一：MD5 方法js

更多md5相關內容，可以查看此帖：MD5加密中文的結果不一致 
生成的文件可以放在 utils文件中哦?。?！

1. /*
2. * A JavaScript implementation of the RSA Data Security, Inc. MD5 Message
3. * Digest Algorithm, as defined in RFC 1321.
4. * Version 1.1 Copyright (C) Paul Johnston 1999 - 2002.
5. * Code also contributed by Greg Holt
6. * See http://pajhome.org.uk/site/legal.html for details.
7. */
8.  
9. /*
10. * Add integers, wrapping at 2^32. This uses 16-bit operations internally
11. * to work around bugs in some JS interpreters.
12. */
13. function safe_add(x, y)
14. {
15. var lsw = (x & 0xFFFF) + (y & 0xFFFF)
16. var msw = (x >> 16) + (y >> 16) + (lsw >> 16)
17. return (msw << 16) | (lsw & 0xFFFF)
18. }
19.  
20. /*
21. * Bitwise rotate a 32-bit number to the left.
22. */
23. function rol(num, cnt)
24. {
25. return (num << cnt) | (num >>> (32 - cnt))
26. }
27.  
28. /*
29. * These functions implement the four basic operations the algorithm uses.
30. */
31. function cmn(q, a, b, x, s, t)
32. {
33. return safe_add(rol(safe_add(safe_add(a, q), safe_add(x, t)), s), b)
34. }
35. function ff(a, b, c, d, x, s, t)
36. {
37. return cmn((b & c) | ((~b) & d), a, b, x, s, t)
38. }
39. function gg(a, b, c, d, x, s, t)
40. {
41. return cmn((b & d) | (c & (~d)), a, b, x, s, t)
42. }
43. function hh(a, b,