1、整个定义的function
function pkcs1pad2(s,n) {
if(n <s.length + 11) { // TODO: fix for utf-8
alert("Message too long for RSA")
return null
}
var ba = new Array()
var i = s.length - 1
while(i >= 0 &&n >0) {
var c = s.charCodeAt(i--)
//UTF-8编码为变长字节,使用实际的字节来记录
if(c <128) { // encode using utf-8
ba[--n] = c
}
else if((c >127) &&(c <2048)) {
ba[--n] = (c &63) | 128
ba[--n] = (c >>6) | 192
}
else {
ba[--n] = (c &63) | 128
ba[--n] = ((c >>6) &63) | 128
ba[--n] = (c >>12) | 224
}
}
//实际输入拼装结束,将下一位赋值为0标记结束
ba[--n] = 0
var rng = new SecureRandom()
var x = new Array()
//拼接随机非0字节
while(n >2) { // random non-zero pad
x[0] = 0
while(x[0] == 0) rng.nextBytes(x)
ba[--n] = x[0]
}
//这两位做简单的校验
ba[--n] = 2
ba[--n] = 0
return new BigInteger(ba)
}
该方法中对UTF-8字符进行了兼容，并且在拼装完实际输入的字符后，还拼装了随机的字节，使用拼装后的字符串去加密。由于每次拼装的结果是随机的，这样每次加密后的密文都不同。
2、调用方法：；
function RSAEncrypt(text) {
var m = pkcs1pad2(text,(this.n.bitLength()+7)>>3)
if(m == null) return null
var c = this.doPublic(m)
if(c == null) return null
var h = c.toString(16)
if((h.length &1) == 0) return helse return "0" + h
}
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.Base64import 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))
}
}
