燕哥带你学算法 2012-04-18
import javax.crypto.Cipher; import javax.crypto.spec.IvParameterSpec; import javax.crypto.spec.SecretKeySpec; /** * AES加解密算法(使用Base64做转码以及辅助加密) * */ public class AES { private static byte[] iv = { 0, 1, 0, 2, 0, 3, 0, 4, 0, 5, 0, 6, 0, 7, 0, 8 }; /** * 加密 * * @param encryptString * @param encryptKey 密钥 * @return * @throws Exception */ public static String encryptAES(String encryptString, String encryptKey) throws Exception { IvParameterSpec zeroIv = new IvParameterSpec(iv); SecretKeySpec key = new SecretKeySpec(encryptKey.getBytes(), "AES"); // 算法/模式/补码方式 Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding"); cipher.init(Cipher.ENCRYPT_MODE, key, zeroIv); byte[] encryptedData = cipher.doFinal(encryptString.getBytes()); return Base64.encode(encryptedData); } /** * 解密 * * @param decryptString * @param decryptKey 密钥 * @return * @throws Exception */ public static String decryptAES(String decryptString, String decryptKey) throws Exception { byte[] byteMi = Base64.decode(decryptString); IvParameterSpec zeroIv = new IvParameterSpec(iv); SecretKeySpec key = new SecretKeySpec(decryptKey.getBytes(), "AES"); Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding"); cipher.init(Cipher.DECRYPT_MODE, key, zeroIv); byte decryptedData[] = cipher.doFinal(byteMi); return new String(decryptedData); } }
import java.io.ByteArrayOutputStream; import java.io.IOException; import java.io.OutputStream; public class Base64 { private static final char[] legalChars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/".toCharArray(); /** * data[]进行编码 * * @param data * @return */ public static String encode(byte[] data) { int start = 0; int len = data.length; StringBuffer buf = new StringBuffer(data.length * 3 / 2); int end = len - 3; int i = start; int n = 0; while (i <= end) { int d = ((((int) data[i]) & 0x0ff) << 16) | ((((int) data[i + 1]) & 0x0ff) << 8) | (((int) data[i + 2]) & 0x0ff); buf.append(legalChars[(d >> 18) & 63]); buf.append(legalChars[(d >> 12) & 63]); buf.append(legalChars[(d >> 6) & 63]); buf.append(legalChars[d & 63]); i += 3; if (n++ >= 14) { n = 0; buf.append(" "); } } if (i == start + len - 2) { int d = ((((int) data[i]) & 0x0ff) << 16) | ((((int) data[i + 1]) & 255) << 8); buf.append(legalChars[(d >> 18) & 63]); buf.append(legalChars[(d >> 12) & 63]); buf.append(legalChars[(d >> 6) & 63]); buf.append("="); } else if (i == start + len - 1) { int d = (((int) data[i]) & 0x0ff) << 16; buf.append(legalChars[(d >> 18) & 63]); buf.append(legalChars[(d >> 12) & 63]); buf.append("=="); } return buf.toString(); } private static int decode(char c) { if (c >= 'A' && c <= 'Z') return ((int) c) - 65; else if (c >= 'a' && c <= 'z') return ((int) c) - 97 + 26; else if (c >= '0' && c <= '9') return ((int) c) - 48 + 26 + 26; else switch (c) { case '+': return 62; case '/': return 63; case '=': return 0; default: throw new RuntimeException("unexpected code: " + c); } } /** * Decodes the given Base64 encoded String to a new byte array. The byte array holding the decoded data is returned. */ public static byte[] decode(String s) { ByteArrayOutputStream bos = new ByteArrayOutputStream(); try { decode(s, bos); } catch (IOException e) { throw new RuntimeException(); } byte[] decodedBytes = bos.toByteArray(); try { bos.close(); bos = null; } catch (IOException ex) { System.err.println("Error while decoding BASE64: " + ex.toString()); } return decodedBytes; } private static void decode(String s, OutputStream os) throws IOException { int i = 0; int len = s.length(); while (true) { while (i < len && s.charAt(i) <= ' ') i++; if (i == len) break; int tri = (decode(s.charAt(i)) << 18) + (decode(s.charAt(i + 1)) << 12) + (decode(s.charAt(i + 2)) << 6) + (decode(s.charAt(i + 3))); os.write((tri >> 16) & 255); if (s.charAt(i + 2) == '=') break; os.write((tri >> 8) & 255); if (s.charAt(i + 3) == '=') break; os.write(tri & 255); i += 4; } } }
public class Test { public static void main(String[] args) { // 密钥 String key = "liuyq@lexinag100"; // 文本 String text = "{records:2,person:[{name:'Mr.Z',age:25},{name:'张三',age:29}]}"; try { // 对文本进行加密 String result1 = AES.encryptAES(text, key); // 对加密文本进行解密 String result2 = AES.decryptAES(result1, key); System.out.println("加密前:" + text); System.out.println("加密后:" + result1); System.out.println("解密后:" + result2); } catch (Exception e) { e.printStackTrace(); } } }