final int start = dstIndex;

        this.dataOffset = dstIndex - this.headerStart + 26; // 26 = off from here to pad

        this.pad = (this.dataOffset - this.headerStart) % 4;
        this.pad = this.pad == 0 ? 0 : 4 - this.pad;
        this.dataOffset += this.pad;

        SMBUtil.writeInt2(this.fid, dst, dstIndex);
        dstIndex += 2;
        SMBUtil.writeInt4(this.offset, dst, dstIndex);

    @Test
    @DisplayName("Test pad calculation with various offsets")
    void testPadCalculation() {
        // Test pad calculation with different alignment values
        assertEquals(0, transaction.pad(0)); // Already aligned
        assertEquals(0, transaction.pad(4)); // Already aligned
        assertEquals(0, transaction.pad(8)); // Already aligned
        assertEquals(3, transaction.pad(1)); // Need 3 bytes to align to 4

                pad = parameterOffset % PADDING_SIZE;
                pad = pad == 0 ? 0 : PADDING_SIZE - pad;
                parameterOffset += pad;
            }

            // caclulate parameterDisplacement before calculating new parameterCount
            parameterDisplacement += parameterCount;

            int available = maxBufferSize - parameterOffset - pad;

        }

        return bufferIndex - start;
    }

    @Override
    int readBytesWireFormat(final byte[] buffer, int bufferIndex) {
        pad = pad1 = 0;
        final int n;

        if (parameterCount > 0) {
            bufferIndex += pad = parameterOffset - (bufferIndex - headerStart);
            System.arraycopy(buffer, bufferIndex, txn_buf, bufParameterStart + parameterDisplacement, parameterCount);

    }

    @Override
    protected int readBytesWireFormat(final byte[] buffer, int bufferIndex) throws SMBProtocolDecodingException {
        this.pad = this.pad1 = 0;
        if (this.parameterCount > 0) {
            bufferIndex += this.pad = this.parameterOffset - (bufferIndex - this.headerStart);

        bufferIndex += 4;

        final int pad = bufferIndex - (getHeaderStart() + securityBufferOffset);
        this.blob = new byte[securityBufferLength];
        System.arraycopy(buffer, getHeaderStart() + securityBufferOffset, this.blob, 0, securityBufferLength);
        bufferIndex += pad;
        bufferIndex += securityBufferLength;

        return bufferIndex - start;
    }

        final int start = dstIndex;

        dataOffset = dstIndex - headerStart + 26; // 26 = off from here to pad

        pad = (dataOffset - headerStart) % 4;
        pad = pad == 0 ? 0 : 4 - pad;
        dataOffset += pad;

        writeInt2(fid, dst, dstIndex);
        dstIndex += 2;
        writeInt4(offset, dst, dstIndex);
        dstIndex += 4;

        final int i = inData[inIndex] & 0xff;
        outData[outIndex] = ENCODE_TABLE[i >> 2];
        outData[outIndex + 1] = ENCODE_TABLE[i << 4 & 0x3f];
        outData[outIndex + 2] = PAD;
        outData[outIndex + 3] = PAD;
    }

    private static void encode1pad(final byte[] inData, final int inIndex, final char[] outData, final int outIndex) {

     */
    public Smb2TransformHeader(final byte[] nonce, final int originalMessageSize, final int flags, final long sessionId) {
        if (nonce.length == 12) {
            // For CCM cipher, pad nonce to 16 bytes with zeros
            System.arraycopy(nonce, 0, this.nonce, 0, 12);
            // Last 4 bytes remain zero-initialized
        } else if (nonce.length == 16) {

                off += 27;
                resp.decode(BUF, 4);
                /* EMC can send pad w/o data */
                final int pad = r.dataOffset - off;
                if (r.byteCount > 0 && pad > 0 && pad < 4) {
                    readn(in, BUF, 4 + off, pad);
                }

                if (r.dataLength > 0) {