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。
复制代码 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);
            b = a;
            a = t;
        }
        a = safe_add(a, olda);
        b = safe_add(b, oldb);
        c = safe_add(c, oldc);
        d = safe_add(d, oldd);
        e = safe_add(e, olde);
    }
    return new Array(a, b, c, d, e);
}
/*
 *
 * Perform the appropriate triplet combination function for the current
 * iteration
 *
 * 返回对应F函数的值
 *
 */
function sha1_ft(t, b, c, d){
    if (t < 20)
        return (b & c) | ((~ b) & d);
    if (t < 40)
        return b ^ c ^ d;
    if (t < 60)
        return (b & c) | (b & d) | (c & d);
    return b ^ c ^ d; // t<80
}
/*
 *
 * Determine the appropriate additive constant for the current iteration
 *
 * 返回对应的Kt值
 *
 */
function sha1_kt(t){
    return (t < 20) "0123456789ABCDEF" : "0123456789abcdef";
    var str = "";
    for (var i = 0; i < binarray.length * 4; i++) {
        str += hex_tab.charAt((binarray[i 2] ((3 - i % 4) * 8 + 4)) & 0xF) +
        hex_tab.charAt((binarray[i 2] ((3 - i % 4) * 8)) & 0xF);
    }
    return str;
}
/*
 *
 * calculate MessageDigest accord to source message that inputted
 *
 */
function calcDigest(){
    var digestM = hex_sha1(document.SHAForm.SourceMessage.value);
    document.SHAForm.MessageDigest.value = digestM;
}

希望本文所述对大家的javascript程序设计有所帮助。