问题: 上传图片含有大量重复

解决思路.获取图片MD5值 传到后台进行比较

一、引入spark-md5.js

var sMD5 = require('../../../utils/spark-md5.js')

二、选择图片获取文件

三、spark-md5.js

参考： https://blog.csdn.net/aaron9185/article/details/84855014

2、在小程序模块中使用require引入外部模块；也可以在index.html中直接全局引入md5.js文件。

因为源md5.js中没有队模块因为输出，如果使用require需要export，所以在md5.js中需要加入以下代码：

module.exports = {

hexMD5: hex_md5, //需要输出的加密算法，我这边只写了我需要得两种

b64Md5: b64_md5,

}

在js文件中使用require引入md5:

const md5 = require('../../assets/js/md5/md5.js')

使用：

let b64 = md5.b64Md5(code)//code需要加密的数据

下面是我的文件结构：

md5.js 代码如下

/*

* A JavaScript implementation of the RSA Data Security, Inc. MD5 Message

* Digest Algorithm, as defined in RFC 1321.

* Version 2.1 Copyright (C) Paul Johnston 1999 - 2002.

* Other contributors: Greg Holt, Andrew Kepert, Ydnar, Lostinet

* Distributed under the BSD License

* See http://pajhome.org.uk/crypt/md5 for more info.

*/

/*

* Configurable variables. You may need to tweak these to be compatible with

* the server-side, but the defaults work in most cases.

*/

var hexcase =

0

/* hex output format. 0 - lowercase1 - uppercase */

var b64pad =

""

/* base-64 pad character. "=" for strict RFC compliance */

var chrsz =

8

/* bits per input character. 8 - ASCII16 - Unicode */

/*

* These are the functions you'll usually want to call

* They take string arguments and return either hex or base-64 encoded strings

*/

function hex_md5(s){

return binl2hex(core_md5(str2binl(s), s.length * chrsz))}

function b64_md5(s){

return binl2b64(core_md5(str2binl(s), s.length * chrsz))}

function str_md5(s){

return binl2str(core_md5(str2binl(s), s.length * chrsz))}

function hex_hmac_md5(key, data) {

return binl2hex(core_hmac_md5(key, data))}

function b64_hmac_md5(key, data) {

return binl2b64(core_hmac_md5(key, data))}

function str_hmac_md5(key, data) {

return binl2str(core_hmac_md5(key, data))}

/*

* Perform a simple self-test to see if the VM is working

*/

function md5_vm_test()

{

return hex_md5( "abc") ==

"900150983cd24fb0d6963f7d28e17f72"

}

/*

* Calculate the MD5 of an array of little-endian words, and a bit length

*/

function core_md5(x, len)

{

/* append padding */

x[len >>

5] |=

0x80 <<((len) %

32)

x[(((len +

64) >>>

9) <<

4) +

14] = len

var a =

1732584193

var b = - 271733879

var c = - 1732584194

var d =

271733878

for( var i =

0i <x.lengthi +=

16)

{

var olda = a

var oldb = b

var oldc = c

var oldd = d

a = md5_ff(a, b, c, d, x[i+

0],

7 , - 680876936)

d = md5_ff(d, a, b, c, x[i+

1],

12, - 389564586)

c = md5_ff(c, d, a, b, x[i+

2],

17,

606105819)

b = md5_ff(b, c, d, a, x[i+

3],

22, - 1044525330)

a = md5_ff(a, b, c, d, x[i+

4],

7 , - 176418897)

d = md5_ff(d, a, b, c, x[i+

5],

12,

1200080426)

c = md5_ff(c, d, a, b, x[i+

6],

17, - 1473231341)

b = md5_ff(b, c, d, a, x[i+

7],

22, - 45705983)

a = md5_ff(a, b, c, d, x[i+

8],

7 ,

1770035416)

d = md5_ff(d, a, b, c, x[i+

9],

12, - 1958414417)

c = md5_ff(c, d, a, b, x[i+ 10],

17, - 42063)

b = md5_ff(b, c, d, a, x[i+ 11],

22, - 1990404162)

a = md5_ff(a, b, c, d, x[i+ 12],

7 ,

1804603682)

d = md5_ff(d, a, b, c, x[i+ 13],

12, - 40341101)

c = md5_ff(c, d, a, b, x[i+ 14],

17, - 1502002290)

b = md5_ff(b, c, d, a, x[i+ 15],

22,

1236535329)

a = md5_gg(a, b, c, d, x[i+

1],

5 , - 165796510)

d = md5_gg(d, a, b, c, x[i+

6],

9 , - 1069501632)

c = md5_gg(c, d, a, b, x[i+ 11],

14,

643717713)

b = md5_gg(b, c, d, a, x[i+

0],

20, - 373897302)

a = md5_gg(a, b, c, d, x[i+

5],

5 , - 701558691)

d = md5_gg(d, a, b, c, x[i+ 10],

9 ,

38016083)

c = md5_gg(c, d, a, b, x[i+ 15],

14, - 660478335)

b = md5_gg(b, c, d, a, x[i+

4],

20, - 405537848)

a = md5_gg(a, b, c, d, x[i+

9],

5 ,

568446438)

d = md5_gg(d, a, b, c, x[i+ 14],

9 , - 1019803690)

c = md5_gg(c, d, a, b, x[i+

3],

14, - 187363961)

b = md5_gg(b, c, d, a, x[i+

8],

20,

1163531501)

a = md5_gg(a, b, c, d, x[i+ 13],

5 , - 1444681467)

d = md5_gg(d, a, b, c, x[i+

2],

9 , - 51403784)

c = md5_gg(c, d, a, b, x[i+

7],

14,

1735328473)

b = md5_gg(b, c, d, a, x[i+ 12],

20, - 1926607734)

a = md5_hh(a, b, c, d, x[i+

5],

4 , - 378558)

d = md5_hh(d, a, b, c, x[i+

8],

11, - 2022574463)

c = md5_hh(c, d, a, b, x[i+ 11],

16,

1839030562)

b = md5_hh(b, c, d, a, x[i+ 14],

23, - 35309556)

a = md5_hh(a, b, c, d, x[i+

1],

4 , - 1530992060)

d = md5_hh(d, a, b, c, x[i+

4],

11,

1272893353)

c = md5_hh(c, d, a, b, x[i+

7],

16, - 155497632)

b = md5_hh(b, c, d, a, x[i+ 10],

23, - 1094730640)

a = md5_hh(a, b, c, d, x[i+ 13],

4 ,

681279174)

d = md5_hh(d, a, b, c, x[i+

0],

11, - 358537222)

c = md5_hh(c, d, a, b, x[i+

3],

16, - 722521979)

b = md5_hh(b, c, d, a, x[i+

6],

23,

76029189)

a = md5_hh(a, b, c, d, x[i+

9],

4 , - 640364487)

d = md5_hh(d, a, b, c, x[i+ 12],

11, - 421815835)

c = md5_hh(c, d, a, b, x[i+ 15],

16,

530742520)

b = md5_hh(b, c, d, a, x[i+

2],

23, - 995338651)

a = md5_ii(a, b, c, d, x[i+

0],

6 , - 198630844)

d = md5_ii(d, a, b, c, x[i+

7],

10,

1126891415)

c = md5_ii(c, d, a, b, x[i+ 14],

15, - 1416354905)

b = md5_ii(b, c, d, a, x[i+

5],

21, - 57434055)

a = md5_ii(a, b, c, d, x[i+ 12],

6 ,

1700485571)

d = md5_ii(d, a, b, c, x[i+

3],

10, - 1894986606)

c = md5_ii(c, d, a, b, x[i+ 10],

15, - 1051523)

b = md5_ii(b, c, d, a, x[i+

1],

21, - 2054922799)

a = md5_ii(a, b, c, d, x[i+

8],

6 ,

1873313359)

d = md5_ii(d, a, b, c, x[i+ 15],

10, - 30611744)

c = md5_ii(c, d, a, b, x[i+

6],

15, - 1560198380)

b = md5_ii(b, c, d, a, x[i+ 13],

21,

1309151649)

a = md5_ii(a, b, c, d, x[i+

4],

6 , - 145523070)

d = md5_ii(d, a, b, c, x[i+ 11],

10, - 1120210379)

c = md5_ii(c, d, a, b, x[i+

2],

15,

718787259)

b = md5_ii(b, c, d, a, x[i+

9],

21, - 343485551)

a = safe_add(a, olda)

b = safe_add(b, oldb)

c = safe_add(c, oldc)

d = safe_add(d, oldd)

}

return Array(a, b, c, d)

}

/*

* These functions implement the four basic operations the algorithm uses.

*/

function md5_cmn(q, a, b, x, s, t)

{

return safe_add(bit_rol(safe_add(safe_add(a, q), safe_add(x, t)), s),b)

}

function md5_ff(a, b, c, d, x, s, t)

{

return md5_cmn((b &c) | ((~b) &d), a, b, x, s, t)

}

function md5_gg(a, b, c, d, x, s, t)

{

return md5_cmn((b &d) | (c &(~d)), a, b, x, s, t)

}

function md5_hh(a, b, c, d, x, s, t)

{

return md5_cmn(b ^ c ^ d, a, b, x, s, t)

}

function md5_ii(a, b, c, d, x, s, t)

{

return md5_cmn(c ^ (b | (~d)), a, b, x, s, t)

}

/*

* Calculate the HMAC-MD5, of a key and some data

*/

function core_hmac_md5(key, data)

{

var bkey = str2binl(key)

if(bkey.length >

16) bkey = core_md5(bkey, key.length * chrsz)

var ipad = Array( 16), opad = Array( 16)

for( var i =

0i <

16i++)

{

ipad[i] = bkey[i] ^

0x36363636

opad[i] = bkey[i] ^

0x5C5C5C5C

}

var hash = core_md5(ipad.concat(str2binl(data)),

512 + data.length * chrsz)

return core_md5(opad.concat(hash),

512 +

128)

}

/*

* Add integers, wrapping at 2^32. This uses 16-bit operations internally

* to work around bugs in some JS interpreters.

*/

function safe_add(x, y)

{

var lsw = (x &

0xFFFF) + (y &

0xFFFF)

var msw = (x >>

16) + (y >>

16) + (lsw >>

16)

return (msw <<

16) | (lsw &

0xFFFF)

}

/*

* Bitwise rotate a 32-bit number to the left.

*/

function bit_rol(num, cnt)

{

return (num <<cnt) | (num >>>( 32 - cnt))

}

/*

* Convert a string to an array of little-endian words

* If chrsz is ASCII, characters >255 have their hi-byte silently ignored.

*/

function str2binl(str)

{

var bin = Array()

var mask = ( 1 <<chrsz) -

1

for( var i =

0i <str.length * chrszi += chrsz)

bin[i>> 5] |= (str.charCodeAt(i / chrsz) &mask) <<(i% 32)

return bin

}

/*

* Convert an array of little-endian words to a string

*/

function binl2str(bin)

{

var str =

""

var mask = ( 1 <<chrsz) -

1

for( var i =

0i <bin.length *

32i += chrsz)

str += String.fromCharCode((bin[i>> 5] >>>(i %

32)) &mask)

return str

}

/*

* Convert an array of little-endian words to a hex string.

*/

function binl2hex(binarray)

{

var hex_tab = hexcase ?

"0123456789ABCDEF" :

"0123456789abcdef"

var str =

""

for( var i =

0i <binarray.length *

4i++)

{

str += hex_tab.charAt((binarray[i>> 2] >>((i% 4)* 8+ 4)) &

0xF) +

hex_tab.charAt((binarray[i>> 2] >>((i% 4)* 8 )) &

0xF)

}

return str

}

/*

* Convert an array of little-endian words to a base-64 string

*/

function binl2b64(binarray)

{

var tab =

"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"

var str =

""

for( var i =

0i <binarray.length *

4i +=

3)

{

var triplet = (((binarray[i >>

2] >>

8 * ( i % 4)) &

0xFF) <<

16)

| (((binarray[i+ 1 >>

2] >>

8 * ((i+ 1)% 4)) &

0xFF) <<

8 )

| ((binarray[i+ 2 >>

2] >>

8 * ((i+ 2)% 4)) &

0xFF)

for( var j =

0j <

4j++)

{

if(i *

8 + j *

6 >binarray.length *

32) str += b64pad

else str += tab.charAt((triplet >>

6*( 3-j)) &

0x3F)

}

}

return str

}

module.exports = {

hexMD5: hex_md5,

b64Md5: b64_md5,

}

login.js是我们的业务js区域,首先我们这样引用md5.js

然后我们这样使用md5.js中的md5加密函数对字符进行加密

这样就可以对密码进行md5加密了