RSAUtil
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package com.test.utils;import java.io.ByteArrayOutputStream;import java.security.Key;import java.security.KeyFactory;import java.security.KeyPair;import java.security.KeyPairGenerator;import java.security.PrivateKey;import java.security.PublicKey;import java.security.Signature;import java.security.interfaces.RSAPrivateKey;import java.security.interfaces.RSAPublicKey;import java.security.spec.PKCS8EncodedKeySpec;import java.security.spec.X509EncodedKeySpec;import java.util.HashMap;import java.util.Map;import javax.crypto.Cipher;import org.bouncycastle.jce.provider.BouncyCastleProvider;public class RSAUtil { /** */ /** * 加密算法RSA */ public static final String KEY_ALGORITHM = "RSA"; /** */ /** * 签名算法 */ public static final String SIGNATURE_ALGORITHM = "MD5withRSA"; /** */ /** * 获取公钥的key */ private static final String PUBLIC_KEY = "RSAPublicKey"; /** */ /** * 获取私钥的key */ private static final String PRIVATE_KEY = "RSAPrivateKey"; /** */ /** * 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; /** */ /** * <p> * 生成密钥对(公钥和私钥) * </p> * * @return * @throws Exception */ public static Map<String, Object> genKeyPair() throws Exception { KeyPairGenerator keyPairGen = KeyPairGenerator.getInstance(KEY_ALGORITHM); keyPairGen.initialize(1024); KeyPair keyPair = keyPairGen.generateKeyPair(); RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic(); RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate(); Map<String, Object> keyMap = new HashMap<String, Object>(2); keyMap.put(PUBLIC_KEY, publicKey); keyMap.put(PRIVATE_KEY, privateKey); return keyMap; } /** */ /** * <p> * 用私钥对信息生成数字签名 * </p> * * @param data * 已加密数据 * @param privateKey * 私钥(BASE64编码) * * @return * @throws Exception */ public static String sign(byte[] data, String privateKey) throws Exception { byte[] keyBytes = Base64Utils.decode(privateKey); PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes); KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM); PrivateKey privateK = keyFactory.generatePrivate(pkcs8KeySpec); Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM, new BouncyCastleProvider()); signature.initSign(privateK); signature.update(data); return Base64Utils.encode(signature.sign()); } /** */ /** * <p> * 校验数字签名 * </p> * * @param data * 已加密数据 * @param publicKey * 公钥(BASE64编码) * @param sign * 数字签名 * * @return * @throws Exception * */ public static boolean verify(byte[] data, String publicKey, String sign) throws Exception { byte[] keyBytes = Base64Utils.decode(publicKey); X509EncodedKeySpec keySpec = new X509EncodedKeySpec(keyBytes); KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM); PublicKey publicK = keyFactory.generatePublic(keySpec); Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM, new BouncyCastleProvider()); signature.initVerify(publicK); signature.update(data); return signature.verify(Base64Utils.decode(sign)); } /** */ /** * <P> * 私钥解密 * </p> * * @param encryptedData * 已加密数据 * @param privateKey * 私钥(BASE64编码) * @return * @throws Exception */ public static byte[] decryptByPrivateKey(byte[] encryptedData, String privateKey) throws Exception { byte[] keyBytes = Base64Utils.decode(privateKey); PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes); KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM); Key privateK = keyFactory.generatePrivate(pkcs8KeySpec); Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm(), new BouncyCastleProvider()); cipher.init(Cipher.DECRYPT_MODE, privateK); int inputLen = encryptedData.length; ByteArrayOutputStream out = new ByteArrayOutputStream(); int offSet = 0; byte[] cache; int i = 0; // 对数据分段解密 while (inputLen - offSet > 0) { if (inputLen - offSet > MAX_DECRYPT_BLOCK) { cache = cipher.doFinal(encryptedData, offSet, MAX_DECRYPT_BLOCK); } else { cache = cipher.doFinal(encryptedData, offSet, inputLen - offSet); } out.write(cache, 0, cache.length); i++; offSet = i * MAX_DECRYPT_BLOCK; } byte[] decryptedData = out.toByteArray(); out.close(); return decryptedData; } /** */ /** * <p> * 公钥解密 * </p> * * @param encryptedData * 已加密数据 * @param publicKey * 公钥(BASE64编码) * @return * @throws Exception */ public static byte[] decryptByPublicKey(byte[] encryptedData, String publicKey) throws Exception { byte[] keyBytes = Base64Utils.decode(publicKey); X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes); KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM); Key publicK = keyFactory.generatePublic(x509KeySpec); Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm(), new BouncyCastleProvider()); cipher.init(Cipher.DECRYPT_MODE, publicK); int inputLen = encryptedData.length; ByteArrayOutputStream out = new ByteArrayOutputStream(); int offSet = 0; byte[] cache; int i = 0; // 对数据分段解密 while (inputLen - offSet > 0) { if (inputLen - offSet > MAX_DECRYPT_BLOCK) { cache = cipher.doFinal(encryptedData, offSet, MAX_DECRYPT_BLOCK); } else { cache = cipher.doFinal(encryptedData, offSet, inputLen - offSet); } out.write(cache, 0, cache.length); i++; offSet = i * MAX_DECRYPT_BLOCK; } byte[] decryptedData = out.toByteArray(); out.close(); return decryptedData; } /** */ /** * <p> * 公钥加密 * </p> * * @param data * 源数据 * @param publicKey * 公钥(BASE64编码) * @return * @throws Exception */ public static byte[] encryptByPublicKey(byte[] data, String publicKey) throws Exception { byte[] keyBytes = Base64Utils.decode(publicKey); X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes); KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM); Key publicK = keyFactory.generatePublic(x509KeySpec); // 对数据加密 Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm(), new BouncyCastleProvider()); cipher.init(Cipher.ENCRYPT_MODE, publicK); int inputLen = data.length; ByteArrayOutputStream out = new ByteArrayOutputStream(); int offSet = 0; byte[] cache; int i = 0; // 对数据分段加密 while (inputLen - offSet > 0) { if (inputLen - offSet > MAX_ENCRYPT_BLOCK) { cache = cipher.doFinal(data, offSet, MAX_ENCRYPT_BLOCK); } else { cache = cipher.doFinal(data, offSet, inputLen - offSet); } out.write(cache, 0, cache.length); i++; offSet = i * MAX_ENCRYPT_BLOCK; } byte[] encryptedData = out.toByteArray(); out.close(); return encryptedData; } /** */ /** * <p> * 私钥加密 * </p> * * @param data * 源数据 * @param privateKey * 私钥(BASE64编码) * @return * @throws Exception */ public static byte[] encryptByPrivateKey(byte[] data, String privateKey) throws Exception { byte[] keyBytes = Base64Utils.decode(privateKey); PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes); KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM); Key privateK = keyFactory.generatePrivate(pkcs8KeySpec); Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm(), new BouncyCastleProvider()); cipher.init(Cipher.ENCRYPT_MODE, privateK); int inputLen = data.length; ByteArrayOutputStream out = new ByteArrayOutputStream(); int offSet = 0; byte[] cache; int i = 0; // 对数据分段加密 while (inputLen - offSet > 0) { if (inputLen - offSet > MAX_ENCRYPT_BLOCK) { cache = cipher.doFinal(data, offSet, MAX_ENCRYPT_BLOCK); } else { cache = cipher.doFinal(data, offSet, inputLen - offSet); } out.write(cache, 0, cache.length); i++; offSet = i * MAX_ENCRYPT_BLOCK; } byte[] encryptedData = out.toByteArray(); out.close(); return encryptedData; } /** */ /** * <p> * 获取私钥 * </p> * * @param keyMap * 密钥对 * @return * @throws Exception */ public static String getPrivateKey(Map<String, Object> keyMap) throws Exception { Key key = (Key) keyMap.get(PRIVATE_KEY); return Base64Utils.encode(key.getEncoded()); } /** */ /** * <p> * 获取公钥 * </p> * * @param keyMap * 密钥对 * @return * @throws Exception */ public static String getPublicKey(Map<String, Object> keyMap) throws Exception { Key key = (Key) keyMap.get(PUBLIC_KEY); return Base64Utils.encode(key.getEncoded()); }}阅读全文
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