rsa加密前后端交互.前端加密后端解密

package com.rsa.utils.rsa; import com.rsa.system.controller.RsaConfig; import org.springframework.beans.factory.annotation.Autowired; import javax.crypto.Cipher; import java.io.ByteArrayOutputStream; import java.math.BigInteger; import java.security.KeyFactory; import java.security.KeyPair; import java.security.KeyPairGenerator; import java.security.NoSuchAlgorithmException; import java.security.interfaces.RSAPrivateKey; import java.security.interfaces.RSAPublicKey; import java.security.spec.RSAPrivateKeySpec; import java.security.spec.RSAPublicKeySpec; public class RSA_Util { private static final int MAX_ENCRYPT_BLOCK = 117; // RSA最大加密明文大小 private static final int MAX_DECRYPT_BLOCK = 128; // RSA最大解密密文大小 @Autowired RsaConfig bootdoConfig; public static void main(String[] args) throws Exception { KeyPair keyPair = genRSAKeyPair(); //生成公钥和私钥 RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic(); RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate(); //模hex String modulus = publicKey.getModulus().toString(16); System.out.println("模："+modulus); //公钥指数hex String public_exponent = publicKey.getPublicExponent().toString(16); System.out.println("公钥："+public_exponent); //私钥指数hex String private_exponent = privateKey.getPrivateExponent().toString(16); System.out.println("私钥："+private_exponent); //明文 String plaintStr = "今晚月色真美，风也温柔！@#￥#%……￥#%43"; System.out.println("原的文本："+plaintStr); //使用模和指数生成公钥和私钥 RSAPublicKey pubKey = getPublicKey(modulus, public_exponent); RSAPrivateKey priKey = getPrivateKey(modulus, private_exponent); //公钥加密后的密文 byte[] encryptStr = encryptByPublicKey(plaintStr.getBytes("utf-8"), pubKey); String pubStr= HexUtil.byte2hex(encryptStr); System.out.println("加密后的文本："+pubStr); //私钥解密后的明文 byte[] decryptStr = decryptByPrivateKey(HexUtil.hex2byte(pubStr), priKey); System.out.println("解密后的文本："+new String(decryptStr)); } /** * 生成公钥和私钥 * * @throws NoSuchAlgorithmException */ public static KeyPair genRSAKeyPair() throws NoSuchAlgorithmException { KeyPairGenerator keyPairGen = KeyPairGenerator.getInstance("RSA"); keyPairGen.initialize(1024); return keyPairGen.generateKeyPair(); } /** * 使用模和指数生成RSA公钥 * 注意：【此代码用了默认补位方式，为RSA/None/PKCS1Padding，不同JDK默认的补位方式可能不同，如Android默认是RSA * /None/NoPadding】 * * @param modulus 模 * @param exponent 指数 * @return */ public static RSAPublicKey getPublicKey(String modulus, String exponent) { try { BigInteger b1 = new BigInteger(modulus, 16); BigInteger b2 = new BigInteger(exponent, 16); KeyFactory keyFactory = KeyFactory.getInstance("RSA"); RSAPublicKeySpec keySpec = new RSAPublicKeySpec(b1, b2); return (RSAPublicKey) keyFactory.generatePublic(keySpec); } catch (Exception e) { e.printStackTrace(); return null; } } /** * 使用模和指数生成RSA私钥 * 注意：【此代码用了默认补位方式，为RSA/None/PKCS1Padding，不同JDK默认的补位方式可能不同，如Android默认是RSA * /None/NoPadding】 * * @param modulus 模 * @param exponent 指数 * @return */ public static RSAPrivateKey getPrivateKey(String modulus, String exponent) { try { BigInteger b1 = new BigInteger(modulus, 16); BigInteger b2 = new BigInteger(exponent, 16); KeyFactory keyFactory = KeyFactory.getInstance("RSA"); RSAPrivateKeySpec keySpec = new RSAPrivateKeySpec(b1, b2); return (RSAPrivateKey) keyFactory.generatePrivate(keySpec); } catch (Exception e) { e.printStackTrace(); return null; } } /** * 公钥加密 */ public static byte[] encryptByPublicKey(byte[] data, RSAPublicKey publicKey) throws Exception { Cipher cipher = Cipher.getInstance("RSA"); cipher.init(Cipher.ENCRYPT_MODE, publicKey); int inputLen = data.length; try (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; } return out.toByteArray(); } } /** * 私钥解密 */ public static byte[] decryptByPrivateKey(byte[] encryptedData, RSAPrivateKey privateKey) throws Exception { Cipher cipher = Cipher.getInstance("RSA"); cipher.init(Cipher.DECRYPT_MODE, privateKey); int inputLen = encryptedData.length; try (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; } return out.toByteArray(); } } /** * ASCII码转BCD码 */ public static byte[] ASCII_To_BCD(byte[] ascii, int asc_len) { byte[] bcd = new byte[asc_len / 2]; int j = 0; for (int i = 0; i < (asc_len + 1) / 2; i++) { bcd[i] = asc_to_bcd(ascii[j++]); bcd[i] = (byte) (((j >= asc_len) ? 0x00 : asc_to_bcd(ascii[j++])) + (bcd[i] << 4)); } return bcd; } public static byte asc_to_bcd(byte asc) { byte bcd; if ((asc >= '0') && (asc <= '9')) bcd = (byte) (asc - '0'); else if ((asc >= 'A') && (asc <= 'F')) bcd = (byte) (asc - 'A' + 10); else if ((asc >= 'a') && (asc <= 'f')) bcd = (byte) (asc - 'a' + 10); else bcd = (byte) (asc - 48); return bcd; } /** * BCD转字符串 */ public static String bcd2Str(byte[] bytes) { char temp[] = new char[bytes.length * 2], val; for (int i = 0; i < bytes.length; i++) { val = (char) (((bytes[i] & 0xf0) >> 4) & 0x0f); temp[i * 2] = (char) (val > 9 ? val + 'A' - 10 : val + '0'); val = (char) (bytes[i] & 0x0f); temp[i * 2 + 1] = (char) (val > 9 ? val + 'A' - 10 : val + '0'); } return new String(temp); } /** * 拆分字符串 */ public static String[] splitString(String string, int len) { int x = string.length() / len; int y = string.length() % len;