sha1 javascript

sha1 单向hash运算

/*
 * A JavaScript implementation of the Secure Hash Algorithm, SHA-1, as defined
 * in FIPS PUB 180-1 Version 2.1a Copyright Paul Johnston 2000 - 2002. Other
 * contributors: Greg Holt, Andrew Kepert, Ydnar, Lostinet Distributed under the
 * BSD License See http://pajhome.org.uk/crypt/md5 for details. 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_sha1(s) {
	return binb2hex(core_sha1(str2binb(s), s.length * chrsz));
}
function b64_sha1(s) {
	return binb2b64(core_sha1(str2binb(s), s.length * chrsz));
}
function str_sha1(s) {
	return binb2str(core_sha1(str2binb(s), s.length * chrsz));
}
function hex_hmac_sha1(key, data) {
	return binb2hex(core_hmac_sha1(key, data));
}
function b64_hmac_sha1(key, data) {
	return binb2b64(core_hmac_sha1(key, data));
}
function str_hmac_sha1(key, data) {
	return binb2str(core_hmac_sha1(key, data));
}

/*
 * 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(x, len) {
	/* append padding */
	x[len >> 5] |= 0x80 << (24 - len % 32);
	x[((len + 64 >> 9) << 4) + 15] = len;

	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) {
		var olda = a;
		var oldb = b;
		var oldc = c;
		var oldd = d;
		var olde = e;

		for ( var j = 0; j < 80; j++) {
			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 Array(a, b, c, d, e);

}

/*
 * Perform the appropriate triplet combination function for the current
 * iteration
 */
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;
}

/*
 * Determine the appropriate additive constant for the current iteration
 */
function sha1_kt(t) {
	return (t < 20) ? 1518500249 : (t < 40) ? 1859775393
			: (t < 60) ? -1894007588 : -899497514;
}

/*
 * Calculate the HMAC-SHA1 of a key and some data
 */
function core_hmac_sha1(key, data) {
	var bkey = str2binb(key);
	if (bkey.length > 16)
		bkey = core_sha1(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_sha1(ipad.concat(str2binb(data)), 512 + data.length * chrsz);
	return core_sha1(opad.concat(hash), 512 + 160);
}

/*
 * 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 rol(num, cnt) {
	return (num << cnt) | (num >>> (32 - cnt));
}

/*
 * Convert an 8-bit or 16-bit string to an array of big-endian words In 8-bit
 * function, characters >255 have their hi-byte silently ignored.
 */
function str2binb(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) << (32 - chrsz - i % 32);
	return bin;
}

/*
 * Convert an array of big-endian words to a string
 */
function binb2str(bin) {
	var str = "";
	var mask = (1 << chrsz) - 1;
	for ( var i = 0; i < bin.length * 32; i += chrsz)
		str += String.fromCharCode((bin[i >> 5] >>> (32 - chrsz - i % 32))
				& mask);
	return str;
}

/*
 * Convert an array of big-endian words to a hex string.
 */
function binb2hex(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] >> ((3 - i % 4) * 8 + 4)) & 0xF)
				+ hex_tab.charAt((binarray[i >> 2] >> ((3 - i % 4) * 8)) & 0xF);
	}
	return str;
}

/*
 * Convert an array of big-endian words to a base-64 string
 */
function binb2b64(binarray) {
	var tab = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
	var str = "";
	for ( var i = 0; i < binarray.length * 4; i += 3) {
		var triplet = (((binarray[i >> 2] >> 8 * (3 - i % 4)) & 0xFF) << 16)
				| (((binarray[i + 1 >> 2] >> 8 * (3 - (i + 1) % 4)) & 0xFF) << 8)
				| ((binarray[i + 2 >> 2] >> 8 * (3 - (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;
}


////////////////// test /////////////////////
function test() {
    var sha = hex_sha1("abc");
    var value = 'a9993e364706816aba3e25717850c26c9cd0d89d';
    alert('sha("abc")= ' + sha + '  验证：' + (sha == value));
}