package com.cncounter.util.common;

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

/**
 * Java消息摘要算法 MD5 工具類,其實(shí)其他摘要算法的實(shí)現(xiàn)也類似
 */
public class MD5Util {
 /**
  * 對(duì)文本執(zhí)行 md5 摘要加密, 此算法與 mysql,JavaScript生成的md5摘要進(jìn)行過(guò)一致性對(duì)比.
  * @param plainText
  * @return 返回值中的字母為小寫(xiě)
  */
 public static String md5(String plainText) {
  if (null == plainText) {
   plainText = "";
  }
  String MD5Str = "";
  try {
   // JDK 6 支持以下6種消息摘要算法，不區(qū)分大小寫(xiě)
   // 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;
 }
 // 一個(gè)簡(jiǎn)版測(cè)試
 public static void main(String[] args) {
  String m1 = md5("1");
  String m2 = md5(m1);
  /* 輸出為
   * 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 實(shí)現(xiàn) */

// 括號(hào)表達(dá)式, (xxxxx) 是用來(lái)將內(nèi)部的語(yǔ)句、表達(dá)式的結(jié)果作為一個(gè)結(jié)果.
// 常見(jiàn)的是將json字符串用 eval 解析時(shí),需要 eval("(" +jsonstr+ ")");
// () 內(nèi)部定義了一個(gè)空間, 里面定義的變量不會(huì)污染到全局空間,很適合做lib
// (function UMD(對(duì)象/函數(shù)名name, 上下文this, 函數(shù)/對(duì)象的定義)) 返回一個(gè)匿名函數(shù)
// 因?yàn)榈谝粋€(gè)括號(hào)內(nèi) 的結(jié)果是一個(gè)函數(shù),而函數(shù)可以這樣調(diào)用: (function(形參){})(實(shí)參);
// 這種匿名函數(shù)被瀏覽器解析后會(huì)自動(dòng)執(zhí)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,則將賦值結(jié)果賦給 它
 // 可以不用管
 module.exports = definition();
 } else if ( typeof define === "function" && define.amd) {
 // 如果 define 這個(gè)函數(shù)存在,應(yīng)該是另一個(gè)基礎(chǔ)類庫(kù)，則使用define
 // 可以不用管
 define(definition);
 } else {
 // 簡(jiǎn)單一點(diǎn),可以看成: 調(diào)用傳入的definition函數(shù)，將返回的對(duì)象綁定到全局空間
 // 當(dāng)然,根據(jù)傳入的上下文不同,也可以綁定到其他對(duì)象下面,成為一個(gè)屬性方法.
 context[name] = definition(name, context);
 }
}
)("md5", this, function DEF(name, context) {"use strict";
 // 上面的 use strict 表示嚴(yán)格語(yǔ)法模式,有錯(cuò)誤就拒絕執(zhí)行.
 // 而普通的JS,是解釋執(zhí)行,不執(zhí)行的地方,有些錯(cuò)誤也不影響其他代碼的執(zhí)行
 // 作為類庫(kù),使用嚴(yán)格模式是很有必要的.嚴(yán)格模式聲明必須放到一個(gè)namespace空間的最起始處.

 //
 var old_public_api = (context || {})[name];
 // 最后要返回的對(duì)象/函數(shù).
 function md5_func(text) {
 return hex_md5(text);
 };
 // 下面一堆是具體的算法... 可以先不用管
 /////////////////////////////////////////////////////

 //計(jì)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 >>> 6) & 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, n, m, p[g + 1], 12, -389564586);
 m = md5_ff(m, l, o, n, p[g + 2], 17, 606105819);
 n = md5_ff(n, m, l, o, p[g + 3], 22, -1044525330);
 o = md5_ff(o, n, m, l, p[g + 4], 7, -176418897);
 l = md5_ff(l, o, n, m, p[g + 5], 12, 1200080426);
 m = md5_ff(m, l, o, n, p[g + 6], 17, -1473231341);
 n = md5_ff(n, m, l, o, p[g + 7], 22, -45705983);
 o = md5_ff(o, n, m, l, p[g + 8], 7, 1770035416);
 l = md5_ff(l, o, n, m, p[g + 9], 12, -1958414417);
 m = md5_ff(m, l, o, n, p[g + 10], 17, -42063);
 n = md5_ff(n, m, l, o, p[g + 11], 22, -1990404162);
 o = md5_ff(o, n, m, l, p[g + 12], 7, 1804603682);
 l = md5_ff(l, o, n, m, p[g + 13], 12, -40341101);
 m = md5_ff(m, l, o, n, p[g + 14], 17, -1502002290);
 n = md5_ff(n, m, l, o, p[g + 15], 22, 1236535329);
 o = md5_gg(o, n, m, l, p[g + 1], 5, -165796510);
 l = md5_gg(l, o, n, m, p[g + 6], 9, -1069501632);
 m = md5_gg(m, l, o, n, p[g + 11], 14, 643717713);
 n = md5_gg(n, m, l, o, p[g + 0], 20, -373897302);
 o = md5_gg(o, n, m, l, p[g + 5], 5, -701558691);
 l = md5_gg(l, o, n, m, p[g + 10], 9, 38016083);
 m = md5_gg(m, l, o, n, p[g + 15], 14, -660478335);
 n = md5_gg(n, m, l, o, p[g + 4], 20, -405537848);
 o = md5_gg(o, n, m, l, p[g + 9], 5, 568446438);
 l = md5_gg(l, o, n, m, p[g + 14], 9, -1019803690);
 m = md5_gg(m, l, o, n, p[g + 3], 14, -187363961);
 n = md5_gg(n, m, l, o, p[g + 8], 20, 1163531501);
 o = md5_gg(o, n, m, l, p[g + 13], 5, -1444681467);
 l = md5_gg(l, o, n, m, p[g + 2], 9, -51403784);
 m = md5_gg(m, l, o, n, p[g + 7], 14, 1735328473);
 n = md5_gg(n, m, l, o, p[g + 12], 20, -1926607734);
 o = md5_hh(o, n, m, l, p[g + 5], 4, -378558);
 l = md5_hh(l, o, n, m, p[g + 8], 11, -2022574463);
 m = md5_hh(m, l, o, n, p[g + 11], 16, 1839030562);
 n = md5_hh(n, m, l, o, p[g + 14], 23, -35309556);
 o = md5_hh(o, n, m, l, p[g + 1], 4, -1530992060);
 l = md5_hh(l, o, n, m, p[g + 4], 11, 1272893353);
 m = md5_hh(m, l, o, n, p[g + 7], 16, -155497632);
 n = md5_hh(n, m, l, o, p[g + 10], 23, -1094730640);
 o = md5_hh(o, n, m, l, p[g + 13], 4, 681279174);
 l = md5_hh(l, o, n, m, p[g + 0], 11, -358537222);
 m = md5_hh(m, l, o, n, p[g + 3], 16, -722521979);
 n = md5_hh(n, m, l, o, p[g + 6], 23, 76029189);
 o = md5_hh(o, n, m, l, p[g + 9], 4, -640364487);
 l = md5_hh(l, o, n, m, p[g + 12], 11, -421815835);
 m = md5_hh(m, l, o, n, p[g + 15], 16, 530742520);
 n = md5_hh(n, m, l, o, p[g + 2], 23, -995338651);
 o = md5_ii(o, n, m, l, p[g + 0], 6, -198630844);
 l = md5_ii(l, o, n, m, p[g + 7], 10, 1126891415);
 m = md5_ii(m, l, o, n, p[g + 14], 15, -1416354905);
 n = md5_ii(n, m, l, o, p[g + 5], 21, -57434055);
 o = md5_ii(o, n, m, l, p[g + 12], 6, 1700485571);
 l = md5_ii(l, o, n, m, p[g + 3], 10, -1894986606);
 m = md5_ii(m, l, o, n, p[g + 10], 15, -1051523);
 n = md5_ii(n, m, l, o, p[g + 1], 21, -2054922799);
 o = md5_ii(o, n, m, l, p[g + 8], 6, 1873313359);
 l = md5_ii(l, o, n, m, p[g + 15], 10, -30611744);
 m = md5_ii(m, l, o, n, p[g + 6], 15, -1560198380);
 n = md5_ii(n, m, l, o, p[g + 13], 21, 1309151649);
 o = md5_ii(o, n, m, l, p[g + 4], 6, -145523070);
 l = md5_ii(l, o, n, m, p[g + 11], 10, -1120210379);
 m = md5_ii(m, l, o, n, p[g + 2], 15, 718787259);
 n = md5_ii(n, m, l, o, p[g + 9], 21, -343485551);
 o = safe_add(o, j);
 n = safe_add(n, h);
 m = safe_add(m, f);
 l = safe_add(l, e)
 }
 return Array(o, n, m, 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, e, i, h) {
 return md5_cmn((f & k) | ((~f) & j), g, f, e, i, h)
 };
 function md5_gg(g, f, k, j, e, i, h) {
 return md5_cmn((f & j) | (k & (~j)), g, f, e, i, h)
 };
 function md5_hh(g, f, k, j, e, i, h) {
 return md5_cmn(f ^ k ^ j, g, f, e, i, h)
 };
 function md5_ii(g, f, k, j, e, i, h) {
 return md5_cmn(k ^ (f | (~j)), g, f, e, i, 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))
 };

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

 // 避免全局命名空間沖突
 md5_func.noConflict = function publicAPI$noConflict() {
 if (context) {
 // 將那個(gè) name還原回原來(lái)的對(duì)象
 context[name] = old_public_api;
 }
 // 返回自身,由調(diào)用的代碼自己持有,保存,或賦值給某個(gè)變量
 return md5_func;
 };

 // 返回的對(duì)象,會(huì)被綁定到 MD5 之類的名字上,在外部就引用了此對(duì)象,
 // 因?yàn)殚]包特性,可以利用到閉包內(nèi)部方法和內(nèi)部對(duì)象。 lib一般都是利用這種閉包特性,維護(hù)私有的屬性、對(duì)象,
 // 對(duì)外只暴露一些方法(API),也就是 function, 外面只能調(diào)用這些API,方便內(nèi)部進(jìn)行邏輯控制,降低依賴.
 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