/*
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* A JavaScript implementation of the Secure Hash Algorithm, SHA-1, as defined
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* in FIPS PUB 180-1
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* Copyright (C) Paul Johnston 2000.
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* See http://pajhome.org.uk/site/legal.html for details.
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*/
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/*
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* Convert a 32-bit number to a hex string with ms-byte first
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*/
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var hex_chr = "0123456789abcdef";
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function hex(num)
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{
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var str = "";
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for(var j = 7; j >= 0; j--)
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str += hex_chr.charAt((num >> (j * 4)) & 0x0F);
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return str;
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}
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/*
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* Convert a string to a sequence of 16-word blocks, stored as an array.
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* Append padding bits and the length, as described in the SHA1 standard.
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*/
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function str2blks_SHA1(str)
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{
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var nblk = ((str.length + 8) >> 6) + 1;
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var blks = new Array(nblk * 16);
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for(var i = 0; i < nblk * 16; i++) blks[i] = 0;
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for(i = 0; i < str.length; i++)
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blks[i >> 2] |= str.charCodeAt(i) << (24 - (i % 4) * 8);
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blks[i >> 2] |= 0x80 << (24 - (i % 4) * 8);
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blks[nblk * 16 - 1] = str.length * 8;
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return blks;
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}
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/*
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* Add integers, wrapping at 2^32. This uses 16-bit operations internally
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* to work around bugs in some JS interpreters.
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*/
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function add(x, y)
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{
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var lsw = (x & 0xFFFF) + (y & 0xFFFF);
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var msw = (x >> 16) + (y >> 16) + (lsw >> 16);
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return (msw << 16) | (lsw & 0xFFFF);
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}
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/*
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* Bitwise rotate a 32-bit number to the left
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*/
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function rol(num, cnt)
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{
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return (num << cnt) | (num >>> (32 - cnt));
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}
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/*
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* Perform the appropriate triplet combination function for the current
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* iteration
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*/
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function ft(t, b, c, d)
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{
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if(t < 20) return (b & c) | ((~b) & d);
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if(t < 40) return b ^ c ^ d;
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if(t < 60) return (b & c) | (b & d) | (c & d);
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return b ^ c ^ d;
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}
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/*
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* Determine the appropriate additive constant for the current iteration
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*/
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function kt(t)
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{
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return (t < 20) ? 1518500249 : (t < 40) ? 1859775393 :
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(t < 60) ? -1894007588 : -899497514;
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}
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/*
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* Take a string and return the hex representation of its SHA-1.
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*/
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function calcSHA1(str)
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{
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var x = str2blks_SHA1(str);
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var w = new Array(80);
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var a = 1732584193;
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var b = -271733879;
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var c = -1732584194;
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var d = 271733878;
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var e = -1009589776;
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for(var i = 0; i < x.length; i += 16)
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{
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var olda = a;
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var oldb = b;
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var oldc = c;
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var oldd = d;
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var olde = e;
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for(var j = 0; j < 80; j++)
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{
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if(j < 16) w[j] = x[i + j];
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else w[j] = rol(w[j-3] ^ w[j-8] ^ w[j-14] ^ w[j-16], 1);
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t = add(add(rol(a, 5), ft(j, b, c, d)), add(add(e, w[j]), kt(j)));
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e = d;
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d = c;
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c = rol(b, 30);
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b = a;
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a = t;
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}
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a = add(a, olda);
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b = add(b, oldb);
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c = add(c, oldc);
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d = add(d, oldd);
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e = add(e, olde);
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}
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return hex(a) + hex(b) + hex(c) + hex(d) + hex(e);
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}
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