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Diffstat (limited to 'srp/cryptoHelpers.js')
| -rw-r--r-- | srp/cryptoHelpers.js | 185 |
1 files changed, 185 insertions, 0 deletions
diff --git a/srp/cryptoHelpers.js b/srp/cryptoHelpers.js new file mode 100644 index 0000000..a77ee42 --- /dev/null +++ b/srp/cryptoHelpers.js @@ -0,0 +1,185 @@ +/* + * cryptoHelpers.js: implements AES - Advanced Encryption Standard + * from the SlowAES project, http://code.google.com/p/slowaes/ + * + * Copyright (c) 2008 Josh Davis ( http://www.josh-davis.org ), + * Mark Percival ( http://mpercival.com ), + * Johan Sundstrom ( http://ecmanaut.blogspot.com ), + * John Resig ( http://ejohn.org ) + * + * Licensed under the Apache License, Version 2.0 + * http://www.apache.org/licenses/ + */ + + + +var cryptoHelpers = { + + // encodes a unicode string to UTF8 (8 bit characters are critical to AES functioning properly) + encode_utf8:function(s) + { + try{return unescape(encodeURIComponent(s));} + catch(e){throw 'error during utf8 encoding: cryptoHelpers.encode_utf8.';} + }, + + + // decodes a UTF8 string back to unicode + decode_utf8:function(s) + { + try{return decodeURIComponent(escape(s));} + catch(e){throw('error during utf8 decoding: cryptoHelpers.decode_utf8.');} + }, + + //convert a number array to a hex string + toHex:function() + { + var array = []; + if(arguments.length == 1 && arguments[0].constructor == Array) + array = arguments[0]; + else + array = arguments; + var ret = ''; + for(var i = 0;i < array.length;i++) + ret += (array[i] < 16 ? '0' : '') + array[i].toString(16); + return ret.toLowerCase(); + }, + + //convert a hex string to a number array + toNumbers:function(s) + { + var ret = []; + s.replace(/(..)/g,function(s){ + ret.push(parseInt(s,16)); + }); + return ret; + }, + + // get a random number in the range [min,max] + getRandom:function(min,max) + { + if(min === null) + min = 0; + if(max === null) + max = 1; + return Math.floor(Math.random()*(max+1)) + min; + }, + + generateSharedKey:function(len) + { + if(len === null) + len = 16; + var key = []; + for(var i = 0; i < len*2; i++) + key.push(this.getRandom(0,255)); + return key; + }, + + generatePrivateKey:function(s,size) + { + var sha = jsHash.sha2.arr_sha256(s); + return sha.slice(0,size); + }, + + convertStringToByteArray: function(s) + { + var byteArray = []; + for(var i = 0;i < s.length;i++) + { + byteArray.push(s.charCodeAt(i)); + } + return byteArray; + }, + + convertByteArrayToString: function(byteArray) + { + var s = ''; + for(var i = 0;i < byteArray.length;i++) + { + s += String.fromCharCode(byteArray[i]); + } + return s; + }, + + base64: { + // Takes a Nx16x1 byte array and converts it to Base64 + + chars: [ + 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', + 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', + 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', + 'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f', + 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', + 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', + 'w', 'x', 'y', 'z', '0', '1', '2', '3', + '4', '5', '6', '7', '8', '9', '+', '/', + '=' // for decoding purposes + ], + + encode_line: function(flatArr){ + var b64 = ''; + + for (var i = 0; i < flatArr.length; i += 3){ + b64 += this.chars[flatArr[i] >> 2]; + b64 += this.chars[((flatArr[i] & 3) << 4) | (flatArr[i + 1] >> 4)]; + if (!(flatArr[i + 1] === null)){ + b64 += this.chars[((flatArr[i + 1] & 15) << 2) | (flatArr[i + 2] >> 6)]; + }else{ + b64 += '='; + } + if (!(flatArr[i + 2] === null)){ + b64 += this.chars[flatArr[i + 2] & 63]; + }else{ + b64 += '='; + } + } + return b64; + }, + + encode: function(flatArr) + { + var b64 = this.encode_line(flatArr); + // OpenSSL is super particular about line breaks + var broken_b64 = b64.slice(0, 64) + '\n'; + for (var i = 1; i < (Math.ceil(b64.length / 64)); i++) + { + broken_b64 += b64.slice(i * 64, i * 64 + 64) + (Math.ceil(b64.length / 64) == i + 1 ? '': '\n'); + } + return broken_b64; + }, + + decode: function(string) + { + string = string.replace(/[\r\n\t ]+/g, '') + '===='; // drop all whitespaces and pad with '=' (end of b64 marker) + var flatArr = []; + var c = []; + //var b = []; + for (var i = 0; true ; i = i + 4){ + c[0] = this.chars.indexOf(string.charAt(i)); + if(c[0] == 64){ + return flatArr; + } + c[1] = this.chars.indexOf(string.charAt(i + 1)); + c[2] = this.chars.indexOf(string.charAt(i + 2)); + c[3] = this.chars.indexOf(string.charAt(i + 3)); + + if( + (c[0] < 0) || // char1 is wrong + (c[1] < 0) || (c[1] == 64) || // char2 is wrong + (c[2] < 0) || // char3 is neither an valid char nor '=' + (c[3] < 0) // char4 is neither an valid char nor '=' + ){ + throw 'error during base64 decoding at pos '+i+': cryptoHelpers.base64.decode.'; + } + + flatArr.push((c[0] << 2) | (c[1] >> 4)); + if(c[2] >= 0 && c[2] < 64){ + flatArr.push(((c[1] & 15) << 4) | (c[2] >> 2)); + if(c[3] >= 0 && c[2] < 64){ + flatArr.push(((c[2] & 3) << 6) | c[3]); + } + } + } + } + } +}; + |