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Plugins: Simplify event data; add GetStrings and GetStringLiterals

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This commit is contained in:
Katy Coe
2020-12-21 22:54:01 +01:00
parent fbc8e0950c
commit 3e27cd25e9
5 changed files with 112 additions and 79 deletions
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98
Il2CppInspector.Common/IL2CPP/Metadata.cs
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@@ -43,7 +43,7 @@ namespace Il2CppInspector
public uint[] VTableMethodIndices { get; set; }
public string[] StringLiterals { get; set; }
public Dictionary<int, string> Strings { get; } = new Dictionary<int, string>();
public Dictionary<int, string> Strings { get; private set; } = new Dictionary<int, string>();
// Set if something in the metadata has been modified / decrypted
public bool IsModified { get; private set; } = false;
@@ -97,7 +97,7 @@ namespace Il2CppInspector
// in the header after the sanity and version fields, and since it will always point directly to the first byte after the end of the header,
// we can use this value to determine the actual header length and therefore narrow down the metadata version to 24.0/24.1 or 24.2.
if (!pluginResult.AdditionalData.SkipValidation) {
if (!pluginResult.SkipValidation) {
var realHeaderLength = Header.stringLiteralOffset;
if (realHeaderLength != Sizeof(typeof(Il2CppGlobalMetadataHeader))) {
@@ -169,15 +169,20 @@ namespace Il2CppInspector
AttributeTypeRanges = ReadArray<Il2CppCustomAttributeTypeRange>(Header.attributesInfoOffset, Header.attributesInfoCount / Sizeof(typeof(Il2CppCustomAttributeTypeRange)));
}
// Get all metadata string literals
Position = Header.stringOffset;
// Get all metadata strings
var pluginGetStringsResult = PluginHooks.GetStrings(this);
if (pluginGetStringsResult.IsHandled)
Strings = pluginGetStringsResult.Strings;
// Naive implementation: this works for normal IL2CPP metadata but isn't good enough when the strings are encrypted
while (Position < Header.stringOffset + Header.stringCount)
Strings.Add((int)Position - Header.stringOffset, ReadNullTerminatedString());
else {
Position = Header.stringOffset;
// To check for encryption, find every single string start position by scanning all of the definitions
var stringOffsets =
// Naive implementation: this works for normal IL2CPP metadata but isn't good enough when the strings are encrypted
while (Position < Header.stringOffset + Header.stringCount)
Strings.Add((int) Position - Header.stringOffset, ReadNullTerminatedString());
// To check for encryption, find every single string start position by scanning all of the definitions
var stringOffsets =
Images.Select(x => x.nameIndex)
.Concat(Assemblies.Select(x => x.aname.nameIndex))
.Concat(Assemblies.Select(x => x.aname.cultureIndex))
@@ -195,50 +200,57 @@ namespace Il2CppInspector
.Distinct()
.ToList();
// Now confirm that all the keys are present
// If they aren't, that means one or more of the null terminators wasn't null, indicating potential encryption
// Only do this if we need to because it's very slow
if (Header.stringCount > 0 && stringOffsets.Except(Strings.Keys).Any()) {
// Now confirm that all the keys are present
// If they aren't, that means one or more of the null terminators wasn't null, indicating potential encryption
// Only do this if we need to because it's very slow
if (Header.stringCount > 0 && stringOffsets.Except(Strings.Keys).Any()) {
Console.WriteLine("Decrypting strings...");
StatusUpdate("Decrypting strings");
Console.WriteLine("Decrypting strings...");
StatusUpdate("Decrypting strings");
// There may be zero-padding at the end of the last string since counts seem to be word-aligned
// Find the true location one byte after the final character of the final string
var endOfStrings = Header.stringCount;
while (ReadByte(Header.stringOffset + endOfStrings - 1) == 0)
endOfStrings--;
// There may be zero-padding at the end of the last string since counts seem to be word-aligned
// Find the true location one byte after the final character of the final string
var endOfStrings = Header.stringCount;
while (ReadByte(Header.stringOffset + endOfStrings - 1) == 0)
endOfStrings--;
// Start again
Strings.Clear();
Position = Header.stringOffset;
// Start again
Strings.Clear();
Position = Header.stringOffset;
// Read in all of the strings as if they are fixed length rather than null-terminated
foreach (var offset in stringOffsets.Zip(stringOffsets.Skip(1).Append(endOfStrings), (a, b) => (current: a, next: b))) {
var encryptedString = ReadBytes(offset.next - offset.current - 1);
// Read in all of the strings as if they are fixed length rather than null-terminated
foreach (var offset in stringOffsets.Zip(stringOffsets.Skip(1).Append(endOfStrings), (a, b) => (current: a, next: b))) {
var encryptedString = ReadBytes(offset.next - offset.current - 1);
// The null terminator is the XOR key
var xorKey = ReadByte();
// The null terminator is the XOR key
var xorKey = ReadByte();
var decryptedString = Encoding.GetString(encryptedString.Select(b => (byte) (b ^ xorKey)).ToArray());
Strings.Add(offset.current, decryptedString);
var decryptedString = Encoding.GetString(encryptedString.Select(b => (byte) (b ^ xorKey)).ToArray());
Strings.Add(offset.current, decryptedString);
}
// Write changes back in case the user wants to save the metadata file
Position = Header.stringOffset;
foreach (var str in Strings.OrderBy(s => s.Key))
WriteNullTerminatedString(str.Value);
Flush();
IsModified = true;
}
// Write changes back in case the user wants to save the metadata file
Position = Header.stringOffset;
foreach (var str in Strings.OrderBy(s => s.Key))
WriteNullTerminatedString(str.Value);
Flush();
IsModified = true;
}
// Get all managed code string literals
var stringLiteralList = ReadArray<Il2CppStringLiteral>(Header.stringLiteralOffset, Header.stringLiteralCount / Sizeof(typeof(Il2CppStringLiteral)));
// Get all string literals
var pluginGetStringLiteralsResult = PluginHooks.GetStringLiterals(this);
if (pluginGetStringLiteralsResult.IsHandled)
StringLiterals = pluginGetStringLiteralsResult.StringLiterals.ToArray();
StringLiterals = new string[stringLiteralList.Length];
for (var i = 0; i < stringLiteralList.Length; i++)
StringLiterals[i] = ReadFixedLengthString(Header.stringLiteralDataOffset + stringLiteralList[i].dataIndex, stringLiteralList[i].length);
else {
var stringLiteralList = ReadArray<Il2CppStringLiteral>(Header.stringLiteralOffset, Header.stringLiteralCount / Sizeof(typeof(Il2CppStringLiteral)));
StringLiterals = new string[stringLiteralList.Length];
for (var i = 0; i < stringLiteralList.Length; i++)
StringLiterals[i] = ReadFixedLengthString(Header.stringLiteralDataOffset + stringLiteralList[i].dataIndex, stringLiteralList[i].length);
}
// Post-processing hook
IsModified |= PluginHooks.PostProcessMetadata(this).IsStreamModified;