CommonAce.cs

using System.Security.Principal;

namespace System.Security.AccessControl
{
    public sealed class CommonAce : QualifiedAce
    {
        public override int BinaryLength => 8 + base.SecurityIdentifier.BinaryLength + base.OpaqueLength;

        internal override int MaxOpaqueLengthInternal => MaxOpaqueLength(base.IsCallback);

        public CommonAce(AceFlags flags, AceQualifier qualifier, int accessMask, SecurityIdentifier sid, bool isCallback, byte[] opaque)
            : base(TypeFromQualifier(isCallback, qualifier), flags, accessMask, sid, opaque)
        {
        }

        private static AceType TypeFromQualifier(bool isCallback, AceQualifier qualifier)
        {
            switch (qualifier)
            {
            case AceQualifier.AccessAllowed:
                if (!isCallback)
                {
                    return AceType.AccessAllowed;
                }
                return AceType.AccessAllowedCallback;
            case AceQualifier.AccessDenied:
                if (!isCallback)
                {
                    return AceType.AccessDenied;
                }
                return AceType.AccessDeniedCallback;
            case AceQualifier.SystemAudit:
                if (!isCallback)
                {
                    return AceType.SystemAudit;
                }
                return AceType.SystemAuditCallback;
            case AceQualifier.SystemAlarm:
                if (!isCallback)
                {
                    return AceType.SystemAlarm;
                }
                return AceType.SystemAlarmCallback;
            default:
                throw new ArgumentOutOfRangeException("qualifier", Environment.GetResourceString("ArgumentOutOfRange_Enum"));
            }
        }

        internal static bool ParseBinaryForm(byte[] binaryForm, int offset, out AceQualifier qualifier, out int accessMask, out SecurityIdentifier sid, out bool isCallback, out byte[] opaque)
        {
            GenericAce.VerifyHeader(binaryForm, offset);
            if (binaryForm.Length - offset >= 8 + SecurityIdentifier.MinBinaryLength)
            {
                AceType aceType = (AceType)binaryForm[offset];
                if (aceType == AceType.AccessAllowed || aceType == AceType.AccessDenied || aceType == AceType.SystemAudit || aceType == AceType.SystemAlarm)
                {
                    isCallback = false;
                }
                else
                {
                    if (aceType != AceType.AccessAllowedCallback && aceType != AceType.AccessDeniedCallback && aceType != AceType.SystemAuditCallback && aceType != AceType.SystemAlarmCallback)
                    {
                        goto IL_0116;
                    }
                    isCallback = true;
                }
                if (aceType == AceType.AccessAllowed || aceType == AceType.AccessAllowedCallback)
                {
                    qualifier = AceQualifier.AccessAllowed;
                }
                else if (aceType == AceType.AccessDenied || aceType == AceType.AccessDeniedCallback)
                {
                    qualifier = AceQualifier.AccessDenied;
                }
                else if (aceType == AceType.SystemAudit || aceType == AceType.SystemAuditCallback)
                {
                    qualifier = AceQualifier.SystemAudit;
                }
                else
                {
                    if (aceType != AceType.SystemAlarm && aceType != AceType.SystemAlarmCallback)
                    {
                        goto IL_0116;
                    }
                    qualifier = AceQualifier.SystemAlarm;
                }
                int num = offset + 4;
                int num2 = 0;
                accessMask = binaryForm[num + 0] + (binaryForm[num + 1] << 8) + (binaryForm[num + 2] << 16) + (binaryForm[num + 3] << 24);
                num2 += 4;
                sid = new SecurityIdentifier(binaryForm, num + num2);
                opaque = null;
                int num3 = (binaryForm[offset + 3] << 8) + binaryForm[offset + 2];
                if (num3 % 4 == 0)
                {
                    int num4 = num3 - 4 - 4 - (byte)sid.BinaryLength;
                    if (num4 > 0)
                    {
                        opaque = new byte[num4];
                        for (int i = 0; i < num4; i++)
                        {
                            opaque[i] = binaryForm[offset + num3 - num4 + i];
                        }
                    }
                    return true;
                }
            }
            goto IL_0116;
            IL_0116:
            qualifier = AceQualifier.AccessAllowed;
            accessMask = 0;
            sid = null;
            isCallback = false;
            opaque = null;
            return false;
        }

        public static int MaxOpaqueLength(bool isCallback)
        {
            return 65527 - SecurityIdentifier.MaxBinaryLength;
        }

        public override void GetBinaryForm(byte[] binaryForm, int offset)
        {
            MarshalHeader(binaryForm, offset);
            int num = offset + 4;
            int num2 = 0;
            binaryForm[num + 0] = (byte)base.AccessMask;
            binaryForm[num + 1] = (byte)(base.AccessMask >> 8);
            binaryForm[num + 2] = (byte)(base.AccessMask >> 16);
            binaryForm[num + 3] = (byte)(base.AccessMask >> 24);
            num2 += 4;
            base.SecurityIdentifier.GetBinaryForm(binaryForm, num + num2);
            num2 += base.SecurityIdentifier.BinaryLength;
            if (GetOpaque() != null)
            {
                if (base.OpaqueLength > MaxOpaqueLengthInternal)
                {
                    throw new SystemException();
                }
                GetOpaque().CopyTo(binaryForm, num + num2);
            }
        }
    }
}