = content.getBytes(CHARSET);

            write2Stream(cipher,

                    data, out);

            byte[] resultBytes = out.toByteArray();

            result = Base64.encodeBase64String(resultBytes);

        } catch (Exception e) {

            throw new Exception(e);

        }

        return result;

    }

    /**

     * 私钥解密

     *

     * @param content    已加密字符串

     * @param privateKey 私钥

     * @return 解密后字符串

     */

    public String decryptByPrivateKey(String content, String privateKey) throws Exception {

        String result = "";

        try (ByteArrayOutputStream out = new ByteArrayOutputStream()) {

            byte[] keyBytes = new Base64().decode(privateKey);

            PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);

            PrivateKey pKey = keyFactory.generatePrivate(pkcs8KeySpec);

            Cipher cipher = Cipher.getInstance(ALGORITHM);

            cipher.init(Cipher.DECRYPT_MODE, pKey);

            byte[] data = Base64.decodeBase64(content);

            write2Stream(cipher, data, out);

            byte[] resultBytes = out.toByteArray();

            result = new String(resultBytes);

        } catch (Exception e) {

            throw new Exception(e);

        }

        return result;

    }

    private static void write2Stream(Cipher cipher, byte[] data, ByteArrayOutputStream out) throws

            BadPaddingException, IllegalBlockSizeException {

        int dataLen = data.length;

        int offSet = 0;

        byte[] cache;

        int i = 0;

        // 对数据分段解密

        while (dataLen - offSet  0) {

            if (dataLen - offSet  MAX_DECRYPT_BLOCK) {

                cache = cipher.doFinal(data, offSet, MAX_DECRYPT_BLOCK);

            } else {

                cache = cipher.doFinal(data, offSet, dataLen - offSet);

            }

            out.write(cache, 0, cache.length);

            i++;

            offSet = i * MAX_DECRYPT_BLOCK;

        }

    }

    /**

     * 用私钥对信息生成数字签名

     *

     * @param data       已加密数据

     * @param privateKey 私钥(BASE64编码)

     * @return sign

     */

    public String sign(String data, String privateKey) throws Exception {

        String result = "";

        try {

            byte[] keyBytes = new Base64().decode(privateKey);

            PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);

            PrivateKey privateK = keyFactory.generatePrivate(pkcs8KeySpec);

            Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);

            signature.initSign(privateK);

            signature.update(parse2HexStr(data).getBytes(CHARSET));

            result = new Base64().encodeToString(signature.sign());

        } catch (Exception e) {

            throw new Exception(e);

        }

        return result;

    }

    /**

     * 校验数字签名

     *

     * @param data      已加密数据

     * @param publicKey 公钥(BASE64编码)

     * @param sign      数字签名

     * @return

     * @throws Exception

     */

    public boolean verify(String data, String publicKey, String sign) throws Exception {

        boolean result;

        try {

            byte[] keyBytes = new Base64().decode(publicKey);

            X509EncodedKeySpec keySpec = new X509EncodedKeySpec(keyBytes);

            PublicKey publicK = keyFactory.generatePublic(keySpec);

            Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);

            signature.initVerify(publicK);

            signature.update(parse2HexStr(data).getBytes(CHARSET));

            result = signature.verify(new Base64().decode(sign));

        } catch (Exception e) {

            throw new Exception(e);

        }

        return result;

    }

    /**

     * 将二进制转换成16进制

     *

     * @param data

     * @return

     */

    public static String parse2HexStr(String data) throws Exception {

        String result = "";

        try {

            byte[] buf = data.getBytes(CHARSET);

            StringBuffer sb = new StringBuffer();

            for (int i = 0; i  buf.length; i++) {

                String hex = Integer.toHexString(buf[i]  0xFF);

                if (hex.length() == 1) {

                    hex = '0' + hex;

                }

                sb.append(hex.toUpperCase());

            }

            result = sb.toString();

        } catch (UnsupportedEncodingException e) {

            throw new Exception(e);

        }

        return result;

    }

    /**

     * 生成公钥与私钥

     */

    public static void createKey() throws Exception {

        try {

            KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance(ALGORITHM);

            keyPairGenerator.initialize(KEY_SIZE);

            KeyPair keyPair = keyPairGenerator.generateKeyPair();

            RSAPublicKey rsaPublicKey = (RSAPublicKey) keyPair.getPublic();

            RSAPrivateKey rsaPrivateKey = (RSAPrivateKey) keyPair.getPrivate();

            String publicKey = Base64.encodeBase64String(rsaPublicKey.getEncoded());

            String privateKey = Base64.encodeBase64String(rsaPrivateKey.getEncoded());

            System.out.println("publicKey=" + publicKey + "\nprivateKey=" + privateKey);

        } catch (NoSuchAlgorithmException e) {

            throw new Exception(e);

        }

    }

    public static void main(String[] args) throws Exception {

        String PRIVATE_KEY = "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";

        String PUBLIC_KEY = "MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCnmBlx+lc/pviri9dUQ0WjXRweGEHmYKqSRj0UsAXpYLxKB7tv3zbNW5oHyYSPJYa/6Px8vBBQfyPww8i3AnFOGwi7caZIvHnQviiUdlr8mH51ZlhHv96to0lSkX/NfOvKvQndzDH60DzLGOMdE0NBrTn/5zEjGwJbVdlvCfOiHwIDAQAB";

        RSAUtils rsaUtil = new RSAUtils();

        String encryptByPublicKey = rsaUtil.encryptByPublicKey("你好!", PUBLIC_KEY);

        System.out.println(encryptByPublicKey);

        String decryptByPrivateKey = rsaUtil.decryptByPrivateKey(encryptByPublicKey, PRIVATE_KEY);

        System.out.println(decryptByPrivateKey);

        String encryptByPrivateKey = rsaUtil.encryptByPrivateKey("你好!", PRIVATE_KEY);

        System.out.println(encryptByPrivateKey);

        String decryptByPublicKey = rsaUtil.decryptByPublicKey(encryptByPrivateKey, PUBLIC_KEY);

        System.out.println(decryptByPublicKey);

        String sign = rsaUtil.sign("1234", PRIVATE_KEY);

        System.out.println("sign:" + sign);

        System.out.println(rsaUtil.verify("1234", PUBLIC_KEY, sign));

    }

}

Java RSA解密

根据已知的公钥m与e生成PublicKey,然后加密,需要用到bouncycastle这个库,大致代码如下:

// 生成m与e

byte[] mBytes = Hex.decode("C535AD4F...略");

BigInteger m = new BigInteger(1, mBytes);

BigInteger e = BigInteger.valueOf(0x10001);

// 恢复公钥

KeyFactory keyFactory = KeyFactory.getInstance("RSA");

PublicKey publicKey = keyFactory.generatePublic(new RSAPublicKeySpec(m, e));

/* 根据经验,那个JS加密后的密文用Java解出来是反转的字符串,

 * 所以如果想要达到与JS完全一致的效果的话,需要将明文先反转,

 * 即将 "admin" 变成 "nimda"

 */

byte[] data = new StringBuilder("admin").reverse().toString().getBytes();

// 现在可以用publicKey加密了

Cipher cipher = Cipher.getInstance("RSA", new BouncyCastleProvider());

cipher.init(Cipher.ENCRYPT_MODE, publicKey);

byte[] enc = cipher.doFinal(data);

System.out.println(Hex.toHexString(enc));

理论上代码大概是这样。加密结果是:

0d42e0ab31391a536346a1a1af7696e21734ab6004b33f4ce1add778d0c3b8b93141cf0422ef3e086e41d0dcf96c9908e30dd9b993c1eea0d0a392f2ecf4347e5ed7d9b3451796ef04203248536ebca02120a9c3fa520f88ca43ec0df30d2210026ac98e0dcd460bd3bd38b4ddd30a5fe0a0c103a5bd02b2e7eb9ae3a2ddab68

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发布于:2022-11-22,除非注明,否则均为首码项目网原创文章,转载请注明出处。