javascript-blowfish

Blowfish encryption library Javascript, jquery,coffeescript (blowfish.js)

Blowfish is block cipher, block length is 8 byte.

Online DEMO of javascript-blowfish.

A key advantage of the library is that it works correctly with strings in UTF-8.

Text data encryption (ASCII/text)

It you want to encrypt string information (like text-message, or json, xml): use trimZeroes method (see bellow Example 1).

Example: ECB mode, default

var bf = new Blowfish("secret key");
var encrypted = bf.encrypt("secret message");
var decrypted = bf.decrypt(encrypted);
decrypted = bf.trimZeroes(decrypted); // for string/text information 
console.log(decrypted);

Binary data encryption

If you want to encrypt binary data you must provide encrypt function with string length multiple by 8.

Example:

Input string for encryption: "asdf" (4 bytes) is not enough. Blowfish want 8-byte string (or 16, 24, 32,...)

So my lib automaticaly pad string with zeros: "asdf\0\0\0\0" If you want to prevent such behaviour you should pad input data to block size.

Additional info about padding: Using Padding in Encryption (@lucnap) suggested

After decryption we will get not "asdf", but "asdf\0\0\0\0" string.

Example 2: CBC mode (better for encrypting long messages and images).

For CBC you need additional key (CBC Vector) which length should be 8 bytes.

var bf = new Blowfish("key", "cbc");
var encrypted = bf.encrypt("secret message", "cbcvecto");
var decrypted = bf.decrypt(encrypted, "cbcvecto");

Blowfish when encrypt produces binary string as result. It's not usable for example, to copy paste. We could encode it to base64 text format:

Example 3: with base64 encoded output

var bf = new Blowfish("key");

// Encrypt and encode to base64
var encrypted = bf.base64Encode(bf.encrypt("secret message"));
console.log(encrypted);

// Decrypt
var encrypted = bf.base64Decode(encrypted);
var decrypted = bf.decrypt(encrypted);