Fix missing/incorrect checksums for Sega CD, Saturn, and Jaguar CD (s…

…quashed PR #4024) * Fix non-PSX disc hashing somewhat - Don't hash generated (empty) lead-in/lead-out tracks - Limit to track length, not absolute LBA of next track * Use `InformationTrackCount` instead of `Tracks.Count` * Add Jaguar CD hashing Reuse RetroAchievements implementation, move into `DiscHasher`
TASEmulators · Sep 14, 2024 · e2a6942 · e2a6942
1 parent 1b3e7d4
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Showing 3 changed files with 135 additions and 113 deletions.
diff --git a/src/BizHawk.Client.Common/RomLoader.cs b/src/BizHawk.Client.Common/RomLoader.cs
@@ -234,9 +234,7 @@ private GameInfo MakeGameFromDisc(Disc disc, string ext, string name)
 			// TODO - use more sophisticated IDer
 			var discType = new DiscIdentifier(disc).DetectDiscType();
 			var discHasher = new DiscHasher(disc);
-			var discHash = discType == DiscType.SonyPSX
-				? discHasher.Calculate_PSX_BizIDHash()
-				: discHasher.OldHash();
+			var discHash = discHasher.CalculateBizHash(discType);
 
 			var game = Database.CheckDatabase(discHash);
 			if (game is not null) return game;

diff --git a/src/BizHawk.Client.EmuHawk/RetroAchievements/RetroAchievements.GameVerification.cs b/src/BizHawk.Client.EmuHawk/RetroAchievements/RetroAchievements.GameVerification.cs
@@ -168,115 +168,12 @@ int GetFileSector(string filename, out int filesize)
 					buffer.AddRange(new ArraySegment<byte>(buf2048, 0, 512));
 					break;
 				case ConsoleID.JaguarCD:
-					// we want to hash the second session of the disc
-					if (disc.Sessions.Count > 2)
+					var discHasher = new DiscHasher(disc);
+					return discHasher.CalculateRAJaguarHash() switch
 					{
-						static string HashJaguar(DiscTrack bootTrack, DiscSectorReader dsr, bool commonHomebrewHash)
-						{
-							const string _jaguarHeader = "ATARI APPROVED DATA HEADER ATRI";
-							const string _jaguarBSHeader = "TARA IPARPVODED TA AEHDAREA RT";
-							var buffer = new List<byte>();
-							var buf2352 = new byte[2352];
-
-							// find the boot track header
-							// see https://github.com/TASEmulators/BizHawk/blob/f29113287e88c6a644dbff30f92a9833307aad20/waterbox/virtualjaguar/src/cdhle.cpp#L109-L145
-							var startLba = bootTrack.LBA;
-							var numLbas = bootTrack.NextTrack.LBA - bootTrack.LBA;
-							int bootLen = 0, bootLba = 0, bootOff = 0;
-							bool byteswapped = false, foundHeader = false;
-							var bootLenOffset = (commonHomebrewHash ? 0x40 : 0) + 32 + 4;
-							for (var i = 0; i < numLbas; i++)
-							{
-								dsr.ReadLBA_2352(startLba + i, buf2352, 0);
-
-								for (var j = 0; j < 2352 - bootLenOffset - 4; j++)
-								{
-									if (buf2352[j] == _jaguarHeader[0])
-									{
-										if (_jaguarHeader == Encoding.ASCII.GetString(buf2352, j, 32 - 1))
-										{
-											bootLen = (buf2352[j + bootLenOffset + 0] << 24) | (buf2352[j + bootLenOffset + 1] << 16) |
-												(buf2352[j + bootLenOffset + 2] << 8) | buf2352[j + bootLenOffset + 3];
-											bootLba = startLba + i;
-											bootOff = j + bootLenOffset + 4;
-											// byteswapped = false;
-											foundHeader = true;
-											break;
-										}
-									}
-									else if (buf2352[j] == _jaguarBSHeader[0])
-									{
-										if (_jaguarBSHeader == Encoding.ASCII.GetString(buf2352, j, 32 - 2))
-										{
-											bootLen = (buf2352[j + bootLenOffset + 1] << 24) | (buf2352[j + bootLenOffset + 0] << 16) |
-												(buf2352[j + bootLenOffset + 3] << 8) | buf2352[j + bootLenOffset + 2];
-											bootLba = startLba + i;
-											bootOff = j + bootLenOffset + 4;
-											byteswapped = true;
-											foundHeader = true;
-											break;
-										}
-									}
-								}
-
-								if (foundHeader)
-								{
-									break;
-								}
-							}
-
-							if (!foundHeader)
-							{
-								return null;
-							}
-
-							dsr.ReadLBA_2352(bootLba++, buf2352, 0);
-
-							if (byteswapped)
-							{
-								EndiannessUtils.MutatingByteSwap16(buf2352.AsSpan());
-							}
-
-							buffer.AddRange(new ArraySegment<byte>(buf2352, bootOff, Math.Min(2352 - bootOff, bootLen)));
-							bootLen -= 2352 - bootOff;
-
-							while (bootLen > 0)
-							{
-								dsr.ReadLBA_2352(bootLba++, buf2352, 0);
-
-								if (byteswapped)
-								{
-									EndiannessUtils.MutatingByteSwap16(buf2352.AsSpan());
-								}
-
-								buffer.AddRange(new ArraySegment<byte>(buf2352, 0, Math.Min(2352, bootLen)));
-								bootLen -= 2352;
-							}
-
-							return MD5Checksum.ComputeDigestHex(buffer.ToArray());
-						}
-
-						var jaguarHash = HashJaguar(disc.Sessions[2].Tracks[1], dsr, false);
-						switch (jaguarHash)
-						{
-							case null:
-								return 0;
-							case "254487B59AB21BC005338E85CBF9FD2F": // see https://github.com/RetroAchievements/rcheevos/pull/234
-							{
-								jaguarHash = HashJaguar(disc.Sessions[1].Tracks[2], dsr, true);
-								if (jaguarHash is null)
-								{
-									return 0;
-								}
-
-								break;
-							}
-						}
-
-						return IdentifyHash(jaguarHash);
-					}
-
-					return 0;
+						string jaguarHash => IdentifyHash(jaguarHash),
+						null => 0,
+					};
 			}
 
 			var hash = MD5Checksum.ComputeDigestHex(buffer.ToArray());

diff --git a/src/BizHawk.Emulation.DiscSystem/DiscHasher.cs b/src/BizHawk.Emulation.DiscSystem/DiscHasher.cs
@@ -1,3 +1,7 @@
+#nullable enable
+
+using System.Collections.Generic;
+using System.Text;
 using BizHawk.Common;
 using BizHawk.Common.BufferExtensions;
 
@@ -12,6 +16,16 @@ public DiscHasher(Disc disc)
 
 		private readonly Disc disc;
 
+		public string CalculateBizHash(DiscType discType)
+		{
+			return discType switch
+			{
+				DiscType.SonyPSX => Calculate_PSX_BizIDHash(),
+				DiscType.JaguarCD => CalculateRAJaguarHash() ?? "",
+				_ => OldHash(),
+			};
+		}
+
 		/// <summary>
 		/// calculates the hash for quick PSX Disc identification
 		/// </summary>
@@ -87,18 +101,131 @@ public string OldHash()
 		{
 			var buffer = new byte[512 * 2352];
 			var dsr = new DiscSectorReader(disc);
-			foreach (var track in disc.Session1.Tracks)
+			// don't hash generated lead-in and lead-out tracks
+			for (int i = 1; i <= disc.Session1.InformationTrackCount; i++)
 			{
+				var track = disc.Session1.Tracks[i];
+
 				if (track.IsAudio)
 					continue;
 
-				var lba_len = Math.Min(track.NextTrack.LBA, 512);
+				var lba_len = Math.Min(track.NextTrack.LBA - track.LBA, 512);
 				for (var s = 0; s < 512 && s < lba_len; s++)
 					dsr.ReadLBA_2352(track.LBA + s, buffer, s * 2352);
 
 				return MD5Checksum.ComputeDigestHex(buffer.AsSpan(start: 0, length: lba_len * 2352));
 			}
 			return "no data track found";
 		}
+
+		/// <summary>
+		/// Calculate Jaguar CD hash according to RetroAchievements logic
+		/// </summary>
+		public string? CalculateRAJaguarHash()
+		{
+			if (disc.Sessions.Count <= 2)
+			{
+				return null;
+			}
+
+			var dsr = new DiscSectorReader(disc)
+			{
+				Policy = { DeterministicClearBuffer = false } // let's make this a little faster
+			};
+
+			static string? HashJaguar(DiscTrack bootTrack, DiscSectorReader dsr, bool commonHomebrewHash)
+			{
+				const string _jaguarHeader = "ATARI APPROVED DATA HEADER ATRI";
+				const string _jaguarBSHeader = "TARA IPARPVODED TA AEHDAREA RT";
+				var buffer = new List<byte>();
+				var buf2352 = new byte[2352];
+
+				// find the boot track header
+				// see https://github.com/TASEmulators/BizHawk/blob/f29113287e88c6a644dbff30f92a9833307aad20/waterbox/virtualjaguar/src/cdhle.cpp#L109-L145
+				var startLba = bootTrack.LBA;
+				var numLbas = bootTrack.NextTrack.LBA - bootTrack.LBA;
+				int bootLen = 0, bootLba = 0, bootOff = 0;
+				bool byteswapped = false, foundHeader = false;
+				var bootLenOffset = (commonHomebrewHash ? 0x40 : 0) + 32 + 4;
+				for (var i = 0; i < numLbas; i++)
+				{
+					dsr.ReadLBA_2352(startLba + i, buf2352, 0);
+
+					for (var j = 0; j < 2352 - bootLenOffset - 4; j++)
+					{
+						if (buf2352[j] == _jaguarHeader[0])
+						{
+							if (_jaguarHeader == Encoding.ASCII.GetString(buf2352, j, 32 - 1))
+							{
+								bootLen = (buf2352[j + bootLenOffset + 0] << 24) | (buf2352[j + bootLenOffset + 1] << 16) |
+									(buf2352[j + bootLenOffset + 2] << 8) | buf2352[j + bootLenOffset + 3];
+								bootLba = startLba + i;
+								bootOff = j + bootLenOffset + 4;
+								// byteswapped = false;
+								foundHeader = true;
+								break;
+							}
+						}
+						else if (buf2352[j] == _jaguarBSHeader[0])
+						{
+							if (_jaguarBSHeader == Encoding.ASCII.GetString(buf2352, j, 32 - 2))
+							{
+								bootLen = (buf2352[j + bootLenOffset + 1] << 24) | (buf2352[j + bootLenOffset + 0] << 16) |
+									(buf2352[j + bootLenOffset + 3] << 8) | buf2352[j + bootLenOffset + 2];
+								bootLba = startLba + i;
+								bootOff = j + bootLenOffset + 4;
+								byteswapped = true;
+								foundHeader = true;
+								break;
+							}
+						}
+					}
+
+					if (foundHeader)
+					{
+						break;
+					}
+				}
+
+				if (!foundHeader)
+				{
+					return null;
+				}
+
+				dsr.ReadLBA_2352(bootLba++, buf2352, 0);
+
+				if (byteswapped)
+				{
+					EndiannessUtils.MutatingByteSwap16(buf2352.AsSpan());
+				}
+
+				buffer.AddRange(new ArraySegment<byte>(buf2352, bootOff, Math.Min(2352 - bootOff, bootLen)));
+				bootLen -= 2352 - bootOff;
+
+				while (bootLen > 0)
+				{
+					dsr.ReadLBA_2352(bootLba++, buf2352, 0);
+
+					if (byteswapped)
+					{
+						EndiannessUtils.MutatingByteSwap16(buf2352.AsSpan());
+					}
+
+					buffer.AddRange(new ArraySegment<byte>(buf2352, 0, Math.Min(2352, bootLen)));
+					bootLen -= 2352;
+				}
+
+				return MD5Checksum.ComputeDigestHex(buffer.ToArray());
+			}
+
+			var jaguarHash = HashJaguar(disc.Sessions[2].Tracks[1], dsr, false);
+
+			if (jaguarHash is "254487B59AB21BC005338E85CBF9FD2F") // see https://github.com/RetroAchievements/rcheevos/pull/234
+			{
+				jaguarHash = HashJaguar(disc.Sessions[1].Tracks[2], dsr, true);
+			}
+
+			return jaguarHash;
+		}
 	}
 }