java加密之AES/ECB/PKCS5Padding

废话不多说，直接上代码

1.先创建一个base64编码类，

实际项目中不用自己写，有成熟的实现方法

package com.taikang;public final class Base64 { static private final int     BASELENGTH           = 128;  static private final int     LOOKUPLENGTH         = 64;  static private final int     TWENTYFOURBITGROUP   = 24;  static private final int     EIGHTBIT             = 8;  static private final int     SIXTEENBIT           = 16;  static private final int     FOURBYTE             = 4;  static private final int     SIGN                 = -128;  static private final char    PAD                  = '=';  static private final boolean fDebug               = false;  static final private byte[]  base64Alphabet       = new byte[BASELENGTH];  static final private char[]  lookUpBase64Alphabet = new char[LOOKUPLENGTH];  static {      for (int i = 0; i < BASELENGTH; ++i) {          base64Alphabet[i] = -1;      }      for (int i = 'Z'; i >= 'A'; i--) {          base64Alphabet[i] = (byte) (i - 'A');      }      for (int i = 'z'; i >= 'a'; i--) {          base64Alphabet[i] = (byte) (i - 'a' + 26);      }      for (int i = '9'; i >= '0'; i--) {          base64Alphabet[i] = (byte) (i - '0' + 52);      }      base64Alphabet['+'] = 62;      base64Alphabet['/'] = 63;      for (int i = 0; i <= 25; i++) {          lookUpBase64Alphabet[i] = (char) ('A' + i);      }      for (int i = 26, j = 0; i <= 51; i++, j++) {          lookUpBase64Alphabet[i] = (char) ('a' + j);      }      for (int i = 52, j = 0; i <= 61; i++, j++) {          lookUpBase64Alphabet[i] = (char) ('0' + j);      }      lookUpBase64Alphabet[62] = (char) '+';      lookUpBase64Alphabet[63] = (char) '/';  }  private static boolean isWhiteSpace(char octect) {      return (octect == 0x20 || octect == 0xd || octect == 0xa || octect == 0x9);  }  private static boolean isPad(char octect) {      return (octect == PAD);  }  private static boolean isData(char octect) {      return (octect < BASELENGTH && base64Alphabet[octect] != -1);  }  /**  * Encodes hex octects into Base64  *  * @param binaryData Array containing binaryData  * @return Encoded Base64 array  */  public static String encode(byte[] binaryData) {      if (binaryData == null) {          return null;      }      int lengthDataBits = binaryData.length * EIGHTBIT;      if (lengthDataBits == 0) {          return "";      }      int fewerThan24bits = lengthDataBits % TWENTYFOURBITGROUP;      int numberTriplets = lengthDataBits / TWENTYFOURBITGROUP;      int numberQuartet = fewerThan24bits != 0 ? numberTriplets + 1 : numberTriplets;      char encodedData[] = null;      encodedData = new char[numberQuartet * 4];      byte k = 0, l = 0, b1 = 0, b2 = 0, b3 = 0;      int encodedIndex = 0;      int dataIndex = 0;      if (fDebug) {          System.out.println("number of triplets = " + numberTriplets);      }      for (int i = 0; i < numberTriplets; i++) {          b1 = binaryData[dataIndex++];          b2 = binaryData[dataIndex++];          b3 = binaryData[dataIndex++];          if (fDebug) {              System.out.println("b1= " + b1 + ", b2= " + b2 + ", b3= " + b3);          }          l = (byte) (b2 & 0x0f);          k = (byte) (b1 & 0x03);          byte val1 = ((b1 & SIGN) == 0) ? (byte) (b1 >> 2) : (byte) ((b1) >> 2 ^ 0xc0);          byte val2 = ((b2 & SIGN) == 0) ? (byte) (b2 >> 4) : (byte) ((b2) >> 4 ^ 0xf0);          byte val3 = ((b3 & SIGN) == 0) ? (byte) (b3 >> 6) : (byte) ((b3) >> 6 ^ 0xfc);          if (fDebug) {              System.out.println("val2 = " + val2);              System.out.println("k4   = " + (k << 4));              System.out.println("vak  = " + (val2 | (k << 4)));          }          encodedData[encodedIndex++] = lookUpBase64Alphabet[val1];          encodedData[encodedIndex++] = lookUpBase64Alphabet[val2 | (k << 4)];          encodedData[encodedIndex++] = lookUpBase64Alphabet[(l << 2) | val3];          encodedData[encodedIndex++] = lookUpBase64Alphabet[b3 & 0x3f];      }      // form integral number of 6-bit groups      if (fewerThan24bits == EIGHTBIT) {          b1 = binaryData[dataIndex];          k = (byte) (b1 & 0x03);          if (fDebug) {              System.out.println("b1=" + b1);              System.out.println("b1<<2 = " + (b1 >> 2));          }          byte val1 = ((b1 & SIGN) == 0) ? (byte) (b1 >> 2) : (byte) ((b1) >> 2 ^ 0xc0);          encodedData[encodedIndex++] = lookUpBase64Alphabet[val1];          encodedData[encodedIndex++] = lookUpBase64Alphabet[k << 4];          encodedData[encodedIndex++] = PAD;          encodedData[encodedIndex++] = PAD;      } else if (fewerThan24bits == SIXTEENBIT) {          b1 = binaryData[dataIndex];          b2 = binaryData[dataIndex + 1];          l = (byte) (b2 & 0x0f);          k = (byte) (b1 & 0x03);          byte val1 = ((b1 & SIGN) == 0) ? (byte) (b1 >> 2) : (byte) ((b1) >> 2 ^ 0xc0);          byte val2 = ((b2 & SIGN) == 0) ? (byte) (b2 >> 4) : (byte) ((b2) >> 4 ^ 0xf0);          encodedData[encodedIndex++] = lookUpBase64Alphabet[val1];          encodedData[encodedIndex++] = lookUpBase64Alphabet[val2 | (k << 4)];          encodedData[encodedIndex++] = lookUpBase64Alphabet[l << 2];          encodedData[encodedIndex++] = PAD;      }      return new String(encodedData);  }  /**  * Decodes Base64 data into octects  *  * @param encoded string containing Base64 data  * @return Array containind decoded data.  */  public static byte[] decode(String encoded) {      if (encoded == null) {          return null;      }      char[] base64Data = encoded.toCharArray();      // remove white spaces      int len = removeWhiteSpace(base64Data);      if (len % FOURBYTE != 0) {          return null;//should be divisible by four      }      int numberQuadruple = (len / FOURBYTE);      if (numberQuadruple == 0) {          return new byte[0];      }      byte decodedData[] = null;      byte b1 = 0, b2 = 0, b3 = 0, b4 = 0;      char d1 = 0, d2 = 0, d3 = 0, d4 = 0;      int i = 0;      int encodedIndex = 0;      int dataIndex = 0;      decodedData = new byte[(numberQuadruple) * 3];      for (; i < numberQuadruple - 1; i++) {          if (!isData((d1 = base64Data[dataIndex++])) || !isData((d2 = base64Data[dataIndex++]))              || !isData((d3 = base64Data[dataIndex++]))              || !isData((d4 = base64Data[dataIndex++]))) {              return null;          }//if found "no data" just return null          b1 = base64Alphabet[d1];          b2 = base64Alphabet[d2];          b3 = base64Alphabet[d3];          b4 = base64Alphabet[d4];          decodedData[encodedIndex++] = (byte) (b1 << 2 | b2 >> 4);          decodedData[encodedIndex++] = (byte) (((b2 & 0xf) << 4) | ((b3 >> 2) & 0xf));          decodedData[encodedIndex++] = (byte) (b3 << 6 | b4);      }      if (!isData((d1 = base64Data[dataIndex++])) || !isData((d2 = base64Data[dataIndex++]))) {          return null;//if found "no data" just return null      }      b1 = base64Alphabet[d1];      b2 = base64Alphabet[d2];      d3 = base64Data[dataIndex++];      d4 = base64Data[dataIndex++];      if (!isData((d3)) || !isData((d4))) {//Check if they are PAD characters          if (isPad(d3) && isPad(d4)) {              if ((b2 & 0xf) != 0)//last 4 bits should be zero              {                  return null;              }              byte[] tmp = new byte[i * 3 + 1];              System.arraycopy(decodedData, 0, tmp, 0, i * 3);              tmp[encodedIndex] = (byte) (b1 << 2 | b2 >> 4);              return tmp;          } else if (!isPad(d3) && isPad(d4)) {              b3 = base64Alphabet[d3];              if ((b3 & 0x3) != 0)//last 2 bits should be zero              {                  return null;              }              byte[] tmp = new byte[i * 3 + 2];              System.arraycopy(decodedData, 0, tmp, 0, i * 3);              tmp[encodedIndex++] = (byte) (b1 << 2 | b2 >> 4);              tmp[encodedIndex] = (byte) (((b2 & 0xf) << 4) | ((b3 >> 2) & 0xf));              return tmp;          } else {              return null;          }      } else { //No PAD e.g 3cQl          b3 = base64Alphabet[d3];          b4 = base64Alphabet[d4];          decodedData[encodedIndex++] = (byte) (b1 << 2 | b2 >> 4);          decodedData[encodedIndex++] = (byte) (((b2 & 0xf) << 4) | ((b3 >> 2) & 0xf));          decodedData[encodedIndex++] = (byte) (b3 << 6 | b4);      }      return decodedData;  }  /**  * remove WhiteSpace from MIME containing encoded Base64 data.  *  * @param data  the byte array of base64 data (with WS)  * @return      the new length  */  private static int removeWhiteSpace(char[] data) {      if (data == null) {          return 0;      }      // count characters that's not whitespace      int newSize = 0;      int len = data.length;      for (int i = 0; i < len; i++) {          if (!isWhiteSpace(data[i])) {              data[newSize++] = data[i];          }      }      return newSize;  }  } 

2.AES/ECB/PKCS5Padding加密算法

// 加密    public static String Encrypt(String sSrc, String sKey) throws Exception {        if (sKey == null) {            System.out.print("Key为空null");            return null;        }        // 判断Key是否为16位        if (sKey.length() != 16) {            System.out.print("Key长度不是16位");            return null;        }        byte[] raw = sKey.getBytes("utf-8");        SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES");        Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5Padding");//"算法/模式/补码方式"        cipher.init(Cipher.ENCRYPT_MODE, skeySpec);        byte[] encrypted = cipher.doFinal(sSrc.getBytes("utf-8"));        return new Base64().encode(encrypted);//此处使用BASE64做转码功能，同时能起到2次加密的作用。    }

3.解密算法

// 解密    public static String Decrypt(String sSrc, String sKey) throws Exception {        try {            // 判断Key是否正确            if (sKey == null) {                System.out.print("Key为空null");                return null;            }            // 判断Key是否为16位            if (sKey.length() != 16) {                System.out.print("Key长度不是16位");                return null;            }            byte[] raw = sKey.getBytes("utf-8");            SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES");            Cipher cipher = Cipher.getInstance("AES/ECB/PKCS5Padding");            cipher.init(Cipher.DECRYPT_MODE, skeySpec);            byte[] encrypted1 = new Base64().decode(sSrc);//先用base64解密            try {                byte[] original = cipher.doFinal(encrypted1);                String originalString = new String(original,"utf-8");                return originalString;            } catch (Exception e) {                System.out.println(e.toString());                return null;            }        } catch (Exception ex) {            System.out.println(ex.toString());            return null;        }    }

4.测试

 public static void main(String[] args) throws Exception {        /*         * 此处使用AES-128-ECB加密模式，key需要为16位。         */        String cKey = "123456789012345";        // 需要加密的字串        String cSrc = "www.taikang.com 你好";        System.out.println(cSrc);        // 加密        String enString = AES.Encrypt(cSrc, cKey);        System.out.println("加密后的字串是：" + enString);        // 解密        String DeString = AES.Decrypt(enString, cKey);        System.out.println("解密后的字串是：" + DeString);    }

5.运行结果

www.taikang.com 你好加密后的字串是：8mmGTqzo8REZveq3PiZvs+pJc8cFrFW9WBUWztLOqsg=解密后的字串是：www.taikang.com 你好

说明：这种方式加密解密双方使用同一个密钥，这个密钥可以在数据库报存，也可以在配置文件，或者在常量类中看个人喜好