private static Key createDESKey(final byte[] bytes, final int offset) {
        final byte[] keyBytes = new byte[7];
        System.arraycopy(bytes, offset, keyBytes, 0, 7);
        final byte[] material = new byte[8];
        material[0] = keyBytes[0];
        material[1] = (byte) (keyBytes[0] << 7 | (keyBytes[1] & 0xff) >>> 1);
        material[2] = (byte) (keyBytes[1] << 6 | (keyBytes[2] & 0xff) >>> 2);
        material[3] = (byte) (keyBytes[2] << 5 | (keyBytes[3] & 0xff) >>> 3);
        material[4] = (byte) (keyBytes[3] << 4 | (keyBytes[4] & 0xff) >>> 4);
        material[5] = (byte) (keyBytes[4] << 3 | (keyBytes[5] & 0xff) >>> 5);
        material[6] = (byte) (keyBytes[5] << 2 | (keyBytes[6] & 0xff) >>> 6);
        material[7] = (byte) (keyBytes[6] << 1);
        oddParity(material);
        return new SecretKeySpec(material, "DES");
    }
Creates a DES encryption key from the given key material.

@param bytes
           A byte array containing the DES key material.
@param offset
           The offset in the given byte array at which the 7-byte key
           material starts.

@return A DES encryption key created from the key material starting at
        the specified offset in the given byte array.
httpclient5/src/main/java/org/apache/hc/client5/http/impl/auth/NTLMEngineImpl.java