这篇文章主要介绍了 JavaScript 实现的 SHA-1 加密算法, 以完整实例形式分析了 SHA-1 加密算法的具体实现技巧, 需要的朋友可以参考下
Javascript 是一种由 Netscape 的 LiveScript 发展而来的原型化继承的基于对象的动态类型的区分大小写的客户端脚本语言,主要目的是为了解决服务器端语言,比如 Perl,遗留的速度问题,为客户提供更流畅的浏览效果。
本文实例讲述了 JavaScript 实现的 SHA-1 加密算法。分享给大家供大家参考,具体如下:
- /**
- *
- * Secure Hash Algorithm (SHA1)
- * http://www.webtoolkit.info/
- *
- **/
- function SHA1 (msg) {
- function rotate_left(n,s) {
- var t4 = ( n<<s ) | (n>>>(32-s));
- return t4;
- };
- function lsb_hex(val) {
- var str="";
- var i;
- var vh;
- var vl;
- for( i=0; i<=6; i+=2 ) {
- vh = (val>>>(i*4+4))&0x0f;
- vl = (val>>>(i*4))&0x0f;
- str += vh.toString(16) + vl.toString(16);
- }
- return str;
- };
- function cvt_hex(val) {
- var str="";
- var i;
- var v;
- for( i=7; i>=0; i-- ) {
- v = (val>>>(i*4))&0x0f;
- str += v.toString(16);
- }
- return str;
- };
- function 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;
- };
- var blockstart;
- var i, j;
- var W = new Array(80);
- var H0 = 0x67452301;
- var H1 = 0xEFCDAB89;
- var H2 = 0x98BADCFE;
- var H3 = 0x10325476;
- var H4 = 0xC3D2E1F0;
- var A, B, C, D, E;
- var temp;
- msg = Utf8Encode(msg);
- var msg_len = msg.length;
- var word_array = new Array();
- for( i=0; i<msg_len-3; i+=4 ) {
- j = msg.charCodeAt(i)<<24 | msg.charCodeAt(i+1)<<16 |
- msg.charCodeAt(i+2)<<8 | msg.charCodeAt(i+3);
- word_array.push( j );
- }
- switch( msg_len % 4 ) {
- case 0:
- i = 0x080000000;
- break;
- case 1:
- i = msg.charCodeAt(msg_len-1)<<24 | 0x0800000;
- break;
- case 2:
- i = msg.charCodeAt(msg_len-2)<<24 | msg.charCodeAt(msg_len-1)<<16 | 0x08000;
- break;
- case 3:
- i = msg.charCodeAt(msg_len-3)<<24 | msg.charCodeAt(msg_len-2)<<16 | msg.charCodeAt(msg_len-1)<<8 | 0x80;
- break;
- }
- word_array.push( i );
- while( (word_array.length % 16) != 14 ) word_array.push( 0 );
- word_array.push( msg_len>>>29 );
- word_array.push( (msg_len<<3)&0x0ffffffff );
- for ( blockstart=0; blockstart<word_array.length; blockstart+=16 ) {
- for( i=0; i<16; i++ ) W[i] = word_array[blockstart+i];
- for( i=16; i<=79; i++ ) W[i] = rotate_left(W[i-3] ^ W[i-8] ^ W[i-14] ^ W[i-16], 1);
- A = H0;
- B = H1;
- C = H2;
- D = H3;
- E = H4;
- for( i= 0; i<=19; i++ ) {
- temp = (rotate_left(A,5) + ((B&C) | (~B&D)) + E + W[i] + 0x5A827999) & 0x0ffffffff;
- E = D;
- D = C;
- C = rotate_left(B,30);
- B = A;
- A = temp;
- }
- for( i=20; i<=39; i++ ) {
- temp = (rotate_left(A,5) + (B ^ C ^ D) + E + W[i] + 0x6ED9EBA1) & 0x0ffffffff;
- E = D;
- D = C;
- C = rotate_left(B,30);
- B = A;
- A = temp;
- }
- for( i=40; i<=59; i++ ) {
- temp = (rotate_left(A,5) + ((B&C) | (B&D) | (C&D)) + E + W[i] + 0x8F1BBCDC) & 0x0ffffffff;
- E = D;
- D = C;
- C = rotate_left(B,30);
- B = A;
- A = temp;
- }
- for( i=60; i<=79; i++ ) {
- temp = (rotate_left(A,5) + (B ^ C ^ D) + E + W[i] + 0xCA62C1D6) & 0x0ffffffff;
- E = D;
- D = C;
- C = rotate_left(B,30);
- B = A;
- A = temp;
- }
- H0 = (H0 + A) & 0x0ffffffff;
- H1 = (H1 + B) & 0x0ffffffff;
- H2 = (H2 + C) & 0x0ffffffff;
- H3 = (H3 + D) & 0x0ffffffff;
- H4 = (H4 + E) & 0x0ffffffff;
- }
- var temp = cvt_hex(H0) + cvt_hex(H1) + cvt_hex(H2) + cvt_hex(H3) + cvt_hex(H4);
- return temp.toLowerCase();
- }
希望本文所述对大家 JavaScript 程序设计有所帮助。
来源: http://www.phperz.com/article/17/0216/267243.html