一般情况我们都是php加密再由php解密了,但是我的工作就碰到了必须由php加密然后由js来解密了,这种情况我找到一站长写的例子,非常的优秀下面我们一起来看看.

PHP加密函数,代码如下:

1. <?php
2. function strencode($string) {
3. $string = base64_encode($string);
4. $key = md5('just a test');
5. $len = strlen($key);
6. $code = '';
7. for ($i = 0; $i < strlen($string); $i++) {
8. $k = $i % $len;
9. $code .= $string [$i] ^ $key [$k];
10. }
11. return base64_encode($code);
12. }
13. //开源代码phpfensi.com
14. echo strencode('just a test');
15. ?>

JS:解密,代码如下:

1. <script src="md5.js"></script>
2. <script src="base64.js"></script>
3. <script>
4. function strencode(string) {
5. key =md5('just a test');
6. string = Base64.decode(string);
7. len = key.length;
8. code = '';
9. for (i = 0; i < string.length; i++) {
10. k = i % len;
11. code += String.fromCharCode(string.charCodeAt(i) ^ key.charCodeAt(k));
12. }
13. return Base64.decode(code);
14. }
15. alert(strencode('U1s1TFN3IQ0reTZbBgJlCA===='));
16. </script>

js MD5,代码如下:

1. /*
2. * Configurable variables. You may need to tweak these to be compatible with
3. * the server-side, but the defaults work in most cases.
4. */
5. var hexcase = 0; /* hex output format. 0 - lowercase; 1 - uppercase */
6. var b64pad = ""; /* base-64 pad character. "=" for strict RFC compliance */
7. /*
8. * These are the functions you'll usually want to call
9. * They take string arguments and return either hex or base-64 encoded strings
10. */
11. function md5(s) {
12. return rstr2hex(rstr_md5(str2rstr_utf8(s)));
13. }
14. function b64_md5(s) {
15. return rstr2b64(rstr_md5(str2rstr_utf8(s)));
16. }
17. function any_md5(s, e) {
18. return rstr2any(rstr_md5(str2rstr_utf8(s)), e);
19. }
20. function hex_hmac_md5(k, d)
21. {
22. return rstr2hex(rstr_hmac_md5(str2rstr_utf8(k), str2rstr_utf8(d)));
23. }
24. function b64_hmac_md5(k, d)
25. {
26. return rstr2b64(rstr_hmac_md5(str2rstr_utf8(k), str2rstr_utf8(d)));
27. }
28. function any_hmac_md5(k, d, e)
29. {
30. return rstr2any(rstr_hmac_md5(str2rstr_utf8(k), str2rstr_utf8(d)), e);
31. }
32. /*
33. * Perform a simple self-test to see if the VM is working
34. */
35. function md5_vm_test()
36. {
37. return hex_md5("abc").toLowerCase() == "900150983cd24fb0d6963f7d28e17f72";
38. }
39. /*
40. * Calculate the MD5 of a raw string
41. */
42. function rstr_md5(s)
43. {
44. return binl2rstr(binl_md5(rstr2binl(s), s.length * 8));
45. }
46. /*
47. * Calculate the HMAC-MD5, of a key and some data (raw strings)
48. */
49. function rstr_hmac_md5(key, data)
50. {
51. var bkey = rstr2binl(key);
52. if(bkey.length > 16) bkey = binl_md5(bkey, key.length * 8);
53. var ipad = Array(16), opad = Array(16);
54. for(var i = 0; i < 16; i++)
55. {
56. ipad[i] = bkey[i] ^ 0x36363636;
57. opad[i] = bkey[i] ^ 0x5C5C5C5C;
58. }
59. var hash = binl_md5(ipad.concat(rstr2binl(data)), 512 + data.length * 8);
60. return binl2rstr(binl_md5(opad.concat(hash), 512 + 128));
61. }
62. /*
63. * Convert a raw string to a hex string
64. */
65. function rstr2hex(input)
66. {
67. try {
68. hexcase
69. } catch(e) {
70. hexcase=0;
71. }
72. var hex_tab = hexcase ? "0123456789ABCDEF" : "0123456789abcdef";
73. var output = "";
74. var x;
75. for(var i = 0; i < input.length; i++)
76. {
77. x = input.charCodeAt(i);
78. output += hex_tab.charAt((x >>> 4) & 0x0F)
79. + hex_tab.charAt( x & 0x0F);
80. }
81. return output;
82. }
83. /*
84. * Convert a raw string to a base-64 string
85. */
86. function rstr2b64(input)
87. {
88. try {
89. b64pad
90. } catch(e) {
91. b64pad='';
92. }
93. var tab = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
94. var output = "";
95. var len = input.length;
96. for(var i = 0; i < len; i += 3)
97. {
98. var triplet = (input.charCodeAt(i) << 16)
99. | (i + 1 < len ? input.charCodeAt(i+1) << 8 : 0)
100. | (i + 2 < len ? input.charCodeAt(i+2) : 0);
101. for(var j = 0; j < 4; j++)
102. {
103. if(i * 8 + j * 6 > input.length * 8) output += b64pad;
104. else output += tab.charAt((triplet >>> 6*(3-j)) & 0x3F);
105. }
106. }
107. return output;
108. }
109. /*
110. * Convert a raw string to an arbitrary string encoding
111. */
112. function rstr2any(input, encoding)
113. {
114. var divisor = encoding.length;
115. var i, j, q, x, quotient;
116. /* Convert to an array of 16-bit big-endian values, forming the dividend */
117. var dividend = Array(Math.ceil(input.length / 2));
118. for(i = 0; i < dividend.length; i++)
119. {
120. dividend[i] = (input.charCodeAt(i * 2) << 8) | input.charCodeAt(i * 2 + 1);
121. }
122. /*
123. * Repeatedly perform a long division. The binary array forms the dividend,
124. * the length of the encoding is the divisor. Once computed, the quotient
125. * forms the dividend for the next step. All remainders are stored for later
126. * use.
127. */
128. var full_length = Math.ceil(input.length * 8 /
129. (Math.log(encoding.length) / Math.log(2)));
130. var remainders = Array(full_length);
131. for(j = 0; j < full_length; j++)
132. {
133. quotient = Array();
134. x = 0;
135. for(i = 0; i < dividend.length; i++)
136. {
137. x = (x << 16) + dividend[i];
138. q = Math.floor(x / divisor);
139. x -= q * divisor;
140. if(quotient.length > 0 || q > 0)
141. quotient[quotient.length] = q;
142. }
143. remainders[j] = x;
144. dividend = quotient;
145. }
146. /* Convert the remainders to the output string */
147. var output = "";
148. for(i = remainders.length - 1; i >= 0; i--)
149. output += encoding.charAt(remainders[i]);
150. return output;
151. }
152. /*
153. * Encode a string as utf-8.
154. * For efficiency, this assumes the input is valid utf-16.
155. */
156. function str2rstr_utf8(input)
157. {
158. var output = "";
159. var i = -1;
160. var x, y;
161. while(++i < input.length)
162. {
163. /* Decode utf-16 surrogate pairs */
164. x = input.charCodeAt(i);
165. y = i + 1 < input.length ? input.charCodeAt(i + 1) : 0;
166. if(0xD800 <= x && x <= 0xDBFF && 0xDC00 <= y && y <= 0xDFFF)
167. {
168. x = 0x10000 + ((x & 0x03FF) << 10) + (y & 0x03FF);
169. i++;
170. }
171. /* Encode output as utf-8 */
172. if(x <= 0x7F)
173. output += String.fromCharCode(x);
174. else if(x <= 0x7FF)
175. output += String.fromCharCode(0xC0 | ((x >>> 6 ) & 0x1F),
176. 0x80 | ( x & 0x3F));
177. else if(x <= 0xFFFF)
178. output += String.fromCharCode(0xE0 | ((x >>> 12) & 0x0F),
179. 0x80 | ((x >>> 6 ) & 0x3F),
180. 0x80 | ( x & 0x3F));
181. else if(x <= 0x1FFFFF)
182. output += String.fromCharCode(0xF0 | ((x >>> 18) & 0x07),
183. 0x80 | ((x >>> 12) & 0x3F),
184. 0x80 | ((x >>> 6 ) & 0x3F),
185. 0x80 | ( x & 0x3F));
186. }
187. return output;
188. }
189. /*
190. * Encode a string as utf-16
191. */
192. function str2rstr_utf16le(input)
193. {
194. var output = "";
195. for(var i = 0; i < input.length; i++)
196. output += String.fromCharCode( input.charCodeAt(i) & 0xFF,
197. (input.charCodeAt(i) >>> 8) & 0xFF);
198. return output;
199. }
200. function str2rstr_utf16be(input)
201. {
202. var output = "";
203. for(var i = 0; i < input.length; i++)
204. output += String.fromCharCode((input.charCodeAt(i) >>> 8) & 0xFF,
205. input.charCodeAt(i) & 0xFF);
206. return output;
207. }
208. /*
209. * Convert a raw string to an array of little-endian words
210. * Characters >255 have their high-byte silently ignored.
211. */
212. function rstr2binl(input)
213. {
214. var output = Array(input.length >> 2);
215. for(var i = 0; i < output.length; i++)
216. output[i] = 0;
217. for(var i = 0; i < input.length * 8; i += 8)
218. output[i>>5] |= (input.charCodeAt(i / 8) & 0xFF) << (i%32);
219. return output;
220. }
221. /*
222. * Convert an array of little-endian words to a string
223. */
224. function binl2rstr(input)
225. {
226. var output = "";
227. for(var i = 0; i < input.length * 32; i += 8)
228. output += String.fromCharCode((input[i>>5] >>> (i % 32)) & 0xFF);
229. return output;
230. }
231. /*
232. * Calculate the MD5 of an array of little-endian words, and a bit length.
233. */
234. function binl_md5(x, len)
235. {
236. /* append padding */
237. x[len >> 5] |= 0x80 << ((len) % 32);
238. x[(((len + 64) >>> 9) << 4) + 14] = len;
239. var a = 1732584193;
240. var b = -271733879;
241. var c = -1732584194;
242. var d = 271733878;
243. for(var i = 0; i < x.length; i += 16)
244. {
245. var olda = a;
246. var oldb = b;
247. var oldc = c;
248. var oldd = d;
249. a = md5_ff(a, b, c, d, x[i+ 0], 7 , -680876936);
250. d = md5_ff(d, a, b, c, x[i+ 1], 12, -389564586);
251. c = md5_ff(c, d, a, b, x[i+ 2], 17, 606105819);
252. b = md5_ff(b, c, d, a, x[i+ 3], 22, -1044525330);
253. a = md5_ff(a, b, c, d, x[i+ 4], 7 , -176418897);
254. d = md5_ff(d, a, b, c, x[i+ 5], 12, 1200080426);
255. c = md5_ff(c, d, a, b, x[i+ 6], 17, -1473231341);
256. b = md5_ff(b, c, d, a, x[i+ 7], 22, -45705983);
257. a = md5_ff(a, b, c, d, x[i+ 8], 7 , 1770035416);
258. d = md5_ff(d, a, b, c, x[i+ 9], 12, -1958414417);
259. c = md5_ff(c, d, a, b, x[i+10], 17, -42063);
260. b = md5_ff(b, c, d, a, x[i+11], 22, -1990404162);
261. a = md5_ff(a, b, c, d, x[i+12], 7 , 1804603682);
262. d = md5_ff(d, a, b, c, x[i+13], 12, -40341101);
263. c = md5_ff(c, d, a, b, x[i+14], 17, -1502002290);
264. b = md5_ff(b, c, d, a, x[i+15], 22, 1236535329);
265. a = md5_gg(a, b, c, d, x[i+ 1], 5 , -165796510);
266. d = md5_gg(d, a, b, c, x[i+ 6], 9 , -1069501632);
267. c = md5_gg(c, d, a, b, x[i+11], 14, 643717713);
268. b = md5_gg(b, c, d, a, x[i+ 0], 20, -373897302);
269. a = md5_gg(a, b, c, d, x[i+ 5], 5 , -701558691);
270. d = md5_gg(d, a, b, c, x[i+10], 9 , 38016083);
271. c = md5_gg(c, d, a, b, x[i+15], 14, -660478335);
272. b = md5_gg(b, c, d, a, x[i+ 4], 20, -405537848);
273. a = md5_gg(a, b, c, d, x[i+ 9], 5 , 568446438);
274. d = md5_gg(d, a, b, c, x[i+14], 9 , -1019803690);
275. c = md5_gg(c, d, a, b, x[i+ 3], 14, -187363961);
276. b = md5_gg(b, c, d, a, x[i+ 8], 20, 1163531501);
277. a = md5_gg(a, b, c, d, x[i+13], 5 , -1444681467);
278. d = md5_gg(d, a, b, c, x[i+ 2], 9 , -51403784);
279. c = md5_gg(c, d, a, b, x[i+ 7], 14, 1735328473);
280. b = md5_gg(b, c, d, a, x[i+12], 20, -1926607734);
281. a = md5_hh(a, b, c, d, x[i+ 5], 4 , -378558);
282. d = md5_hh(d, a, b, c, x[i+ 8], 11, -2022574463);
283. c = md5_hh(c, d, a, b, x[i+11], 16, 1839030562);
284. b = md5_hh(b, c, d, a, x[i+14], 23, -35309556);
285. a = md5_hh(a, b, c, d, x[i+ 1], 4 , -1530992060);
286. d = md5_hh(d, a, b, c, x[i+ 4], 11, 1272893353);
287. c = md5_hh(c, d, a, b, x[i+ 7], 16, -155497632);
288. b = md5_hh(b, c, d, a, x[i+10], 23, -1094730640);
289. a = md5_hh(a, b, c, d, x[i+13], 4 , 681279174);
290. d = md5_hh(d, a, b, c, x[i+ 0], 11, -358537222);
291. c = md5_hh(c, d, a, b, x[i+ 3], 16, -722521979);
292. b = md5_hh(b, c, d, a, x[i+ 6], 23, 76029189);
293. a = md5_hh(a, b, c, d, x[i+ 9], 4 , -640364487);
294. d = md5_hh(d, a, b, c, x[i+12], 11, -421815835);
295. c = md5_hh(c, d, a, b, x[i+15], 16, 530742520);
296. b = md5_hh(b, c, d, a, x[i+ 2], 23, -995338651);
297. a = md5_ii(a, b, c, d, x[i+ 0], 6 , -198630844);
298. d = md5_ii(d, a, b, c, x[i+ 7], 10, 1126891415);
299. c = md5_ii(c, d, a, b, x[i+14], 15, -1416354905);
300. b = md5_ii(b, c, d, a, x[i+ 5], 21, -57434055);
301. a = md5_ii(a, b, c, d, x[i+12], 6 , 1700485571);
302. d = md5_ii(d, a, b, c, x[i+ 3], 10, -1894986606);
303. c = md5_ii(c, d, a, b, x[i+10], 15, -1051523);
304. b = md5_ii(b, c, d, a, x[i+ 1], 21, -2054922799);
305. a = md5_ii(a, b, c, d, x[i+ 8], 6 , 1873313359);
306. d = md5_ii(d, a, b, c, x[i+15], 10, -30611744);
307. c = md5_ii(c, d, a, b, x[i+ 6], 15, -1560198380);
308. b = md5_ii(b, c, d, a, x[i+13], 21, 1309151649);
309. a = md5_ii(a, b, c, d, x[i+ 4], 6 , -145523070);
310. d = md5_ii(d, a, b, c, x[i+11], 10, -1120210379);
311. c = md5_ii(c, d, a, b, x[i+ 2], 15, 718787259);
312. b = md5_ii(b, c, d, a, x[i+ 9], 21, -343485551);
313. a = safe_add(a, olda);
314. b = safe_add(b, oldb);
315. c = safe_add(c, oldc);
316. d = safe_add(d, oldd);
317. }
318. return Array(a, b, c, d);
319. }
320. /*
321. * These functions implement the four basic operations the algorithm uses.
322. */
323. function md5_cmn(q, a, b, x, s, t)
324. {
325. return safe_add(bit_rol(safe_add(safe_add(a, q), safe_add(x, t)), s),b);
326. }
327. function md5_ff(a, b, c, d, x, s, t)
328. {
329. return md5_cmn((b & c) | ((~b) & d), a, b, x, s, t);
330. }
331. function md5_gg(a, b, c, d, x, s, t)
332. {
333. return md5_cmn((b & d) | (c & (~d)), a, b, x, s, t);
334. }
335. function md5_hh(a, b, c, d, x, s, t)
336. {
337. return md5_cmn(b ^ c ^ d, a, b, x, s, t);
338. }
339. function md5_ii(a, b, c, d, x, s, t)
340. {
341. return md5_cmn(c ^ (b | (~d)), a, b, x, s, t);
342. }
343. /*
344. * Add integers, wrapping at 2^32. This uses 16-bit operations internally
345. * to work around bugs in some JS interpreters.
346. */
347. function safe_add(x, y)
348. {
349. var lsw = (x & 0xFFFF) + (y & 0xFFFF);
350. var msw = (x >> 16) + (y >> 16) + (lsw >> 16);
351. return (msw << 16) | (lsw & 0xFFFF);
352. }
353. /*
354. * Bitwise rotate a 32-bit number to the left.
355. */
356. function bit_rol(num, cnt)
357. {
358. return (num << cnt) | (num >>> (32 - cnt));
359. }

js base64,代码如下:

1. (function(global) {
2. 'use strict';
3. // existing version for noConflict()
4. var _Base64 = global.Base64;
5. var version = "2.1.4";
6. // if node.js, we use Buffer
7. var buffer;
8. if (typeof module !== 'undefined' && module.exports) {
9. buffer = require('buffer').Buffer;
10. }
11. // constants
12. var b64chars
13. = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/';
14. var b64tab = function(bin) {
15. var t = {};
16. for (var i = 0, l = bin.length; i < l; i++) t[bin.charAt(i)] = i;
17. return t;
18. }(b64chars);
19. var fromCharCode = String.fromCharCode;
20. // encoder stuff
21. var cb_utob = function(c) {
22. if (c.length < 2) {
23. var cc = c.charCodeAt(0);
24. return cc < 0x80 ? c
25. : cc < 0x800 ? (fromCharCode(0xc0 | (cc >>> 6))
26. + fromCharCode(0x80 | (cc & 0x3f)))
27. : (fromCharCode(0xe0 | ((cc >>> 12) & 0x0f))
28. + fromCharCode(0x80 | ((cc >>> 6) & 0x3f))
29. + fromCharCode(0x80 | ( cc & 0x3f)));
30. } else {
31. var cc = 0x10000
32. + (c.charCodeAt(0) - 0xD800) * 0x400
33. + (c.charCodeAt(1) - 0xDC00);
34. return (fromCharCode(0xf0 | ((cc >>> 18) & 0x07))
35. + fromCharCode(0x80 | ((cc >>> 12) & 0x3f))
36. + fromCharCode(0x80 | ((cc >>> 6) & 0x3f))
37. + fromCharCode(0x80 | ( cc & 0x3f)));
38. }
39. };
40. var re_utob = /[uD800-uDBFF][uDC00-uDFFFF]|[^x00-x7F]/g;
41. var utob = function(u) {
42. return u.replace(re_utob, cb_utob);
43. };
44. var cb_encode = function(ccc) {
45. var padlen = [0, 2, 1][ccc.length % 3],
46. ord = ccc.charCodeAt(0) << 16
47. | ((ccc.length > 1 ? ccc.charCodeAt(1) : 0) << 8)
48. | ((ccc.length > 2 ? ccc.charCodeAt(2) : 0)),
49. chars = [
50. b64chars.charAt( ord >>> 18),
51. b64chars.charAt((ord >>> 12) & 63),
52. padlen >= 2 ? '=' : b64chars.charAt((ord >>> 6) & 63),
53. padlen >= 1 ? '=' : b64chars.charAt(ord & 63)
54. ];
55. return chars.join('');
56. };
57. var btoa = global.btoa ? function(b) {
58. return global.btoa(b);
59. } : function(b) {
60. return b.replace(/[sS]{1,3}/g, cb_encode);
61. };
62. var _encode = buffer
63. ? function (u) {
64. return (new buffer(u)).toString('base64')
65. }
66. : function (u) {
67. return btoa(utob(u))
68. }
69. ;
70. var encode = function(u, urisafe) {
71. return !urisafe
72. ? _encode(u)
73. : _encode(u).replace(/[+/]/g, function(m0) {
74. return m0 == '+' ? '-' : '_';
75. }).replace(/=/g, '');
76. };
77. var encodeURI = function(u) {
78. return encode(u, true)
79. };
80. // decoder stuff
81. var re_btou = new RegExp([
82. '[xC0-xDF][x80-xBF]',
83. '[xE0-xEF][x80-xBF]{2}',
84. '[xF0-xF7][x80-xBF]{3}'
85. ].join('|'), 'g');
86. var cb_btou = function(cccc) {
87. switch(cccc.length) {
88. case 4:
89. var cp = ((0x07 & cccc.charCodeAt(0)) << 18)
90. | ((0x3f & cccc.charCodeAt(1)) << 12)
91. | ((0x3f & cccc.charCodeAt(2)) << 6)
92. | (0x3f & cccc.charCodeAt(3)),
93. offset = cp - 0x10000;
94. return (fromCharCode((offset >>> 10) + 0xD800)
95. + fromCharCode((offset & 0x3FF) + 0xDC00));
96. case 3:
97. return fromCharCode(
98. ((0x0f & cccc.charCodeAt(0)) << 12)
99. | ((0x3f & cccc.charCodeAt(1)) << 6)
100. | (0x3f & cccc.charCodeAt(2))
101. );
102. default:
103. return fromCharCode(
104. ((0x1f & cccc.charCodeAt(0)) << 6)
105. | (0x3f & cccc.charCodeAt(1))
106. );
107. }
108. };
109. var btou = function(b) {
110. return b.replace(re_btou, cb_btou);
111. };
112. var cb_decode = function(cccc) {
113. var len = cccc.length,
114. padlen = len % 4,
115. n = (len > 0 ? b64tab[cccc.charAt(0)] << 18 : 0)
116. | (len > 1 ? b64tab[cccc.charAt(1)] << 12 : 0)
117. | (len > 2 ? b64tab[cccc.charAt(2)] << 6 : 0)
118. | (len > 3 ? b64tab[cccc.charAt(3)] : 0),
119. chars = [
120. fromCharCode( n >>> 16),
121. fromCharCode((n >>> 8) & 0xff),
122. fromCharCode( n & 0xff)
123. ];
124. chars.length -= [0, 0, 2, 1][padlen];
125. return chars.join('');
126. };
127. var atob = global.atob ? function(a) {
128. return global.atob(a);
129. } : function(a){
130. return a.replace(/[sS]{1,4}/g, cb_decode);
131. };
132. var _decode = buffer
133. ? function(a) {
134. return (new buffer(a, 'base64')).toString()
135. }
136. : function(a) {
137. return btou(atob(a))
138. };
139. var decode = function(a){
140. return _decode(
141. a.replace(/[-_]/g, function(m0) {
142. return m0 == '-' ? '+' : '/'
143. })
144. .replace(/[^A-Za-z0-9+/]/g, '')
145. );
146. };
147. var noConflict = function() {
148. var Base64 = global.Base64;
149. global.Base64 = _Base64;
150. return Base64;
151. };
152. // export Base64
153. global.Base64 = {
154. VERSION: version,
155. atob: atob,
156. btoa: btoa,
157. fromBase64: decode,
158. toBase64: encode,
159. utob: utob,
160. encode: encode,
161. encodeURI: encodeURI,
162. btou: btou,
163. decode: decode,
164. noConflict: noConflict
165. };
166. // if ES5 is available, make Base64.extendString() available
167. if (typeof Object.defineProperty === 'function') {
168. var noEnum = function(v){
169. return {
170. value:v,
171. enumerable:false,
172. writable:true,
173. configurable:true
174. };
175. };
176. global.Base64.extendString = function () {
177. Object.defineProperty(
178. String.prototype, 'fromBase64', noEnum(function () {
179. return decode(this)
180. }));
181. Object.defineProperty(
182. String.prototype, 'toBase64', noEnum(function (urisafe) {
183. return encode(this, urisafe)
184. }));
185. Object.defineProperty(
186. String.prototype, 'toBase64URI', noEnum(function () {
187. return encode(this, true)
188. }));
189. };
190. }
191. // that's it!
192. })(this);

最后把下面的很长的js分别保存为base64.js文件与md5.js文件,然后在要解密的文件中加载这两个js即可.