数字签名算法的具体使用测试

ゝ一纸荒年。 2022-06-13 07:29 215阅读 0赞

代码：

RSAUtils.java

package com.util;
 
 import java.io.ByteArrayOutputStream; 
 import java.security.Key; 
 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.RSAPrivateKey; 
 import java.security.interfaces.RSAPublicKey; 
 import java.security.spec.PKCS8EncodedKeySpec; 
 import java.security.spec.X509EncodedKeySpec;
 import java.util.HashMap; 
 import java.util.Map; 
 
 import javax.crypto.Cipher; 
 
 public class RSAUtils { 
 
 /*
 * 加密算法RSA 
 */ 
 public static final String KEY_ALGORITHM = "RSA"; 
 
 /* 
 * 签名算法 
 */ 
 public static final String SIGNATURE_ALGORITHM = "MD5withRSA"; 
 
 /* 
 * 获取公钥的key 
 */ 
 private static final String PUBLIC_KEY = "RSAPublicKey"; 
 
 /* 
 * 获取私钥的key 
 */ 
 private static final String PRIVATE_KEY = "RSAPrivateKey"; 
 
 /* 
 * 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; 
 
 /* 
 * 
 * 生成密钥对(公钥和私钥) 
 * 
 */ 
 public static Map<String, Object> genKeyPair() throws Exception { 
 KeyPairGenerator keyPairGen = KeyPairGenerator.getInstance(KEY_ALGORITHM); 
 keyPairGen.initialize(1024); 
 KeyPair keyPair = keyPairGen.generateKeyPair(); 
 RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic(); 
 RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate(); 
 Map<String, Object> keyMap = new HashMap<String, Object>(2); 
 keyMap.put(PUBLIC_KEY, publicKey); 
 keyMap.put(PRIVATE_KEY, privateKey); 
 return keyMap; 
 } 
 
 /* 
 * 
 * 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) 
 */ 
 public static String sign(byte[] data, String privateKey) throws Exception { 
 byte[] keyBytes = Base64.decode(privateKey); 
 PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes); 
 KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM); 
 PrivateKey privateK = keyFactory.generatePrivate(pkcs8KeySpec); 
 Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM); 
 signature.initSign(privateK); 
 signature.update(data); 
 return Base64.encode(signature.sign()); 
 } 
 
 /*
 * 
 * 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 
 * 
 */ 
 public static boolean verify(byte[] data, String publicKey, String sign) 
 throws Exception { 
 byte[] keyBytes = Base64.decode(publicKey); 
 X509EncodedKeySpec keySpec = new X509EncodedKeySpec(keyBytes); 
 KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM); 
 PublicKey publicK = keyFactory.generatePublic(keySpec); 
 Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM); 
 signature.initVerify(publicK); 
 signature.update(data); 
 return signature.verify(Base64.decode(sign)); 
 } 
 
 /*
 * 
 * 私钥解密 
 * 
 * 
 * @param encryptedData 已加密数据 
 * @param privateKey 私钥(BASE64编码) 
 */ 
 public static byte[] decryptByPrivateKey(byte[] encryptedData, String privateKey) 
 throws Exception { 
 byte[] keyBytes = Base64.decode(privateKey); 
 PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes); 
 KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM); 
 Key privateK = keyFactory.generatePrivate(pkcs8KeySpec); 
 Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm()); 
 cipher.init(Cipher.DECRYPT_MODE, privateK); 
 int inputLen = encryptedData.length; 
 ByteArrayOutputStream out = new ByteArrayOutputStream(); 
 int offSet = 0; 
 byte[] cache; 
 int i = 0; 
 // 对数据分段解密 
 while (inputLen - offSet > 0) { 
 if (inputLen - offSet > MAX_DECRYPT_BLOCK) { 
 cache = cipher.doFinal(encryptedData, offSet, MAX_DECRYPT_BLOCK); 
 } else { 
 cache = cipher.doFinal(encryptedData, offSet, inputLen - offSet); 
 } 
 out.write(cache, 0, cache.length); 
 i++; 
 offSet = i * MAX_DECRYPT_BLOCK; 
 } 
 byte[] decryptedData = out.toByteArray(); 
 out.close(); 
 return decryptedData; 
 } 
 
 /*
 * 
 * 公钥解密 
 * 
 * 
 * @param encryptedData 已加密数据 
 * @param publicKey 公钥(BASE64编码) 
 */ 
 public static byte[] decryptByPublicKey(byte[] encryptedData, String publicKey) 
 throws Exception { 
 byte[] keyBytes = Base64.decode(publicKey); 
 X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes); 
 KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM); 
 Key publicK = keyFactory.generatePublic(x509KeySpec); 
 Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm()); 
 cipher.init(Cipher.DECRYPT_MODE, publicK); 
 int inputLen = encryptedData.length; 
 ByteArrayOutputStream out = new ByteArrayOutputStream(); 
 int offSet = 0; 
 byte[] cache; 
 int i = 0; 
 // 对数据分段解密 
 while (inputLen - offSet > 0) { 
 if (inputLen - offSet > MAX_DECRYPT_BLOCK) { 
 cache = cipher.doFinal(encryptedData, offSet, MAX_DECRYPT_BLOCK); 
 } else { 
 cache = cipher.doFinal(encryptedData, offSet, inputLen - offSet); 
 } 
 out.write(cache, 0, cache.length); 
 i++; 
 offSet = i * MAX_DECRYPT_BLOCK; 
 } 
 byte[] decryptedData = out.toByteArray(); 
 out.close(); 
 return decryptedData; 
 } 
 
 /*
 * 
 * 公钥加密 
 * 
 * 
 * @param data 源数据 
 * @param publicKey 公钥(BASE64编码) 
 */ 
 public static byte[] encryptByPublicKey(byte[] data, String publicKey) 
 throws Exception { 
 byte[] keyBytes = Base64.decode(publicKey); 
 X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes); 
 KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM); 
 Key publicK = keyFactory.generatePublic(x509KeySpec); 
 // 对数据加密 
 Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm()); 
 cipher.init(Cipher.ENCRYPT_MODE, publicK); 
 int inputLen = data.length; 
 ByteArrayOutputStream out = new ByteArrayOutputStream(); 
 int offSet = 0; 
 byte[] cache; 
 int i = 0; 
 // 对数据分段加密 
 while (inputLen - offSet > 0) { 
 if (inputLen - offSet > MAX_ENCRYPT_BLOCK) { 
 cache = cipher.doFinal(data, offSet, MAX_ENCRYPT_BLOCK); 
 } else { 
 cache = cipher.doFinal(data, offSet, inputLen - offSet); 
 } 
 out.write(cache, 0, cache.length); 
 i++; 
 offSet = i * MAX_ENCRYPT_BLOCK; 
 } 
 byte[] encryptedData = out.toByteArray(); 
 out.close(); 
 return encryptedData; 
 } 
 
 /*
 * 
 * 私钥加密 
 * 
 * 
 * @param data 源数据 
 * @param privateKey 私钥(BASE64编码) 
 */ 
 public static byte[] encryptByPrivateKey(byte[] data, String privateKey) 
 throws Exception { 
 byte[] keyBytes = Base64.decode(privateKey); 
 PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes); 
 KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM); 
 Key privateK = keyFactory.generatePrivate(pkcs8KeySpec); 
 Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm()); 
 cipher.init(Cipher.ENCRYPT_MODE, privateK); 
 int inputLen = data.length; 
 ByteArrayOutputStream out = new ByteArrayOutputStream(); 
 int offSet = 0; 
 byte[] cache; 
 int i = 0; 
 // 对数据分段加密 
 while (inputLen - offSet > 0) { 
 if (inputLen - offSet > MAX_ENCRYPT_BLOCK) { 
 cache = cipher.doFinal(data, offSet, MAX_ENCRYPT_BLOCK); 
 } else { 
 cache = cipher.doFinal(data, offSet, inputLen - offSet); 
 } 
 out.write(cache, 0, cache.length); 
 i++; 
 offSet = i * MAX_ENCRYPT_BLOCK; 
 } 
 byte[] encryptedData = out.toByteArray(); 
 out.close(); 
 return encryptedData; 
 } 
 
 /*
 * 
 * 获取私钥 
 * 
 * 
 * @param keyMap 密钥对 
 */ 
 public static String getPrivateKey(Map<String, Object> keyMap) 
 throws Exception { 
 Key key = (Key) keyMap.get(PRIVATE_KEY); 
 return Base64.encode(key.getEncoded()); 
 } 
 
 /*
 * 
 * 获取公钥 
 * 
 * 
 * @param keyMap 密钥对 
 */ 
 public static String getPublicKey(Map<String, Object> keyMap) 
 throws Exception { 
 Key key = (Key) keyMap.get(PUBLIC_KEY); 
 return Base64.encode(key.getEncoded()); 
 } 
 }

Base64.java(Base64编码)

package com.util;
 
 public class Base64 
 { 
 private static char[] Base64Code = { 
 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 
 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 
 'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd', 
 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 
 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 
 'y', 'z', '0', '1', '2', '3', '4', '5', '6', '7', 
 '8', '9', '+', '/' }; 
 
 private static byte[] Base64Decode = { 
 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 
 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 
 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 
 -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 
 -1, -1, -1, 62, -1, 63, -1, 63, 52, 53, 
 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, 
 -1, 0, -1, -1, -1, 0, 1, 2, 3, 4, 
 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 
 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 
 25, -1, -1, -1, -1, -1, -1, 26, 27, 28, 
 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 
 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 
 49, 50, 51, -1, -1, -1, -1, -1 }; 
 
 public static String encode(byte[] b) 
 { 
 int code = 0; 
 if (b == null) 
 return null; 
 StringBuffer sb = new StringBuffer((b.length - 1) / 3 << 6); 
 for (int i = 0; i < b.length; i++) 
 { 
 code |= b[i] << 16 - i % 3 * 8 & 255 << 16 - i % 3 * 8; 
 if ((i % 3 != 2) && (i != b.length - 1)) 
 continue; 
 sb.append(Base64Code[((code & 0xFC0000) >>> 18)]); 
 sb.append(Base64Code[((code & 0x3F000) >>> 12)]); 
 sb.append(Base64Code[((code & 0xFC0) >>> 6)]); 
 sb.append(Base64Code[(code & 0x3F)]); 
 code = 0; 
 } 
 
 if (b.length % 3 > 0) 
 sb.setCharAt(sb.length() - 1, '='); 
 if (b.length % 3 == 1) 
 sb.setCharAt(sb.length() - 2, '='); 
 return sb.toString(); 
 } 
 
 public static byte[] decode(String code) 
 { 
 if (code == null) 
 return null; 
 int len = code.length(); 
 if (len % 4 != 0) 
 throw new IllegalArgumentException("Base64 string length must be 4*n"); 
 if (code.length() == 0) 
 return new byte[0]; 
 int pad = 0; 
 if (code.charAt(len - 1) == '=') 
 pad++; 
 if (code.charAt(len - 2) == '=') 
 pad++; 
 int retLen = len / 4 * 3 - pad; 
 byte[] ret = new byte[retLen]; 
 for (int i = 0; i < len; i += 4) 
 { 
 int j = i / 4 * 3; 
 char ch1 = code.charAt(i); 
 char ch2 = code.charAt(i + 1); 
 char ch3 = code.charAt(i + 2); 
 char ch4 = code.charAt(i + 3); 
 int tmp = Base64Decode[ch1] << 18 | Base64Decode[ch2] << 12 | Base64Decode[ch3] << 6 | Base64Decode[ch4]; 
 ret[j] = (byte)((tmp & 0xFF0000) >> 16); 
 if (i < len - 4) 
 { 
 ret[(j + 1)] = (byte)((tmp & 0xFF00) >> 8); 
 ret[(j + 2)] = (byte)(tmp & 0xFF); 
 } 
 else { 
 if (j + 1 < retLen) 
 ret[(j + 1)] = (byte)((tmp & 0xFF00) >> 8); 
 if (j + 2 < retLen) 
 ret[(j + 2)] = (byte)(tmp & 0xFF); 
 } 
 } 
 return ret; 
 } 
 }

RSATester.java (数字签名测试类)

package com.util;
 
 import java.util.Map; 
 
 public class RSATester { 
 static String publicKey; 
 static String privateKey; 
 
 static { 
 try { 
 Map<String, Object> keyMap = RSAUtils.genKeyPair(); 
 publicKey = RSAUtils.getPublicKey(keyMap); 
 privateKey = RSAUtils.getPrivateKey(keyMap); 
 System.err.println("公钥: \n\r" + publicKey); 
 System.err.println("私钥： \n\r" + privateKey); 
 } catch (Exception e) { 
 e.printStackTrace(); 
 } 
 } 
 
 public static void main(String[] args) throws Exception { 
 //test(); 
 testSign(); 
 } 
 
 /*
 * 公钥加密，私钥解密的签名机制
 */
 static void test() throws Exception { 
 System.err.println("公钥加密——私钥解密"); 
 String source = "海哥"; 
 System.out.println("\r加密前文字：\r\n" + source); 
 byte[] data = source.getBytes(); 
 //公钥加密 
 byte[] encodedData = RSAUtils.encryptByPublicKey(data, publicKey); 
 System.out.println("加密后文字：\r\n" + new String(encodedData)); 
 //私钥解密 
 byte[] decodedData = RSAUtils.decryptByPrivateKey(encodedData, privateKey); 
 String target = new String(decodedData); 
 System.out.println("解密后文字: \r\n" + target); 
 } 
 /*
 * 私钥加密，公钥解密的签名机制(个人比较喜欢用这种)
 */
 static void testSign() throws Exception { 
 System.err.println("私钥加密——公钥解密"); 
 //String source = "my Test -----200---测试RSA数字签名的原始数据"; 
 String source = "海马汽车2017年5月20日"; 
 System.out.println("原文字：\r\n" + source); 
 byte[] data = source.getBytes("UTF-8"); 
 //私钥加密 
 byte[] encodedData = RSAUtils.encryptByPrivateKey(data, privateKey); 
 System.out.println("加密后：\r\n" + new String(encodedData)); 
 //公钥解密 
 byte[] decodedData = RSAUtils.decryptByPublicKey(encodedData, publicKey); 
 String target = new String(decodedData); 
 System.out.println("解密后: \r\n" + target); 
 
 System.err.println("私钥签名——公钥验证签名"); 
 String sign = RSAUtils.sign(encodedData, privateKey); 
 System.err.println("签名:\r" + sign); 
 boolean status = RSAUtils.verify(encodedData, publicKey, sign); 
 System.err.println("验证结果:\r" + status); 
 } 
 }

测试结果：

![Center][]

[Center]: /images/20220613/647c9320256c45ada1028e9b362875e8.png