package com.cncounter.util.common;

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

/**
 * Java消息摘要算法 MD5 工具类,其实其他摘要算法的实现也类似
 */
public class MD5Util {
 /**
  * 对文本执行 md5 摘要加密,此算法与 MysqL,JavaScript生成的md5摘要进行过一致性对比.
  * @param plainText
  * @return 返回值中的字母为小写
  */
 public static String md5(String plainText) {
  if (null == plainText) {
   plainText = "";
  }
  String MD5Str = "";
  try {
   // JDK 6 支持以下6种消息摘要算法，不区分大小写
   // md5,sha(sha-1),md2,sha-256,sha-384,sha-512
   MessageDigest md = MessageDigest.getInstance("MD5");
   md.update(plainText.getBytes());
   byte b[] = md.digest();

   int i;

   StringBuilder builder = new StringBuilder(32);
   for (int offset = 0; offset < b.length; offset++) {
    i = b[offset];
    if (i < 0)
     i += 256;
    if (i < 16)
     builder.append("0");
    builder.append(Integer.toHexString(i));
   }
   MD5Str = builder.toString();
   // LogUtil.println("result: " + buf.toString());// 32位的加密
  } catch (NoSuchAlgorithmException e) {
   e.printStackTrace();
  }
  return MD5Str;
 }
 // 一个简版测试
 public static void main(String[] args) {
  String m1 = md5("1");
  String m2 = md5(m1);
  /* 输出为
   * m1=c4ca4238a0b923820dcc509a6f75849b
   * m2=28c8edde3d61a0411511d3b1866f0636
   */
  System.out.println("m1="+m1);
  System.out.println("m2="+m2);
 }
}

select md5('1') as m1,md5(md5('1')) as m2;

MariaDB [(none)]> select md5('1') as m1,md5(md5('1')) as m2;
+----------------------------------+----------------------------------+
| m1        | m2        |
+----------------------------------+----------------------------------+
| c4ca4238a0b923820dcc509a6f75849b | 28c8edde3d61a0411511d3b1866f0636 |
+----------------------------------+----------------------------------+
1 row in set (0.00 sec)

/*! JavaScript 的 MD5 实现 */

// 括号表达式,(xxxxx) 是用来将内部的语句、表达式的结果作为一个结果.
// 常见的是将json字符串用 eval 解析时,需要 eval("(" +jsonstr+ ")");
// () 内部定义了一个空间,里面定义的变量不会污染到全局空间,很适合做lib
// (function UMD(对象/函数名name,上下文this,函数/对象的定义)) 返回一个匿名函数
// 因为第一个括号内 的结果是一个函数,而函数可以这样调用: (function(形参){})(实参);
// 这种匿名函数被浏览器解析后会自动执行一次.
(function UMD(name,context,definition) {
 if ( typeof module !== "undefined" && module.exports) {
 // 如果 module 存在,并且module.exports存在,则将赋值结果赋给 它
 // 可以不用管
 module.exports = definition();
 } else if ( typeof define === "function" && define.amd) {
 // 如果 define 这个函数存在,应该是另一个基础类库，则使用define
 // 可以不用管
 define(definition);
 } else {
 // 简单一点,可以看成: 调用传入的definition函数，将返回的对象绑定到全局空间
 // 当然,根据传入的上下文不同,也可以绑定到其他对象下面,成为一个属性方法.
 context[name] = definition(name,context);
 }
}
)("md5",this,function DEF(name,context) {"use strict";
 // 上面的 use strict 表示严格语法模式,有错误就拒绝执行.
 // 而普通的JS,是解释执行,不执行的地方,有些错误也不影响其他代码的执行
 // 作为类库,使用严格模式是很有必要的.严格模式声明必须放到一个namespace空间的最起始处.

 //
 var old_public_api = (context || {})[name];
 // 最后要返回的对象/函数.
 function md5_func(text) {
 return hex_md5(text);
 };
 // 下面一堆是具体的算法... 可以先不用管
 /////////////////////////////////////////////////////

 //计算MD5
 var hexcase = 0;
 function hex_md5(a) {
 if (a == "")
 return a;
 return rstr2hex(rstr_md5(str2rstr_utf8(a)))
 };
 function hex_hmac_md5(a,b) {
 return rstr2hex(rstr_hmac_md5(str2rstr_utf8(a),str2rstr_utf8(b)))
 };
 function md5_vm_test() {
 return hex_md5("abc").toLowerCase() == "900150983cd24fb0d6963f7d28e17f72"
 };
 function rstr_md5(a) {
 return binl2rstr(binl_md5(rstr2binl(a),a.length * 8))
 };
 function rstr_hmac_md5(c,f) {
 var e = rstr2binl(c);
 if (e.length > 16) {
 e = binl_md5(e,c.length * 8)
 }
 var a = Array(16),d = Array(16);
 for (var b = 0; b < 16; b++) {
 a[b] = e[b] ^ 909522486;
 d[b] = e[b] ^ 1549556828
 }
 var g = binl_md5(a.concat(rstr2binl(f)),512 + f.length * 8);
 return binl2rstr(binl_md5(d.concat(g),512 + 128))
 };
 function rstr2hex(c) {
 try { hexcase
 } catch(g) {
 hexcase = 0
 }
 var f = hexcase ? "0123456789ABCDEF" : "0123456789abcdef";
 var b = "";
 var a;
 for (var d = 0; d < c.length; d++) {
 a = c.charCodeAt(d);
 b += f.charAt((a >>> 4) & 15) + f.charAt(a & 15)
 }
 return b
 };
 function str2rstr_utf8(c) {
 var b = "";
 var d = -1;
 var a,e;
 while (++d < c.length) {
 a = c.charCodeAt(d);
 e = d + 1 < c.length ? c.charCodeAt(d + 1) : 0;
 if (55296 <= a && a <= 56319 && 56320 <= e && e <= 57343) {
 a = 65536 + ((a & 1023) << 10) + (e & 1023);
 d++
 }
 if (a <= 127) {
 b += String.fromCharCode(a)
 } else {
 if (a <= 2047) {
  b += String.fromCharCode(192 | ((a >>> 6) & 31),128 | (a & 63))
 } else {
  if (a <= 65535) {
  b += String.fromCharCode(224 | ((a >>> 12) & 15),128 | ((a >>> 6) & 63),128 | (a & 63))
  } else {
  if (a <= 2097151) {
  b += String.fromCharCode(240 | ((a >>> 18) & 7),128 | ((a >>> 12) & 63),128 | (a & 63))
  }
  }
 }
 }
 }
 return b
 };
 function rstr2binl(b) {
 var a = Array(b.length >> 2);
 for (var c = 0; c < a.length; c++) {
 a[c] = 0
 }
 for (var c = 0; c < b.length * 8; c += 8) {
 a[c >> 5] |= (b.charCodeAt(c / 8) & 255) << (c % 32)
 }
 return a
 };
 function binl2rstr(b) {
 var a = "";
 for (var c = 0; c < b.length * 32; c += 8) {
 a += String.fromCharCode((b[c >> 5] >>> (c % 32)) & 255)
 }
 return a
 };
 function binl_md5(p,k) {
 p[k >> 5] |= 128 << ((k) % 32);
 p[(((k + 64) >>> 9) << 4) + 14] = k;
 var o = 1732584193;
 var n = -271733879;
 var m = -1732584194;
 var l = 271733878;
 for (var g = 0; g < p.length; g += 16) {
 var j = o;
 var h = n;
 var f = m;
 var e = l;
 o = md5_ff(o,n,m,l,p[g + 0],7,-680876936);
 l = md5_ff(l,o,p[g + 1],12,-389564586);
 m = md5_ff(m,p[g + 2],17,606105819);
 n = md5_ff(n,p[g + 3],22,-1044525330);
 o = md5_ff(o,p[g + 4],-176418897);
 l = md5_ff(l,p[g + 5],1200080426);
 m = md5_ff(m,p[g + 6],-1473231341);
 n = md5_ff(n,p[g + 7],-45705983);
 o = md5_ff(o,p[g + 8],1770035416);
 l = md5_ff(l,p[g + 9],-1958414417);
 m = md5_ff(m,p[g + 10],-42063);
 n = md5_ff(n,p[g + 11],-1990404162);
 o = md5_ff(o,p[g + 12],1804603682);
 l = md5_ff(l,p[g + 13],-40341101);
 m = md5_ff(m,p[g + 14],-1502002290);
 n = md5_ff(n,p[g + 15],1236535329);
 o = md5_gg(o,5,-165796510);
 l = md5_gg(l,9,-1069501632);
 m = md5_gg(m,14,643717713);
 n = md5_gg(n,20,-373897302);
 o = md5_gg(o,-701558691);
 l = md5_gg(l,38016083);
 m = md5_gg(m,-660478335);
 n = md5_gg(n,-405537848);
 o = md5_gg(o,568446438);
 l = md5_gg(l,-1019803690);
 m = md5_gg(m,-187363961);
 n = md5_gg(n,1163531501);
 o = md5_gg(o,-1444681467);
 l = md5_gg(l,-51403784);
 m = md5_gg(m,1735328473);
 n = md5_gg(n,-1926607734);
 o = md5_hh(o,4,-378558);
 l = md5_hh(l,11,-2022574463);
 m = md5_hh(m,16,1839030562);
 n = md5_hh(n,23,-35309556);
 o = md5_hh(o,-1530992060);
 l = md5_hh(l,1272893353);
 m = md5_hh(m,-155497632);
 n = md5_hh(n,-1094730640);
 o = md5_hh(o,681279174);
 l = md5_hh(l,-358537222);
 m = md5_hh(m,-722521979);
 n = md5_hh(n,76029189);
 o = md5_hh(o,-640364487);
 l = md5_hh(l,-421815835);
 m = md5_hh(m,530742520);
 n = md5_hh(n,-995338651);
 o = md5_ii(o,6,-198630844);
 l = md5_ii(l,10,1126891415);
 m = md5_ii(m,15,-1416354905);
 n = md5_ii(n,21,-57434055);
 o = md5_ii(o,1700485571);
 l = md5_ii(l,-1894986606);
 m = md5_ii(m,-1051523);
 n = md5_ii(n,-2054922799);
 o = md5_ii(o,1873313359);
 l = md5_ii(l,-30611744);
 m = md5_ii(m,-1560198380);
 n = md5_ii(n,1309151649);
 o = md5_ii(o,-145523070);
 l = md5_ii(l,-1120210379);
 m = md5_ii(m,718787259);
 n = md5_ii(n,-343485551);
 o = safe_add(o,j);
 n = safe_add(n,h);
 m = safe_add(m,f);
 l = safe_add(l,e)
 }
 return Array(o,l)
 };
 function md5_cmn(h,e,d,c,g,f) {
 return safe_add(bit_rol(safe_add(safe_add(e,h),safe_add(c,f)),g),d)
 };
 function md5_ff(g,f,k,j,i,h) {
 return md5_cmn((f & k) | ((~f) & j),h)
 };
 function md5_gg(g,h) {
 return md5_cmn((f & j) | (k & (~j)),h)
 };
 function md5_hh(g,h) {
 return md5_cmn(f ^ k ^ j,h)
 };
 function md5_ii(g,h) {
 return md5_cmn(k ^ (f | (~j)),h)
 };
 function safe_add(a,d) {
 var c = (a & 65535) + (d & 65535);
 var b = (a >> 16) + (d >> 16) + (c >> 16);
 return (b << 16) | (c & 65535)
 };
 function bit_rol(a,b) {
 return (a << b) | (a >>> (32 - b))
 };

 /////////////////////////////////////////////////////

 // 避免全局命名空间冲突
 md5_func.noConflict = function publicAPI$noConflict() {
 if (context) {
 // 将那个 name还原回原来的对象
 context[name] = old_public_api;
 }
 // 返回自身,由调用的代码自己持有,保存,或赋值给某个变量
 return md5_func;
 };

 // 返回的对象,会被绑定到 MD5 之类的名字上,在外部就引用了此对象,// 因为闭包特性,可以利用到闭包内部方法和内部对象。 lib一般都是利用这种闭包特性,维护私有的属性、对象,// 对外只暴露一些方法(API),也就是 function,外面只能调用这些API,方便内部进行逻辑控制,降低依赖.
 return md5_func;
})

md5("1");
"c4ca4238a0b923820dcc509a6f75849b"
md5(md5("1"))
"28c8edde3d61a0411511d3b1866f0636"

CREATE OR REPLACE FUNCTION MD5(passwd IN VARCHAR2) RETURN VARCHAR2 IS
 retval varchar2(32);
BEGIN
 retval := Lower(utl_raw.cast_to_raw(
DBMS_OBFUSCATION_TOOLKIT.MD5(INPUT_STRING => passwd))
);
 RETURN retval;
END;

sql> select MD5('1') as m1,MD5(md5('1')) as m2 from dual
 2 ;

M1
---------------------------------------
M2
---------------------------------------
c4ca4238a0b923820dcc509a6f75849b
28c8edde3d61a0411511d3b1866f0636