public static string ReplaceRegion(string existingCode, string regionName, string newCode)
{
var syntaxTree = CSharpSyntaxTree.ParseText(existingCode);
var region = CodeMutator.GetRegion(syntaxTree, regionName);
if (region == null)
{
throw new Exception($"Cannot find region named {regionName}");
}
return
(existingCode
.Substring(0, region.Begin.FullSpan.End) +
newCode +
Environment.NewLine +
existingCode
.Substring(region.End.FullSpan.Start));
}
static RegionInfo GetRegion(SyntaxTree syntaxTree, string regionName) => CodeMutator.GetRegions(syntaxTree) .FirstOrDefault(x => x.Name == regionName);
// Mutates all blocks in the given method CFG.
private void mutateBlocks(MethodCfg methodCfg)
{
var manipulator = new CfgManipulator(this.module, this.host, this.logger, methodCfg);
var codeMutator = new CodeMutator(this.module, this.host, this.logger, this.prng, methodCfg, manipulator, this.debugging);
codeMutator.mutateBlocks(methodCfg.basicBlocks);
}
// Searches semantically equivalent blocks in the given method CFG and obfuscates them.
private void obfuscateSemanticallyEquivalentBlocks(MethodCfg methodCfg)
{
// Group all blocks with same semantic ID.
var semanticGroups = new Dictionary<int, List<BasicBlock>>();
foreach(var block in methodCfg.basicBlocks) {
List<BasicBlock> blockList = null;
if(!semanticGroups.TryGetValue(block.semanticId, out blockList)) {
blockList = new List<BasicBlock>();
semanticGroups[block.semanticId] = blockList;
}
if(block.semanticId != -1) {
semanticGroups[block.semanticId].Add(block);
}
}
// Mutate equivalent blocks.
var manipulator = new CfgManipulator(this.module, this.host, this.logger, methodCfg);
var codeMutator = new CodeMutator(this.module, this.host, this.logger, this.prng, methodCfg, manipulator, this.debugging);
foreach(var blockList in semanticGroups.Values) {
codeMutator.mutateSemanticallyEquivalentBlocks(blockList);
}
}
