JavaScript实现SHA-1加密算法的方法

本文实例讲述了JavaScript实现SHA-1加密算法的方法。分享给大家供大家参考。具体实现方法如下：

调用方法：hex_sha1即可。
代码如下:/*
 *
 * A JavaScript implementation of the Secure Hash Algorithm, SHA-1, as defined
 * in FIPS PUB 180-1
 *
 * By lizq
 *
 * 2006-11-11
 *
 */
/*
 *
 * Configurable variables.
 *
 */
var hexcase = 0; /* hex output format. 0 - lowercase; 1 - uppercase */
var chrsz = 8; /* bits per input character. 8 - ASCII; 16 - Unicode */
/*
 *
 * The main function to calculate message digest
 *
 */
function hex_sha1(s){
    return binb2hex(core_sha1(AlignSHA1(s)));
}
/*
 *
 * Perform a simple self-test to see if the VM is working
 *
 */
function sha1_vm_test(){
    return hex_sha1("abc") == "a9993e364706816aba3e25717850c26c9cd0d89d";
}
/*
 *
 * Calculate the SHA-1 of an array of big-endian words, and a bit length
 *
 */
function core_sha1(blockArray){
    var x = blockArray; // append padding
    var w = Array(80);
    var a = 1732584193;
    var b = -271733879;
    var c = -1732584194;
    var d = 271733878;
    var e = -1009589776;
    for (var i = 0; i < x.length; i += 16) // 每次处理512位 16*32
    {
        var olda = a;
        var oldb = b;
        var oldc = c;
        var oldd = d;
        var olde = e;
        for (var j = 0; j < 80; j++) // 对每个512位进行80步操作
        {
            if (j < 16)
                w[j] = x[i + j];
            else
                w[j] = rol(w[j - 3] ^ w[j - 8] ^ w[j - 14] ^ w[j - 16], 1);
            var t = safe_add(safe_add(rol(a, 5), sha1_ft(j, b, c, d)), safe_add(safe_add(e, w[j]), sha1_kt(j)));
            e = d;
            d = c;
            c = rol(b, 30);