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javarsa加密,JAVArsa加密

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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里面RSA加密算法的使用

RSA的Java实现不能一次加密很大的字符,自己处理了一下,见下面的代码。Base64编码类用的是一个Public domain Base64 for java 其他的保存公钥到文件等简单的实现,就不详细说了,看代码吧。==============================================import java.security.*;import java.security.spec.PKCS8EncodedKeySpec;import java.security.spec.X509EncodedKeySpec;import java.util.HashMap;import java.util.Map;import javax.crypto.*;import java.io.*;public class Encryptor {private static final String KEY_FILENAME = "c:\\mykey.dat";private static final String OTHERS_KEY_FILENAME = "c:\\Otherskey.dat";// private static final int KEY_SIZE = 1024;// private static final int BLOCK_SIZE = 117;// private static final int OUTPUT_BLOCK_SIZE = 128;private static final int KEY_SIZE = 2048; //RSA key 是多少位的private static final int BLOCK_SIZE = 245; //一次RSA加密操作所允许的最大长度//这个值与 KEY_SIZE 已经padding方法有关。因为 1024的key的输出是128,2048key输出是256字节//可能11个字节用于保存padding信息了,所以最多可用的就只有245字节了。private static final int OUTPUT_BLOCK_SIZE = 256;private SecureRandom secrand;private Cipher rsaCipher;private KeyPair keys;private MapString, Key allUserKeys;public Encryptor() throws Exception {try {allUserKeys = new HashMapString, Key();secrand = new SecureRandom();//SunJCE Provider 中只支持ECB mode,试了一下只有PKCS1PADDING可以直接还原原始数据,//NOPadding导致解压出来的都是blocksize长度的数据,还要自己处理//参见 另外根据 Open-JDK-6.b17-src( )// 中代码的注释,使用RSA来加密大量数据不是一种标准的用法。所以现有实现一次doFinal调用之进行一个RSA操作,//如果用doFinal来加密超过的一个操作所允许的长度数据将抛出异常。//根据keysize的长度,典型的1024个长度的key和PKCS1PADDING一起使用时//一次doFinal调用只能加密117个byte的数据。(NOPadding 和1024 keysize时128个字节长度)//(2048长度的key和PKCS1PADDING 最多允许245字节一次)//想用来加密大量数据的只能自己用其他办法实现了。可能RSA加密速度比较慢吧,要用AES才行rsaCipher = Cipher.getInstance("RSA/ECB/PKCS1PADDING");} catch (NoSuchAlgorithmException e) {e.printStackTrace();} catch (NoSuchPaddingException e) {e.printStackTrace();throw e;}ObjectInputStream in;try {in = new ObjectInputStream(new FileInputStream(KEY_FILENAME));} catch (FileNotFoundException e) {if (false == GenerateKeys()){throw e;}LoadKeys();return;}keys = (KeyPair) in.readObject();in.close();LoadKeys();}/** 生成自己的公钥和私钥*/private Boolean GenerateKeys() {try {KeyPairGenerator keygen = KeyPairGenerator.getInstance("RSA");// secrand = new SecureRandom();// sedSeed之后会造成 生成的密钥都是一样的// secrand.setSeed("chatencrptor".getBytes()); // 初始化随机产生器//key长度至少512长度,不过好像说现在用2048才算比较安全的了keygen.initialize(KEY_SIZE, secrand); // 初始化密钥生成器keys = keygen.generateKeyPair(); // 生成密钥组AddKey("me", EncodeKey(keys.getPublic()));} catch (NoSuchAlgorithmException e) {e.printStackTrace();return false;}ObjectOutputStream out;try {out = new ObjectOutputStream(new FileOutputStream(KEY_FILENAME));} catch (IOException e) {e.printStackTrace();return false;}try {out.writeObject(keys);} catch (IOException e) {e.printStackTrace();return false;} finally {try {out.close();} catch (IOException e) {e.printStackTrace();return false;}}return true;}public String EncryptMessage(String toUser, String Message) throws IOException {Key pubkey = allUserKeys.get(toUser);if ( pubkey == null ){throw new IOException("NoKeyForThisUser") ;}try {//PublicKey pubkey = keys.getPublic();rsaCipher.init(Cipher.ENCRYPT_MODE, pubkey, secrand);//System.out.println(rsaCipher.getBlockSize()); 返回0,非block 加密算法来的?//System.out.println(Message.getBytes("utf-8").length);//byte[] encryptedData = rsaCipher.doFinal(Message.getBytes("utf-8"));byte[] data = Message.getBytes("utf-8");int blocks = data.length / BLOCK_SIZE ;int lastBlockSize = data.length % BLOCK_SIZE ;byte [] encryptedData = new byte[ (lastBlockSize == 0 ? blocks : blocks + 1)* OUTPUT_BLOCK_SIZE];for (int i=0; i blocks; i++){//int thisBlockSize = ( i + 1 ) * BLOCK_SIZE data.length ? data.length - i * BLOCK_SIZE : BLOCK_SIZE ;rsaCipher.doFinal(data,i * BLOCK_SIZE, BLOCK_SIZE, encryptedData ,i * OUTPUT_BLOCK_SIZE);}if (lastBlockSize != 0 ){rsaCipher.doFinal(data, blocks * BLOCK_SIZE, lastBlockSize,encryptedData ,blocks * OUTPUT_BLOCK_SIZE);}//System.out.println(encrypted.length); 如果要机密的数据不足128/256字节,加密后补全成为变为256长度的。//数量比较小时,Base64.GZIP产生的长度更长,没什么优势//System.out.println(Base64.encodeBytes(encrypted,Base64.GZIP).length());//System.out.println(Base64.encodeBytes(encrypted).length());//System.out.println (rsaCipher.getOutputSize(30));//这个getOutputSize 只对 输入小于最大的block时才能得到正确的结果。其实就是补全 数据为128/256 字节return Base64.encodeBytes(encryptedData);} catch (InvalidKeyException e) {e.printStackTrace();throw new IOException("InvalidKey") ;}catch (ShortBufferException e) {e.printStackTrace();throw new IOException("ShortBuffer") ;}catch (UnsupportedEncodingException e) {e.printStackTrace();throw new IOException("UnsupportedEncoding") ;} catch (IllegalBlockSizeException e) {e.printStackTrace();throw new IOException("IllegalBlockSize") ;} catch (BadPaddingException e) {e.printStackTrace();throw new IOException("BadPadding") ;}finally {//catch 中 return 或者throw之前都会先调用一下这里}}public String DecryptMessage(String Message) throws IOException {byte[] decoded = Base64.decode(Message);PrivateKey prikey = keys.getPrivate();try {rsaCipher.init(Cipher.DECRYPT_MODE, prikey, secrand);int blocks = decoded.length / OUTPUT_BLOCK_SIZE;ByteArrayOutputStream decodedStream = new ByteArrayOutputStream(decoded.length);for (int i =0 ;i blocks ; i ++ ){decodedStream.write (rsaCipher.doFinal(decoded,i * OUTPUT_BLOCK_SIZE, OUTPUT_BLOCK_SIZE));}return new String(decodedStream.toByteArray(), "UTF-8");} catch (InvalidKeyException e) {e.printStackTrace();throw new IOException("InvalidKey");} catch (UnsupportedEncodingException e) {e.printStackTrace();throw new IOException("UnsupportedEncoding");} catch (IllegalBlockSizeException e) {e.printStackTrace();throw new IOException("IllegalBlockSize");} catch (BadPaddingException e) {e.printStackTrace();throw new IOException("BadPadding");} finally {// catch 中 return 或者throw之前都会先调用一下这里。}}public boolean AddKey(String user, String key) {PublicKey publickey;try {publickey = DecodePublicKey(key);} catch (Exception e) {return false;}allUserKeys.put(user, publickey);SaveKeys();return true;}private boolean LoadKeys() {BufferedReader input;try {input = new BufferedReader(new InputStreamReader(new FileInputStream(OTHERS_KEY_FILENAME)));} catch (FileNotFoundException e1) {// e1.printStackTrace();return false;}

JAVA写RSA加密,公钥私钥都是一样的,为什么每次加密的结果不一样

因为rsa是非对称加密,它使用的是随机大素数的抽取,每次随机生成的,所以每次加密的结果不可能一样

javarsa加密c#解密失败

系统bug。当软件javarsa的系统出现系统bug时,就会导致该软件在解密c井的程序的时候出现解密失败的情况,只需要将该软件卸载后重新安装该软件即可。