/** SMB2 create/open file command */
    protected static final short SMB2_CREATE = 0x0005;
    /** SMB2 close file command */
    protected static final short SMB2_CLOSE = 0x0006;
    /** SMB2 flush file command */
    protected static final short SMB2_FLUSH = 0x0007;
    /** SMB2 read file command */
    protected static final short SMB2_READ = 0x0008;
    /** SMB2 write file command */

# ADR-0008 - Use NullAway for null checking

## Date

2025-08-06

## Context

Our codebase uses `null` extensively to represent an absence of value or optionality of the argument.
We utilize nullness annotations in Java code and somewhat rely on IDE warnings to guide us.
However, the Java code we have is not fully annotated, which causes several consequences:
* IDE warnings can be misleading

            // Initialize the data buffer with proper SMB2 header structure
            SMBUtil.writeInt4(0xFE534D42, data, 0); // SMB2 signature
            SMBUtil.writeInt4(0x0000, data, 12); // Command = 0
            SMBUtil.writeInt4(0x0000, data, 16); // Flags = 0

            CommonServerMessageBlock request = mock(CommonServerMessageBlock.class);
            CommonServerMessageBlock response = mock(CommonServerMessageBlock.class);

        // Credit charge
        SMBUtil.writeInt2(1, buffer, headerStart + 6);
        // Status
        SMBUtil.writeInt4(0, buffer, headerStart + 8);
        // Command (READ = 0x0008)
        SMBUtil.writeInt2(0x0008, buffer, headerStart + 12);
        // Credit request/response
        SMBUtil.writeInt2(1, buffer, headerStart + 14);
        // Flags
        SMBUtil.writeInt4(0, buffer, headerStart + 16);

     */
    public static final int CIPHER_AES_256_CCM = 0x0003;
    /**
     * AES-256-GCM cipher identifier for SMB3.1.1 encryption (future support)
     */
    public static final int CIPHER_AES_256_GCM = 0x0004;

    /**
     * Transform header flag indicating the message is encrypted
     */
    public static final int TRANSFORM_FLAG_ENCRYPTED = 0x0001;

    /**
     * Create encryption context
     *

 * @author Bin Zhu
 * @author Colin Decker
 * @since 1.0
 */
@J2ktIncompatible
@GwtIncompatible
public final class CharStreams {

  // 2K chars (4K bytes)
  private static final int DEFAULT_BUF_SIZE = 0x800;

  /** Creates a new {@code CharBuffer} for buffering reads or writes. */
  static CharBuffer createBuffer() {
    return CharBuffer.allocate(DEFAULT_BUF_SIZE);
  }

  private CharStreams() {}

  /**

    @DisplayName("Should support AES-256 cipher constants")
    void testAES256CipherConstants() {
        // Verify AES-256 constants are defined
        assertEquals(0x0003, Smb2EncryptionContext.CIPHER_AES_256_CCM, "AES-256-CCM constant should be defined");
        assertEquals(0x0004, Smb2EncryptionContext.CIPHER_AES_256_GCM, "AES-256-GCM constant should be defined");

        // Test creating context with AES-256 cipher IDs

"".main STEXT size=74 args=0x0 locals=0x10
	0x0000 00000 (x.go:3)	TEXT	"".main(SB), $16-0
	0x0000 00000 (x.go:3)	MOVQ	(TLS), CX
	0x0009 00009 (x.go:3)	CMPQ	SP, 16(CX)
	0x000d 00013 (x.go:3)	JLS	67
	0x000f 00015 (x.go:3)	SUBQ	$16, SP
	0x0013 00019 (x.go:3)	MOVQ	BP, 8(SP)
	0x0018 00024 (x.go:3)	LEAQ	8(SP), BP
	0x001d 00029 (x.go:3)	FUNCDATA	$0, gclocals·33cdeccccebe80329f1fdbee7f5874cb(SB)

     */
    public static final int ATTR_ARCHIVE = 0x20;

    // extended file attribute encoding(others same as above)
    static final int ATTR_COMPRESSED = 0x800;
    static final int ATTR_NORMAL = 0x080;
    static final int ATTR_TEMPORARY = 0x100;

    static final int ATTR_GET_MASK = 0x7FFF; /* orig 0x7fff */
    static final int ATTR_SET_MASK = 0x30A7; /* orig 0x0027 */

                try (SmbFileHandleImpl f = openUnshared(O_RDONLY, FILE_WRITE_ATTRIBUTES, FILE_SHARE_READ | FILE_SHARE_WRITE, dir,
                        dir != 0 ? 0x0001 : 0x0040)) {
                    th.send(new Trans2SetFileInformation(th.getConfig(), f.getFid(), attrs | dir, ctime, mtime, atime),