mode-ofb-test.js

YUI.add('mode-ofb-test', function (Y) {
    var C = CryptoJS;

    Y.Test.Runner.add(new Y.Test.Case({
        name: 'OFB',

        setUp: function () {
            this.data = {};

            this.data.message = C.lib.WordArray.create([
                0x00010203, 0x04050607, 0x08090a0b, 0x0c0d0e0f,
                0x10111213, 0x14151617, 0x18191a1b, 0x1c1d1e1f
            ]);
            this.data.key = C.lib.WordArray.create([0x20212223, 0x24252627, 0x28292a2b, 0x2c2d2e2f]);
            this.data.iv = C.lib.WordArray.create([0x30313233, 0x34353637, 0x38393a3b, 0x3c3d3e3f]);
        },

        testEncryptor: function () {
            // Compute expected
            var expected = this.data.message.clone();
            var aes = C.algo.AES.createEncryptor(this.data.key);

            // First block XORed with encrypted IV
            var keystream = this.data.iv.words.slice(0);
            aes.encryptBlock(keystream, 0);
            for (var i = 0; i < 4; i++) {
                expected.words[i] ^= keystream[i];
            }

            // Subsequent blocks XORed with encrypted previous keystream
            aes.encryptBlock(keystream, 0);
            for (var i = 4; i < 8; i++) {
                expected.words[i] ^= keystream[i % 4];
            }

            // Compute actual
            var actual = C.AES.encrypt(this.data.message, this.data.key, { iv: this.data.iv, mode: C.mode.OFB, padding: C.pad.NoPadding }).ciphertext;

            // Test
            Y.Assert.areEqual(expected.toString(), actual.toString());
        },

        testDecryptor: function () {
            var encrypted = C.AES.encrypt(this.data.message, this.data.key, { iv: this.data.iv, mode: C.mode.OFB, padding: C.pad.NoPadding });
            var decrypted = C.AES.decrypt(encrypted, this.data.key, { iv: this.data.iv, mode: C.mode.OFB, padding: C.pad.NoPadding });

            Y.Assert.areEqual(this.data.message.toString(), decrypted.toString());
        }
    }));
}, '$Rev$');