| /base/000_base/node_modules/cryptojs/lib/MARC4.js |
|---|
| @@ -0,0 +1,117 @@ |
|---|
| (function(){ |
| |
| var C = (typeof window === 'undefined') ? require('./Crypto').Crypto : window.Crypto; |
| |
| // Shortcuts |
| var util = C.util, |
| charenc = C.charenc, |
| UTF8 = charenc.UTF8, |
| Binary = charenc.Binary; |
| |
| var MARC4 = C.MARC4 = { |
| |
| /** |
| * Public API |
| */ |
| |
| encrypt: function (message, password) { |
| |
| var |
| |
| // Convert to bytes |
| m = UTF8.stringToBytes(message), |
| |
| // Generate random IV |
| iv = util.randomBytes(16), |
| |
| // Generate key |
| k = password.constructor == String ? |
| // Derive key from passphrase |
| C.PBKDF2(password, iv, 32, { asBytes: true }) : |
| // else, assume byte array representing cryptographic key |
| password; |
| |
| // Encrypt |
| MARC4._marc4(m, k, 1536); |
| |
| // Return ciphertext |
| return util.bytesToBase64(iv.concat(m)); |
| |
| }, |
| |
| decrypt: function (ciphertext, password) { |
| |
| var |
| |
| // Convert to bytes |
| c = util.base64ToBytes(ciphertext), |
| |
| // Separate IV and message |
| iv = c.splice(0, 16), |
| |
| // Generate key |
| k = password.constructor == String ? |
| // Derive key from passphrase |
| C.PBKDF2(password, iv, 32, { asBytes: true }) : |
| // else, assume byte array representing cryptographic key |
| password; |
| |
| // Decrypt |
| MARC4._marc4(c, k, 1536); |
| |
| // Return plaintext |
| return UTF8.bytesToString(c); |
| |
| }, |
| |
| |
| /** |
| * Internal methods |
| */ |
| |
| // The core |
| _marc4: function (m, k, drop) { |
| |
| // State variables |
| var i, j, s, temp; |
| |
| // Key setup |
| for (i = 0, s = []; i < 256; i++) s[i] = i; |
| for (i = 0, j = 0; i < 256; i++) { |
| |
| j = (j + s[i] + k[i % k.length]) % 256; |
| |
| // Swap |
| temp = s[i]; |
| s[i] = s[j]; |
| s[j] = temp; |
| |
| } |
| |
| // Clear counters |
| i = j = 0; |
| |
| // Encryption |
| for (var k = -drop; k < m.length; k++) { |
| |
| i = (i + 1) % 256; |
| j = (j + s[i]) % 256; |
| |
| // Swap |
| temp = s[i]; |
| s[i] = s[j]; |
| s[j] = temp; |
| |
| // Stop here if we're still dropping keystream |
| if (k < 0) continue; |
| |
| // Encrypt |
| m[k] ^= s[(s[i] + s[j]) % 256]; |
| |
| } |
| |
| } |
| |
| }; |
| |
| })(); |
