Fix SID equality and WellKnownSid mappings

1 files changed, 62 insertions, 17 deletions

diff --git a/SecurityIdentifier.cs b/SecurityIdentifier.cs
index c3f11ef..075788d 100644
--- a/SecurityIdentifier.cs
+++ b/SecurityIdentifier.cs
@@ -1,16 +1,43 @@
 using Microsoft.EntityFrameworkCore.Storage.ValueConversion;
+using System.Diagnostics.CodeAnalysis;
 using System.Numerics;
 using System.Runtime.InteropServices;
+using System.Security.Cryptography.X509Certificates;
 using System.Text.RegularExpressions;
 
 namespace HyperBooru;
 
-public enum WellKnownSidType {
-    NullSid,
-    WorldSid,
-    LocalSid,
-    CreatorOwnerSid,
-    CreatorGroupSid
+public static class WellKnownSid {
+    public static readonly SecurityIdentifier NullSid         = new("S-1-0-0");
+    public static readonly SecurityIdentifier WorldSid        = new("S-1-1-0");
+    public static readonly SecurityIdentifier LocalSid        = new("S-1-2-0");
+    public static readonly SecurityIdentifier CreatorOwnerSid = new("S-1-3-0");
+    public static readonly SecurityIdentifier CreatorGroupSid = new("S-1-3-1");
+
+    private static readonly (string name, SecurityIdentifier sid)[] nameMap = new[] {
+        ( "Everyone",      WorldSid        ),
+        ( "LOCAL",         LocalSid        ),
+        ( "CREATOR OWNER", CreatorGroupSid ),
+        ( "CREATOR GROUP", CreatorGroupSid )
+    };
+
+    public static SecurityIdentifier? TranslateName(string name) {
+        try {
+            return nameMap
+                .First(x => x.name.ToLower() == name.ToLower().Trim())
+                .sid;
+        } catch(InvalidOperationException) {
+            return null;
+        }
+    }
+
+    public static string? TranslateSid(SecurityIdentifier sid) {
+        try {
+            return nameMap.First(x => x.sid == sid).name;
+        } catch(InvalidOperationException) {
+            return null;
+        }
+    }
 }
 
 public class SecurityIdentifier {
@@ -19,17 +46,6 @@ public class SecurityIdentifier {
     private static readonly Regex SddlRegex =
         new(@"^S(-[0-9]+){2,}$", RegexOptions.Compiled);
 
-    private static readonly Dictionary<WellKnownSidType, string> wellKnownSidTypes = new() {
-        { HyperBooru.WellKnownSidType.NullSid,         "S-1-0-0" },
-        { HyperBooru.WellKnownSidType.WorldSid,        "S-1-1-0" },
-        { HyperBooru.WellKnownSidType.LocalSid,        "S-1-2-0" },
-        { HyperBooru.WellKnownSidType.CreatorOwnerSid, "S-1-3-0" },
-        { HyperBooru.WellKnownSidType.CreatorGroupSid, "S-1-3-1" }
-    };
-
-    public SecurityIdentifier(WellKnownSidType wellKnownSidType)
-        : this(wellKnownSidTypes[wellKnownSidType]) {}
-
     public SecurityIdentifier(string sddlForm) {
         var match = SddlRegex.Match(sddlForm);
         if(!match.Success)
@@ -119,6 +135,35 @@ public struct SidStruct {
     public byte[]   IdentifierAuthority;
     [MarshalAs(UnmanagedType.ByValArray)]
     public uint[]   SubAuthorities;
+
+    public static bool operator ==(SidStruct? x, SidStruct? y) =>
+        x?.Equals(y) ?? false;
+
+    public static bool operator !=(SidStruct? x, SidStruct? y) =>
+        !(x == y);
+
+    public override bool Equals([NotNullWhen(true)] object? obj) {
+        if(obj is null || obj is not SidStruct)
+            return false;
+
+        var sid = (SidStruct) obj;
+
+        return
+            Revision == sid.Revision &&
+            SubAuthorityCount == sid.SubAuthorityCount &&
+            Enumerable.SequenceEqual(IdentifierAuthority, sid.IdentifierAuthority) &&
+            Enumerable.SequenceEqual(SubAuthorities, sid.SubAuthorities);
+    }
+
+    public override int GetHashCode() => (
+        Revision,
+        SubAuthorityCount,
+        IdentifierAuthority
+            .Select(v => (uint) v)
+            .Aggregate(0, (a, v) => HashCode.Combine(a, v)),
+        SubAuthorities
+            .Aggregate(0, (a, v) => HashCode.Combine(a, v)))
+        .GetHashCode();
 }
 
 public class SecurityIdentifierConverter : ValueConverter<SecurityIdentifier, byte[]> {