默认情况下，.NET生成的RSA密钥对可以用XML或字节流来保存，而JAVA中生成的RSA密钥对只能用字节流来保存。而它们的字节流格式不同，就导致Java中生成的RSA密钥对不能在.NET中使用，而.NET中生成的密钥对又不能在Java中使用。而.NET的XML保存方法我觉得比较有通用性，于是就以.NET中RSA密钥保存的XML格式作为兼容格式，这样它们就可以通用了。下面是Java代码：
PS:在Chrome上用博客园的编辑器设置不了代码折叠，保存后折叠的代码就打不开了。。。
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文件：StringHelper.java
字符串操作辅助类
文件：Base64Helper.java
Base64字符串和字节流互转的辅助类
文件：RsaHelper.java
代码中主要方法说明：
KeyPair generateRSAKeyPair();//生成密钥对
String encodePublicKeyToXml(PublicKey key);//将公钥转换为XML字符串
PublicKey decodePublicKeyFromXml(String xml);//从XML字符串得到公钥
String encodePrivateKeyToXml(PrivateKey key);//将私钥转换为XML字符串
PrivateKey decodePrivateKeyFromXml(String xml);//从XML字符串得到私钥
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StringHelper.java
/*
* To change this template, choose Tools | Templates * and open the template in the editor. */ package com.scbeta.helpers; /** * * @author aaa */ public class StringHelper { //数组中是否包括某字符串 public static boolean arrayContainsString(String[] array, String key) { for (String tmpString : array) { if (tmpString.equals(key)) { return true; } } return false; } public static String GetLeftString(String source, String strTail) { return GetLeftString(source, strTail, false); } public static String GetLeftString(String source, String strTail, boolean KeepHeadAndTail) { return GetMiddleString(source, "", strTail, KeepHeadAndTail); } public static String GetRightString(String source, String strHead) { return GetRightString(source, strHead, false); } public static String GetRightString(String source, String strHead, boolean KeepHeadAndTail) { return GetMiddleString(source, strHead, "", KeepHeadAndTail); } public static String GetMiddleString(String source, String strHead, String strTail) { return GetMiddleString(source, strHead, strTail, false); } public static String GetMiddleString(String source, String strHead, String strTail, boolean KeepHeadAndTail) { try { int indexHead, indexTail; if (strHead == null || strHead.isEmpty()) { indexHead = 0; } else { indexHead = source.indexOf(strHead); } if (strTail == null || strTail.isEmpty()) { indexTail = source.length(); } else { indexTail = source.indexOf(strTail, indexHead + strHead.length()); } if (indexTail < 0) { indexTail = source.length(); } String rtnStr = ""; if ((indexHead >= 0) && (indexTail >= 0)) { if (KeepHeadAndTail) { rtnStr = source.substring(indexHead, indexTail + strTail.length()); } else { rtnStr = source.substring(indexHead + strHead.length(), indexTail); } } return rtnStr; } catch (Exception ex) { return ""; } } }
Base64Helper.java:
package com.scbeta.helpers; import java.io.IOException; public class Base64Helper { public static String encode(byte[] byteArray) { sun.misc.BASE64Encoder base64Encoder = new sun.misc.BASE64Encoder(); return base64Encoder.encode(byteArray); } public static byte[] decode(String base64EncodedString) { sun.misc.BASE64Decoder base64Decoder = new sun.misc.BASE64Decoder(); try { return base64Decoder.decodeBuffer(base64EncodedString); } catch (IOException e) { return null; } }
}
RsaHelper.java:
//=================== //作者：aaaSoft //日期：2011年11月30日 //博客：http://www.cnblogs.com/aaaSoft/ //Email：scbeta@qq.com //说明：原创文章，转载请注明出处并保留作者信息 //=================== package com.scbeta.helpers.security; import java.math.BigInteger; 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.interfaces.RSAPrivateCrtKey; import java.security.interfaces.RSAPublicKey; import java.security.spec.RSAPrivateCrtKeySpec; import java.security.spec.RSAPublicKeySpec; import javax.crypto.Cipher; import com.scbeta.helpers.Base64Helper; import com.scbeta.helpers.StringHelper; public class RsaHelper { /** * 生成RSA密钥对(默认密钥长度为1024) * * @return */ public static KeyPair generateRSAKeyPair() { return generateRSAKeyPair(1024); } /** * 生成RSA密钥对 * * @param keyLength * 密钥长度，范围：512～2048 * @return */ public static KeyPair generateRSAKeyPair(int keyLength) { try { KeyPairGenerator kpg = KeyPairGenerator.getInstance("RSA"); kpg.initialize(keyLength); return kpg.genKeyPair(); } catch (NoSuchAlgorithmException e) { return null; } } public static String encodePublicKeyToXml(PublicKey key) { if (!RSAPublicKey.class.isInstance(key)) { return null; } RSAPublicKey pubKey = (RSAPublicKey) key; StringBuilder sb = new StringBuilder(); sb.append("<RSAKeyValue>"); sb.append("<Modulus>") .append(Base64Helper.encode(pubKey.getModulus().toByteArray())) .append("</Modulus>"); sb.append("<Exponent>") .append(Base64Helper.encode(pubKey.getPublicExponent() .toByteArray())).append("</Exponent>"); sb.append("</RSAKeyValue>"); return sb.toString(); } public static PublicKey decodePublicKeyFromXml(String xml) { xml = xml.replaceAll("\r", "").replaceAll("\n", ""); BigInteger modulus = new BigInteger(1, Base64Helper.decode(StringHelper .GetMiddleString(xml, "<Modulus>", "</Modulus>"))); BigInteger publicExponent = new BigInteger(1, Base64Helper.decode(StringHelper.GetMiddleString(xml, "<Exponent>", "</Exponent>"))); RSAPublicKeySpec rsaPubKey = new RSAPublicKeySpec(modulus, publicExponent); KeyFactory keyf; try { keyf = KeyFactory.getInstance("RSA"); return keyf.generatePublic(rsaPubKey); } catch (Exception e) { return null; } } public static PrivateKey decodePrivateKeyFromXml(String xml) { xml = xml.replaceAll("\r", "").replaceAll("\n", ""); BigInteger modulus = new BigInteger(1, Base64Helper.decode(StringHelper .GetMiddleString(xml, "<Modulus>", "</Modulus>"))); BigInteger publicExponent = new BigInteger(1, Base64Helper.decode(StringHelper.GetMiddleString(xml, "<Exponent>", "</Exponent>"))); BigInteger privateExponent = new BigInteger(1, Base64Helper.decode(StringHelper.GetMiddleString(xml, "<D>", "</D>"))); BigInteger primeP = new BigInteger(1, Base64Helper.decode(StringHelper .GetMiddleString(xml, "<P>", "</P>"))); BigInteger primeQ = new BigInteger(1, Base64Helper.decode(StringHelper .GetMiddleString(xml, "<Q>", "</Q>"))); BigInteger primeExponentP = new BigInteger(1, Base64Helper.decode(StringHelper.GetMiddleString(xml, "<DP>", "</DP>"))); BigInteger primeExponentQ = new BigInteger(1, Base64Helper.decode(StringHelper.GetMiddleString(xml, "<DQ>", "</DQ>"))); BigInteger crtCoefficient = new BigInteger(1, Base64Helper.decode(StringHelper.GetMiddleString(xml, "<InverseQ>", "</InverseQ>"))); RSAPrivateCrtKeySpec rsaPriKey = new RSAPrivateCrtKeySpec(modulus, publicExponent, privateExponent, primeP, primeQ, primeExponentP, primeExponentQ, crtCoefficient); KeyFactory keyf; try { keyf = KeyFactory.getInstance("RSA"); return keyf.generatePrivate(rsaPriKey); } catch (Exception e) { return null; } } public static String encodePrivateKeyToXml(PrivateKey key) { if (!RSAPrivateCrtKey.class.isInstance(key)) { return null; } RSAPrivateCrtKey priKey = (RSAPrivateCrtKey) key; StringBuilder sb = new StringBuilder(); sb.append("<RSAKeyValue>"); sb.append("<Modulus>") .append(Base64Helper.encode(priKey.getModulus().toByteArray())) .append("</Modulus>"); sb.append("<Exponent>") .append(Base64Helper.encode(priKey.getPublicExponent() .toByteArray())).append("</Exponent>"); sb.append("<P>") .append(Base64Helper.encode(priKey.getPrimeP().toByteArray())) .append("</P>"); sb.append("<Q>") .append(Base64Helper.encode(priKey.getPrimeQ().toByteArray())) .append("</Q>"); sb.append("<DP>") .append(Base64Helper.encode(priKey.getPrimeExponentP() .toByteArray())).append("</DP>"); sb.append("<DQ>") .append(Base64Helper.encode(priKey.getPrimeExponentQ() .toByteArray())).append("</DQ>"); sb.append("<InverseQ>") .append(Base64Helper.encode(priKey.getCrtCoefficient() .toByteArray())).append("</InverseQ>"); sb.append("<D>") .append(Base64Helper.encode(priKey.getPrivateExponent() .toByteArray())).append("</D>"); sb.append("</RSAKeyValue>"); return sb.toString(); } // 用公钥加密 public static byte[] encryptData(byte[] data, PublicKey pubKey) { try { Cipher cipher = Cipher.getInstance("RSA"); cipher.init(Cipher.ENCRYPT_MODE, pubKey); return cipher.doFinal(data); } catch (Exception e) { return null; } } // 用私钥解密 public static byte[] decryptData(byte[] encryptedData, PrivateKey priKey) { try { Cipher cipher = Cipher.getInstance("RSA"); cipher.init(Cipher.DECRYPT_MODE, priKey); return cipher.doFinal(encryptedData); } catch (Exception e) { return null; } } /** * 根据指定私钥对数据进行签名(默认签名算法为"SHA1withRSA") * * @param data * 要签名的数据 * @param priKey * 私钥 * @return */ public static byte[] signData(byte[] data, PrivateKey priKey) { return signData(data, priKey, "SHA1withRSA"); } /** * 根据指定私钥和算法对数据进行签名 * * @param data * 要签名的数据 * @param priKey * 私钥 * @param algorithm * 签名算法 * @return */ public static byte[] signData(byte[] data, PrivateKey priKey, String algorithm) { try { Signature signature = Signature.getInstance(algorithm); signature.initSign(priKey); signature.update(data); return signature.sign(); } catch (Exception ex) { return null; } } /** * 用指定的公钥进行签名验证(默认签名算法为"SHA1withRSA") * * @param data * 数据 * @param sign * 签名结果 * @param pubKey * 公钥 * @return */ public static boolean verifySign(byte[] data, byte[] sign, PublicKey pubKey) { return verifySign(data, sign, pubKey, "SHA1withRSA"); } /** * * @param data 数据 * @param sign 签名结果 * @param pubKey 公钥 * @param algorithm 签名算法 * @return */ public static boolean verifySign(byte[] data, byte[] sign, PublicKey pubKey, String algorithm) { try { Signature signature = Signature.getInstance(algorithm); signature.initVerify(pubKey); signature.update(data); return signature.verify(sign); } catch (Exception ex) { return false; } } }
==============================
下面是测试代码：
public static void main(String[] args) { KeyPair kp = RsaHelper.generateRSAKeyPair(); PublicKey pubKey = kp.getPublic(); PrivateKey priKey = kp.getPrivate(); String pubKeyXml = RsaHelper.encodePublicKeyToXml(pubKey); String priKeyXml = RsaHelper.encodePrivateKeyToXml(priKey); System.out.println("====公钥===="); System.out.println(pubKeyXml); System.out.println("====私钥===="); System.out.println(priKeyXml); PublicKey pubKey2 = RsaHelper.decodePublicKeyFromXml(pubKeyXml); PrivateKey priKey2 = RsaHelper.decodePrivateKeyFromXml(priKeyXml); System.out.println("====公钥对比===="); System.out.println(pubKey.toString()); System.out.println("------"); System.out.println(pubKey2.toString()); System.out.println("====私钥对比===="); System.out.println(priKey.toString()); System.out.println("------"); System.out.println(priKey2.toString()); try { String pubKeyXml3 = "<RSAKeyValue><Modulus>rHESyuI3ny4MLsqDBalW9ySaodCL0e6Bsrl01Q5G1qm2wjUoGULazZSNqZY+JQNjU92tW3Snk5RPIkv+wDj+uOT9LTUjQImltHnzqMvbt06GipVXDOyBLTa7G/zRIe/CrjyJ+XEYX2xIhpe5ayowl3HHUpZ71jRNioyxaVVZ8S0=</Modulus><Exponent>AQAB</Exponent></RSAKeyValue>"; String priKeyXml3 = "<RSAKeyValue><Modulus>rHESyuI3ny4MLsqDBalW9ySaodCL0e6Bsrl01Q5G1qm2wjUoGULazZSNqZY+JQNjU92tW3Snk5RPIkv+wDj+uOT9LTUjQImltHnzqMvbt06GipVXDOyBLTa7G/zRIe/CrjyJ+XEYX2xIhpe5ayowl3HHUpZ71jRNioyxaVVZ8S0=</Modulus><Exponent>AQAB</Exponent><P>5a7uM+IeY8QMVQl0q88ZTqWbB555l7+366cUIClTN8z2ZXzTnWFCNoQzUrG14FouJFYumFZD12Ni5MkJK6gqSw==</P><Q>wDMhwwO4kz82uSG+FlCBr06fYk2COTg0TofmSp/5OrVqgkBIe7FgpTpVGzGLk0mvOLcy6UZftq//W0Saow6nZw==</Q><DP>FbjDgliiMyE5YVlxlUYSyKNU1BWivj09caXte1UtL5vMubBiewHVtz4tdGamIr+kmX8lDPcrl1Uo5yY0HdLbnQ==</DP><DQ>kIjjJsgxkWnEOUyKqjU4kSDK8x3ehDEkBLpmEFBlGCU9R14YJAyr5RUM0zpbABQ1VK1P9+UYLUYE/hmFQIHQmQ==</DQ><InverseQ>pxQDThwSnUZ4EaNaCPl1ovYypdQUZaZ/Sld1+0n8FEjkmRcGP1R9VMuj1ViPZg3rvm2GeP8Xv1SJqJUVueWiGA==</InverseQ><D>DxBNoPWEAF7IZ6n/KhZx52MGMw6BuFQKdm9m+lml7Iik03BLUXGapYzNlzvtr9QM8D2UMEIPhX/WLdvPpEEWVzGnD7XpLXjGwfu1ZkJRcXPEZEZ2subh5ZBqOWCFWKv5WwgGYWuYDLHfrBlBgSFWR8cZuyqkmMsWl4CiadXqGA0=</D></RSAKeyValue>"; System.out.println((new Date()).toLocaleString() + ": 加载公钥中。。。"); PublicKey pubKey3 = RsaHelper.decodePublicKeyFromXml(pubKeyXml3); System.out.println((new Date()).toLocaleString() + ": 加载私钥中。。。"); PrivateKey priKey3 = RsaHelper.decodePrivateKeyFromXml(priKeyXml3); String dataStr = "Java与.NET和平共处万岁！"; byte[] dataByteArray = dataStr.getBytes("utf-8"); System.out.println("data的Base64表示：" + Base64Helper.encode(dataByteArray)); System.out.println((new Date()).toLocaleString() + ": 加密中。。。"); // 加密 byte[] encryptedDataByteArray = RsaHelper.encryptData( dataByteArray, pubKey3); System.out.println("encryptedData的Base64表示：" + Base64Helper.encode(encryptedDataByteArray)); System.out.println((new Date()).toLocaleString() + ": 解密中。。。"); // 解密 // byte[] byte[] decryptedDataByteArray = RsaHelper.decryptData( encryptedDataByteArray, priKey3); System.out.println(new String(decryptedDataByteArray, "utf-8"));// 签名 System.out.println((new Date()).toLocaleString() + ": 签名中。。。"); byte[] signDataByteArray = RsaHelper.signData(dataByteArray, priKey3); System.out.println("signData的Base64表示：" + Base64Helper.encode(signDataByteArray)); // 验签 System.out.println((new Date()).toLocaleString() + ": 验签中。。。"); boolean isMatch = RsaHelper.verifySign(dataByteArray, signDataByteArray, pubKey3); System.out.println("验签结果：" + isMatch); } catch (Exception ex) { ex.printStackTrace(); } }
最后，补充一段C#产生密钥对的代码片段如下：
using System.Security.Cryptography;//密钥位数int keySize = 1024;//产生密钥对RSACryptoServiceProvider rSACryptoServiceProvider = new RSACryptoServiceProvider(keySize);//得到公钥String publicKey = rSACryptoServiceProvider.ToXmlString(false);//得到私钥String privateKey = rSACryptoServiceProvider.ToXmlString(true);