Implement new signature verification

Author: xPaw

Misc/VPK.bt

@@ -213,15 +213,28 @@ typedef struct {
 
 // Signature Section
 typedef struct {
-    int PublicKeySize <comment="Size of public key">;
+    int PublicKeySize <comment="Size of public key or magic number">;
+
+    // New format with magic number
+    if (PublicKeySize == VPK_MAGIC) {
+        uint SignatureType <comment="Signature format version (0=RSALegacy, 1=RSA4096)">;
+        int ActualPublicKeySize <comment="Actual size of public key">;
+        int SignatureSize <comment="Size of signature">;
+        int Reserved <comment="Reserved field">;
+
+        if (ActualPublicKeySize > 0 && SignatureSize > 0) {
+            ubyte PublicKey[ActualPublicKeySize] <comment="Public key data">;
+            ubyte Signature[SignatureSize] <comment="Signature data">;
+        }
+        return;
+    }
 
-    // CS2 has a special case where SignatureSectionSize is 20 and PublicKeySize equals MAGIC
-    if (header.SignatureSectionSize == 20 && PublicKeySize == VPK_MAGIC) {
-        // CS2 special case - just skip the rest
-        ubyte Padding[16];
+    // Old format - check for empty signature section
+    if (header.SignatureSectionSize == 20) {
         return;
     }
 
+    // Old format with data
     if (PublicKeySize > 0) {
         ubyte PublicKey[PublicKeySize] <comment="Public key data">;
     }

ValvePak/ValvePak.Test/Files/cs2_new_signature_actually_signed.vpk

@@ -67,7 +67,7 @@ public void FindEntryDeep()
 			using var package = new Package();
 			package.Read(path);
 
-			Assert.Multiple(() =>
+			using (Assert.EnterMultipleScope())
 			{
 				Assert.That(package.FindEntry("addons\\chess\\chess.vdf")?.CRC32, Is.EqualTo(0xA4115395));
 				Assert.That(package.FindEntry("addons/chess\\chess.vdf")?.CRC32, Is.EqualTo(0xA4115395));
@@ -78,7 +78,7 @@ public void FindEntryDeep()
 				Assert.That(package.FindEntry("\\addons/hello_github_reader/chess.vdf"), Is.Null);
 				Assert.That(package.FindEntry(string.Empty), Is.Null);
 				Assert.That(package.FindEntry(" "), Is.Null);
-			});
+			}
 		}
 
 		[Test]
@@ -90,7 +90,7 @@ public void TestBinarySearch()
 			package.OptimizeEntriesForBinarySearch();
 			package.Read(path);
 
-			Assert.Multiple(() =>
+			using (Assert.EnterMultipleScope())
 			{
 				Assert.That(package.FindEntry("addons\\chess\\chess.vdf")?.CRC32, Is.EqualTo(0xA4115395));
 				Assert.That(package.FindEntry("addons/chess\\chess.vdf")?.CRC32, Is.EqualTo(0xA4115395));
@@ -101,7 +101,7 @@ public void TestBinarySearch()
 				Assert.That(package.FindEntry("\\addons/hello_github_reader/chess.vdf"), Is.Null);
 				Assert.That(package.FindEntry(string.Empty), Is.Null);
 				Assert.That(package.FindEntry(" "), Is.Null);
-			});
+			}
 
 			foreach (var extension in package.Entries!.Values)
 			{
@@ -121,7 +121,7 @@ public void TestBinarySearchCaseInsensitive()
 			package.OptimizeEntriesForBinarySearch(StringComparison.OrdinalIgnoreCase);
 			package.Read(path);
 
-			Assert.Multiple(() =>
+			using (Assert.EnterMultipleScope())
 			{
 				Assert.That(package.FindEntry("ADDONS\\chess\\chess.vdf")?.CRC32, Is.EqualTo(0xA4115395));
 				Assert.That(package.FindEntry("addons/CHESS\\chess.vdf")?.CRC32, Is.EqualTo(0xA4115395));
@@ -131,7 +131,7 @@ public void TestBinarySearchCaseInsensitive()
 
 				Assert.That(package.FindEntry("\\addons/CHESS/hello_github_reader.vdf"), Is.Null);
 				Assert.That(package.FindEntry("\\addons/hello_github_reader/CHESS.vdf"), Is.Null);
-			});
+			}
 
 			foreach (var extension in package.Entries!.Values)
 			{
@@ -150,13 +150,13 @@ public void FindEntryRoot()
 			using var package = new Package();
 			package.Read(path);
 
-			Assert.Multiple(() =>
+			using (Assert.EnterMultipleScope())
 			{
 				Assert.That(package.FindEntry("kitten.jpg")?.CRC32, Is.EqualTo(0x9C800116));
 				Assert.That(package.FindEntry("\\kitten.jpg")?.CRC32, Is.EqualTo(0x9C800116));
 				Assert.That(package.FindEntry("/kitten.jpg")?.CRC32, Is.EqualTo(0x9C800116));
 				Assert.That(package.FindEntry("\\/kitten.jpg")?.CRC32, Is.EqualTo(0x9C800116));
-			});
+			}
 		}
 
 		[Test]
@@ -206,7 +206,7 @@ public void FindEntrySpacesAndExtensionless()
 			using var package = new Package();
 			package.Read(path);
 
-			Assert.Multiple(() =>
+			using (Assert.EnterMultipleScope())
 			{
 				Assert.That(package.FindEntry("test")?.CRC32, Is.EqualTo(0x0BA144CC));
 				Assert.That(package.FindEntry("folder with space/test")?.CRC32, Is.EqualTo(0xBF108706));
@@ -218,7 +218,7 @@ public void FindEntrySpacesAndExtensionless()
 				Assert.That(package.FindEntry("uppercasefolder/UpperCaseFile.txt"), Is.Null);
 				Assert.That(package.FindEntry("uppercasefolder/bad_file_forfun.TXT"), Is.Null);
 				Assert.That(package.FindEntry("uppercasefolder/bad_file_forfun.txt2"), Is.Null);
-			});
+			}
 		}
 
 		[Test]
@@ -258,7 +258,7 @@ public void TestGetFullPath()
 			using var package = new Package();
 			package.Read(path);
 
-			Assert.Multiple(() =>
+			using (Assert.EnterMultipleScope())
 			{
 				Assert.That(package.FindEntry("test")?.GetFullPath(), Is.EqualTo("test"));
 				Assert.That(package.FindEntry("folder with space/test")?.GetFullPath(), Is.EqualTo("folder with space/test"));
@@ -270,7 +270,7 @@ public void TestGetFullPath()
 				Assert.That(package.FindEntry("folder with space/test")?.GetFileName(), Is.EqualTo("test"));
 				Assert.That(package.FindEntry("folder with space\\space_extension. txt")?.GetFileName(), Is.EqualTo("space_extension. txt"));
 				Assert.That(package.FindEntry("uppercasefolder/bad_file_forfun.txt")?.GetFileName(), Is.EqualTo("bad_file_forfun.txt"));
-			});
+			}
 		}
 
 		[Test]
@@ -281,14 +281,14 @@ public void TestPackageEntryToString()
 			using var package = new Package();
 			package.Read(path);
 
-			Assert.Multiple(() =>
+			using (Assert.EnterMultipleScope())
 			{
 				Assert.That(package.FindEntry("test")?.ToString(), Is.EqualTo("test crc=0xba144cc metadatasz=0 fnumber=0 ofs=0x00 sz=39"));
 				Assert.That(package.FindEntry("folder with space/test")?.ToString(), Is.EqualTo("folder with space/test crc=0xbf108706 metadatasz=0 fnumber=0 ofs=0x52 sz=41"));
 				Assert.That(package.FindEntry("folder with space\\space_extension. txt")?.ToString(), Is.EqualTo("folder with space/space_extension. txt crc=0x9321fc0 metadatasz=0 fnumber=0 ofs=0x7b sz=30"));
 				Assert.That(package.FindEntry("uppercasefolder/bad_file_forfun.txt")?.ToString(), Is.EqualTo("uppercasefolder/bad_file_forfun.txt crc=0x15c1490f metadatasz=0 fnumber=0 ofs=0xa2 sz=2"));
 				Assert.That(package.FindEntry("UpperCaseFolder/UpperCaseFile.txt")?.ToString(), Is.EqualTo("UpperCaseFolder/UpperCaseFile.txt crc=0x32cff012 metadatasz=0 fnumber=0 ofs=0x27 sz=43"));
-			});
+			}
 		}
 
 		[Test]
@@ -315,7 +315,7 @@ public void TestFileReadWithPreloadedBytes()
 
 			package.ReadEntry(file, out var allBytes);
 
-			Assert.Multiple(() =>
+			using (Assert.EnterMultipleScope())
 			{
 				Assert.That(file.ToString(), Is.EqualTo("lorem.txt crc=0xf2cafa54 metadatasz=56 fnumber=32767 ofs=0x00 sz=588"));
 				Assert.That(file.CRC32, Is.EqualTo(0xF2CAFA54));
@@ -330,7 +330,7 @@ public void TestFileReadWithPreloadedBytes()
 					"faucibus erat, vel fringilla purus scelerisque tempor. Proin feugiat blandit sapien eget tempus. Praesent gravida in " +
 					"risus a accumsan. Praesent egestas tincidunt dui nec laoreet. Sed ac lacus non tortor consectetur consectetur a ac " +
 					"lacus. In rhoncus turpis a nisl volutpat, nec cursus urna tincidunt.\n")));
-			});
+			}
 		}
 
 		[Test]
@@ -395,7 +395,7 @@ public void TestFileChecksums()
 		}
 
 		[Test]
-		public void ParsesCS2VPKWithInvalidSignature()
+		public void ParsesCS2VPKWithRSA4096Signature()
 		{
 			var path = Path.Combine(TestContext.CurrentContext.TestDirectory, "Files", "cs2_new_signature.vpk");
 
@@ -404,12 +404,34 @@ public void ParsesCS2VPKWithInvalidSignature()
 
 			package.VerifyHashes();
 
-			Assert.Multiple(() =>
+			using (Assert.EnterMultipleScope())
 			{
 				Assert.That(package.Signature, Is.Null);
 				Assert.That(package.PublicKey, Is.Null);
+				Assert.That(package.SignatureType, Is.EqualTo(ESignatureType.OnlyFileChecksum));
+				Assert.That(package.IsSignatureValid(), Is.True);
+			}
+		}
+
+		[Test]
+		public void ReadCSGOPak01WithRSA4096Signature()
+		{
+			var path = Path.Combine(TestContext.CurrentContext.TestDirectory, "Files", "cs2_new_signature_actually_signed.vpk");
+
+			using var package = new Package();
+			package.Read(path);
+
+			package.VerifyHashes();
+
+			using (Assert.EnterMultipleScope())
+			{
+				Assert.That(package.SignatureType, Is.EqualTo(ESignatureType.OnlyFileChecksum));
+				Assert.That(package.PublicKey, Is.Not.Null);
+				Assert.That(package.Signature, Is.Not.Null);
+				Assert.That(package.PublicKey!, Has.Length.EqualTo(550));
+				Assert.That(package.Signature!, Has.Length.EqualTo(512));
 				Assert.That(package.IsSignatureValid(), Is.True);
-			});
+			}
 		}
 
 		[Test]
@@ -538,20 +560,20 @@ private static void TestVPKExtraction(string path)
 				}
 			}
 
-			Assert.Multiple(() =>
+			using (Assert.EnterMultipleScope())
 			{
 				Assert.That(data, Has.Count.EqualTo(3));
 				Assert.That(data["kitten.jpg"], Is.EqualTo("1C03B452FEE5274B0BC1FA1A866EE6C8FA0D43AA464C6BCFB3AB531F6E813081"));
 				Assert.That(data["steammessages_base.proto"], Is.EqualTo("FCC96AE59EE6BB9EEC4E16A50C928EFD3FB16E1CCA49E38BD2FA8391AB7936BE"));
 				Assert.That(data["steammessages_clientserver.proto"], Is.EqualTo("1F90C38527D0853B4713942668F2DC83F433DBE919C002825A4526138A200428"));
-			});
+			}
 
-			Assert.Multiple(() =>
+			using (Assert.EnterMultipleScope())
 			{
 				Assert.That(flatEntries["kitten"].TotalLength, Is.EqualTo(16361));
 				Assert.That(flatEntries["steammessages_base"].TotalLength, Is.EqualTo(2563));
 				Assert.That(flatEntries["steammessages_clientserver"].TotalLength, Is.EqualTo(39177));
-			});
+			}
 		}
 	}
 }

ValvePak/ValvePak.Test/PackageTest.cs

@@ -42,21 +42,21 @@ public void CreateNewPackage()
 			var newEntry = packageWritten.FindEntry(newName);
 
 			Assert.That(newEntry, Is.Not.Null);
-			Assert.Multiple(() =>
+			using (Assert.EnterMultipleScope())
 			{
 				Assert.That(newEntry.CRC32, Is.EqualTo(0x9C800116));
 				Assert.That(newEntry.ArchiveIndex, Is.EqualTo(0x7FFF));
 				Assert.That(newEntry.DirectoryName, Is.EqualTo("path/to"));
 				Assert.That(newEntry.TypeName, Is.EqualTo("jpg"));
 				Assert.That(newEntry.FileName, Is.EqualTo("cool kitty"));
-			});
+			}
 
 			packageWritten.ReadEntry(newEntry, out var newFileData);
-			Assert.Multiple(() =>
+			using (Assert.EnterMultipleScope())
 			{
 				Assert.That(newFileData, Is.EqualTo(fileData));
 				Assert.That(packageWritten.FindEntry("valvepak")!.CRC32, Is.EqualTo(0xF14F273C));
-			});
+			}
 		}
 
 		[Test]
@@ -92,74 +92,77 @@ public void AddAndRemoveFiles()
 			package.AddFile("test3.txt", []);
 			package.AddFile("test4.txt", []);
 
-			Assert.That(package.Entries!.ContainsKey("txt"), Is.True);
-			Assert.That(package.Entries["txt"], Has.Count.EqualTo(4));
-			Assert.That(package.RemoveFile(package.FindEntry("test2.txt")!), Is.True);
-			Assert.That(package.FindEntry("test2.txt"), Is.Null);
-			Assert.That(package.FindEntry("test1.txt"), Is.Not.Null);
-			Assert.That(package.RemoveFile(new PackageEntry
+			using (Assert.EnterMultipleScope())
 			{
-				FileName = "test5",
-				TypeName = "txt",
-				DirectoryName = " ",
-			}), Is.False);
-			Assert.That(package.Entries["txt"], Has.Count.EqualTo(3));
-			Assert.That(package.RemoveFile(package.FindEntry("test4.txt")!), Is.True);
-			Assert.That(package.RemoveFile(package.FindEntry("test3.txt")!), Is.True);
-			Assert.That(package.RemoveFile(package.FindEntry("test1.txt")!), Is.True);
-			Assert.That(package.Entries, Is.Empty);
+				Assert.That(package.Entries!.ContainsKey("txt"), Is.True);
+				Assert.That(package.Entries["txt"], Has.Count.EqualTo(4));
+				Assert.That(package.RemoveFile(package.FindEntry("test2.txt")!), Is.True);
+				Assert.That(package.FindEntry("test2.txt"), Is.Null);
+				Assert.That(package.FindEntry("test1.txt"), Is.Not.Null);
+				Assert.That(package.RemoveFile(new PackageEntry
+				{
+					FileName = "test5",
+					TypeName = "txt",
+					DirectoryName = " ",
+				}), Is.False);
+				Assert.That(package.Entries["txt"], Has.Count.EqualTo(3));
+				Assert.That(package.RemoveFile(package.FindEntry("test4.txt")!), Is.True);
+				Assert.That(package.RemoveFile(package.FindEntry("test3.txt")!), Is.True);
+				Assert.That(package.RemoveFile(package.FindEntry("test1.txt")!), Is.True);
+				Assert.That(package.Entries, Is.Empty);
+			}
 		}
 
 		[Test]
 		public void SetsSpaces()
 		{
 			using var package = new Package();
 			var file = package.AddFile("", []);
-			Assert.Multiple(() =>
+			using (Assert.EnterMultipleScope())
 			{
 				Assert.That(file.TypeName, Is.EqualTo(" "));
 				Assert.That(file.DirectoryName, Is.EqualTo(" "));
 				Assert.That(file.FileName, Is.EqualTo(""));
 				Assert.That(package.Entries!.ContainsKey(" "), Is.True);
 				Assert.That(package.Entries[" "][0], Is.EqualTo(file));
-			});
+			}
 
 			var file2 = package.AddFile("hello", []);
-			Assert.Multiple(() =>
+			using (Assert.EnterMultipleScope())
 			{
 				Assert.That(file2.TypeName, Is.EqualTo(" "));
 				Assert.That(file2.DirectoryName, Is.EqualTo(" "));
 				Assert.That(file2.FileName, Is.EqualTo("hello"));
-			});
+			}
 
 			var file3 = package.AddFile("hello.txt", []);
-			Assert.Multiple(() =>
+			using (Assert.EnterMultipleScope())
 			{
 				Assert.That(file3.TypeName, Is.EqualTo("txt"));
 				Assert.That(file3.DirectoryName, Is.EqualTo(" "));
 				Assert.That(file3.FileName, Is.EqualTo("hello"));
-			});
+			}
 
 			var file4 = package.AddFile("folder/hello", []);
-			Assert.Multiple(() =>
+			using (Assert.EnterMultipleScope())
 			{
 				Assert.That(file4.TypeName, Is.EqualTo(" "));
 				Assert.That(file4.DirectoryName, Is.EqualTo("folder"));
 				Assert.That(file4.FileName, Is.EqualTo("hello"));
-			});
+			}
 		}
 
 		[Test]
 		public void NormalizesSlashes()
 		{
 			using var package = new Package();
 			var file = package.AddFile("a/b\\c\\d.txt", []);
-			Assert.Multiple(() =>
+			using (Assert.EnterMultipleScope())
 			{
 				Assert.That(file.TypeName, Is.EqualTo("txt"));
 				Assert.That(file.DirectoryName, Is.EqualTo("a/b/c"));
 				Assert.That(file.FileName, Is.EqualTo("d"));
-			});
+			}
 		}
 	}
 }

ValvePak/ValvePak.Test/WriteTest.cs

@@ -0,0 +1,23 @@
+namespace SteamDatabase.ValvePak
+{
+	/// <summary>
+	/// Represents the signature type used in VPK archives.
+	/// </summary>
+	public enum ESignatureType
+	{
+		/// <summary>
+		/// Type not yet determined.
+		/// </summary>
+		Unknown = -1,
+
+		/// <summary>
+		/// RSA legacy signature format.
+		/// </summary>
+		FullFile = 0,
+
+		/// <summary>
+		/// RSA-4096 signature format (version 1).
+		/// </summary>
+		OnlyFileChecksum = 1,
+	}
+}