public static bool Patch(IAssetsFileProvider apk, FilePatch patch)
{
string binaryFile = patch.Filename;
if (!apk.FileExists(binaryFile))
{
Console.WriteLine("Binary file to patch doesn't exist in the APK!");
return(false);
}
byte[] binaryBytes = apk.Read(binaryFile);
if (binaryBytes.Length != patch.ExpectedFileSize)
{
Console.WriteLine("Binary file to patch is the wrong length!");
return(false);
}
List <Patch> toApply = new List <Patch>();
Console.WriteLine("Verifying patches binary...");
using (MemoryStream msBinary = new MemoryStream(binaryBytes))
{
//verify each of the patches can be applied or already are applied
foreach (Patch p in patch.Patches)
{
msBinary.Seek(p.Address, SeekOrigin.Begin);
byte[] readVals = new byte[p.ExpectedData.Count];
msBinary.Read(readVals, 0, p.ExpectedData.Count);
if (!readVals.SequenceEqual(p.ExpectedData))
{
msBinary.Seek(p.Address, SeekOrigin.Begin);
readVals = new byte[p.PatchData.Count];
msBinary.Read(readVals, 0, p.PatchData.Count);
if (readVals.SequenceEqual(p.PatchData))
{
Console.WriteLine($"Patch {p.Name} already appears to be applied.");
continue;
}
else
{
Console.WriteLine($"Patch {p.Name} can't be applied to this binary, the code at the patch location doesn't match what was expected. Aborting any patching...");
//if one patch can't be applied, abort the whole thing
return(false);
}
}
}
foreach (Patch p in toApply)
{
msBinary.Seek(p.Address, SeekOrigin.Begin);
msBinary.Write(p.PatchData.ToArray(), 0, p.PatchData.Count);
}
msBinary.Seek(0, SeekOrigin.Begin);
apk.Write(binaryFile, msBinary.ToArray(), true, true);
}
Console.WriteLine("Done patching binary!");
return(true);
}
public static void WriteCombinedAssets(this IAssetsFileProvider fp, AssetsFile assetsFile, string assetsFilePath)
{
if (assetsFilePath.EndsWith("split0"))
{
throw new ArgumentException("Don't pass in filenames with split0, pass in the original.");
}
fp.DeleteFiles(assetsFilePath + ".split*");
using (var ms = new MemoryStream())
{
assetsFile.Write(ms);
ms.Seek(0, SeekOrigin.Begin);
fp.Write(assetsFilePath, ms.ToArray(), true, true);
}
}
public void Sign(IAssetsFileProvider fileProvider)
{
MemoryStream msManifestFile = new MemoryStream();
MemoryStream msSigFile = new MemoryStream();
byte[] keyBlock;
MemoryStream msSignatureFileBody = new MemoryStream();
try
{
//create the MF file header
using (StreamWriter swManifest = GetSW(msManifestFile))
{
swManifest.WriteLine("Manifest-Version: 1.0");
swManifest.WriteLine("Created-By: emulamer");
swManifest.WriteLine();
}
//so that we can do it in one pass, write the MF and SF line items at the same time to their respective streams
foreach (var infFile in fileProvider.FindFiles("*").Where(x => !x.StartsWith("META-INF")))
{
WriteEntryHashes(fileProvider, infFile, msManifestFile, msSignatureFileBody);
}
//compute the hash on the entirety of the manifest file for the SF file
msManifestFile.Seek(0, SeekOrigin.Begin);
var manifestFileHash = _sha.ComputeHash(msManifestFile);
//write the SF to memory then copy it out to the actual file- contents will be needed later to use for signing, don't want to hit the zip stream twice
byte[] sigFileBytes = null;
using (StreamWriter swSignatureFile = GetSW(msSigFile))
{
swSignatureFile.WriteLine("Signature-Version: 1.0");
swSignatureFile.WriteLine($"SHA1-Digest-Manifest: {Convert.ToBase64String(manifestFileHash)}");
swSignatureFile.WriteLine("Created-By: emulamer");
swSignatureFile.WriteLine();
}
msSignatureFileBody.Seek(0, SeekOrigin.Begin);
msSignatureFileBody.CopyTo(msSigFile);
msSigFile.Seek(0, SeekOrigin.Begin);
sigFileBytes = msSigFile.ToArray();
//get the key block (all the hassle distilled into one line), then write it out to the RSA file
keyBlock = SignIt(sigFileBytes);
//delete all the META-INF stuff that exists already
fileProvider.DeleteFiles("META-INF*");
//write the 3 files
msManifestFile.Seek(0, SeekOrigin.Begin);
fileProvider.Write("META-INF/MANIFEST.MF", msManifestFile.ToArray(), true, true);
fileProvider.Write("META-INF/BS.SF", sigFileBytes, true, true);
fileProvider.Write("META-INF/BS.RSA", keyBlock, true, true);
fileProvider.Save();
}
finally
{
if (msManifestFile != null)
{
msManifestFile.Dispose();
}
if (msSignatureFileBody != null)
{
msSignatureFileBody.Dispose();
}
if (msManifestFile != null)
{
msManifestFile.Dispose();
}
if (msSigFile != null)
{
msSigFile.Dispose();
}
}
}