The SHA (Secure Hash Algorithm) is one of the many cryptographic hash functions. It is suggested that SHA256 or greater must used for critical technology.
This script is used to process variable length message into a fixed-length output using the SHA256 algorithm.
Source code for webtoolkit.sha256.as
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
|
/**
*
* Secure Hash Algorithm (SHA256)
* http://www.webtoolkit.info/
*
**/
function SHA256(s){
var chrsz = 8;
var hexcase = 0;
function safe_add (x, y) {
var lsw = (x & 0xFFFF) + (y & 0xFFFF);
var msw = (x >> 16) + (y >> 16) + (lsw >> 16);
return (msw << 16) | (lsw & 0xFFFF);
}
function S (X, n) { return ( X >>> n ) | (X << (32 - n)); }
function R (X, n) { return ( X >>> n ); }
function Ch(x, y, z) { return ((x & y) ^ ((~x) & z)); }
function Maj(x, y, z) { return ((x & y) ^ (x & z) ^ (y & z)); }
function Sigma0256(x) { return (S(x, 2) ^ S(x, 13) ^ S(x, 22)); }
function Sigma1256(x) { return (S(x, 6) ^ S(x, 11) ^ S(x, 25)); }
function Gamma0256(x) { return (S(x, 7) ^ S(x, 18) ^ R(x, 3)); }
function Gamma1256(x) { return (S(x, 17) ^ S(x, 19) ^ R(x, 10)); }
function core_sha256 (m, l) {
var K = new Array(0x428A2F98, 0x71374491, 0xB5C0FBCF, 0xE9B5DBA5, 0x3956C25B, 0x59F111F1, 0x923F82A4, 0xAB1C5ED5, 0xD807AA98, 0x12835B01, 0x243185BE, 0x550C7DC3, 0x72BE5D74, 0x80DEB1FE, 0x9BDC06A7, 0xC19BF174, 0xE49B69C1, 0xEFBE4786, 0xFC19DC6, 0x240CA1CC, 0x2DE92C6F, 0x4A7484AA, 0x5CB0A9DC, 0x76F988DA, 0x983E5152, 0xA831C66D, 0xB00327C8, 0xBF597FC7, 0xC6E00BF3, 0xD5A79147, 0x6CA6351, 0x14292967, 0x27B70A85, 0x2E1B2138, 0x4D2C6DFC, 0x53380D13, 0x650A7354, 0x766A0ABB, 0x81C2C92E, 0x92722C85, 0xA2BFE8A1, 0xA81A664B, 0xC24B8B70, 0xC76C51A3, 0xD192E819, 0xD6990624, 0xF40E3585, 0x106AA070, 0x19A4C116, 0x1E376C08, 0x2748774C, 0x34B0BCB5, 0x391C0CB3, 0x4ED8AA4A, 0x5B9CCA4F, 0x682E6FF3, 0x748F82EE, 0x78A5636F, 0x84C87814, 0x8CC70208, 0x90BEFFFA, 0xA4506CEB, 0xBEF9A3F7, 0xC67178F2);
var HASH = new Array(0x6A09E667, 0xBB67AE85, 0x3C6EF372, 0xA54FF53A, 0x510E527F, 0x9B05688C, 0x1F83D9AB, 0x5BE0CD19);
var W = new Array(64);
var a, b, c, d, e, f, g, h, i, j;
var T1, T2;
m[l >> 5] |= 0x80 << (24 - l % 32);
m[((l + 64 >> 9) << 4) + 15] = l;
for ( var i = 0; i<m.length; i+=16 ) {
a = HASH[0];
b = HASH[1];
c = HASH[2];
d = HASH[3];
e = HASH[4];
f = HASH[5];
g = HASH[6];
h = HASH[7];
for ( var j = 0; j<64; j++) {
if (j < 16) W[j] = m[j + i];
else W[j] = safe_add(safe_add(safe_add(Gamma1256(W[j - 2]), W[j - 7]), Gamma0256(W[j - 15])), W[j - 16]);
T1 = safe_add(safe_add(safe_add(safe_add(h, Sigma1256(e)), Ch(e, f, g)), K[j]), W[j]);
T2 = safe_add(Sigma0256(a), Maj(a, b, c));
h = g;
g = f;
f = e;
e = safe_add(d, T1);
d = c;
c = b;
b = a;
a = safe_add(T1, T2);
}
HASH[0] = safe_add(a, HASH[0]);
HASH[1] = safe_add(b, HASH[1]);
HASH[2] = safe_add(c, HASH[2]);
HASH[3] = safe_add(d, HASH[3]);
HASH[4] = safe_add(e, HASH[4]);
HASH[5] = safe_add(f, HASH[5]);
HASH[6] = safe_add(g, HASH[6]);
HASH[7] = safe_add(h, HASH[7]);
}
return HASH;
}
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) << (24 - i%32);
}
return bin;
}
function Utf8Encode(string) {
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;
}
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;
}
s = Utf8Encode(s);
return binb2hex(core_sha256(str2binb(s), s.length * chrsz));
}
|