From:http://pajhome.org.uk/crypt/md5/sha1src.html
/* * 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; var b64pad = ""; var chrsz = 8; /* * 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){ 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;}