RSA签名,加解密处理核心文件

import java.io.ByteArrayOutputStream;

import java.io.UnsupportedEncodingException;

import java.security.InvalidKeyException;

import java.security.Key;

import java.security.KeyFactory;

import java.security.KeyPair;

import java.security.KeyPairGenerator;

import java.security.NoSuchAlgorithmException;

import java.security.PrivateKey;

import java.security.PublicKey;

import java.security.Signature;

import java.security.SignatureException;

import java.security.cert.Certificate;

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.apache.commons.codec.binary.Base64;

/**

*

* <p>RSA签名,加解密处理核心文件，注意：密钥长度1024</p>

* @author leelun

* @version $Id: RSA.java, v 0.1 2013-11-15 下午2:33:53 lilun Exp $

*/

public class RSA {

/**

* 签名算法

*/

public static final String  SIGNATURE_ALGORITHM = "SHA1withRSA";

/**

* 加密算法RSA

*/

public static final String  KEY_ALGORITHM       = "RSA";

/**

* 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;

/**

* 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";

/**

* <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;

}

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

Map<String, Object> genKeyPair = genKeyPair();

String base64publicKey = getPublicKey(genKeyPair);

System.out.println("公钥 \n" + base64publicKey);

String base64privateKey = getPrivateKey(genKeyPair);

System.out.println("私钥\n" + base64privateKey);

String passwd = "cat123113";

String charsetName = "utf-8";

String encryptByPublicKey = Base64.encodeBase64String((encryptByPublicKey(

passwd.getBytes(charsetName), base64publicKey)));

System.out.println("加密\n" + encryptByPublicKey);

byte[] decryptByPrivateKey = decryptByPrivateKey(Base64.decodeBase64(encryptByPublicKey),

base64privateKey);

String string = new String(decryptByPrivateKey, "utf-8");

System.out.println("解密后\n" + string);

}

/**

* 签名字符串

*

* @param text

*            需要签名的字符串

* @param privateKey 私钥(BASE64编码)

*

* @param charset

*            编码格式

* @return 签名结果(BASE64编码)

*/

public static String sign(String text, String privateKey, String charset) throws Exception {

byte[] keyBytes = Base64.decodeBase64(privateKey);

PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);

KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);

PrivateKey privateK = keyFactory.generatePrivate(pkcs8KeySpec);

Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);

signature.initSign(privateK);

signature.update(getContentBytes(text, charset));

byte[] result = signature.sign();

return Base64.encodeBase64String(result);

}

public static String sign(String text, PrivateKey privateKey, String charset)

throws SignatureException,

InvalidKeyException {

try {

Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);

signature.initSign(privateKey);

signature.update(getContentBytes(text, charset));

byte[] result = signature.sign();

return Base64.encodeBase64String(result);

} catch (NoSuchAlgorithmException e) {

//不可能发生，

return null;

}

}

/**

* 签名字符串

*

* @param text

*            需要签名的字符串

* @param sign

*            客户签名结果

* @param publicKey

*            公钥(BASE64编码)

* @param charset

*            编码格式

* @return 验签结果

*/

public static boolean verify(String text, String sign, String publicKey, String charset)

throws Exception {

byte[] keyBytes = Base64.decodeBase64(publicKey);

X509EncodedKeySpec keySpec = new X509EncodedKeySpec(keyBytes);

KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);

PublicKey publicK = keyFactory.generatePublic(keySpec);

Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);

signature.initVerify(publicK);

signature.update(getContentBytes(text, charset));

return signature.verify(Base64.decodeBase64(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 = Base64.decodeBase64(privateKey);

PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);

KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);

Key privateK = keyFactory.generatePrivate(pkcs8KeySpec);

Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());

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 = Base64.decodeBase64(publicKey);

X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes);

KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);

Key publicK = keyFactory.generatePublic(x509KeySpec);

Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());

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 = Base64.decodeBase64(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());

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>

* 公钥加密

* </p>

*

* @param data 源数据

* @param cert 证书

* @return

* @throws Exception

*/

public static byte[] encryptByPublicKey(byte[] data, Certificate cert) throws Exception {

// 对数据加密

PublicKey uk = cert.getPublicKey();

Cipher cipher = Cipher.getInstance(uk.getAlgorithm());

cipher.init(Cipher.ENCRYPT_MODE, uk);

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 = Base64.decodeBase64(privateKey);

PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);

KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);

Key privateK = keyFactory.generatePrivate(pkcs8KeySpec);

Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());

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;

}

/**

* @param content

* @param charset

* @return

* @throws SignatureException

* @throws UnsupportedEncodingException

*/

private static byte[] getContentBytes(String content, String charset) {

if (charset == null || "".equals(charset)) {

return content.getBytes();

}

try {

return content.getBytes(charset);

} catch (UnsupportedEncodingException e) {

throw new RuntimeException("签名过程中出现错误,指定的编码集不对,您目前指定的编码集是:" + charset);

}

}

/**

* <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 Base64.encodeBase64String(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 Base64.encodeBase64String(key.getEncoded());

}

}