概述
信息安全基本概念：
- ECC算法（Elliptic curve cryptography，椭圆曲线密码学）
ECC
椭圆加密算法（）是一种，最初由Koblitz和Miller两人于1985年提出，其数学基础是利用椭圆曲线上的构成Abel加法群上椭圆的计算困难性。
是目前已知的公钥体制中，对每比特所提供加密强度最高的一种体制。在软件注册保护方面起到很大的作用，一般的序列号通常由该算法产生。
ECC算法在jdk1.5后加入支持，目前仅仅只能完成密钥的生成与解析。 如果想要获得ECC算法实现，需要调用硬件完成加密/解密（ECC算法相当耗费资源，如果单纯使用CPU进行加密/解密，效率低下）.
算法分类信息：
| 算法 | 密钥长度 | 默认长度 | 签名长度 | 实现的方 |
| NONEwithECDSA | 112-571 | 256 | 128 | JDK/BC |
| RIPEMD160withECDSA | 同上 | 256 | 160 | BC |
| SHA1withECDSA | ... | 256 | 160 | JDK/BC |
| SHA224withECDSA | ... | 256 | 224 | BC |
| SHA256withECDSA | ... | 256 | 256 | JDK/BC |
| SHA384withECDSA | ... | 256 | 384 | JDK/BC |
| SHA512withECDSA | ... | 256 | 512 | JDK/BC |
签名示例
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.ECPrivateKey; import java.security.interfaces.ECPublicKey; import java.security.spec.PKCS8EncodedKeySpec; import java.security.spec.X509EncodedKeySpec; import com.sun.org.apache.xerces.internal.impl.dv.util.HexBin; public class ECDSA { private static String src = "ecdsa security"; public static void main(String[] args) { jdkECDSA(); } public static void jdkECDSA(){ try { //1.初始化密钥 KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("EC"); keyPairGenerator.initialize(256); KeyPair keyPair = keyPairGenerator.generateKeyPair(); ECPublicKey ecPublicKey = (ECPublicKey)keyPair.getPublic(); ECPrivateKey ecPrivateKey = (ECPrivateKey)keyPair.getPrivate(); //2.执行签名 PKCS8EncodedKeySpec pkcs8EncodedKeySpec = new PKCS8EncodedKeySpec(ecPrivateKey.getEncoded()); KeyFactory keyFactory = KeyFactory.getInstance("EC"); PrivateKey privateKey = keyFactory.generatePrivate(pkcs8EncodedKeySpec); Signature signature = Signature.getInstance("SHA1withECDSA"); signature.initSign(privateKey); signature.update(src.getBytes()); byte[] res = signature.sign(); System.out.println("签名："+HexBin.encode(res)); //3.验证签名 X509EncodedKeySpec x509EncodedKeySpec = new X509EncodedKeySpec(ecPublicKey.getEncoded()); keyFactory = KeyFactory.getInstance("EC"); PublicKey publicKey = keyFactory.generatePublic(x509EncodedKeySpec); signature = Signature.getInstance("SHA1withECDSA"); signature.initVerify(publicKey); signature.update(src.getBytes()); boolean bool = signature.verify(res); System.out.println("验证："+bool); } catch (Exception e) { e.printStackTrace(); } } } 加解密示例代码
package com.jd.order.util.encryption;import java.math.BigInteger;import java.security.Key;import java.security.KeyFactory;import java.security.interfaces.ECPrivateKey;import java.security.interfaces.ECPublicKey;import java.security.spec.ECFieldF2m;import java.security.spec.ECParameterSpec;import java.security.spec.ECPoint;import java.security.spec.ECPrivateKeySpec;import java.security.spec.ECPublicKeySpec;import java.security.spec.EllipticCurve;import java.security.spec.PKCS8EncodedKeySpec;import java.security.spec.X509EncodedKeySpec;import java.util.HashMap;import java.util.Map;import javax.crypto.Cipher;import javax.crypto.NullCipher;import org.apache.commons.codec.binary.Base64;import sun.security.ec.ECKeyFactory;import sun.security.ec.ECPrivateKeyImpl;import sun.security.ec.ECPublicKeyImpl;@SuppressWarnings("restriction")public class ECCCoder { public static final String ALGORITHM = "EC"; private static final String PUBLIC_KEY = "ECCPublicKey"; private static final String PRIVATE_KEY = "ECCPrivateKey"; /** * 解密 * 用私钥解密 * * @param data * @param key * @return * @throws Exception */ public static byte[] decrypt(byte[] data, String key) throws Exception { // 对密钥解密 byte[] keyBytes = decryptBASE64(key); // 取得私钥 PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes); KeyFactory keyFactory = ECKeyFactory.INSTANCE; ECPrivateKey priKey = (ECPrivateKey) keyFactory .generatePrivate(pkcs8KeySpec); ECPrivateKeySpec ecPrivateKeySpec = new ECPrivateKeySpec(priKey.getS(), priKey.getParams()); // 对数据解密 // TODO Chipher不支持EC算法 未能实现 Cipher cipher = new NullCipher(); // Cipher.getInstance(ALGORITHM, keyFactory.getProvider()); cipher.init(Cipher.DECRYPT_MODE, priKey, ecPrivateKeySpec.getParams()); return cipher.doFinal(data); } /** * 加密 * 用公钥加密 * * @param data * @param privateKey * @return * @throws Exception */ public static byte[] encrypt(byte[] data, String privateKey) throws Exception { // 对公钥解密 byte[] keyBytes = decryptBASE64(privateKey); // 取得公钥 X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes); KeyFactory keyFactory = ECKeyFactory.INSTANCE; ECPublicKey pubKey = (ECPublicKey) keyFactory .generatePublic(x509KeySpec); ECPublicKeySpec ecPublicKeySpec = new ECPublicKeySpec(pubKey.getW(), pubKey.getParams()); // 对数据加密 // TODO Chipher不支持EC算法 未能实现 Cipher cipher = new NullCipher(); // Cipher.getInstance(ALGORITHM, keyFactory.getProvider()); cipher.init(Cipher.ENCRYPT_MODE, pubKey, ecPublicKeySpec.getParams()); return cipher.doFinal(data); } /** * 取得私钥 * * @param keyMap * @return * @throws Exception */ public static String getPrivateKey(Map keyMap) throws Exception { Key key = (Key) keyMap.get(PRIVATE_KEY); return encryptBASE64(key.getEncoded()); } /** * 取得公钥 * * @param keyMap * @return * @throws Exception */ public static String getPublicKey(Map keyMap) throws Exception { Key key = (Key) keyMap.get(PUBLIC_KEY); return encryptBASE64(key.getEncoded()); } /** * 初始化密钥 * * @return * @throws Exception */ public static Map initKey() throws Exception { BigInteger x1 = new BigInteger( "2fe13c0537bbc11acaa07d793de4e6d5e5c94eee8", 16); BigInteger x2 = new BigInteger( "289070fb05d38ff58321f2e800536d538ccdaa3d9", 16); ECPoint g = new ECPoint(x1, x2); // the order of generator BigInteger n = new BigInteger( "5846006549323611672814741753598448348329118574063", 10); // the cofactor int h = 2; int m = 163; int[] ks = { 7, 6, 3 }; ECFieldF2m ecField = new ECFieldF2m(m, ks); // y^2+xy=x^3+x^2+1 BigInteger a = new BigInteger("1", 2); BigInteger b = new BigInteger("1", 2); EllipticCurve ellipticCurve = new EllipticCurve(ecField, a, b); ECParameterSpec ecParameterSpec = new ECParameterSpec(ellipticCurve, g, n, h); // 公钥 ECPublicKey publicKey = new ECPublicKeyImpl(g, ecParameterSpec); BigInteger s = new BigInteger( "1234006549323611672814741753598448348329118574063", 10); // 私钥 ECPrivateKey privateKey = new ECPrivateKeyImpl(s, ecParameterSpec); Map keyMap = new HashMap (2); keyMap.put(PUBLIC_KEY, publicKey); keyMap.put(PRIVATE_KEY, privateKey); return keyMap; } public static byte[] decryptBASE64(String data) { return Base64.decodeBase64(data); } public static String encryptBASE64(byte[] data) { return new String(Base64.encodeBase64(data)); }} 请注意上述代码中的TODO内容，再次提醒注意，Chipher不支持EC算法 ，以上代码仅供参考。Chipher、Signature、KeyPairGenerator、KeyAgreement、SecretKey均不支持EC算法。为了确保程序能够正常执行，我们使用了NullCipher类，验证程序。
测试示例
package com.jd.order.util.encryption;import static org.junit.Assert.assertEquals;import java.util.Map;import org.junit.Test;public class ECCCoderTest { @Test public void test() throws Exception { String inputStr = "abc"; byte[] data = inputStr.getBytes(); Map keyMap = ECCCoder.initKey(); String publicKey = ECCCoder.getPublicKey(keyMap); String privateKey = ECCCoder.getPrivateKey(keyMap); System.err.println("公钥: \n" + publicKey); System.err.println("私钥： \n" + privateKey); byte[] encodedData = ECCCoder.encrypt(data, publicKey); byte[] decodedData = ECCCoder.decrypt(encodedData, privateKey); String outputStr = new String(decodedData); System.err.println("加密前: " + inputStr + "\n\r" + "解密后: " + outputStr); assertEquals(inputStr, outputStr); }} 输出
公钥: MEAwEAYHKoZIzj0CAQYFK4EEAAEDLAAEAv4TwFN7vBGsqgfXk95ObV5clO7oAokHD7BdOP9YMh8ugAU21TjM2qPZ私钥： MDICAQAwEAYHKoZIzj0CAQYFK4EEAAEEGzAZAgEBBBTYJsR3BN7TFw7JHcAHFkwNmfil7w==加密前: abc解密后: abc
参考文档
http://snowolf.iteye.com/blog/383412
http://baike.baidu.com/item/%E6%A4%AD%E5%9C%86%E5%8A%A0%E5%AF%86%E7%AE%97%E6%B3%95/10305582?sefr=cr