一、前言
很大程度上参考：/chaijunkun/article/details/7275632
在此基础上添加了签名和验证方法。为了完整性，把其前面的内容也搬过来了。
二、openssl下载
windows版本下载地址：/products/Win32OpenSSL.html绿色版下载地址：/projects/openssl/?source=directory
三、openssl使用
绿色版bin目录下openssl.exe打开运行，有个warning，可以不用理会。
下面命令不需要打开头的“openssl”
生成私钥：openssl genrsa -out rsa_private_key.pem 1024保存在当前文件夹下的rsa_private_key.pem文件中，以下同理。根据私钥生成公钥：openssl rsa -in rsa_private_key.pem -out rsa_public_key.pem -pubout此时的私钥还不能直接被java使用（但可以被openssl使用），需要进行PKCS#8编码：openssl pkcs8 -topk8 -in rsa_private_key.pem -out pkcs8_rsa_private_key.pem -nocryptopenssl生成签名文件：因为java端签名验证使用sha1算法做摘要。故openssl使用sha1签名：openssl sha1 -sign rsa_private_key.pem -out rsasign.bin tos.txttos.txt为自己创建的需要签名的文本，里面可以随意写点字符。为了和后面代码匹配文本内容为：helloadsfdsfaasdfasffffffffffffdsafdasfasdfsafzxvxzvasfs
四、代码参考—— jdk1.5
cipher= Cipher.getInstance("RSA", new BouncyCastleProvider());
改为
cipher = Cipher.getInstance("RSA");
本机运行时，起初加解密太慢，去掉BouncyCastleProvider后速度明显提升。而且加密结果一致，不明所以啊（可能和jdk版本有关）。
DEFAULT_PUBLIC_KEY 为rsa_public_key.pem内容。（去掉空格和换行符，头尾的—–PUBLIC KEY—–）
DEFAULT_PRIVATE_KEY 内容为pkcs8_rsa_private_key.pem的内容，格式处理同上。
package com.haiyisoft.lwsp.dto.login;import java.io.File;import java.io.FileInputStream;import java.io.IOException;import java.io.InputStream;import java.security.InvalidKeyException;import java.security.KeyFactory;import java.security.KeyPair;import java.security.KeyPairGenerator;import java.security.NoSuchAlgorithmException;import java.security.SecureRandom;import java.security.Signature;import java.security.SignatureException;import java.security.interfaces.RSAPrivateKey;import java.security.interfaces.RSAPublicKey;import java.security.spec.InvalidKeySpecException;import java.security.spec.PKCS8EncodedKeySpec;import java.security.spec.X509EncodedKeySpec;import java.util.Date;import javax.crypto.BadPaddingException;import javax.crypto.Cipher;import javax.crypto.IllegalBlockSizeException;import javax.crypto.NoSuchPaddingException;import sun.misc.BASE64Decoder;/*** 生成私钥：openssl genrsa -out rsa_private_key.pem 1024 * 根据私钥生成公钥：openssl rsa -in rsa_private_key.pem -out rsa_public_key.pem -pubout* 私钥还不能直接被使用，需要进行PKCS#8编码：openssl pkcs8 -topk8 -in rsa_private_key.pem -out pkcs8_rsa_private_key.pem -nocrypt * sha1签名 openssl sha1 -sign rsa_private_key.pem -out rsasign.bin tos.txt * pkcs8_rsa_private_key 私钥* java可以使用*/public class RsaEncrypt {// openssl 产生的钥 私钥为pkcs8形式private final String DEFAULT_PUBLIC_KEY = "MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCxrbbBo9Zkd4uQ16/cx0LJwUJpUHAYHRnSwM8uPgoRkPEXXRFR9sWvZ3WAFdjSB/3KSd8LAK34P8sq49BouUxCJw0h6o2uv0wKIy70k3mTc4KVF12iClPfZR1fQ3FmJrOPr35AiuZTz+YsMp24WageIVz3VZ7qYmzMZ8dH0Ez+ZQIDAQAB";private final String DEFAULT_PRIVATE_KEY = "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";/*** rsa签名* * @param content* 待签名的字符串* @param privateKey* rsa私钥字符串* @param charset* 字符编码* @return 签名结果* @throws Exception* 签名失败则抛出异常*/public byte[] rsaSign(String content, RSAPrivateKey priKey)throws SignatureException {try {Signature signature = Signature.getInstance("SHA1withRSA");signature.initSign(priKey);signature.update(content.getBytes("utf-8"));byte[] signed = signature.sign();return signed;} catch (Exception e) {throw new SignatureException("RSAcontent = " + content+ "; charset = ", e);}}/*** rsa验签* * @param content* 被签名的内容* @param sign* 签名后的结果* @param publicKey* rsa公钥* @param charset* 字符集* @return 验签结果* @throws SignatureException* 验签失败，则抛异常*/boolean doCheck(String content, byte[] sign, RSAPublicKey pubKey)throws SignatureException {try {Signature signature = Signature.getInstance("SHA1withRSA");signature.initVerify(pubKey);signature.update(content.getBytes("utf-8"));return signature.verify((sign));} catch (Exception e) {throw new SignatureException("RSA验证签名[content = " + content+ "; charset = " + "; signature = " + sign + "]发生异常!", e);}}/*** 私钥*/private RSAPrivateKey privateKey;/*** 公钥*/private RSAPublicKey publicKey;/*** 字节数据转字符串专用集合*/private static final char[] HEX_CHAR = { '0', '1', '2', '3', '4', '5', '6','7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' };/*** 获取私钥* * @return 当前的私钥对象*/public RSAPrivateKey getPrivateKey() {return privateKey;}/*** 获取公钥* * @return 当前的公钥对象*/public RSAPublicKey getPublicKey() {return publicKey;}/*** 随机生成密钥对*/public void genKeyPair() {KeyPairGenerator keyPairGen = null;try {keyPairGen = KeyPairGenerator.getInstance("RSA");} catch (NoSuchAlgorithmException e) {e.printStackTrace();}keyPairGen.initialize(1024, new SecureRandom());KeyPair keyPair = keyPairGen.generateKeyPair();this.privateKey = (RSAPrivateKey) keyPair.getPrivate();this.publicKey = (RSAPublicKey) keyPair.getPublic();}/*** 从字符串中加载公钥* * @param publicKeyStr* 公钥数据字符串* @throws Exception* 加载公钥时产生的异常*/public void loadPublicKey(String publicKeyStr) throws Exception {try {BASE64Decoder base64Decoder = new BASE64Decoder();byte[] buffer = base64Decoder.decodeBuffer(publicKeyStr);KeyFactory keyFactory = KeyFactory.getInstance("RSA");X509EncodedKeySpec keySpec = new X509EncodedKeySpec(buffer);this.publicKey = (RSAPublicKey) keyFactory.generatePublic(keySpec);} catch (NoSuchAlgorithmException e) {throw new Exception("无此算法");} catch (InvalidKeySpecException e) {throw new Exception("公钥非法");} catch (IOException e) {throw new Exception("公钥数据内容读取错误");} catch (NullPointerException e) {throw new Exception("公钥数据为空");}}/*** 加载私钥* * @param keyFileName* 私钥文件名* @return 是否成功* @throws Exception*/public void loadPrivateKey(String privateKeyStr) throws Exception {try {BASE64Decoder base64Decoder = new BASE64Decoder();byte[] buffer = base64Decoder.decodeBuffer(privateKeyStr);PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(buffer);KeyFactory keyFactory = KeyFactory.getInstance("RSA");this.privateKey = (RSAPrivateKey) keyFactory.generatePrivate(keySpec);} catch (NoSuchAlgorithmException e) {throw new Exception("无此算法");} catch (InvalidKeySpecException e) {throw new Exception("私钥非法");} catch (IOException e) {throw new Exception("私钥数据内容读取错误");} catch (NullPointerException e) {throw new Exception("私钥数据为空");}}/*** 加密过程* * @param publicKey* 公钥* @param plainTextData* 明文数据* @return* @throws Exception* 加密过程中的异常信息*/public byte[] encrypt(RSAPublicKey publicKey, byte[] plainTextData)throws Exception {if (publicKey == null) {throw new Exception("加密公钥为空, 请设置");}Cipher cipher = null;try {cipher = Cipher.getInstance("RSA");cipher.init(Cipher.ENCRYPT_MODE, publicKey);byte[] output = cipher.doFinal(plainTextData);return output;} catch (NoSuchAlgorithmException e) {throw new Exception("无此加密算法");} catch (NoSuchPaddingException e) {e.printStackTrace();return null;} catch (InvalidKeyException e) {throw new Exception("加密公钥非法,请检查");} catch (IllegalBlockSizeException e) {throw new Exception("明文长度非法");} catch (BadPaddingException e) {throw new Exception("明文数据已损坏");}}/*** 解密过程* * @param privateKey* 私钥* @param cipherData* 密文数据* @return 明文* @throws Exception* 解密过程中的异常信息*/public byte[] decrypt(RSAPrivateKey privateKey, byte[] cipherData)throws Exception {if (privateKey == null) {throw new Exception("解密私钥为空, 请设置");}Cipher cipher = null;try {// , new BouncyCastleProvider()cipher = Cipher.getInstance("RSA");cipher.init(Cipher.DECRYPT_MODE, privateKey);byte[] output = cipher.doFinal(cipherData);return output;} catch (NoSuchAlgorithmException e) {throw new Exception("无此解密算法");} catch (NoSuchPaddingException e) {e.printStackTrace();return null;} catch (InvalidKeyException e) {throw new Exception("解密私钥非法,请检查");} catch (IllegalBlockSizeException e) {throw new Exception("密文长度非法");} catch (BadPaddingException e) {throw new Exception("密文数据已损坏");}}/*** 字节数据转十六进制字符串* * @param data* 输入数据* @return 十六进制内容*/public static String byteArrayToString(byte[] data) {StringBuilder stringBuilder = new StringBuilder();for (int i = 0; i < data.length; i++) {// 取出字节的高四位 作为索引得到相应的十六进制标识符 注意无符号右移stringBuilder.append(HEX_CHAR[(data[i] & 0xf0) >>> 4]);// 取出字节的低四位 作为索引得到相应的十六进制标识符stringBuilder.append(HEX_CHAR[(data[i] & 0x0f)]);if (i < data.length - 1) {stringBuilder.append(' ');}}return stringBuilder.toString();}// btye转换hex函数public static String ByteToHex(byte[] byteArray) {StringBuffer StrBuff = new StringBuffer();for (int i = 0; i < byteArray.length; i++) {if (Integer.toHexString(0xFF & byteArray[i]).length() == 1) {StrBuff.append("0").append(Integer.toHexString(0xFF & byteArray[i]));} else {StrBuff.append(Integer.toHexString(0xFF & byteArray[i]));}}return StrBuff.toString();}/*** 以字节为单位读取文件，常用于读二进制文件，如图片、声音、影像等文件。*/public static byte[] readFileByBytes(String fileName) {File file = new File(fileName);InputStream in = null;byte[] txt = new byte[(int) file.length()];try {// 一次读一个字节in = new FileInputStream(file);int tempbyte;int i = 0;while ((tempbyte = in.read()) != -1) {txt[i] = (byte) tempbyte;i++;}in.close();return txt;} catch (IOException e) {e.printStackTrace();return txt;}}public static void main(String[] args) {RsaEncrypt RsaEncrypt = new RsaEncrypt();// RsaEncrypt.genKeyPair();// 加载公钥try {RsaEncrypt.loadPublicKey(RsaEncrypt.DEFAULT_PUBLIC_KEY);System.out.println("加载公钥成功");} catch (Exception e) {System.err.println(e.getMessage());System.err.println("加载公钥失败");}// 加载私钥try {RsaEncrypt.loadPrivateKey(RsaEncrypt.DEFAULT_PRIVATE_KEY);System.out.println("加载私钥成功");} catch (Exception e) {System.err.println(e.getMessage());System.err.println("加载私钥失败");}// 测试字符串String encryptStr = "12321dsfasf1321312fsfdsafsdafasfsadf";try {System.out.println(new Date());// 加密byte[] cipher = RsaEncrypt.encrypt(RsaEncrypt.getPublicKey(),encryptStr.getBytes());// 解密byte[] plainText = RsaEncrypt.decrypt(RsaEncrypt.getPrivateKey(),cipher);System.out.println(new Date());// System.out.println("密文长度:"+ cipher.length);// System.out.println(RsaEncrypt.byteArrayToString(cipher));// System.out.println("明文长度:"+ plainText.length);// System.out.println(RsaEncrypt.byteArrayToString(plainText));System.out.println(new String(plainText));// 签名验证byte[] signbyte = RsaEncrypt.rsaSign("helloadsfdsfaasdfasffffffffffffdsafdasfasdfsafzxvxzvasfs",RsaEncrypt.getPrivateKey());System.out.println("签名-----：" + ByteToHex(signbyte));Boolean isok = RsaEncrypt.doCheck("helloadsfdsfaasdfasffffffffffffdsafdasfasdfsafzxvxzvasfs", signbyte,RsaEncrypt.getPublicKey());System.out.println("验证：" + isok);// 读取验证文件byte[] read = readFileByBytes("C:/openssl-1.0.2c-static-x86/bin/rsasign.bin");System.out.println("读取签名文件：" + ByteToHex(read));Boolean isfok = RsaEncrypt.doCheck("helloadsfdsfaasdfasffffffffffffdsafdasfasdfsafzxvxzvasfs", read,RsaEncrypt.getPublicKey());System.out.println("文件验证：" + isfok);} catch (Exception e) {System.err.println(e.getMessage());}}}
