js中如何实现md5加密处理

我不是女神ヾ 2022-09-07 14:52 150阅读 0赞

### js中如何实现md5加密处理 ###

*   *  MD5加密优缺点
     *  md5.js源码如下
     *  常用加密算法

## MD5加密优缺点 ##

1，用js对私密信息加密可避免在网络中输入明文信息，被他人截取数据包而造成数据泄露。

2，避免缓存中自动缓存密码。比如在使用火狐浏览器登陆时，输入的用户名及密码自动缓存后，下次登陆无需输入密码就可实现登录，这样就给别人留下了漏洞，当别人使用你的电脑登陆那么你的密码就泄露了。使用js加密时，缓存的加密后的密文，用密文做密码登录是不成功的，即使泄露也是泄露的密文，对密码不会造成威胁。 缺点是： 每次登陆时都要手动输入密码，比较麻烦。

3，使用js加密，减少了服务器加密时的资源消耗，从理论上提高了服务器的性能。为了安全，很有必要在做服务端的加密，无论从理论还是实际，两道门比一道门要安全些，至少给攻击者造成了一个障碍。

## md5.js源码如下 ##

/* * 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 - lowercase; 1 - uppercase */
    var b64pad = ""; /* base-64 pad character. "=" for strict RFC compliance */
    var chrsz = 8;  /* bits per input character. 8 - ASCII; 16 - 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) { 
        s = md5_Utf8Encode(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));
    }
    
    //中文转换
    function md5_Utf8Encode(string) { 
        string = string.replace(/\r\n/g, "\n");
        var utftext = "";
        for (var n = 0; n < string.length; n++) { 
            var c = string.charCodeAt(n);
            if (c < 128) { 
                utftext += String.fromCharCode(c);
            } else if ((c > 127) && (c < 2048)) { 
                utftext += String.fromCharCode((c >> 6) | 192);
                utftext += String.fromCharCode((c & 63) | 128);
            } else { 
                utftext += String.fromCharCode((c >> 12) | 224);
                utftext += String.fromCharCode(((c >> 6) & 63) | 128);
                utftext += String.fromCharCode((c & 63) | 128);
            }
        }
        return utftext;
    };
    
    /* * 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 = 0; i < x.length; i += 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 = 0; i < 16; i++) { 
            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 = 0; i < str.length * chrsz; i += 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 = 0; i < bin.length * 32; i += 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 = 0; i < binarray.length * 4; i++) { 
            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 = 0; i < binarray.length * 4; i += 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 = 0; j < 4; j++) { 
                if (i * 8 + j * 6 > binarray.length * 32) str += b64pad;
                else str += tab.charAt((triplet >> 6 * (3 - j)) & 0x3F);
            }
        }
        return str;
    }

## 常用加密算法 ##