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@lancecarlson
Created July 15, 2013 20:44
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var base64map = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
// Global Crypto object
var Crypto = exports.Crypto = {};
// Crypto utilities
var util = Crypto.util = {
// Bit-wise rotate left
rotl: function (n, b) {
return (n << b) | (n >>> (32 - b));
},
// Bit-wise rotate right
rotr: function (n, b) {
return (n << (32 - b)) | (n >>> b);
},
// Swap big-endian to little-endian and vice versa
endian: function (n) {
// If number given, swap endian
if (n.constructor == Number) {
return util.rotl(n, 8) & 0x00FF00FF |
util.rotl(n, 24) & 0xFF00FF00;
}
// Else, assume array and swap all items
for (var i = 0; i < n.length; i++)
n[i] = util.endian(n[i]);
return n;
},
// Generate an array of any length of random bytes
randomBytes: function (n) {
for (var bytes = []; n > 0; n--)
bytes.push(Math.floor(Math.random() * 256));
return bytes;
},
// Convert a byte array to big-endian 32-bit words
bytesToWords: function (bytes) {
for (var words = [], i = 0, b = 0; i < bytes.length; i++, b += 8)
words[b >>> 5] |= bytes[i] << (24 - b % 32);
return words;
},
// Convert big-endian 32-bit words to a byte array
wordsToBytes: function (words) {
for (var bytes = [], b = 0; b < words.length * 32; b += 8)
bytes.push((words[b >>> 5] >>> (24 - b % 32)) & 0xFF);
return bytes;
},
// Convert a byte array to a hex string
bytesToHex: function (bytes) {
for (var hex = [], i = 0; i < bytes.length; i++) {
hex.push((bytes[i] >>> 4).toString(16));
hex.push((bytes[i] & 0xF).toString(16));
}
return hex.join("");
},
// Convert a hex string to a byte array
hexToBytes: function (hex) {
for (var bytes = [], c = 0; c < hex.length; c += 2)
bytes.push(parseInt(hex.substr(c, 2), 16));
return bytes;
},
// Convert a string to a base-64 string
stringToBase64: function (str, encoding) {
var bytes;
if ( typeof encoding != 'string') {
bytes = UTF8.stringToBytes(str);
} else if ( encoding.toLowerCase() == 'binary' ) {
bytes = Binary.stringToBytes(str);
} else if ( encoding.toLowerCase() == 'utf8' || encoding.toLowerCase() == 'utf-8' ) {
bytes = UTF8.stringToBytes(str);
} else {
bytes = UTF8.stringToBytes(str);
}
return this.bytesToBase64(bytes);
},
// Convert a base-64 string to origin string
base64ToString: function (base64, encoding) {
var bytes, str;
bytes = this.base64ToBytes(base64);
if ( typeof encoding != 'string') {
str = UTF8.bytesToString(bytes);
} else if ( encoding.toLowerCase() == 'binary' ) {
str = Binary.bytesToString(bytes);
} else if ( encoding.toLowerCase() == 'utf8' || encoding.toLowerCase() == 'utf-8' ) {
str = UTF8.bytesToString(bytes);
} else {
str = UTF8.bytesToString(bytes);
}
return str;
},
// Convert a byte array to a base-64 string
bytesToBase64: function (bytes) {
// Use browser-native function if it exists
if (typeof btoa == "function") return btoa(Binary.bytesToString(bytes));
for(var base64 = [], i = 0; i < bytes.length; i += 3) {
var triplet = (bytes[i] << 16) | (bytes[i + 1] << 8) | bytes[i + 2];
for (var j = 0; j < 4; j++) {
if (i * 8 + j * 6 <= bytes.length * 8)
base64.push(base64map.charAt((triplet >>> 6 * (3 - j)) & 0x3F));
else base64.push("=");
}
}
return base64.join("");
},
// Convert a base-64 string to a byte array
base64ToBytes: function (base64) {
// Use browser-native function if it exists
if (typeof atob == "function") return Binary.stringToBytes(atob(base64));
// Remove non-base-64 characters
base64 = base64.replace(/[^A-Z0-9+\/]/ig, "");
for (var bytes = [], i = 0, imod4 = 0; i < base64.length; imod4 = ++i % 4) {
if (imod4 == 0) continue;
bytes.push(((base64map.indexOf(base64.charAt(i - 1)) & (Math.pow(2, -2 * imod4 + 8) - 1)) << (imod4 * 2)) |
(base64map.indexOf(base64.charAt(i)) >>> (6 - imod4 * 2)));
}
return bytes;
}
};
// Crypto character encodings
var charenc = Crypto.charenc = {};
// UTF-8 encoding
var UTF8 = charenc.UTF8 = {
// Convert a string to a byte array
stringToBytes: function (str) {
return Binary.stringToBytes(unescape(encodeURIComponent(str)));
},
// Convert a byte array to a string
bytesToString: function (bytes) {
return decodeURIComponent(escape(Binary.bytesToString(bytes)));
}
};
// Binary encoding
var Binary = charenc.Binary = {
// Convert a string to a byte array
stringToBytes: function (str) {
for (var bytes = [], i = 0; i < str.length; i++)
bytes.push(str.charCodeAt(i) & 0xFF);
return bytes;
},
// Convert a byte array to a string
bytesToString: function (bytes) {
for (var str = [], i = 0; i < bytes.length; i++)
str.push(String.fromCharCode(bytes[i]));
return str.join("");
}
};
// Shortcut
var util = Crypto.util;
// Convert n to unsigned 32-bit integer
util.u32 = function (n) {
return n >>> 0;
};
// Unsigned 32-bit addition
util.add = function () {
var result = this.u32(arguments[0]);
for (var i = 1; i < arguments.length; i++)
result = this.u32(result + this.u32(arguments[i]));
return result;
};
// Unsigned 32-bit multiplication
util.mult = function (m, n) {
return this.add((n & 0xFFFF0000) * m,
(n & 0x0000FFFF) * m);
};
// Unsigned 32-bit greater than (>) comparison
util.gt = function (m, n) {
return this.u32(m) > this.u32(n);
};
// Unsigned 32-bit less than (<) comparison
util.lt = function (m, n) {
return this.u32(m) < this.u32(n);
};
// Create pad namespace
var C_pad = Crypto.pad = {};
// Calculate the number of padding bytes required.
function _requiredPadding(cipher, message) {
var blockSizeInBytes = cipher._blocksize * 4;
var reqd = blockSizeInBytes - message.length % blockSizeInBytes;
return reqd;
};
// Remove padding when the final byte gives the number of padding bytes.
var _unpadLength = function (message) {
var pad = message.pop();
for (var i = 1; i < pad; i++) {
message.pop();
}
};
// No-operation padding, used for stream ciphers
C_pad.NoPadding = {
pad : function (cipher,message) {},
unpad : function (message) {}
};
// Zero Padding.
//
// If the message is not an exact number of blocks, the final block is
// completed with 0x00 bytes. There is no unpadding.
C_pad.ZeroPadding = {
pad : function (cipher, message) {
var blockSizeInBytes = cipher._blocksize * 4;
var reqd = message.length % blockSizeInBytes;
if( reqd!=0 ) {
for(reqd = blockSizeInBytes - reqd; reqd>0; reqd--) {
message.push(0x00);
}
}
},
unpad : function (message) {}
};
// ISO/IEC 7816-4 padding.
//
// Pads the plain text with an 0x80 byte followed by as many 0x00
// bytes are required to complete the block.
C_pad.iso7816 = {
pad : function (cipher, message) {
var reqd = _requiredPadding(cipher, message);
message.push(0x80);
for (; reqd > 1; reqd--) {
message.push(0x00);
}
},
unpad : function (message) {
while (message.pop() != 0x80) {}
}
};
// ANSI X.923 padding
//
// The final block is padded with zeros except for the last byte of the
// last block which contains the number of padding bytes.
C_pad.ansix923 = {
pad : function (cipher, message) {
var reqd = _requiredPadding(cipher, message);
for (var i = 1; i < reqd; i++) {
message.push(0x00);
}
message.push(reqd);
},
unpad : _unpadLength
};
// ISO 10126
//
// The final block is padded with random bytes except for the last
// byte of the last block which contains the number of padding bytes.
C_pad.iso10126 = {
pad : function (cipher, message) {
var reqd = _requiredPadding(cipher, message);
for (var i = 1; i < reqd; i++) {
message.push(Math.floor(Math.random() * 256));
}
message.push(reqd);
},
unpad : _unpadLength
};
// PKCS7 padding
//
// PKCS7 is described in RFC 5652. Padding is in whole bytes. The
// value of each added byte is the number of bytes that are added,
// i.e. N bytes, each of value N are added.
C_pad.pkcs7 = {
pad : function (cipher, message) {
var reqd = _requiredPadding(cipher, message);
for (var i = 0; i < reqd; i++) {
message.push(reqd);
}
},
unpad : _unpadLength
};
// Create mode namespace
var C_mode = Crypto.mode = {};
/**
* Mode base "class".
*/
var Mode = C_mode.Mode = function (padding) {
if (padding) {
this._padding = padding;
}
};
Mode.prototype = {
encrypt: function (cipher, m, iv) {
this._padding.pad(cipher, m);
this._doEncrypt(cipher, m, iv);
},
decrypt: function (cipher, m, iv) {
this._doDecrypt(cipher, m, iv);
this._padding.unpad(m);
},
// Default padding
_padding: C_pad.iso7816
};
/**
* Electronic Code Book mode.
*
* ECB applies the cipher directly against each block of the input.
*
* ECB does not require an initialization vector.
*/
var ECB = C_mode.ECB = function () {
// Call parent constructor
Mode.apply(this, arguments);
};
// Inherit from Mode
var ECB_prototype = ECB.prototype = new Mode;
// Concrete steps for Mode template
ECB_prototype._doEncrypt = function (cipher, m, iv) {
var blockSizeInBytes = cipher._blocksize * 4;
// Encrypt each block
for (var offset = 0; offset < m.length; offset += blockSizeInBytes) {
cipher._encryptblock(m, offset);
}
};
ECB_prototype._doDecrypt = function (cipher, c, iv) {
var blockSizeInBytes = cipher._blocksize * 4;
// Decrypt each block
for (var offset = 0; offset < c.length; offset += blockSizeInBytes) {
cipher._decryptblock(c, offset);
}
};
// ECB never uses an IV
ECB_prototype.fixOptions = function (options) {
options.iv = [];
};
/**
* Cipher block chaining
*
* The first block is XORed with the IV. Subsequent blocks are XOR with the
* previous cipher output.
*/
var CBC = C_mode.CBC = function () {
// Call parent constructor
Mode.apply(this, arguments);
};
// Inherit from Mode
var CBC_prototype = CBC.prototype = new Mode;
// Concrete steps for Mode template
CBC_prototype._doEncrypt = function (cipher, m, iv) {
var blockSizeInBytes = cipher._blocksize * 4;
// Encrypt each block
for (var offset = 0; offset < m.length; offset += blockSizeInBytes) {
if (offset == 0) {
// XOR first block using IV
for (var i = 0; i < blockSizeInBytes; i++)
m[i] ^= iv[i];
} else {
// XOR this block using previous crypted block
for (var i = 0; i < blockSizeInBytes; i++)
m[offset + i] ^= m[offset + i - blockSizeInBytes];
}
// Encrypt block
cipher._encryptblock(m, offset);
}
};
CBC_prototype._doDecrypt = function (cipher, c, iv) {
var blockSizeInBytes = cipher._blocksize * 4;
// At the start, the previously crypted block is the IV
var prevCryptedBlock = iv;
// Decrypt each block
for (var offset = 0; offset < c.length; offset += blockSizeInBytes) {
// Save this crypted block
var thisCryptedBlock = c.slice(offset, offset + blockSizeInBytes);
// Decrypt block
cipher._decryptblock(c, offset);
// XOR decrypted block using previous crypted block
for (var i = 0; i < blockSizeInBytes; i++) {
c[offset + i] ^= prevCryptedBlock[i];
}
prevCryptedBlock = thisCryptedBlock;
}
};
/**
* Cipher feed back
*
* The cipher output is XORed with the plain text to produce the cipher output,
* which is then fed back into the cipher to produce a bit pattern to XOR the
* next block with.
*
* This is a stream cipher mode and does not require padding.
*/
var CFB = C_mode.CFB = function () {
// Call parent constructor
Mode.apply(this, arguments);
};
// Inherit from Mode
var CFB_prototype = CFB.prototype = new Mode;
// Override padding
CFB_prototype._padding = C_pad.NoPadding;
// Concrete steps for Mode template
CFB_prototype._doEncrypt = function (cipher, m, iv) {
var blockSizeInBytes = cipher._blocksize * 4,
keystream = iv.slice(0);
// Encrypt each byte
for (var i = 0; i < m.length; i++) {
var j = i % blockSizeInBytes;
if (j == 0) cipher._encryptblock(keystream, 0);
m[i] ^= keystream[j];
keystream[j] = m[i];
}
};
CFB_prototype._doDecrypt = function (cipher, c, iv) {
var blockSizeInBytes = cipher._blocksize * 4,
keystream = iv.slice(0);
// Encrypt each byte
for (var i = 0; i < c.length; i++) {
var j = i % blockSizeInBytes;
if (j == 0) cipher._encryptblock(keystream, 0);
var b = c[i];
c[i] ^= keystream[j];
keystream[j] = b;
}
};
/**
* Output feed back
*
* The cipher repeatedly encrypts its own output. The output is XORed with the
* plain text to produce the cipher text.
*
* This is a stream cipher mode and does not require padding.
*/
var OFB = C_mode.OFB = function () {
// Call parent constructor
Mode.apply(this, arguments);
};
// Inherit from Mode
var OFB_prototype = OFB.prototype = new Mode;
// Override padding
OFB_prototype._padding = C_pad.NoPadding;
// Concrete steps for Mode template
OFB_prototype._doEncrypt = function (cipher, m, iv) {
var blockSizeInBytes = cipher._blocksize * 4,
keystream = iv.slice(0);
// Encrypt each byte
for (var i = 0; i < m.length; i++) {
// Generate keystream
if (i % blockSizeInBytes == 0)
cipher._encryptblock(keystream, 0);
// Encrypt byte
m[i] ^= keystream[i % blockSizeInBytes];
}
};
OFB_prototype._doDecrypt = OFB_prototype._doEncrypt;
/**
* Counter
* @author Gergely Risko
*
* After every block the last 4 bytes of the IV is increased by one
* with carry and that IV is used for the next block.
*
* This is a stream cipher mode and does not require padding.
*/
var CTR = C_mode.CTR = function () {
// Call parent constructor
Mode.apply(this, arguments);
};
// Inherit from Mode
var CTR_prototype = CTR.prototype = new Mode;
// Override padding
CTR_prototype._padding = C_pad.NoPadding;
CTR_prototype._doEncrypt = function (cipher, m, iv) {
var blockSizeInBytes = cipher._blocksize * 4;
for (var i = 0; i < m.length;) {
// do not lose iv
var keystream = iv.slice(0);
// Generate keystream for next block
cipher._encryptblock(keystream, 0);
// XOR keystream with block
for (var j = 0; i < m.length && j < blockSizeInBytes; j++, i++) {
m[i] ^= keystream[j];
}
// Increase IV
if(++(iv[blockSizeInBytes-1]) == 256) {
iv[blockSizeInBytes-1] = 0;
if(++(iv[blockSizeInBytes-2]) == 256) {
iv[blockSizeInBytes-2] = 0;
if(++(iv[blockSizeInBytes-3]) == 256) {
iv[blockSizeInBytes-3] = 0;
++(iv[blockSizeInBytes-4]);
}
}
}
}
};
CTR_prototype._doDecrypt = CTR_prototype._doEncrypt;
log('test');
var TEST = exports.TEST = function(test) {
return 'blah';
};
var Crypto = exports.Crypto = require('./lib/crypto').Crypto;
[ 'test'
].forEach( function (path) {
var m = require('./lib/' + path);
log('loaded module')
log(m)
for ( var i in m ) {
Crypto[i] = m[i];
}
});
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