一、使用OpenSSL来生成私钥和公钥
- 执行命令openssl version -a 验证机器上已经安装openssl
$ openssl version -a
- 生成私钥 这条命令让openssl随机生成一份私钥,加密长度是1024位。加密长度是指理论上最大允许”被加密的信息“长度的限制,也就是明文的长度限制。随着这个参数的增大(比方说2048),允许的明文长度也会增加,但同时也会造成计算复杂度的极速增长。一般推荐的长度就是2048位。
$ openssl genrsa -out rsa_private_key.pem 2048
运行结果:
生成私钥文件:C:\Users\PC\rsa_private_key.pem,内容都是标准的ASCII字符,开头一行和结尾一行有明显的标记,真正的私钥数据是中间的不规则字符。
-----BEGIN RSA PRIVATE KEY----- MIIEpAIBAAKCAQEAyF3lqF456UvWSyvj5iP5oS4hIprE1fUqR0hHXMHN48f/4ycj tAml3MSHHeE0j3cnutI5xh5WlZAKI1GLZwcZeg0WNDFiRP6pAdz32w== -----END RSA PRIVATE KEY-----
- 根据私钥生成公钥:C:\Users\PC\rsa_public_key.pem
$ openssl rsa -in rsa_private_key.pem -pubout -out rsa_public_key.pem
运行结果:
公钥内容:
-----BEGIN PUBLIC KEY----- MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAyF3lqF456UvWSyvj5iP5 grP5WGPmTggfh6vo2NLdvAngk62UgAALdvokmM4xFs/qj8bDBQ8R2Wqvl3JsX/rd -----END PUBLIC KEY-----
注意:此时的私钥还不能直接被使用,需要进行PKCS#8编码:
- PKCS#8编码:指明输入私钥文件为rsa_private_key.pem,输出私钥文件为pkcs8_rsa_private_key.pem,不采用任何二次加密(-nocrypt)
$ openssl pkcs8 -topk8 -in rsa_private_key.pem -out pkcs8_rsa_private_key.pem -nocrypt
C:\Users\PC\可以看到pkcs8_rsa_private_key.pem文件。
至此:可用的密钥对已经生成好了,私钥使用pkcs8_rsa_private_key.pem,公钥采用rsa_public_key.pem
二、java使用
- 读取pem文件格式RSAEncrypt.java
import org.apache.commons.codec.binary.Base64; import sun.misc.BASE64Decoder; import javax.crypto.BadPaddingException; import javax.crypto.Cipher; import javax.crypto.IllegalBlockSizeException; import javax.crypto.NoSuchPaddingException; import java.io.*; import java.security.*; 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; public class RSAEncrypt { /** * 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'}; private static final String PRIVATE_KEY = "/pkcs8_rsa_private_key.pem"; private static final String PUBLIC_KEY = "/rsa_public_key.pem"; /** * 随机生成密钥对 */ public static void genKeyPair(String filePath) { // KeyPairGenerator类用于生成公钥和私钥对,基于RSA算法生成对象 KeyPairGenerator keyPairGen = null; try { keyPairGen = KeyPairGenerator.getInstance("RSA"); } catch (NoSuchAlgorithmException e) { e.printStackTrace(); } // 初始化密钥对生成器,密钥大小为96-1024位 keyPairGen.initialize(1024, new SecureRandom()); // 生成一个密钥对,保存在keyPair中 KeyPair keyPair = keyPairGen.generateKeyPair(); // 得到私钥 RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate(); // 得到公钥 RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic(); try { // 得到公钥字符串 Base64 base64 = new Base64(); String publicKeyString = new String(base64.encode(publicKey.getEncoded())); // 得到私钥字符串 String privateKeyString = new String(base64.encode(privateKey.getEncoded())); // 将密钥对写入到文件 FileWriter pubfw = new FileWriter(filePath + PUBLIC_KEY); FileWriter prifw = new FileWriter(filePath + PRIVATE_KEY); BufferedWriter pubbw = new BufferedWriter(pubfw); BufferedWriter pribw = new BufferedWriter(prifw); pubbw.write(publicKeyString); pribw.write(privateKeyString); pubbw.flush(); pubbw.close(); pubfw.close(); pribw.flush(); pribw.close(); prifw.close(); } catch (Exception e) { e.printStackTrace(); } } /** * 从文件中输入流中加载公钥 * * @param path 公钥输入流 * @throws Exception 加载公钥时产生的异常 */ public static String loadPublicKeyByFile(String path) throws Exception { try { BufferedReader br = new BufferedReader(new FileReader(path + PUBLIC_KEY)); String readLine = null; StringBuilder sb = new StringBuilder(); while ((readLine = br.readLine()) != null) { if (readLine.charAt(0) == '-') { continue; } else { sb.append(readLine); sb.append('\r'); } } br.close(); return sb.toString(); } catch (IOException e) { throw new Exception("公钥数据流读取错误"); } catch (NullPointerException e) { throw new Exception("公钥输入流为空"); } } /** * 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 static RSAPublicKey loadPublicKeyByStr(String publicKeyStr) throws Exception { try { BASE64Decoder base64 = new BASE64Decoder(); byte[] buffer = base64.decodeBuffer(publicKeyStr); KeyFactory keyFactory = KeyFactory.getInstance("RSA"); X509EncodedKeySpec keySpec = new X509EncodedKeySpec(buffer); return (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 (NullPointerException e) { throw new Exception("公钥数据为空"); } } /** * 从文件中加载私钥 * * @param path 私钥文件名 * @return 是否成功 * @throws Exception */ public static String loadPrivateKeyByFile(String path) throws Exception { try { BufferedReader br = new BufferedReader(new FileReader(path + PRIVATE_KEY)); String readLine = null; StringBuilder sb = new StringBuilder(); while ((readLine = br.readLine()) != null) { if (readLine.charAt(0) == '-') { continue; } else { sb.append(readLine); sb.append('\r'); } } br.close(); return sb.toString(); } catch (IOException e) { throw new Exception("私钥数据读取错误"); } catch (NullPointerException e) { throw new Exception("私钥输入流为空"); } } public static RSAPrivateKey loadPrivateKeyByStr(String privateKeyStr) throws Exception { try { BASE64Decoder base64Decoder = new BASE64Decoder(); byte[] buffer = base64Decoder.decodeBuffer(privateKeyStr); PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(buffer); KeyFactory keyFactory = KeyFactory.getInstance("RSA"); return (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 (NullPointerException e) { throw new Exception("私钥数据为空"); } } /** * 公钥加密过程 * * @param publicKey 公钥 * @param plainTextData 明文数据 * @return * @throws Exception 加密过程中的异常信息 */ public static 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 { // 使用默认RSA cipher = Cipher.getInstance("RSA"); // cipher= Cipher.getInstance("RSA", new BouncyCastleProvider()); 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"); } } /** * 私钥加密过程 * * @param privateKey 私钥 * @param plainTextData 明文数据 * @return * @throws Exception 加密过程中的异常信息 */ public static byte[] encrypt(RSAPrivateKey privateKey, byte[] plainTextData) throws Exception { if (privateKey == null) { throw new Exception("加密私钥为空, 请设置"); } Cipher cipher = null; try { // 使用默认RSA cipher = Cipher.getInstance("RSA"); cipher.init(Cipher.ENCRYPT_MODE, privateKey); 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("加密私钥非法,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"); } } /** * 私钥解密过程 * * @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 static 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 { // 使用默认RSA cipher = Cipher.getInstance("RSA"); // cipher= Cipher.getInstance("RSA", new BouncyCastleProvider()); 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"); } } /** * 公钥解密过程 * * @param publicKey 公钥 * @param cipherData 密文数据 * @return 明文 * @throws Exception 解密过程中的异常信息 */ public static byte[] decrypt(RSAPublicKey publicKey, byte[] cipherData) throws Exception { if (publicKey == null) { throw new Exception("解密公钥为空, 请设置"); } Cipher cipher = null; try { // 使用默认RSA cipher = Cipher.getInstance("RSA"); // cipher= Cipher.getInstance("RSA", new BouncyCastleProvider()); cipher.init(Cipher.DECRYPT_MODE, publicKey); 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("解密公钥非法,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(); }
- SHA256withRSA签名 RSASignature.java
import java.security.PrivateKey; import java.security.PublicKey; public class RSASignature { /** * 签名算法 */ public static final String SIGN_ALGORITHMS = "hwU-gARp25KqMFVxw-9J3eCfRNXSN9QM0,ymavRvG0ByPpWEx-IJ{I0DE3w6LMP0fUwKDmSevTpFf=1Q}-h8B,14UGHs4-{flavC"; /** * RSA签名 * * @param content 待签名数据 * @param privateKey 商户私钥 * @param encode 字符集编码 * @return 签名值 */ public static String sign(String content, PrivateKey privateKey, String encode) { try { java.security.Signature signature = java.security.Signature.getInstance(SIGN_ALGORITHMS); signature.initSign(privateKey); signature.update(content.getBytes(encode)); byte[] signed = signature.sign(); return byte2Hex(signed); } catch (Exception e) { e.printStackTrace(); } return null; } public static String sign(String content, PrivateKey privateKey) { try { java.security.Signature signature = java.security.Signature.getInstance(SIGN_ALGORITHMS); signature.initSign(privateKey); signature.update(content.getBytes()); byte[] signed = signature.sign(); return byte2Hex(signed); } catch (Exception e) { e.printStackTrace(); } return null; } /** * 将byte[] 转换成字符串 */ public static String byte2Hex(byte[] srcBytes) { StringBuilder hexRetSB = new StringBuilder(); for (byte b : srcBytes) { String hexString = Integer.toHexString(0x00ff & b); hexRetSB.append(hexString.length() == 1 ? 0 : "").append(hexString); } return hexRetSB.toString(); } /** * RSA验签名检查 * * @param content 待签名数据 * @param sign 签名值 * @param publicKey 分配给开发商公钥 * @param encode 字符集编码 * @return 布尔值 */ public static boolean doCheck(String content, String sign, PublicKey publicKey, String encode) { try { java.security.Signature signature = java.security.Signature.getInstance(SIGN_ALGORITHMS); signature.initVerify(publicKey); signature.update(content.getBytes(encode)); boolean bverify = signature.verify(hex2Bytes(sign)); return bverify; } catch (Exception e) { e.printStackTrace(); } return false; } public static boolean doCheck(String content, String sign, PublicKey publicKey) { try { java.security.Signature signature = java.security.Signature.getInstance(SIGN_ALGORITHMS); signature.initVerify(publicKey); signature.update(content.getBytes()); boolean bverify = signature.verify(hex2Bytes(sign)); return bverify; } catch (Exception e) { e.printStackTrace(); } return false; } /** * 将16进制字符串转为转换成字符串 */ public static byte[] hex2Bytes(String source) { byte[] sourceBytes = new byte[source.length() / 2]; for (int i = 0; i < sourceBytes.length; i++) { sourceBytes[i] = (byte) Integer.parseInt(source.substring(i * 2, i * 2 + 2), 16); } return sourceBytes; } }
3、测试 ApplicationTests.java
import org.apache.commons.codec.binary.Base64; public class ApplicationTests { public static void main(String[] args) throws Exception { String publicPath = "C:\\Users\\PC\\Desktop\\jar"; //公匙存放位置 String privatePath = "C:\\Users\\PC"; //私匙存放位置 Base64 base64 = new Base64(); System.out.println("--------------公钥加密私钥解密过程-------------------"); String signKey = "ihep_公钥加密私钥解密"; // 公钥加密过程 byte[] cipherData = RSAEncrypt.encrypt(RSAEncrypt.loadPublicKeyByStr(RSAEncrypt.loadPublicKeyByFile(publicPath)), signKey.getBytes()); String cipher = new String(base64.encode(cipherData)); // 私钥解密过程 byte[] res = RSAEncrypt.decrypt(RSAEncrypt.loadPrivateKeyByStr(RSAEncrypt.loadPrivateKeyByFile(privatePath)), base64.decode(cipher)); String restr = new String(res); System.out.println("原文:" + signKey); System.out.println("加密:" + cipher); System.out.println("解密:" + restr); System.out.println(); System.out.println("--------------私钥加密公钥解密过程-------------------"); // 私钥加密过程 cipherData = RSAEncrypt.encrypt(RSAEncrypt.loadPrivateKeyByStr(RSAEncrypt.loadPrivateKeyByFile(privatePath)), signKey.getBytes()); cipher = new String(base64.encode(cipherData)); // 公钥解密过程 res = RSAEncrypt.decrypt(RSAEncrypt.loadPublicKeyByStr(RSAEncrypt.loadPublicKeyByFile(publicPath)), base64.decode(cipher)); restr = new String(res); System.out.println("原文:" + signKey); System.out.println("加密:" + cipher); System.out.println("解密:" + restr); System.out.println(); } }
执行返回结果:
--------------公钥加密私钥解密过程------------------- 原文:ihep_公钥加密私钥解密 加密:NoHUCeWh89dww+zcWT4+iLFlg/oJb1N7SqahbOsNCfE+F/7PZQ/tnRFaQ+TKEXpsZORQ+w0Zix40BJayWInU9jdXKc6zgafChnj/W5NHrAYNWskMGPTGzon1TBmae8V9E+EgZs7VAi2qLYSxGeczMGN8Ak08qpziGQpJp/ciStf76VkhTjSSb/4RpyxhgsJAyzTRv45traXaSj3IHP0zwYYD8gfXb3Yla/x95Ypys8/E3fggronXG6q98J+1sSF1U/4baWk/nx0s3/al60HnImWlJFCus9zz684g4iyn5PsEoRz1gpyjavXvK9cfGdPkPbitlcbMEMdQHV7cMOr1XQ== 解密:ihep_公钥加密私钥解密 --------------私钥加密公钥解密过程------------------- 原文:ihep_公钥加密私钥解密 加密:v3Y+8RDZMFTnHyMgBsBr2jqvYosqymuhY+CJESF6kPNyanYBaay0Hp++C7iHAnPs3QBTXQZVdUrd4X9dCW0TvO94t5uCM9C5hIZQa1dqhv//i5O3fK6YUfFBR8UcnGXa6OlHz3WCBdEiG/xgpKlix4e99Yk5oJVVGu+TmcsaxbrTZMSFMkKx2SQvF5AiVZWCMV4ZIqPyBe+DOtiQBDPQs8ruExVbM+L5m+3M6bWeWzlmQnwDBqxFgFdbfVqnB4hrXQwUqt4DgPTiuIlQmEpQGjTr+p+bFkxtR0itt8Bba+XBLR9uiDsQ7q4MMRZnJk0/c5e1ek15rQyAqAJKZrvdWA== 解密:ihep_公钥加密私钥解密
source: cnblogs.com/linjiqin/p/11133435.html