sjcl cypher

cypher.coffee

sjcl = require("../bower_components/sjcl/sjcl.js")

decrypt = (ciphertext, password, p) ->
    salt = sjcl.codec.hex.toBits(p.salt)
    iv = sjcl.codec.hex.toBits(p.iv)
    ct = sjcl.codec.bytes.toBits(ciphertext)
    key = sjcl.misc.pbkdf2(password, salt, p.iter).slice(0, p.ks / 32)
    prp = new sjcl.cipher[p.cipher](key)
    text = sjcl.mode[p.mode].decrypt(prp, ct, iv, p.auth, p.ts)
    return sjcl.codec.utf8String.fromBits(text)
    
encrypt = (message, password, p) ->
    iv = sjcl.random.randomWords(4, 0)
    p.iv = sjcl.codec.hex.fromBits(iv)
    salt = sjcl.random.randomWords(2, 0)
    p.salt = sjcl.codec.hex.fromBits(salt)
    key = sjcl.misc.pbkdf2(password, salt, p.iter).slice(0, p.ks / 32)
    msg = sjcl.codec.utf8String.toBits(message)
    auth = sjcl.codec.utf8String.toBits(p.auth)
    prp = new sjcl.cipher[p.cipher](key)
    ct = sjcl.mode[p.mode].encrypt(prp, msg, iv, auth, p.ts);
    return sjcl.codec.bytes.fromBits(ct)